Tracheostomy

ANATOMY

The trachea is about 10 cm long and 2 cm in diameter and extends from the larynx at the level of the sixth cervical vertebra to its bifurcation into two bronchi at the level of the fourth thoracic vertebra. It is composed of numerous incomplete cartilaginous rings that are united posteriorly with membranous tissue to form the membranous portion of the trachea.

Anteriorly, the pretracheal fascia, the isthmus of the thyroid gland, and the infrahyoid strap muscles cover the trachea. The esophagus lies posterior to the trachea, with the recurrent laryngeal nerve situated in the tracheoesophageal groove. The common carotid artery laterally, inferior thyroid artery superiorly, and esophagus medially form Simons triangle. The lateral relations of the trachea are the lateral lobes of the thyroid gland, the inferior thyroid artery, and the carotid sheath with its contents.

The blood supply of the trachea is from the inferior thyroid vessels, and its lymphatic drainage is to paratracheal lymph nodes.

Operative Technique

POSITION

The patient is placed in the supine position, and the neck is extended with a shoulder roll. General anesthesia is administered with endotracheal intubation. The neck and upper thorax are prepped and draped in the usual fashion.

INCISION

Approximately two fingers-breadth above the suprasternal notch, a 4- to 6-cm transverse incision is marked.

Figure 3-1 A, The transverse incision is shown in relation to the underlying bony structures. B, After the thyroid isthmus is retracted superiorly, the tracheostomy tube is inserted with the assistance of the tracheal retractor.

EXPOSURE AND OPERATIVE TECHNIQUE

An incision is sharply made and carried through the subcutaneous tissue and the platysma. Self-retaining Weitlaner retractors are placed longitudinally and transversely. The midline cervical fascia is identified and divided longitudinally. The anterior jugular veins are avoided if possible; if necessary they are ligated in continuity with 3-0 silk sutures and divided. Next, the underlying sternothyroid is also retracted laterally with two Army-Navy retractors. Dissection should be kept in the midline heading directly toward the trachea. If the thyroid isthmus lies over the second or third tracheal ring, it can be either retracted upward or divided. Division of the isthmus is often needed, where the thyroid tissue is dissected with a Mixter right-angle clamp, divided, and transfixed with 2-0 silk suture ligatures. To maintain exposure, the two Weitlaner retractors are repositioned as the dissection proceeds toward the trachea.

The thyroid cartilage notch and more inferiorly the cricothyroid membrane and the cricoid cartilage are identified. The second and third tracheal rings are identified and marked lightly with electrocautery. Before opening the trachea, ensure that a suction catheter is available. Also ensure that the tracheostomy cuff is intact and well lubricated. A cruciate incision is made sharply between the second and third tracheal rings, and the edges are separated with a tracheal retractor. Placing the tracheostomy more inferiorly can increase the risk of pressure on the innominate artery and thus the risk of tracheoinnominate fistula. The surgeon must also be aware of the presence of the thyroid ima artery (in 13% of patients) arising from the aortic arch and of the thyroid ima vein (in 13% of patients) draining into the innominate vein to avoid iatrogenic injury to these vessels.

After placement of the tracheostomy, the anesthesiologist is requested to withdraw the endotracheal tube, and the tracheostomy tube is gently slipped into the trachea. The end of the tracheal tube is completely withdrawn, and the ventilator is connected to the tracheostomy after the blunt obturator is removed. Mucus should be suctioned from the tracheobronchial tree.

CLOSURE

Secure the flange of the tracheostomy to the skin with four corner sutures using 3-0 monofilament sutures. Because the skin incision is usually small, only one or two interrupted 4-0 monofilament sutures are required to approximate the skin. To further secure the tracheostomy, a narrow umbilical tape is placed loosely around the patient’s neck and attached to the tracheostomy flange. A gauze dressing is placed at the side of the tracheostomy.