LECTURE 2.
OPERATIVE SURGERY OF NECK REGION AND ORGANS
The neck-is intermediate link which bridges the head and the trunk. Its area on horizontal section in adult man composes on average 130-140 sq sm. But many anatomical formations are concentrated on this comparatively small space. The numerous vessels, nerves and visceral structures found in the neck make this region both interesting and important to the surgeon.
The upper limits of the neck are the lower border of the jaw, a line extending from the angle of the jaw to the mastoid process, and the superior curved line of the occipital bone. The lower limits are the sternal notch, the clavicles and a transverse line from the acromioclavicular joint to the spinous process of the 7th cervical vertebra. The contour of the neck varies with age and sex, being well rounded in women and children but more angular in men; hence, the landmarks are more conspicuous in the male.
By the frontal plane, which passes through transversal processes of cervical vertebrae, neck is divided into two large parts: anterior and posterior. The anterior portion of the neck contains the respiratory tube (larynx and trachea) and the alimentary tube (pharynx and esophagus); the great vessels and nerves are located on the sides, and the posterior portion contains the cervical segment of the spine and surrounding musculature. The infrahyoid region extends from the hyoid bone above to the suprasternal notch below and is limited laterally by the anterior border of the sternocleidomastoid muscles.
The present of two vascular-nervous fascicles is the basis of division of a neck’s anterior part into two large triangles- anterior and posterior. At anterior triangle passes common carotid artery, jugular vein, vagus nerve. At posterior triangle passes subclaviae arterie and vein, brachial plexus.
The anterior triangle of the neck is bounded in front by the midline of the neck, which extends from the symphysis of the mandible above to the sternal notch below; behind, by the anterior border of the sternocleidomastoid; above, by the lower border of the mandible and a line drawn backward from its angle to the posterior boundary. This triangle is subdivided into 3 subsidiary triangles by the omohyoid.
The digastric triangle is bounded by the anterior belly of the digastric in front, the posterior belly of the same muscle behind, and the border of the mandible above.
The carotid triangle is bounded by the superior belly of the omohyoid below, the sternocleidomastoid behind and the posterior belly of the digastric above.
The muscular triangle is bounded by the superior belly of the omohyoid above, the sternocleidomastoid below, and the midline of the neck in front.
Submental Triangle. That region of the neck which is bounded by the body of the hyoid bone below and the anterior bellies of the digastric on each side forms the submental triangle
The posterior triangle is bounded by the posterior border of the sternocleidomastoid muscle, below by the middle third of the clavicle and behind by the anterior border of the trapezius; the apex of the triangle is the meeting point of the trapezius and the sternocleidomastoid, and when anterior and posterior borders fail to meet on this line, the area is occupied by part of the splenius capitis muscle. The inferior belly of the omohyoid muscle crosses the lower part of the posterior triangle, separating it into an upper, larger occipital triangle and a lower, smaller supraclavicular one. The roof of the posterior triangle is made up of the investing layer of the deep cervical fascia. The floor is muscular and is formed by the following three muscles from above downward: the splenius capitis, the levator scapulae and the scalenus medius. This muscular floor is carpeted by the prevertebral fascia.
STRUCTURES
Skin. The skin of the neck is loosely attached, especially anteriorly. Since it is well supplied with blood vessels, it favors plastic surgery. The skin that covers the posterior region is very thick, adherent and contains numerous sebaceous glands, which explains the frequency of furuncles and carbuncles in this area.
The subcutaneous fatty layer is evenly developed enough, though sometimes in a mental site it is possible to notice the intensified putting of adeps(double chin). On anterior surfase cervival plexus gives branches, in particular n. cutaneus medianus and nn. suprascapulares.
Neck Fasciae:
1. Superficial fascia;
2. proper fascia;
3. deep lamina of the proper fascia;
4. endocervical fascia;
5. prevertebral fascia.
Superficial fascia .It is placed on all surface of a neck, but has a various structure in anterior and posterior portion. Anterior part of the neck Superficial fascia forms a case for platisma and together with its fibers passes on the face and below-in a subclavial region.
Proper fascia- covers anterior and posterior part of the neck. It forms cases for sternocleidomastoid and trapezoid muscles. In submandible triangle she forms case for submandibul glands. In a lateral part proper fascia connected with transversal processes cervical vertebra, owing to that it divides anatomically neck into anterior and posterior parts. And it prevent diffusion of purulent processes from a back site of neck on anterior.
Deep lamina of the proper fascia This fascia has the intermediate position in anterior part of neck between second and fourth fascias. Its form comes nearer to a trapeze and circumscribed on each side by mm.omohyoideus for which forms cases. Fascia started fro hyoid bone forms vagines to muscules- sternohyoid, omohyoid, sternothyroid, thyrohyoid. Fascia attached to an internal surface of a clavicle and sternum.
Endocervical fascia consist of two leaves-parietal and visceral. Visceral covers organs of the neck-pharynx, larynx, esophagus, trachea, thyroid. Parietal forms the vagina for middle vascular-nervous fascicle.
Prevertebral fascia take the beginning from a basis of a skull, passes downwards in thoracic cavity and ends at a level of second thoracic vertebrae. It forms the closed cases for long muscles of the head and neck, besides covers a trunk of a sympathetic nerve. Fascia form vaginas for anterior, medial and posterior scalenus muscules and for lateral vascular-nervous fascicle.
Spaces between fascias filled up by the fat.
Interfascial Spaces:
1. Spatium interaponeuroticum suprasternale; This space is posed above jugular incision of the sternum between 1 and 3 fascia. On each side it is opened and connected with vagine sternocleidomastoid muscule.
2. Spatium m. sternocleidomastoideus; it’s a fissure between back leaf of a vagine sternocleidomastoid muscule and muscle itself which filled up by friable fatty tissue.
3. Saccus ceccus retrosternocleidomastoideus; fatty space between back wall of a vagine sternocleidomastoid muscule and 3 fascia. Medially-the saccus connected with Spatium interaponeuroticum suprasternale.
4. Saccus gl. submandibulare; placed between leafs of 2 fascia.
5. Spatium vasoneurorum; space of middle triangle of the neck. Along vascular-nervous fascicle from each part there is a narrow canal which circumscribed by vagina formed by parietal leaf of 4 fascia.This space started from the basis of the skull and passes in a fat of front mediastinum.
6. Spatium previscerale; placed between parietal and visceral leafs of fourth fascia. It spreads from hyoid bone to jugular incision of the sternum. Here we can fined lymphatic nodes, fat , venous plexus of thyroid gland, in 10-12% arteria thyroid ima. Fat is free connected with a fat of anterior mediastinum.
7. Spatium retroviscerale; between visceral leaf of 4 and 5 fascias. Fatty tissues connected with a fat of posterior mediastinum.
8. Spatium prevertebrale; formed by the fissure between 5 fascia and cervical vertebrae.
9. Spatium anterscalenum; posed in a lateral triangle of the neck between 2 and 5 fascias. Together with a fat here passes subclavian vein , which separated from arteria by anterior scalenus muscules.
10. Spatium interscalenum; between anterior and medial scalenus muscules.
Carotid Arteries. The common carotid artery arises differently on the two sides: the right arises from brachiocephalic trunk behind the sternoclavicular joint; the left originates in the thorax from the arch of the aorta, passes upward and to the left and enters the neck behind the left sternoclavicular joint. This is the largest artery in the neck; and as it passes from behind the sternoclavicular joint, it runs upward and backward under cover of the anterior border of the sternocleidomastoid muscle in the direction of the mandible. When it reaches the level of the upper border of the thyroid cartilage it forms a dilation known as the carotid bulb and then divides into its 2 terminal branches: the internal and the external carotid arteries. The carotid body and the carotid sinus are 2 sensory structures which are frequently confused; they are associated with the region of the carotid bifurcation. The carotid body is a small flattened structure. It is usually found on the posteromedial side of the common carotid artery where it is held firmly in place by connective tissue. It contains numerous nerves and nerve endings and at one time was regarded as part of the chromaffin system. The carotid body represents a specialized sensory organ (vascular chemoreceptor) which responds to chemical changes in the blood and thereby affects cardiovascular output and respiration. Hypoxia and anoxia stimulate this body, resulting in an increase in blood pressure, cardiac rate and respiratory movements. On occasion, tumors arise in the carotid body, which have been referred to as “glomus” tumors. This is a misnomer, since it is not a tumor of arteriovenous origin. The removal of carotid body tumors may be extremely difficult and associated with morbidity and/or mortality. The carotid sinus is usually located at the base of the internal carotid artery and is nerve. composed of numerous and complicated sensory nerve endings. In contrast with the carotid body (chemoreceptor), the carotid sinus is a pressoreceptor. Stimulation of this sinus causes a reduction of blood pressure and a slowing of the heart rate. At times this sinus becomes unduly sensitive to pressure so that a mere turning of the head may drop the blood pressure, slow the heart and produce loss of consciousness. Denervation of the sinus may abolish this so-called carotid sinus syndrome. Throughout the course of the common carotid artery it is imbedded with the internal jugular vein and the vagus nerve, in the connective tissue that constitutes the carotid sheath. The vein lies on the lateral side of the artery and when full of blood overlaps it anteriorly. The vagus nerve lies posteriorly between the artery and the vein. Anteriorly, this artery is covered by the anterior border of the sternocleidomastoid muscle. Between the muscle and the artery in the lower part of the neck the following structures intervene: the superior belly of the omohyoid, the sternohyoid and the sternothyroid muscles. In the upper part of its course the descending ramus of the hypoglossus and the ansa hypoglossi are imbedded in the anterior wall of the sheath, and the common facial vein usually crosses the artery at its termination. Posteriorly, the artery is related to the anterior tubercles of the transverse processes of the lower 4 cervical vertebrae and the muscles that attach here, namely, the scalenus anterior and the longus capitis. It is separated from these structures by the prevertebral fascia and the sympathetic trunk. In the lower part of the neck it lies in front of the vertebral artery as it ascends to the foramen and the transverse process of the 6th cervical vertebra and in front of the inferior thyroid artery, which arches medially to the thyroid gland. On the left side the thoracic duct crosses behind the vessel and below the inferior thyroid artery. Medially, it is related to the inferior constrictor muscle of the pharynx and the thyroid gland. The lobe of the thyroid either lies medial to the artery separating it from the esophagus, the pharynx, the trachea and the larynx or forms a direct anterior relation. Laterally, it is related to the internal jugular vein and the vagus nerve.
The internal carotid artery is the larger of the 2 terminal branches of the common carotid. It is distributed to the brain and to the eye and its appendages. From its origin at the upper border of the thyroid cartilage it passes to the carotid canal of the temporal bone. It turns forward in the cavernous sinus, perforates the dura mater on the inner side of the anterior clinoid process and divides into the anterior and the middle cerebral arteries. Below the posterior belly of the digastric the artery is overlapped by the anterior border of the sternocleidomastoid and the more superficial structures; the hypoglossal nerve, the occipital artery and the common facial vein are interposed between it and the muscle. Above, the artery ascends under cover of the posterior border of the digastric and the stylohyoid and is crossed by the posterior auricular artery. It passes beneath the styloid process and the stylopharyngeus muscle. These 2 structures are placed between the artery and the parotid gland in which the external carotid artery and the posterior facial vein are imbedded. The internal carotid has no branches in the neck. It may be difficult to distinguish between the internal and the external carotid arteries.
The external carotid artery is the smaller of the 2 terminal branches of the common carotid and extends from the upper part of the thyroid cartilage to the neck of the mandible where it divides into its 2 terminal branches—the superficial temporal and the maxillary (internal) arteries. This carotid has been called “external,” not because of its location, which is really internal and superficial to the internal carotid, but because of the fact that it is distributed to parts outside of the skull. Near the angle of the jaw it is crossed by the posterior belly of the digastric and the stylohyoid muscles. Above this it is at first deep to and then enclosed by the substance of the parotid gland where it terminates opposite the neck of the mandible by dividing into its 2 terminal branches. In its short course before entering the substance of the parotid, it is applied to the inferior and the middle constrictor muscles. The vessel has 8 branches: 5 below the digastric muscle and 3 above it.The 5 branches below the digastric muscle are:
1. The superior thyroid artery, which arises from the anterior aspect of the external carotid near its origin. It passes downward and forward under cover of the omohyoid, the sternohyoid and the sternothyroid muscles, parallel with but superficial to the external laryngeal nerve. It reaches the upper pole of the thyroid gland to which it is distributed. Its branches are the infrahyoid, the superior laryngeal, the sternocleidomastoid, the cricothyroid, the isthmic, the glandular and the muscular.
2. The lingual artery arises opposite the greater cornu of the hyoid bone, makes an upward loop, disappears under cover of the hyoglossus muscle and enters the submandibular (submaxillary) region. The loop of this artery is crossed superficially by the hypoglossal nerve.
3. The facial (external maxillary) artery arises near the angle of the mandible, is directed upward and forward on the superior constrictor muscle, beneath the digastric; it continues in a groove on the deep surface of the submandibular gland to the body of the mandible and ascends to the face, anterior to the masseter muscle.
4. The ascending pharyngeal artery arises from the deep aspect of the external carotid close to its origin and continues upward, medial to the internal carotid on the side wall of the pharynx. It is usually small and supplies the pharynx, the soft palate and the meninges.
5. The occipital artery arises from the posterior aspect of the external carotid opposite the facial and continues upward and backward deep to the posterior belly of the digastric. It is crossed by the transverse part of the hypoglossal nerve at its origin, follows the posterior belly of the digastric and is in contact with the skull medial to the mastoid notch, lying deep to the process in the muscles that attach to it. It anastomoses with the deep cervical branch from the costocervical trunk and thus forms a link between the subclavian and the carotid systems.
The branches of the external carotid artery above the digastric muscle are
External and Internal Jugular Veins. The external jugular vein varies in size. It is formed below the lobule of the ear by the union of the posterior auricular vein with a branch of the posterior facial. It begins at the lower part of the parotid gland, runs almost vertically downward, crosses the sternocleidomastoid muscle obliquely, and in the angle between the clavicle and the posterior border of that muscle pierces the deep cervical fascia to which it is firmly bound; it then joins the subclavian vein. It lies upon the superficial layer of deep cervical fascia, beneath the platysma muscle, and at times may be absent or very small. It is so closely associated with the platysma that when the latter is reflected, the vein remains attached to it. If one external jugular is large the other is small; and if both are large, then the internal jugulars are correspondingly small. The external communicates with the internal jugular via a branch which turns around the anterior border of the sternocleidomastoid.
The internal jugular vein begins at the jugular foramen about 1/2 inch below the base of the skull, as a continuation of the sigmoid (transverse) sinus. It passes downward and forward through the neck and ends behind the upper border of the sternal end of the clavicle where it meets the subclavian and forms the innominate vein. It is dilated markedly at its origin, forming the superior bulb that lies in the jugular foramen and the fossa.
NERVES First anterior branches of 4 cervical nerves create cervical plexus.
Lesser Occipital supply the skin over the lateral part of the occipital region
Great Auricular it supplies the skin over the angle of the jaw, the parotid gland, the postero-inferior half of the lateral and the medial part of the auricle, and the skin over the mastoid region
Transverse cutaneous nerve supplies the skin in middle triangle
Anterior Cutaneous it supplies the region about the hyoid bone and the thyroid cartilage.
Supraclavicular nn. supplies the skin over the clavicule and shoulder.
Neck incision
• Must realize wide approach to organs or another anatomical structures
• Must realize visibility of deep landmarks inside the wound
• The postoperative wound must heal as a narrow scar
THYROID GLAND
The thyroid consists of a pair of lateral lobes which are joined across the median line by the isthmus. Each lateral lobe extends from the middle of the thyroid cartilage to the 6th tracheal ring, is pyramidal in shape with its apex upward and measures
Arteries. The arteries of the thyroid gland are 2 pairs, the superior and the inferior thyroids, and sometimes a single artery, the thyroidea ima. The superior thyroid artery is the first branch of the external carotid; it supplies infrahyoid, laryngeal and sternocleidomastoid branches in the carotid triangle. The inferior thyroid artery is a branch of the thyrocervical trunk which arises from the first part of the subclavian The thyroidea ima is a branch from the innominate or the aortic arch. It varies in size from a tiny arteriole to a vessel as large as the inferior thyroid, which it may replace.
Veins. The veins of the thyroid form a rich plexus situated in front of the gland. As they leave the gland, they form 3 main trunks in the form of superior, middle and nferior thyroid veins
Nerves. Two nerves are related to the thyroid gland: the superior and the recurrent (inferior) laryngeal. Both are branches of the vagus nerve. The superior laryngeal nerve arises from the inferior ganglion (nodosum). It divides into the internal and the external laryngeal nerves. The internal laryngeal nerve, the larger of the two branches. It is purely sensory and supplies fibers to the floor of the piriform fossa and the mucous membrane of the larynx above the vocal cord. The external laryngeal nerve. It passes deeply to the upper pole of the thyroid gland and is distributed to the cricothyroid and the inferior constrictor muscles. During ligation of the superior thyroid vessels, the external laryngeal nerve (nerve to the cricothyroid) is in danger. It may be included in the ligature, and such inclusion would cause a weakness or huskiness of the voice. However, this condition is temporary and becomes normal within a few months. The recurrent {inferior) laryngeal nerve is a structure of vital importance in thyroid surgery. Considerable variations in its position may take place so that the nerve may penetrate and traverse the gland proper, may be behind the gland, or may remain in the tracheo-esophageal groove. During thyroid surgery, when the gland is dislocated forward and medially, the nerve usually hugs the side of the trachea.
Therefore, it is important to notice on examination of the larynx whether or not a vocal cord fails to move and also to determine its position and tension. If both recurrent nerves are cut (bilateral abductor paralysis) the vocal cords become lax and cannot be tensed. This results in immediate impairment of voice but rarely causes difficulty in breathing. It is interesting to note that within 3 to 5 months the voice begins to return. This is due to a fibrosis and shrinking of the vocal cords which were previously lax. A few weeks later, the fibrotic process results in fixation of the vocal cords as they approach each other. The fibrotic contraction causes the cords to approach the midline, narrowing the glottic space to a thin slit. As a result of this, dyspnea begins to make its appearance, especially on exertion, resulting in a marked limitation of physical effort. The sympathetic nerve supply to the thyroid gland is derived from the sympathetic ganglia. The fibers from the middle and the inferior cervical ganglia reach the gland as nervous networks along the superior and the inferior thyroid arteries.
PARATHYROID GLANDS
The parathyroid glands are yellowish-brown bodies, the number and the position of which are variable. A superior and an inferior parathyroid are usually present on each side, occupying any position from the back of the pharynx to the superior mediastinum. The parathyroids lie entirely or partially within the substance of the thyroid gland, this being particularly true of the superior, which are then easily removed in thyroidectomy. The superior and the inferior parathyroid glands receive their blood supply from the corresponding thyroid vessels.
LARYNX
Cartilages of the Larynx. These are
Nerves of the Larynx. The nerve supply is derived from the vagus nerve by way of its 2 branches, the superior and the inferior (recurrent) laryngeal, both of which are mixed nerves.
Vascular Supply of the Larynx. This is derived from the superior laryngeal branch of the superior thyroid artery and the inferior laryngeal branch of the inferior thyroid artery.
Trachea
is a mobile cartilaginous and membrane tube. It commences at the lower border of the cricoid cartilage of the larynx and extends downward in the midline of the neck.Cervical part or the trachea includes 6-8 cartilages. In the thorax dividing into two main bronchi.
Vascular Supply by superior and inferior thyroid artery.
Tracheotomy (tracheostomy)
may be an elective or emergency procedure. If elective, it is usually a preliminary step to laryngectomy for malignant disease. However, if it is done as an emergency operation it is utilized where there has been sudden obstruction of the airway as a result of aspiration of a foreign body, edema of the larynx, infections and edema about the throat, or postoperative vocal cord paralysis following injury to both recurrent nerves. Distinction has been made between low and high tracheotomy, the low being below the isthmus of the thyroid and the high above it. Most authorities are of the opinion that the low operation is preferable. incsion is made extending from the lower border of the thyroid cartilage downward for about
EMERGENCY TRACHEOSTOMY
The patient is supine, the head extended on the neck and the neck flexed on the trunk by placing a sandbag under the shoulders. Along, vertical incision is made in the midline from the thyroid notch to the suprasternal notch. It is vital to stay in the midline. The cricoid is identified by palpation below the thyroid cartilage and if possible a cricoid hook is passed under its lower border and lifted vertical upwards. The deeper soft tissues are incised, again via a midline vertical incision, from the lower border of the cricoid downwards. This will be bloody because the thyroid isthmus is often divided. The vertical incision is extended into the trachea. Tracheal dilators (or any other suitable ‘spreading’ instrument) are put into the trachea. They are opened and a tracheostomy tube inserted. In an emergency, almost any other tube can be used. Once the airway has been secured in this way, haemostasis can also be secured and the patient anaesthetized if necessary. Not infrequently it is appropriate to perform a direct laryngoscopy to ascertain the cause of the upper airway obstructioecessitating the tracheostomy.
Cricothyroidotomy is an alternative to emergency tracheostomy. The trachea is entered through the cricothyroid membrane, between the inferior border of the thyroid cartilage and the superior border of the cricoid. With the patient in the position described above, a vertical skin incision is made from the superior thyroid notch to a point below the cricoid cartilage. The cricothyroid membrane is palpated and a horizontal incision made next to the upper border of the cricoid cartilage. As before, a suitable instrument is used to spread open the opening into the trachea and a tube inserted
SUBTOTAL SUBCAPSULAR RESECTION OF THYROID GLAND (STRUMECTOMY) ACCORDING TO NIKOLAEV O.V.
Indications: nodular or diffused thyreotoxic goitre and malignant tumours of thyroid gland.
The operation is suggested by O.V. Nikolaev. It is the way that external fascial capsule covers the stump of thyroid gland after resection of isthmus and anterior- lateral parts of lobes.
Patient should be placed on his back, with support under his scapulas.
Technique. After the preparation of the operative field, incision is made. It should be sited over the most prominent part of the swelling, or the level should be approximately halfway between the notch in the thyroid cartilage and the manubrium sterni.
Dermo-fascial flap is separated laterally, so that a diamond-shaped wound results. Transversal and anterior jugular veins are separated and ligated. Second and third neck fasciae are cut longitudinally between the sternohyoid and sternothyroid muscles. Both muscles are dissected transversaily – Kocher’s forceps is placed from behind them, two forceps are put on and muscles are transsected in order that thyroid gland becomes visible. 10 ml of 25% novocaine solution should be injected under the fascial capsule of each lobe. It blocks the neural plexus and makes the next step of the operation.
Partial removal of gland is begun by isthmus resection. It is performed between the two forceps. The fascial capsule is cut and moved aside backwarcs. The lower and then upper poles of one of lobes is moved into the wound. During consecutive removal of portions thyroid, gland tissue and fibrous capsule with vessels are clamped by haemostatic forceps and ligated with catgut. A small area of gland tissue, lying closely to the parathyroid glands and recurrent nerve is remained. The shape of stump of the thyroid is oval. It is covered sheets of the fascial capsule. The second lobe is moved in the same way. Suturing is commenced by the sternothyroid and sternohyoid muscles suturing by catgut. Gauze drainage is placed near the stump of glands and then the suturing of the wound is performed.
Ligations of Carotid Arteries
The indications for ligation of the common carotid artery are wounds of the carotid artery or its branches, aneurysms, angiomas, inoperable tumors of the face, the neck and the skull, hemorrhage from distal branches and at times hydrocephalus and epilepsy. Ligation of the common carotid artery can be dangerous, especially in elderly people, since it may be followed by diplopia, blindness, convulsions, coma, hemiplegia or death.The point of election is above the omohyoid muscle; however, ligation below may be necessary in injuries of the artery. Collateral circulation takes place by means of the communications between the carotids of the 2 sides, both inside and outside the skull, and by the enlargement of branches of the subclavian artery. the head is rotated toward the opposite side, and at the anterior border of the sternocleidomastoid muscle a 3-inch incision is made, the center of which is placed at the level of the cricoid cartilage. Superficial vessels are ligated; if necessary, the anterior and the external jugular veins are tied and divided. The deep fascia is severed; the sternocleidomastoid is retracted in an outward direction. The omohyoid muscle is exposed, and the carotid tubercle is felt where it lies in the angle between the sternocleidomastoid and the omohyoid. Pulsations of the artery can be felt in this angle.
Ligation of the external carotid artery is indicated for wounds, aneurysms, as a palliative measure for malignant growths, and as a preliminary step to operations in the field supplied by its branches. After ligation below the digastric muscle, the collateral circulation is brought about by the inferior with the superior thyroid arteries, the deep cervical from the costocervical with the occipital, the transverse cervical with the occipital, branches of the 2 vertebrals, and branches of the 2 internal carotids through the circle of Willis. A skin incision is made, extending for about
