INDICATIONS

It is generally agreed that the maximum length of tracheal resection that can be repaired by end-to-end anastomosis is 6 cm. Primary tracheal neoplasms (including adenoid cystic carcinomas [ACCs], squamous cell carcinomas [SCCs]) and other tracheal diseases can be usually managed by tracheal resection with primary anastomoses. However, there are diseases that require resection of segments of trachea longer than 6 cm also requiring reconstruction with a tracheal substitute.

Tracheal replacement for disease invading 6 to 12 cm of the trachea can be performed with the use of reliable autologous free fasciocutaneous flaps in combination with autologous cartilage struts. Previously, circumferential resection with release procedures (suprathyroid or suprahyoid laryngeal release) and direct anastomosis must be considered before this procedure. The most reliable flap for this reconstruction is the forearm free flap that could replace the entire membranous wall of the trachea for extended tracheoesophageal fistulae (TOF). Reinforced with cartilage ribs this autologous tracheal substitution (ATS) using the forearm free flap can replace the entire trachea from the cricoid cartilage to the carina. Indications are primary tracheal neoplasm (including ACC and SCC), secondary tracheal neoplasm (thyroid carcinoma, thymic carcinoma, etc.) and extended TOF (postintubation tracheal destruction, tracheal necrosis after lymphoma, etc.). Benign and malignant neoplasms have to be discussed by a multidisciplinary team before surgery.

CONTRAINDICATIONS

Determination of Resectability

Tracheal resection was considered when complete resection of gross airway disease appeared feasible. An Assessment of locoregional and distant metastatic disease has to be performed before resection. Preoperative radiation therapy is associated with a higher incidence of complications but is not a contraindication for ATS. Bronchoscopy has to be performed before resection to assess the presence and extent of luminal invasion. Patients with SCC and N2 disease should be contraindicated for ATS. N2 disease is assessed using preferentially EBUS, EUS, or mediastinoscopy. Bilateral recurrent nerve involvement is most of the time an indication for laryngectomy. Involvement up to the cricoid or thyroid cartilage and extended esophageal involvement are considered as contraindications to this extensive and difficult surgery. But a partial laryngotracheal resection could be performed in few cases. On bronchoscopy, the lengths of involved airway define the length for tracheal reconstruction that is limited to 12 cm. Tracheal tumor extension up to the carina and extended esophageal invasion are currently a contraindication for ATS. Indeed, the main limitation of the neotrachea is the absence of mucociliary clearance because its inner aspect is covered by a squamous epithelium. The quality of the mucociliary clearance is correlated to the resection length. We currently do not recommend this technique to treat lesions that extend to the main bronchi and for patients with pulmonary and diaphragmatic dysfunction of sufficient magnitude to interfere with effective coughing. The other limits of this technique are also chronic respiratory insufficiency and cartilage calcifications (risk of cartilage fracture).

PREOPERATIVE PLANNING

Patient Selection

Because of the high risks of this surgery a careful preoperative assessment of each patient is required. Ethics approval should be granted by the Ethics Board and individual patient consent should be obtained. For neoplasms, a multidisciplinary consultation (including thoracic oncologist and thoracic surgeon) before surgery is needed to confirm the indication for ATS. Patients with an extended primary tracheal neoplasm, a secondary tracheal neoplasm, or an extended tracheal destruction are the main indication for this ATS. Indication for ATS in case of ACC with lung metastasis should be carefully weighted by the actual results of radiation therapy.

Patients should be carefully screened from a general medical point of view. The age, sex, histology, preoperative medical history, pulmonary function test, performance, laboratory tests, tumor location, vocal cords function, and cardiac function should be carefully assessed. The diagnostic staging modalities included bronchoscopy, computed tomography (CT) scanning, and positron emission tomography-computed tomography (PET-CT). Echocardiography and stress thallium are used when indicated. Angiography of supra-aortic arteries should be performed to warrant the patency of the donor vessel for microvascular anastomosis of the free flap. Furthermore, involvement and patency of the supra-aortic arteries has to be assessed before surgery. Allen’s test must be performed on both sides (the color of the hand should return to normal in 7 seconds) to confirm the possibility for forearm free flap harvesting. Predicted postoperative forced expiratory volume in 1 second should be more than 70%. Indeed, respiratory failure is a contraindication for ATS due to the increasing pressure on the neotracheal wall during inspiratory depression. Indeed, respiratory insufficiency can lead to late cartilage fracture inserted between the dermal layers of the free flap.

SURGERY

The patient is positioned supine, anesthetized and intubated with a single-lumen endotracheal tube and then prepped and draped in the usual fashion. With a warming system, a pillow is placed transversally in the back at the middle of the sternum. An inflatable bag beneath the patient’s shoulders (“thyroid bag”) is very useful and could be deflated, giving a measure of cervical flexion. For this long operation two teams of surgeons are working together. The entire chest and entire neck is prepped with a chlorhexidine–alcohol solution and then draped with sterile towels and sheets. For the forearm free flap harvesting, the chosen arm should be placed on an arm table usually placed at 90 degrees. ATS is performed by an open approach through a transverse cervicotomy with a median vertical sternotomy. The groin and one thigh should also be placed in the operative field. The groin could be used for cannulation and one of the thighs should be prepared for skin graft on the harvested arm. Cartilage harvesting is usually performed on the opposite site from the free flap harvesting.

The first part of the surgery is the tracheal resection including firstly determination of local resectability. After this part performed by the thoracic team, the reconstruction team can start the flap harvesting. During this, cartilages could be harvested on the contralateral side. Usually, the operating thoracic surgeon stands on the right side of the patient while the assistant is on the contralateral side. The operating plastic surgeon stands on the opposite side if the forearm free flap is performed on the left side.

Tumor Resection

Before completing the construction of the neotracheal conduit, the damaged trachea is approached by cervicotomy and median sternotomy. The diseased trachea is resected on healthy margins and the autologous conduit sutured to the native tracheal stumps (i.e., to the tracheobronchial bifurcation below and to the larynx above). If necessary, in addition to removing the trachea, partial resection of the esophagus and removal of one of the recurrent nerves and possibly of the adjacent vascular structures may be needed. During this stage of the procedure, respiratory gas exchange is provided by ventilation with an intubation tube inserted into the bronchi through the surgical field. Alternatively, extracorporeal circulation (ECC) between the right atrium and the ascending aorta can be instituted.

ATS Construction

The neotracheal conduit is constructed from a large, rectangular fasciocutaneous flap harvested from the patient’s forearm (Fig. 42.1

Stay updated, free articles. Join our Telegram channel

Join