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Complications of Surgery of the Head and Neck
Symposium on Head and Neck Surgery II
Complications of Surgery of the Head and Neck Oliver H. Beahrs, M.D.
In addition to the complications such as cardiac, vascular, and pulmonary problems that arise occasionally after surgery in any anatomic part, special morbidity occurs after head and neck operations because of the complex anatomy of the region, involving so many important structures and body systems. The surgeon operating in this region must know the anatomy thoroughly, so he can distinguish one structure from another without hesitancy in the course of a procedure and avoid unintended injury. If the disease to be dealt with is suspected on clinical examination and gross inspection and the biologic behavior of the lesion is known, the surgeon can tailor the operation for optimum management of the process and not, by undertreatment or overtreatment, expose the patient to problems that might lead to complications or mortality. Of course the surgical procedures for management of disease of the head and neck must be known thoroughly too, so they can be carried out accurately and expeditiously, and therefore more safely. The mortality of head and neck surgery today is very low: for thyroidectomy and parathyroid exploration, less than 1%; for radical neck dissection alone or as part of a composite or combined operation, 1 to 3% (1% in a recent report). 2 For other types of surgery of the head and neck the mortality rate is 0 to 1%. The availability of general anesthesia with intratracheal intubation, blood transfusion, antibiotics, and the drum principle for obtaining skin grafts to cover the operative site (as mentioned by Martin3 ) is largely responsible for the significant reduction of mortality in the past 20 to 30 years. More recently, the use of suction drainage of the operative site has added to the safety of head and neck surgery. Such drainage evacuates blood, serum, and exudate and draws viable surfaces together, permitting primary healing and significantly reducing infection, loss of skin flaps, and delayed healing. These factors that have reduced mortality have also significantly reduced the morbidity of head and neck surgery. Hemorrhage Operative hemorrhage can be profuse but it need not be so. With the patient under general anesthesia and the operating table in a head-up Surgical Clinics of North America- Vol. 57, No.4, August 1977
823
824
OLIVER
H.
BEAHRS
(reverse Trendelenburg) position, the systolic pressure drops to about 60 to 70 mm Hg. Hypotensive agents may be used, but we have not found these necessary. Surgical dissection should be along anatomic planes, and blood vessels should be controlled as they are encountered. In a radical neck dissection blood loss should not amount to more than 500 ml, and even for a composite operation or bilateral simultaneous neck dissection 1,000 ml might be expected. Most patients can tolerate this loss of blood volume; and certainly with replacement by 1 or 2 units of blood no problems should develop. If by accident major venous hemorrhage should occur, it is best controlled by finger pressure until the vessel is isolated above and below the bleeding point and ligated. By approaching hemorrhage in this manner the risk of injury to other structures is lessened. Likewise, arterial hemorrhage should be controlled by pressure until the site is found. It can then be clamped. If the common or internal carotid arteries are the source of bleeding, consideration should be given to repair of these vessels rather than ligation. Interruption of these vessels results in a mortality rate of approximately 25% and central nervous system damage to about 50% of survivors. Bilateral simultaneous neck dissection can be carried out safely (2 to 5% mortality), although venous oozing on the second side may be greater than on the first. Batson1 has shown that the paravertebral system of veins has a greater cross-sectional area than that of the jugular system, so adequate vessel capacity remains for venous blood flow from the head and neck. Cyanosis of the tissue above the clavicle may be noted for 3 to 5 days, but this clears rapidly as the remaining venous channels dilate. The residual bleeding that ordinarily follows head and neck operations is best cared for by a Penrose drain or a suction drain if the wound is large. If major hemorrhage occurs postoperatively, the operative site is best exposed for control of the offending vessel. A dressing cannot apply sufficient pressure for this; and continued bleeding or the pressure itself puts the airway in jeopardy. An attempt should be made to cover the great vessels with muscle or other soft tissue if there has been loss of skin with a risk of necrosis of the flaps or if previous radiation treatment has injured the skin.
Airway Obstruction The other major cause of morbidity and mortality in head and neck surgery is airway obstruction. First, the airway may be partially or almost totally obstructed by the pathology. Second, it can become obstructed during the induction of anesthesia-and infrequently after intubation has taken place or during the operative procedure. Third, airway obstruction during the immediate postoperative period and for 3 to 5 days afterward can lead to serious complications and death. If a goiter is compressing the trachea or deviating so much as to compromise the airway, tracheostomy under local anesthesia must be considered. For a patient with an intrinsic lesion in the oropharynx or larynx that might make intratracheal intubation difficult or dangerous, a preliminary tracheostomy would be best. In any case where difficulty is expected by the anesthesiologist, the surgeon should be in the operating
SURGICAL COMPLICATIONS
825
room during induction of anesthesia. Should technical or mechanical problems arise with the airway, an emergency tracheostomy must be considered to protect the patient from anoxia, which might develop in only a few minutes. Even when intratracheal intubation is successful, the airway can be obstructed by a kinked tube, the bevel of the tube lying against the side of the trachea, or a plug of blood clot or mucus in the lumen of the tube. These problems are constantly in the mind of the anesthesiologist, but the surgeon also should be aware of them. Once a satisfactory airway has been established, few if any problems will arise intraoperatively. At the completion of the surgical procedure a prophylactic temporary tracheostomy should be considered in certain circumstances: if the operation was of a combined or composite type in which a radical neck dissection was done in continuity with removal of an intraoral lesion, or if it was a simultaneous bilateral radical neck dissection; if the trachea has been badly compressed or deviated so there is danger of collapse of the tracheal cartilages; if there has been bilateral damage to the recurrent laryngeal nerves; if it is anticipated that the patient will have difficulty in coughing and clearing the tracheobronchial tube; if there is danger of aspiration of oral secretion or fluids or foods on swallowing-and certainly if postoperative hemorrhage is a possibility. Blood can fill the airway or a hematoma can compress it by external pressure on the trachea, oropharynx, or hypopharynx. Under any circumstances in which the airway is thought possibly to be in jeopardy, it is better to err by performing a tracheostomy rather than not. Extubation should not be done until the patient shows signs of voluntary response following the operation and the anesthesia. If the airway is not satisfactory at the time the tube is removed, the airway should be evaluated critically and the tube reinserted if necessary. For the first 24 hours after any head and neck operation the airway should be observed carefully for evidence of compromise. Anatomic or functional abnormalities must be noted. Intrinsic edema must be kept in mind as a cause of obstruction. Fortunately the safety factor in the size of the trachea in the adult is such that a markedly narrowed lumen can be tolerated; but when the safety factor is used up, complete obstruction can occur quickly. In the pediatric patient the airway is small and the safety factor significantly less. Postoperatively, if the adequacy of the airway is questioned the cause should be determined and appropriate action taken to protect the patient against obstruction and its consequences.
Late Postoperative Tracheal Aspiration After the first postoperative week, when wound swelling and bleeding have largely subsided, and when the airway is adequate (with or without a tracheostomy), the patient may still be unable to swallow his saliva or liquid food. When the resection has been so extensive that the larynx cannot be covered by the epiglottis during swallowing, the condition may become permanent, and the patient then can be fed only by nasogastric tube or gastrostomy. The gastric tube may be placed through the lateral pharyngeal wall at the operation and brought out through the
826
OLIVER
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BEAHRS
skin flap, with elimination of the hazards and discomfort of an indwelling nasopharyngeal tube. Laryngectomy rarely is necessary to eliminate tracheal aspiration. Tracheal aspiration may occur after operations that do not cause an anatomic disturbance in the larynx and its adnexa. The aspirated fluid causes multiple foci of lung infection, followed by fever, cough, and debilitation. The chest roentgenogram shows little abnormality, however; and the mechanism of aspiration cannot always be detected by the patient or the observer and may escape notice. It is seen commonly in older patients in whom a physical basis for its mechanism is difficult to establish; but when tracheal aspiration occurs in patients less than 50 years old, it is usually due to perilaryngeal edema that prevents adequate glottal closure. There is no specific means of preventing this complication, because its origins are multiple. Treatment consists in feeding by nasogastric tube until the patient can swallow normally.
Air Embolism Air embolism is a hazard of head and neck surgery, but it rarely occurs. The use of general anesthesia and of the head-up position of the patient during the operation prevents air from passing into the general circulation, even though bubbles occasionally can be seen in exposed veins at the operative site. The usual effect of air entrainment during operation is cardiac arrest due to accumulation of enough air bubbles in the pulmonary artery to block the outflow of blood. Prevention can be best accomplished by clamping the veins before dividing them; this avoids entry of air during inspiration. Successful treatment consists in the immediate lowering of the head of the table and turning the patient on his left side to allow the air to rise and settle in the apex of the right ventricle. When massive air embolism has occurred and cardiac standstill results, the usual measures of cardiac resuscitation must be taken.
Pneumothorax Pneumothorax occurs occasionally as a result ofinjury to the apex of the pleural reflection at the root of the neck during neck dissections. To prevent pneumothorax, care must be taken to avoid entering the pleura in operations at this site. Treatment consists in temporarily packing the region to make it airtight and inflating the lungs to provide expansion and liberation of the trapped air. After operation, tight adhesive strapping over pads may be applied to the base of the neck. If pneumothorax is significant and symptomatic, it is necessary to insert a catheter or an S needle into the thorax and aspirate the air so the lung will reexpand.
Emphysema Although uncommon after head and neck surgery, subcutaneous or mediastinal emphysema is most likely related to an air leak beneath the skin flaps near the tracheal stoma or elsewhere along the tracheobronchial tree. When it is present, its cause should be determined and treatment directed to it.
SURGICAL COMPLICATIONS
827
Lymph and Chylous Fistulas During radical surgery of the head and neck region, many lymphatic vessels are interrupted and the normal flow of lymph is altered. Lymph accumulates in the operative site, and its accumulation causes elevation of the skin flaps and leads to delay in healing. This is another reason for adequate drainage, preferably by a suction catheter. Usually these lymphatic vessels seal off easily, and most often the extravasation decreases to a minimum within 2 to 3 days. Rarely, interruption of the right lymphatic duct in the lower neck may lead to prolonged lymphatic drainage. The opposite is true if the left duct (thoracic duct) is interrupted during surgery. This duct should be identified during the dissection in the left lower neck. Ligation of small contributory branches of the thoracic duct should not be attempted. The thoracic duct itself may arch as high as 6 em into the neck before angling downward again and entering the subclavian vein. If by intent or accident the duct is injured, repair should not be attempted because its wall is thin and friable. If there is continuity, the duct should be left alone; if continuity is interrupted, the duct should be ligated and tied off completely. Usually, no significant complication results. If the duct has been transected and the transection has not been recognized, a chylous fistula will develop. Chyle will coagulate and, if not drained, will form a mass beneath the skin flaps; it is best removed manually. Direct drainage of the duct is preferred: the operative site is opened directly over the duct; and after a tract is well established, pressure dressings can be applied to the left lower area of the neck. Often a plug of polyvinyl mesh (Marlex) or other material will be helpful. Ligation of the duct can be attempted; but it is not often successful because it endangers adjacent structures. If the patient's condition is serious enough to justify ligation, transthoracic ligation of the thoracic duct can be considered.
Facial Edema After unilateral neck dissection, swelling occurs in the lower part of the face on the side of the operation. This is due partly to the surgical trauma, but also to interruption of the lymphatic vessels that drain this site. Within a few weeks, the swelling usually disappears and the face becomes bilaterally equal and normal. The sequelae of bilateral neck dissection are different. Cyanosis might occur first because of excision of the jugular system of veins. This most often disappears within 2 or 3 days, after which edema of the face becomes apparent. Sometimes the edema is severe-even so great that the eyes cannot be opened. It is most pronounced at about 7 days after the operation, and then it subsides gradually over a period of several weeks. Usually after bilateral neck dissection the edema in the lower part of the face does not disappear completely, and the patient is left with a chipmunk-like appearance. Subsequent surgery or infection in the operative site causes an increase or recurrence of lymphedema for a period after the trauma to the tissues.
Infection With operations on the head and neck, early primary invasive wound
828
OLIVER
H.
BEAHRS
infection is infrequent. The usual type of infection becomes manifest about the fourth or fifth postoperative day. Almost always the predisposing cause is postoperative hematoma or seroma under the loosely attached skin flap. The organisms commonly found, staphylococci and streptococci, rarely delay healing. Infections are more frequent and severe when the oral cavity is entered and when the orocervical tissues have been infected previously or subjected to radiation. Most often, infection can be prevented by careful wound toilet with attention to hemostasis and maintenance of neck flaps in contact with the deep wound surface. Wound infection is treated locally by packing the infected parts of the wound or by inserting soft rubber drains and by applying compresses of physiologic saline solution at room temperature. Systemic therapy with penicillin or another broadly effective antibiotic should be started immediately. The wound should be cultured, and after the organisms have been identified and sensitivities determined, a more specifically appropriate antibiotic may be chosen.
Neurologic Complications Iatrogenic injury to nerves of the head and neck region causes many anatomic and functional complications. At times intentional sacrifice of nerves is justified by necessity for definitive resection of diseased tissue. This is warranted if the patient is to be offered a chance of cure of the disease; accidental injury is unfortunate. The anatomy of the facial nerve is constant and techniques of parotidectomy are well established, so the risk of partial or total injury to this nerve and its branches should be essentially zero. Anatmnic dissection of the nerve results in temporary paralysis of facial muscles, total or partial, in 20% of cases. In all instances return of function occurs in 3 months or less. The lingual nerve must be protected, since transection of it will result in numbness of the ipsilateral side of the tongue. Damage to the hypoglossal nerve leaves a paralysis of the same side of the tongue. The spinal accessory nerve has a long course through the neck from the jugular foramen to the trapezius muscle. Transection of this nerve, even in the posterior cervical triangle (during node biopsy), results in lameness and drooping of the shoulder in many patients. Injury to one vagus nerve in the neck causes ipsilateral vocal-cord paralysis, but no other clinical neurologic deficit. Injury to the phrenic nerve causes paralysis of the heinidiaphragm, which may be tolerated if there are no pulmonary problems; but with respiratory problems this complication can have serious consequences. Damage to the glossopharyngeal nerve leads to difficulty in swallowing. Sacrifice or resection of the superficial sensory nerves of the head and neck results in numbness of skin areas, but this usually is of small consequence. The overlap of innervation of these nerves is such that sensation will return to large areas. Gustatory sweating or the Frey syndrome follows parotidectomy and some of the neck operations. This results in sweating over the operative site and might be found in 100% of cases if tested for, but is noted clini-
829
SURGICAL·COMPLICATIONS
cally in only 20 to 30%. It most likely is due to regeneration of neural fibers of the auriculotemporal nerve into the sweat glands of the skin in the absence of salivary tissue. The effect of injury to the recurrent laryngeal nerves in thyroid and parathyroid surgery is well known and should be guarded against. If these nerves are identified anatomically at operation, iatrogenic injury should never occur. It should be obvious that the nerve anatomy of the head and neck should be completely familiar to the surgeon so that unintended nerve injury will not occur. Necrosis of Skin Flaps Loss of skin flaps over operative sites in the head and neck results in jeopardy to blood vessels and other structures, which leads to compli" cations and mortality. Care must be taken in making incisions and developing skin flaps to protect the blood supply to them. With newer techniques of radiation therapy, loss of skin flaps due to radiation necrosis is less frequent. Modern techniques of grafting skin and making rotation flaps permit coverage of operative sites; and these should be used whenever necessary. Suction drainage has aided considerably in protecting flaps and obviating infection by preventing collection of hematoma, seroma, and exudate in operative sites. CONCLUSIONS If the head and neck anatomy is well known to the surgeon, and the pathology and its biologic behavior are recognized, iatrogenic complications should not occur. Those that occur because of the definitive surgical procedure carried out in treatment of the pathologic condition can be accepted as necessary; but their seriousness can be greatly reduced by rehabilitative and reconstructive efforts.
REFERENCES 1. Batson OV: Anatomical problems concerned in the study of cerebral blood flow. Fed Proc 3:139-144, 1944 2. Beahrs OH: Factors minimizing mortality and morbidity rates in head and neck surgery. Am J Surg 126:443-451, 1973 3. Martin H: Radical surgery in cancer of the head and neck: the changing trends in treatment. Surg Clin North Am 33:329-350, 1953 Mayo Clinic Rochester, Minnesota 55901
Complications of Surgery of the Head and Neck Oliver H. Beahrs, M.D.
In addition to the complications such as cardiac, vascular, and pulmonary problems that arise occasionally after surgery in any anatomic part, special morbidity occurs after head and neck operations because of the complex anatomy of the region, involving so many important structures and body systems. The surgeon operating in this region must know the anatomy thoroughly, so he can distinguish one structure from another without hesitancy in the course of a procedure and avoid unintended injury. If the disease to be dealt with is suspected on clinical examination and gross inspection and the biologic behavior of the lesion is known, the surgeon can tailor the operation for optimum management of the process and not, by undertreatment or overtreatment, expose the patient to problems that might lead to complications or mortality. Of course the surgical procedures for management of disease of the head and neck must be known thoroughly too, so they can be carried out accurately and expeditiously, and therefore more safely. The mortality of head and neck surgery today is very low: for thyroidectomy and parathyroid exploration, less than 1%; for radical neck dissection alone or as part of a composite or combined operation, 1 to 3% (1% in a recent report). 2 For other types of surgery of the head and neck the mortality rate is 0 to 1%. The availability of general anesthesia with intratracheal intubation, blood transfusion, antibiotics, and the drum principle for obtaining skin grafts to cover the operative site (as mentioned by Martin3 ) is largely responsible for the significant reduction of mortality in the past 20 to 30 years. More recently, the use of suction drainage of the operative site has added to the safety of head and neck surgery. Such drainage evacuates blood, serum, and exudate and draws viable surfaces together, permitting primary healing and significantly reducing infection, loss of skin flaps, and delayed healing. These factors that have reduced mortality have also significantly reduced the morbidity of head and neck surgery. Hemorrhage Operative hemorrhage can be profuse but it need not be so. With the patient under general anesthesia and the operating table in a head-up Surgical Clinics of North America- Vol. 57, No.4, August 1977
823
824
OLIVER
H.
BEAHRS
(reverse Trendelenburg) position, the systolic pressure drops to about 60 to 70 mm Hg. Hypotensive agents may be used, but we have not found these necessary. Surgical dissection should be along anatomic planes, and blood vessels should be controlled as they are encountered. In a radical neck dissection blood loss should not amount to more than 500 ml, and even for a composite operation or bilateral simultaneous neck dissection 1,000 ml might be expected. Most patients can tolerate this loss of blood volume; and certainly with replacement by 1 or 2 units of blood no problems should develop. If by accident major venous hemorrhage should occur, it is best controlled by finger pressure until the vessel is isolated above and below the bleeding point and ligated. By approaching hemorrhage in this manner the risk of injury to other structures is lessened. Likewise, arterial hemorrhage should be controlled by pressure until the site is found. It can then be clamped. If the common or internal carotid arteries are the source of bleeding, consideration should be given to repair of these vessels rather than ligation. Interruption of these vessels results in a mortality rate of approximately 25% and central nervous system damage to about 50% of survivors. Bilateral simultaneous neck dissection can be carried out safely (2 to 5% mortality), although venous oozing on the second side may be greater than on the first. Batson1 has shown that the paravertebral system of veins has a greater cross-sectional area than that of the jugular system, so adequate vessel capacity remains for venous blood flow from the head and neck. Cyanosis of the tissue above the clavicle may be noted for 3 to 5 days, but this clears rapidly as the remaining venous channels dilate. The residual bleeding that ordinarily follows head and neck operations is best cared for by a Penrose drain or a suction drain if the wound is large. If major hemorrhage occurs postoperatively, the operative site is best exposed for control of the offending vessel. A dressing cannot apply sufficient pressure for this; and continued bleeding or the pressure itself puts the airway in jeopardy. An attempt should be made to cover the great vessels with muscle or other soft tissue if there has been loss of skin with a risk of necrosis of the flaps or if previous radiation treatment has injured the skin.
Airway Obstruction The other major cause of morbidity and mortality in head and neck surgery is airway obstruction. First, the airway may be partially or almost totally obstructed by the pathology. Second, it can become obstructed during the induction of anesthesia-and infrequently after intubation has taken place or during the operative procedure. Third, airway obstruction during the immediate postoperative period and for 3 to 5 days afterward can lead to serious complications and death. If a goiter is compressing the trachea or deviating so much as to compromise the airway, tracheostomy under local anesthesia must be considered. For a patient with an intrinsic lesion in the oropharynx or larynx that might make intratracheal intubation difficult or dangerous, a preliminary tracheostomy would be best. In any case where difficulty is expected by the anesthesiologist, the surgeon should be in the operating
SURGICAL COMPLICATIONS
825
room during induction of anesthesia. Should technical or mechanical problems arise with the airway, an emergency tracheostomy must be considered to protect the patient from anoxia, which might develop in only a few minutes. Even when intratracheal intubation is successful, the airway can be obstructed by a kinked tube, the bevel of the tube lying against the side of the trachea, or a plug of blood clot or mucus in the lumen of the tube. These problems are constantly in the mind of the anesthesiologist, but the surgeon also should be aware of them. Once a satisfactory airway has been established, few if any problems will arise intraoperatively. At the completion of the surgical procedure a prophylactic temporary tracheostomy should be considered in certain circumstances: if the operation was of a combined or composite type in which a radical neck dissection was done in continuity with removal of an intraoral lesion, or if it was a simultaneous bilateral radical neck dissection; if the trachea has been badly compressed or deviated so there is danger of collapse of the tracheal cartilages; if there has been bilateral damage to the recurrent laryngeal nerves; if it is anticipated that the patient will have difficulty in coughing and clearing the tracheobronchial tube; if there is danger of aspiration of oral secretion or fluids or foods on swallowing-and certainly if postoperative hemorrhage is a possibility. Blood can fill the airway or a hematoma can compress it by external pressure on the trachea, oropharynx, or hypopharynx. Under any circumstances in which the airway is thought possibly to be in jeopardy, it is better to err by performing a tracheostomy rather than not. Extubation should not be done until the patient shows signs of voluntary response following the operation and the anesthesia. If the airway is not satisfactory at the time the tube is removed, the airway should be evaluated critically and the tube reinserted if necessary. For the first 24 hours after any head and neck operation the airway should be observed carefully for evidence of compromise. Anatomic or functional abnormalities must be noted. Intrinsic edema must be kept in mind as a cause of obstruction. Fortunately the safety factor in the size of the trachea in the adult is such that a markedly narrowed lumen can be tolerated; but when the safety factor is used up, complete obstruction can occur quickly. In the pediatric patient the airway is small and the safety factor significantly less. Postoperatively, if the adequacy of the airway is questioned the cause should be determined and appropriate action taken to protect the patient against obstruction and its consequences.
Late Postoperative Tracheal Aspiration After the first postoperative week, when wound swelling and bleeding have largely subsided, and when the airway is adequate (with or without a tracheostomy), the patient may still be unable to swallow his saliva or liquid food. When the resection has been so extensive that the larynx cannot be covered by the epiglottis during swallowing, the condition may become permanent, and the patient then can be fed only by nasogastric tube or gastrostomy. The gastric tube may be placed through the lateral pharyngeal wall at the operation and brought out through the
826
OLIVER
H.
BEAHRS
skin flap, with elimination of the hazards and discomfort of an indwelling nasopharyngeal tube. Laryngectomy rarely is necessary to eliminate tracheal aspiration. Tracheal aspiration may occur after operations that do not cause an anatomic disturbance in the larynx and its adnexa. The aspirated fluid causes multiple foci of lung infection, followed by fever, cough, and debilitation. The chest roentgenogram shows little abnormality, however; and the mechanism of aspiration cannot always be detected by the patient or the observer and may escape notice. It is seen commonly in older patients in whom a physical basis for its mechanism is difficult to establish; but when tracheal aspiration occurs in patients less than 50 years old, it is usually due to perilaryngeal edema that prevents adequate glottal closure. There is no specific means of preventing this complication, because its origins are multiple. Treatment consists in feeding by nasogastric tube until the patient can swallow normally.
Air Embolism Air embolism is a hazard of head and neck surgery, but it rarely occurs. The use of general anesthesia and of the head-up position of the patient during the operation prevents air from passing into the general circulation, even though bubbles occasionally can be seen in exposed veins at the operative site. The usual effect of air entrainment during operation is cardiac arrest due to accumulation of enough air bubbles in the pulmonary artery to block the outflow of blood. Prevention can be best accomplished by clamping the veins before dividing them; this avoids entry of air during inspiration. Successful treatment consists in the immediate lowering of the head of the table and turning the patient on his left side to allow the air to rise and settle in the apex of the right ventricle. When massive air embolism has occurred and cardiac standstill results, the usual measures of cardiac resuscitation must be taken.
Pneumothorax Pneumothorax occurs occasionally as a result ofinjury to the apex of the pleural reflection at the root of the neck during neck dissections. To prevent pneumothorax, care must be taken to avoid entering the pleura in operations at this site. Treatment consists in temporarily packing the region to make it airtight and inflating the lungs to provide expansion and liberation of the trapped air. After operation, tight adhesive strapping over pads may be applied to the base of the neck. If pneumothorax is significant and symptomatic, it is necessary to insert a catheter or an S needle into the thorax and aspirate the air so the lung will reexpand.
Emphysema Although uncommon after head and neck surgery, subcutaneous or mediastinal emphysema is most likely related to an air leak beneath the skin flaps near the tracheal stoma or elsewhere along the tracheobronchial tree. When it is present, its cause should be determined and treatment directed to it.
SURGICAL COMPLICATIONS
827
Lymph and Chylous Fistulas During radical surgery of the head and neck region, many lymphatic vessels are interrupted and the normal flow of lymph is altered. Lymph accumulates in the operative site, and its accumulation causes elevation of the skin flaps and leads to delay in healing. This is another reason for adequate drainage, preferably by a suction catheter. Usually these lymphatic vessels seal off easily, and most often the extravasation decreases to a minimum within 2 to 3 days. Rarely, interruption of the right lymphatic duct in the lower neck may lead to prolonged lymphatic drainage. The opposite is true if the left duct (thoracic duct) is interrupted during surgery. This duct should be identified during the dissection in the left lower neck. Ligation of small contributory branches of the thoracic duct should not be attempted. The thoracic duct itself may arch as high as 6 em into the neck before angling downward again and entering the subclavian vein. If by intent or accident the duct is injured, repair should not be attempted because its wall is thin and friable. If there is continuity, the duct should be left alone; if continuity is interrupted, the duct should be ligated and tied off completely. Usually, no significant complication results. If the duct has been transected and the transection has not been recognized, a chylous fistula will develop. Chyle will coagulate and, if not drained, will form a mass beneath the skin flaps; it is best removed manually. Direct drainage of the duct is preferred: the operative site is opened directly over the duct; and after a tract is well established, pressure dressings can be applied to the left lower area of the neck. Often a plug of polyvinyl mesh (Marlex) or other material will be helpful. Ligation of the duct can be attempted; but it is not often successful because it endangers adjacent structures. If the patient's condition is serious enough to justify ligation, transthoracic ligation of the thoracic duct can be considered.
Facial Edema After unilateral neck dissection, swelling occurs in the lower part of the face on the side of the operation. This is due partly to the surgical trauma, but also to interruption of the lymphatic vessels that drain this site. Within a few weeks, the swelling usually disappears and the face becomes bilaterally equal and normal. The sequelae of bilateral neck dissection are different. Cyanosis might occur first because of excision of the jugular system of veins. This most often disappears within 2 or 3 days, after which edema of the face becomes apparent. Sometimes the edema is severe-even so great that the eyes cannot be opened. It is most pronounced at about 7 days after the operation, and then it subsides gradually over a period of several weeks. Usually after bilateral neck dissection the edema in the lower part of the face does not disappear completely, and the patient is left with a chipmunk-like appearance. Subsequent surgery or infection in the operative site causes an increase or recurrence of lymphedema for a period after the trauma to the tissues.
Infection With operations on the head and neck, early primary invasive wound
828
OLIVER
H.
BEAHRS
infection is infrequent. The usual type of infection becomes manifest about the fourth or fifth postoperative day. Almost always the predisposing cause is postoperative hematoma or seroma under the loosely attached skin flap. The organisms commonly found, staphylococci and streptococci, rarely delay healing. Infections are more frequent and severe when the oral cavity is entered and when the orocervical tissues have been infected previously or subjected to radiation. Most often, infection can be prevented by careful wound toilet with attention to hemostasis and maintenance of neck flaps in contact with the deep wound surface. Wound infection is treated locally by packing the infected parts of the wound or by inserting soft rubber drains and by applying compresses of physiologic saline solution at room temperature. Systemic therapy with penicillin or another broadly effective antibiotic should be started immediately. The wound should be cultured, and after the organisms have been identified and sensitivities determined, a more specifically appropriate antibiotic may be chosen.
Neurologic Complications Iatrogenic injury to nerves of the head and neck region causes many anatomic and functional complications. At times intentional sacrifice of nerves is justified by necessity for definitive resection of diseased tissue. This is warranted if the patient is to be offered a chance of cure of the disease; accidental injury is unfortunate. The anatomy of the facial nerve is constant and techniques of parotidectomy are well established, so the risk of partial or total injury to this nerve and its branches should be essentially zero. Anatmnic dissection of the nerve results in temporary paralysis of facial muscles, total or partial, in 20% of cases. In all instances return of function occurs in 3 months or less. The lingual nerve must be protected, since transection of it will result in numbness of the ipsilateral side of the tongue. Damage to the hypoglossal nerve leaves a paralysis of the same side of the tongue. The spinal accessory nerve has a long course through the neck from the jugular foramen to the trapezius muscle. Transection of this nerve, even in the posterior cervical triangle (during node biopsy), results in lameness and drooping of the shoulder in many patients. Injury to one vagus nerve in the neck causes ipsilateral vocal-cord paralysis, but no other clinical neurologic deficit. Injury to the phrenic nerve causes paralysis of the heinidiaphragm, which may be tolerated if there are no pulmonary problems; but with respiratory problems this complication can have serious consequences. Damage to the glossopharyngeal nerve leads to difficulty in swallowing. Sacrifice or resection of the superficial sensory nerves of the head and neck results in numbness of skin areas, but this usually is of small consequence. The overlap of innervation of these nerves is such that sensation will return to large areas. Gustatory sweating or the Frey syndrome follows parotidectomy and some of the neck operations. This results in sweating over the operative site and might be found in 100% of cases if tested for, but is noted clini-
829
SURGICAL·COMPLICATIONS
cally in only 20 to 30%. It most likely is due to regeneration of neural fibers of the auriculotemporal nerve into the sweat glands of the skin in the absence of salivary tissue. The effect of injury to the recurrent laryngeal nerves in thyroid and parathyroid surgery is well known and should be guarded against. If these nerves are identified anatomically at operation, iatrogenic injury should never occur. It should be obvious that the nerve anatomy of the head and neck should be completely familiar to the surgeon so that unintended nerve injury will not occur. Necrosis of Skin Flaps Loss of skin flaps over operative sites in the head and neck results in jeopardy to blood vessels and other structures, which leads to compli" cations and mortality. Care must be taken in making incisions and developing skin flaps to protect the blood supply to them. With newer techniques of radiation therapy, loss of skin flaps due to radiation necrosis is less frequent. Modern techniques of grafting skin and making rotation flaps permit coverage of operative sites; and these should be used whenever necessary. Suction drainage has aided considerably in protecting flaps and obviating infection by preventing collection of hematoma, seroma, and exudate in operative sites. CONCLUSIONS If the head and neck anatomy is well known to the surgeon, and the pathology and its biologic behavior are recognized, iatrogenic complications should not occur. Those that occur because of the definitive surgical procedure carried out in treatment of the pathologic condition can be accepted as necessary; but their seriousness can be greatly reduced by rehabilitative and reconstructive efforts.
REFERENCES 1. Batson OV: Anatomical problems concerned in the study of cerebral blood flow. Fed Proc 3:139-144, 1944 2. Beahrs OH: Factors minimizing mortality and morbidity rates in head and neck surgery. Am J Surg 126:443-451, 1973 3. Martin H: Radical surgery in cancer of the head and neck: the changing trends in treatment. Surg Clin North Am 33:329-350, 1953 Mayo Clinic Rochester, Minnesota 55901