TOPIC 10. VASCULAR INJURY
VASCULAR INJURIES IN THE ARM
Arteries and veins in the arms are the second most common location for vessel injuries in the body and constitute almost half of all peripheral vascular injuries. Much more often than in the legs they occur together with neurological and skeletal injuries. Although vascular injuries in the arms rarely lead to fatal or serious bleeding, ischemic consequences are common. The extensive collateral network around the elbow makes clinical signs variable and often minute. On the other hand, if the brachial artery is obstructed proximal to the origin of the deep brachial artery, the risk for amputation is substantial: up to 50% of such patients lose the arm if the vessel is not repaired. While the vascular injury per se often can be managed easily, it is the damaged nerves that cause the main functional disturbances in the long run.
Because arm vessel trauma is common and sometimes appear without signs and symptoms, missed injuries cause considerable morbidity in trauma patients. Awareness and optimal management may reduce this morbidity. The arteries supplying blood to the arms – the subclavian and axillary arteries – are located in the thorax or thoracic outlet, and if these vessels are traumatized, the consequences are often more serious.
Etiology and Pathophysiology
Injury mechanisms are the same in the arms and legs, and the brachial, radial, and ulnar arteries can be damaged by both penetrating and blunt trauma. Knives and gunshots usually cause penetrating injuries (most often to the brachial artery), but lacerations secondary to fractures occur regularly. Sharp fragments commonly penetrate vessel walls (Fig. 1).
Fig. 1. Angiography showing an occluded brachial
artery severed by the sharp ends of a shaft fracture of the humerus
Blunt injuries occur in road traffic accidents because of fractures and joint dislocations. The most frequent orthopedic arm injuries associated with vessel damage are listed in Table 1.
Table 1. Most common sites for combined orthopedic and vascular injury
There are also types of trauma specific for arm vessel injuries. A large number of upper limb vascular trauma are caused by industrial and domestic accidents. Splintered glass as well as self-in-flicted wounds regularly damage vessels below the elbow. The popularity of using the brachial artery as a site for vascular access for endovascular procedures has caused an increase in iatrogenic catheter-related injuries to the brachial artery in proximity to the elbow. Pseudoaneurysms are often caused by radial artery punctures for arterial blood samples.
As in all traumatized vessels, transection or laceration may cause bleeding, thrombosis, or both. Transections, intimal tears, and contusions are more frequent after blunt trauma. Tissue in the distal parts of the arm is as susceptible to ischemia as in the legs, and the time limit of 6–8h before irreversible damage occurs is also valid for arm injuries. Concomitant nerve injuries, as mentioned, are the main cause of morbidity long term. Such injuries are equally common after penetrating and blunt trauma. In the literature, 35–60% of arterial injuries in the upper arm are associated with nerve injuries, and over 75% are associated with nerve, bone, or venous damage.
Clinical Presentation
Medical History
Patients with vascular injuries in the arms arrive at the emergency department after accidents, knife or shooting assaults, or car crashes causing multiple injuries. As with all injuries, it is important to interview the rescue personnel and accompanying persons about the type of injury and the type of bleeding. The exact time of the injury should be established to facilitate planning of repair. Because orthopedic injuries are associated with arterial damage, it is also essential to ask whether joint dislocations or fractures were noted or reduced. Complaints of pain from areas around a joint indicate a possible luxation. Even more important is to ask for symptoms of nerve damage, including permanent or transient numbness and impaired motor function in any part of the arm.
Clinical Signs and Symptoms
Both the “hard” and the “soft” signs of vascular trauma occur after upper extremity vascular injuries. Examples, in descending frequency of occurrence, include diminished or absent radial pulse, motor deficit, sensory loss, hemorrhage, and expanding hematoma. It is common for a diminished radial pulse or an abnormal brachial blood pressure to be the only sign of vascular obstruction. Because pulse wave propagation through a thrombus is possible, a palpable radial pulse does not completely exclude arterial obstruction; therefore, a high suspicion of arterial injury is necessary even when a palpable pulse is found. As a guideline, a difference of more than 20 mmHg in blood pressure between the arms should make the examiner suspect a vascular injury. Inability to move the fingers, hands, and arms as well as disturbances in sensation are frequently associated with vascular injury. The sensory and motor functions must therefore be carefully examined and evaluated to disclose any nerve damage that should be repaired. A list of what this examination should cover is given in Table
Diagnostics
Investigations beyond the physical examination of the patient should be done only in stable patients. Accordingly, most patients with distal arm injuries can undergo angiography or duplex scanning provided that these investigations do not delay treatment. Arteriography is indicated when arterial involvement not is obvious. For example, patients with trauma in the elbow region – blunt or penetrating – with clear ischemia and no radial pulse do not need arteriography before surgery.
If the patient has multiple injuries, shotgun injuries, or suspected proximal arterial involvement, arteriography is recommended to determine the exact site of injury. Arteriography should also be done when there are indistinct signs of ischemia and arterial injury is only suspected. Included in this indication for arteriography is the so-called proximity injury, referring to injury in patients without signs of distal ischemia but with trauma in close proximity to a major artery. Of patients undergoing arteriography for this indication, 10–20% are reported to have arterial lesions. If the arteriogram reveals injury to the subclavian or axillary artery, endovascular treatment can proceed right away. Duplex scanning has replaced arteriography in some hospitals and is probably just as accurate in experienced hands. Intimal flaps and small areas of vascular wall thrombosis may be difficult to identify with duplex scanning under some circumstances, but such small lesions in the arm can, on the other hand, usually be treated without exploration.
Computed tomography (CT) angiography is an important modality for diagnosing proximal arterial injuries in particular. It is reported to be at least as accurate as arteriography in this area. The use of CT angiography is likely to increase in the near future because it is quicker than angiography, and most trauma centers have rapid access to good-quality CT.
Management Before Treatment
Severely Injured and Unstable Patients
Patients arriving to the emergency department with active serious bleeding after a single injury to an arm are rare. When this does occur, manual direct pressure over the wound can control the bleeding while general resuscitation measures according to Advanced Trauma Life Support principles are undertaken: oxygen, monitoring of vital signs, placement of intravenous (IV) lines, and infusion of fluids . It is important not to forget to administer analgesics (5–10mg of an opiate IV) and, when indicated, antibiotics and tetanus prophylaxis.
Multiply injured patients with signs of arm ischemia should be treated according to the hospital’s general trauma management protocol, and the vascular injury is usually evaluated during the second survey. Serious ongoing bleeding has high priority, but arm ischemia should be managed after resuscitation and treatment of life-threatening injuries but before orthopedic repair in most circumstances. When the patient has stabilized, arteriography can be performed if indicated.
Less Severe Injuries
Most patients with arm injuries arrive in the emergency department in a stable condition without ongoing bleeding but with signs of hand ischemia. For these patients, careful examination of the arm including assessment of nerve function, is essential. Dislocated fractures or luxations should be reduced under proper analgesia. After reduction, examination of vascular function should be repeated. If the radial pulse and distal perfusion return, the position should be stabilized and fixed. Repeated examinations during the following 4hare mandatory to ensure that the returned perfusion is persistent.
If the vessel injury is definite – an absent radial pulse and reduced hand perfusion – and the site of vascular injury is apparent, the patient can be transferred to the operating room without further diagnostic measures. Patients with findings indicating vascular injury at examination, and those with obvious arterial disruption but with arms so traumatized that the site of arterial injury cannot be determined, should undergo arteriography or duplex scanning. Expediency of repair is required for all locations of arterial injuries in the arm. The proposed time limits indicating a low risk for permanent tissue damage range from 4h for brachial artery injuries and up to 12h for forearm injuries. The risk limit for irreversible ischemia following forearm injuries is valid for patients with an incomplete palmar arch. The frequency of this anatomical variation is 20% in most Western populations.
Suspected injuries to the radial and ulnar artery should be treated according to the general principles discussed above. Even cases with normal perfusion in the hand but without a radial pulse should be explored and repaired if reasonably simple. When forearm arterial injury is unclear, the Allen test (Table 2) can be added to the examination procedure. A positive Allen test together with a history of trauma to an area in close proximity indicate that the radial or ulnar artery is indeed affected. The wound should then be explored and the traumatized artery inspected and mended. Patients with multiple severe injuries and high-risk patients should not be explored if perfusion to the hand is rendered sufficient. For those circumstances, repeat examinations every hour are mandatory to make sure that perfusion is adequate and stable.
Table 2. Allen test
Amputation
Some arms with vascular injuries are so extensively damaged that amputation is a treatment option. The decision of when to perform a primary amputation versus trying to repair vessels, nerves, tendons, and muscles is difficult. As a general principle, arms with multiple fractures, nerve disruption, ischemia-time longer than 6h, and extensive crush injuries involving muscle and skin will never regain function and should be amputated. Another principle is that when four out of the five components of the arm are injured – skin, bone, muscles, and vessels – but there is only minor nerve injury, an attempt to save the arm is reasonable. One must keep in mind, however, that the arm needs at least some protective sensation in order to be functional. Children have a greater chance of regaining a functional arm than adults do, and a generous attitude to surgical repair in children is recommended.
The mangled extremity severity score (MESS) is a grading system designed to aid the decision process for managing massive upper and lower extremity trauma. A score of 7 or more has been proposed as a cut-off value for indicating when amputation cannot be avoided and should be performed as the primary procedure. In some studies, a score 7 predicted an eventual amputation with 100% accuracy. The basis of the MESS scoring system is given in Table 3. As shown in Table 3.4, a crush injury is regarded as particularly unfavorable. The duration of ischemia is also a significant factor taken into account in the MESS system.
Table 3. MESS: Mangled Extremity Severity Score (BP blood pressure)
Operation
Preoperative Preparation
Hemodynamically stable patients are placed on their back with the arm abducted 90º on an arm surgery table. The forearm and hand should be in supination. Peripheral or central IV lines should not be inserted on the injured side. Any continuing bleeding is controlled manually directly over the wound. If the site of injury is the brachial artery or distal to it, a tourniquet can be used to achieve proximal control. It is then placed before draping and should be padded to avoid direct skin contact with the cuff. This minimizes the risk for skin problems during inflation. The arm is washed so the skin over the appropriate artery can be incised without difficulty. The draping should allow palpation of the radial pulse and inspection of finger pulp perfusion. One leg is also prepared in case vein harvest is needed.
The position of the arm is the same for more proximal injuries. Proximal control of high brachial and axillary artery trauma may involve exposure and skin incisions in the vicinity of the clavicle and the neck, so for proximal injuries the draping must also allow incisions at this level.
Proximal Control
For distal vessel injury, proximal control can be achieved by inflating the previously placed tourniquet to a pressure around 50 mmHg above systolic pressure. The cuff should be inflated with the arm elevated to minimize bleeding by venous congestion. After inflation, the wound is explored directly at the site of injury.
For more proximal injuries, control is achieved by exposing a normal vessel segment above the wounded area. The most common sites for proximal control in the arm are the axillary artery below the clavicle, and the brachial artery (which is what the artery is called distal to the teres major muscle) somewhere in the upper arm.
Exposure for Proximal Control of Arteries in the Arm
Axillary Artery Below the Clavicle
An 8-cm horizontal incision is made
Fig. 2
Brachial Artery in the Upper Arm
The incision is made along the posterior border of the biceps muscle; a length of 6–8 cm is usually enough (Fig. 3.). The muscles are retracted medially and laterally, and the artery lies in the neurovascular bundle immediately below the muscles. The sheath is incised and the artery freed from the mediaerve and the medial cutaneous nerve that surrounds it.
Fig. 3. Transverse incision in the elbow for exposing the brachial artery and with possible elongations (dottedlines) when access to the ulnar and radial ranches
as well as to more proximal parts of the brachial artery is needed
Brachial Artery at the Elbow
The incision is placed
Exploration and Repair
Distal control is achieved by exploring the wound. Sometimes this requires additional skin incisions. The most common site for vascular damage in the arm is the brachial artery at the elbow level. These injuries occurs, for example, because of supracondylar fractures in children and adults. In such cases, exposure and repair of the brachial artery through an incision in the elbow crease is appropriate. Hematomas should be evacuated to allow inspection of nerves and tendons.
For supracondylar fractures, the brachial artery, the mediaerve, and the musculocutaneous nerves must sometimes be pulled out of the fracture site. Before the artery is clamped, the patient is given 50 units of heparin/kg body weight IV. Repair should also be preceeded by testing inflow and backflow from the distal vascular bed by temporary tourniquet or clamp release. It is often also wise to pass a #2 Fogarty catheter distally toensure that no clots have formed. Occasionally, inflow is questionable, and proximal obstruction must be ruled out. As a general principle, all vascular injuries in the arms should be repaired, except when revascularization may jeopardize the patient’s life. Arterial ligation should be performed only when amputation is planned. Postoperative arm amputation rates are reported to be 43% if the axillary artery is ligated and 30% at the brachial artery level. Another exception is forearm injuries. When perfusion to the hand is rendered adequate – as assessed by pulse palpation and the Allen test – one of these two arteries can be ligated without morbidity. In a substantial number of patients with differing vessel anatomy, however, ligation of either the ulnar or radial artery may lead to hand amputation. If both arteries are damaged, the ulnar artery should be prioritized because it is usually responsible for the main part of the perfusion to the hand.
For most arterial injuries, vein interposition is necessary for repair. Veins are harvested from the same arm, from parts of the cephalic or basilic vein if the trauma is limited, or from the leg. The saphenous vein in the thigh is suitable for axillary and brachial artery repair, while distal ankle vein pieces can be used for interposition grafts to the radial and ulnar arteries. Before suturing the anastomoses, all damaged parts of the artery must be excised to reduce the risk of postoperative thrombosis. Rarely, primary suture with and without patching can be used to repair minor lacerations. Shunting of an arterial injury to permit osteosynthesis is rarely needed in the arm. Vascular interposition grafting can usually be done with an appropriate graft length before final orthopedic repair. Also, extremity shortening due to fractures is less of a problem in the arms (in contrast to the legs), and orthopedic treatment without osteosynthesis is common especially in older patients. Nevertheless, for some arm injuries shunting is a practical technique that allows time for fracture fixation, thus avoiding the risks of redisplacement and repeated vessel injury. One example is injuries to the axillary or brachial artery caused by a proximal humeral fracture, where the fragment needs to be fixed in order to prevent such injuries. Another example is humeral shaft fracture, which needs to be rigidly fixed to abolish the instability that may otherwise endanger the vascular graft. Veins should also be repaired if reasonably simple. If the vein injury is caused by a single wound with limited tissue damage, concomitant veins to the distal brachial artery can be ligated. For more extensive injuries where the superficial large veins are likely to be ruined, it is wise to try to repair the deep veins. For very proximal injuries in the shoulder region, vein repair is important to avoid longterm problems with arm swelling. It is also important to cover the mended vessel segment with soft tissue to minimize the risk for infection that may involve the arteries.
Finishing the Operation
When the repaired artery or graft’s function is doubtful and when the surgeon suspects distal clotting, intraoperative arteriography should be performed. After completion, all devitalized tissue should be excised and the wound cleaned. For penetrating wounds, damaged tendons and transected nerves should also be sutured. This is not worthwhile for most blunt injuries. Fasciotomy should also be considered before finishing the operation. As in the leg, long ischemia times and successful repair increase the risk of reperfusion and compartment syndrome, but the overall risk for compartment syndrome is reported to be less in the arm than in the leg. For a description of arm fasciotomy techniques, we recommend consulting orthopedic textbooks. After the wounds are dressed, a fractured arm is put into a plaster splint for stabilization.
Endovascular Treatment
In contrast to proximal arm vessel trauma, there are few instances in distal injuries when endovascular treatment is a feasible treatment option. Because the brachial artery and the forearm vessels are easy to expose with little morbidity, open repair during exploration of the wound is usually the best option. Possible exceptions to this are treatment of the late consequences of vascular trauma, such as arteriovenous fistulas and pseudoaneurysms. Especially in the shoulder region, including the axilla, primary endovascular treatment is often the best treatment option. Another circumstance when endovascular treatment is favorable is bleeding from axillary artery branches – such as the circumflex humeral artery – due to penetrating trauma. Active bleeding from branches, but not from the main trunk, observed during arteriography is preferably treated by coiling. The bleeding branches are then selectively cannulated with a guidewire and coiled, using spring coils or injections of thrombin to occlude the bleeding artery.
Management After Treatment
Postoperative monitoring of hand perfusion and radial pulse is recommended at least every 30 min for the first 6 h. When deteriorated function of the repaired artery is suspected, duplex scanning can verify or exclude postoperative problems. Apparent occlusions should be treated by reoperation as soon as possible. Compartment syndrome in the lower arm may also evolve over time, and swelling, muscle tenderness, and rigidity must also be monitored during the initial days. For most patients, treatment with low molecular weight heparin is continued postoperatively. A common dose is 5,000 units subcutaneously twice daily.
Keeping the hand elevated as much as possible may reduce swelling of the hand and arm as well as problems with hematoma formation around the wound. Early mobilization of the fingers facilitate blood flow to the arm and should be encouraged.
VASCULAR INJURIES IN THE LEG
Vascular trauma to extremity vessels is caused by violent behavior or accidents. Because of the rise in the number of endovascular procedures, iatrogenic injuries have also become an increasing part of vascular trauma. Vascular injuries may cause life-threatening major bleeding, but distal ischemia is more common. Ischemia occurs after both blunt and penetrating trauma. The vascular injury is often one of many injuries in multiply traumatized patients that make the recognition of signs of vascular injury – which can be blurred by more apparent problems – and thediagnosis difficult. Table 9.1 lists common locations of combined orthopedic and vascular injury. Multiple injuries also bring problems regarding priority.
Table 4. Most common locations for combined orthopedic and vascular injury
Data on the true incidence of vascular injuries to the legs is hard to gather. The incidence of vascular trauma varies among countries and also between rural and urban areas. It is usually higher where gunshot wounds are common. There is an equal share of blunt and penetrating injury in most studies from Europe, whereas penetrating injury is slightly more common in the
Etiology and Pathophysiology
Penetrating Injury
Penetrating vascular injury is caused by stab and cutting injuries, gunshots, and fractures, the latter when sharp bone fragments penetrate the vascular wall. Gunshots cause major bleeding by direct artery trauma, while high-velocity bullets create a cavitation effect with massive soft tissue destruction and secondary arterial damage. In fact, after all types of penetrating trauma both bleeding and indirect blunt arterial injury with ischemia may occur. Bleeding is more often exsanguinating after sharp injury and partial vessel transection. Complete avulsion, especially when caused by blunt trauma, makes the vessel more prone to retraction, spasm, and thrombosis. This diminishes the risk for major bleeding. Iatrogenic injuries can be caused by catheterization and during surgical dissection.
Blunt Injury
Blunt vascular injuries are usually caused by motor vehicle and other accidents. The consequences are thrombosis and ischemia distal to the injured vessel. The media and the intimal layers of the vessel wall are easily separated, and subsequent dissection by the bloodstream between the layers may lead to lumen obstruction. Blunt injuries also induce thrombosis. This type of vessel injury is particularly common when the artery is hyperextended as in knee joint luxations and upper arm fractures. Contusion of the vessel may also cause bleeding in the vessel wall. Thrombosis and ischemia by this mechanism can occur several hours after the traumatic situation. Narrowing of the arterial lumen following blunt trauma is rarely caused by spasm and it can be disregarded as etiology.
Pathophysiology
The main pathophysiological issue after vascular injuries to the extremities is ischemia. The process is identical to what happens during acute leg ischemia due to embolization . Irreversible damage to the distal parts of the legs is not infrequent and the diagnosis is more difficult to determine than for other types of leg ischemia. The reason is the multiple manifestations of the trauma. It must be kept in mind that the time limit for acute leg ischemia – 4–6 h before permanent changes occur – is also valid for trauma.
A vascular injury missed during the initial examination may develop into a pseudoaneurysm or an arteriovenous fistula. A pseudoaneurysm is a hematoma with persistent blood flow within it that may enlarge over time and cause local symptoms and sometimes even rupture. When both an artery and an adjacent vein are injured simultaneously an arteriovenous fistula may develop. These can become quite large with time and even cause cardiac failure due to increased cardiac output.
Medical History
Most patients with major vascular injury present with any or several of the “hard signs” of vessel injury (Table 5) and the diagnosis is obvious. Penetrating injury patients who arrive in the emergency department without active hemorrhage are usually not in shock because the bleeding was controlled at the trauma scene. Shock in patients with penetrating injury usually means that the bleeding is ongoing. Still, information about the trauma mechanism is ofteeeded to estimate the likelihood for vessel injury and to facilitate the management process.
Besides interviewing the patient, additional background information may be available from medical personnel and accompanying persons. The few minutes required to establish a picture of the trauma situation are usually worthwhile. For example, a history of a large amount of bright red pulsating bleeding after penetrating trauma suggests a severe arterial injury. Venous bleedings are often described as a steady flow of dark red blood. In high-impact accidents the risk for a severe vascular injury is increased.
Besides being helpful when assessing the risk for a major injury estimation of the blood loss is also important for later volume replacement. Knowledge of the exact time when the injury happened is helpful for determining the available time before irreversible damage occurs from ischemia. The duration of ischemia also influences the management priority in multitrauma patients, and the time elapsed affects the presentation of the ischemic symptoms. For example, an initial severe pain may vanish with time as a consequence of ischemic nerve damage. Even a major internal hemorrhage may be present without being clinically obvious after a very recent injury. Information about complicating diseases and medication is also helpful. For instance, betablockers may abolish the tachycardia in hypovolemia.
Table 5. Signs of vascular injury
Clinical Signs and Symptoms
The physical examination is performed after the primary and secondary surveys of a multitrauma patient and should focus on identifying major vessel injury. The examination should be thorough, especially regarding signs of distal ischemia. It should include examination and auscultation of the injured area, palpation of pulses in both legs, and assessment of skin temperature, motor function, and sensibility. The presence of one or more of the classic hard signs of vascular injury listed in Table 5 suggests that a major vessel is damaged and that immediate repair is warranted. Findings of “soft” signs should bring the examiner’s attention to the fact that a major vessel may be injured but that the definite diagnosis requires additional work-up. As noted in Table 5, the hard sign of distal ischemia as suggested by the “six Ps” suggests vascular injury.
The principles of the vascular examination suggested for acute leg ischemia are also valid for vascular injuries, but certain details need to be emphasized. Vascular trauma in the legs usually strikes young persons, so it should be assumed that the patient had a normal vascular status before the injury. A palpable pulse does not exclude vascular injury; 25% of patients with arterial injuries that require surgical treatment have a palpable pulse initially. This is due to propagation of the pulse wave through soft thrombus. Pulses may be palpated initially in spite of an intimal flap or minor vessel wall narrowing and can later cause thrombosis and occlude the vessel. Ankle pressure measurements and calculation of the ankle brachial index (ABI) should therefore supplement palpation of pulses. If the ABI is ≤0.9, arterial injuries should be suspected.
Findings in the physical examination of a patient in shock are particularly difficult to interpret. In several aspects findings of distal ischemia caused by vascular injury are similar to vasoconstriction of the skin vessels in the foot. Differences in pallor, the presence of pulses, and skin temperature between the injured and uninjured leg therefore should be interpreted as the possible presence ofvascular injury. Ankle pressure measurements are also valuable during such circumstances.
It is important to remember to listen for bruits and thrills over the wounded area to reveal a possible arteriovenous fistula.
Diagnostics
Recommendations for management of suspected vascular injuries in the leg have evolved from mandatory exploration of all suspected injuries (a common practice during past wars), to routine angiography for most patients, to a more selective approach today. Regarding exploration and subsequent angiography, it was found that negative explorations and arteriograms were obtained in over 80% of the patients. The associated risk for complications and morbidity after these invasive procedures is the rationale for a more selective approach. Rapid transportation, clinical examination, ankle pressure measurements, careful monitoring, and duplex examination leave angiography for some of the patients and urgent exploration for a few.
Angiography
Angiography is unnecessary when a vascular injury is obvious after the examination. The two most common indications for excluding vascular injury are (1) when there are no hard signs at the examination, and (2) when clinical findings are imprecise but the ABI is <0.9.
Angiography is more often indicated after blunt trauma than penetrating. The reason for this is the more difficult clinical examination because of the more extensive soft tissue and nerve damage after blunt trauma. It may occasionally be helpful to perform angiography even when injury is evident in order to exactly locate the injured vessel. An option is to perform it intraoperatively. Contralateral puncture is important when the injury is close to the groin.
The purpose of the arteriography is to identify and locate lesions such as occlusions, narrowing, and intimal flaps. Contrast leakage outside the vessel can be visualized, and it also serves to provide a road map before surgery. It has, however, been argued that it is unnecessary to search for minimal lesions; some studies have shown that it is safe and effective to manage such lesions nonoperatively. On the other hand, angiography may be the first step in the final treatment of such small lesions by stenting. When the injury is caused by a shotgun blast, angiography should always be performed because multiple vascular injuries are common. It is then indicated regardless of the clinical signs and symptoms. The risk for complications after angiography is very low, but the risk of complications is higher when the punctured artery is small. Children therefore have a rather high rate of complications. A contributing factor is that their very vasoactive arteries are prone to temporary spasm. Overall, as described above, the risk for complications after angiography does not warrant avoiding it when indicated. Occasionally it is worthwhile to order venography. It may be indicated in patients not subjected to exploration because arterial injury was ruled out but in whom a major venous injury is suspected. As an example, 5–10% of all popliteal venous injuries are reported to occur without arterial damage.
Duplex Ultrasound
Despite the usefulness of duplex scanning in general for vascular diagnosis, it has not been universally accepted for diagnosis of vascular trauma despite the fact that it is noninvasive. It is operator dependent and vessels may be difficult to assess in multiply injured patients, legs with skeletal deformities, large hematomas, and through splints and dressings. In some hospitals with expertise in duplex assessment and round-the-clock access to skilled examiners, duplex has replaced angiography to a large extent. The indications proposed are then the same as for angiography. Duplex is also the method of choice for diagnosis of most of the late consequences of vascular injuries to the legs – arteriovenous fistulas, pseudoaneurysms, and hematomas.
Management Before Treatment
Severe Vessel Injury
Major external bleeding not adequately stopped when the patient arrives to the emergency department should immediately be controlled with digital pressure or bandages. No other measures to control bleeding are taken in the emergency department and attempts to clamp vessels are saved for the operating room.
The patient is surveyed according to the trauma principles used in the hospital. For most patients without obvious vascular injuries to the leg vessels, more careful vascular assessment takes place after the secondary survey. If the vascular injury is one of many in a multitrauma patient, general trauma principles for trauma care are applied. Treatment of the vascular problem is then initiated as soon as possible when the patient’s condition allows it.
Patients with hard signs of vascular injury but without other problems should be transferred immediately to the operating room. Before transfer the following can be done:
1.Give the patient oxygen.
2.Initiate monitoring of vital signs (heart rate, blood pressure, respirations, SpO2).
3.Place at least one large-bore intravenous (IV) line.
4.Start infusion of fluids. Dextran preceded by 20ml Promiten is advised especially if the patient has distal ischemia.
5.Draw blood for hemoglobin and hematocrit, prothrombin time, partial thromboplastin time, complete blood count, creatinine, sodium,and potassium as well as a sample for blood type and cross-match.
6.Obtain informed consent.
7.Consider administering antibiotics and tetanus prophylaxis.
8.Consider administering analgesics (5–10 mg opiate IV).
Less Severe Injuries
ABI must be measured when vascular injury is suspected. Patients with soft signs of vascular injury and an ABI <0.9 usually need arteriography to rule out or verify vascular damage. This is performed as soon as possible. Before the patient is
sent to the angiosuite other injuries need to be taken into account and the priority of management discussed. Ischemic legs should be given higher priority than, for example, skeletal and soft tissue injury, and temporary restoration of blood flow can be achieved by shunting.
Patients with an ABI >0.9 and a normal physical examination (little suspicion of vascular injury) can be monitored in the ward. Repeated examinations of the patient’s clinical status are important and hourly assessment of pulses and ABI the first 4–6 h are warranted. If the ABI deteriorates to a value <0.9 or if pulses disappear, angiography should be carried out.
Angiography Findings
Operative treatment and restoration of blood flow are done as soon as possible if the angiography shows arterial occlusion in the femoral, popliteal, or at least two calf arteries in proximity to the traumatized area. It should be kept in mind that occlusion of the popliteal artery is detrimental for distal perfusion and is associated with a high risk for amputation due to a long ischemia time. Patients with popliteal occlusion should therefore be taken immediately to the operating room. Debate is ongoing whether one patent calf artery in an injured leg is sufficient to allow nonoperative treatment. Some reports have found that as long as one of the tibial vessels is intact, there is no difference in limb loss or foot problems during follow-up between operative and nonoperative treatment. Our recommendation, however, is to try to restore perfusion if more than one of the calf arteries is obstructed. If combined with ischemic symptoms or signs of embolization, angiography findings of intimal flaps, minor narrowing of an artery, or minor pseudoanuerysm (<
Primary Amputation
In most circumstances, but not always, it is reasonable to repair injured vessels. For a few patients, however, primary amputation is a better option. This is often a difficult decision. Primary amputation is favorable for the patient if the leg is massacred or if the duration of ischemia is very long (>12 h) and appears to be irreversible in the clinical examination. Primary amputation may also be considered for certain patients: multitrauma patients, patients with severe comorbid disease, and those in whom the leg was already paralyzed at the time of injury. Extensive nerve damage, lack of soft tissue to cover the wound, and duration of ischemia >6 h support primary amputation for these patient groups.
There are scoring systems, such as the Mangled Extremity Severity Score (MESS), to aid in making the decision to amputate a leg or an arm. For example, a patient over 50 years old with persistent hypotension and a cool paralyzed distal leg after high-energy trauma should have the leg amputated according to MESS. It must be stressed, however, that repair of both venous and arterial injuries is superior for most patients.
Operation
Surgical treatment of vascular injuries in the leg usually proceeds in a particular order common for most patients. First the patient is scrubbed, anesthetized, and prepared for surgery. The next step is to achieve proximal control. Occasionally, control of the bleeding by manual compression with a gloved hand needs to be maintained throughout these first two steps. Proximal control is followed by measures to achieve distal control, often accomplished during exploration of the wound. Finally, the vessels are repaired and the wound cov-ered with soft tissue. When the patient has other injuries that motivate urgent treatment, or has fractures in the leg that need to be surgically repaired, this last step can be delayed while perfusion to the distal leg is maintained by a shunt temporarily bypassing the injured area.
Preoperative Preparation
The patient is placed on a surgical table that allows x-ray penetration. If not administered previously, infection prophylaxis treatment is started. The entire injured extremity is scrubbed with the foot draped in a transparent plastic bag. A very good marginal of the sterile field is essential because incisions need to be placed much more proximal than the wound to achieve proximal control. The contralateral leg should also be scrubbed and draped to allow harvest of veins for grafts. The venous system in the injured leg should be kept intact if possible. If a patient is in shock and the bleeding is difficult to control, it is recommended to delay inducing the anesthesia until just before the operation begins in order to avoid increased bleeding and an accentuated drop in systemic blood pressure due to loss of adrenergic activity.
Proximal Control
In patients with injuries proximal to the femoral vessels, control is achieved through an incision in the abdominal fossa. The common or external iliac artery can then be exposed retroperitoneally and secured. Proximal control for injuries in the thigh, proximal to the poplital fossa, is usually obtained by exposing the common femoral artery and its branches in the groin. Popliteal vessel trauma can be controlled by exposing the distal superficial femoral artery or the proximal popliteal artery through a medial incision above the knee. Inflow control for calf vessel injuries is reached by exposing the popliteal artery below the knee.
If there is no ongoing bleeding when the artery is exposed a vessel-loop is applied. Clamping should be postponed until later. If bleeding is brisk and continuous, however, the clamp is placed right away. Clamping should be attempted even if the bleeding appears to be mainly venous in origin. Arterial clamping often diminishes such bleedings substantially.
An alternative way to achieve proximal control of distal femoral, popliteal, and calf vessels is to use a cuff. A padded cuff, the width in accordance with the leg circumference, is then wrapped around the leg well above the wounded area before scrubbing and draping. In the thigh a 20-cm wide cuff is often suitable. It is important to have at least
Exposure of Different Vessel Segments in the Leg
Common or External Iliac Arteries, Fig.
a A skin incision
Fig.
b The muscles are split in the direction of the fibers. Dissection is totally retroperitoneal, with attention to the ureter crossing the vessels in this region. Be careful with the iliac vein, which is separated from the artery by only a thin tissue layer. Exposure of the proximal common iliac artery and the aortic bifurcation is facilitated by a table-fixed self-retaining retractor (i.e., Martin arm).
Fig. 4 B. Exposure of common or external iliac arteries.
Femoral Artery in the Groin, Fig.
a A longitudinal skin incision starting 1–2 cm cranial to the inguinal skin fold and continued lateral to the artery is used to avoid the inguinal lymph nodes. A common mistake is to place the incision too far caudally, which usually means the dissection is taking place distal to the deep femoral.
Fig 5A. Exposure of femoral artery in the groin
b The dissection is continued sharply with the knife straight down to the fascia lateral to the lymph nodes and is then angulated 90° medially to reach the area over the artery. It should then be palpable. Lymph nodes should be avoided to minimize the risk for infection and development of seroma. The fascia is incised, and the anterior and lateral surfaces of the artery are approached.
Fig. 5. Exposure of femoral artery in the groin
c At this stage the anatomy is often unclear regarding the relation of branches to the common femoralartery. Continue dissection until the bifurcation into superficial and deep femoral artery is identified. Its location varies from high up under the inguinal ligament up to
During the continued dissection, attention must be given to important branches that should be controlled and protected from iatrogenic injuries. These are, in particular, the circumflex iliac artery on the dorsal aspect of the common femoral artery and the deep femoral vein crossing over the anterior aspect of the deep femoral artery just after its bifurcation. To provide a safe and good exposure of the deep femoral to a level below its first bifurcation, this vein must be divided and suture-ligated. Partial division of the inguinal ligament is occasionally needed for satisfactory exposure.
Fig.
Superficial Femoral Artery, Fig. 6.
A skin incision is made along the dorsal aspect of the sartorius muscle at a midthigh level. It is important to avoid injuries to the greater saphenous vein, which usually is located in the posterior flap of the incision. The incision can be elongated as needed. After the deep fascia is opened and the sartorius muscle is retracted anteriorly, the femoral artery is found and can be mobilized. Division of the adductor tendon is sometimes required for exposure.
Fig. 6. Incision for exposure of the supericial femoral artery
Popliteal Artery Above the Knee, Fig.
a The knee is supported on a sterile, draped pillow. The skin incision is started at the medial aspect of the femoral condyle and follows the anterior border of the sartorius muscle 10–15 cm in a proximal direction. Protect the greater saphenous vein and the saphenous nerve during dissection down to the fascia. After dividing the fascia longitudinally, continue the dissection in the groove between the sartorius and gracilis muscles, which leads to the fat in the popliteal fossa.
Fig. 7 . Exposure of popliteal artery above the knee
b The popliteal artery and adjacent veins and nerve are then, without further division of muscles, easily found and separated in the anterior aspect of the fossa.
Fig. 7 B. Exposure of popliteal artery above the knee
Popliteal Artery Below the Knee, Fig.
a A sterile pillow or pad is placed under the distal femur. The incision is placed 1 or
Fig.
b The popliteal fossa is reached by retracting the gastrocnemius muscle dorsally. The deep fascia is divided and the artery usually easier to identifiy. Occasionally, pes anserinus must be divided for adequate exposure. The popliteal artery is often located just anterior to the nerve and in close contact with the popliteal vein and crossing branches from concomitant veins. If it is necessary to expose the more distal parts of the popliteal artery, the soleus muscle has to be divided and partly separated from the posterior border of the tibia.
Fig. 8. B. Exposure of popliteal artery below the knee
Distal Control and Exploration
Distal control is achieved by distal elongation of the incision used to explore the site of injury. Through this incision careful dissection in intact tissue distal to the injured area usually reveals the injured artery. When it is identified and found to be not completely transected, a vessel-loop is positioned around it. If the artery is cut, a vascular clamp is applied on the stump. It is also possible to gain distal control during the exploration of the injured area, but dissection may be tricky because of hematoma, edema, and distorted anatomy. Usually the backbleeding from the distal artery is minimal and does not disturb visualization during dissection. Simultaneous venous bleeding that emerges from major veins must also be controlled. This can be done by balloon occlusion or clamps. The latter should be used with caution and closed as little as possible.
When control is obtained the wound is explored and the site of vessel injury identified. The best way is to follow the artery proximally from where the artery was exposed for distal control. Of course, any foreign materials encountered need to be removed. The injured artery should be explored in both directions until a normal arterial wall is reached. Several centimeters of free vessels are needed. Side branches are controlled using a double loop of suture with a hanging mosquito or by small vascular clamps. Thrombosed arteries usually have a hematoma in the vessel wall giving it a dark blue color. Such parts need to be cut out and the vessel edges trimmed before shunting or repair. For penetrating injuries all parts of the vascular wall that are lacerated must be excised to ensure that theintima will be enclosed in the suture line during repair. After this procedure the vessel can be shunted or repaired.
Finally, other parts of the wound are explored and all devitalized skin and muscle tissue is excised. Injured small adjacent veins should be ligated and all larger veins, such as the femoral veins and the popliteal vein, must be repaired.
Shunting
Insertion of a temporary shunt to restore distal perfusion is sensible if the vascular injury appears to require more extensive repair than a simple suture or an end-to-end anastomsis. Shunting prvides the time needed to either perform a vascular reconstruction, including harvesting of a vein graft from the uninjured leg, or to wait for help. Shunting can also be valuable when patients have other injuries that need attention or when leg fractures must be repositioned to give the appropriate vascular graft length. In patients with fractures shunting allows both repositioning and fixation without increasing the risk of ischemic damage.
A novel vascular reconstruction seldom tolerates the forces required for reposition of fractures. When perfusion is restored by a shunt the surgeon has plenty of time to carefully explore the wound and other injuries. When a shunt is used for distal perfusion while other procedures are performed, it is important to check its function at least every 30min.
The principles of vascular shunting are simple. Specially designed shunts can be used if available; examples are Pruitt–Inhara and Javid. Most have inflatable balloons in both ends for occlusion and side channels with stopcocks through which the function of the shunt can be tested (Figs. 9, 10). The side holes also enable infusion of a heparinized solution and contrast for fluoroscopy. The extra channels can be used to draw blood during the operation. It is not, however, necessary to use manufactured shunts. Any kind of sterile plastic or rubber tubing is sufficient. It is then important to use dimensions of the tube in accordance with the artery’s inner diameter. The tube is cut into suitable lengths and the edges carefully trimmed with scalpel and scissors to avoid damage when inserted. The tube is positioned and secured with vessel loops that abolish the space between the artery and tube to manage bleeding. A loosely applied suture around the middle part of the shunt can be used to secure it. It is advantageous to simultaneously shunt concomitant vein injuries – at least the femoral and popliteal veins – to avoid swelling and to facilitate distal flow.
Fig.
The shunt has a larger balloon in one end aimed for the proximal inlow vessel and a smaller one for placement in the outlow vessel. The occluding balloons are controlled by injecting saline through separate channels with stopcocks. The shunt can also be lushed through a third channel
Fig. 10. Example of shunting in a severe artery and vein injury. The artery is shunted with a Pruitt–Inahara shunt and its balloons secured with vessel-loops. For shunting of the vein a piece of ordinary rubber tubing is used. It is also secured with vessel-loops and with a suture
Vessel Repair
While we advocate repairing both the artery and the vein, we do not favor reconstructing the injured vein before the artery. If both can be mended within a reasonable timeframe we recommend that the most difficult reconstruction is performed first. If, however, the artery is shunted it may be advantageous to start with the vein to achieve optimal outflow as soon as possible. Some vascular surgeons favor vein ligature as a general principle because of the potential risk for embolization from vein segments that thrombose after repair.
Arterial Injuries
In general, all injured arteries should be repaired. Sometimes, when necessary in order to save the patient’s life or when interruption of an artery does not influence blood flow to the leg, the injured vessel may be ligated. The former is extremely uncommon, but the decision is difficult when it arises. As an aid we have listed in Table 6 the amputation rates, as obtained from the literature, following ligation of vessels. Among proximal vessels, only branches from the deep femoral artery, but not the main branch, can be ligated without morbidity. Distally, we recommend repair of at least two calf arteries to be on the safe side, but it is possible to leave two interrupted, provided the remaining vessel is not the peroneal artery.
Before definitive repair the surgeon must be sure that the inflow and outflow vascular beds remain open and are free of clots. Liberal use of Fogarty catheters is therefore wise. If the backbleeding is questionable, intraoperative angiography should be performed to make sure the outflow tract is free of clots. Local heparinization, is always indicated. Systemic heparinization can be used for selected patients without other injuries considered to have a low risk for continued bleeding from the wound after debridement. If the foot’s appearance or intraoperative angiography suggests microembolization, local thrombolysis can be tried.
The goal for repair is to permanently restore continuity of the artery without stenosis or tension. The type of injury determines the choice of technique. It varies from a couple of vascular sutures to reconstruction with a patch, interposition, or a bypass grafting. Lateral suture for repair of minor lesions, including patching.
A graft is usually needed, and only occasionally can an end-to-end anastomosis be performed without tension. It is always better to use an interposition graft or a bypass to avoid what is even perceived as insignificant tension because anastomotic rupture and graft necrosis may occur when leg swelling and movements pull the arterial ends further apart postoperatively. The major bleeding that can result from this may even be fatal.
Table 6. Amputation frequencies after ligature of
diferent arteries
An autologous vein is always the preferred graft material. Vein is more infection resistant than synthetic materials and is more flexible. It allows both elongation and vasodilatation to adjust variations in flow requirements. The great saphenous vein from the contralateral leg is the primary choice for a graft. It is a serious mistake to use the great saphenous vein from the traumatized leg if the deep vein is also injured or if injury is suspected. Interruption of the saphenous vein with obstructed concomitant deep veins will rapidly cause severe distal swelling of the leg and graft occlusion within days. The vein can be harvested at a level in the leg where the saphenous vein diameter fits the artery that needs to be repaired. A graft slightly larger than the artery should be obtained if possible. For common femoral artery lesions, two pieces of saphenous vein, both open longitudinally and then sutured together, might be required. An option is to use arm veins as graft material. If veins not are available expanded polytetrafluoroethylene (ePTFE) is the second choice. The main reasons not to use it are the slightly higher risks for postoperative graft occlusion and infection.
Venous injuries
Most venous injuries are exposed when the wound is explored. While vein ligature may lead to leg swelling, it rarely causes ischemia or amputation. On the other hand, the only benefit of vein ligature is rapid bleeding control and a reduced operating time. Major veins can therefore be ligated to save the life of an unstable patient. If possible, however, most veins should be repaired, especially the popliteal and the common femoral veins. Calf veins can be ligated without morbidity. In patients with combined injuries, both the vein and the artery should be repaired to enhance the function of the arterial reconstruction. Control of bleedings can be achieved by fingers or a “strawberry” or “peanut” to compress the vein proximal and distal to the injured site, or by using gentle vascular clamps. A continuous running suture, almost without traction in the suture line, is often sufficient to close a stab wound. When the vein is more extensively damaged, a patch or an interposition graft may be needed for repair. As with arteries, it is important to match the caliber of the interposition graft and the injured vein. Veins without blood are collapsed, so it is easy to underestimate their size. An autologous vein is preferred over synthetic materials.
Finishing the Operation
After the vascular reconstruction is finished the resulting improvement in distal perfusion should be checked. This is indicated as well-perfused skin in the foot and palpable pulses. If there is any doubt about the result control angiography should be performed. Preferably, it is done from the proximal control site to enable visualization of all anastomoses. If problems are revealed the reconstruction must be redone and distal clots extracted as previously described. While vascular spasm is rare and should not be regarded as the main explanation for lack of distal blood flow, injection of 1–2 ml papaverine into the graft can also be tried.
After vascular repair all devitalized tissue and foreign material should be removed to reduce the risk of postoperative infection. Grafts and vessels should be covered with healthy tissue by loosely adapting it with interrupted absorbable sutures. For injuries with massive tissue loss it may be impossible to cover the graft. This increases the risk for postoperative anastomotic necrosis and rupture.
Endovascular Treatment
Endovascular treatment of vascular injuries to leg vessels is attractive because it provides a way to achieve proximal control, reduce ischemia time, and simplify complex procedures. There is not a lot of experience – at least not reported in the literature – with endovascular treatment. Some centers have reported successful semielective treatment of pseudoaneurysms and arteriovenous fistulas in the groin. Small patient series have been published on embolization of bleeding branches to the deep femoral artery and stent graft control of small lacerations in the femoral arteries. We have only treated occasional patients this way so far. Endovascular treatment will probably be an option for many patients with soft signs of vascular injury, who will undergo angiography and then will be found to have a minor bleeding, a pseudoaneurysm, a fistula, or an intimal flap. The possibilities of considering endovascular repair for patients with hard signs of vascular injury to the legs will depend on logistics and the organization of a hospital’s endovascular team. With around-the clock availability, patients with less severe distal ischemia may be subjected to angiography with possibilities for endovascular treatment in mind. Patients with penetrating injuries that are actively bleeding may undergo balloon occlusion of a proximal artery to accomplish control and then be transferred to the operating room for repair. In other hospitals where an endovascular team is not available during weekends, angiography is skipped in some patients with soft signs, and they are treated with an open procedure and intraoperative angiography instead. But it is likely that endovascular treatment will be the treatment of choice for a significant proportion of patients in the near future.
Management After Treatment
As for most vascular procedures, the risk for bleeding and graft thrombosis of the reconstructed artery is higher during the first 24 h after the operation. Postoperative monitoring of limb perfusion, including inspection of foot skin and wounds and palpation of pulses, is necessary at least every 30 min for the first 6 h. If pulses are difficult to ascertain, ankle pressure should be measured. Loss of pulses or an abrupt drop in pressure indicate that reoperation may be required, even when the graft appears to be patent either clinically or on duplex scanning. As for acute leg ischemia caused by thrombosis, there is also a substantial risk for compartment syndrome. Particularly when the ischemia duration has been long, this risk is considerable, and it is important to examine calf muscles for signs of compartment syndrome. This assessment includes motor function, tenderness, and palpation of the muscle compartments in the calf. Findings that may suggest fasciotomy are listed in Table 7.
Table 7. Medical history and clinical indings suggesting that fasciotomy may be needed
For most patients administration of dextran or low molecular weight heparin is indicated to avoid postoperative thrombosis. This is especially important for patients with both venous and arterial reconstruction. Patients who have been subjected to venous ligatioeed extra attention and measures against limb swelling. Antibiotic treatment started preoperatively or intraoperatively is usually continued after the operation. We use a combination of benzylpenicillin and isoxazolyl penicillin to cover streptococci, clostridia, and staphylococci.
Fasciotomy
When the compartment pressure is clearly increased or when there is a risk of developing increased pressure, fasciotomy of muscular compartments distal to a vascular injury should be performed in association with the vascular repair. Factors suggesting an increased pressure are listedTable 7.
Fasciotomy of the Calf Compartments (Two Incisions)
Medial Incision
A 15–20-cm-long skin incision, starting slightly below the midpoint of the calf and downwards parallel to and 2–3 cm dorsally of the medial border of the tibia, is used to decompress the deep and superficial posterior muscle compartments (Fig. 11). It is important to avoid injury to the great saphenous vein. Sharp division of skin and subcutaneous fat reaches the fascia. The skin and subcutaneous fat is mobilized en bloc anteriorly and posteriorly to expose it enough to provide access to the compartments. The fascia is then opened in a proximal direction and distally down toward the malleolus under the soleus muscle. At this level, the soleus muscle has no attachments to the tibia, and the deep posterior compartment is more superficial and easier to access. Through the same skin incision, the fascia of the superficial posterior muscle compartment is cleaved 2–3 cm dorsally and parallel to the former. A long straight pair of scissors with blunt points is used to cut the fascia using a distinct continuous movement in the distal direction, down to a level of
Fig. 11. Incision and exposure for fasciotomy of posterior compartments. The posteriordottedline indicates fasciotomy incision for the supericial compartment and the anteriordottedline for the deep compartment
Lateral Incision
The skin incision for fasciotomy of the lateral and anterior muscle compartments is oriented anterior to and in parallel with the fibula. The dorsal position of the lateral compartment, however, often requires more extensive mobilization of the subcutaneous fat to reach it. The superficial peroneal nerve is located anteriorly under the fascia and exits the compartment through the anterior aspect of the fascia distally in the calf. To preserve this nerve, direct the scissors dorsally when making the fasciotomy in both directions. (See Fig. 11.).
Fig. 11. Incision for fasciotomy of anterior and lateral compartments. Through the demonstrated skin incision, long incisions are made along the dottedlines in the fascia. Caution must be taken with the peroneal nerve
Unless the swelling is very extensive, 2-0 prolene intradermal suture is loosely placed to enable wound closure later (Fig. 12). It is important to leave long suture ends at both sides to allow wound edge separation the first postoperative days. The skin incisions are left open with moist dressings.
Fig. 12. Cross-section demonstrating the principles for decompression of all four muscle compartments in the calf through a medial and a lateral incision. The
location of major nerve bundles in the diferent compartments is indicated
TRAUMATIC INJURY OF THE
VENA CAVA AND ITS MAJOR BRANCHES
Trauma mechanisms
In general, the superior thoracic, intrapericardial and retrohepatic segments of the caval vein may susain either a penetrating or a closed trauma. The VC is usually involved in single penetrating injuries.
Сlosed trauma
Closed injuries usually result from a severe deceeration trauma in the horizontal direction such astraffic accidents, or in the vertical direction, likea fall from high altitude. The resulting shear orces cause a partial or total avulsion of the venous segment, as can be observed at the atriocaval or hepatocaval junctions, or at the level of the azygos, renal, or superior mesenteric veins.
The common and internal iliac veins are damaged where they pass bony structures, especially after pelvic fractures.
In the literature, 10 cases of post-traumatic thrombosis of the IVC were found in 1999, occurring 3 days to 3 years after a high-energetic trauma. This hrombosis could have been secondary to organizaion of an initially localized thrombus, which allowed spontaneous hemostasis after an injury to the vessel wall.
As an anecdote, a laceration of the IVC was reported following a nonpenetrating trauma caused by the high-pressure water jet of an industrial cleaner.
Penetrating trauma
The most frequent penetrating traumas are those from gunshots rather than stabbing weapons. The statistical preponderance of dexterity among the attackers explains why the caval vein, in its right lateral position, is spared most of the time during frontal attacks on the left part of the body.
All kinds of trauma, varying between a localized puncture and injuries with substantial tissue loss, can occur. Bullet injuries are the most destructive. Except for the trauma to the caval vein, they are often responsible for other serious lesions to neighboring structures that induce a risk of sepsis, which in part influences the prognosis.
Iatrogenic trauma
This may concern vessel wall perforations due to the introduction of an endoluminal catheter or caval filter, of which the prognosis is usually good when untreated, or injuries occurring during surgery. Trauma occurring during thoracoscopy or laparoscopy may either pass unnoticed or be revealed secondarily, or may be diagnosed directly because of excessive blood loss during the procedure.
As this type of trauma is becoming more and more frequent due to the increasing use of these techniques, it forms the topic of another chapter of this book. Finally, direct iatrogenic damage to the left innominate vein or the intrapericardial caval vein can complicate certain cardiac re-interventions.
General intervention principles
Generally speaking, no additional investigationshould interfere with the initial reanimation of a patient with an injured abdomen or thorax. Not until the condition has been stabilized can a transthoracic cardiac or abdominal ultrasound exam be performed. When the clinical suspicion of a major vascular trauma has risen, a surgical exploration is justified.
In several North American series, patients in whom reanimation remained insufficient underwent an urgent clamping of the thoracic descending aorta through a left anterolateral thoracotomy.
Although meant to restore arterial pressure in these dying patients, this heroic maneuver yielded disappointing results. In 2001 Carr et al. Reported only 14 survivors out of 151 cases in the literature treated in this manner. In another series reporting on the outcome of 302 abdominal vascular injuries, thoracotomy was performed in 131 cases (43%), of which 43 times (14%) were in the shockroom and 88 times (29%) in the operating room.
The survival rates in these two groups were only 2% and 10%, respectively. In another recent series on 136 IVC injuries, one single patient survived out of 25 who underwent a thoracotomy for clamping. These results can be explained by the fact that the most severely injured patients would obviously have died already on the site of the accident, were it not for the modern means of transport and prehospital reanimation.
Local consequences of caval vein trauma
Half of the patients who suffered from a caval vein trauma, and particularly those with an arterial lesion, present with a severe hemorrhagic shock. As opposed to the arteries, the veins show a poor vasoconstrictor response and cannot generate an effective hemostasis through their own physiologic properties.
Because of the absence of valves, IVC injuries are not only characterized by bleeding from the iliac, but also by reflux from the atrial side. These veins, however, do have some features that can lead to a spontaneous hemostasis, at least temporarily.
The circulation, including the caval veins, is maintained at low pressure. In case of an IVC injury, the neighboring tissues can cause an effective plugging that limits the hemorrhage and sometimes leads to thrombus formation and healing of the vessel wall. The hemorrhage may thus be contained by the retroperitoneum, the pancreas, the duodenum or the posterior side of the liver. This phenomenon is particularly seen in simple lesions caused by stabbing weapons or low-velocity shot wounds, but is exceptional in case of a perforating trauma of the IVC or damage secondary to highvelocity fire weapons.
Common principles of major venous injuries
Patients who make it to the operating room should be treated by a surgical team of sufficient number.
In order to respond to a possible decompensation during anesthetic induction or surgical incision, they are usually anesthetized after preparation of the skin and operation field. In most cases the patient is positioned in the dorsal decubitus position, and the operation field runs down from the thoracic and abdominal areas to the knees. The unanimously acknowledged surgical access in case of an abdominal venous injury is a median laparotomy from xyphoid to pubic area, to which a median sternotomy is added. After the intestines are moved aside, the peritoneal cavity is emptied of a variable amount of blood by means of aspiration into a reservoir. A nonpulsating hematoma of black blood directly identifies a venous injury. Continuous aspiration of it carries the risk of exsanguination and should be prohibited. Preferably, gauzes should be packed into all abdominal quadrants, as it is difficult to localize the origin of the venous bleeding, which expands like a flat surface rather than a jet.
This hemostasis enables to optimize the hemodynamic situation by correcting the volume. A temporary clampage of the infrarenal aorta only, performed without difficulty and visibly, or even simple compression, can help to reach a stable situation.
In contrast with arterial injury, for which clampng of the inflow to obtain adequate hemostasis usually suffices, hemostasis of a venous injury requires checking of both the inflow and the outflow ract. Use of conventional clamps is dissuaded, especially when they have to be applied half blindly. Moreover, the posterior side of the IVC should be checked even more carefully to avoid additional damage.
Whenever possible, hemostasis should be achieved hrough direct digital compression, fixed gauzes, covered atraumatic clamps placed under visual conrol or by using tourniquets. Most of the traumatic esions of the caval vein and its branches may then be treated by means of direct closure or simple ligature in certain localizations. The use of prosthetic material in the form of patches or tubular grafts is arely necessary. Autologous venous jugular or saphenous grafts, sometimes composed and organzed in order to obtain sufficient material for the reconstruction (helical graft), are preferred.
TRAUMA OF THE IVC
The IVC is more frequently subjected to trauma than the SVC. The abdominal vascular structure are mostly injured, mainly through a penetrating trauma, The problems of each segment are described separately.
Infrarenal IVC. The infrarenal IVC is involved in 25% to 50% of the injuries to the IVC. Its exposure via a right mediovisceral approach is preferred over a median retroperitoneal approach, which offers the right access to the abdominal aorta and the left renal vein but less to the IVC.
The coloparietal exposure is pursued while retaining the duodenal area and the head and body of the pancreas to the left. This allows exposure of the right kidney and its ureter. After rotation of the viscera, the IVC can be exposed nicely from the junction of the iliac veins to its juxtahepatic segment.
A serious hemorrhage occurring during exposure of the IVC should be compressed by an assistant to allow the surgeon to continue the exposure. Subsequently, various procedures can be chosen for the hemostasis and reconstruction. The simplest one is to apply gauze over the lesion. However, maintaining sufficient compression during the whole duration of the venous repair is difficult. Total clamping of the IVC at a distance from the lesion by means of conventional clamps or tourniquets is risky due to the vulnerability of the vessel wall and the possibility of permanent reflux supplied by the collateral circulation from the azygos and lumbar veins.
A smaller vessel wall trauma can be treated by means of bipolar endoluminal clamping using occlusive balloon catheters (Fogarty), or urinary catheters (Foley). Lesions of the anterior or lateral sides of the IVC can best be handled using a large Satinsky clamp, which has the advantage that it partially clamps the lumen and thereby does not induce venous hypertension. Direct closure is the technique of choice to repair lesions of the infrarenal IVC. In urgent cases, a quick closure using thicker stitches (3/0 or 4/0) is preferable to trying to do a more esthetical but more time-consuming reconstruction using thinner stitches. This is underlined by the finding that there is no relation between the outcome of the reconstruction and the degree of residual stenosis. Rarely, a secondary enlargement of the sutured area is required. Lesions of the posterior side can be closed, either via direct exposure by rotating the IVC after resection of one or more lumbar veins, or via a transcaval approach after having enlarged the entry opening in the anterior side, which is to be repaired afterward. In case of major destruction of the vessel wall, particularly in combination with shock and other vascular lesions, ligation of the infrarenal IVC or iliocaval junction together with ligation of all lumbar veins is generally advocated.
Juxtarenal and juxtahepatic IVC.
The juxtarenal IVC extends two centimeters above and below the junction with the renal veins. It runs upward through a short juxtahepatic IVC, accessible via the lower border of the liver. Involvement of these segments comprises 20% to 50% of the traumatic lesions of the IVC.
Access to the Juxtarenal segment is obtained by a right mediovisceral rotation (see above). Exposure of the posterior side by means of an axial rotation requires either a right retrorenal release, mobilizing the kidney to the median line, or a complete resection between two clamps of the right renal vein, which is to be reconstructed after repositioning the IVC. The juxtahepatic segment can be approached similarly, by means of a complete right mediovisceral rotation, or more selectively by mobilizing only the duodenum and pancreas. The narrow relation between the anterior side of the IVC and the posterior side of the portal vein should be kept in mind, to avoid any damage to the latter during the dissection.
The clamping techniques do not differ much from those used for the infrarenal segment. To obtain a dry operation field at the Juxtarenal level requires the simultaneous clampage of both renal veins, sometimes including the renal arteries.
Control over the inflow and outflow of the Juxtarenal segment usually does not cause any problems. However, the outflow of the juxtahepatic IVC may be difficult because it is a short segment. Exerting anteroposterior pressure on the liver and thereby compressing the end of the juxtahepatic JVC leads to the same result. Reflux from the suprarenal vein, if any, is usually minimal. The reconstruction options for the Juxtarenal and juxtahepatic segments of the IVC can be superposed on those for the infrarenal segment in case of simple lesions. They basically consist of direct closure. Although a stenosis with a 75% caliber reduction due to this suture may be acceptable, we find it important to preserve a residual lumen of at least 30% of the initial diameter. Correction of remaining stenoses regarded excessive is the only indication for enlargement procedures by means of a venous patch rather than prosthetic material. Complete replacement of this caval segment using a venous or prosthetic graft is exceptional and restricted to cases with extensive vessel wall damage in patients whose hemodynamic condition and hemostasis allow for a complex reconstruction.
INJURIES OF THE MAJOR BRANCHES
Iliac veins.
Apart from the osseous trauma to the pelvis, iatrogenic lesions from laparoscopic procedures or maneuvers to obtain control at the common iliac artery are the most common causes of this type of injury. Access to the iliocaval junction and the distal ends of the iliac veins becomes difficult due to the bleeding that quickly fills the pelvic cavity. The best route is obtained via mobilization of the right colon, retaining it to the left of the aorta and the right common iliac artery, transected between two clamps. The ureter is the only critical structure in this region. Hemostasis is obtained by compressing the IVC with gauzes against the spine and the common iliac veins against the promontory. Hemostasis of iliac vein injuries extending into the internal iliac veins is more difficult, because of their rich collateral circulation. Direct closure is standard. A too extensive venous damage should be treated with ligation of an iliac vein or iliocaval junction. The large number of side branches between the iliac veins and the reno-azygolumbar network explains why these ligations are usually well tolerated.
Renal veins.
Injuries to the renal veins accountfor 8% to 12% of abdominal vascular injuries. They occur in 6% to 13% of the IVC injuries. These veins are injured by penetrating as well as by closed traumas. Iatrogenic trauma of the left retro-aortic renal vein during abdominal aortic surgery, should be avoided by careful analysis of the pre-operative computed tomography (CT) scan. Surgical exploration of retroperitoneal peri-renal hematomas is not justified in the case of a closed trauma, until an intravenous pyelography, a renal angiogram or a CT scan in a stable patient have shown a normal renal excretion.
In contrast, surgical exploration of peri-renal penetrating injuries is standard.
The right renal vein is accessed by means of mobilization of the duodenum and colon. The left renal vein is approached via a median longitudinal incision of the retroperitoneum. To reduce the bleeding it may be useful to control and clamp the renal arteries. A lateral closure, performed under digital control, either after clamping the injured vein or after lateral clamping of the IVC at its ostium, can most often be realized. If ligation of the right renal vein is necessary, one should choose between a nephrectomy and a renal autotransplantation if the hemodynamics allow for it. Ligation of the left renal vein is well tolerated as long as the capsular and genital veins are spared.
Azygos vein.
The azygos vein can be injured hrough penetrating and closed traumas. A massive hemothorax is common and indicates an approach ia a right thoracotomy. The bleeding can be enhanced while spreading the ribs. There is a coniderable risk of air embolization, which is why one hould opt for an initial compression maneuver ather than excessive aspiration of the operation ield. Final treatment consists of ligation of the azyos vein with lateral closure of the SVC when it is сontrolled by a Satinsky clamp.
Venous brachiocephalic trunk.
The right and left venous brachiocephalic trunks join to form the SVC. A lesion at this level may extend into the SVC.
In practice, the left trunk is the most affected because of its length and its tract, which crosses the median line and is exposed particularly during sternotomies for cardiac procedures. Ligation is well tolerated without any sequelae.
Postoperative measures
Whether the lesion of the IVC is repaired, ligated or simply compressed, certain measures must be taken to prevent thrombo-embolic complications resulting from stasis of blood in the lower part of the body. These comprise elevation of the legs, elastic compression and antithrombotic drugs. There is no consensus on the anticoagulation regimen.
Late sequelae, such as deep venous insufficiency, are rare regardless of the treatment chosen.
Follow-up and prognostic factors
Iearly 50% of cases, patients suffering from a traumatic lesion of the IVC die before any treatment is given. The results of 20 series in the literature, comprising 2032 operated patients, are presented in the Table, which shows that the mortality rate for all the different locations is 44% on average, ranging from 21% to 75%. No improvement is clear with time, despite a substantial progression in treatment options. Nevertheless it is plausible that the improvement of collection and transport of the wounded has led to the operation of more and more diseased patients.
Death occurs mostly within 24 hours. In more than 90% of the cases this is due to massive bleeding, mainly during attempts to explore and repair the damage. During the early follow-up period, the bleeding induces an irreversible disseminated intravascular coagulopathy. Multi-organ failure or a sepsis, often related to intestinal lesions, are the other major causes of death after this period. The presence of shock on arrival, the existence of concomitant lesions, especially of the aorta, the closed character of the trauma, absent spontaneous hemostasis of the lesion and the retrohepatic orjuxtadiaphragmatic localization are significantly associated with a poor outcome