Closure Close the wound in layers over a suction drain. Postoperative care The drain is retained until there is no further drainage. Complications Intraoperative (cid:142)(cid:3) Hemorrhage. Postoperative (cid:142)(cid:3) Ha ematoma (cid:142)(cid:3) Seroma (cid:142)(cid:3) Scar. This page intentionally left blank CHAPTER 15 Head and neck surgery 646 Thyroidectomy Indications Absolute (cid:142)(cid:3) Suspicion of malignant change (cid:142) (cid:3) Compression of the trachea by a benign lesion Relative (cid:142)(cid:3) Treatment o f thyrotoxicosis (cid:142)(cid:3) Unsightly goiter Choice of operation (cid:142)(cid:3) Thyroid nodule: thyroid lobectomy (cid:142)(cid:3) Thy roid cancer: total thyroidectomy (cid:142)(cid:3) Nodular colloid goiter (with hyperthyroid ism): subtotal thyroidectomy Preoperative preparation Investigations may include indirect l aryngoscopy, thyroid function tests, serum calcium, ECG, thyroid antibodies, fine-needle as piration, and ultra- sound to exclude malignancy. Patients with thyrotoxicosis need preop- erative preparation with carbimazole, iodine, or possibly beta blockade. Informed consent m ust be obtained beforehand, and in particular it should include advice on possible change i n voice and possible hyperthy- roidism or damage to the recurrent nerve. Position of patien t Supine with neck extended at 20 \200\22325 and the table foot down. Place the head o n a padded ring with a pillow or pad beneath the shoulders. Place packs on either side of t he neck. Use a double towel as a head set. Stand on the side opposite the lobe to be remove d. Incision (Fig. 15.3A) Look for skin creases. Mark the incision beforehand with ink or a 2/0 thread pressed on the skin. Make a transverse incision near to midway between the thyro id cartilage and manubrial notch, in a crease if possible. The incision should reach the st ernomastoid on each side. Procedure (cid:142)(cid:3) Use a no. 15 blade. Deepen the incisio n through fat, platysma, and cervical fascia to expose the strap muscles. Reflect skin flaps proximally and distally. Be gin with the knife and then use gauze dissection. Stop bleeding. Insert a Joll retractor. (cid:142)(cid:3) Divide the strap muscles in the midline (Fig. 15.3B). Apply gentle tractio n to rotate the inferior pole to the opposite side. Wipe away the fascia on its undersurfac e to identify the superior para- thyroid. Now pay attention to the recurrent laryngeal nerve and the inferior thyroid artery. Move th e assistant \200\231s retractor to exert a pull laterally. Apply a small swab to the gland and exert a medial pull with the left hand to expose the fascia overlying the inferior thyr oid artery, the recurrent THYROIDECTOMY1 647 (A) Position of patient Skin creases Thyroid gland (B) Strap muscles retracted or divided Fig. 15.3 Incision for thyroidectomy and division of strap muscles CHAPTER 15 Head and neck surgery 648 laryngeal nerve, and the inferior parathyroid (Fig. 15.4). Gently divide the fascia longitu dinally to identify the nerve close to the ligament of Berry. Do not disturb the inferior p arathyroid. Simply locate it. Ligate the artery in continuity and then the inferior thyroid veins. The lobe is now free and can be removed by dividing the isthmus, dissecting the gla nd off the trachea, and oversewing the isthmus with Vicryl. In a subtotal lobectomy the gland is not dissected off the trachea. Instead, several small haemostats are applied along the lateral aspect of the gland anterior to the recurrent nerv e and the tissue anterior to the forceps is excised. The remnant is oversewn with Vicryl if possible. Total thyroidectomy Total lobectomies are performed on each side with or without radical ne ck dissection. Further operative details are given in the chapter on endocrine surgery (Cha pter 5) Closure Close in layers. Bring suction drains (one on each side) through separate stab woun ds. Close the platysma with Vicryl and the skin with clips. Postoperative care 1. Check the vocal cords postoperatively. The anesthetist usually does this (but the appearance of the cords may be misleading). 2. Ensure an adequate airway. If haematoma develops open all the layers of the wound. 3. Remove drains on day 2. Check serum calcium daily. 4. Home on day 3 \200\2235. Surgical out-patients department and thyroid function tests after 6 weeks. Complications These can be early, intermediate, or late. Early (cid:142)(cid:3) Thyrotoxic storm is rare after thyroidectomy for thyrotoxicosis but needs treatment with antithyroid drugs and beta blockade. (cid:142)(cid:3) Bleeding may be reactionary within hours of the operation and requires urgent decompression. (cid:142)(cid:3) Tracheal collapse is usually recognized by the anesthetist and requires re-intubation. (cid:142)(cid:3) Paralysis of the recurrent nerves or superior laryngeal nerve damage usually presents as a voice change if not recognized early. Intermediate (cid:142)(cid:3) Wound infection and hypocalcaemic tetany which usually occurs within a week of surgery. Always check the serum calcium preoperatively before the patient goes home. Tetany is treated by intravenous infusion of calcium and then oral administrati on of vitamin D. Late (cid:142)(cid:3) Hypothyroidism \200\224confirmed by measuring thyroxine levels. (cid: 142)(cid:3) Hypertrophy of the scar. (cid:142)(cid:3) Keloid is rare except in the dark-ski nned races. THYROIDECTOMY1 649 Inferior thyroid vein ligated Ligament of Berry Recurrent laryngeal nerve Superior parathyroid Inferior parathyroid Inferior tyroid artery Fig. 15.4 Exposure of recurrent laryngeal nerve CHAPTER 15 Head and neck surgery 650 Parathyroidectomy Indications Parathyroid adenomas, carcinoma, secondary- or tertiary-hyper parathyroidism (all four glands). Preoperative preparations Frozen section facilities should be available. The laboratory sho uld be informed. Position of patient Supine with the head on a neck ring, the neck extended, and a 20 \200\22325 downward tilt. Incision and access The same approach as for subtotal thyroidectomy is used (p646). Procedure (cid:142)(cid:3) Mobilize the thyroid gland and retract its upper and lower lobes forward. Also asssess its areolar bed. The normal parathyroid glands are difficult to ident ify but lie posterior to each of the four poles of the thyroid. Each gland is yellowish and is flattened with a small vascular pedicle. (cid:142)(cid:3) If there is an adenoma carefully remove it. If the patient has secondary- or tertiary-hyperparathyroidism, remove all four glands. (cid:142)(cid:3) Apply tissue or dissecting forceps to the gland and dissect it free by a c ombination of sharp and blunt dissection. Diathermise bleeding vessels. If you are in doubt about the nature of the tissue send biopsies for frozen section. Sometimes an adenoma can be found in the mediastinal region or in relation to the superior or inferior thyroid arter ies. Closure Layers. Clips to skin. Suction drainage. Postoperative care (cid:142)(cid:3) Observe for signs of hypocalcaemia and haematoma. (cid: 142)(cid:3) Remove the drain at 2 \200\2233 days. (cid:142)(cid:3) Repeat serum calcium dai ly to observe the trend. (cid:142)(cid:3) Most patients can have their sutures removed on d ay 4 or 5 and go home. (cid:142)(cid:3) Arrange surgical out-patients department appointment in 6 \200\2238 weeks. Complications (cid:142)(cid:3) Hemorrhage (cid:142)(cid:3) Nerve injury (cid:142)(cid:3) Unilateral recurrent laryngeal nerve injury: hoarseness (cid:142)(cid:3) B ilateral recurrent laryngeal nerve injury: stridor (cid:142)(cid:3) Superior laryngeal nerv e: change in \200\230timbre \200\231 of voice (cid:142)(cid:3) Cervical sympathetic chain: Horner \200\231s syndrome This page intentionally left blank CHAPTER 15 Head and neck surgery 652 Submandibular gland excision Anatomy The deep part of the submandibular gland lies under co ver of the medial border of the mandible, below the oral mucosa and above the mylohyoid mus cle. The superficial part is covered by deep fascia, platysma, and skin. The larger superfi cial and smaller deep lobe are joined around the posterior edge of the mylohyoid muscle. Th e submandibular duct originates from the deep surface of the deep lobe and passes forwards into the floor of the mouth where it opens as a papilla lateral to the lingual fraenum behi nd the lower incisor teeth. The facial artery and vein lie initially deep to the posterior pole and then run over the upper surface of the gland. The lingual nerve lies above the gland but anteriorly loops around the infero-lateral aspec t of the duct (Fig. 15.5) and can therefore be damaged during surgery causing tongue anesth esia. The mandibular (or marginal) division of the facial (VII) nerve can be damaged during surgery causing ipsilateral weakness of the lower lip. Patients should be warned about pos sible damage to these two nerves. Anatomically, the mandibular nerve crosses the facial artery at the lower border of the man dible. In 81% of cases the nerve lies at the level of the lower border posterior to the art ery while in the remaining 19% lies any- where up to 12mm below the mandible. For this reas on the incision should be placed in a skin crease at least 2cm below the angle of the mandi ble. The nerve lies deep to platysma, enveloped in the deep fascia overlying the gland. Ant eriorly it becomes more superficial at the angle of the mouth. Indications for removal (cid:142)(cid:3) Chronic sialadenitis (cid:142)(cid:3) Stone in sub mandibular gland or posterior duct causing obstruction (cid:142)(cid:3) Benign tumor arisin g from gland (cid:142)(cid:3) Surgical management of intractable drooling in handicapped pa tients (cid:142)(cid:3) Removal as part of radical or selective neck dissection. Equipment required (cid:142)(cid:3) Number 15 blade (cid:142)(cid:3) Bipolar diathermy (cid :142)(cid:3) Vacuum drain (cid:142)(cid:3) Vicryl ties and suture, 4/0 Prolene suture. Position Supine with head rotated to the opposite side supported by a head ring. Tilt the o perating table into a head-up position. SUBMANDIBULAR GLAND EXCISION1 653 Lingual nerve Submandibular ganglion Mylohyoid muscle Anterior Submandibular duct Submandibular gland Fig. 15.5 Removal of the submandibular gland CHAPTER 15 Head and neck surgery 654 Procedure (cid:142)(cid:3) Prepare the skin with Betadine or Chlorhexidine antiseptic. Infi ltrate lignocaine subcutaneously with adrenaline to help haemostasis. (cid:142)(cid:3) Make a transverse incision placed in a skin crease at least 20mm below the angle of the mandible. Its posterior end should not extend beyond the posterior border of the mandible (Fig. 15.6). (cid:142)(cid:3) Divide skin, subcutaneous fat, and the platysma muscle. Continue dissection obliquely upwards through the deep fascia to the inferior aspect of the gland. T hereafter dissection is continued on the capsule of the gland (except for tumors where the surrounding fascia should also be removed). This avoids damage to the mandibular branch of the facial nerve. Mobilize the gland from the anterior, posterior and inferior aspect. (cid:142)(cid:3) Identify the facial vessels deep to the posterior part of the gland and divide them. (cid:142)(cid:3) Mobilize the superficial lobe of the gland anteriorly off the mylohyoid muscle and retract the muscle forwards. At this point the lingual nerve and submandibular d uct can be identified on the deep surface of the mylohyoid muscle. The nerve is looped due to its attachment to the submandibular ganglion. (cid:142)(cid:3) Cauterize the attachments of the ganglion to the nerve and divide them. Continue mobilization of the gland from the hyoglossus muscle leaves the gland pedicl ed on the duct. Divide the duct and ligate it as far forward into the mouth as possible. (cid:142)(cid:3) Carry out careful haemostasis, suture a vacuum drain in place. Close the platysma muscle with Vicryl sutures and the skin with 4/0 Prolene. Apply an Opsite dres sing. Postoperative care Monitor blood loss in the drain. This can usually be removed the follow- ing morning and the patient should be discharged 3 \200\2234 hours later after checking th at a haematoma has not developed. Complications Intraoperative (cid:142)(cid:3) Arterial he morrhage if proximal end of facial artery not properly ligated (cid:142)(cid:3) Damage to m andibular branch of facial nerve, which is usually temporary, due to retraction injury or a ccidental diathermy (cid:142)(cid:3) Damage to lingual nerve if difficult to see, because of fibrosis following infection. Postoperative complications (cid:142)(cid:3) Haematoma \200\224this sometimes occurs after removal of drain (cid:142)(cid:3) Infection (cid:142)(cid:3) Nerve damage as previously men tioned (cid:142)(cid:3) Retained calculi in residual anterior submandibular duct. Late comp lications (cid:142)(cid:3) Unsightly scar (cid:142)(cid:3) Infection caused by calculi in a nterior duct \200\224requires intraoral excision under general anesthesia. SUBMANDIBULAR GLAND EXCISION1 655 Submandibular gland Sternomastoid muscle Incision line Fig. 15.6 Submandibular gland incision CHAPTER 15 Head and neck surgery 656 Sublingual gland excision Anatomy The sublingual gland lies anteriorly in the floor of the mouth. It is bounded by the mucosa superiorly, the mylohyoid muscle inferiorly, body of the mandible laterally and the opposite sublingual gland anteriorly. The submandibular duct li es medial to the gland as does the lingual nerve which lies in close contact with the subli ngual gland as it crosses under the submandibular duct. The gland drains mainly onto the mu cous mem- brane via small excretory ducts and sometimes directly into the subman- dibular d uct. Adjacent structures encountered in surgery are the submandibular duct and lingual nerve, an d the patient should be warned about the risk of a numb tongue or the (usually temporary) r isk of submandibular gland enlargement related to duct obstruction. Indications (cid:142)(cid:3) Ranula (cid:142)(cid:3) Tumors arising from the gland (rare). Equipment required (cid:142)(cid:3) Number 15 surgical blade (cid:142)(cid:3) Bipolar diath ermy (cid:142)(cid:3) Lacrimal duct dilator. Position Supine with the head up and supported on a head ring. Procedure With the exception of a plunging ranula, which is rare, this procedure can be ach ieved via an intra-oral approach. Infiltrate local anesthetic (2% ligno- caine with adrenal ine 1 in 80 000) around the gland to reduce blood loss. (cid:142)(cid:3) Cannulate the near by submandibular duct with a suitable lacrimal probe if technically possible. The probe will indicate the course of the duct and helps to locate the position of the lingual nerve. (cid:142)(cid:3) Make a mucosal incision running on the lingual side of the mandible lateral to the submandibular duct (Fig. 15.7). (cid:142)(cid:3) Expose the superior aspect of the sublingual gland. Raise medial and later al mucosal flaps and mobilize the anterior border of the gland by blunt dissection and care ful haemostasis. (cid:142)(cid:3) Use gauze pledgets and blunt dissection to mobilize the gland free of the duct from front to back. (cid:142)(cid:3) Carefully cautherise all vessels with bipolar diathermy. A branch of the lingual artery postero-medially may have to be tied off. (cid:142)(cid:3) Once the gland has been removed tack the mucosa lightly together with 3/0 Vicryl sutures. SUBLINGUAL GLAND EXCISION1 657 Postoperative care It is essential to monitor for postoperative haematoma in the floor of t he mouth which may compromise the airway. This procedure can often be done as a day case. Complications Intraoperative (cid:142)(cid:3) Arterial hemorrhage (cid:142)(cid:3) Venous h emorrhage. Postoperative (cid:142)(cid:3) Floor of mouth haematoma (cid:142)(cid:3) Lingual nerve damage (cid:142)(cid:3) Submandibular gland obstruction secondary to duct damage or oedema although in both cases this is usually temporary. Submandibular duct Incision line Sublingual fold (containing submandibular duct and sublingual gland) Lacrimal probe within submandibular duct Fig. 15.7 Sublingual gland excision CHAPTER 15 Head and neck surgery 658 Parotidectomy The most common operation on the parotid is the superficial parotidec- tomy. Superficial parotidectomy is a technically demanding procedure that requires a thorough kno wledge of facial nerve anatomy. There are a number of indications for this operation (liste d below). As a general rule, surgery for removal of a benign tumor, e.g. pleomorphic adenom a, is easier than for chronic infection where fibrosis and inflammation may make the dissec tion difficult. Anatomy The parotid gland lies in the hollow between the sternomastoid musc le and the ramus of mandible. The anterior border is adherent to the mas- seter muscle. Pos teriorly it is attached to the tragal cartilage and the external auditory meatus. Inferiorl y it is attached to the sternomastoid muscle. The upper border of the parotid gland extends to the level of the zygomatic arch. The parotid is enveloped within a dense capsule and Stenson \200\231s duct emerges from the anterior aspect to cross the superficial surface of the masseter muscle before passing thr ough the buccinator muscle to open into the mouth opposite the crown of the upper second mo lar tooth. Several important structures run through the gland. The most impor- tant structure is the f acial (VII) nerve which divides the parotid gland into the superficial and deep lobes. The nerve emerges from the skull base at the stylomastoid foramen, pierces the postero-medial p art of the gland and runs forward in the substance of the gland where usually it divides in to two main trunks. The two main trunks then divide into the five main branches known as th e temporal, zygomatic buccal, mandibular, and cervical branches (Fig. 15.8). There is consi derable variation in the pattern of the trunks and branches of this nerve. Other important structures include the external carotid artery which enters the deep part o f the gland postero-medially and divides into its two terminal branches. The superficial te mporal artery exits from the superior surface while the maxillary artery emerges from the a ntero- medial surface deep to the condylar neck of the mandible. The retro- mandibular vein lies deep to the plane of the facial nerve. Indications (cid:142)(cid:3) Chronic sialadeni tis (cid:142)(cid:3) Benign or some small malignant tumors arising within the gland (90% of tumors are benign) (cid:142)(cid:3) Sialosis (cid:142)(cid:3) Infection and pain related to Sjogren \200\231s syndrome. Specific aspects of consent (cid:142)(cid:3) Facial nerve paralysis Emphasize the risk of temporary (33%) or permanent facial weakness (<2%) after superficial parotidectomy . Inform the patient that it is common for the nerve to be functioning well immediately aft er surgery, but to develop temporary paralysis on the first postoperative day as a result o f oedema but that full recovery is expected. PAROTIDECTOMY1 659 Fig.Fig. Fig. Fig. 15.815.815.815.8 Anatomy of the right facial nerve \200\224typical patte rn CHAPTER 15 Head and neck surgery 660 (cid:142)(cid:3) Numbness of the ear This is due to division of the great auricular nerve during surgery. This may be reduced by preserving the posterior branch of the nerve. There is often long term partial or complete recovery of ear sensation. (cid:142)(cid:3) Frey \200\231s syndrome Incidence varies according to the type of parotidectomy (8% for inflammatory disease, 20% for malignant lesions). A total parotidecto my increases the risk of Frey \200\231s syndrome. The syndrome usually develops several mon ths after surgery and can be treated by Botulinum toxin. (cid:142)(cid:3) Cosmetic problems A retromandibular dent can be noticeable. The scar may heal badly, particularly the part in the neck. Equipment required (cid:142)(cid:3) Number 10 and 15 surgical blades (cid:142)(cid:3) Bipol ar diathermy (cid:142)(cid:3) Nerve stimulator (cid:142)(cid:3) A pair of magnifying loupes may help. Position Supine with head up with the neck extended and the head rotated to the opposite si de supported by a head-ring. Clean the operative area with Betadine in aqueous solution and apply drapes. Keep the eye and the corner of the mouth visible during surgery. This can be done by applying an Opsite dressing. Place a Jelonet pack in the external auditory meatus to avoid postoperative deafness caused by blood. Infiltrate local anaes- thetic (2% lignoca ine with adrenaline 1:80 000) along the skin incision to assist haemostasis. Incision Make this in the preauricular area, extend under the ear and down into the neck as shown in Fig. 15.9. Raise a skin flap and extend it to the ante- rior part of the parotid gland. Use sutures to hold the flap forward. Procedure (cid:142)(cid:3) Mobilize the gland from the sternomastoid muscle inferiorly. Ide ntify the great auricular nerve and preserve its posterior branch while dividing the anteri or branch. Separate the gland from the external auditory meatus posteriorly. Carry out diss ection on a broad front to allow maximum exposure and facilitate the finding of the facial nerve. (cid:142)(cid:3) Be patient whilst identifying the nerve trunk. Two landmarks are helpful; the first is the pointed cartilaginous part of the external auditory meatus, the nerve lies approximately 1cm deep to this point. The second is McEwan \200\231s triangle which is the angle bisecting the anterior border of the posterior belly of the digastric muscle and the plane of the tympanic plate and mandibular ramus (Fig. 15.9). PAROTIDECTOMY1 661 Zygomatic branch Stensons duct Temporal branch Zygomatic arch Buccal branch External auditory meatus Great auricular nerve Marginal mandibular branch Sternomastoid muscle Hyoid Posterior belly of digastric muscle Fig. 15.9 Anatomy of the left parotid gland CHAPTER 15 Head and neck surgery 662 (cid:142)(cid:3) Identify the nerve and confirm it using a nerve stimulator, provided that the patient is not paralyzed. Once located expose the main trunk by inserting fine art ery forceps above the nerve along its course and divide the overlying tissue with a knife o r scissors. The main trunk divides into two, approximately 1cm along. Thereafter, follow ea ch individual branch through to the front of the gland. In the case of a tumor, carefully d issect it free even if a small branch of the nerve has to be sacrificed. Attempts have been made to classify the intraglandular course of the facial nerve, the pattern of branching i s highly variable and necessitates cautious dissection to avoid inadvertent injury to anast omotic branches. (cid:142)(cid:3) It is not always necessary to remove the entire superficial lobe. For smal l benign tumors located within the lower pole of the gland a partial superficial parotidect omy is recommended. The technique is essentially the same as that for superficial parotidec tomy but only the branches of the VII nerve related to the tumor are dissected out. This al lows half of the superficial parotid gland to be retained and reduces the risk of damage to the nerve and the development of Frey \200\231s syndrome. Meticulous haemostasis will help to avoid damage to the nerve. Closure Irritate the wound and close the skin in layers using 3/0 Vicryl and 6/0 Prolene fo r the incision in front of the ear and 3/0 Vicryl and 4/0 Prolene or skin staples on the ne ck skin. A small vacuum drain should be sutured into place. The drain should not be placed directly on top of the facial nerve trunk. Postoperative care It is essential to monitor for excessive blood loss or haematoma. The su tures are removed on day seven. Complications Intraoperative (cid:142)(cid:3) Arterial or venous hemorrhage (cid:142)(cid:3 ) Difficulty locating nerve trunk. Postoperative (cid:142)(cid:3) Haematoma \200\224the pat ient should be made normotensive before closing the skin wound otherwise bleeding may occur (cid:142)(cid:3) Seroma (cid:142)(cid:3) Facial nerve damage \200\224it can be reassuring t o check facial nerve func- tion at the end with a nerve stimulator provided that the patient is not paralyzed (cid:142 )(cid:3) Salivary fistula (cid:142)(cid:3) Sensory loss over the lower half of the pinna. PAROTIDECTOMY1 663 Long-term (cid:142)(cid:3) Cosmetic problem with retromandibular dent \200\224a superiorly based sternomastoid muscle flap can be swung into this defect which may help (cid:142)(cid:3) Frey \200\231s syndrome several months later (cid:142)(cid:3) A poor scar (cid:142)(cid:3) Recurrent disease \200\224tumor may recur, a superficial parotidectomy only does not cure all patients with chronic sialadenitis. Other types of parotid surgery (cid:142)(cid:3) Total conservative parotidectomy indicated for chronic sialadenitis and deep lobe tumors. Following removal of the superficial lobe th e facial nerve is dissected free from the underlying parotid tissue and retracted with vasc ular slings. The deep lobe is usually easily mobilized although the external carotid artery and the retromandibular vein may have to be divided and tied. The deep lobe is delivered b etween or below the branches of the facial nerve. (cid:142)(cid:3) Total radical parotidectomy \200\224indicated for extensive malignant tumors with facial nerve involvement. Attempts should be made to preserve non-involved bran ches. Requires ligation of the external carotid artery. This operation can be performed in continuity with a radical neck dissection if lymph node metastases are present. (cid:142)(cid:3) Extracapsular dissection \200\224this is a specialist technique and is not the same as a lumpectomy. It does not require dissection of the facial nerve. The incidenc e of temporary facial paresis and Frey \200\231s syndrome are reduced. The evidence suggest s that this technique may increase the risk of recurrent tumor. It is most useful for super ficially placed benign tumors. CHAPTER 15 Head and neck surgery 664 Neck lump biopsy Diagnosis Preliminary investigation should include a CT and/or MRI scan. A fine needle aspiration biopsy (FNAB) with a 21 gauge needle may also give useful informati on. If squamous cell carcinoma is considered a likely or possible diagnosis, carry out an exami nation under anesthesia and examine the aerodiges- tive tract. An EUA can often include an ipsilateral tonsillectomy for biopsy and a fine needle aspiration biopsy of the neck lump. It is not unusual to find that a CT scan suggests a benign lesion, an FNAB does not reveal malignant cells, no primary tumor is found, and although the patient may have no symptoms t he lesion can turn out to be metastatic disease. Equipment needed for biopsy of a neck lump (cid:142)(cid:3) Number 10 and 15 surgical blade s (cid:142)(cid:3) Bipolar and monopolar diathermy (cid:142)(cid:3) Small vacuum drain. Position Supine with head up and neck extended with the head rotated to the opposite side s upported by a head ring. Procedure Before starting the procedure it is advisable to mark the neck carefully with a m arking pen. Outline the neck lump and then the neck should be marked with the incision line s for a radical neck dissection. For most biopsies the upper incision line for a neck disse ction can be used as the access incision for the neck lump. If the lump turns out to be mal ignant then it is easy to carry out a radical neck dissection with excision of a large area of skin around the biopsy site. (cid:142)(cid:3) Make a transverse incision within the mar ked incision line. Divide the platysma with blunt dissection directly down to the neck lump . If the lump is a mobile node then the node itself can be dissected out once the node has been exposed. (cid:142)(cid:3) Do not dissect out a larger mass but rather carry out an incisional biopsy . Maintain haemostasis and close the wound in layers with or without a vacuum drain. Remove the sutures at day seven. Postoperative care Monitor the patient for an expanding haematoma. If a surgical drain has been left in place, keep the patient in overnight. If not the patient can be discharged on the same day. NECK LUMP BIOPSY1 665 Complications Intraoperative (cid:142)(cid:3) Arterial hemorrhage (cid:142)(cid:3) Venous h emorrhage (cid:142)(cid:3) Accidental damage to a nerve, e.g. mandibular branch of facial n erve, accessory nerve. Postoperative (cid:142)(cid:3) Haematoma (cid:142)(cid:3) Infection (cid:142)(cid:3) Atypic al facial pain. CHAPTER 15 Head and neck surgery 666 Neck dissection A neck dissection is an operation carried out for the purpose of remov- ing the lymph nodes of the neck en bloc as part of the treatment of malignant disease in the h ead and neck region. Cervical lymph nodes are divided into a number of levels (Fig. 15.10). (cid:142)(cid:3) Level I Submandibular triangle (cid:142)(cid:3) Level II Upper jugular no des (cid:142)(cid:3) Level III Middle jugular nodes (cid:142)(cid:3) Level IV Lower jugular nodes (cid:142)(cid:3) Level V Posterior triangle nodes. As a result of this classificatio n there are now a number of different types of neck dissections which can broadly be divide d into radical and selective neck dissections. A radical neck dissection involves removal of all five levels of lymph nodes in the neck wh ile a full radical neck dissection removes lymph nodes at all five levels together with the accessory nerve, the internal jugular vein and the sternomastoid muscle. If the accessory nerve is preserved then the operation is classified as a type I modified r adical neck dissection. Preservation of the accessory nerve and the internal jugular vein m akes this a type II modified neck dissection and preservation of the accessory nerve, inter nal jugular vein, and sternomastoid muscle is a type III modified radical neck dissection. Selective neck dissections are usually carried out for the purpose of sampling the cervical lymph nodes at certain levels of the neck. Usually this operation is carried out when a pa tient has a head and neck tumor when the lymph nodes of the neck are not clinically enlarge d and when no enlarged lymph nodes can be seen on a CT or MRI scan. A good example is a squamous cell carcinoma of the tongue with no clinically obvious enlarg ed lymph nodes. It is known that this tumor has a high risk of developing metastatic lymph nodes in the neck. In these circumstances a supraomohyoid neck dissection, which removes le vel I \200\223 III lymph nodes, allows examination for micro-metastases which are not clini cally apparent. The procedure limits morbidity and if the lymph nodes have micro-metastases radiotherapy can be given as adjunctive treatment with increased five year survival. Indic ations (cid:142)(cid:3) Intraoral malignant tumors. Approximately 90% are squamous cell carcinomas, 8% are malignant salivary tumors, and 2% include other lesions such as melanoma s and sarcomas. (cid:142)(cid:3) Squamous cell carcinomas and melanomas of the skin in the head and neck region (cid:142)(cid:3) Other head and neck malignant tumors, e.g. thyroid. Equipment required All instruments for a major soft tissue dissection: (cid:142)(cid:3) Number 10, 15 and 20 size blades (cid:142)(cid:3) Unipolar and bipolar diathermy (cid:142)(cid:3) Capillary slings, tissue holders (cid:142)(cid:3) Vicryl ties of various sizes, Vicryl transfixion suture. NECK DISSECTION1 667 II I III V IV Fig. 15.10 Levels of the cervical lymph nodes Incisions (cid:142)(cid:3) Two of the most commonly used are the Y-type incision (Fig. 15.1 1) and the McFee incision (Fig. 15.12). (cid:142)(cid:3) The anatomical limits of a radical neck dissection are from approxi- mately 1cm above the clavicle inferiorly. An imaginary line drawn from the mastoid process to the angle of the mandible running along the lower border of the mandible to the midline is the upper limit. The anterior border of the trapezius muscle posteriorly, with an imagin ary line running from the middle of the chin to the medial end of the clavi- cle is the ant erior limit. (cid:142)(cid:3) If a McFee incision is used then the skin should be dissected off the unde rlying platysma muscle to the limits of the dissection described previously. Procedure (cid:142)(cid:3) Carry out dissection from the lower end. Divide the platysma mus cle, sternomastoid muscle and omohyoid muscle through the lower incision. (cid:142)(cid:3) Identify the lower end of the internal jugular vein under the omohyoid muscle and tie it of f, passing an upper and lower transfixion suture through the vessel and divide it. Check th at the thoracic duct has not been damaged. If there is a chyle leak, tie it off or clip it with a ligature. Identify and carefully dissect out the carotid artery and the vagus nerve, which are deep and slightly anterior to the internal jugular vein. Lift the fat of the pos terior triangle off the prevertebral muscles and identify the phrenic nerve as it passes ve rtically across the scalenus anterior muscle. (cid:142)(cid:3) Once all of these structures have been identified, resect the posterior tr iangle contents, the sternomastoid muscle, the omohyoid muscle and the internal jugular vei n which have been detached at their lower end upwards to the top of the neck preserving the phrenic nerve, the common carotid artery and the vagus nerve (Fig. 15.13). Divide branches of the internal jugular vein and the cervical nerve roots. (cid:142)(cid:3) Divide the ste rnomastoid muscle at the top end of the neck and amputate the lower part of the parotid gla nd. Tie and divide the CHAPTER 15 Head and neck surgery 668 posterior facial vein just deep the parotid gland, carry out dissection anteriorly to inclu de removal of the submandibular gland. Locate and divide branches of the external carotid a rtery such as the facial artery, preserving the hypoglossal nerve and the lingual nerve. (cid:142)(cid:3) Secure haemostasis once the dissection has been completed. Make a check fo r a chyle leak at the lower end of the internal jugular vein. Insert two small vacuum drain s through the skin below the lower incision line. One drain should run along the anterior b order of the trapezius muscle and the other should run up the anterior part of the neck to the submandibular region. (cid:142)(cid:3) Close the incision in layers with 3/0 Vicryl and the skin with clips and activate the vacuum drains. Postoperative complications Early (cid:142)(cid:3) Bleeding. The most common complication w hich usually necessitates a return to the operating theater if severe. Carotid artery ruptu re is potentially lethal and occurs in over 2% of cases, usually at a later stage. (cid:142)(cid:3) Infection. Wound dehiscence, necrosis and infection can occur if there has been poor flap design or poor wound closure. It is more likely after previous radiotherapy . These problems are less common when the McFee incision is used. (cid:142)(cid:3) Chyle leak. This is uncommon. A small leak may resolve itself with pressur e and intermittent suction. A severe leak requires total parenteral nutrition. (cid:142)(cid:3) Cerebral or facial oedema. This is due to poor venous drainage. It is rare with a unilateral neck dissection, but happens frequently with simultanous bilateral n eck dissections. (cid:142)(cid:3) Stroke. Manipulation of the internal carotid arteries in patients with known peripheral vascular disease can cause stroke. (cid:142)(cid:3) Salivary fistulas. This occurs in 6 \200\22330% of cases. Fistulas are usu ally small and resolve with regular dressings. Occasionally a fistula has to be ex- cised. (cid:142)(cid:3) Horner \200\231s syndrome. This is caused by accidental damage to the symp athetic nerve trunk behind the carotid sheath. It causes an ipsilateral constricted pupil, ptosis and absence of sweating of the face and neck. This tends to improve spontaneously. (cid:142)(cid:3) Death. The operative mortality rate is 1%. Late (cid:142)(cid:3) Shoulder syndrome. Sacrifice of the spinal accessory nerve usually results in a drooping shoulder, pain and reduced shoulder movement, particularly abduction. Physiotherapy may be helpful. (cid:142)(cid:3) Painful dysaesthesia. Patients may get severe discomfort when their neck is touched. This is thought to be caused by traumatic neuromas on surgically divided c ervical nerves. NECK DISSECTION1 669 Fig. 15.11 Y-shaped neck incision Fig. 15.12 McFee incision Internal jugular vein Accessory nerve (divided) Digastric muscle Hypoglossal nerve Omohyoid muscle (divided) Vagus nerve Fig. 15.13 Right, radical neck dissection with McFee incision CHAPTER 15 Head and neck surgery 670 External carotid artery ligation Anatomy The common carotid artery bifurcates at the level of the upper border of the thyroid cartilage. After the bifurcation, the external carotid a rtery lies external to the carotid sheath. The artery runs deep to the posterior belly of t he digastric muscle, crosses the styloglossus and stylopharyngeus muscles and pierces the p arotid gland, where it terminates as the superfi- cial temporal artery and the maxillary ar tery at the level of the neck of the condyle of the mandible. Indications Emergency (cid:14 2)(cid:3) Uncontrollable epistaxis (cid:142)(cid:3) Penetrating neck wounds Elective (cid:1 42)(cid:3) Tumor resection (cid:142)(cid:3) Large arteriovenous malformation Equipment requ ired (cid:142)(cid:3) Number 10 and 15 blades surgical blades. (cid:142)(cid:3) Mono- and b i-polar diathermy. (cid:142)(cid:3) Vascular slings. Position Supine with the head turned t o the opposite side and the neck extended. Incision Transverse lying within a neck crease a bout 2cm below the level of the mandible, at the level of the thyroid cartilage. Procedure (cid:142)(cid:3) Divide the skin and the underlying platysma muscle with a number 10 blade and reflect the deep cervical fascia overlying the sternomastoid muscle to allow posterior retraction of the muscle. (cid:142)(cid:3) Identify the internal jugular and mobilize it and retract it posteriorly. Careful palpation of the artery will help the operator to bluntly dissect down to the vesse l and expose it. (cid:142)(cid:3) Retract the hypoglossal nerve and posterior belly of digastric muscle supe riorly (Fig. 15.14). Find the carotid bifurcation and identify the external and internal ca rotid arteries. The internal carotid artery can be identified by the vagus nerve which acco mpanies it. The external carotid artery should be identified by finding a branch such as th e superior thyroid artery. (cid:142)(cid:3) Once the external carotid artery has been identified, dissect it out and p ass a sling under the vessel. Place one or two ties around it with 1/0 Vicryl and at this p oint, check that the bleeding is controlled. If the vessel has been penetrated and cannot b e repaired then tie the artery either side of the bleeding point. Clamp the vessel between the ties, divide it and then insert transfixion sutures at either end, again using a 1/0 Vi cryl. EXTERNAL CAROTID ARTERY LIGATION1 671 Closure Close the incision in layers with a vacuum drain if necessary. Use skin clips to cl ose the skin. Postoperative care The neck is inspected for haematoma. Skin clips can be rem oved at day seven. Complications Intraoperative (cid:142)(cid:3) Arterial hemorrhage (cid:1 42)(cid:3) Venous hemorrhage caused by injury to a large vein such as the common facial or internal jugular vein (cid:142)(cid:3) Accidental ligation of internal carotid artery. The incidence of perma- nent CVA is 30 \200\22335% and death approximately 20%.