Tracheal Resection

Tracheal resection with primary reanastomosis for tracheal tumors and stenosis is a well-described procedure.[1, 2, 3, 4]  It is most commonly indicated for postintubation lesions but is also performed for malignancies, secondary tracheal tumors, and tracheoesophageal and tracheal innominate fistulas. Approximately half of the trachea can be safely removed with a low incidence of anastomotic complications.[2, 3, 4, 5]

Because of the lack of suitable replacement material for the trachea, various mobilization and release maneuvers have been demonstrated to increase the length of the tracheal resection by elevating the carina. These include hilar, suprahyoid, and suprathyroid laryngeal release[2, 6, 7] ; anterior and posterior digital tracheal dissection; and constant neck flexion. Research into the use of bioprosthetic materials for tracheal replacement is ongoing.[8]

Constant neck flexion by a suture between the skin of the point of the chin and midline of the chest over the manubrium has been widely considered paramount for successful tracheal resections. An orthosis has also been used as a more comfortable alternative to utilizing the traditional suture between the chin and the midline of the chest over the manubrium.[9] The use of tracheal retention sutures on the proximal and distal-lateral edges of the anastomotic line has also been suggested as an alternative to the traditional chin suture for reducing tension on the anastomosis.[10]

Thoracoscopic and robotic-assisted tracheal resections, though not as common at present, have also been described.[11, 12]

Postintubation lesions are the most common indication for tracheal resection and reconstruction. Malignancies (including, predominantly, squamous cell carcinoma and adenocystic carcinoma) also remain an indication for resection.[13, 14] Other indications include secondary tracheal tumors and tracheoesophageal and tracheal innominate fistulas.[15]  (See the images below.)

Contraindications for tracheal resection and reconstruction include the following:

• Medical contraindications for such extensive surgery
• Impaired pulmonary function - A careful evaluation of pulmonary function, if lung resection is to be included, is mandatory and should include spirometry and possibly quantitative ventilation-perfusion scans
• Problematic anatomy - For a right carinal pneumonectomy (the most common carinal resection), the distance from the right distal tracheal margin to the proximal medial left mainstem should not exceed 4 cm in most cases; resections that exceed this are likely to result in excessive anastomotic tension
• Prior irradiation - This is a relative contraindication and should be accompanied by some type of flap, including pleural, intercostal muscle, or omental wrapping ^[16]
• Tracheal resection of over half the trachea ^{[2, 3, 4]}

Anatomy

The trachea is nearly but not quite cylindrical and is flattened posteriorly. In cross-section, it is D-shaped, with incomplete cartilaginous rings anteriorly and laterally, and a straight membranous wall posteriorly. The trachea measures about 11 cm in length and is chondromembranous. This structure starts from the inferior part of the larynx (cricoid cartilage) in the neck, opposite C6, and extends to the intervertebral disk between T4 and T5 in the thorax, where it divides at the carina into the right and left bronchi.

For more information about the relevant anatomy, see Trachea Anatomy.

Johnson et al analyzed 2014-2016 data from the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) to determine perioperative outcomes for 126 patients who underwent tracheal resection or tracheoplasty.[17] Such outcomes included length of stay (LOS), dehiscence, unplanned reintubations, unplanned surgeries, and 30-day readmission rates. The median LOS was 7 days. Six patients (4.8%) developed wound infections, and three (2.4%) developed wound dehiscence. Five (4.0%) required unplanned reintubation, and 16 (13%) had an unplanned reoperation. The 30-day unplanned readmission rate was 16% (20/126).

In a systematic review of 37 studies that included 656 patients with locally advanced thyroid cancer treated by means of (crico-)tracheal resection with primary anastomosis ([C]TRA), Piazza et al found a 2.0% risk of perioperative mortality and a 27.0% surgical complication rate.[18]  A permanent tracheotomy was required in 4.0% of patients. Oncologic outcomes varied, with 5-year overall survival rates of 61-100%, 10-year overall survival rates of 42.1-78.1%, 5-year disease-specific survival rates of 75.8-90%, and 10-year disease-specific survival rates of 54.5-62.9%. 

Equipment needs include the following:

• Operating table
• Thoracotomy tray
• Endotracheal (ET) tubes in multiple sizes 
• Capacity to institute jet ventilation if needed
• Ability to place the patient on extracorporeal membrane oxygenation (ECMO)
• Rigid bronchoscope with dilators and laser for possible dilation before resection
• Bean bag, pillows, and cushions to allow proper positioning

Anesthesia

Tracheal resections typically requires general anesthesia (though alternative approaches have also been employed[19, 20] ). An arterial line and, often, a central line are also useful for the procedure. Airway control is critical for tracheal resections, and intubation should not be taken for granted. If the lesion is critical, maintaining a sedated and breathing patient while passing an ET tube past the stenosis can avert sudden respiratory arrest.

Ventilation during resection of the stenosis can be maintained via an ET tube passed into the operative field. This is placed beyond the stenosis after the trachea is transected. Additional options include jet ventilation or hyperventilation with periods of apnea. Rarely, ECMO with cardiopulmonary bypass must be established before or during intubation.[21, 22]  This modality can allow tracheal resection to be performed before an airway is established. Most patients are extubated in the operating room (OR) and monitored postoperatively in the intensive care unit (ICU).

Positioning

For cervical resection and intrathoracic tracheal resection via sternotomy, the patient is placed in a supine position with a towel roll placed horizontally under the shoulders.

For intrathoracic tracheal resection and right tracheal sleeve pneumonectomy via right thoracotomy, the patient is placed in a posterolateral thoracotomy position with the right chest at approximately 90º off the horizontal. Appropriate cushions and a bean bag are used to aid in positioning and to help prevent injury.

For cervical lesions, a horizontal neck incision is used, occasionally accompanied by a median sternotomy or ministernotomy. Intrathoracic lesions can be addressed via a sternotomy (the author’s preference) or a right thoracotomy. Right tracheal sleeve pneumonectomies are done via a right thoracotomy, whereas left tracheal sleeve pneumonectomies are done via a combined approach or via a thoracosternotomy ("clamshell" incision), though some have abandoned this operation.

Tracheal resection is depicted in the videos below.

A neck incision, ministernotomy, or full sternotomy is performed as indicated by the level of tracheal stenosis. The strap muscles are retracted or incised for cervical stenosis, and the innominate artery, superior vena cava (SVC), innominate vein, and pulmonary artery are retracted for exposure to the distal trachea. Operative dissection is performed directly on the trachea and associated scar tissue to avoid injury to the lateral blood supply and recurrent laryngeal nerves.

Circumferential dissection of the trachea is confined to the area of stenosis along with no more than 1-2 cm of normal trachea above and below the stenosis. This method of detailed dissection preserves the lateral segmental blood supply of the trachea. Most cervical trachea disease can be approached through a low collar incision or a collar incision combined with an upper partial sternotomy. If a stoma is present, then it is usually incorporated into the collar incision; however, if it is higher than normal, then it can be excised and closed separately.

Subplatysmal flaps are elevated to the thyroid notch superiorly and the sternal notch inferiorly. The strap muscles are saved and retracted laterally or incised with electrocautery. The thyroid isthmus is divided and reflected laterally. Mobilization of the trachea is performed only on the anterior surface before resection from the cricoid to the carina.

The level of the stenosis is determined on the basis of the extrinsic anatomic deformity of the trachea or by means of intraoperative bronchoscopy with transillumination of the trachea and inspection with a needle placed through the stenosis. Circumferential dissection is carried out directly at the stenosis to minimize injury to the nerves and maintain the segmental blood supply. The trachea is first divided below the stenosis in an area of normal trachea, and dissection is carried proximally to free up the esophagus posterior to the trachea.

The trachea is divided proximally, and after the stenotic segment is removed, cross-field ventilation via the operative field is achieved in the distal trachea. Stay sutures are placed laterally two rings above and below the planned resected segment, and with neck flexion of the patient, assessment of the tension on the completed anastomosis is carried out.

Cervical neck flexion and anterior mobilization to the carina will allow, in most cases, a tension-free anastomosis of the cervical trachea. If additional length is required, a suprahyoid laryngeal release can be performed via the Montgomery technique and neck flexion performed for approximately 1 week postoperatively.

A standard right posterolateral thoracotomy is performed. The initial dissection is commenced by division of the azygos vein to expose the carina. The distal trachea and the right and left mainstem bronchi are encircled. Initial conservative incision into the distal trachea is guided by flexible bronchoscopy through the oral endotracheal (ET) tube.

The technique for airway reconstruction is the same, regardless of the level. Traction sutures are placed in the midlateral position of the proximal and distal airway to be reconstructed. These sutures are used to assess the extent to which the airway can be approximated. If excess anastomotic tension is thought to exist, release maneuvers may help reduce tension on the anastomosis. Division of the pulmonary ligament and hilar release accomplished by dividing the pericardium circumferentially around the hilum provide an additional 1-2 cm of mobility to the distal airway.

Suprahyoid release may also be used but may not add much additional length for carinal resection procedures. Once the determination has been made that the airway can be reapproximated, individual anastomotic sutures (4-0 polyglactin) are placed circumferentially. All sutures are placed in such a way as to allow the knots to be on the outside of the anastomosis. Once the back row of sutures is tied, the table neck is flexed, the operative field ET tube is removed, and the oral ET tube is advanced onto the left mainstem bronchus beyond the anastomosis.

The front row of sutures should then be tied and the ET tube withdrawn to the trachea proximal to the anastomosis. When all of the sutures have been tied, the anastomosis should be checked to confirm that it is airtight. The anesthesiologist ventilates the patient to 20, 30, and 40 cm of pressure. The operative field is submersed in saline to allow identification of any leaks. Any anastomotic leakage must be addressed—by repair if possible or, if repair proves impossible, by taking the entire anastomosis apart and starting all over.

Once the anastomosis has been secured, soft-tissue coverage of the anastomosis is achieved with a pedicled flap of pericardial fat, pleura, or intercostal muscle. Inspection of the anastomosis with bronchoscopy is performed before the patient is extubated. Frozen section to confirm complete resection for tracheal tumors is also generally indicated.[16, 23, 24, 25, 15]

Potential complications of tracheal resection and reconstruction include the following: 

• Bleeding
• Infection
• Airway edema
• Pulmonary insufficiency
• Anastomotic dehiscence
• Anastomotic fistula
• Tumor recurrence
• Anastomotic stenosis
• Anastomotic leakage

Hyperparic oxygen therapy (HBOT) has been suggested as a potentially useful adjunct in the management of anastomotic problems after airway surgery.[26]