Reconstruction of Hypopharyngeal Defects

Introduction

The hypopharynx is a complex anatomic region that begins at the level of the hyoid and terminates at the esophageal inlet. It is adjacent to, but distinct from, the larynx and is the functional conduit that carries food from the oropharynx to the esophagus. Three anatomic subsites are included: paired pyriform sinuses, posterior pharyngeal wall, and postcricoid pharynx ( Fig. 49.1 ).

Key Operative Learning Points

• There are many reconstructive options for creating a neopharynx, and decision making depends on the following four general criteria: (1) size of the defect (laryngectomy with partial pharyngectomy, total laryngopharyngectomy, and total laryngopharyngectomy with cervical esophagectomy), (2) surgeon’s experience with regional and free tissue transfer, (3) available donor sites that will provide sufficient tissue to reconstruct the defect, and (4) donor site morbidity that may help to select among multiple tissue flaps.

• A pharyngeal leak is the primary complication that carries a risk of significant morbidity/mortality for the patient. A leak not only puts a free tissue reconstruction at risk but also leads to fistula, wound healing complications, and infection leading to possible carotid blowout. This will prolong the postoperative care and delay oral intake and rehabilitation of speech.

• Stricture resulting from an inadequate pharyngeal circumference will impact the quality of deglutition but will also predispose patients to developing a pharyngeal leak.

Preoperative Period

In preparing for reconstruction of hypopharyngeal defects, it is critical to anticipate the size of the defect and the remaining adjacent healthy tissue. With small lesions that can be removed via a transoral approach no reconstruction may be necessary, and the tissue can be left to heal by secondary intention. Unfortunately, hypopharyngeal cancer usually presents late and requires not only resection of the hypopharynx but also the larynx. This is, in part, from their late presentation. In general, tumors of the hypopharynx, more than 95% of which are squamous cell carcinoma, carry very high overall mortality rates (65% of patients die within 5 years of presentation). These cancers are characterized by submucosal spread with invasion of surrounding structures that lack barriers for spread, metastases to the neck or distant metastases at presentation, and a higher rate of synchronous second primary cancers.

Understanding the variety of surgical approaches for tumor resection can be helpful when anticipating the size of the defect required for reconstruction ( Table 49.1 ). They can generally be divided into approaches that spare the larynx and those that require a laryngectomy. Laryngeal sparing procedures include transoral endoscopic approaches to the hypopharynx, as well as open approaches that resect a portion of one or more hypopharyngeal subsites, but preserve the larynx. Examples include well-circumscribed cancers of the posterior pharyngeal wall or small cancers in the pyriform sinus that can be excised along with a portion of the aryepiglottic fold. Open approaches with partial resection of the larynx can carry higher morbidity, particularly if the patient has had prior radiation of the neck. Laryngeal-sparing open approaches include a midline pharyngotomy with or without mandibulotomy, lateral pharyngotomy, and partial resection of the larynx with partial pharyngectomy. More commonly, a laryngectomy is required for patients with advanced cancer at presentation or persistent cancer following chemoradiation. Achieving a negative margin may require partial pharyngectomy or total circumferential pharyngectomy ( Fig. 49.2 ). When the cancer extends to the cervical esophagus, a cervical or total esophagectomy is required.

There are many options when evaluating the reconstruction of a hypopharyngeal defect, and many decisions are based on the surgeon’s preference and experience. A defect-oriented approach can be helpful when deciding reconstructive options ( Table 49.2 ). The simplest reconstruction is none at all—and this can be achieved with many defects following endoscopic resection because there is a lower risk for pharyngocutaneous fistula and the wound can be left to granulate. After an open approach is used to do a partial pharyngectomy, reconstruction is required. In the rare case of a small defect and no prior neck radiation, a primary closure with a local muscle flap (strap muscle or sternocleidomastoid muscle) can be used. More likely a cutaneous or fascial patch is required. A number of regional flaps can be elevated with a cutaneous skin paddle and rotated to close the pharyngectomy defect. The choices include the pectoralis major (PM) myocutaneous, deltopectoral (DP) fasciocutaneous, island deltopectoral (island-DP) fasciocutaneous, and supraclavicular (SC) flaps. Free tissue transfer is also an option and a thin pliable radial forearm (RFFF) or small anterolateral thigh free flap (ALT) can be used. With a total laryngopharyngectomy, the regional or free flap must be tubed to replace the entire pharynx. There are well-described series of reconstruction of the pharynx using tubed PM or DP flaps. In addition to the RFFF and ALT, the jejunum and gastro-omental free flaps are options. The jejunum is harvested as a tube so that there is one less suture line to leak. With each reconstructive option, there are limitations, and the problem with the jejunum is that it has an inferior voice outcome that sounds “wet” and food may be retained in the conduit, giving the patient significant halitosis. If the cervical esophagus is resected along with the larynx and pharynx, there are fewer options available for reconstruction. The gastric transposition (or “pull-up”) is one way to recreate a pharyngeal conduit and requires collaboration with general surgeons.

For purposes of illustration, reconstruction of a total circumferential laryngopharyngectomy without cervical esophagectomy is described here using an ALT free flap. Other chapters describe the harvest of regional and free tissue transfer that can easily be translated to reconstruction of hypopharyngeal defects.

Operative Period