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

34. The Radial Forearm Flap

Francisco J. Civantos

INTRODUCTION

Cancer of the hypopharynx represents a unique challenge to the surgeon, both oncologically and in terms of reconstruction. These cancers are more aggressive than are lesions that occur nearby in the endolarynx, and there is a lack of anatomic barriers to contain them. While laryngeal cancers are contained by the surrounding cartilage, pharyngeal cancers rapidly invade through the constrictor muscles to involve the parapharyngeal and retropharyngeal spaces, as well as the soft tissues of the neck. There is a propensity to develop lymphatic metastases to the lateral neck and paratracheal regions. Furthermore, cancer of the hypopharynx generally occurs in patients who have a significant history of smoking tobacco and/or drinking alcohol, and because of this, significant cardiac and pulmonary comorbidities need to be managed. The cancers themselves interfere with deglutition, and patients are often in poor nutritional condition at the time of surgery, which can lead to difficulty in healing and other complications.

While early-stage cancers of the hypopharynx may be treated with radiation, chemotherapy combined with radiation, or partial laryngectomy; advanced-stage cancer will require a total laryngectomy, along with partial or total pharyngectomy, even if the larynx is not directly invaded, in order to reconstruct the patient in a manner that protects the airway from aspiration and provides for oral nutrition through successful deglutition. Primary treatment of advanced cancer will also involve postoperative radiation when possible, and in some circumstances, postoperative chemoradiation.

Resection of the cancer must be adequate, with wide margins, and in many cases, this mandates circumferential pharyngectomy. Cancer resection should not be compromised to facilitate reconstruction, and this tends to work best when a separate microvascular reconstructive team is available to enter the procedure fresh at the end of the cancer resection.

Reconstruction of the hypopharynx has passed through several phases. Early techniques involved local flaps of cervical skin, and several stages of surgery, with open fistulas during the intervening periods. These were fraught with complications and poor results in swallowing. The deltopectoral flap represented an important advance, but still usually required at least two stages and a controlled fistula, and hypopharyngeal strictures were common. Single-stage reconstruction became possible with the development of the pectoralis major myocutaneous flap, and this remains an important option in very thin patients or for subtotal pharyngeal reconstruction. It may be a preferred option in the medically infirm.

The type of reconstruction selected should not compromise the resection—for either the primary site or the lymphatic basins—a principle that has limited the use of platysma flaps and other local flaps. The reconstructive procedure should be reliable and should minimize the postoperative deformity, morbidity, and mortality. Failure of the reconstruction in the neck can lead to fistula and even death from vascular rupture. A variety of options now exist for reconstruction of the hypopharynx, including gastric pull-up, enteric microvascular flaps, regional flaps, and cutaneous microvascular flaps. Thinner, more pliable and reliable free flaps have now largely supplanted musculocutaneous pedicle flaps, particularly when a circumferential defect is a realistic possibility.

The gastric pull-up, while avoiding the need for a microvascular anastomosis, has several disadvantages. It has measurable mortality related to pulmonary complications and mediastinitis, neither of which are as significant when reconstructing with cutaneous flaps. Furthermore, primary site complications in the abdomen can occur, which are not an issue with cutaneous flaps. There can be situations where the stomach cannot be mobilized sufficiently to reach the upper portion of a pharyngeal defect or where the distal portion of the flap is lost, leading to a fistula and complications with healing.

Enteric microvascular flaps, such as those obtained from the jejunum or gastro-omental flap, solve some of these problems and have gained some popularity. However, they require not only a laparotomy but also an intestinal anastomosis, which entails additional risks. While laparoscopic techniques can reduce some of these risks, these remain a relatively invasive way to obtain donor tissue. Enteric flaps in general are less well suited for tracheoesophageal prosthetic speech rehabilitation due to the tendency toward excess secretions and a “wet” sounding voice. For all of these reasons, the majority of centers have returned to cutaneous flaps as a means of reconstructing the hypopharynx. The gastro-omental flap has been supported by some in the revision setting, for patients who can tolerate laparotomy because the omentum coats the pharyngeal repair and cervical blood vessels and may be protective in terms of fistula and vascular rupture.

For very thin patients with significant comorbidities, regional flaps, especially the pectoralis major flap, sometimes are the best option because of their relative simplicity. However, for most patients, the pectoralis major flap is very thick, and the lumen of the neopharynx can be obliterated in an attempt to tube thicker skin. It can also be difficult to close the cervical skin over the bulk of the pectoral muscle pedicle. Formation of an adequate stoma, contour of the neck, and ability to close the wound can all be compromised by this bulky muscular pedicle. The most anatomically favorable flaps for reconstruction of the hypopharynx are cutaneous free flaps, including anterolateral thigh, lateral arm, and radial forearm. While the anterolateral thigh flap has been gaining popularity, the reliable radial forearm flap currently continues to serve as the most popular flap for hypopharyngeal reconstruction at many centers.

The radial forearm free flap was originally described in cadaveric studies in 1978 and in a large clinical series in 1981, in the Chinese literature, as a free tissue transfer, by Yang Guofan et al. Its first use for reconstruction of the hypopharynx was described in 1987 by Takato et al. Since then, several large series have reported on the use of this flap for hypopharyngeal reconstruction, and it has become a popular mode of hypopharyngeal reconstruction and is favored over enteric flaps in most centers.

The radial forearm flap provides a sufficiently wide expanse of thin skin (Fig. 34.1) that can be easily tubed while maintaining both an inner lumen and minimizing bulk in order to allow closure of overlying skin and creation of a patent tracheostoma.

FIGURE 34.1 A. Diagram of forearm flap tubed to recreate the hypopharynx. The pharyngeal closure and microvascular anastomosis can be seen on the right. B. Surgical photograph similar to the diagram on the right side of (A). Two venous and one arterial anastomoses are seen. SCM indicates sternocleidomastoid muscle. Other anatomic landmarks are as designated. The pliable forearm flap is being held up to demonstrate the initial suture line on the right pharyngeal wall. In the photograph, there is a strip of mucosa posteriorly, while the prior diagram shows a circumferential reconstruction.

This chapter focuses on the technical details of reconstruction of the hypopharynx with a radial forearm free flap.

Unfortunately, the early symptoms of cancer of the hypopharynx are often nonspecific and include a foreign body sensation in the throat, mild discomfort with swallowing, or mild otalgia. These are generally persistent and continuous, rather than intermittent, and gradually become worse over time. It is common for patients to be misdiagnosed by primary physicians as suffering from pharyngitis or reflux and to be treated with multiple courses of antibiotics and antireflux therapies, prior to making the correct diagnosis, particularly since the presence of superinfection, combined with a placebo effect may lead patients to report improvement after initial antibiotic therapy.

Patients are usually diagnosed with advanced stages of cancer, by which time the patient has developed severe odynophagia, dysphagia, and/or otalgia, which can be unilateral or bilateral depending on the location of the cancer. Some patients will present with cervical adenopathy as the primary complaint, and 65% to 75% of patients will have clinically obvious metastasis to cervical lymph nodes at the time of presentation. Severe dysphagia and inability to eat solids can be a sign of involvement of the cervical esophagus. Exophytic hypopharyngeal cancer can cause the classic “hot potato” voice due to a change in the hypopharyngeal resonance, and direct invasion of the larynx can lead to fixation of the vocal cords, with hoarseness and breathiness of the voice, as well as chronic aspiration. Halitosis, inability to manage secretions, bloody secretions, hemoptysis, and hematemesis are all hallmarks of advanced cancer of the hypopharynx.

The vast majority of patients with cancer of the hypopharynx will have a significant history of tobacco and alcohol abuse. Unlike the nearby oropharyngeal subsite, cancers in this area are rarely related to HPV exposure. Due in part to delays related to alcohol abuse or poor access to medical care, in combination with dysphagia and anorexia related to the cancer itself, some patients who have hypopharyngeal cancer will suffer severe weight loss and present in a state of marked malnutrition, which can greatly compromise healing and the ability to withstand cytotoxic therapies.

When the patient presents to the otolaryngologist with a history of symptoms referable to the hypopharynx, the first step is a complete examination of the head and neck, including palpation of the neck, mirror examination of the larynx and hypopharynx, and in most cases, an office fiberoptic laryngopharyngoscopy is a part of the physical examination. In many cases, an irregularity in the mucosa will be seen that can be exophytic or infiltrative. Raised areas, with a combination of erythroplasia and blanched necrotic tissue, may be identified. More infiltrative cancers can be more difficult to detect visually but can be characterized by ulceration and edema of the overlying mucosa. Lesions may be present on the posterior wall of the hypopharynx above the level of the arytenoids or on the medial, anterior, or lateral walls of the piriform sinuses. Cancers of the postcricoid area or the apex of the piriform sinus cannot be seen directly on routine fiberoptic nasopharyngoscopy and laryngoscopy, but edema and pooling of secretions are usually present. A Valsalva maneuver may open the piriform sinus and assist in the visualization of a tumor. The diffusion of office transnasal esophagoscopes, with the ability to insufflate and suction without requiring specific scheduling and sedation, allows the surgeon to better visualize the more distal lesions at the time of the initial office evaluation. Fiberoptic esophagoscopy, however, can miss a lesion in the piriform sinus or postcricoid area due to loss of visualization at the constricted area of the cricopharyngeus muscle.

Cancer of the medial wall of the piriform sinus commonly extends submucosally at the deep margin into the paraglottic space, and fiberoptic laryngoscopy may reveal thickening or edema of the aryepiglottic folds and vocal fold paralysis. Cancers of the postcricoid area will typically produce edema of the arytenoids and may also lead to fixation of the vocal folds.

Palpation of the neck will allow the surgeon to assess the number of pathologic lymph nodes present, their size, unilaterality versus bilaterality, and whether there is reduced mobility or fixation that portends involvement of vascular structures, cranial and spinal nerves, and deep cervical muscles. The retropharyngeal lymph nodes may also be involved.

Laryngopharyngectomy, with cervical lymphadenectomy and reconstruction of the pharynx with a radial forearm flap, is indicated for advanced cancer of the hypopharynx. For early stage I and II cancer, partial laryngectomy, radiation, or combined chemoradiation are often excellent options. For stage III cancer, combined chemoradiation is commonly considered, and for certain tumor anatomies, stage III (T3N0) lesions might be considered for extended partial laryngectomy. However, for advanced T4 cancer of the hypopharynx, and for recurrent cancer after previous treatment, laryngopharyngectomy is usually indicated.

Radial forearm flaps are contraindicated in patients with inadequate circulation to the hand, as sacrifice of the radial artery in such a case would lead to vascular insufficiency and even gangrene of the hand. The Allen test is used to assess this on physical examination, with concurrent compression of the radial and ulnar arteries, followed by release of the ulnar artery and evaluation of revascularization of the hand by assessing color. When the Allen test is equivocal, the test can be repeated with the assistance of the Doppler ultrasound to assess blood flow and pressure in the fingers (digital Doppler-assisted Allen test). If a patient fails his or her Allen test, other reconstructive options must be considered. Generally, the pectoralis major flap, anterolateral thigh flap, or lateral arm flap provide reasonable alternatives.

This procedure represents a major intervention and can take 10 or more hours to accomplish. Patients with severe comorbidities, such as severe cardiovascular disease, marked malnutrition and debilitation, end-stage renal or pulmonary disease, or dementia, may not tolerate such prolonged surgery.

Fine Needle Aspiration

When patients present with palpable cervical lymph adenopathy and the primary cancer is not well visualized, fine needle aspiration and cytologic analysis can be used to establish the diagnosis of cancer and justify imaging and endoscopy. It is not mandatory if biopsy of the primary cancer is planned.

Endoscopy

The way to most accurately diagnose cancer of the hypopharynx is direct laryngoscopy with biopsy under general anesthesia. Failure to visualize a lesion on office examination should not dissuade the surgeon from proceeding with direct laryngoscopy in the presence of unexplained, persistent foreign body sensation in the throat, discomfort with swallowing, or otalgia. Typically rigid or flexible esophagoscopy is also performed to rule out direct extension or second primary cancers involving the esophagus. Screening bronchoscopy may also be performed. The risk of second primary cancers of the upper aerodigestive tract, esophagus, or lungs is estimated at 10% to 20% and is a particularly significant issue for hypopharyngeal cancers relative to other anatomic subsites in the head and neck. Early second primary cancers are not always seen on imaging and may occasionally be detected on careful endoscopy.

A biopsy is mandatory in order to establish a diagnosis and potentially recommend treatments that are radical or toxic. The biopsy is usually obtained with a cup forceps, and infrequently, other microsurgical instruments, such as sickle blades, microscissors, or lasers, are needed to perform incisions and obtain biopsies of submucosal or cartilaginous tumors, or indurated cancers that are difficult to enter with a cup forceps. Generous biopsies, including some performed at the interface between the cancer and normal adjacent tissue, should be performed, in order to ensure that sufficient viable tissue is obtained to make an appropriate pathologic diagnosis.

Head and neck oncologic surgeons will commonly receive patients who have already undergone direct laryngoscopy and carry a biopsy-proven diagnosis of cancer, most commonly squamous cell carcinoma. In this situation, the surgeon may develop a relatively complete understanding of the anatomy of the lesion, based on office nasopharyngoscopy or transnasal esophagoscopy, and imaging studies, and may elect to repeat the direct laryngoscopy immediately prior to ablative surgery, during the same intervention. In other cases, a repeat direct laryngoscopy and esophagoscopy at an earlier date may be indicated in order to ascertain whether circumferential involvement or esophageal involvement is present, and better plan the reconstruction, as well as to ensure adequate staging and make proper decisions regarding the use of chemotherapy and radiation as alternative approaches in the management of these cancers.

Imaging Studies

A barium swallow may be useful in a patient with symptoms of dysphagia in whom a visible lesion is not present, although in a setting of high suspicion, the surgeon will often elect to bypass this study and proceed to direct laryngoscopy and esophagoscopy. A negative barium swallow does not exclude cancer in the hypopharynx, and results of such a contrast study should be interpreted with caution.

When the diagnosis of cancer of the hypopharynx is strongly suspected or confirmed, an anatomic imaging study, most commonly a contrasted computerized tomography (CT) of the neck, is indicated in order to delineate the anatomy of the cancer, including its superficial and deep extension. The presence of cartilage destruction in the larynx is best identified on CT. The extent of invasion of larger metastatic nodes and the number of suspicious nodes can also be determined. Magnetic resonance imaging with or without gadolinium contrast can be used when the patient is allergic to iodine, or as a complementary study to assist in answering specific questions, such as the presence of invasion of the retropharyngeal fascia or vascular structures and the presence of gross perineural invasion, findings that may predict an inability to completely clear the resection margins of cancer.

Positron emission tomography–computerized tomography (PET–CT) can be useful in determining whether equivocal lymph nodes palpated or seen on imaging actually harbor malignancy. It can also identify mediastinal lymph node metastases, pulmonary nodules, and other distant metastases. However, false positives related to inflammatory processes are common, and the surgeon must be skeptical in the interpretation of PET and utilize anatomic imaging and clinical knowledge to make appropriate decisions regarding treatment. Alternatively, a CT of the thorax with contrast will image the highest risk sites, the mediastinum and lungs, for the presence of distant metastases.

Histopathology

More than 95% of malignant hypopharyngeal tumors are squamous cell carcinomas. In addition to the classic variant, subtypes of squamous cell carcinoma occasionally are described, such as adenosquamous, acantholytic, basaloid, spindle cell, papillary, and nasopharyngeal type (lymphoepithelial). Most of these behave similarly to classic squamous cell carcinoma. Verrucous carcinoma is well differentiated and indolent and most commonly is treated surgically in order to avoid purported risk of transformation to more aggressive histologies when treated with radiation therapy. It grows with pushing borders and rarely metastasizes. Verrucous carcinoma is infrequent in the hypopharynx and occurs most commonly in the oral cavity and occasionally in the larynx. Acantholytic and papillary squamous cell carcinomas can be less infiltrative than the classic variant. Nasopharyngeal-type carcinoma occurs rarely in the hypopharynx, and while high in grade, these cancers are characterized by exquisite sensitivity to chemotherapy and radiation.

Nonsquamous carcinomas, such as mucoepidermoid carcinoma and neuroendocrine carcinomas, can occur. Their behavior is often predicated by their grade, which can be high, intermediate, or low. Low-grade neuroendocrine carcinomas are referred to as carcinoid tumors and are much more common in the lower gastrointestinal tract. Sarcomas and lymphomas can also occur in the hypopharynx but are exceedingly rare.

The patient is brought to the operating room and placed under general endotracheal anesthesia. If the presence of exophytic cancer makes standard intubation difficult, awake fiberoptic intubation is an option, but more commonly awake tracheostomy is performed to allow for induction of anesthesia, since a tracheostomy is planned as part of the procedure. After induction of anesthesia, the eyes are protected with tape and hard goggles, pressure points are padded, and the head of the bed is rotated 180 degrees away from the anesthesia station. Dynamic compression stockings are placed for the prevention of pulmonary embolus. Direct laryngoscopy is then performed to confirm the anatomy of the cancer. Rigid esophagoscopy and bronchoscopy are also performed. The presence of esophageal involvement below the cervical inlet, or involvement of the inferior aspect of the trachea, may make the planned procedure impossible; alternatives, including gastric pull-up, sternectomy, mediastinal tracheostomy, or nonsurgical options, may need to be considered. Appropriate preparation is performed with antiseptic solution and draping of the head and neck, forearm, and pectoral area (for a possible backup flap). I begin the open procedure by prepping and draping the patient to the neck as well as to the forearm.

The resection, tracheostomy, and neck dissections are open surgical procedures, and there are a wide variety of styles that surgeons have in accomplishing these procedures. I favor a meticulous dissection with the use of scalpel, bipolar cautery, DeBakey forceps, Gerald forceps with teeth, and fine Jamison scissors. I use electrocautery for the less delicate portions of the dissection, and ties or clips for control of vessels.

Elevation of the flap involves clipping multiple vascular branches that come off of the pedicle, and automatically reloading clips will expedite this procedure. A tourniquet is usually used during flap elevation to temporarily maintain hemostasis at the donor site. For the microvascular anastomosis, I have a tray of shorter microvascular instruments and a tray of longer microvascular instruments, including jeweler’s forceps, microvascular needle holders, single and frame sizes 3 and 4 arterial and venous clamps, larger vascular bulldog clamps, and 9-0 nylon on a V100-3 needle. The Synovis GEM microvascular anastomosis coupler can be used for the venous anastomosis if adequate-sized matching vessels are found, and this can reduce operative time significantly.

The pectoralis major donor site is also prepared as a backup flap. It is preferable to use two teams, and one begins working on the forearm, while another works on the neck. Apron style incisions or horizontal incisions can be used, and subplatysmal flaps are raised up from the sternal notch to the submental area. Laterally, the flaps expose the sternocleidomastoid muscles and angle of the mandible. Neck dissections are performed that are most commonly bilateral. If palpable adenopathy is present, the surgeon may elect to dissect level 5 (posterior triangle), but most commonly, levels 2 through 4, the jugular chain, are dissected. If there are clearly indications for postoperative radiation, level 5 can be left undissected even in the presence of palpable jugular adenopathy, as level 5 will be included in the radiation field.

The neck dissections are performed in the following manner: The sternocleidomastoid muscle is sharply delineated with a no. 15 blade. Hemostasis is obtained with bipolar cautery. The spinal accessory nerve is identified as it exits the superior portion of the muscle and preserved. I follow the nerve with a McCabe nerve dissector and divides overlying tissue with a harmonic scalpel or bipolar cautery. I take the IIB nodes above the nerve either in continuity or as a separate specimen. The lymphatics are then reflected off of the deep cervical fascia, cervical plexus, and the sheath of the jugular and carotid artery using a no. 15 blade and bipolar cautery. If bulky adenopathy is present unilaterally, the jugular vein should be taken, but at least one jugular vein should be preserved to avoid complications, including cerebral edema. I elevate the tissues in a plane just above the superior thyroid vessels and come off the strap muscles. Anterosuperiorly the digastric muscle serves as the limit of dissection, and removal of level 1 is rarely indicated for hypopharyngeal lesions. An identical procedure is performed on the contralateral side. At this point, removal of levels 2 through 4 has been completed. Paratracheal and upper mediastinal lymph nodes will commonly also be resected in the context of the laryngectomy, particularly for hypopharyngeal lesions extending into the apex of the piriform sinus or esophagus.

During the neck dissections, specific care must be taken to dissect out arteries and veins that may serve as potential donor vessels, with sufficient length to provide for flexibility in designing blood vessel geometry at the time of the microvascular anastomosis. The facial artery is preserved, taking it at the angle of the mandible and clipping it distally, as well as the facial vein, and external jugular vein, again taken distally and clipped. Other potential donor blood vessels, such as the external carotid artery, internal jugular vein, superior thyroid veins, and transverse cervical veins, are often left intact during the neck dissection as their ligation is not necessary to facilitate the lymphadenectomy. These can be divided later if necessary for microvascular anastomosis. Microvascular clamps should not be placed on the vessels during the neck dissection, in advance of the microvascular anastomosis, as prolonged vascular compression can lead to ischemia of the endothelium at the clamp site and create a sluffed area that will lead to thrombosis. Instead, ligaclips are used, and the vascular clamps are placed when vessels are trimmed immediately before beginning the microvascular anastomosis.

Laterally, the retropharyngeal space is dissected, separating the carotid and jugular sheaths from the hypopharynx. If a circumferential pharyngectomy is planned, I do not divide the inferior pharyngeal constrictor muscle, but for partial pharyngectomy, the constrictor is divided at its attachment to the thyroid cartilage on the less involved side. The superior laryngeal vascular pedicle is ligated on the side where the thyroid is preserved, and the superior thyroid vessels are ligated on the side where the thyroid is resected. The suprahyoid muscles are then released from the hyoid bone, cutting directly onto the hyoid bone. A sensation of release is noted, and greater laryngeal mobility is achieved, when the suprahyoid muscles are completely transected and the submucosal space is entered.

If there is involvement of superior portions of the hypopharynx, adjacent or superior to the hyoid bone, the surgeon must dissect out the branches of the external carotid artery and the hypoglossal nerves and elevate these off of the pharynx and the base of the tongue prior to making an incision into the pharynx. Some branches of the external carotid artery and even the hypoglossal nerve may need to be sacrificed due to deep extension of the cancer. At least one lingual artery and one hypoglossal nerve must be preserved in order to maintain viability and function of the oral tongue.

Once the hypopharynx has been skeletonized and the mentioned blood vessels and nerves protected, incisions are made into the mucosa, either saving a strip of hypopharynx posteriorly or circumferentially resecting the hypopharynx (Figs. 34.2 to 34.4).

FIGURE 34.2 Pharyngolaryngectomy defect with posterior pharyngeal wall preserved. v, veins; a, artery; ph, pharyngeal remnant; t, base of the tongue; h, hypoglossal nerve. The endotracheal tube can be seen at the inferior aspect of the field.

FIGURE 34.3 Total laryngopharyngectomy specimen. e, laryngeal surface of epiglottis; a, left arytenoid; c, cancer involving apex of piriform sinus, posterior wall of the hypopharynx, and cervical esophagus.

FIGURE 34.4 A,B. Circumferential pharyngectomy in (A) diagrammatic and (B) photographic image. The black arrow on the right designates the retropharyngeal fascia. SCM, sternocleidomastoid muscle. The sternocleidomastoid muscle is absent from the diagram on the left.

The paratracheal nodes are dissected while awaiting the results of the frozen sections. The tissues from the medial aspect of the inferior portion of the common carotid artery and jugular vein, across the retroesophageal fascia, and off of the esophagus and trachea, including midline pretracheal tissue, are included in this dissection. When justifiable, a unilateral midline compartment dissection is performed in order to leave the parathyroids on the contralateral side undissected. The parathyroids are identified and preserved on the dissected side. The superior parathyroid can generally be left undisturbed superior to the dissection. Whenever possible, the inferior parathyroid is visualized and reflected laterally on its vascular pedicle. Compromised parathyroids are minced and reimplanted in the sternocleidomastoid muscle.

While the tumor resection is proceeding in the neck, a second surgeon will begin elevating the forearm flap. The anatomy of the forearm is shown in Figure 34.5. Approximately a 13- by 10-cm flap will be sufficient for a complete circumferential pharyngeal reconstruction from the postcricoid area to the superior oropharynx. Generally, the nondominant arm is preferred. The Allen test is repeated in the holding area in order to confirm adequate circulation to the hand with sacrifice of the radial artery.

FIGURE 34.5 Anatomy of the forearm. Fullthickness flap of subcutaneous tissue is elevated off of the brachioradialis and the extensor carpi radialis medial to the radial artery pedicle (which runs with venae comitantes, not shown). The flap is also elevated from the flexor carpi radialis, palmaris longus, flexor digitorum superficialis, and flexor carpi ulnaris. Care is taken to leave the ulnar vessels, shown, under deep fascia. The paratenon is left on all tendons in order to facilitate take of the skin graft. The typical location of the skin flap is indicated by the blue rectangle.

Once the primary site resection and lymphadenectomies are completed, the surgeon who will perform the reconstruction will begin preparing the blood vessels in the neck, using standard microvascular technique, including placement of arterial and venous bulldog microvascular clamps and recutting the blood vessels with a pair of sharp scissors or blade in order to achieve a straight, clean cut, and trimming excess adventitia from the ends of the vessels. The site of the vessel cut and position of the donor vessels are planned based on the anatomy of the already elevated flap pedicle. The vessels, and particularly the artery, are bled, in order to assess for adequate blood flow. In general, the forearm flap is not harvested until frozen sections are known to be clear, as additional ablative work could prove necessary, and it is preferable that this not be performed while the flap is ischemic.

The skin paddle is marked, and a proximal incision with a radial curve going all the way up to the antecubital fossa is drawn. The patient is prepped and draped to the arm up to the axilla with a tourniquet on the upper arm. The visible superficial forearm veins are marked. The upper extremity is then partially exsanguinated with an Esmarch elastic bandage wrapped around the arm in a raised position, in order to push the intravascular fluid back into the rest of the body, and the tourniquet is inflated to 300 mm Hg in order to minimize blood loss during flap elevation. The anatomy of the forearm is shown in Figure 34.5.

The order of steps in flap elevation can be flexible and varies between surgeons. I make a curvilinear incision above the flap first and elevate skin flaps in a subdermal plane over the proximal forearm and then dissect out the superficial forearm venous system, leaving a variable pannus of adipose tissue around the vessels depending on the reconstructive needs. The incision is then continued around the superior and medial aspects of the flap skin paddle. The skin is divided and subcutaneous adipose tissue transected with a 15-blade. Bipolar electrocoagulation is used for hemostasis, and small subcutaneous veins are clipped and transected as needed. The flap is commonly elevated from the ulnar side laterally going in a suprafascial plane until the tendon of the flexor carpi radialis muscle is reached. Care is taken to leave sufficient paratenon on the tendons, and the plane just deep to the subcutaneous adipose tissue can be followed in order to leave a thicker covering. All proximal and distal subcutaneous veins are elevated, clipped or ligated, and transected. Next, the radial aspect of the dissection is performed in a similar manner. The skin and subcutaneous adipose tissue are divided. Dorsal branches of the cephalic vein to the forearm are elevated and transected between clamps and tied using 3-0 Vicryl ties. The flap is elevated again in a suprafascial layer preserving the sensory branch of the radial nerve to the anatomic snuffbox with all its small ramifications. Dissection is continued until the medial aspect of the tendon of the brachioradialis muscle is reached. Next, the proximal incision is divided all the way up to the antecubital fossa. Fascial incisions are made on the bellies of the flexor carpi radialis muscle and brachioradialis muscle, and the muscles are rolled away from the septum. The radial vascular pedicle is identified, and numerous perforating vascular branches to the surrounding muscles were elevated, clipped, and transected. Dissection can be performed from distal to proximal or from proximal to distal, separating the tendons, and protecting the septum between the pedicle and the skin paddle. The deep aspect of the pedicle is freed, and perforating vessels to the surrounding muscles are clipped and transected. The distal aspect of the pedicle is identified as it exits the skin island distally. Multiple venae comitantes are clipped and transected, while the distal aspect of the radial artery is elevated and transected between clamps and ligated using 2-0 silk suture ligatures. The upper portion of the flap pedicle is completely freed distal to proximal and dissected until the recurrent radial artery is identified. At this level, numerous venous branches to the brachial comitantes system and the ulnar comitantes system, as well as proximal perforators to the surrounding muscles, are identified, clipped, and transected. A large connecting branch between the venae comitantes and the cephalic vein can commonly be found and protected and incorporated with the flap, and the cephalic vein dissected proximally until it is found to divide into significant branches, both of which were used for microvascular anastomosis. If a communicating branch between the venae comitantes and the superficial venous system is not present, the flap will survive quite well with venous anastomoses from either the superficial or deep systems. The superficial veins are much larger, and when available, incorporation of the superficial venous plexus is preferred. Occasionally in a patient who has had many intravenous lines, perhaps because of prior chemotherapy, only the venae comitantes are available. Once raised, the flap is set to rest in situ, placing tacking sutures in a favorable position in order to avoid kinking of the pedicle, while the resection is being completed. The tourniquet is deflated and completely removed in order to ensure that no arm compression persists.

Flap monitoring for a hypopharyngeal reconstruction can be challenging, as the flap is buried and cannot be visualized directly at the bedside during the postoperative period. For this reason, it can be beneficial when possible to exteriorize a marker skin paddle into one of the skin incisions in order to monitor the flap. This can be performed if a separate proximal perforator can be identified, in order to design a small additional skin paddle around it. De-epithelialization of a portion of the flap in order to exteriorize an area is not advisable, as the de-epithelialized dermis can compromise the pharyngeal repair and serve as a conduit for fistulization. If a separate skin paddle can be designed on a perforator, it can be brought out to the skin incision for monitoring. This may not be possible if all of the skin of the forearm is needed for a large pharyngeal reconstruction.

Once the cancer resection is completed, the reconstructive surgeon must turn his attention to the anatomy of the defect and the donor vessels in the neck. Limited areas may benefit from initial primary approximation of mucosa. This is common at the glossopharyngeal folds, and these sutures can be placed prior to inducing flap ischemia. The dimensions of the flap relative to the defect are assessed, and the geometry of the vascular pedicle is planned. Donor vessels are selected, vascular clamps are placed, and vessels are cut cleanly, dilated when necessary, and trimmed of excess adventitia. Aggressive excessive trimming of adventitia should be avoided as it can weaken and thin the walls of donor arteries and veins. Clamps are released to assess arterial flow. As clamps are placed and microvascular work is initiated, the surgeon should be careful to identify important neurovascular structures, such as the hypoglossal nerve, preserved lingual nerve, carotid artery, and vagus nerve, and ensure that the clamps and instruments are not placing pressure on these structures.

Once the frozen section results are returned as negative the flap can be harvested. The vessels are clamped proximally and transected. The radial artery is ligated using 2-0 silk suture ligatures, while the branches of the cephalic vein are ligated using 3-0 Vicryl suture ligatures. The sensory nerve is transected under the cephalic vein. In the setting of a hypopharyngeal reconstruction, there is no need to anastomose the sensory nerve. The flap is passed up into the neck, and the artery is irrigated with heparinized saline until clear fluid can be seen exiting the veins. Each vein is also irrigated with heparinized saline. In the meantime, a 0.018-inch split-thickness skin graft is harvested from the left thigh. It is trimmed to match the size of the defect in the forearm. The forearm is irrigated and checked for hemostasis. While the anastomosis proceeds in the neck, another team can begin closing the forearm donor site. The proximal aspect is closed in two layers using interrupted 3-0 Vicryl sutures, and skin staples over a 19-French suction drain. The distal aspect of the defect is covered with a skin graft, and 4-0 chromic sutures are circumferentially used. The skin graft is pie-crusted and tacked down to the muscles. It is secured with a Xeroform bolster tied to the distal forearm with 2-0 silk sutures. The wound is dressed, and the forearm is wrapped with Kerlix bandage. At the end of the procedure, a splint is used to stabilize the upper extremity with the wrist slightly extended and the fingers in neutral position.

In the meantime, the cut edges of the recipient vessels of the flap are freshened and cleaned. The vessels are dilated as needed to create a favorable size match with the donor vessels. The flap is partially inset in order to plan vessel geometry. However, the flap itself can overhang the vascular anastomosis, and once the geometry has been planned, the surgeon may elect to release tacking sutures and reposition the bulk of the flap farther away from the blood vessels in order to temporarily facilitate microvascular anastomosis.

Although some surgeons prefer to close the pharynx prior to microvascular anastomosis, I feel that this increases ischemia time excessively and I prefer to place a small number of sutures in order to plan vessel geometry and then proceed with microvascular anastomosis. Sufficient distance from the donor vessels to the flap is needed in order to allow for looping of the vascular pedicle without kinking. End-to-end arterial anastomosis is generally performed using interrupted 9-0 nylon sutures.

End-to-end venous anastomosis can be done either with sutures or using a coupling device. Some surgeons prefer to have at least one end-to-side venous anastomosis directly to the jugular vein. Plain 2% lidocaine or papaverine is used to irrigate the anastomosis and vascular pedicle in order to prevent vascular spasm. Clamps are removed, and the flap should revascularize. It is important to delay detailed assessment of color, warmth, and turgor of the skin paddle for at least 10 minutes in order to ensure adequate time to recover from the period of ischemia. Blood flow through the flap pedicle is assessed using the Doppler probe.

The pharyngoesophageal repair begins with cricopharyngeal myotomy to prevent stenosis and facilitate tracheoesophageal speech (see Fig. 34.1B). Extramucosal myotomy is done with a no. 15 blade or scissors, with a finger inside the digestive tract lumen protecting the mucosa. The circumferential muscular fibers are transected until the circular muscle band was completely released. The mucosa is completely preserved. A beveled cut at the level of the esophagus, if possible at the time of the resection, will serve to reduce the risk of stenosis. If this is not possible, a “fish-mouth” cut can be made in the esophagus, and the tip of the flap can be inset into it, in order to reduce the chances of stricture at a narrow, circumferential esophageal anastomosis. While suturing, I am careful to maintain the esophagus stretched to its maximal dimension during closure. A tracheal dilator placed into the esophagus can be helpful to determine the stretched diameter of the esophagus and not constrict it as the flap is sutured to it.

For the pharyngoesophageal repair, the flap can be positioned with the vascular pedicle oriented horizontally or vertically. The vessels are positioned with the pedicle resting on the prevertebral planes wherever possible, and the pedicle can exit the flap more superiorly or more inferiorly, based on the planned vascular geometry, and looped gently toward the donor vessels in a manner that will minimize the risk of kinking when the head is flexed or turned. Inverted vertical mattress (interrupted Connell) sutures with 3-0 Vicryl are used circumferentially to suture the skin of the flap to the mucosa of the esophagus and pharynx. In the early stages of the closure, when the lumen is open, standard vertical mattress sutures can also be used, as one might use on skin. The flap is anastomosed to the pharyngoesophageal stump inferiorly, and the upper corners are attached to the superior pharyngeal mucosal remnants. Superior circumferential closure is performed marching along the posterior pharyngeal wall, to the level of the contralateral superior pharynx or tonsillar fossa, and back to the base of the tongue. The flap is turned on itself and finally anastomosed to itself in a vertical plane (see Fig. 34.1A). A feeding tube is passed transnasally through the flap-lined lumen and esophagus, to the stomach, and sutured to the columella. The last sutures on the flap are placed while leaving several untied, to facilitate visualization, and then all are tied at the end of the closure.

Once the pharyngeal repair is complete, vessel geometry is checked. Occasionally, tacking sutures are used to maintain favorable pedicle anatomy. Wounds are irrigated and checked for hemostasis. A tracheostoma is fashioned after resecting skin from either the inferior or superior skin flaps as needed to ensure that the stoma does not collapse and maintains adequate dimensions. The tracheostoma is sutured using interrupted extramucosal Prolene or 3-0 Vicryl sutures, and ultimately running 4-0 chromic sutures between the mucosa and the skin. This can be facilitated by brief apneic episodes where the tube is briefly removed from the trachea to place a suture, and then replaced, resuming ventilation. Care should be taken during this maneuver to not allow the patients’ oxygen saturation to drop below 90% and to ventilate sufficiently to maintain low CO₂ levels. Suction drains are placed in the neck. Wounds were closed in two layers using interrupted 3-0 Vicryl sutures and skin staples. If a marker skin paddle has been designed, it is incorporated into the skin closure, often just above the stoma. Prolene sutures are placed at various points on the neck to mark sites for postoperative Doppler checks. The procedure is completed at this point, and the patient is turned over to the care of the anesthesiology team to reverse general anesthesia.

The patient is initially placed in an intensive care setting. Many surgeons use either aspirin, dextran, or other medications designed to prevent thrombus formation during the postoperative period. My own preference is to use aspirin only, administered rectally, immediately postoperatively, and to give a single dose of intravenous heparin, 5,000 units, in cases that have become problematic, either due to poor condition of the blood vessels or witnessed episodes of thrombosis.

Continuous cardiac monitoring and monitoring of oxygen saturation are performed. Dynamic compression stockings and subcutaneous heparin or fragmin are used to prevent deep venous thrombosis. Nursing care is focused on care of the tracheal stoma, with removal of crusts, and saline irrigation and suctioning of the trachea. Suction drains must also be cleansed, monitored, and emptied. Patients are weaned from mechanical ventilation rapidly when possible and required to get into a chair on the first day postoperatively and on subsequent days are ambulated as much as possible. Flap monitoring is important as flaps can be salvaged by revision of the vascular anastomosis if thrombosis is detected early. Flaps are monitored by Dopplers placed by the nurses and physicians at 1-hour intervals for the first 2 days and 2-hour intervals for another 2 days. Specifically for hypopharyngeal flaps, implantable Dopplers placed directly on the vein can be very useful and give a continuous confirmation of vascular integrity. However, these also have their limitations, as they can become dislodged and fail to read, despite a healthy flap. If a skin island has been exteriorized, it is monitored for color, capillary refill, and bleeding after a needle prick or scratch. It must be kept in mind that the monitor island can be compromised due to issues with specific perforators, and the main flap may still be intact. In rare circumstances, direct laryngoscopy must be performed to assess the flap. More commonly, bedside ultrasound can be used if the Doppler studies are in doubt. Wounds are monitored for fistula development while in the hospital. If a patient develops signs of fluctuance and inflammation, drainage of an abscess early can prevent larger abscess formation and secondary tissue injury. Flap monitoring generally is reduced to twice daily after the 5th postoperative day, and patients can be ready for discharge by the 6th or 7th postoperative day.

It is important to ensure that patients and families are adequately instructed in care of the tracheostoma, and in some situations, placement in an extended care facility is necessary to ensure adequate care occurs. Failure to adequately care for the stoma can lead to airway obstruction and even death.

The majority of patients will develop at least a minor complication after hypopharyngeal reconstruction. The rate of pharyngocutaneous fistulization has been reported at approximately 31%. A pharyngocutaneous fistula can drain over major blood vessels and lead to vascular rupture, followed by flap necrosis, stroke, or death. Breakdown around the tracheostoma can also lead to vascular exposure, desiccation, and vascular rupture. Mortality after pharyngoesophageal repair has been reported as high as 10% but should be lower than this with proper patient selection, careful attention to detail, and the use of a cutaneous free flap rather than an enteric reconstruction.

Partial or complete necrosis of the flap can occur that will lead to massive pharyngocutaneous leakage if a secondary reconstruction is not rapidly performed. While rates of complete free flap failure are less than 5% in experienced hands, the group of patients undergoing hypopharyngeal reconstruction are typically compromised by malnutrition, prior radiation, poor peripheral circulation, and other issues, and the rate of vascular thrombosis may be higher in this group.

Other surgical risks include intraoperative injury of lower cranial nerves or carotid artery, chyle leak related to uncontrolled injury of the thoracic duct, stricture, dysphagia requiring a feeding tube, and intractable hypocalcemia. As in any major operation, general medical complications not directly connected to the surgical maneuvers can also occur, including deep venous thrombosis, pulmonary embolism, myocardial infarction, pneumonia, and renal failure.

Five-year survival for stage IV cancer of the hypopharynx treated with surgery followed by external beam radiation therapy has been reported to range between 30% and 50%. Palliation and local control are achieved in a larger percentage of patients. Functionally, patients are similar to other laryngectomies with regards to issues of speech rehabilitation, with the caveat that in some cases, pooled secretions in the reconstructed hypopharynx can make tracheoesophageal speech sound “wet” and difficult to understand. Many patients acquire quite good tracheoesophageal speech, and the “wet” voice is a greater problem after reconstruction with jejunum. Results with regard to deglutition are variable. Strictures can occur requiring dilation in up to 15% of patients. Furthermore, even if stricture is successfully avoided through superior surgical technique, lubrication and peristaltic function of the hypopharynx are lost after circumferential hypopharyngeal reconstruction with a forearm flap. Ingested nutrition moves through the repaired pharyngeal segment by gravity alone. Typically, patients wash meals down with fluids, using the tongue base to push food through the tubular reconstruction. While some patients can eat almost anything, some must restrict themselves to a full liquid or pureed diet.

• Unexplained continuous odynophagia, dysphagia, or otalgia for more than a month mandates direct laryngoscopy under general anesthesia.

• Initial endoscopy should focus on ruling out esophageal involvement beyond the esophageal inlet, fixation of cancer to the prevertebral fascia/muscle, and tracheal involvement, all of which could compromise subsequent resection and reconstruction.

• Careful informed consent should be obtained, and particularly in the less educated patient, repeated on multiple occasions, regarding the presence of a permanent tracheostoma, speech and swallowing difficulties after surgery, and the risk of healing problems, infection, vascular rupture, and tumor recurrence among other complications.

• During the scheduling period, attempts should be made to improve the patient’s nutritional status, using liquid supplements and feeding tubes if indicated.

• For emaciated, malnourished patients and those with significant comorbidities, the pectoralis major flap may be a preferred alternative, particularly if the subcutaneous tissue of the chest is thin and the patient is not extremely muscular.

• Patients who have failed their Allen test, who must have a different flap, are likely to prove to be vasculopathic in other parts of the body, and the surgeon should plan accordingly. Poor distal circulation can be anticipated in pedicled flaps, and atherosclerotic changes can be anticipated in donor vessels.

• If unexpected involvement of the prevertebral fascia is encountered, this fascia can be resected. While this portends a poor prognosis, an attempt can be made to strip the vertebral bodies, taking care to avoid the vertebral arteries inferiorly.

• Intraoperatively the surgeon should plan for a potential fistula and cover blood vessels with vascularized tissue whenever possible.

• Meticulous microvascular technique is necessary to achieve success.

• The surgeon should avoid prolonged use of vascular clamps. Precise suture placement under high magnification should be practiced, with careful observation to detect endothelial flaps, tears, and other subtle factors that could lead to thrombosis. Whenever possible, vessels should be cut back to areas away from atherosclerotic plaque or valves.

• If suturing through plaque, the surgeon should try to pass the needle from the lumen outward in order to avoid creating a separation of the endothelium that could subsequently lead to vascular dissection.

• The most important factor in flap success is vessel geometry.

• Meticulous pharyngeal closure is essential and should not be rushed.

• Exteriorized skin paddles should be separated from the internal flap by complete removal of dermis, as a dermal connection can facilitate fistulization.

• Careful postoperative monitoring for signs of local inflammation, and early drainage of abscess or fistula, reduce the risk of greater tissue injury or vascular thrombosis from fistula.

• Many local wound complications, including fistulas and breakdowns around the tracheal stoma, can be managed conservatively with local wound care. Heavily irradiated patients may benefit from hyperbaric oxygen therapy. The surgeon, however, must have a high index of suspicion regarding possible exposure of major blood vessels.

• If the trachea must be transected low in the mediastinum, significant attention should be paid to the protection of the carotid and innominate arteries and jugular and innominate veins. If necessary, additional flaps should be brought in.

• Issues with healing can occasionally occur late, even 4 to 6 weeks after surgery.

• Head and neck surgical tray

• Sterile tourniquet

• Jeweler’s forceps

• Micro needle holders

• 3 and 4 arterial and venous frame and single clamps

• Vascular bulldog clamps

• 9-0 nylon suture on V100-3 needle

• Synovis GEM microvascular anastomosis coupler

SUGGESTED READING

Varvares MA, Cheney ML, Gliklich RE, et al. Use of the radial forearm fasciocutaneous free flap and montgomery salivary bypass tube for pharyngoesophageal reconstruction. Head Neck 2000;22(5):463–468.

Marin VP, Yu P, Weber RS. Isolated cervical esophageal reconstruction for rare esophageal tumors. Head Neck 2006;28(9):856–860.

Andrades P, Pehler SF, Baranano CF, et al. Fistula analysis after radial forearm free flap reconstruction of hypopharyngeal defects. Laryngoscope 2008;118(7):1157–1163.