Tracheal resection is performed most commonly for benign disorders. The primary indication is fibrotic stenosis, whether idiopathic, traumatic, or postintubation. Occasionally, tracheal resection is indicated for neoplastic disease or short-segment malacia.

Patients usually present with shortness of breath, which occurs initially only on exertion but in more advanced cases it may even occur at rest. There is often a history of treatment with numerous bronchodilators or steroids for presumed asthma. Occasionally, previous endotracheal intubation or tracheostomy has prompted imaging studies and an earlier referral to a thoracic surgeon. It is important in the history to delve into any previous airway interventions, such as tracheostomy, previous intubations, as well as previously diagnosed malignancies, especially of the head and neck. On examination, patients generally are comfortable at rest but manifest stridor, which usually is inspiratory in nature but occasionally expiratory. Even with severe tracheal stenosis, patients still may have acceptable oxygen saturation. Symptoms usually do not manifest until there is quite a significant degree of stenosis, on the order of a residual 5-mm lumen.

Imaging is a necessary part of the preoperative preparation. Except for patients with acute airway compromise, imaging studies always can be done before the endoscopic assessment or operative intervention. Detailed CT scans of the neck and chest are performed routinely (Fig. 57-1), with three-dimensional reconstruction, if possible (Fig. 57-2). These studies aid in planning for airway management and endoscopic assessment and warn of possible surprises, such as severe distal tracheal or bilateral proximal bronchial stenoses, which may not show on x-rays.

Except for the extremely fragile patient, most will be able to tolerate a tracheal resection if it does not require a thoracotomy. The endoscopic assessment therefore is pursued with a possible resection foremost in mind. This evaluation should be performed independent of surgery because repeat dilations of cicatricial stenoses can delay or obviate the need for surgery altogether.

The bronchoscopy should be conducted in the operating theater, with both flexible and rigid bronchoscopes of varying sizes available, as well as dilators and equipment for tracheostomy or tracheal-tube (T-tube) insertion. The questions to be answered include:

1. 
   

   Should this lesion be managed by resection or by more conservative means?

   
   
2. 
   

   Is the lesion amenable to a tracheal resection?

   
   
3. 
   

   What surgical approach will be needed for the level and length of this lesion?

   
   
4. 
   

   Can we proceed safely with surgery, or should we allow some time for resolution of inflammation?

Benign fibrotic stenoses may be managed initially by periodic dilation, but if the frequency of dilation necessary to relieve symptoms becomes unacceptable, a resection should be performed. Naturally, for neoplastic disease, resection should be considered as soon as the diagnosis is made. Tracheal resections are always done electively and should be well planned. If the stricture is secondary to intubation or trauma, enough time should be given for the scar to stabilize and assume its final length, a period of 3 to 6 months. If the initial bronchoscopy shows significant inflammation, which is often due to pooling of infected secretions beyond a point of obstruction, the obstruction should be relieved by dilation or bypassed by a tracheostomy or T-tube. In all instances, inflammation should be reduced to the lowest achievable level to avoid anastomotic complications. Oral steroids have been used occasionally to reduce inflammation (but should be reduced in dosage prior to surgery). In the unusual situation where the obstructing neoplasm cannot be bypassed with a tracheostomy, the difficult decision must be made whether to proceed with tracheal resection in the presence of a tracheitis or first core out the tumor. We favor the latter approach rather than risk an anastomotic disruption.

Position

In most situations, the patient is placed supine with the neck hyperextended and a deflatable shoulder bag in place. Arms may be tucked in or abducted. If abducted, 45 degrees is preferable so that the surgeon can stand above or below the arm.

Endoscopy

The surgery always should begin with a full endoscopic assessment, including assessment of vocal cord function and measurement of the length of the lesion. The choice of incision and type of operation depend predominantly on the level and length of the lesion.

Airway Management

Orotracheal intubation is the usual manner of airway control, with dilation as needed to accommodate the usually small (6 mm or so) endotracheal tube. If the stenosis is high grade and cannot be dilated, there is usually a tracheostomy or T-tube present. The existing tube is removed, and an armored, cuffed endotracheal tube is inserted into the stoma and prepped into the field. This tube can be replaced later by a sterile tube and anesthesia tubing, once draping is complete.

Surgical Approach

Upper and midtracheal lesions can be approached via a low-collar incision, occasionally with the addition of a partial sternal split (Fig. 57-3). For lengthy lesions, the original incision should be extended. There are a number of possibilities, including a full median sternotomy, unilateral extension of a partial or full sternotomy into a fourth interspace thoracotomy, or a bilateral thoracosternotomy (clamshell) incision. If the lesion is complicated enough to require intrathoracic mobilization, we favor the clamshell incision to permit bilateral hilar release as well as mobilization of the inferior pulmonary ligaments. This approach, that is, neck incision plus clamshell, permits management of all except low tracheal and carinal lesions, which are best handled through a right posterolateral thoracotomy from the start. The transpericardial approach for a carinal resection, however, is quite feasible via a clamshell or median sternotomy.

Dissection

The neck incision is similar to that used for thyroidectomy but shorter because the lateral and superior dissection is less extensive. If there is a stoma, this should be circumscribed. Subplatysmal flaps are raised to expose the trachea from the level of the lower thyroid cartilage to the sternal notch. Strap muscles are separated in the midline and retracted. If both stoma and endotracheal tube are present, all dissection is begun distant to this site, in a region with recognizable planes. The surgery then proceeds toward this usually inflamed and fibrotic area, and all pretracheal and peristomal tissue is excised. The thyroid isthmus is divided in the midline, and the edges are suture-ligated. The thyroid lobes then are dissected away from the trachea, taking care that sharp dissection is used in the plane immediately next to the trachea to avoid injury to the recurrent laryngeal nerves. Since these nerves travel upward in the tracheoesophageal groove before they enter the larynx at its posterolateral aspect, extreme care should be taken in this area, and dissection should stop short of their usual location. In general, the nerves should not be deliberately exposed as long as one follows the technical principle of maintaining the dissection close to the trachea.

Once the trachea is exposed, the lesion is evaluated carefully. Mobilization of the anterior trachea is done by blunt finger dissection in the pretracheal space, similar to the technique used for cervical mediastinoscopy. Careful dissection in the tracheoesophageal groove then is accomplished to separate the trachea from the esophagus, and again, the finger is used to bluntly dissect the posterior tracheal plane downward into the mediastinum. It is of vital importance in tracheal surgery to limit these dissections to the anterior and posterior planes to preserve the lateral tracheal connective tissue because the tenuous blood supply to the trachea occurs mostly via laterally located branches (Fig. 57-4).¹ Circumferential dissection of the trachea should be done only at the level of the lesion and 1 to 2 mm beyond the planned margins of resection. These maneuvers should mobilize the trachea adequately so that it can be evaluated for extent of the lesion. Both external and endoscopic assessments should be done. The flexible bronchoscope is inserted through a partially withdrawn endotracheal tube, and using a small needle inserted through the anterior tracheal wall, the proximal and distal extents of the lesion are identified. All gross evidence of external and internal abnormalities should be resected. If a stoma is present, the bronchoscope still should be passed from above through the glottis, and the endotracheal tube in the field should be removed as needed for accurate evaluation. If possible, as it usually is, the stoma is resected along with the lesion.