Daniel G. Deschler
INTRODUCTION
The reconstruction of the laryngectomy–partial pharyngectomy (LPP) defect has presented one of the greatest challenges in the history of head and neck reconstruction. This considerable defect is the result of the extension of the standard laryngectomy defect to include a significant portion of the pharynx, which precludes the primary closure done after standard laryngectomy. At least 2 cm of remaining viable mucosa is acceptable for primary closure, and anything less than this requires some form of reconstruction in order to avoid the inevi-table stenosis that follows primary closure with insufficient mucosa. The more considerable defect is that of the total laryngopharyngectomy in which the entire larynx and pharynx is resected.
A review of the reconstructive efforts that have been introduced to address this challenging defect dem-onstrates the great creativity and perseverance exemplified by reconstructive surgeons over many decades. The first technique with proven success was introduced by Wookey and modified by Montgomery. This involved a staged sequence of cervical rotation flaps to achieve eventual reconstruction of a neopharyngeal conduit. Later introduction of reconstruction using regional flaps including the deltopectoral flap and the pectoralis major flap were considerable advances in the field. These were the first flaps to be used in the immediate reconstruction of major wounds in the head and neck since they brought their own robust circulation. They also had the major advantage of being outside the radiated field and therefore more reliable.
The current state of the art for reconstruction of the partial and total laryngopharyngectomy defect is the use of free tissue transfer techniques. The major options include the use of enteric flaps such as the jejunal or gastroomental flaps, as well as fasciocutaneous free flaps such as the radial forearm and anterolateral thigh flaps. These techniques have met with great success, yet clinical situations may arise in which free tissue transfer is not achievable. Therefore, familiarity with alternative methods is mandatory.
Soon after the introduction of the pectoralis major myocutaneous (PMM) flap in the late 1970s by Ariyan and Biller in separate publications, the use of the PMM flap for reconstruction following laryngopharyngectomy was described. In the early 1980s, numerous small series were reported by Schuller and Fabian demonstrating the successful use of the PMM flap in the management of the LPP defect. These publications demonstrated an acceptably low failure rate of the flap of less than 5% with a similarly low fistula rate in the 10% to 20% range. Likewise, the stenosis rates were demonstrated to be acceptable in the 20% range. This marked a significant improvement over previously described techniques. Based upon their success, free tissue transfer reconstructive methods have largely supplanted the use of the PMM flap for this defect. However, clinical situations may still arise in which the PMM flap becomes the favored option for pharyngoesophageal reconstruction.
HISTORY
Taking a detailed history is essential when considering a reconstruction using a PMM flap. The history should emphasize prior chest wall surgery and restrictive lung disease since prior chest wall surgery may interrupt the blood supply to the flap. Similarly, a patient with restrictive lung disease may not tolerate the tight chest wall closure that is often necessary after harvesting a PMM with a large skin paddle. It is also important to consider whether the patient has had a prior vascular port for administration of chemotherapy. This can cause scarring and disruption of the pectoralis tissue planes.
PHYSICAL EXAMINATION
The physical examination should include a general medical examination to assess for cardiac, pulmonary, and renal disease. Additionally, the examination should include an evaluation of the donor site to evaluate for prior chest wall surgery that might rule out the use of the pectoralis donor site. The donor site may require reconstruction with a split thickness skin graft if the defect is too extensive for primary closure. In general, the PMM flap can be used for extensive defects but defects that extend into the nasopharynx may represent a challenge for the pedicled pectoralis flap. A free flap is the best option to reach the nasopharynx.
INDICATIONS
The decision to use the PMM flap for pharyngoesophageal reconstruction is usually because of the inability to use free tissue transfer techniques. Factors precluding the use of a free flap include the failure of a previous reconstruction using free tissue transfer, a reoperation in a significantly vessel-depleted neck, no available donor sites for reconstruction due to previous surgery, or significant medical comorbidities precluding a potentially long-duration surgery, which is characteristic of certain reconstructions using free tissue transfer.
CONTRAINDICATIONS
The only absolute contraindication to PMM flap reconstruction for the pharyngoesophageal defect is previous surgery involving the pectoralis major donor site. Any skin elevations in previous procedures, which have separated the myocutaneous perforators, as well as any interventions in the subclavicular area affecting the vascular pedicle eliminate the use of this flap. Previous median sternotomy is not a contraindication as such since it does not affect the viability of the flap. Likewise, the previous use of the internal mammary artery system has no effect on flap survival. A relative contraindication is significant tissue bulk overlying the PMM, which may preclude the placement of such tissue in the neck. This can be notable in obese patients as well as women with large breasts.
PREOPERATIVE PLANNING
Surgical Technique
There are three options for pharyngoesophageal reconstruction using the PMM flap. The first is the PMM flap used as a cutaneous “patch” to complete circumferential closure of the neopharynx following a partial pharyn-gectomy with a small segment of pharynx remaining. A second option is reconstruction of a total laryngophar-yngectomy defect in which the PMM flap is tubed to create an entirely skin-lined neopharynx. The third option is the use of the flap in a 270-degree fold over fashion with attachment of the skin island to the prevertebral fascia as described by Fabian. Although myofascial flap reconstruction of the partial and total laryngopharyn-gectomy defect has been reported, the technical details of this will not be discussed.
My technique for harvesting the PMM flap for laryngopharyngeal reconstruction is a subtle modification of the standard technique. Specific subtleties for this defect are highlighted. The flap is usually elevated in a fashion such that the skin territory of the deltopectoral flap is preserved for use in a later reconstruction should this be required. A curvilinear line is drawn extending from the axilla down toward the xiphoid process. A long ellipse is then planned around this line extending from the medial edge of the nipple to the skin overlying the pectoralis muscle’s medial attachments to the sternum. The ellipse will measure approximately 15 × 7 to 8 cm in width. This will make adequate tissue available to roll into a neopharyngeal conduit without significant ten-sion. The elongated ellipse is used so that sequential closure of the chest can be done in a simplified fashion without the need for skin grafting. The large ellipse of skin can then be easily modified to the specific laryngo-pharyngectomy defect once it is delivered into the cervical region.
The procedure begins with the incision of the lateral skin ellipse and extending toward the axilla (Fig. 29.1). The incision is taken through the underlying dermis and then sloped slightly to harvest a greater amount of subcutaneous adipose tissue over the muscle. This allows a greater potential capture of perforating vessels to the skin island. The lateral chest flap is now elevated down to the level of the pectoralis major muscle and then elevated laterally until the lateral border of the PMM is identified (Fig. 29.2). At this point, the surgeon can assess whether the skin island is optimally placed. Should it be too distally placed and have a significant random component, the skin island can be readjusted more proximally to have a greater capture of perforating vessels. With the lateral border identified, the pectoralis muscle is then gently elevated with its underlying fascia in the plane superficial to the fascia of the pectoralis minor muscle. Gentle blunt dissection is done with the fingertips in this plane up toward the clavicle, allowing identification of the vascular pedicle early in the procedure. Three to four absorbable sutures are then placed in the skin subdermally and tacked loosely to the fascia of the muscle laterally to allow stabilization of the skin island (Fig. 29.2). The medial skin incision is now created through the underlying dermis and adipose tissue to the pectoralis major muscle attachments medially. The superior skin flap is elevated in the plane just deep to the fascia of the pectoralis major muscle elevating this with the corresponding skin flap of the deltopectoral flap. The superior flap elevation is done over the clavicle until the neck incision from the laryngopharyngectomy is encountered. A tunnel admitting the entire width of the hand should be created to allow the muscle to be passed easily into the cervical region.
FIGURE 29.1 The incision design for the harvest of the PMM flap. The incision for the skin paddle is designed as an ellipse centered over the pectoralis major muscle. This allows a greater potential capture of perforating vessels to the skin island. The ellipse also facilitates closure of the donor site.
FIGURE 29.2 The incision is taken through the underlying dermis and then sloped slightly to harvest a greater amount of subcutaneous adipose tissue over the muscle. This allows a greater potential capture of perforating vessels to the skin island.
At this point, similar tacking sutures are placed in the medial portion of the skin island securing it to the muscle. The tacking sutures are removed once the flap is delivered into the neck, and the skin island inset contouring is begun. There will usually be a distal segment of the large ellipse that will overlie the rectus fascia. A small square of rectus fascia overlying the lower ribcage is harvested with this distal segment of flap. This fascia will have adhesions to the pectoralis major muscle and will maintain its connection with it upon elevation. The potential use of the fascia later in the reconstruction is described.
With the skin island secured to the muscle and the vascular pedicle identified, the flap is elevated from inferiorly to superiorly off of the chest wall using electrocautery (Fig. 29.3). At the inferior level of the sternum, the muscle can be taken directly off the ribcage as it is elevated superiorly. As the first and second ribs are approached, it is important to leave a 2-cm cuff of muscle medially to preserve the perforating vessels toward the deltopectoral flap. The skin flap is then completely elevated superiorly to the clavicle. Dissection of the muscle as it approaches the clavicle is done carefully with visualization of the main pedicle of the flap to preserve its integrity. The humeral head of the pectoralis muscle must be severed to allow adequate rotation of the flap into the cervical defect, and this is done with direct visualization of the pedicle. Full mobilization of the flap will often require sacrifice of the lateral vascular pedicle, which can be done with minimal risk to the viability of the flap if there is a prominent main pedicle. The flap is then folded superiorly, and the distal rectus fascia is held with a clamp and pulled through the tunnel to deliver the flap into the cervical region. The skin island should now be facing toward the spine.
FIGURE 29.3 The pectoralis muscle is then gently elevated with its underlying fascia in the plane superficial to the fascia of the pectoralis minor muscle.
Complete hemostasis is obtained at the donor site. Specific care is then taken to insure that all of the per-forating vessels from the thorax to the muscle have been adequately addressed. Specific care is taken during elevation not to burn or injure the perichondrium and periosteum of the ribcage as this can lead to poor wound healing. The stump of the pectoralis muscle at the humeral head is now oversewn using a large suture in a running locking fashion. Two large-bore drains are placed exiting inferiorly. The skin flaps are mobilized laterally and medially to allow primary closure with the least amount of tension.
Prior to closing the donor site, the positioning of the vascular pedicle is examined as is the skin color and integrity of the skin island to confirm that there are no venous or arterial problems after transfer into the cervical region. Perforating motor nerves are severed during the elevation off the pectoralis minor muscle. There still can be significant neural elements closely approximated to the vascular pedicle, which may upon inspection have a constricting effect on the pedicle. If this is the case, these nerves can be severed using a nerve stimulator for guidance. Unlike reconstructive efforts that require rotation of the skin island to lie externally, in which these pedicle-associated nerves should always be severed, these nerves may not require direct attention during pharyngoesophageal reconstruction.
Partial Laryngopharyngectomy Defect
Using the PMM flap for partial laryngopharyngectomy defects is a straightforward endeavor. The flap is now placed into the midline cervical region overlying the proposed defect. The proximal part of the skin island, which will correspond to the lower portion of the neopharyngeal closure, is trimmed in appropriate fashion to have an adequate tension-free position. In a similar manner, the decision is made as to the appropriate length of the flap and width of the distal segment of the pectoralis skin island to fit into the defect of the base of the tongue (Fig. 29.4). Care is taken to leave the underlying rectus fascia as this will be used to reinforce closure at the base of the tongue.
FIGURE 29.4 The pectoralis muscle and skin paddle are rotated into the pharyngeal defect for the final reconstruction.
Attention is first turned to completing the closure at the lower esophageal segment taking care to contour the lower flap and allow the 270-degree closure around the esophagus. Usually, 3 cm of skin is required for this. Now 3-0 Vicryl sutures are used in an interrupted fashion to closely approximate the skin to the mucosa and submucosa of the esophagus and remaining posterior pharyngeal mucosa (Fig. 29.5). This is usually done by placing the knots on the inside with close attention to having a subdermal to submucosal approximation creating a watertight closure with good epithelial abutment. Closure of the lateral aspect of the pharyngeal remnant is now completed on the side of the pectoralis major elevation. This is done with 3-0 Vicryl or the larger 2-0 Vicryl suture in a horizontal mattress fashion to further ensure watertight closure with good mucosal and cutaneous abutment. The flap is closed up to the base of the tongue, and the distal aspect of the previously contoured ellipse of skin is now rolled medially to achieve closure at the base of the tongue. Again, it is critical that the width of the distal flap be sufficient to cover the entire base of the tongue. This usually involves the broadest width of the harvested flap. The flap is now closed to the midline tongue base using 2-0 sutures in a horizontal mattress fashion. Attention is now turned to the contralateral lateral closure, which is done as previously described. Again, all suturing is done internally under direct visualization to ensure good mucosal and skin abutment. As the contralateral side is brought up to the base of the tongue, it will now cross toward the midline. At this point, the sutures can no longer be tied intraluminally and are therefore placed in the subdermal and submucosal fashion with a large bite to achieve closure at the base of the tongue. With this completed, the large remnant of pectoralis muscle that was elevated during the initial flap harvest is now draped over the closure. Using 3-0 Vicryl sutures in horizontal mattress fashion, the muscle is secured on the contralateral side to either the prevertebral fascia or the remnant of the pharyngeal musculature (Fig. 29.5). Superiorly, muscle as well as the rectus fascia is draped over the base of the tongue supporting the closure in this fashion. The muscle is then draped and secured around the neopharyngeal closure on the side ipsilateral to the harvest.
FIGURE 29.5 The technique of wrapping the flap 270 degrees around the anterior and lateral aspects of the defect and securing it to the remaining posterior pha-ryngeal mucosa posteriorly.
The previously elevated apron flap is now draped over the wound, and in most cases, primary closure can be achieved. If there is not sufficient skin for primary closure of the neck or if such closure would have a constricting effect on the flap pedicle, a skin graft can be placed on the pectoralis major muscle. Suction drains are applied bilaterally, placed under and superior to the flap on the side of the harvest. A soft laryngectomy tube may be necessary because of the initial bulk of the flap, but this will usually not be required long term as the muscle atrophies. The laryngectomy tube should be sewn in place, and potentially constricting tracheostomy ties should not be used.
Total Laryngopharyngectomy
Two options for closure of the total laryngopharyngectomy defect using the PMM flap are available. In patients who do not have significant bulk to their PMM flap, a complete tubulation of the flap can be undertaken for the reconstruction of the neopharynx. Care must be taken in the initial elevation to have sufficient tissue to allow complete rotation of the flap upon itself. Complete tubing is usually not achievable when the flap is large and bulky. Similar to the partial pharyngectomy defect, the flap is delivered into the cervical region and then the previously harvested ellipse is contoured to fill the specific defect. The superior skin component must be wide enough to allow complete closure at the base of the tongue. The lower skin edge can be shorter at the esophageal anastomosis that is narrower. The skin island of the flap is laid over the midline with the skin edge at the perisagittal plane just lateral to the midline on the contralateral side. The muscle and rectus fascia are secured superiorly to the prevertebral fascia to limit the amount of pull inferiorly related to time and gravity. The superior contoured component of the flap is now sewn directly to the cut edge of the pharyngeal mucosa using a horizontal mattress technique taking care to take good deep bites of tissue to support this closure. The distal aspect of the flap is then secured to the esophagus inferiorly in a similar manner usually using a 3-0 suture at this level. The flap is now circumferentially rotated and inset superiorly and inferiorly (Fig. 29.6).
FIGURE 29.6 Technique for complete tubulation of the PMM for the TLP defect after securing to the posterior pharynx superiorly and the esophagus inferiorly.
The longitudinal closure of the newly formed tube is closed on the side opposite the flap harvest. This closure is done by abutting the skin island to itself with 2-0 Vicryl sutures in horizontal mattress fashion. This is done from superior to inferior for approximately 40% of the defect and then from inferior to superiorly for approximately 40% of the defect. The last component is closed with subdermal sutures to complete the closure. A size 8 to 10 Montgomery salivary bypass tube is placed in the neopharynx prior to complete closure. In a fashion similar to the partial pharyngectomy defect, the muscle harvested with the flap is now draped over the closure and reinforced to the prevertebral fascia and to the base of the tongue. Drains are similarly placed.
In the majority of cases, a complete tubulation of the pectoralis major flap to reconstruct the total laryn-gopharyngectomy defect is not achievable. The technique of wrapping the flap 270 degrees around the anterior and lateral aspects of the defect and securing it to the prevertebral fascia posteriorly provides an excellent alternative (Fig. 29.7). In this technique, the flap again is contoured to the specific defect from the previously elevated ellipse. The posterior pharyngeal mucosa is now sutured to the prevertebral fascia superiorly. Inferiorly, the posterior esophageal mucosa is likewise secured to the prevertebral fascia. The pectoralis skin island is contoured to fit in this defect with attention being placed on leaving enough skin superiorly to complete the closure at the base of the tongue. Although the early descriptions of this technique discuss placing of a skin graft over the prevertebral fascia, subsequent experience has shown this to be unnecessary. The skin island on the side ipsilateral to the flap elevation is now secured to the prevertebral fascia using 2-0 Vicryl in an interrupted or horizontal mattress fashion. Large bites of the subdermis are secured to the prevertebral fascia and tied externally. This places close abutment of the dermis to the underlying prevertebral fascia and muscle. The prevertebral fascia may be scored along the line of the proposed closure to expose the more vascular muscle. The ipsilateral closure is completed in a linear fashion. Closure of the skin to the esophageal component is now done rolling it toward the contralateral aspect side. This is likewise done at the base of the tongue. The subdermis of the flap is now secured to the prevertebral fascia on the contralateral side providing complete closure of the defect. The use of a salivary bypass is recommended. The muscle again is draped over the closure and then secured contralaterally to the prevertebral fascia. Drains are placed as described previously.
FIGURE 29.7 The technique of wrapping the flap 270 degrees around the anterior and lateral aspects of the defect and securing it to the prevertebral fascia posteriorly provides an excellent alternative when tubing is not possible.
As with the partial laryngopharyngectomy, the apron flap is closed over the neopharyngeal reconstruction. If there is insufficient tissue or pedicle constriction, then a skin graft is applied. Drains are left in place until criteria are met for removal.
POSTOPERATIVE MANAGEMENT
Tube feeds are given through a preexisting gastrostomy tube or via a nasogastric tube placed through the salivary bypass tube. Patients are kept NPO for at least 2 weeks. This may be extended if significant preexisting conditions favoring fistula formation exist. A pharyngogram is done, with the salivary bypass tube in place. If no leak is noted, then the salivary bypass is removed in the office and oral diet is begun.
COMPLICATIONS
The most common complication after PMM flap reconstruction of the laryngopharyngectomy defect is fistula formation. The series prior to the chemoradiation era reported fistula rates in the 20% range, which are higher now for salvage surgery. In the majority of cases, a fistula will be self-limited and managed with standard wound care. The salivary bypass tube is left in place to aid with management of secretions. Once the fistula has closed, an oral diet is begun.
Flap failure is rare with pectoralis flap reconstruction, and to avoid this complication, meticulous flap elevation and inspection of pedicle integrity and geometry during closure are critical. If flap failure occurs, then the contralateral PMM flap can be used. Stenosis is another common complication with the fistula being the primary risk factor. Stenosis occurs most commonly at the distal anastomosis and is best diagnosed by history and pharyngogram. Management is with judicious dilation. Excess flap bulk in the neck and its subsequent effects on stomal geometry is a common sequel of this technique rather than a complication. Time will allow muscle atrophy and relief of the functional problems related to bulk.
Donor site complications are likewise rare. Hematoma is the most common and should be addressed with expeditious drainage. After standard donor site closure, a significant depression should be present below the clavicle. If this concavity flattens, then hematoma formation is highly unlikely. Formal ligature of the humeral head of the pectoralis muscle as well as attention to the perforators from the ribcage should help to prevent hematoma. Wound dehiscence can be avoided with appropriate mobilization of the PMM flap and positioning at the time of closure. If the closure was felt to be tight, then the skin staples can be left in place for 2 weeks.
Tumor implantation at the chest donor site has been reported, but fortunately, it is an exceedingly rare occurrence.
RESULTS
The results with this technique are reliable and, in general, excellent. The donor tissue is ideal for patients who have been radiated and are at risk for fistula formation.
PEARLS
• The harvesting of a large ellipse of skin usually allows for primary closure of the donor site as well as providing sufficient tissue for the reconstruction of the pharyngectomy defect.
• Dependable and effective tracheoesophageal voice restoration is achievable after PMM flap reconstruction of the pharyngoesophageal defect.
PITFALLS
• Fistula formation is common enough in the current era to not be a surprising development for the experienced reconstructive surgeon.
INSTRUMENTS TO HAVE AVAILABLE
• Standard head and neck surgical set
SUGGESTED READING
Wookey H. The surgical treatment of carcinoma of the pharynx and upper esophagus. Surg Gynecol Obstet 1942;75:499–506. Montgomery WW. Reconstruction of the cervical esophagus. Arch Otolaryngol 1963;77:609–620.
Bakamjian VY. A two stage method for pharyngoesophageal reconstruction with a primary pectoral skin flap. Plast Reconstr Surg 1965;36:173–184.
Fabian RL. Reconstruction of the laryngopharynx and cervical esophagus. Laryngoscope 1984;94:1334–1350.
Schuller DE. Reconstructive options for pharyngoesophageal and/or cervical esophageal defects. Arch Otolaryngol 1985;111:193–197.