TOPIC№1: Acquired intestinal ileus.

(Adhesive Intestinal Obstruction, intussusception, and dynamic intestinal obstruction).

Digestive tract bleeding in children. Portal hypertension.

(Peptic ulcer Disease, Portal Hypertension, Meckel’s diverticulum bleeding, Colonic polyposis, Anal Fissure, Hemorrhoids).

Plan:

1.    Acquired intestinal ileus:

1.1.      Adhesive Intestinal Obstruction.

1.2.      Intussusception.

1.3.      Dynamic intestinal obstruction.

2.    Digestive tract bleeding in children.

2.1.      Peptic ulcer Disease.

2.2.      Meckel’s diverticulum bleeding.

2.3.      Colonic polyposis.

2.4.      Anal Fissure.

2.5.      Hemorrhoids.

3.    Portal hypertension

1. Acquired intestinal ileus.

 

1.1. Adhesive Intestinal Obstruction

Incidence

The incidence of postoperative adhesive obstruction after laparotomy is about 2%. The procedures which have highest risk for adhesive McBurney s point in pedi­atric patients are:

1. subtotal colectomy,

2. resection of symptomatic Meckel’s diverticulum,

3. Ladd’s procedure, and

4. nephrectomy

Etiology

The causes of postoperative McBurneys point include adhesions, intussuscep­tion, hernia, and tumor. Adhesions are fibrous bands of tissue that form between loops of bowel or between the bowel and the abdominal wall after intraabdominal inflammation. Obstruction occurs when the bowel is “caught” within one of these fibrous bands in a kinked or twisted position, twists around an adhesive band, or herniates between a band and another fixed structure within the abdomen.

Clinical Presentation

Children with a mechanical obstruction present with cramping abdominal pain, distension, and vomiting. For prolonged McBurneys points the vomitus becomes bilious or even feculent. Inspection of the abdomen may reveal obvious dilated loops of bowel and distension. If observed early in the clinical course, the patients vital signs are within the normal range and the abdomen is not tender. In contrast, chil­dren with compromised bowel or a prolonged obstruction, present with abdominal pain, vomiting, fever, tachycardia, decreased blood pressure, abdominal tenderness, and leukocytosis.

Diagnosis

The differential diagnosis is ileus versus mechanical obstruction. Nonsurgical, inflammatory and metabolic conditions that may result in ileus must be considered. Blood is drawn and sent for Hbg, WBC and differential, amylase (pancreatitis), liver function tests (hepatitis) and bilirubin (biliary tract disease). Urinalysis (uri­nary tract infection, nephritis, stones), blood cultures (systemic infection), and stool cultures (colitis, rotavirus) may also be indicated. Upright posteroanterior and lat­eral chest x-rays are obtained to exclude pneumonia or the presence of free intraperitoneal air. Flat and upright abdominal films are also obtained. In a child with a complete bowel obstruction, abdominal films will show dilated loops of small bowel with multiple air fluid levels and little or no air in the rectum and/or distal to the obstructing lesion. Ultrasound is occasionally useful to rule out a postoperative intussusception.

Figure. Small bowel obstruction – CT. Typical case of small bowel obstruction due to adhesions Note the dilated small bowel loops with a focal transition zone to distal collapsed bowel (arrow).

 

Treatment

Nonoperative management includes resuscitation with isotonic saline solutions, nasogastric decompression, correction of electrolyte abnormalities, IV antibiotics, and serial examinations. Within 24 hours, children with ileus and simple mechani­cal obstruction will improve as indicated by a return of bowel function, a normaliza­tion of vital signs and a normal WBC. Indications for operation include obstipation for 24 hours, continued abdominal pain with fever and tachycardia, decreased blood pressure, increasing abdominal tenderness, and leukocytosis despite adequate resus­citation and medical treatment.

The abdomen is opened through a previous incision, if present, and midline, if not. The cecum is identified and the collapsed ileum is followed proximally until dilated bowel and the point of obstruction is identified. The offending adhesive bands are disrupted and the abdomen is closed. Laparoscopic lysis of adhesions is another option and may allow a shorter postoperative recovery and hospital stay.

Postoperatively, nasogastric decompression and intravenous fluids are continued until return of bowel function and the volume of gastric aspirate decreases.

 

1.2. Intussusception

Intussusception, the telescoping or invagination of a proximal portion of intestine (intussusceptum) into a more distal portion (intussuscipiens), is one of the most common causes of bowel obstruction in infants and toddlers.

Intussusception was first described by Barbette in 1674, and Wilson was the first to successfully treat it surgically in 1831. In 1876, Hirschsprung first reported the technique of hydrostatic reduction, and after monitoring a series of 107 cases, reported a 35% mortality rate in 1905.

Intussusception is the telescoping or invagination of a proximal portion of intestine into a more distal portion. Vascular compromise and subsequent bowel necrosis are the primary concern with intussusception. Although uncommon, as many as 10% of patients who undergo operative reduction of intussusception may require bowel resection.

Four varieties are described: ileocolic, colocolic, ileoilealcolic and ileoileal, this latter being the least frequent.

·    Ileocolic – the small intestine invaginates into the right colon; this is the most common intussusception

·    Ileoileal – the small intestine invaginates into itself

·    ileoilealcolic

·    Colocolic – the large intestine invaginates into itself

 

 

 

 

Ileoileal or colocolic intussusceptions occur less frequently than ileocolic intussusceptions and are more often associated with a pathologic lead point.

The condition typically occurs in infants between approximately 6 months and 2 years with most cases clustered between 6 and 12 months. In most cases no lead point is identified as the cause.

Causes, pathophysiology of intussusception

Most cases (90%) are idiopathic, with no identifiable lesion acting as the lead point or pathological apex of the intussusceptum.

In infants, the causes of intussusception are unknown, although there are some theories about why it occurs. In some cases, the lingering effects of a viral intestinal infection may be to blame. Viral infections can cause bumpy swelling of the infection-fighting lymph tissue that normally lines the intestine, which then has the chance to get “stuck” inside itself as it normally moves during digestion. Because intussusception is seen most often in spring and fall, this seems to suggest a possible connection to the kinds of viruses that children catch during these seasons.

It has also been suggested (but is less likely) that an infant’s new eating habits may also be to blame: because intussusception tends to happen around the age that babies are weaned, the introduction of new foods to a young digestive system may be the cause of the problem.

Recently there has also been some investigation into the rotavirus vaccine and its possible connection to intussusception, although the number of reported cases of intussusception among babies who received the vaccine is quite small.

When an older child or adult develops intussusception, it is often the result of a Meckels diverticulum, intestinal duplication, tumor and polyps.

·                    Predisposing factors

ü Recent upper respiratory illness

ü Recent diarrheal illness

ü Henoch-Schönlein purpura

ü Cystic fibrosis

ü Chronic indwelling GI tubes

·                    Processes that result in a mechanical lead point

ü Meckel diverticulum

ü Intestinal polyp (eg, Peutz-Jeghers syndrome, familial polyposis coli, juvenile polyposis)

ü Intestinal lymphosarcoma

ü Blunt abdominal trauma with intestinal or mesenteric hematomas

ü Hemangioma

ü Foreign body

ü Henoch-Schönlein purpura (small bowel hematomas cause small bowel intussusception)

 

Frequency. The incidence of intussusception is 1.5-4 cases per 1000 live births, with a male-to-female ratio of 3:2. With advancing age, gender difference becomes marked; in patients older than 4 years, the male-to-female ratio is 8:1.The greatest incidence of idiopathic intussusception is in infants aged 9-24 months. A seasonal incidence has been described, with peaks in the spring, summer, and the middle of winter. These periods correspond to peaks in the occurrence of seasonal gastroenteritis and upper respiratory tract infections.

Age. Two thirds of children with intussusception are younger than 1 year; most commonly, intussusception occurs in infants aged 5-10 months. Although extremely rare, intussusception has been reported in the neonatal period.

Intussusception can account for as many as 25% of abdominal surgical emergencies in children younger than 5 years, exceeding the incidence of appendicitis. Intussusception is the most common cause of intestinal obstruction in patients aged 5 months to 3 years.

From a clinical perspective, using a cutoff age of 3 years is helpful for dividing patients with intussusception into 2 groups. Patients aged 5 months to 3 years who have intussusception rarely have a lead point (ie, idiopathic intussusception), and they usually are responsive to nonoperative reduction. Older children and adults more often have a surgical lead point to the intussusception and require operative reduction.

Mortality/Morbidity. Most patients recover if treated within 24 hours. Mortality with treatment is 1-3%. If left untreated, this condition is uniformly fatal in 2-5 days.Recurrence is observed in 3-11% of cases. Most recurrences involve intussusceptions that were reduced with contrast enema.

Clinical manifestations

History. The constellation of signs and symptoms of intussusception represents one of the most classic presentations of any pediatric illness; however, the classic triad of vomiting, abdominal pain, and passage of blood per rectum occurs in only one third of patients. The patient is usually an infant presenting with vomiting, abdominal pain, passage of blood and mucus, lethargy, and a palpable abdominal mass. These symptoms often are preceded by an upper respiratory infection. In rare circumstances, the parents report 1 or more previous attacks of abdominal pain within 10 days to 6 months prior to the current episode. These patients are more likely to have a surgical lead point causing recurrent attacks of intussusception with spontaneous reduction. Symptoms include the following:

Pain is colicky, severe, and intermittent. The parents or caregivers describe the child as drawing the legs up to the abdomen and kicking the legs in the air.

Initially, vomiting is nonbilious and reflexive, but when the intestinal obstruction occurs, vomiting becomes bilious. Any child with bilious vomiting is assumed to have a condition that must be treated surgically until proven otherwise.

Parents also report the passage of stools that look like currant jelly. This is a mixture of mucus, sloughed mucosa, and shed blood.

Lethargy is a relatively common presenting symptom with intussusception. The reason lethargy occurs is unknown, since lethargy has not been described with other forms of intestinal obstruction. Lethargy can be the sole presenting symptom, which makes the diagnosis challenging. Patients are found to have an intestinal process late, after initiation of a septic workup.

Diarrhea also can be an early sign of intussusception.

Physical: On physical examination, the patient is usually chubby and in good health. Intussusception is uncommon in children who are malnourished. The child is found to have periods of lethargy alternating with crying spells, and this cycle repeats every 15-30 minutes. The infant can be pale, diaphoretic, and hypotensive if shock has occurred.

The hallmark physical findings in intussusception are a right hypochondrium sausage-shaped mass and emptiness in the right lower quadrant (Dance sign). This is hard to detect and is palpated best when the infant is quiet between spasms of colic.

Abdominal distention frequently is found if obstruction is complete.

If intestinal gangrene and infarction have occurred, peritonitis can be suggested on the basis of rigidity and involuntary guarding.

Early in the disease process, occult blood in the stools is the first sign of impaired mucosal blood supply. Later on, frank hematochezia and the classic currant jelly stools appear.

Fever and leukocytosis are late signs and can indicate transmural gangrene and infarction.

A rare presentation of intussusception is prolapse of the intussusceptum through the anus. This prolapse can be confused with rectal prolapse. Careful examination can differentiate between the 2 presentations. The anal crypts are everted with prolapse and not with intussusception. An examining finger can pass between the prolapse and the anus in patients with intussusception but not in patients with rectal prolapse.

Patients with intussusception often have no classic signs and symptoms, which can lead to an unfortunate delay in diagnosis and can have disastrous consequences.

Maintaining a high index of suspicion for intussusception is essential when evaluating a child younger than 5 years who presents with abdominal pain or when evaluating a child with HSP or hematologic dyscrasias.

In 1941, Ladd and Gross described the deceivingly healthy appearance of infants with intussusception.

One rarely finds intussusception in a child who is thin, undernourished, and poorly developed. On the contrary, babies with intussusception are usually very well nourished and are generally above the average in physical development. This fat and healthy appearance is apt to mislead the physician if he sees the baby in the early hours of illness. Thus, the first visit may result only in the impression that the parent is overanxious, whereas a return visit the next day shows that the child is desperately ill.

Lab Studies: perform lab studies as needed for the febrile, dehydrated, or unstable patient.

Imaging Studies:

Plain abdominal x-ray findings may be normal early in the disease or may show perforation, typical obstructive pattern, or soft tissue mass of the intussusception on the right side. A paucity of gas in the right upper quadrant may be present. On abdominal radiographs, the classical description of an intussusception is a mass lesion seen indenting the colon with or without signs of bowel obstruction. There is a paucity of right-sided colonic gas. Intussusceptions may present anywhere along the colon and even present in the rectum. The typical location is from the hepatic flexure to mid descending colon. A normal abdominal radiograph does not exclude intussusception.

Air enema showing the intussusception is in the

splenic flexure (arrow).

Ultrasonography. First reported as a useful diagnostic tool in intussusception by Burke in 1977, the utility of ultrasonography in the diagnosis of intussusception has been verified by a number of authors, with a sensitivity and specificity of 100%.

Characteristic findings include a target sign visible on transverse section and a pseudo kidney sign viewed on longitudinal section.

Sonography is best used as a diagnostic tool of exclusion when the index of suspicion for intussusception is lower. Ultrasonography is very useful in experienced hands for the diagnosis of ileoileal intussusception.

In the patient in whom a high index of suspicion for the diagnosis of intussusception exists, valuable time and money may be wasted on ultrasonography and the patient should preferably be taken directly for diagnostic and therapeutic air or hydrostatic enema.

Colour Doppler has been used to assess bowel viability and as a prognostic sign that reduction will be successful, no colour signal of the intussusception being regarded as having a poor prognosis. This finding is still under debate. One may sometimes see intestinal lymphadenopathy with intussusception.

 

Computed tomography (CT) scan also has been proposed to be useful making the diagnosis of intussusception; however, CT findings are unreliable, and use of CT carries the risks associated with intravenous contrast administration, radiation exposure, and sedation.

Small bowel intussusception. There is a central polypoid soft tissue mass (arrow) which acted as the lead point of an intussusception in the proximal ileum. Note the adjacent layer of fat corresponding to intussuscepted mesentery and the outer soft tissue layer representing the intussuscipiens. A hamartoma was found at surgery.

 

Diagnostic and therapeutic enema

Once the diagnosis of intussusception is entertained, surgical personnel should be notified and an intravenous (IV) line and nasogastric tube should be placed. The surgeon preferably is present in the radiology suite at the time of the contrast enema examination.

The presence of peritonitis and any evidence of perforation revealed on plain radiographs are the only 2 absolute contraindications to an attempt at nonoperative reduction with a therapeutic enema. Therapeutic enemas can be hydrostatic, with either barium or water-soluble contrast, or pneumatic, with air insufflation. Therapeutic enemas can be performed under fluoroscopic or ultrasonic guidance. The technique chosen is not important as long as the radiologist performing the enema is comfortable with the method. Preferably, the pediatric surgeon involved is present at the reduction.

Since the description by Hirschsprung of a systematic approach to hydrostatic reduction of intussusception, the reported success rate of this nonoperative intervention has varied widely (<40% to >90%). This variability in outcome attests to the variety of factors involved in successful hydrostatic reduction. Among these are factors that are individual to the patient (age, duration of symptoms, presence of lead points) and others that depend on the technique used. Paramount among the latter category is the availability of a team of pediatric surgeons and radiologists with the necessary expertise, determination, and dedication. Even among pediatric radiologists, consensus has been lacking on methodologic issues, including the choice of reducing agent, the type of catheter, the role of the external manipulation of the abdomen, the use of medications, and the establishment of guidelines for pressure limits and number of attempts.

When performing a therapeutic enema, the recommended pressure of air insufflation should not exceed 120 cm of water. When using barium or water-soluble contrast, the column of contrast should not exceed 100 cm above the level of the buttocks. An attempt is not considered successful until the reducing agent, whether air, barium, or water-soluble contrast, is observed refluxing back into the terminal ileum. Otherwise, the intussusception can remain at the ileocecal region and can resume its progression.

The value of repeated attempts at nonoperative reduction, if the first attempt is unsuccessful, has not been determined. Some clinicians recommend taking the patient to surgical care if the first attempt fails, while other clinicians advocate one or two subsequent attempts within a few minutes to a few hours after the first attempt. Delay between the reduction attempts may place the patient in the “window” of spontaneous resolution, which has been reported with an incidence of 5-6%. In addition, the first attempt can reduce the intussusception partially, making the intussusceptum less edematous with improved venous drainage.

Some reports have postulated that reduced edema with better venous drainage is one reason the success rate of hydrostatic reduction improves with administration of a second enema. If repeated attempts are unsuccessful, any progress in pushing back the intussusceptum toward the ileocecal valve during operative reduction is advantageous. Delay in performing surgery because of additional attempts at nonoperative reduction has been demonstrated to have no adverse effects on the rates of success of operative reduction and morbidity in the patient.

When therapeutic enema is successful, the results are immediate and extremely gratifying. The infant falls asleep almost immediately, and the obstruction is relieved, allowing the resumption of a normal diet. A short period of overnight observation usually is warranted before discharge. The recurrence rate of intussusception after nonoperative reduction is usually less than 10% but has been reported as high as 21%. Most intussusceptions recur within 72 hours of the initial event; however, recurrences have been reported up to 36 months later. More than one recurrence suggests the presence of a lead point. A recurrence usually is heralded by the onset of the same symptoms as appeared during the initial event. Provide similar treatment for a recurrence unless the suggestion of a lead point is very strong; in which case, contemplate surgical exploration.

Therapeutic enema is of no value in patients with small bowel–to–small bowel intussusception, which usually occurs in older patients who have other associated diseases (eg, HSP, hemophilia, Peutz-Jeghers syndrome, malignancies).

Treatment

Medical therapy: Expeditious diagnosis and management is essential to successful outcome in infants with intussusception. Once the diagnosis of intussusception is entertained, surgical personnel should be notified and an IV line should be inserted and IV hydration should be started. A nasogastric tube should be inserted and placed to suction. If the patient is markedly distended or has a dilated loop of bowel, an abdominal radiograph should be obtained. Antibiotics should be administered based on clinical suspicion of peritonitis or infection (sepsis) or in patients with a markedly elevated WBC count.

Preoperative details. Preoperatively, IV crystalloid resuscitation is begun (10 mL/kg x 2, plus 1.5 x maintenance fluid). A Foley catheter is placed to guide fluid resuscitation. A nasogastric tube is placed. Broad-spectrum IV antibiotics are administered. Body temperature must be preserved in the operating room. A type and screen of the patient’s blood should be obtained. As with any patient with a bowel obstruction, careful induction (ie, rapid sequence) of anesthesia should take regurgitation and risk of aspiration into consideration.

Indication for Surgery. A residual intraluminal filling defect even with terminal reflux into the ileum has to be considered as incomplete reduction. Early or multiple recurrences mean a likely leading point exists.Whenever a pathological leading point is suggested a straight-forward surgery is recommended. With evidence of a seriously ill patient with peritonitis by bacterial translocation, by perforation or by necrosis, as well as in a septic status, the treatment of choice is primarily surgical.Whenever no intussusception in the colon is found in obvious bowel obstruction by ultrasound or enema fluoroscopy, the operation should be started at once because intussusception is likely to be located in the small gut. Preparation of the patient for surgery in cases of intussusception should include decompression of gastrointestinal tract by open nasogastric tube, and monitoring of body temperature and oxygen. Laboratory studies show dehydration, electrolyte deficiencies, base excess abnormalities and inflammatory parameters. Antibiotics may be started even pre-operatively when there are signs of peritonitis or sepsis. On the operating table, the child lies on his or her back with a roll under his middle abdomen and is under general anaesthesia including full relaxation. Mostly, a right transverse incision supra-umbilical at the umbilicus or lower is recommended, adapted to the position of the apex of intussusception.A midline longitudinal incision is an easier and quicker approach and may be used as well. Pararectal incision has been abandoned. Extensions of the incisions mentioned are readily possible if required. In right transverse line the skin is cut. Fat, anterior rectus sheet, rectus muscle, posterior rectus sheet and lateral abdominal muscles, i.e., m. obliquus externus, internus and transversus, are incised, mostly using diathermy. As soon as abdominal cavity is entered, free peritoneal fluid is aspirated and a swab is taken. Cloudy or sanguineous fluid raises the suspicion that a perforation or necrosis is going to be found.

If the intussusception can be reduced easily and rapidly there is no need to deliver the intussusception. Thus, the incision may remain smaller, not bringing the whole intussusception outside the abdomen, as well as when a partial reduction could be managed intra-abdominally. But whenever the manoeuvre of reduction is difficult and an inspection of viability is necessary, it is easier to be done with the intussusception outside. In order to deliver the intussusception it may be wise to mobilize the bands of right ascending colon to lateral abdominal wall by division.Often this is not necessary because of a mobile caecum and ascending colon. Fluid contaminated by bacterial translocation may escape from the space between intussusception. Therefore, positioning of packs should avoid further contamination during reposition. Manual reduction has to be performed very carefully and slowly. Taking the apex of intussusception between fingers and cup of the surgeon’s hand at the distal end, the intussusception is squeezed gently in a retrograde direction distally to proximally. A layer of gauze between bowel and fingers may facilitate this procedure. This gentle manipulation should be more pushing at the apex rather than pulling proximally at the intussusception. Time is an important factor since oedema must be allowed to dissipate in order to avoid serosal or even seromuscular tearing. Should this happen, serosal defects are left alone, seromuscular flaps are repositioned and fixed by 5/0 stitches. Attempts to perform reduction with instruments are followed by heavy laceration due to oedema and fragility. The reduced bowel wall is always oedematous with a non-shiny serosa, but may be discoloured or even blue or black. As a test of viability, administering moist and warm wraps may serve in order to check whether there is a regular colour coming back after some minutes of waiting.

A check for a leading point is very important. It is regularly found after a full reduction that the circumference of the bowel formerly intussuscepted is thickened and oedematous and a typical dimple is recognised at the site of the former leading point. This dimple, a Payer’s patch or an oedematous ileocecal valve can mimic an intraluminal pathological mass as lead point, but careful palpation and the knowledge of this likely condition of dimple formation should prevent excising local tissue as a probe or even an unnecessary resection, particularly in the typical infant age group. Appendectomy is usually perfomed. Additional fixation of terminal ileum is hardly mentioned in the literature. To preventing a second intussusception, it does make sense to fix that part where the disease is starting most often, i.e., the terminal ileum. Three sero– serosal stitches, 5/0 or 4/0, from terminal ileum to ascending colon are performed quickly and not interfering with mesenteric vessels. Since the rate of recurrence is not high, it remains a personal decision regarding whether to do a fixation at initial intussusception. In recurrent intussusception it is of definite benefit, since the ileocecal valve is widened. For closure the abdominal cavity is irrigated with warm saline. No drainage is used. The peritoneum and posterior rectus sheet is closed at the same time by running 3/0 sutures. Continuous suturing is also sufficient for anterior rectus sheet.A subcuticular 4/0 running suture provides a good skin adaptation and a cosmetically good scar. Skin closure by intracuticular suture line, by fibrin sealant or metal clips is optional. Indications for resection include irreducible intussusception, gangrenous bowel or perforation of the bowel. After resection of the bowel, end-to-end intestinal anastomosis is completed

Postoperative details. IV fluid resuscitation is continued and calculated, taking into consideration maintenance requirements and third-space losses. Upon resolution of ileus, diet is advanced at the discretion of the surgeon.

Follow-up care. In older children or in cases of recurrent intussusception (after 3-4 episodes) successfully reduced with an enema, evaluating the patient for a lead point (eg, upper gastrointestinal series, Meckel scan) should be considered.

Intussusception results in bowel obstruction; thus, complications such as dehydration and aspiration from emesis can occur. Ischemia and bowel necrosis can cause bowel perforation and sepsis. Necrosis of a significant length of intestine can lead to complications associated with short bowel syndrome. Whether treated by operative or radiographic reduction, late stricture (4-8 weeks) may occur within the length of intestine involved.

The overall mortality rate of intussusception is less than 1%. Recurrence rates following nonoperative reduction are approximately 5% and 1-4% following surgical reduction.

The following criteria are associated with a higher failure rate of nonoperative reduction:

–         Ileoileocolic intussusception

–         Long duration of symptoms

–         Rectal bleeding

–         Failed reduction with barium at another institution

–         Age older than 2 years or younger than 3 months

–         Duration of symptoms longer than 24 hours

–         Small-bowel obstruction on radiograph

–         Dehydration of greater than 5%

–         Inexperienced radiologist

Factors significantly predictive of bowel perforation are younger age and a longer duration of symptoms. The risk of postoperative adhesive small-bowel obstruction following nonoperative reduction is 0%; for operative reduction, it has been reported in as many as 5% of patients.

1.3. Dynamic intestinal obstruction

 

Acute Paralytic Ileus

 Essentials of Diagnosis

■ Precipitating factors: surgery, peritonitis, electrolyte abnormalities, medications, severe medical illness.

■ Nausea, vomiting, obstipation, distention.

■ Minimal abdominal tenderness; decreased bowel sounds.

■ Plain abdominal radiography with gas and fluid distention in small and large bowel. General Considerations

Ileus is a condition in which there is neurogenic failure or loss of peristalsis in the intestine in the absence of any mechanical obstruction. It is commonly seen in hospitalized patients as a result of: (1) intra-abdominal processes such as recent gastrointestinal or abdominal surgery or peritoneal irritation (peritonitis, pancreatitis, ruptured viscus, hemorrhage); (2) severe medical illness such as pneumonia, respiratoryfailure requiring intubation, sepsis or severe infections, uremia, diabetic ketoacidosis, and electrolyte abnormalities (hypokalemia, hypercalcemia, hypomagnesemia, hypophosphatemia); and (3) medications that affect intestinal motility (opioids, anticholinergics, phenothiazines). Following surgery, small intestinal motility usually normalizes first (often within hours), followed by the stomach (24-48 hours), and the colon (48-72 hours).

Clinical Findings

SYMPTOMS AND SIGNS

Patients who are conscious report mild diffuse, continuous abdominal discomfort with nausea and vomiting. Generalized abdominal distention is present with minimal abdominal tenderness but no signs of peritoneal irritation (unless due to the primary disease). Bowel sounds are diminished to absent.

LABORATORY FINDINGS

The laboratory abnormalities are attributable to the underlying condition. Serum electrolytes, including potassium, magnesium, phosphorus, and calcium, should be obtained to exclude abnormalities as contributing factors.

IMAGING

Plain film radiography of the abdomen demonstrates distended gas-filled loops of small and large intestine. Air-fluid levels may be seen. Under some circumstances, it may be difficult to distinguish ileus from partial small bowel obstruction. A limited barium small bowel series or a CTscan maybe useful in such instances to exclude mechanical obstruction, especially in postoperative patients.

Differential Diagnosis

Ileus must be distinguished from mechanical obstruction of the small bowel or proximal colon. Pain from small bowel mechanical obstruction is usually intermittent, cramping, and associated initially with profuse vomiting. Acute gastroenteritis, acute appendicitis, and acute pancreatitis may all present with ileus.

Treatment

The primary medical or surgical illness that has precipitated adynamic ileus should be treated. Most cases of ileus respond to restriction of oral intake with gradual liberalization of diet as bowel function returns. Severe or prolonged ileus requires nasogastric suction and parenteral administration of fluids and electrolytes. Alvimopan is a new peripherally acting mu-opioid receptor antagonist with limited absorption or systemic activity that reverses opioid- induced inhibition of intestinal motility. This agent is not yet approved by the FDA. However, in five randomized controlled trials, it reduced the time to first flatus, bowel movement, solid meal, and hospital discharge compared with placebo in postoperative patients.

Tan EKet al. Meta-analysis: alvimopan vs. placebo in the treatment of post-operative ileus. Aliment Pharmacol Ther. 2007 Jan 1;25(1):47-57. [PMID: 17042776]

 

Acute Colonic Pseudo-Obstruction (Ogilvie Syndrome)

Essentials of Diagnosis

■ Severe abdominal distention.

■ Arises in postoperative state or with severe medical illness.

■ May be precipitated by electrolyte imbalances, medications.

■ Absentto mild abdominal pain; minimal tenderness.

■ Massive dilation of cecum or right colon. General Considerations

Spontaneous massive dilation of the cecum and proximal colon may occur in a number of different settings in hospitalized patients. Progressive cecal dilation may lead to spontaneous perforation with dire consequences (see x-ray). The risk of perforation correlates poorly with absolute cecal size and duration of colonic distention. Early detection and management are importantto reduce morbidity and mortality. Colonic pseudo-obstruction is most commonly detected in postsurgical patients (mean 3-5 days), aftertrauma and in medical patients with respiratoryfailure, metabolic imbalance, malignancy, myocardial infarction, congestive heart failure, pancreatitis, or a recent neurologic event (stroke, subarachnoid hemorrhage, trauma). Liberal use of opioids or anticholinergic agents may precipitate colonic pseudo-obstruction in susceptible patients. It may also occur as a manifestation of colonic ischemia. The etiology of colonic pseudo-obstruction is unknown, but either an increase in gut sympathetic activity or a decrease in sacral parasympathetic activity of the distal colon, or both, is hypothesized to impair colonic motility.

 

Clinical Findings

SYMPTOMS AND SIGNS

Many patients are on ventilatory support or are unable to report symptoms due to altered mental status. Abdominal distention is frequently noted by the clinician as the first sign, often leading to a plain film radiograph that demonstrates colonic dilation. Some patients are asymptomatic, although most report constant but mild abdominal pain. Nausea and vomiting may be present. Bowel movements may be absent, but up to 40% of patients continue to pass flatus or stool. Abdominal tenderness with some degree of guarding or rebound tenderness may be detected; however, signs of peritonitis are absent unless perforation has occurred. Bowel sounds may be normal or decreased.

LABORATORY FINDINGS

Laboratory findings reflect the underlying medical or surgical problems. Serum sodium, potassium, magnesium, phosphorus, and calcium should be obtained. Significant fever or leukocytosis raises concern for colonic ischemia or perforation.

IMAGING

Radiographs demonstrate colonic dilation, usually confined to the cecum and proximal colon (see x-ray). The upper limits of normal for cecal size is 9 cm. A cecal diameter greater than 10-12 cm is associated with an increased risk of colonic perforation. Varying amounts of small intestinal dilation and air-fluid levels due to adynamic ileus maybe seen. Because the dilated appearance of the colon may raise concern that there is a distal colonic mechanical obstruction due to malignancy, volvulus, or fecal impaction, a CTscan or water-soluble (diatrizoate meglumine) enema may sometimes be performed.

Postoperative ileus. Gaseous dilation of small and large bowel is present with significant cecal distention. Spontaneous resolution occurred. (Reproduced, with permission, from Bongard FS, Sue DY [editors]: Current Critical Care Diagnosis & Treatment. Originally published by Appleton S Lange. Copyright© 1994 by The McGraw-Hill Companies, Inc.)

 

Differential Diagnosis

Colonic pseudo-obstruction should be distinguished from distal colonic mechanical obstruction (as above) and toxic megacolon, which is acute dilation of the colon due to inflammation (inflammatory bowel disease) or infection (C d/ffia/e-associated colitis, CMV). Patients with toxic megacolon manifest fever; dehydration; significant abdominal pain; leukocytosis; and diarrhea, which is often bloody.

Treatment

Conservative treatment is the appropriate first step for patients with no or minimal abdominal tenderness, no fever, no leukocytosis, and a cecal diameter less than 12 cm. The underlying illness is treated appropriately. A nasogastric tube and a rectal tube should be placed. Patients should be ambulated or periodically rolled from side to side and to the knee-chest position in an effort to promote expulsion of colonic gas. All drugs that reduce intestinal motility, such as opioids, anticholinergics, and calcium channel blockers, are discontinued if possible. Enemas maybe administered judiciously if large amounts of stool are evident on radiography. Oral laxatives are not helpful and may cause perforation, pain, or electrolyte abnormalities.

Conservative treatment is successful in over 80% of cases within 1-2 days. Patients must be watched for signs of worsening distention or abdominal tenderness. Cecal size should be assessed by abdominal radiographs every 12 hours. Intervention should be considered in patients with any of the following: (1) no improvement or clinical deterioration after 24-48 hours of conservative therapy; (2) cecal dilation > 10 cm for a prolonged period (> 3-4 days); (3) patients with cecal dilation > 12 cm. Neostigmine injection should be given unless contraindicated. A single dose (2 mg intravenously) results in rapid (within 30 minutes) colonic decompression in 75-90% of patients. Cardiac monitoring during neostigmine infusion is indicated for possible bradycardia that may require atropine administration. Colonoscopic decompression is indicated in patients who fail to respond to neostigmine. Colonic decompression with aspiration of air or placement of a decompression tube is successful in 70% of patients. However, the procedure is technically difficult in an unprepared bowel and has been associated with perforations in the distended colon. Dilation recurs in up to 50% of patients. In patients in whom colonoscopy is unsuccessful, a tube cecostomy can be created through a small laparotomy or with percutaneous radiologically guided placement.

Prognosis

In most cases, the prognosis is related to the underlying illness. The risk of perforation or ischemia is increased with cecal diameter > 12 cm and when distention has been present for more than 6 days. With aggressive therapy, the development of perforation is unusual.

Saunders MD. Acute colonic pseudo-obstruction. Gastrointest Endosc Clin N Am. 2007 Apr;17(2):341-60. [PMID: 17556152]

Chronic Intestinal Pseudo-Obstruction & Gastroparesis

Gastroparesis and chronic intestinal pseudo-obstruction are chronic conditions characterized by intermittent, waxing and waning symptoms and signs of gastric or intestinal obstruction in the absence of any mechanical lesions to account for the findings. They are caused bya heterogeneous group of endocrine disorders (diabetes mellitus, hypothyroidism, Cortisol deficiency), postsurgical conditions (vagotomy, partial gastric resection, fundoplication, gastric bypass, Whipple procedure), neurologic conditions (Parkinson disease, muscular and myotonic dystrophy, autonomic dysfunction, multiple sclerosis, postpolio syndrome, porphyria), rheumatologic syndromes (progressive systemic sclerosis), infections (postviral, Chagas disease), amyloidosis, paraneoplastic syndromes, medications, and eating disorders (anorexia); a cause may not always be identified.

Gastric involvement leads to chronic or intermittent symptoms of gastroparesis with postprandial fullness (early satiety), nausea, and vomiting (1-3 hours after meals). Patients with predominantly small bowel involvement may have abdominal distention, vomiting, diarrhea, and varying degrees of malnutrition. Abdominal pain is not common and should prompt investigation for structural causes of obstruction. Bacterial overgrowth in the stagnant intestine may result in malabsorption. Colonic involvement may result in constipation or alternating diarrhea and constipation.

Plain film radiography may demonstrate dilation of the esophagus, stomach, small intestine, or colon resembling ileus or mechanical obstruction. Mechanical obstruction of the stomach, small intestine, or colon is much more common than gastroparesis or intestinal pseudo-obstruction and must be excluded with endoscopy, barium radiography (upper gastrointestinal series with small bowel follow-through), or CT enterography, especially in patients with prior surgery, recent onset of symptoms, or abdominal pain. In cases of unclear origin, studies based on the clinical picture are obtained to exclude underlying systemic disease. Gastric scintigraphy with a low-fat solid meal is the optimal means for assessing gastric emptying. Gastric retention of 60% after 2 hours or more than 10% after 4 hours is abnormal. Small bowel manometry is useful for distinguishing visceral from myopathic disorders and for excluding cases of mechanical obstruction that are otherwise difficult to diagnose by endoscopy or radiographic studies.

There is no specific therapy for gastroparesis or pseudo-obstruction. Acute exacerbations are treated with nasogastric suction and intravenous fluids. Long-term treatment is directed at maintaining nutrition. Patients should eat small, frequent meals that are low in fiber, milk, gas-forming foods, and fat. Some patients may require liquid enteral supplements. Agents that reduce gastrointestinal motility (opioids, anticholinergics, calcium channel blockers) should be avoided. In diabetics, glucose levels should be maintained below 200 mg/dL, as hyperglycemia may slow gastric emptying even in the absence of diabetic neuropathy, and amyline analogs (exenatide or pramlintide) should be discontinued. Metoclopramide (5-20 mg orally or 5-10 mg intravenously or subcutaneouslyfourtimes daily) and erythromycin (50-125 mg orally three times daily) before meals are of benefit in treatment of gastroparesis but not small bowel dysmotility. The 5-HT₄-receptor agonist tegaserod has been withdrawn by the FDA, so is no longer available in the

United States for this indication. Unblinded studies in small numbers of patients with diabetic or idiopathic gastroparesis report improvement in symptoms and gastric emptying after injection of botulinum toxin into the pylorus, which is hypothesized to reduce pyloric spasm; however, a controlled trial showed no efficacy. Gastric electrical stimulation with internally implanted neurostimulators has shown reduction in vomiting in small studies of patients with severe gastroparesis; however, no randomized studies have been conducted and the mechanism of action is uncertain. Bacterial overgrowth should be treated with intermittent antibiotics (see above). Patients with predominant small bowel distention may require a venting gastrostomy to relieve distress. Some patients may require placement of a jejunostomy for long-term enteral nutrition. Patients unable to maintain adequate enteral nutrition require TPN or small bowel transplantation. Difficult cases should be referred to centers with expertise in this area.

 

2. Digestive tract bleeding in children.

 

2.1. Peptic ulcer Disease,

The lesion of peptic ulcer disease (PUD) is a disruption in the mucosal layer of the stomach or duodenum. An ulcer is distinguished from erosion by its penetration of the muscularis mucosa or the muscular coating of the gastric or duodenal wall.

A peptic ulcer can be classified as either primary (ie, associated with H pylori infection) or secondary, with a variety of factors, including excess acid production, stress, use of medications, and the presence of other underlying conditions. Primary peptic ulcers characteristically occur in children older than 10 years, most commonly occur in the duodenum, are associated with H pylori gastritis, and may result in chronic or recurrent symptoms. Genetic factors may be important as indicated by the observation that as many as 50% of children with PUD have a first- or second-degree relative with PUD. Secondary ulcers are usually gastric in location and occur more commonly in infants and young children. Patients with secondary ulcers often present with acute disease. Secondary ulcers have the potential for higher morbidity and mortality rates; however, once patients with secondary ulcers are treated successfully, little risk of recurrence exists.

Pathophysiology. PUD represents the imbalance between defensive factors that protect the mucosa and offensive or aggressive factors that disrupt this important barrier. Protection is afforded to the gastric mucosa by the cytoprotective barrier of water-insoluble mucous that overlies epithelial cells, gastric- and pancreaticobiliary-produced bicarbonate, an unstirred water layer, phospholipids, rapidly replaced cells resulting from epidermal growth factor, mucosal blood flow, and prostaglandins that serve to increase bicarbonate and mucous production and inhibit acid secretion. Aggressive factors to mucosal inflammation and ulceration include gastric acidity, acid-dependent pepsin, mucosal ischemia, drugs (nonsteroidal anti-inflammatory drugs [NSAIDs], aspirin, corticosteroids), alcohol, cigarette smoking, exposure to corrosive chemicals (eg, lye), and emotional stress. Serious systemic illness, sepsis, hypotension, respiratory failure, and multiple traumatic injuries increase the risk for secondary (stress) ulceration. In these patients mucosal ischemia increased production of gastric acid and pepsin, higher levels of endogenous catecholamines and steroids, and decreased production of prostaglandins and mucous. Important mediators of mucosal inflammation and resultant ulceration include oxygen free radicals, lymphokines, and monokines.

The ulcer associated with a brain tumor or injury (Cushing ulcer) is characterized as single, deep, and prone to perforation; associated with high gastric acid output; and located in the duodenum or stomach. Extensive burns are associated with ulcer formation as well (ie, Curling ulcer).

Clinical and laboratory studies provide strong evidence that H pylori infection causes chronic gastritis, which has a strong correlation with primary duodenal ulcer disease. The microbiologic characteristics of this organism, which afford it important protection in the hostile acidic environment of the stomach, allow the organism to safely inhabit its host for years, producing mucosal inflammation and, in some, more severe disease.

When gastric mucosa is colonized with H pylori, inflammation usually results. The association between H pylori gastritis and duodenal ulceration is well described. No strong association exists between H pylori gastritis and gastric ulceration in children.

Frequency. PUD is an uncommon disease of childhood, with an estimated frequency of 1 case in 2500 hospital admissions. The estimated prevalence of childhood PUD in large general pediatric practices is 1.7%. The true incidence of secondary ulcers is unknown and depends on the frequency of systemic illness, traumatic injury, other chronic diseases, and injurious drug use.

Age. Primary PUD is rare in infants and children younger than 10 years. Prevalence of primary PUD increases during adolescence. Secondary PUD can be found in patients of all ages but has a higher prevalence in patients younger than 6 years.

Sex. Primary PUD has a 2- to 3-fold higher incidence in boys than in girls; however, no sex difference in incidence rates in primary PUD has beeoted in infants or very young children.

Clinical manifestation.

In children in whom PUD is suspected, include the following in the history:

Review of past illnesses and chronic medical conditions

Family history of ulcer disease or GI tract conditions (eg, Crohn disease)

Character, location, frequency, duration, severity, and exacerbating (especially meals in children) and alleviating factors of abdominal pain

Vomiting and description of gastric material

Bowel habits and description of stool

Medications

Prior diagnostic testing and specific GI therapies

Appetite, diet, and weight changes

Family and social stressors

Alcohol ingestion and smoking habits

Abdominal pain is the most common symptom of childhood PUD. The pain is usually dull and vague in character and may be poorly localized or localized to the periumbilical or epigastric areas. In preschool-aged children, pain is typically periumbilical and is worse after eating. After age 6 years, the child’s description of pain may be quite similar to the description made by adults. The classic pain of PUD (ie, pain that awakens the child, worsens with food, and is relieved by fasting) is described infrequently, but it helps distinguish GI tract and psychogenic pathology when present. Pain is more likely to be dull and aching rather than sharp and burning, as is described by adults. Frequent exacerbations and remissions of pain extend over weeks to months. The pain is often worsened by food intake, which is the opposite of the adult pattern.

Vomiting in infants and toddlers may be associated with slow growth. Recurrent vomiting is also noted in preschool-aged and school-aged children.

GI tract bleeding (eg, melena, hematochezia, hematemesis) may be another presentation in children; however, in infants, particularly in the first month of life, serious underlying illness and stress ulceration present most commonly with acute perforation or hemorrhage.

Lab Studies.

Hemoglobin and hematocrit

To diagnose anemia in the setting of chronic GI tract blood loss

To determine the severity of anemia in the setting of acute or massive GI tract bleeding

To guide and monitor transfusion or iron therapy

Iron studies (serum iron, total iron-binding capacity [TIBC], ferritin, reticulocyte count, peripheral smear) – to determine presence of IDA.

H pylori serology – to detect H pylori infection in children who have not been previously diagnosed or treated.

Prothrombin time (PT) and activated partial thromboplastin time (aPTT) – to identify coagulopathy in patients with sepsis, multiple injuries, or massive GI tract bleeding, or in those at risk for diffuse intravascular coagulation (DIC).

Type and cross-match blood – for transfusion in patients in whom the condition is unstable or the illness is critical.

Electrolyte and creatinine levels – for assessment in patients with volume depletion or who require fluid resuscitation.

Arterial blood gas – to assess degree of acidosis in the patient with systemic illness, respiratory failure, or severe hypovolemia or in patients with severe burns or trauma.

Urinalysis – to assess hydration status and to screen for infection or stone.

WBC count and differential – to detect peripheral eosinophilia in children with eosinophilic gastritis.

Serum gastrin and gastrin-releasing peptide levels – to exclude Zollinger-Ellison syndrome in patients with refractory ulcers.

Examine and perform guaiac testing on the stool to confirm GI tract bleeding. Melena is usually the result of an upper GI tract bleed, although blood from a duodenal ulcer that quickly transits the intestinal tract may be visible as red or maroon blood in the stool.

Imaging Studies. 

Abdominal and/or chest radiograph findings assist in the diagnosis of perforation.

Upper GI series can depict PUD in approximately 70% of children who are studied. A double-contrast study has a higher detection rate but requires an older cooperative child and results in higher radiation exposure.

 

Figure  Barium meal – duodenal ulcer. Double-contrast barium meal. Duodonal ulcer (arrow) seen as a crater filled with barium. Note mucosal folds radiating from the ulcer.

 

The false-positive rate may be 30%. Sensitivity is higher for detection of duodenal ulcers than for detection of gastric ulcers. Radiologic findings of duodenal ulcers include filling defects or duodenal bulb deformities.

The presence of a fibrinous clot in the ulcer may lead to false-negative findings. False-positive findings on barium studies have beeoted as especially high in the pediatric patient population, up to 30-40%.

Gastric outlet obstruction, the result of pyloric lesions, can be detected using upper gastrointestinal imaging (UGI).

Procedures.

Consider nasogastric (NG) lavage in a child who is ill and in whom an upper GI tract hemorrhage is suspected, as evidenced by hematemesis or melena.

Esophagogastroduodenoscopy (EGD) is the procedure of choice for the detection of PUD in the pediatric population. EGD allows direct visualization of the mucosa, localization of the source of bleeding, and diagnosis of H pylori infection via analysis of biopsy specimens, culturing, or detection of urease activity.

Therapeutic endoscopy for acute bleeding (coagulation of a bleeding ulcer with a heater probe or injection with vasoconstricting agents) is another important indication for EGD.

 

Peptic Ulcer Disease

 

Blood spurting from a small ulcer.

 

Histologic Findings. Histologic analysis of an active ulcer reveals 4 zones. The 4 zones, described from superficial to deep, are:

a thin layer of necrotic fibrinoid material at the base and margins of the ulcer,

a region of mostly polymorphonuclear neutrophil leukocytes (PMLs),

active granulation tissue with mononuclear leukocytes, and

a solid fibrous or collagenous scar.

Ulcers extend through mucosa and penetrate the muscularis mucosa layer into the submucosa or deeper. Antral mucosal nodularity and lymphocytic inflammation may be found in association with H pylori gastritis.

Secondary gastritis, namely, acute inflammation associated with serious underlying illness or injury, results in a predominance of PMLs. With the mucosal damage caused by corrosive agents, histologic examination reveals edema, submucosal hemorrhage, and a mild inflammatory cell infiltrate.

Complications.

Hemorrhage accompanies PUD in 15-20% of patients. An acute abdomen resulting from GI tract perforation occurs in 5-10% of children with PUD.

GI tract bleeding may lead to iron deficiency anemia (IDA) and may present with more vague complaints of fatigue, headache, dyspnea, or malaise.

The highest mortality rates are found in young infants with stress ulcers who may present acutely with life-threatening GI tract hemorrhage or intestinal perforation. In contrast, children with primary gastritis or duodenal ulcer disease have very low mortality rates.

GI tract bleeding is one of the most common presentations of ulcer disease ieonates. GI tract hemorrhage occurs in both primary and secondary PUD. GI tract blood loss may be acute and catastrophic, particularly ieonates or in children with a critical medical illness or traumatic injuries, or blood loss may take a slow and chronic course, without serious threat to life.

Perforation of an ulcer is the second main manifestation of PUD ieonates; however, any child who is critically ill or injured is at risk for stress ulceration and perforation. Perforation is often preceded by or associated with GI tract hemorrhage. For children with ulcer perforation, the symptoms are consistent with peritonitis and are abrupt in onset.

Fig.. Pneumoperitoneum. Free air on supine radiograph (arrows) seen as abnormal lucency in the right upper quadrant.

 

Fig.  Pneumoperitoneum. Massive pneumoperitoneum on supine radiograph. Free falciform ligament (arrowhead) and is seen on both sides of the bowel wall (arrow).

 

 

Obstruction of the gastric outflow tract because of edema or scarring most often occurs in the setting of duodenal or pyloric channel ulcers.

Treatment.

In children who appear to be well in whom examination findings are normal and symptoms are mild, evaluation may be conducted on an outpatient basis. Aggressive supportive care and treatment of the underlying condition is most important in children who are critically ill who have secondary ulceration complications.

In children who are ill and who have severe symptoms or serious underlying disease, inpatient stabilization, workup, and treatment may be necessary and include the following:

Assess airway, breathing, and circulation (ABC).

Administer oxygen and provide ventilatory support as appropriate.

Establish IV access, place cardiorespiratory monitors, begin volume replacement, and prepare transfusions in children who are unstable and bleeding.

Place an NG tube and perform lavage in the stomach of children in whom an upper GI tract bleed is suspected.

Consider IV infusion of a histamine H2-receptor antagonist.

Surgical intervention is required in a small percentage of infants and children with complications of PUD that include perforation, obstruction, intractable pain, and bleeding unresponsive to medical or endoscopic therapy.

A bleeding ulcer can be treated with a simple plication or oversewing of the bleeding source. A more definitive procedure may be required, such as vagotomy and pyloroplasty.

Closure of Perforation

 

In patients with stress ulcers related to brain injury or burns, the procedure of choice may be a pyloroplasty and antrectomy.

Total gastrectomy for multiple gastric ulcers is rarely performed in pediatric patients.

For perforation, repair is performed via simple closure or pyloroplasty.

Gastric outlet obstruction is relieved surgically with vagotomy and pyloroplasty or gastroenterostomy.

Various types of operations currently popular for treating duodenal ulcer disease. Total gastrectomy is reserved for Zollinger-Ellison syndrome.

 

Medications used in patients with PUD reduce gastric acidity and serve to eradicate H pylori infection.

Histamine H2-receptor antagonists. Receptors for histamine are located on the acid-producing parietal cells. Blocking histamine action suppresses gastric acid secretion.

Proton pump inhibitor (Omeprazole, Prilosec) are a much more potent acid inhibitor than H2-receptor antagonists, this class of drugs blocks gastric acid secretion at the proton pump (ie, hydrogen/potassium adenosine triphosphatase [H+/K+- ATPase] of the gastric parietal cell), which is the final common pathway of secretion. Recommended as a part of the drug regimen for symptomatic H pylori infection. Proton pump inhibition alone does not eradicate H pylori infection, but it does have bacteriostatic activity against H pylori. Pediatric dose of Omeprazole: 0.6-0.7 mg/kg/d PO initially, may increase to 0.6-0.7 mg/kg/dose PO bid; reported effective dose range is 0.7-3.3 mg/kg/d.

Antacids (Aluminum and magnesium hydroxide (Mylanta, Maalox)). Neutralize gastric acid and may be of benefit in children with PUD. Medication compliance may be a problem because of the requirement for frequent dosing.

Antibiotics. In the eradication of H pylori infection, multidrug regimens have been studied. All regimens contain 1-2 antimicrobials and agents that neutralize acid or have inhibitory effects on acid secretion.

Clarithromycin (Biaxin) – macrolide antibiotic with a antimicrobial spectrum similar to erythromycin but is more stable in an acid environment and has fewer adverse GI tract effects. Pediatric Dose: 7.5 mg/kg PO bid for 2 wk (with omeprazole and metronidazole or with omeprazole only) or for 10 d (with amoxicillin and omeprazole).

Diet. Recommend abstinence from all caffeine and alcohol. In hospitalized children, milk feedings have been found to raise the gastric pH level and to prevent GI tract bleeding.

Activity. Allow common sense to dictate appropriate activity restrictions in children with chronic symptoms.

Further Outpatient Care.

Carefully monitor medication doses, adverse effects of medications, and relief or persistence of symptoms.

Prescribe edications include blockers of gastric acid secretion, acid neutralizers, and antibiotics.

Avoid all irritative medications, including NSAIDs, aspirin, and corticosteroid preparations.

IDA may require iron replacement therapy.

Prognosis.

Mortality rates are very low in older children with primary ulceration and H pylori infection.

Mortality rates remain highest ieonates, as well as infants and children with systemic illness or injury, who present with acute bleeding or perforation.

 

2.2. Meckel’s diverticulum bleeding

 

 

Meckel diverticulum is the most common form of congenital abnormality of the small intestine, resulting from an incomplete obliteration of the vitelline duct (ie, omphalomesenteric duct, yolk stalk). Although originally described by Fabricius Hildanus in 1598, it is named after Johann Friedrich Meckel (1781–1833, German comparative anatomist and embryologist), who established its embryonic origin between 1808 and 1820.

Despite the availability of modern imaging techniques, the diagnosis of Meckel diverticulum is challenging.

Embryology, pathophysiology. Early in embryonic life, the vitelline duct connects the midgut to the yolk sac. Later on, the duct undergoes progressive narrowing and usually disappears by the seventh gestational week. When the duct fails to obliterate, different types of vitelline duct anomalies appear. Examples of such anomalies include (1) a persistent vitelline duct (appearing as a draining fistula at the umbilicus), (2) a fibrous band connecting the ileum to the inner surface of the umbilicus, (3) a patent vitelline sinus beneath the umbilicus, (4) an obliterated bowel portion, and (5) a vitelline duct cyst.

Meckel diverticulum has been reported in 97% of the vitelline duct anomalies. The tip of the diverticulum can be free in 75% of cases and attached to the anterior abdominal wall or another structure in the remainder.

Enterocystomas, umbilical sinuses, and omphaloileal fistulas are among the other congenital anomalies seen with Meckel diverticulum.

The diverticulum is supplied by the right vitelline artery. Usually the artery terminates in the diverticulum, but sometimes it has been seen continuing up to the abdominal wall. Rarely, these blood vessels persist in the form of fibrous remnants that run between the Meckel diverticulum and the abdominal wall or small-bowel mesentery.

Meckel diverticulum occurs on the antimesenteric border of the ileum, usually 60 cm proximal to the ileocecal valve. On average, the diverticulum is 2.99 cm long and 1.92 cm wide. Meckel diverticulum is a true diverticulum because it contains all layers of the intestinal wall.

The heterotopic mucosa is likely to be gastric in origin in 80% of cases of Meckel diverticulum. This is important because peptic ulceration of this or adjacent mucosa can lead to pain, bleeding, and/or perforation.

Although jejunal, colonic, rectal, pancreatic, duodenal, and endometrial tissues have all been found in the diverticulum, heterotopic gastric mucosa is the most common tissue observed.

Frequency. In the literature, incidence of Meckel diverticulum is usually quoted as approximately 2% of the population, but prevalence can vary from 0.2-4%.

Sex. Although no sex-based difference was found in studies that evaluated this condition as an incidental finding during operations, males are more prone to complications than females.

Age. Presentation in infants younger than 2 years has been considered the classic case. However, in one study, only 45% of infants were younger than 2 years.

Clinical manifestations.

History. Most patients are asymptomatic; Meckel diverticulum is usually an incidental finding when a barium study or laparotomy is performed for other abdominal conditions.

When patients develop symptoms, presence of complications is almost always indicated. Development of complications is usually rare but can occur in up to 4% of patients. Complications of Meckel diverticulum included bowel obstruction (35%), hemorrhage (32%), diverticulitis (22%), umbilical fistula (10%), and other umbilical lesions (1%).

In children, bleeding is the most common presenting sign. Most children younger than 5 years present with acute lower GI bleeding due to hemorrhage from peptic ulceration. Such ulceration is a complication of heterotopic gastric mucosa, and this hemorrhage is usually seen in the form of painless rectal bleeding. However, some patients may present only with pain preceding the onset of hematochezia; this clinical presentation can often obscure the diagnosis. Not all patients have abdominal pain, but, when present, it can be significant.

Although intestinal obstruction is not considered a major presenting clinical sign, it occurs in 25-40% of pediatric patients. Obstruction can occur as a result of various mechanisms:

Ø  Omphalomesenteric band (most frequent cause)

Ø  Internal hernia through vitelline duct remnants

Ø  Volvulus occurring around vitelline duct remnants

Ø  T-shaped prolapse of both efferent and afferent loops of intestine through a persistent vitelline duct fistula at the umbilicus in a neonate

Intussusception is another serious and common complication of the Meckel diverticulum. The diverticulum may itself act as a lead point for an ileocolic or ileoileal intussusception. None of the clinical features are pathognomonic, and the diagnosis is rarely made preoperatively.

Like other diverticula in the body, the Meckel diverticulum can become inflamed. Diverticulitis usually is seen in older patients. Meckel diverticulum is less prone to inflammation than the appendix because most diverticula have a wide mouth, have very little lymphoid tissue, and are self-emptying.

The clinical presentation includes abdominal pain in the periumbilical area that radiates to the right lower quadrant. Abdominal pain is present more in the periumbilical region than the pain of appendicitis.

Meckel diverticulitis may be disguised as appendicitis; the correct diagnosis is usually established at the laparotomy. History of bleeding per rectum may be helpful in distinguishing this entity from appendicitis.

Chronic inflammation of Meckel diverticulum is rare, but a few cases of tuberculosis and Crohn disease have been reported in the literature.

Rarely, Meckel diverticulum has been reported to become incarcerated in the inguinal, femoral, or obturator hernial sacs. Entrapment of Meckel diverticulum in an inguinal hernia is called a Littre hernia.

Even more rarely, the Meckel diverticulum may develop benign tumors (eg, leiomyomas, angiomas, neuromas, lipomas) or malignant neoplasms (eg, sarcoma, carcinoid tumor, adenocarcinomas), or it may be perforated with a swallowed fish bone or sewing needle.

Physical. Patients can present with a variety of clinical signs ranging from no symptoms to acute abdominal pain. The 3 most common presentations are gastrointestinal bleeding, intestinal obstruction, and inflammation of the diverticulum.

Gastrointestinal bleeding. Most of the time, bleeding occurs suddenly and tends to be massive in younger patients. Bleeding occurs without prior warning and usually subsides spontaneously. When a severe bleeding episode occurs, the patient can present in hemorrhagic shock. Tachycardia is the earliest clinical sign of early hemorrhagic shock.

The color of the stool often provides physicians with a clue to determine the site of bleeding. This has been well addressed in a classic description of the types of rectal bleeding associated with Meckel diverticulum. Incidence of different types of bleeding has been described as follows: dark red, ie. maroon (40%); bright red (35%); bright red or dark red (12%); dark red or tarry (6%); and tarry (7%).

When bleeding is rapid, stools are bright red or have an appearance like currant jelly; when slow bleeding occurs, the stools are black and tarry.

Intestinal obstruction. Most patients with intestinal obstruction present with abdominal pain and vomiting and have abdominal tenderness, distension, and hyperactive bowel sounds on examination. Patients may sometimes develop a palpable abdominal mass. Occasionally, when patients do not present early, or if the diagnosis is missed, the obstruction can progress to intestinal ischemia or infarction, the latter manifesting with acute peritoneal signs and lower GI bleeding.

Diverticulitis. Patients with diverticulitis present with either focal or diffuse abdominal tenderness. Usually, abdominal tenderness is more marked in the periumbilical region than the pain of appendicitis. Children may present with abdominal guarding and rebound tenderness, in addition to abdominal tenderness. Abdominal distention and hypoactive bowel sounds are late findings.

Diagnosis.

Lab Studies. Routine laboratory studies, such as CBC, electrolyte tests, glucose test, creatinine test, and coagulation screen, are not helpful in establishing the diagnosis but are helpful in the general workup. Hemoglobin and hematocrit are low in the setting of anemia or bleeding. Patients with significant bleeding can develop anemia.

Imaging Studies. History and physical examination are of paramount importance for establishing a clinical diagnosis. Imaging studies are performed to confirm a clinical suspicion of Meckel diverticulum.

Plain radiographs of the abdomen may depict signs of intestinal obstruction or perforation.

When a patient presents with bleeding and with suspicion of Meckel diverticulum, the diagnostic evaluation should include a technetium Tc 99m–pertechnetate scintiscan, or so-called Meckel scan. Scintiscan is especially helpful in infants who present with lower GI bleeding.

 

 

FIGURE . (A) Meckel’s diverticulum. (B) Technetium scan positive for bleeding Meckel’s diverticulum (arrow).

 

After intravenous injection of the isotope, the gamma camera is used to scan the abdomen. This procedure usually lasts approximately 30 minutes. Gastric mucosa detects the radioactive isotope; thus, if the diverticulum contains parietal cells in the gastric mucosa, it is depicted as a hot spot.

Traditional small-bowel series using barium has been unreliable in the detection of Meckel diverticulum. However, for patients requiring barium study, enteroclysis is considered to be a better technique for this purpose. This procedure involves using a continuous infusion of barium with adequate compression of the ileal loops and intermittent fluoroscopy to detect Meckel diverticulum.

A barium enema can be performed if intussusception is suspected.

Abdominal CT is usually not helpful because differentiating Meckel diverticulum from the small-bowel loops is difficult.

Recently, ultrasonography has been used in some cases of Meckel diverticulum. Ultrasonography tends to be helpful if the patient presents with complications of Meckel diverticulum.

Treatment.

Medical Care. The emergency department evaluation and treatment of patients depends on the clinical presentation.

Because most symptomatic patients are acutely ill, establish an intravenous line immediately, start crystalloid fluids, and keep the patient oothing by mouth (NPO) status.

If significant bleeding occurs, perform a transfusion of packed red cells.

A patient presenting with intestinal obstruction may require nasogastric decompression.

When a child presents with bleeding, specifically a dark tarry stool, perform a gastric lavage to rule out upper GI bleeding. If the gastric lavage is negative for bleeding, consider an upper endoscopy and flexible sigmoidoscopy.

Administer a regimen of antibiotics, , whenever acute Meckel diverticulitis, strangulation, perforation, or signs of sepsis are present. Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the clinical setting.

Surgical Care. The presence of peritoneal signs or hemodynamic instability demands urgent surgical intervention.

Definitive treatment of a complication, such as a bleeding Meckel diverticulum, is the excision of the diverticulum along with the adjacent ileal segment. Excision is carried out by performing a wedge resection of adjacent ileum and anastomosis, with the use of a stapling device. Adjacent ileum is included in the resection because ulcers frequently develop in the adjacent part of the ileum.

 

Successful resection of a Meckel diverticulum can also be accomplished through laparoscopy, using an endoscopically designed autostapling device.

In some cases of Meckel diverticulum, a primitive persistent right vitelline artery originating from the mesentery has been found during operation. When present, the artery is found to supply the Meckel diverticulum; therefore, it must be identified and ligated during the operation.

Management of Meckel diverticulum in asymptomatic patients is controversial.

In the past, if a Meckel diverticulum was encountered in a patient undergoing abdominal surgery for some other intra-abdominal condition, many surgeons recommended its removal.

Recently, this practice has been challenged because of a 4.2% likelihood of complications in Meckel diverticulum; the risk of complications decreases with increasing age. This would mean that, assuming a 6% mortality rate, 400 asymptomatic diverticula would have to be excised to save one patient.

On the other hand, others disagree on the premise that prophylactic removal of a diverticulum is a simple operation, whereas management of a complication of Meckel diverticulum is associated with high morbidity and mortality rates. In this approach, the only exception to excision is if the diverticulum is so broad based or so short that stapled excision cannot be performed technically. Fortunately, patients are less likely to develop complications in both of these situations.

Complications. Because the diagnosis of Meckel diverticulum is usually quite elusive, a high index of suspicion is warranted to correctly and expeditiously diagnose this condition. Complicated Meckel diverticulum can lead to significant morbidity and mortality, most often due to a delay in diagnosis. For example, a higher incidence of intestinal infarction has been encountered in patients presenting with intestinal obstruction. Causes of mortality include strangulation, perforation, exsanguination due to delay in resuscitation, and meningitis. The mortality rate in patients with Meckel diverticulum can vary from 2.5-15%. Postoperative morbidity has been reported to be 6-30%.

 

2.3. Colonic polyposis

Incidence

Intestinal polyps are much less common in children than in adults, and their association with syndromatic clusters is very common. Malignant transformation except in the syndromatic cases is less than in adults, and the approach to management is more expectant. Approximately 1% of children have asymptomatic intestinal juvenile polyps which are benign. Other types of polyps are much rarer.

Etiology and Pathology

The etiology of polyps in children is multifactorial and depends on the type of polyp. Etiologies and pathologic features will be discussed individually in the classification section.

Clinical Presentation

Bleeding

Lower intestinal bleeding is the hallmark presentation of most polypoid conditions. The bleeding is frequently associated with crampy abdominal pain. The blood is usually red, indicating its origin in the lower gastrointestinal tract, and small in quantity, unlike bleeding from duplications or Meckel’s diverticula with peptic ulceration.

If the bleeding is from polyps in the small bowel, the blood will appear darker. In the rare cases of duodenal or gastric polyps, rectal bleeding may appear black (i.e., melena).

Pain

Crampy abdominal pain is a frequent symptom along with bleeding. The pain does not necessarily occur with the bleeding.

Intussusception

Traction on a polyp may cause intussusception anywhere it occurs. Usually, colocolonic intussusception occurs only when a colonic polyp serves as a lead point. The symptoms include crampy, intermittent pain, bleeding from venous engorgement of the mucosa, and signs of intestinal obstruction (i.e., vomiting, distention, obstipation). Unlike idiopathic intussusception, intussusception from a polyp occurs in older children and may not be reduced with contrast enema.

Diagnosis

The diagnosis of polypoid lesions depends primarily on two modalities: intestinal contrast studies and endoscopy.

 

Endoscopy is advantageous as it can be both diagnostic and therapeutic. Contrast studies for colonic polyps can be very accurate and can be used to follow polyps for changes iumber and size. Upper intestinal polyps in the stomach and duodenum are also accurately visualized with contrast studies.

 

Small bowel polyps may be difficult to image even with small bowel enemas. Small bowel polyps are notoriously difficult to diagnose, and thankfully, occur only very rarely. Diagnoses is most often made at the time of laparotomy when bleeding or obstructive symptoms have prompted an operation.

Classification

Benign

Isolated Juvenile polyps

These are the most common polypoid lesion of infancy and childhood. The peak age of incidence is between the ages of 3 and 10 years. As with most polyps, crampy abdominal pain and bleeding with bowel movements are the presenting symptoms. Juvenile polyps are hamartomatous excrescencies of the intestinal mucosa. They appear to lengthen from traction caused by peristalsis and the flow of intestinal contents. There is no malignant potential, and juvenile polyps naturally auto-amputate if given enough time. Seventy-five percent of juvenile polyps occur in the rectum and sigmoid colon, but juvenile polyps may occur in the right colon as well.

Peutz-Jeghers Syndrome

This well-known syndrome causes polyps predominantly in the small bowel. Its hallmark distinguishing feature is the pigmented lesions observed on the buccal mucosa and lips of these patients. Malignant degeneration can occur, and lifelong surveillance is necessary.

 

Adenomatous Polyp

This lesion is rare but known to occur in childhood (Fig. 52.1). Malignant degeneration can occur as in the adult-type lesion. Familial adenomatous polyposis (FAP) is a syndrome that results in multiple colorectal polyps (see below). Traditionally, the presence of at least one hundred individual polyps is required to make this diagnosis.

 

Hemangiomatous Polyps

Hemangiomatous polyps cause profuse bleeding and occur predominantly in the distal small bowel. Profuse bleeding may require excision if it occurs repeatedly. They tend to regress with time as do most hemangiomas after the age of two years.

Fig. 52.1. Two sessile, adenomatous polyps in a young girl whose mother and four

sisters all had familial polyposis.

 

Malignant

Juvenile Polyposis and Familial Adenomatous Polyposis (FAP)

Juvenile polyposis is an autosomal dominant disorder which causes polyps predominantly in the large and small bowel. The lesions resemble adenomatous polyps individually but are actually mucous-retention polyps. These polyps can occur anywhere along the gastrointestinal tract. It is considered a premalignant condition and 6% of these children will eventually develop malignancy. Familial adenomatous polyposis is characterized by hundreds of adenomatous polyps in the rectum and colon causing diarrhea and bleeding. It also shares an autosomal dominant pattern of inheritance. Malignant degeneration in one or more polyp is virtually certain before the age of twenty years.

Adenocarcinoma

Although rare, isolated colonic or small bowel adenocarcinoma can occur in childhood. It can be mistaken for a juvenile polyp until it has advanced beyond the stage where it can be excised completely. Adenocarcinomas usually arise from villous adenomas.

Lymphoma

Small bowel lymphoma is usually a non-Hodgkin’s B cell lymphoma. The two most common gastrointestinal sites of non-Hodgkin’s lymphoma are the distal small bowel and the stomach. Proximal gastric lesions may be visualized and biopsied endoscopically although the lesion originates in the submucosa. In the small bowel, CT scanning can usually image the lesion if it has attained sufficient size to cause symptoms. Lymphoma of the bowel is rare in infancy, but the incidence increases with advancing age peaking in adolescence. Bleeding is the main symptom from gastric lesions. Small bowel lymphomas cause crampy abdominal pain, and may result in intussusception. Some may erode and perforate into the free abdominal cavity presenting as gastrointestinal perforation.

Treatment

The treatment of polyps of the GI tract in children can vary from simple observation of benign lesions to wide excision and chemotherapy for malignant ones. Juvenile polyps should be removed endoscopically once diagnosed. This is done to stop the symptoms as well as establish the diagnosis. Most are within easy reach of a flexible sigmoidoscope and can be snared around the stalk.

 

There is rarely more than one lesion and removal is curative. Cecal or ascending colonic polyps can be observed as long as the lesions do not grow and exceed 2 centimeters in diameter. However, with the widespread use of colonoscopy in pediatrics, endoscopic removal of these lesions is now the treatment of choice in this previously hard to reach area. The overall guiding principle in the treatment of Peutz-Jeghers polyps should be one of bowel conservation. Since the entire gastrointestinal tract can be affected, excision of all affected areas could easily result in intestinal insufficiency. Regular surveillance through endoscopy or small bowel contrast studies should be done to detect polyps which are growing and could be malignant. Large polyps or those causing significant symptoms should be removed. Endoscopic removal should be attempted first. For lesions normally beyond the range of normal endoscopy, a combined endoscopic-surgical approach can be attempted where the surgeon at laparotomy guides the endoscopist through the small bowel for visualization and removal of large lesions. Resection of segments of bowel should be reserved only for cases where cancer has developed and invaded the submucosa, or in areas where polyps are particularly dense and causing severe symptoms. Duodenal polyposis may be a very difficult problem. Although most polyps can be excised endoscopically or surgically, diffuse duodenal involvement with bleeding has been treated with pancreaticoduodenectomy. Lymphomatous lesions are surgically removed. Perforations or areas of intussusception are resected. Radical surgery with lymph node dissection is unnecessary as all these patients require systemic chemotherapy. Staging with CT scanning and bone marrow sampling are necessary, and most patients require insertion of subcutaneous reservoirs for long-term chemotherapy. The outlook for small bowel lymphoma depends on the staging and cellular subtype. Prognosis for this disease has been steadily improving with the advent of more effective chemotherapeutic regimens.

Treatment of children with familial adenomatous polyposis (FAP) involves not only the individual involved but should also extend to others in the family. Family members should be screened and referred for genetic counseling and genetic analysis. Definite genetic markers have been identified in this family of disorders, which may include other syndromes such as Gardner’s syndrome (multiple osteomas, fibromas, epidermoid cysts). The surgical treatment of FAP requires planning the process with the family and the patient. It is customary to do a complete colonic and rectal removal with a sphincter saving operation in early adolescence. This generally occurs at a time when the patient understands and can participate in treatment planning and execution.

A Soave type operation (endorectal pullthrough) is the one most commonly used. The mucosa of the distal rectum is stripped and the terminal ileum is pulled through. Both straight pull throughs and reservoir operations in the form of a J or S pull through have been advocated. Patients have attained the size where a stapling device can be used to construct both the reservoir and perform the lower anastomosis. It is customary to protect the pouch and the anastomosis with a loop ileostomy which is then closed 4-6 weeks later after all the suture lines have healed and a contrast study of the pouch has demonstrated no leaks. The prognosis when the disease is treated in a timely fashion is excellent. Periodic studies to inspect the remaining native anal mucosa is essential for the early detection of new lesions which can be easily ablated. Genetic counseling is essential so that all family members can be screened and so that all patients affected by the disease can consider the risks to their own children. All other lesions are exceptionally rare in children including the adenomatous polyp or frank carcinoma. Treatment always includes endoscopic removal whenever possible, saving surgical resection for cases where this is impractical or contra-indicated (i.e., invasive cancer).

 

2.4. Anal Fissure

Incidence

An anal fissure is a tear in the mucosa and die anoderm lining the anal canal. These lesions are common in infancy and are the most common cause of bright red blood per rectum in that age group.

Etiology

Anal fissures occur in the setting of constipation and passage of large, hard stools that cause a mechanical rear of the anal mucosa. Diarrhea can cause a chemical irritation from stool alkalinity. Pain associated with anal fissures may potentiate constipation and seems to be related to hyper tonicity of the anal sphincters.

Clinical Presentation

Anal fissures in children most commonly occur during infancy The usual pre­senting symptom in that age group is bright red blood per rectum. Crying with bowel movements and hard stool streaked with bright-red blood are the common findings observed by the parents.

Gently spreading the anus (also having the older child bear down), exposes the dentate line and the longitudinal tear comes into view. Fissures are most commonly located in the posterior midline and distal to the dentate line.

 

 An unhealed fissure may become infected and evolve into a chronic ulcer. If this occurs a sentinel skin tag forms distal to the fissure, and the anal papilla may hypertrophy. Fissures are sometime multiple and may occur anteriorly Fissures located laterally suggest Crohn’s disease or immunodeficiency states. Chronic anal fissures in older children may indicate inflammatory bowel disease.

Diagnosis and Treatment

Anal fissures are diagnosed from history and physical. Acute fissures respond to gentle anal dilation, stool softeners, laxatives, and Sitz baths. If fissures are second­ary to underlying conditions, treatment is directed to these conditions as well. Fissures associated with inflammatory bowel disease may be treated with metronidazole. Topical anesthetic ointments alter each bowel movement reduce sphincter spasm and pain. A hypertonic anal sphincter may be treated with botulinum toxin and topical nitroglycerine or a lateral subcutaneous internal sphincterotomy. Chronic anal ulcers are surgically excised eliminating granulation/scar tissue while preserving the sphincters. Leukemia and chronic immunosuppression are contraindications to surgical intervention since such fissures fail to heal until these problems are addressed.

Outcomes

Most acute fissures respond to conservative measures and heal within 10-14 days. Recalcitrant fissures respond to lateral internal sphincterotomy This procedure quickly relieves symptoms in 95% of cases and recurrence is less than 5%.

 

 

2.5. Hemorrhoids

Hemorrhoids in children are unusual. Four to five percent of children with por­tal hypertension may develop symptomatic bleeding rectal varices. The clinical pre­sentation is variable with thrombosis occurring most frequently in teenagers. Hemorrhoid thrombosis is frequently associated with heavy physical activity Symp­toms may be a report of a perianal mass that prolapses, rectal bleeding, or perianal itching. Children with hemorrhoids frequently have an anal ulcer with a prominent skin tag, rectal prolapse, or rectal polyp. Rectal duplications can rarely present as an external hemorrhoid. Physical exam and history are usually adequate to establish the diagnosis.

Treatment

When bleeding occurs in children with portal hypertension, sclerotherapy may be attempted, however, direct oversewing is the definitive therapy. In children with thrombosed hemorrhoids therapy depends on timing of presentation. If seen within the first 24 hours of symptoms, incision and clot removal provides immediate relief if pain is the presenting symptom. After the first day, spontaneous resolution is underway. Rest, analgesics, stool softeners, and Sitz baths are then the treatment of choice. Hemorrhoidectomy, the surgical procedure of choice, is reserved for chronic hemorrhoids that do not respond to medical therapy. It has a low recurrence rate (< 0.5%). Hemorrhoid surgery is contraindicated in most children who are immunocompromised. Sclerotherapy or rubber-band ligation are recommended over formal hemorrhoidectomy in children with hemorrhoids and concomitant inflam­matory bowel disease.

 

 

3. Portal Hypertension

Portal hypertension may be defined as a portal pressure gradient of 12 mm Hg or greater and often is associated with varices and ascites.

The portal venous system carries all blood from the abdominal GI tract, spleen, pancreas, and gallbladder back to the heart through the liver. The portal vein is formed by the union of the superior mesenteric and splenic veins. At the porta hepatis it divides into the right and left branches, which are segmentally distributed intrahepatically; the terminal portal venules drain into the sinusoids. In the resting state, the portal vein carries about 1 to 1.2 L/min of blood (about 75% of total hepatic blood flow) and provides 2/3 of the liver’s O2 supply. The portal vein is valveless; thus, pressure in the portal system depends on the product of input from blood flow in the portal vein and total hepatic resistance to outflow. Normal pressure in the portal vein is between 1 and 4 mm Hg higher than the free pressure in the hepatic vein, or up to 6 mm Hg higher than right atrial pressure. Portal hypertension is defined as pressures above these limits.

Pathophysiology. Two important factors exist in the pathophysiology of portal hypertension: vascular resistance and blood flow.

Increase in vascular resistance.  The lengths of the blood vessels in the portal vasculature are relatively constant. Thus, changes in portal vascular resistance are determined primarily by blood vessel radius. Because portal vascular resistance is indirectly proportional to the fourth power of the vessel radius, small decreases in the vessel radius cause large increases in portal vascular resistance and, therefore, in portal blood pressure.

Liver disease is responsible for a decrease in portal vascular radius, producing a dramatic increase in portal vascular resistance. In cirrhosis, the increase occurs at the hepatic microcirculation (sinusoidal portal hypertension). Increased hepatic vascular resistance in cirrhosis is not only a mechanical consequence of the hepatic architectural disorder, but a dynamic component also exists due to the active contraction of myofibroblasts, activated stellate cells, and vascular smooth-muscle cells of the intrahepatic veins.

Endogenous factors and pharmacological agents that modify the dynamic component include those that increase hepatic vascular resistance and those that decrease hepatic vascular resistance. Factors that increase hepatic vascular resistance include endothelin, alpha-adrenergic stimulus, and angiotensin II. Factors that decrease hepatic vascular resistance include nitric oxide, prostacyclin, and vasodilating drugs (eg, organic nitrates, adrenolytics, calcium channel blockers).

Increase in portal blood flow. The second factor that contributes to the pathogenesis of portal hypertension is the increase in blood flow in the portal veins, which is established through splanchnic arteriolar vasodilatation caused by an excessive release of endogenous vasodilators (eg, endothelial, neural, humoral). The increase in portal blood flow aggravates the increase in portal pressure and contributes to why portal hypertension exists despite the formation of an extensive network of portosystemic collaterals that may divert as much as 80% of portal blood flow.

Manifestations of splanchnic vasodilatation include increased cardiac output, arterial hypotension, and hypervolemia. This explains the rationale for treating portal hypertension with a low-sodium diet and diuretics to attenuate the hyperkinetic state.

Histologic Findings: On liver biopsy, histologic findings are varied and depend not only on the cause of liver disease but also on the cause of portal hypertension. Zone 3 necrosis can be observed in portal hypertension secondary to congestive heart failure and Budd-Chiari syndrome. In cases of normal liver parenchyma, investigate for prehepatic causes of portal hypertension.

Classification

This traditional classification is somewhat arbitrary, since the actual site of resistance in many conditions is unclear. In practical terms, almost all presinusoidal conditions are associated with relatively well-preserved liver function, whereas the sinusoidal and postsinusoidal conditions generally have cirrhosis or otherwise deranged function. Therefore, bleeding or surgery is generally better tolerated by the patient with presinusoidal hypertension.

I. PRESINUSOIDAL

extrahepatic:

portal vein obstruction (extrinsic compression, phlebitis, coagulopathy, tumor invasion, pancreatitis, neonatal omphalitis)

dynamic: traumatic/neoplastic arterioportal fistula

segmental portal HTN: splenic/SMV occlusion

intrahepatic (obstruction of portal venules):

congenital hepatic fibrosis

primary biliary cirrhosis

sarcoid

myelofibrosis

schistosomiasis

idiopathic noncirrhotic fibrosis

Wilson disease

reticuloendotheliosis

chronic malaria

toxic fibrosis (arsenic, copper, PVC vapors)

SINUSOIDAL

cirrhosis

sclerosing cholangitis

POSTSINUSOIDAL

Budd-Chiari syndrome (obstruction of major hepatic veins; etiology: thrombus (dehydration, sepsis, polycythemia vera, paroxysmal nocturnal hemoglobinuria), congenital (web in hepatic v. or IVC), tumor or other mass (eg, hydatid cyst), sickle cell anemia, trauma)

constrictive pericarditis

congestive heart failure.

Symptoms, Signs

Most clinical consequences of portal hypertension can be attributed to the development of portosystemic collateral vessels to return splanchnic blood to the heart. These vessels may form at several sites in the gut circulation. The most important are esophageal varices, formed by gross dilation of esophageal submucosal veins. These vessels carry blood from the coronary veins of the portal system into the azygos-hemiazygos veins. Other collateral sites include the umbilical vein into the omphalomesenteric vein. This occasionally results in striking dilation and prominence of the collateral vessels on the anterior abdominal wall with centrifugal radiation outward from the umbilicus, a pattern known as caput medusae. Rarely, a venous hum may be heard over such dilated veins (Cruveilhier’s sign). Other sites of collateral formation include the retroperitoneal cavity, splenorenal veins between the left kidney and the spleen, and vessels between the rectal and inferior mesenteric circulations. The latter results in large dilated, inferior rectal veins, often mistaken as gross hemorrhoids. Rarely, collaterals can develop in atypical sites (eg, duodenum, colon, or vagina). Portopulmonary collaterals have also been described.

These collateral vessels result in shunting of portal blood into the systemic circulation, causing high systemic concentrations of several hormones and substances normally extracted by the liver. The pathogenesis of hepatic or portosystemic encephalopathy is often ascribed to a failure of the liver to degrade a putative metabolic toxin produced in the gut.

Since cirrhosis is the dominant cause of portal hypertension in the West, presentation will be that of cirrhosis with decompensation, or directly attributable to portal hypertension. Signs of liver disease include the following: fscites, jaundice, spider angiomas, palmar erythema, asterixis, testicular atrophy, gynecomastia, Dupuytren contracture, muscle wasting, splenomegaly.

The medical history from a patient with portal hypertension should be directed towards determining the cause of portal hypertension and, secondarily, the presence of the complications of portal hypertension.

Determining the cause of portal hypertension involves the following: history of jaundice, history of blood transfusions, intravenous drug use (hepatitis B and C), pruritus, family history of hereditary liver disease (hemochromatosis, Wilson disease).

Determining the presence of the complications of portal hypertension involves the following:

Hematemesis or melena (gastroesophageal variceal bleeding or bleeding from portal gastropathy)

Mental status changes such as lethargy, increased irritability, and altered sleep patterns (presence of portosystemic encephalopathy)

Increasing abdominal girth (ascites formation)

Abdominal pain and fever (spontaneous bacterial peritonitis [SBP], which also presents without symptoms)

Hematochezia (bleeding from portal colopathy)

Mortality/Morbidity: Variceal hemorrhage is the most common complication associated with portal hypertension. Almost 90% of patients with cirrhosis develop varices, and approximately 30% of varices bleed. The first episode of variceal hemorrhage is estimated to carry a mortality rate of 30-50%.

Lab studies include the following:

Liver function tests

Prothrombin time

Albumin

Viral hepatitis serologies

Platelet count

Antinuclear antibody, antimitochondrial antibody, antismooth muscle antibody

Iron indices

Alpha1-antitrypsin deficiency

Ceruloplasmin, 24-hour urinary copper – To be considered only in individuals aged 3-40 years who have unexplained hepatic, neurologic, or psychiatric disease

Imaging studies.

Duplex-Doppler ultrasonography. Ultrasound (US) is a safe, economical, and effective method for screening for portal hypertension. It also can demonstrate portal flow and helps in diagnosing cavernous transformation of the portal vein, portal vein thrombosis, or splenic vein thrombosis.

Features suggestive of hepatic cirrhosis with portal hypertension include the following:

Nodular liver surface is suggestive. However, this finding is not specific for cirrhosis and can be observed with congenital hepatic fibrosis and nodular regenerative hyperplasia.

Splenomegaly is a suggestive finding.

Patients may demonstrate the presence of collateral circulation.

CT scan. Findings suggestive of portal hypertension include the following:

Collaterals arising from the portal system are suggestive of portal hypertension.

Dilatation of the IVC also is suggestive of portal hypertension.

 

Magnetic resonance imagin (MRI) provides qualitative information similar to CT scan when Doppler findings are inconclusive. MRI angiography detects the presence of portosystemic collaterals and obstruction of portal vasculature. MRI also provides quantitative data on portal venous and azygos blood flow.

Procedures.

Hemodynamic measurement of portal pressure. Direct portal measurements usually are not performed due to the invasive nature, the risk of complications, and the interference of anesthetic agents on portal hemodynamics. The most commonly used method is measurement of the hepatic venous pressure gradient (HVPG), which is an indirect measurement that closely approximates portal venous pressure.

A fluid-filled balloon catheter is introduced into the femoral or internal jugular vein and advanced under fluoroscopy into a branch of the hepatic vein. Free hepatic venous pressure (FHVP) then is measured.

The balloon is inflated until it is wedged inside the hepatic vein, occluding it completely, thus equalizing the pressure throughout the static column of blood. The occluded hepatic venous pressure (ie, wedged hepatic venous pressure) minus the unoccluded, or free, portal venous pressure (ie, FHVP) is the HVPG.

Endoscopy.

Perform upper endoscopy, as appropriate, to screen for varices in every patient with suggestive findings of portal hypertension. Additionally, all patients with cirrhosis should be considered for the presence of varices at the time of the initial diagnosis of cirrhosis. Gastroesophageal varices confirm the diagnosis of portal hypertension; however, their absence does not rule it out.

 

In compensated patients without varices, repeat endoscopy at 2- to 3-year intervals to evaluate for the development of varices.

In compensated patients with small varices, repeat endoscopy at 1- to 2-year intervals to evaluate the progression of varices.

Treatment

Treatment is directed at the cause of portal hypertension. Gastroesophageal variceal hemorrhage is the most dramatic and lethal complication of portal hypertension. Bleeding from esophageal varices ceases spontaneously in as many as 40% of patients. Each episode of variceal bleeding is associated with a 30% mortality rate and occurs mostly in patients with severe liver disease and in those with early rebleeding. Rebleeding occurs in 40% of patients within 6 weeks.

Medical care includes emergent treatment, primary prophylaxis, and elective treatment.

Emergent treatment

Following resuscitation, treatment of acute variceal bleeding includes control of bleeding (24 h without bleeding within the first 48 h after starting therapy) and prevention of early recurrence.

Initial resuscitation with replacement of blood volume loss. Blood should be replaced at a modest target of HCT of 25-30%. Avoid intravascular volume and variceal overexpansion to prevent rebleeding.

Diagnosis of source of bleeding

Prevention of complications (eg, hepatic encephalopathy, bronchial aspiration, renal failure, systemic infections, SBP). All patients with cirrhosis and upper GI bleeding are at a high risk of developing severe bacterial infections, which are associated with early rebleeding. The use of prophylactic antibiotics has been demonstrated to decrease the rate of bacterial infections and increase survival rates.

Specific treatment of bleeding lesion.

Pharmacological therapy

Somatostatin is an endogenous hormone that decreases portal blood flow by splanchnic vasoconstriction at pharmacological doses, without significant systemic adverse effects.

Octreotide is a synthetic analogue of somatostatin that usually is administered at a constant infusion of 50 mcg/h. Octreotide has been shown to be effective in reducing the complications of variceal bleeding after emergency sclerotherapy. Its efficacy as first-line treatment for variceal bleeding has not been established.

Vasopressin is the most potent splanchnic vasoconstrictor. It reduces blood flow to all splanchnic organs, decreasing portal venous inflow and decreasing portal pressure. Use of vasopressin is limited by adverse effects related to splanchnic vasoconstriction (eg, bowel ischemia) and systemic vasoconstriction (eg, hypertension, myocardial ischemia). Continuous infusion of 0.2-0.4 IU/min (not to exceed 0.8 IU/min) is recommended. Vasopressin always should be accompanied by intravenous nitroglycerin at a dose of 40 mcg/min (not to exceed 400 mcg/min) to maintain systolic blood pressure greater than 90 mm Hg.

Adding nitrates to vasopressin therapy significantly improves efficacy.

Endoscopic therapy

Endoscopic therapy has the advantage of allowing specific therapy at the time of diagnosis.

Efficacy in achieving hemostasis is higher than 80%, but its effectiveness declines to 70% at day 5 due to very early rebleeding in some patients.

Failures of endoscopic treatments may be managed by a second session of endoscopic treatment, but no more than 2 sessions should be allowed before deciding to perform transjugular intrahepatic portosystemic shunt (TIPS) or surgery.

Endoscopic injection sclerotherapy involves injecting a sclerosant solution into the bleeding varix, obliterating the lumen by thrombosis, or into the overlying submucosa, producing inflammation followed by fibrosis. Several different sclerosants are available: 5% sodium morrhuate, 1% to 3% sodium tetradecyl sulfate, and 5% ethanolamine oleate. The typical volume used per injection is 1-2 mL of sclerosant, with the total volume ranging from 10-15 mL.

Complications of endoscopic injection sclerotherapy, which are more frequent in acute bleeding than in elective situations, are related to the toxicity of the sclerosant and include transient fever, stricture, dysphagia, perforation (rarely), chest pain, mediastinitis, ulceration, and pleural effusion.

Endoscopic injection sclerotherapy is very effective emergency treatment for acute variceal bleeding (not optimal for patients bleeding from gastric fundal varices). It is the criterion standard in the management of acute variceal hemorrhage.

Endoscopic variceal ligation (EVL) is achieved by a banding device attached to the tip of the endoscope. The varix is aspirated into the banding chamber, and a trip wire dislodges a rubber band carried on the banding chamber, ligating the entrapped varix. One to 3 bands are applied to each varix, resulting in thrombosis. EVL is less prone to complications than injection sclerotherapy. EVL has the same limitations of availability, cost, and difficulty in treating gastric varices as sclerotherapy.

Emergency sclerotherapy has been compared to emergency EVL. The combined results of 9 published trials comparing sclerotherapy with EVL (in patients who are bleeding acutely) demonstrated no statistically significant difference in control of bleeding between the 2 techniques. Further studies are needed to clarify this issue completely due to the small number of patients included in these studies.

Endoscopic administration of cyanoacrylate monomer (superglue) in gastric varices is another intervention.

Balloon-tube tamponade.

Balloon-tube tamponade should be used only in massive bleeding as a temporizing measure until definitive treatment can be instituted. An endotracheal tube should be placed to protect the airway before attempting to place the balloon tube. Complications are esophageal and gastric ulceration, aspiration pneumonia, and esophageal perforation. Continued bleeding during balloon tamponade indicates an incorrectly positioned tube or bleeding from another source.

The Minnesota tube has 4 lumens, 1 for gastric aspiration, 2 to inflate the gastric and esophageal balloons, and 1 above the esophageal balloon to suction secretions to prevent aspiration. The tube is inserted through the mouth, and its position within the stomach is checked by auscultation while injecting air through the gastric lumen. The gastric balloon is inflated with 200 mL of air. Once fully inflated, the gastric balloon is pulled up against the esophagogastric junction, using approximately 0.5 kg of traction, compressing the submucosal varices. The esophageal balloon rarely is required.

The Minnesota tube is an adaptation of the Sengstaken-Blakemore (S-B) tube, the difference is that the S-B tube does not have the esophageal suction port to prevent aspiration.

Primary prophylaxis.

Primary prophylaxis is administered to patients at high risk of bleeding. These patients have large varices, red wale markings on the varices, and severe liver failure.

Beta-blockers include propranolol and nadolol. They are used most commonly. Beta-blockers are noncardioselective and reduce portal and collateral blood flow. Reduction in cardiac output (blockade of beta1-adrenoreceptors) occurs. Splanchnic vasoconstriction (blockade of vasodilatory adrenoreceptors of the splanchnic circulation) also occurs.

Vasodilators. Isosorbide mononitrate (ISMN) is a vasodilator and has been demonstrated to reduce HVPG markedly in acute administration but significantly less after long-term administration due to probable development of patient tolerance.

Vasodilators also reduce esophageal variceal pressure. The primary concern in patients with advanced cirrhosis is that vasodilators can reduce arterial blood pressure and promote the activation of endogenous vasoactive systems that may lead to sodium and water retention.

Combination therapy. This involves both beta-blockers and ISMN. A large, double-blind, placebo-controlled trial was unable to demonstrate a significantly lower rate of first hemorrhage in the group treated with combination therapy versus beta-blockers alone.

Combination therapy appears to be associated with increased adverse effects and a higher rate of ascites. Combination therapy cannot be recommended presently until further studies prove efficacy.

Prophylactic sclerotherapy. Randomized controlled trials on the use of sclerotherapy for primary prophylaxis produced divergent results, with some studies showing worse outcome than controls.

It has no role in primary prophylaxis.

Prophylactic endoscopic variceal ligation. EVL has been demonstrated to be more effective thao treatment in preventing the first variceal bleed.

Prophylactic EVL has been demonstrated to have an efficacy similar to beta-blockers in prevention of first variceal bleed, but with increased adverse effects.

Prophylactic EVL currently cannot be recommended as a routine measure for primary prevention but may be an option for patients with grade 3 varices who have contraindications to or cannot tolerate beta-blockers.

Elective treatment.

This is for the prevention of rebleeding. Variceal hemorrhage has a 2-year recurrence rate of approximately 80%.

Nonselective beta-blockers. Propranolol and nadolol significantly reduce the risk of rebleeding and are associated with prolongation of survival. Studies comparing propranolol with sclerotherapy in prevention of variceal rebleeding demonstrate comparable rates of variceal rebleeding and survival, but sclerotherapy was associated with significantly more complications.

Endoscopic sclerotherapy. This usually is performed at weekly intervals.

Approximately 4-5 sessions are required for eradication of varices, which is achieved iearly 70% of patients.

Endoscopic variceal ligation. EVL is associated with lower rebleeding rates and a lower frequency of esophageal strictures. Fewer sessions are required to achieve variceal obliteration when compared to sclerotherapy. EVL is considered the endoscopic treatment of choice in the prevention of rebleeding. Sessions are repeated at 7- to 14-day intervals until variceal obliteration (usually 2-4 sessions).

Combination of EVL and pharmacologic therapy. A recent randomized trial demonstrates that EVL plus nadolol plus sucralfate is more effective in preventing variceal rebleeding than EVL alone. Combination of EVL with beta-blockers seems to be reasonable for patients in whom pharmacological therapy has failed.

Surgical Care

Surgical care includes decompressive shunts, devascularization procedures, and liver transplantation.

Decompressive shunts. These include total portal systemic shunts, partial portal systemic shunts, and other selective shunts.

Total portal systemic shunts. 

These include any shunt larger than 10 mm in diameter between the portal vein (or one of its main tributaries) and the IVC (or one of its tributaries).

Eck fistula (classic end-to-side portacaval shunt described for historical interest only) was performed by Eck in dogs in the late 19th century. The portal vein is divided close to the liver, the hepatic end of the portal vein is ligated, and the splanchnic end is anastomosed to the IVC. This controls variceal bleeding and decompresses splanchnic hypertension but leaves high pressure in the hepatic sinusoids, thus ascites is not relieved.

For the side-to-side portacaval shunt, the portal vein and the infrahepatic IVC are mobilized after dissection and anastomosed. All portal flow is directed through the shunt, and the portal vein itself acts as an outflow from the obstructed hepatic sinusoids. Excellent control of bleeding and ascites is achieved in more than 90% of patients. Encephalopathy (rate of 40-50%) and progressive liver failure are possible. The procedure has relatively limited indications, which include massive variceal bleeding with ascites or acute Budd-Chiari syndrome without evidence of liver failure.

Partial portal systemic shunts.

These reduce the size of the anastomosis of a side-to-side shunt to 8 mm in diameter. Portal pressure is reduced to 12 mm Hg, and portal flow is maintained in 80% of patients.

The operative approach is similar to side-to-side portacaval shunts, except the interposition graft must be placed between the portal vein and the IVC.

Two prospective, randomized, controlled trials revealed a 90% rate for control of bleeding. Maintenance of some portal flow has decreased the incidence of encephalopathy and liver failure.

Selective shunts.

These provide selective decompression of gastroesophageal varices to control bleeding while at the same time maintaining portal hypertension to maintain portal flow to the liver.

One example is the distal splenorenal shunt, which is the most commonly used decompressive operation for refractory variceal bleeding. It is used primarily in patients who present with refractory bleeding and continue to have good liver function. It decompresses the gastroesophageal varices through the short gastric veins, the spleen, and the splenic vein to the left renal vein. Portal hypertension is maintained in the splanchnic and portal venous system, and it maintains portal flow to the liver. This shunt provides the best long-term maintenance of some portal flow and liver function with a lower incidence of encephalopathy (10-15%) compared to total shunts. The operation produces ascites because the retroperitoneal lymphatics are diverted.

Devascularization procedures

These include splenectomy, gastroesophageal devascularization, and esophageal transection (at times). Incidence of liver failure and encephalopathy is low following devascularization procedures, presumably because of better maintenance of portal flow. Devascularization could be used in patients who are not candidates for decompression in whom first-line therapy has failed. This includes patients who have portal or splenic vein thrombosis in addition to cirrhosis.

Splenectomy

The spleen is one of the major inflow paths to gastroesophageal varices. Splenectomy also allows better access to the gastric fundus and the distal esophagus to complete the devascularization.

Portal vein thrombosis of as much as 20% is reported following splenectomy. Ascites is a frequent early postoperative complication because portal hypertension is maintained.

Gastroesophageal devascularization (Sugiura procedure)

This should devascularize the whole greater curve of the stomach from the pylorus to the esophagus and the upper two thirds of the lesser curve of the stomach; the esophagus should be devascularized for a minimum of 7 cm.

In patients who have undergone extensive and repeated sclerotherapy, the gastroesophageal junction is thickened and the ability to perform a satisfactory transection is limited.

Liver transplantation

Liver transplantation is the ultimate shunt because it relieves portal hypertension, prevents variceal rebleeding, and manages ascites and encephalopathy by restoring liver function.

It is the treatment modality that has significantly improved the outcome of patients with Child-Pugh class C disease and variceal bleeding.

Using liver transplantation in most patients is impractical because some patients can be managed successfully with lesser methods; therefore, transplant must be based on appropriate patient selections. For patients with Child class A disease, shunt surgery is recommended; for patients with Child class B disease, shunt surgery or (portosystemic shunt) TIPS is appropriate; and for people with Child C class disease, TIPS or orthotopic liver transplant is recommended.

Prognosis is critically dependent on liver function. Liver failure is often the prime cause or a significant associated factor in mortality. The in-hospital (all inclusive) mortality rates with GI bleeding in Child-Pugh grade A (5 to 10%), B (15 to 25%), and C (50 to 70%) patients allow stratification of patients to improve assessment of outcome. Criteria for each grade are given in Table 1.

Table 1. Pugh modification of child-Turcotte criteria