65: Mediastinal Tracheostomy

Despite progress in tracheal surgery over the past 60 years, to date, there is no suitable substitute for the trachea to bridge long gaps after resection. The adult trachea is usually approximately 9 to 13 cm long. Currently, approximately half of the adult trachea can be removed surgically and reanastomosed with various tracheal release and mobilization maneuvers. More extensive tracheal resections are limited by the lack of dependable and predictable replacements. This limitation is quite apparent by the occasional necessity of creating an anterior mediastinal tracheostomy (MT) in palliative, curative, or sometimes emergent or “bail out” procedures.

An anterior MT involves the construction of a tracheostomy stoma on the anterior chest wall using the intrathoracic trachea when there is insufficient length to reanastomose the remaining trachea or to bring the trachea out of the superior mediastinum for a standard suprasternal stoma. The procedure involves laryngectomy (if not done previously) and resection of the upper sternum, the medial third of the clavicles, and the first and usually second ribs. This provides access to the intrathoracic trachea with excellent exposure of the superior mediastinum and brings the chest wall down to the remaining shortened trachea to avoid tension on the stoma. The primary indications for this operation are mostly limited to advanced cervicothoracic neoplasms in the superior mediastinum, although it is done occasionally for benign disease. The indications for this procedure have become less common with the refinement of radiation therapy and tracheal surgery and are confined to very selected clinical scenarios. Tumors in this location that are amenable to resection are quite rare.

Few thoracic surgeons or institutions have any extensive experience with this procedure. MT is a complex procedure that is performed in a difficult, unfamiliar anatomic location and is associated with very high morbidity and mortality. However, as described in multiple series in the literature, curative and palliative resections of advanced or recurrent carcinomas in this region can be accomplished with acceptable outcomes. Often the patient will experience a prolonged recovery with a high risk of associated serious complications. MT requires dedicated postoperative care delivered by experienced medical and nursing teams. With a successful outcome, however, the functional result is the equivalent of laryngectomy.¹ When undertaking this radical procedure, one must show good clinical judgment in patient and case selection. Also, it is imperative to determine whether the procedure is being done for cure or palliation because 1 or 2 cm of length can change the complexion of the procedure.

Patient Characteristics

Patients must be selected carefully, and the surgeon's preoperative preparation should be meticulous. The typical patient requiring an anterior MT usually is afflicted with an advanced cervicothoracic malignancy involving either the thyroid, larynx, pharynx, trachea, or esophagus that often invades adjacent structures (Fig. 65-1). It also can be a recurrent tumor at the site where the trachea or larynx was resected previously, such as a recurrence at the site of the tracheal stoma.

An important consideration is whether the patient will need to have restoration of alimentary continuity (Table 65-1) because this adds substantially to the duration, complexity, and stress of the operation. The general condition of the patient should be good enough to tolerate this radical procedure. A thorough history, physical examination, and clinical workup should focus on the following: preoperative nutritional status, weight loss, cardiac and respiratory function, smoking status, and a history of diabetes or steroid dependence. All these conditions should be optimized, and the patient should cease smoking several weeks before surgery. The patient also should undergo preoperative respiratory conditioning, including incentive spirometry and respiratory physical therapy. Other important details include a history of prior abdominal surgery (important to know the esophageal substitution), laryngectomy, tracheal resection, chemotherapy, and radiation therapy. A prior history of radiation therapy will make the neck structures, including the great vessels, more fixed. In addition, tracheal blood supply may be compromised, increasing the risk of ischemic breakdown and delayed healing. Finally, and perhaps most important, it is the surgeon's job to make sure that the patient is psychologically prepared for the morbidity of this procedure (including loss of speech) and a potentially long recovery.

Indications

MT, whether for palliation or for cure, is indicated after tracheal resection, laryngectomy, or laryngopharyngectomy in cases where there is insufficient length of intrathoracic trachea to either reanastomose it superiorly or bring it out suprasternally (Fig. 65-2). This determination depends on various factors, including the patient's anteroposterior diameter (one needs more length in a barrel chest), the effectiveness of tracheal mobilization, and the malleability of the remaining trachea. Some surgeons suggest that the optimal length for MT is greater than 5 cm from the carina.² The procedure also may be indicated in some patients with a cervicothoracic malignancy and “impending airway obstruction.” However, if the disease is unresectable or the patient has significant comorbidities, an airway stent may be more appropriate.

Oncologic Principles

Upper aerodigestive system malignancies severely affect quality of life, and careful consideration must be given not only to cure but also to palliation. The most important oncologic principle is to understand clearly if the goal is cure or palliation. One or two centimeters can change the approach to the procedure. That is, if palliation is the goal, clear margins are not critical, and the additional preserved length may facilitate the procedure. On the other hand, if the procedure is being performed for cure, one must not sacrifice oncologic margin for the sake of tracheal length. Most important, in either case, this procedure must be completed without tension on the anastomosis. Otherwise, neither palliation nor cure may be achieved. Instead, the patient will be at severe risk of complications such as innominate artery rupture or stomal breakdown with mediastinitis.

Preoperative bronchoscopy, esophagogastroduodenoscopy, computed tomography, and magnetic resonance imaging should be done to assess if the operation is technically possible. The surgeon should assess the length of tumor-free trachea distal to the lesion and the involvement of adjacent vital structures. A metastatic workup is necessary and may include a whole-body positron emission tomography scan, bone scan, and head imaging. MT is not contraindicated in patients with metastatic disease if the goal is palliation. However, with metastatic disease, other therapies, such as airway stents or radiation therapy, may be considered. If there are plans to divide the innominate artery, a preoperative arteriogram assessing the patient's cranial perfusion is important. A visceral arteriogram also may be useful in evaluating the blood supply to the colon as an esophageal substitute. In this case, a barium enema and colonoscopy are recommended to assess the colon as an appropriate conduit. Finally, a bowel preparation should be performed if there is any possibility of esophageal substitution.

The intraoperative preparation depends on the surgeon's technical preferences. For surgeons who consider dividing the innominate artery, arrangements may be made for intraoperative electroencephalography after the artery has been clamped. Arterial line monitoring, nasogastric tube drainage, a Foley catheter, and two large-bore peripheral intravenous lines are ideal. Jugular and subclavian lines may interfere with the operative field. Close coordination between the surgeon and the anesthesiologist is required to safely obtain an airway prior to the surgery. Furthermore, after division of the trachea, it is ideal to have the appropriate tracheostomy available. The tracheostomy used for this procedure has a low-pressure, high-volume balloon with a short distance of tubing distal to that balloon.

Positioning, Incisions, and Tracheal Exposure

The patient is positioned supine with the head extended on a cushioned head support and the scapula on a folded blanket. One arm may be abducted for arterial or venous access. A left-sided radial arterial line is ideal if there is any chance of dividing the innominate artery. Sterile preparation may extend from the chin to the pubis and midaxillary line bilaterally. The abdomen is included if esophageal substitution or omental wrapping of the tracheostomy is planned. The thighs may be prepared as well for a potential split-thickness skin graft or vein graft.

The common incisions used for MT are the extended collar incision and the bipedicled/apron incision (Fig. 65-3).^1,2 When the tracheostomy is being performed for a recurrence in the tracheostomy site, the peristomal skin must be resected and a rotational pectoralis flap is necessary (Fig. 65-3C). The preferred incision is the extended collar incision. However, if there is any hint of tension at the tracheocutaneous anastomosis, we perform a rotational pectoralis flap and prepare the thigh for a split-thickness skin graft for the residual defect.

The surgeon's first goal is to assess the appropriateness of the procedure before proceeding with potentially irrevocable actions such as resecting the breastplate. Occasionally, the surgeon may find either that the tumor is unresectable or that tracheal reanastomosis is possible with adequate mobilization.

Using the extended supraclavicular collar incision (Fig. 65-3A), bilateral subcutaneous platysma flaps are created exposing the strap muscles superiorly. The carotid sheaths, sternum, and hyoid bone are exposed. The sternocleidomastoid muscles and carotid sheaths are displaced laterally. Unilateral vessel involvement by tumor is not a contraindication, because they can be divided and reconstructed. The anterior trachea, posterior trachea, and prevertebral fascia are exposed while preserving the important lateral blood supply of the trachea. For tracheal tumors, the prevertebral space is bluntly dissected, ruling out invasion of the vertebral column and the pharynx superiorly. In general, invasion of the larynx and either the esophagus or the trachea within the thoracic inlet necessitates an MT to obtain adequate margins for cure.

Breastplate Resection

The inferior flap is developed after declaring the need for MT. The goal of this flap is to expose the breastplate, including the upper sternum, clavicle, and the first two ribs (Fig. 65-4). The muscular insertions (i.e., straps and sternocleidomastoid) are divided to expose the sternum, clavicle, and ribs. The decision to extend the resection down to the second rib depends on the level of anticipated tension on the tracheocutaneous anastomosis. If there is any doubt, the upper sternum and second rib should be resected.

First, the mammaries are protected and isolated by locating them at the level of the second rib. Next, the midline pectoralis fascia, from the sternal notch to the angle of Louis, is bisected with electrocautery. The pectoralis muscle then is elevated off the first two medial costochondral joints. The sternum is transected transversely just above the third rib. By elevating the sternum with bone hooks, underlying structures can be swept away. The pectoralis flap will be used to cover the wound defect later. The upper sternum and manubrium are bisected with the electric saw. The mammary and subclavian veins are swept clear, and the Gigli saw is used to encircle the first and second cartilages individually and to divide the medial thirds in a subperiosteal plane. Our technique for resecting the clavicle and first rib includes the precaution of sliding a ribbon between the Gigli saw and the subclavian vessels. The sawing sound changes if the “protective” ribbon is encroached. The free breastplate is removed.

Tracheal Division and Laryngectomy

After the breastplate has been removed, the surgeon prepares to divide the trachea. A complete node dissection appropriate to the tumor should be done. The innominate vein is preserved unless invaded directly. The level of tracheal division is determined by considering the margins and whether the goal of the particular surgery is palliative or curative. A Penrose drain may be passed behind the specimen portion of the trachea to facilitate further exposure (Fig. 65-5). Again, attention should be paid to preserving the lateral blood supply of the remaining trachea and stoma (Fig. 65-6, inset). Circumferential devascularization of the trachea (particularly within 1–2 cm of the transected edge) should be avoided to prevent peristomal breakdown and mediastinitis. Prior to division, stay sutures are placed at the inferior tracheal margin. The trachea is divided obliquely at the inferior margin. This facilitates the tracheocutaneous anastomosis such that it may curve anteriorly flush with the skin (Fig. 65-5, inset). After division, it is reintubated (Fig. 65-6) with sterile tubing across the field. The tracheostomy tube is secured with stay sutures to the trachea and to the skin. To preserve the airway, the inferior division is dealt with first. Next, the superior division usually is made at the level of the thyrohyoid membrane, preserving the hyoid bone. The larynx then is oversewn with running sutures. Total or partial thyroidectomy may be required depending on the extent of tumor involvement. All efforts should be made to preserve a parathyroid, with reimplantation if necessary. If there has been prior radiation, however, this may be difficult.

Transposition of the Trachea

Tension on the trachea as it reaches the anterior chest wall and skin may result in complications, including peristomal breakdown leading to mediastinitis and even fatal postoperative innominate artery rupture. For this reason, if there is any doubt, we and other authors strongly recommend transposition.^2,3 The standard MT will rest interposed between the innominate artery and the left carotid artery (Fig. 65-7). With transposition, the trachea will follow a shorter path to the skin by coursing to the right of and underneath the innominate artery. Thus, its path lies between the innominate artery and the superior vena cava (Fig. 65-8). Although we do not recommend it, innominate artery division is another option for patients who can tolerate it (Fig. 65-9). This can be demonstrated with preoperative angiogram or even intraoperative electroencephalogram after clamping for 10 minutes. It may be best suited when the distance from the carina to the end of the remnant trachea is less than 5 cm.¹ After transposition, we recommend wrapping the trachea as it passes underneath the artery with a well-vascularized strap muscle. Other options include omentum or pectoralis muscle. The most important factor, however, is that the trachea is well vascularized and reaches the skin without any tension. Wrapping the trachea will not prevent arterial rupture if there is significant tension.

Tracheocutaneous Anastomosis and Closure

The route of the trachea to the anterior skin must be secured, wrapped, and buttressed by all available tissue. With the exception of the specific strap muscle that protects the innominate artery (in tracheal transposition), all muscles should be reapproximated with interrupted absorbable sutures. As the cervical incision is sutured closed, the tracheocutaneous anastomosis is begun. It must be secured to the skin with full-thickness skin and subcutaneous purchases as well. This is done in an interrupted fashion (Fig. 65-10). A few absorbable sutures may be placed from the subcutaneous tissue to distal trachea to reduce the tension on the tracheocutaneous anastomosis.¹ Drains are placed beneath the inferior and superior flaps and for any alimentary tract anastomoses. If there is a defect in the apron incision, a split-thickness skin graft can be used for coverage (Fig. 65-11).

At this point, if there appears to be any tension, there are several options. A button of skin can be excised below the transverse incision, and the trachea can be brought out through this new defect.² In this scenario, we prefer to use the pectoralis rotational flap. Development of the pectoralis flap began when it was lifted off the chest wall before the breastplate resection. This thoracoacromial “nipple” flap (Fig. 65-12) can be done, even in patients without a tracheostomal recurrence.

Rotational Flaps

A thoracoacromial flap is used most often in a patient with laryngeal cancer who suffers recurrence at the stoma site. In these patients, the surrounding skin is resected (Fig. 65-3C). However, it also may be performed after a standard extended collar incision if there is tension at the end of the case. Simply extend the incision inferiorly along the sternum and around the inframammary crease (Fig. 65-3C) to the preferred side. Both pectoralis muscles will have already been lifted off the chest wall in the prior dissection. The rotated muscle is based on the thoracoacromial vessels. A split-thickness skin graft can cover the remaining defect (Fig. 65-12).

As with any surgery, postoperative care is very important to a successful outcome. As a unique airway, this surgery requires special attention. ICU care is required for all of these patients at least until postoperative day 1 or 2. Many will be mechanically ventilated if they have undergone a more extensive procedure, such as esophagectomy or cervical exenteration. However, patients undergoing MT only will be weaned off mechanical ventilation early in the postoperative period. All should have continuous oxygen saturation monitoring. Some surgeons also recommend warm mist treatments through a tracheal collar to moisturize the tracheal mucosa.⁴ Flexible endotracheal tubing (that extends from the tracheostomy) should be secured overhead with ties, not resting on the wound or skin graft. The tracheostomy tube is sutured to the end of the trachea at the time of distal tracheal division. The nursing staff must be familiarized with the location of the balloon just within the stoma, and balloon pressures should be monitored. Ideally, a low-pressure, high-volume balloon is used.

Postoperative studies include a chest x-ray to check nasogastric tube position and the tip of the short portion of tracheostomy tube. Functional nasogastric tube decompression is imperative, especially if the patient has had alimentary continuity restored. Aspiration of gastrointestinal contents can be devastating and is common with the unprotected trachea's new position relative to the mouth. Serial calcium determinations should be done in the case of parathyroidectomy.

There are various unique and not-so-unique complications with this procedure. Of course, the most devastating is innominate artery rupture. This must be treated with prevention. The importance of creating a tension-free path of the trachea to skin via the innominate artery and aortic arch cannot be overemphasized. Another particular complication is the anterior flail segment (also referred to as lung herniation) from the breastplate resection.⁴ For this reason, preoperative respiratory exercises and smoking cessation should be encouraged. Peristomal breakdown also can occur secondary to tension or paroxysmal coughing fits. Depending on adjunct procedures performed, other complications to watch for are hypoparathyroidism, hypothyroidism, perioperative stroke, anastomotic leak, cervical chyle leak, arm swelling (secondary to subclavian vein displacement), and dumping syndrome (secondary to vagus division in esophagectomy).

Perioperative morbidity and mortality are disease- and procedure-specific with regard to MT. In 1996, Orringer reported a 13% mortality in 45 patients. One death was due to innominate artery rupture. He also recorded a secure airway in 100% of patients.² Orringer's patient population consisted of 35 patients who underwent MT with concomitant cervical exenteration and esophageal substitution. Grillo and Mathisen reported one perioperative mortality in their series of 18 cervical exenterations with MT. This occurred secondary to ischemic necrosis of the stomach graft used to replace the esophagus.¹ With regard to loss of speech, some of these patients may learn a form of “esophageal speech” or artificial speech with the latest electrical appliances.

The MT is a radical procedure that must be performed judiciously. Although, airway security is achieved in almost every case, patients experience a high frequency of complications. Prevention of these complications, in particular, innominate artery rupture, can be achieved through different methods. Until a safe and reliable replacement for the trachea is found, this will continue to be a palliative, curative, and emergency lifesaving procedure.

Careful preoperative imaging and multidisciplinary discussions among the thoracic surgeon, otolaryngologist, plastic surgeon, and vascular surgeon are helpful. On occasion, the omentum can be brought up substernally and used to cover the vessels and wrap the tracheostomy. Today, the most common indication for this operation is failure of chemoradiation treatment for a laryngeal or proximal esophageal cancer. Although such treatments are generally efficacious, patients should be carefully monitored to identify recurrences early enough for action. Medical and radiation oncologists are not sufficiently aware of this surgical option until it is too late as a result of local invasion or metastatic disease—one reason why surgical follow-up is important even when originally the therapy proposed is nonsurgical. If division of the innominate artery is contemplated, consideration should be given to potential bypass to ensure the blood supply to the brain.