Master Techniques in Otolaryngology - Head and Neck Surgery: Reconstructive Surgery, 1ed.

30. Management of the Pharyngeal Defect: The Anterolateral Thigh Flap

Donald T. Weed

INTRODUCTION

The surgical management of cancer of the hypopharynx is a challenge for both the ablative and the reconstructive head and neck surgeon. Cancers arising from this subsite in the upper aerodigestive tract are characterized by a propensity for early metastases to the cervical lymph nodes. Local growth is equally problematic, as compromise of the critical junction between the pharynx and esophageal inlet presents not only a reconstructive challenge but also the potential for underestimation of the full extent of the local disease. Preoperative imaging accurately predicts the extent of bulky disease, but submucosal spread may not be well defined by either imaging or staging endoscopy. The successful reconstructive strategy must, therefore, anticipate a range of surgical defects in order to achieve consistently good oncologic and functional outcomes.

Reconstruction of the neopharynx following laryngopharyngectomy is critical to the oncologic success of treatment, a point sometimes underestimated by the reconstructive surgeon. Successful oncologic treatment of hypopharyngeal cancer depends first and foremost on the adequacy of the surgical resection. The extent of resection, or the decision whether or not to proceed with surgical resection, should not be compromised by limitations in reconstructive options. Similarly, the reconstruction must be accomplished safely, with a goal of timely healing and recovery with limited risk for complications. Primary closure of a previously radiated pharynx may be adequate from the perspective of the anticipated luminal diameter of the reconstructed neopharynx but may place the patient at undue risk for fistula formation and the potential for additional complications, major or minor, that may accompany that fistula. Failure of a particular reconstructive technique, because of flap loss, significant fistula formation, or other related complications, may also introduce a critical delay in beginning adjuvant therapy necessary to the oncologic success of treatment.

The importance of the surgical reconstruction of hypopharyngeal defects is more obvious with regard to its impact on the functional outcomes of treatment. A successful swallowing outcome following laryngopharyngectomy depends on an adequate luminal diameter of the neopharynx. This, in turn, depends on two factors. The first is the selection of a reconstructive technique that provides for an adequate-sized neopharynx. The second is the avoidance of a fistula and its attendant risk of stricture formation when healing occurs by second intention. Successful speech rehabilitation following laryngopharyngectomy also depends on an adequate luminal diameter of the neopharynx and esophageal inlet when tracheoesophageal or esophageal speech is anticipated in the postoperative period. While a patent alimentary tract is necessary for tracheoesophageal speech, the quality of speech achieved may also be affected by the choice of cutaneous versus gastrointestinal flaps. These factors must all be considered in the planning and surgical reconstruction of the hypopharyngeal defect.

The surgical treatment of hypopharyngeal cancer depends, therefore, on a sophisticated analysis of the extent of surgical resection, the appropriate execution of this resection with clear surgical margins, and the selection of a reconstructive option that is tailored to the defect size and extent. The choice among reconstructive options is critically dependent on patient factors, such as comorbidities, and history of previous treatment, both surgical and nonsurgical, as these relate to the likelihood of achieving an uncomplicated postoperative course. The goal of the reconstructive surgeon is to insure the patient’s safe and timely return to optimal functional status. Successfully achieving this goal will not limit further cancer treatment and will maximize quality of life in patients whose overall prognosis may be poor.

Dysphagia, odynophagia, and aspiration are the most common presenting symptoms of cancer in the hypopharynx or esophageal inlet. Other symptoms include otalgia, dysphonia, dyspnea, or a mass in the neck. A history of weight loss is important as this often correlates with the local extent of disease and suggests compromised nutritional status. A thorough assessment of patient comorbidities and their impact on treatment options is critical to the development of the multidisciplinary treatment plan.

Physical examination, aided by flexible fiberoptic laryngoscopy, is generally adequate to establish a presumptive diagnosis in patients with cancer of the hypopharynx, as most lesions will be visible on fiberoptic examination. The functional status of the larynx is important to the initial treatment plan. The patient who presents in respiratory distress with bilateral vocal cord paralysis and a mass in the postcricoid hypopharynx will require a tracheostomy to establish a safe airway and is more likely to benefit from initial surgical treatment rather than a strategy focusing on organ preservation. The patient who has been previously treated for hypopharyngeal cancer with radiation or chemoradiation therapy may present with many of the same symptoms mentioned above, but the diagnostic challenge is usually greater in these patients. These symptoms may occur as a consequence of prior therapy rather than as a sign of recurrent cancer. Recurrence may be more difficult to detect on physical examination in the patient whose laryngeal and pharyngeal mucosa may be chronically edematous after previous therapy. The extent of disease recurrence is also more difficult to assess under these circumstances.

An important aspect of the examination relates to examination of the donor site. Although rare, occasionally an injury or prior surgery can preclude use of the anterolateral thigh (ALT) donor site. Similarly, a patient with gait disturbance should be carefully evaluated to determine if this donor site could further impair ambulation.

Three important factors must be considered when deciding among reconstructive options for defects of the hypopharynx and cervical esophagus. These are the extent of involvement of the posterior pharyngeal wall, the distal extent of disease and the anticipated distal extent of resection, and the involvement of cervical skin. The options for patch reconstruction of the neopharynx when an adequate amount of posterior pharyngeal mucosa remains are more varied as compared with reconstructive options for a total laryngopharyngeal defect. The distal extent of the resection is the critical determining factor when choosing a gastric pull-up rather than a regional pedicle flap or free flap alternative. Some reconstructive options are suitable for combined simultaneous use for neopharyngeal and cervical skin reconstruction, while other reconstructive options for neopharyngeal reconstruction would require an additional flap or technique for cervical skin coverage. Once these three factors have been considered with regard to the optimal choice of flap for the extent of the surgical defect, this choice must then be made in the context of other patient factors such as body habitus, donor site morbidity, and patient comorbidities.

With the exception of prior injury to the donor site, there are no contraindications to this procedure.

Imaging Studies

After history and physical examination have established a high suspicion of new or recurrent cancer in the hypopharynx, the extent of disease can accurately be assessed by high-resolution contrast-enhanced computed tomography (CT) scan. This will allow for accurate assessment of cartilage invasion, and generally reliable assessment of invasion of prevertebral musculature or encasement of the carotid artery and other factors that may establish the resectability of the cancer. Positron emission tomography combined with CT (PET–CT) is particularly useful in evaluating the local extent of disease in patients who have undergone previous radiation or chemoradiation therapy more than 3 months prior and whose physical examination is limited by diffuse posttreatment mucosal edema. PET–CT also provides for assessment of distant metastatic disease, which is important to identify in this patient population. MRI with contrast is generally reserved for those patients whose resectability is in doubt, particularly as this relates to involvement of the prevertebral fascia or involvement of the deep cervical musculature by clinically fixed lymph nodes where CT imaging does not reveal obvious muscle invasion. MRI without contrast typically can provide more diagnostic information than CT scan without contrast in patients with severe contrast allergy or poor renal function and should also be considered in these cases. Preoperative modified barium swallow (MBS) is useful in establishing baseline swallowing status in order to guide decisions regarding percutaneous gastrostomy (PEG) placement preoperatively and to assess preoperative history of aspiration as this may relate to equivocal findings on chest imaging or risk of postoperative pulmonary complications. It is also the most reliable study in evaluating invasion of the prevertebral fascia as it studies the mobility of the pharynx over the prevertebral fascia during swallowing. The MBS is not as useful as a tool to assess the extent of the disease.

Surgical Evaluation and Biopsy

Tissue biopsy to establish the presence of cancer is mandatory. Fine needle aspiration biopsy is useful to quickly and easily establish the presumptive diagnosis of cancer in patients with palpable neck disease; but false positives can occur with inflammatory neck masses. While some patients do undergo laryngopharyngectomy for complete esophageal inlet stricture or a nonfunctional larynx, or both, following chemoradiation therapy in the absence of recurrent cancer, it is critical that the difficult decision to proceed with ablative surgery in this context is made only after a thorough attempt to rule out recurrent cancer has been made. This attempt should include biopsy of the primary site.

Proceeding with ablative surgery without a positive biopsy is reasonable in some instances as long as the patient is fully apprised of the potential for no viable cancer to be found in the surgical specimen, as microscopic or multifocal disease may at times only be identified at surgical ablation rather than directed biopsy. In either case, a rigid upper endoscopy is important to accurately assess the extent of mucosal abnormality whether or not a tissue diagnosis has been established. This is especially important in assessing the extent of involvement of the posterior pharyngeal wall and the likelihood of tubed versus patch pharyngeal reconstruction. Similarly, the distal extent of cancer in the cervical esophagus must be established to determine the potential need for a gastric pull-up. When complete or near complete obstruction of the esophageal inlet precludes visualization of the distal extent of disease, the small diameter transnasal esophagoscope may sometimes traverse a tight stricture or obstruction by tumor.

When endoscopy from above cannot establish the extent of the distal disease, preoperative imaging should give a reasonably accurate assessment of whether or not tumor extends distally enough to warrant consideration of the gastric pull-up. If the concern is high but imaging is equivocal, then another option to consider is retrograde esophagoscopy via a gastrostomy tube. Placement of a gastrostomy tube will be necessary in these patients preoperatively as their dysphagia will be severe and their nutritional status compromised. A PEG in place does not preclude the ability to subsequently perform a gastric pull-up if necessary.

Patient Assessment for Reconstruction

Once the defect has been assessed as described above and is limited to a mucosal defect above the thoracic inlet with or without associated cutaneous involvement, patient factors must be evaluated to determine their suitability for ALT flap reconstruction. These include an assessment of the recipient site, the donor site, and the patient’s comorbidities. The status of the surrounding tissues in the neck beyond that of the surgical defect is critical in determining the patient’s suitability for free flap reconstruction. This includes the overall condition of the tissues and the local impact of previous therapies such as previous surgery and radiation therapy. This is generally evident by physical examination with regard to the suppleness of the soft tissues to manipulation, but the status of suitable donor vessels will be less evident and may require careful review of previous operative reports. Ultimately, this determination is definitively made at the time of the ablative procedure, so backup reconstructive plans need to be in place should a microvascular reconstruction be considered inadvisable based on operative findings.

Evaluation of the donor site is critically important when assessing the role of the ALT flap in hypopharyngeal reconstruction. While contraindications to ALT harvest exist, such as extensive prior trauma to the local site, these are uncommon. The patient’s body habitus and anticipated thickness of the flap is a crucial point to consider as this relates to the expected surgical defect. Preference should be given to the radial forearm free flap (RFFF) in patients with excess subcutaneous adipose tissue in the thigh and in whom a circumferential defect is anticipated. The jejunal free flap would be an alternative consideration in this case. A modestly thick ALT flap will still work well for a patch flap reconstruction. Finally, a careful assessment of comorbidities is important as this relates to safe perioperative medical management, and the patient’s suitability for the anticipated greater length of anesthesia required for most patients undergoing free flap reconstruction.

General Considerations

When possible, reconstruction of the hypopharynx and cervical esophagus with the ALT flap is performed as a two-team procedure with the tumor ablation performed by a surgical team separate from the reconstructive surgeon. This provides many advantages, most important of which is the overall shorter operative time facilitated by flap harvest performed simultaneously with the surgical resection. Equally important is the elimination of the ablative surgeon’s concern for compromising the surgical margins based on limitations of reconstructive options. This is not to say that the ablative surgeon should resect posterior pharynx or cervical esophagus with abandon, and a familiar working relationship between ablative and reconstructive surgeon is immensely helpful with regard to establishing consistent outcomes. The preoperative assessment of the extent of the anticipated defect is as important from an oncologic perspective as it is from a reconstructive perspective, and the patient will benefit from a careful assessment of this important point by both surgeons who are in direct communication with each other about their findings and surgical plans.

The primary goal of the preoperative planning period is to define the best operation for the patient while minimizing the chances of intraoperative surprises. When this coordinated evaluation is done properly with the ablative and reconstructive teams, then the harvest of the appropriate flap of appropriate size and design can be accomplished simultaneously with the tumor ablation to minimize operative time. Unexpected findings occasionally do occur intraoperatively despite the most careful preoperative planning, however, and unless sequential flap harvest following ablation is planned, then the flap should be harvested with some contingencies in mind. This generally means harvesting a skin paddle somewhat larger than required to allow for modification as necessary.

Flap Harvest

The patient is placed on the operative table in the supine position. Following induction of general endotracheal anesthesia, the bed is rotated 180 degrees with the feet facing the anesthesiologist. Tracheostomy is performed initially or at the time of laryngectomy depending upon the status of the airway preoperatively. Paralysis is not required for flap harvest and is generally not used with dissection simultaneously occurring in the neck. Flap harvest is performed according the technique described by Prof. Fu-Chan Wei of Taiwan. The selection of which leg to use is generally guided by patient preference, as the harvest site is sufficiently distant from the resection site such that either leg can be used for simultaneous flap harvest. A bump is sometimes placed under the ipsilateral hip but is usually not necessary. The skin paddle is centered on a line drawn from the anterior superior iliac spine to the lateral aspect of the patella. This line approximates the location of the intermuscular septum between the rectus femoris and vastus lateralis muscles. The center point between the anterior superior iliac spine and the superior aspect of the lateral patella is marked as a means of localizing the majority of skin perforators. As described by Mardini et al., a circle with a 3-cm diameter is drawn from this center point, localizing the majority of cutaneous perforators in the distal posterior quadrant of this circle (Fig. 30.1). The skin paddle is drawn to incorporate this entire circle, erring on centering the skin paddle more on this distal posterior quadrant of the circle rather than the line approximating the intermuscular septum per se. A Doppler probe can be used to localize skin perforators both within or near this circle, or cephalad or caudad to it, with the skin paddle modified to incorporate at least two perforators if possible. Due to the occasional difficulty encountered in localizing skin perforators with the Doppler probe, this circle as described is always incorporated in the skin paddle near its center point.

FIGURE 30.1 A line is drawn from the anterior superior iliac spine to the lateral aspect of the superior border of the patella. This line is bisected, and at this central point, a circle is drawn with 6-cm circumference. The skin paddle is designed to incorporate this circle, with the posterior–inferior quadrant most reliably harboring the cutaneous perforators. The skin paddle is then drawn to include sufficient skin for reconstruction of the defect while tapering the ends to facilitate closure of the donor site.

Determination of the appropriate size skin paddle is based on standard factors consistent with every pharyngoesophageal defect, as well as factors specific to the individual defect as assessed by the preoperative surgical plan. One of the main advantages of the ALT flap is that it provides the reconstructive surgeon with the ability to reconstruct total pharyngeal defects in tubed fashion as well as on-lay patch reconstruction of partial pharyngeal defects. Even if the preoperative assessment suggests that a significant (>2 cm) strip of posterior pharyngeal mucosa can be preserved, it is prudent to harvest a skin paddle of at least 9 cm in diameter. This is done in the event that assessment of the margins dictates sacrifice of the remaining posterior pharyngeal strip thought initially to be clear of tumor or if the remaining posterior pharyngeal strip appears to have insufficient vascularity to maintain a dual vertical suture line. Mucosal strips narrower than 2 cm will ultimately have two mucocutaneous suture lines running parallel to each other 1 cm or less apart, and the benefit of preserving this narrow strip in comparison to a single suture line in an appropriately vascularized cutaneous skin paddle is controversial. The mucosal strip is more frequently discarded in the previously irradiated patient as compared with nonirradiated mucosa. Even a narrow strip of mucosa is not discarded until the flap is determined to be well vascularized in the unlikely necessity of using an alternative reconstructive technique at the same operative setting.

If a pectoralis major myocutaneous (PMM) flap is chosen, then depending upon its thickness the preservation of this mucosal strip may have greater benefit. The 9-cm width is selected to ensure a neopharyngeal tube diameter of nearly 3 cm. A 9.4-cm wide skin paddle will create a 3-cm diameter tube when folded on itself, and this approximate width is also standardized between all patients. If a posterior strip of pharyngeal mucosa is successfully preserved, then the flap can be narrowed after harvest to avoid redundancy. The length of the skin paddle harvested is dependent on the location of perforators identified outside of the central circle and the need for additional skin for cervical skin reconstruction. A longer flap will allow for creation of an external skin paddle based either on a localizable skin perforator or by virtue of deepithelializing a portion of the skin paddle to enable the distal skin paddle to be folded and oriented externally. This may require horizontal rather than vertical flap inset (see Flap Inset). A horizontally inset flap will likely require a greater width to accommodate the vertical length of the defect and may not be suitable for defects including significant amounts of cervical esophagus.

Once the skin paddle is marked, the leg is circumferentially prepped and draped. The flap is harvested with loupe magnification (3.5×) in the subfascial plane. Incision is first made the length of the medial aspect of the skin paddle, subsequently incising the rectus femoris fascia on a line paralleling the skin incision (Fig. 30.2). A subfascial plane is elevated laterally to expose the intermuscular septum between rectus femoris and vastus lateralis. Regardless of the preincision localization of cutaneous perforators by Doppler probe, the elevation of the skin paddle off of the rectus femoris muscle is performed carefully to localize the cutaneous perforator(s) either within the intermuscular septum or traversing the vastus lateralis muscle. In either case, the rectus femoris muscle is widely exposed and then retracted medially to expose the primary vascular pedicle of the flap, the descending branch of the lateral circumflex femoral artery (LCFA). In this fashion, the cutaneous perforators will be localized along with the LCFA. The lateral aspect of the skin paddle is incised and elevated in a subfascial plane off of the vastus lateralis muscle and then dissection of the cutaneous perforators is performed. If these traverse the muscle, the muscle fibers anterior or medial to these perforators are elevated with a fine clamp and divided. An irrigating bipolar cautery allows for control of hemostasis with limited heat transfer to the delicate perforators. Larger muscular perforators are divided between small Ligaclips. This technique allows for elevation of the skin paddle with minimal additional bulk, a circumstance generally preferable for hypopharyngeal defect reconstruction, particularly if a tubed skin paddle is anticipated. Alternatively, a segment of vastus lateralis muscle may be harvested that incorporates a significant component of the muscle between the perforators or beyond if greater bulk is required or if vascular muscle for cervical vessel coverage is desired. This vascularized muscle may also be skin grafted for external coverage in carefully selected cases.

FIGURE 30.2 A. A 9 × 20−cm skin paddle has been elevated and replaced in its normal position on the leg. Note the thickness of the subcutaneous fat in this mildly obese patient. This represents the upper limit of ideal thickness for a tubed skin paddle. B. The undersurface of the flap is shown with a small cuff of vastus lateralis muscle elevated with the cutaneous perforator (small arrow) leaving the majority of the vastus lateralis undisturbed (largearrow) Minimizing the amount of muscle harvested with the flap is especially important in a more obese individual with a thick layer of subcutaneous fat. C. Large arrow shows the vascular pedicle with the small arrow showing a dominant single cutaneous perforator. D. The cutaneous perforator is shown at higher magnification (arrow).

Microvascular Anastomoses

Donor vessels are selected in the neck based on availability. The ALT flap vascular pedicle is of sufficient length to support anastomoses either low or high in the neck and from the contralateral side for partial pharyngeal defects if necessary. The facial artery is used in the majority of cases mobilized to its takeoff from the external carotid artery. Transverse cervical vessels are usually available in the previously dissected neck when branches of the external carotid artery may be unavailable and represent an excellent alternative to the facial vessels. Most common venous anastomoses are to the facial vein, external jugular vein, internal jugular vein, and transverse cervical vein. Two venous anastomoses are often performed with both venae comitantes of the LCFA, although these two venae comitantes often join if dissected thoroughly, allowing for a single venous anastamosis in such cases.

Flap Inset

Flap inset is relatively straightforward where a significant posterior pharyngeal strip of mucosa has been preserved. If the vascular anastomoses have been performed with the facial vessels, the proximal aspect of the skin paddle is inset in the base of the tongue and tonsil region while the distal skin is inset at the esophageal inlet. The size and shape of the skin paddle is tailored to the specific defect size after flap revascularization both to avoid redundancy of the skin paddle and to ensure that all areas of the skin paddle utilized in the mucosal reconstruction bleed appropriately. Redundancy of the skin paddle is avoided to prevent a patulous neopharynx with outpouchings of nonmucous secreting surface area that in turn will contribute to decrease bolus transit time with swallowing or possibly trap and retain portions of the bolus. The unused cutaneous portions of the skin paddle are discarded or can alternatively be harvested for split-thickness skin graft if necessary for reconstruction of the external defect. Rather than discard the full thickness of any unused portion of the skin paddle, however, the excess skin paddle is deepithelialized to preserve the well-vascularized subcutaneous adipose tissue. This can then be used as a second layer to cover the adjacent suture lines. An alternative technique described by Yu et al. is to harvest an extra width of fascia with the skin paddle such that this can be used to bolster the suture line.

Inset for a circumferential pharyngeal defect requires the creation of the alimentary tract tube by suture of the flap to itself. In most cases, this is done with the flap oriented vertically to provide sufficient length to reconstruct the pharyngeal defect without undue tension on either proximal or distal pharyngeal anastomoses. Care must be taken to approximate the circumferential size of the defect as closely as possible at the larger proximal or oropharyngeal end where an additional length of skin paddle may be preserved as an extension that both lengthens the anastomotic circumference, while also providing for inset of the flap more superiorly into the oropharynx as needed (Fig. 30.3). The opposite problem typically exists at the esophageal inlet where the normal size of the lumen is smaller, and this can be further narrowed by inset of a skin paddle with a circumferential suture line. This is offset by vertically incising the esophagus for a length of at least 1.5 cm and spatulating this mucosal edge to the 3-cm-wide cutaneous tube (Fig. 30.4). The skin paddle is closed over a Dobhoff nasogastric feeding tube if a PEG tube is not already in place, but otherwise no tube is left in the neopharyngeal lumen. Murray et al. described a small series in which no fistulae occurred and a stricture rate of 14% in 14 patients reconstructed with an ALT flap tubed over a salivary bypass tube as an alternative to consider. Any excess portions of skin paddle proximally and distally are deepithelialized, and the retained vascularized adipose tissue is used to bolster proximal and distal suture lines. Relatively short vertical segment defects can be closed with the flap inset horizontally. This may provide better orientation of the vascular pedicle in the neck and therefore reduce the risk of vessel kinking. Alternatively, this may also provide for better orientation of an external skin paddle harvested as the distal aspect of the skin paddle based either on a separate cutaneous perforator or as a distal segment of skin separated from its proximal aspect by a deepithelized strip of subcutaneous adipose tissue. An externally oriented skin paddle provides for an excellent means of monitoring the flap but is not universally used if not required for skin reconstruction.

FIGURE 30.3 A. A 9-cm-wide skin paddle has been harvested. The skin paddle is designed for a defect length of approximately 12 cm. The central portion of the flap approximates this 9 × 12−cm defect (to accommodate a neopharyngeal tube with nearly 3 cm diameter). Approximately 4 cm of additional skin are harvested proximal and distal to this central 12-cm-long segment, tapering each end of the skin paddle to facilitate closure of the donor site defect. These proximal and distal tapered ends of the skin paddle can then be tailored for the specific defect. B. In this example, the superior extent of the defect extends unilaterally into the oropharynx. This results in a defect length longer than 12 cm on one side and a superior defect circumference longer than that of the more uniform midportion or typically smaller inferior portions of the defect. This is addressed by extending the proximal skin paddle in a rounded fashion on one side to extend into the oropharynx (longarrow) while drawing a curvilinear line to the opposite side of the flap. This curvilinear line effectively lengthens the suture line (circumference) of the superior aspect of the neopharyngeal and oropharyngeal anastomosis without harvesting a wider flap with its greater donor site morbidity. The skin proximal to this curvilinear line is deepithelialized (shortarrow), preserving the subcutaneous fat to reinforce the suture line.

FIGURE 30.4 A. A triangular extension of the skin paddle is drawn to extend into the distal tapered end of the flap. The remainder of the distal tapered end skin is deepithelialized. B. A vertical incision is made in the anterior wall of the cervical esophagus. This incision is made approximately 2.5 to 3 cm in length and corresponds to the length of the legs of the triangle drawn in (A). C. The posterior wall of the esophagus is approximated to the skin paddle. D. The skin paddle triangle is inset into the anterior cervical esophagus as the distal neopharyngeal—esophageal anastomosis is completed. This spatulates the distal anastomosis, lengthening its suture line (circumference), thereby reducing likelihood of stricture.

Closure of the Donor Site

Closure of the donor site usually requires split-thickness skin grafting for defect widths of greater than 9 cm. Wide undermining of the adjacent skin edges can allow for sufficient laxity to permit primary closure in many cases where the defect width is limited to 9 cm or less. Cut edges of the vastus lateralis muscle are reapproximated with 3-0 Vicryl sutures. Closed suction drain is placed between the muscle bellies of vastus lateralis and rectus femoris to prevent seroma formation and is usually well separated from the skin graft if necessary to permit suction to be retained in the postoperative period. Early mobilization and physical therapy is encouraged in the postoperative period, although this is delayed if a bolstered skin graft is in place until the bolster is removed on postoperative day 5.

Patients are observed with surgical drains in the neck typically for 3 to 5 days. The volume and character of the drainage is closely monitored for signs of salivary leakage. If none is seen, then drains are removed when output is less than 30 mL/d. Tube feeding is initiated on postoperative day 1 but started only at a low continuous rate and advanced slowly to minimize risk of reflux. Routine stoma care is performed. Monitoring of the flap is performed with Doppler checks of the localized vascular pedicle every 1 hour while in the intensive care unit and confirmed by bedside portable color flow Doppler on postoperative day 1 to more accurately define the course and patency of the arterial and venous vascular pedicles if a monitoring skin paddle is not used.

Discharge planning begins when tube feeding has been advanced to a bolus regimen and is able to be administered by the patient and his or her family, when the patient is able to demonstrate adequate care of the tracheostomy, and if there are no clinical signs of fistula formation by postoperative day 6. Discharge typically occurs between postoperative days 6 and 9 if no postoperative complications have occurred. Follow-up is scheduled as an outpatient on postoperative days 13 to 14. Assuming no clinical signs of fistula are evident, then liquids are started by mouth under direct observation. Adequate swallowing function demonstrated at that time may allow for removal of the nasogastric feeding tube if in place. Any concern for the presence of a fistula or demonstration of difficulty with swallowing of liquids will prompt a formal MBS study to be obtained to assess overall swallowing function. Once liquids are initiated, the diet will be restricted to full liquids for 1 week, soft diet for the following week, and then a regular diet as tolerated will be initiated. For patients undergoing postoperative radiotherapy, it is essential that daily swallowing of liquids at least be maintained throughout treatment. This will help maintain patency of the neopharynx and pharyngoesophageal anastomoses through the course of therapy. Maintaining a PEG tube in these patients is still advisable to be sure they do not become dehydrated and suffer prolonged breaks in treatment as a result, but their daily swallowing must be strongly encouraged and supported by adequate pain management as needed.

Speech rehabilitation begins with the early use of an electrolarynx. Preoperative teaching by the speech therapist is important to hasten early and effective use of the device in the postoperative period. Tracheoesophageal puncture (TEP) for placement of a TEP is considered by 3 months postoperative if minimal to no dysphagia is evident. If significant dysphagia is noted, then an MBS to assess for stricture formation is performed, and consideration of dilation is entertained. If minimal dilation is necessary, then TEP can be performed at the same operative setting. Significant stricture formation may require serial dilation prior to creation of the speech fistula. These time schedules are modified as needed by the presence or absence of concomitant adjuvant therapy.

The ALT flap itself is associated with few complications; however, the reconstruction of the pharynx can be fraught with complications including fistula and wound breakdown. This occurs more commonly in the malnourished and radiated patients.

Richmon and Brumond provide a thorough summary of the various reconstructive options for hypopharyngeal defects in a recent review. The PMM flap is well suited to patch reconstruction of the neopharynx in many patients. Its advantages are its reliability, its technical ease of harvest without need for reanastomosis of its vascular supply in the neck and its versatility. The optimal patient for PMM flap reconstruction of the hypopharynx is one with a relatively thin chest wall whose neck has not received previous treatment that would impact the availability of donor vessels for microvascular reconstruction and whose preoperative risk of fistula is determined to be high based on the overall condition of the tissues in the neck after previous radiation. The published rates of stricture (0% to 16%) and fistula formation (0% to 47%) with PMM flap reconstruction are likely influenced heavily by patient selection; however, the well-vascularized pectoralis muscle that accompanies its skin paddle usually provides excellent protection of critical vascular structures in the neck should a fistula occur and is itself resistant to flap loss or vessel thrombosis in the context of a fistula. The pectoralis muscle may be skin grafted for external skin coverage if necessary. The PMM flap also provides a reliable alternative to microvascular reconstruction should free flap failure occur or in the properly selected patient with significant comorbidities as a first treatment option. The PMM flap is not well suited for the reconstruction of circumferential hypopharyngeal defects unless the chest wall is quite thin, as does occur in some patients who present with a prolonged history of dysphagia and weight loss.

The RFFF avoids many of the disadvantages of the PMM flap for hypopharyngeal reconstruction by virtue of its thin, pliable skin paddle. In the majority of cases, the RFFF can be harvested of sufficient width to reconstruct a circumferential defect provided that the distal pharyngoesophageal anastomosis remains accessible in the neck. Reported stricture (10% to 36%) and fistula (17% to 28%) rates are still significant, and the donor site morbidity of the RFFF is an important consideration. While rates of tendon exposure and limitation of hand function are low, these issues are important considerations in certain individuals whose occupation depends on precise control of hand and finger function. The donor site scar is also quite noticeable with the RFFF. Restoration of tracheoesophageal speech is reliable with the RFFF, but reconstruction of associated cervical skin defects requires an adjunctive procedure such as simultaneous PMM flap.

Gastrointestinal flaps play a significant role in reconstruction of hypopharyngeal defects. The gastric pull-up remains the procedure of choice for defects whose distal extent is beyond the thoracic inlet by providing for simultaneous complete resection of the entire esophagus as wide distal margin and a single pharyngeal anastomosis at the level of the base of the tongue. Its disadvantages are its donor site morbidity, with mortality rates reported as high as 10%. In a more recent series, Shuangba et al. reported a perioperative mortality of 2% and anastomotic leak of 9.1% in a series of 208 patients over a 20-year period. Adjunctive flaps must be considered when external coverage is required or when a significant oropharyngeal defect accompanies the hypopharyngeal defect. Free intestinal flaps are suitable for reconstruction of defects whose distal extent is above the thoracic inlet. The reported rates of stricture formation vary from 15% to 22% with the jejunal free flap, although a recent report by Sharp et al. describes 18 of 19 patients tolerating an oral diet with mean follow-up time of 4 years. Fistula rates for jejunal free flaps are similar or slightly lower than reported for RFFF. Tracheoesophageal speech has been more difficult to achieve with jejunal free flap reconstruction of the hypopharynx. Sharp et al. reports 15 of 19 patients successfully using tracheoesophageal speech, with 11 of 19 having no or mild dysphonia. Yu et al., however, reported of only 22% of 31 patients achieving fluent tracheoesophageal speech following jejunal free flap reconstruction. Other disadvantages of the free jejunal flap are its associated abdominal harvest site morbidity and the need for three intestinal anastomoses, as well as its relative size mismatch at the level of the oropharynx.

The ALT flap has gained great popularity in the reconstruction of head and neck defects by virtue of its versatility and its low donor site morbidity. A typically large skin paddle can be harvested whose thickness varies based on body habitus. This large skin paddle can be subdivided into separate skin paddles for cases in which reconstruction of a mucosal defect and external skin coverage is required based either on individual skin perforators from the vascular pedicle or by deepithelializing portions of the skin paddle whether or not separate skin perforators are identified. Vascularized muscle can also be transferred with the ALT skin paddle if additional bulk or vascular protection is required. Yu et al. have reported results of 114 patients with pharyn-goesophageal defects reconstructed with the ALT following total laryngopharyngectomy. Pharyngocutaneous fistula occurred in 9% while strictures developed in 6%. Ninety-one percent of patients tolerated an oral diet without need for feeding tube supplementation. TEP for speech rehabilitation was performed in 51 of 114 patients, with 81% of patients achieving fluent speech with secondary TEP, while 41% of patients achieving fluent speech following primary TEP. A disadvantage of the ALT flap for pharyngoesophageal reconstruction is its increased bulk in some patients. This is less disadvantageous where posterior pharyngeal wall mucosa has been preserved but may be unsuitable for circumferential defect reconstruction.

In the properly selected patient, the ALT flap provides the surgeon with the flexibility to reconstruct a variety of potential defects. These include hypopharyngeal defects where sufficient posterior pharyngeal mucosa is preserved to create an on-lay patch, total pharyngeal defects where a tubed skin paddle is required provided that sufficient cervical esophagus remains for the esophageal anastomosis to be performed in the neck, and combined mucosal and external skin defects where a single flap is preferable to two flaps. This flexibility is critical to consistently achieving acceptable short-term and long-term functional outcomes in this challenging patient population whose true extent of the disease may not be evident until the resection has been completed. While all of the reconstructive options mentioned above may provide the best alternative for any given patient, the ALT will provide the best option for the majority of patients whose hypopharyngeal and esophageal mucosal defects are above the thoracic inlet.

• Preoperative assessment of the extent of the anticipated surgical defect is critical in the reconstruction of the hypopharynx.

• Accurate assessment of the size of the defect depends on anatomic imaging such as CT and MRI, although PET–CT may be very helpful in localizing the extent of tumor in previously irradiated patients whose examination or conventional imaging may be limited by posttreatment changes.

• Staging endoscopy is an important adjunct to imaging for localization of disease at or beyond the esophageal inlet.

• The ALT provides for effective reconstruction of the defect for both partial and total pharyngeal defects and may also allow for simultaneous reconstruction of an external cervical skin defect. This versatility provides important leeway in the reconstructive plan should the ablative defect prove larger than anticipated.

• The skin paddle should be designed for a minimum width of 9 cm to create a nearly 3-cm-diameter neopharynx.

• Redundancy of the skin paddle should be avoided at flap inset in order to avoid a patulous neopharynx likely to be associated with increase transit times of the food bolus.

• Inset of the skin paddle at the esophageal inlet should include inset within a vertically oriented incision in the esophagus to broaden the esophageal inlet at the location of the distal anastomosis.

• Consider an alternate flap reconstruction if the ALT is significantly thick. This will be adequate for an on-lay patch reconstruction but inadequate for a tubed reconstruction of the total pharyngeal defect. Consider a tubed RFFF in this case.

• An accurate assessment of the distal extent of disease is imperative to avoid a circumstance where the distal defect is beyond the limit of what can be safely reconstructed with a fasciocutaneous flap. If there is significant doubt about this point, then flap harvest can be delayed until a distal mucosal incision has been made and margin cleared, with the gastric pull-up to be used instead if the resection extends beyond the cervical esophagus. This reconstructive eventuality must be prepared for with an appropriate surgical service on standby if sufficient concern for this exists.

• Standard head and neck surgical set

SUGGESTED READING

Murray DJ, Gilbert RW, Vesely MJJ, et al. Functional outcomes and donor site morbidity following circumferential pharyn-goesophageal reconstruction using an anterolateral thigh flap and salivary bypass tube. Head Neck 2007;29:147–154.

Richmon JD, Brumund KT. Reconstruction of the hypopharynx: current trends. Curr Opin Otolaryngol Head Neck Surg 2007;15:208–212.

Chan YW, Ng RW, Lun Liu LH, et al. Reconstruction of circumferential pharyngeal defects after tumour resection: reference or preference. J Plast Reconstr Aesthet Surg 2011;64(8):1022–1028.

Joo YH, Sun DI, Cho KJ, et al. Fasciocutaneous free flap reconstruction for squamous cell carcinoma of the hypopharynx. Eur Arch Otorhinolaryngol 2011;268:289–294.

Takes RP, Strojan P, Silver CE, et al. Current trends in initial management of hypopharyngeal cancer: the declining use of open surgery. Head Neck 2012;34(2):270–281