Figure 63-1 demonstrates the common technique of cricotracheal resection for circumferential subglottic stenosis. This technique is described not only for use by surgeons wishing to resect stenoses but also for those wishing to excise tumors of the subglottis, as demonstrated in Figure 63-2. In most cases of subglottic tumor resection, the mucosa and submucosa overlying the posterior plate of the cricoid needs to be resected. In some amenable tumors, partial vertical height of the cricoid must be resected to obtain suitable margins, preserving enough posterior cricoid cartilage superiorly and between the arytenoids to preserve arytenoid stability. If the mucosa is resected up to the interarytenoid area, or if a limited margin exists inferior to the true vocal fold, laterally hindering normal vocal fold movement, a laryngofissure is created not only to permit adequate exposure but also to incorporate the use of a stenting T-tube around which healing occurs, preventing postoperative glottic stenosis (Fig. 63-3).
A. Circumferential stenosis of the subglottis and superior trachea. Dashed lines represent the external extent of resection. A lateral transection through the cricoid lamina allows removal of the anterior cricoid arch while preserving the posterior cricoid lamina, thereby protecting the recurrent laryngeal nerves. A posterior membranous tracheal wall flap is formed distally. B. The superior line of resection is through the cricothyroid membrane, curving inferiorly through the lateral cricoid laminae. The first preserved tracheal ring is shaped into an inverted U for anastomosis directly to the thyroid cartilage. If a longer posterior flap is required for reconstruction, the level of tracheal resection may be dropped by an additional ring. C. The internal line of resection (dotted line) removes the stenosis involving the posterior cricoid lamina. With neoplasms that involve the cricoid, the posterior lamina may be resected, but the posterior perichondrium and a superior horizontal strut of cartilage should be preserved to maintain arytenoid stability and posterior muscular attachments. D. The denuded posterior lamina of the cricoid is covered with the membranous flap from the posterior trachea. The first tracheal ring is shaped to fit the inferior thyroid cartilage resection line. E. 4-0 Vicryl is used internally to close the mucosal defect over the posterior cricoid lamina. 3-0 Vicryl suture is used to anastomose the tracheal ring to the thyroid and cricoid cartilages and to anchor the base of the membranous flap to the posterior cricoid cartilage, taking care not to injure the recurrent laryngeal nerves. All knots are tied outside the lumen. F. The superior trachea is anastomosed to the thyroid cartilage with 3-0 Vicryl sutures. The most superior tracheal ring has been formed into an inverted U for best fit into the laryngeal defect. Laterally, the cricoid is approximated to the second tracheal ring to minimize the tension on the first preserved tracheal ring.
A. An endolaryngeal tumor occupies the posterior subglottis. The anterior cricoid is separated from the thyroid cartilage in a similar manner as in cricotracheal resection for stenosis. The inferior tracheal resection is performed at a level that obtains a negative margin on the tumor. Lastly, the superior tracheal rings and cricoid arch are divided in the midline for optimal tumor visualization. B. Superior and inferior margins are obtained on the tumor. If the posterior cricoid lamina is involved, the cartilage may be resected, but the posterior perichondrium and a strut of cartilage superiorly upon which the arytenoids articulate must be preserved for stability. Additional tracheal rings may be resected to elongate the posterior tracheal flap. C. Reconstruction occurs in an identical manner as in stenosis treatment. The denuded posterior cricoid cartilage is covered by the posterior tracheal flap and approximated to the remaining superior mucosa. The first tracheal ring fits like a prow of a ship into the defect of the anterior cricoid arch.
A. Negative mucosal margins are obtained, with optimal visualization achieved via the laryngofissure. Despite the tumor being superficial, partial thickness of the cricoid cartilage is drilled for an additional deep margin. As much of the interarytenoid mucosa is preserved as possible to maintain arytenoid mobility. B. The trachea is advanced into the defect, with the posterior membranous flap approximated directly inferior to the true vocal folds with interrupted 4-0 Vicryl. Less violation of the interarytenoid mucosa is desirable, although postoperative stenting assists in decreasing posterior glottic stenosis. C. The temporary T-tube has been placed through a separate tracheotomy two rings inferior to the anastomosis. The superior limb ends superior to the true vocal folds, whereas the inferior limb is short. Other than closure of the laryngofissure, the remainder of the anastomosis is performed in the same manner as in previously described procedures.
Figure 63-1 demonstrates the common appearance of circumferential subglottic stenosis with involvement of the upper tracheal rings. Not only is the anterior subglottis narrowed, but also the posterior thickening impedes airway patency. Resection of such lesions is begun with induction of anesthesia by transoral intubation with a small-caliber endotracheal tube, often of an extended length to permit later entrance into the trachea without violating the balloon cuff. If the stenosis is of such caliber that dilation must take place before intubation, jet ventilation is used temporarily during the dilation, which is minimal, to avoid causing too much edema. A previously existing tracheotomy tube can be used for induction but is changed immediately to translaryngeal intubation such that the tracheostomy tube does not crowd the operative field. After intubation, the head is extended with a shoulder roll, and a transverse incision is made from sternocleidomastoid to sternocleidomastoid superior to the manubrium. The skin flaps are raised subplatysmally superiorly to the hyoid bone and inferiorly to the clavicles. The strap muscles are separated, and the thyroid gland is divided at the isthmus. Neither suprahyoid nor thyrohyoid release maneuvers are routinely used. The trachea is dissected in a pretracheal plane, very close to the cartilaginous rings to avoid damaging the recurrent laryngeal nerves, which we do not identify routinely. The trachea is dissected down to the carina to produce the mobility for future anastomosis, and care is taken to avoid dividing its lateral blood supply.
The cricothyroid muscle is elevated laterally to permit lateral division of the cricoid laminae. The proximal line of resection transects the cricothyroid membrane just inferior to thyroid cartilage and bevels laterally through the lateral laminae of the cricoid cartilage, usually more than halfway to a midlateral line. We then make a posterior cut at the inferior level of the cricoid cartilage, which may not resect the full extent of the posterior stenosis within the cricoid lamina. The stenosis within the cricoid then is resected off the posterior lamina once it is fully visualized with direct vision through the transected airway. A transverse cut against the posterior plate of the cricoid cartilage inferior to the vocal cords and arytenoid cartilages is made, leaving the denuded posterior plate of the cartilage intact. Removal of a portion of the posterior cartilaginous plate is sometimes necessary but risks injury to the recurrent laryngeal nerves. Preservation of at least the posterior perichondrium is required, and care must be used to avoid disrupting the cricothyroid joints superolaterally on the cricoid plate. It should be noted that depending on the patients age the cricoid may be significantly calcified and powered instrumentation may be necessary for precise resection.
The distal level of resection was determined earlier by endoscopic visualization. If the inferior border of the stenosis or tumor is in question, the initial transection always should be made slightly more superiorly because repeat resection more inferiorly is always possible. The first preserved ring is beveled backward from a high point in the anterior midline to the lower margin of that ring, creating an inverted U, and care is taken not to fracture this ring. At this point, a posterior membranous wall flap is formed to fit over the exposed posterior plate of the cricoid cartilage. The length of flap is determined by the amount of exposed posterior lamina. If needed, an additional anterior tracheal ring may be sacrificed to lengthen this posterior flap.
The shoulder roll then is removed and the field made orderly to prepare for closure. Endotracheal intubation is temporarily switched to cross-table ventilation to permit optimal access to the posterior wall closure. Four 3-0 Vicryl sutures are placed between the inferior margin of the posterior plate of cricoid cartilage to the base of the distal posterior tracheal flap. These sutures are clamped to the drapes such that they can be tied later in the order of the most anteromedial suture first, lateral suture second, and posteromedial suture last. Next, 4-0 Vicryl sutures approximate the tip of the posterior membranous wall flap of the trachea to the distal laryngeal mucosal line of resection within the cricoid cartilage. These sutures are placed from within the larynx, but the knots are arranged to lie outside the lumen and are clamped over the patient's head temporarily so as to avoid confusion with the external anastomotic sutures. Lastly, 3-0 Vicryl is used to complete the anastomotic closure, starting through the remnant of lateral cricoid cartilage to the second and third tracheal rings, followed by the thyroid cartilage to the first tracheal inverted U-ring. Tying of sutures begins after the patient is reintubated transorally and starts with the endolaryngeal 4-0 sutures, continues with the anteromedial sutures, and progresses laterally and posteriorly to the posterior midline. Strap muscles can be approximated over the anastomotic suture line, adding an additional layer of closure. Nonsuction drains are placed, the head is kept in a flexed position, and the patient is extubated immediately.
With tumors that occupy the laryngeal–tracheal junction, a resection similar to the type used to remove airway stenoses is employed. Benign tumors are removed with a minimal margin of normal tissue, whereas the rare malignancy confined to the endolaryngeal or endotracheal surface is removed with a margin dictated by the aggressiveness of the tumor. Preoperative imaging and initial endoscopy are used to determine the superior and inferior extents of the tumor, to rule out extralaryngeal and extratracheal extension, and to evaluate for distant metastasis.
The extent of the skin incision depends on the necessity of concurrent lymphadenectomy, which is performed before addressing the primary tumor. The larynx and trachea are exposed in an identical manner to the stenosis resection. Again, the superoanterior resection is made through the cricotracheal membrane to remove the anterior cricoid arch, curving laterally through the lateral cricoid laminae. An inferior incision then is made at the tracheal ring, which permits the tumor to be resected with a negative margin. At this point, a midline vertical incision is made to open the cricoid ring, and the upper tracheal rings are marked for resection. This allows optimal visualization before the posterior cuts are made. Although anterior tumors may be violated by this anterior midline incision, this does not preclude excellent tumor excision, albeit not adhering to the “no touch” tumor technique. In posteriorly placed tumors, the posterosuperior cut is made above the tumor site, with removal of underlying cricoid cartilage if the tumor requires. Again, the most common technique is drilling down the partial thickness of the posterior cricoid plate, although cricoarytenoid stability depends on preservation of the posterior perichondrium and a superior strut of cartilage on which the arytenoid articulates. The location of the inferior cut depends on two factors: it must be sufficiently inferior to allow for a negative tumor margin, and it should be made superiorly enough to form an inferiorly based posterior tracheal wall flap. If there is insufficient posterior tracheal wall to permit both these requirements, an additional anterior tracheal ring should be resected to generate more available posterior wall. A minimal posterior tracheal flap is needed for the repair of anterior tumor resections. The rest of the anastomosis and closure is identical to the stenosis repair detailed previously.
Superior Cricotracheal Tumor Resection
In patients with high subglottic tumor spread bordering on the undersurface of the true vocal fold or the interarytenoid area, the surgeon must be realistic in determining whether a laryngeal preservation operation is possible. Preoperative vocal fold fixation implies thyroarytenoid muscle involvement, cricoarytenoid joint fixation, or recurrent laryngeal nerve involvement, all contraindications to cricotracheal resection with laryngeal preservation. Nonetheless, cricoid tumors often will encroach either on the undersurface of the true vocal fold or the interarytenoid space, and surgical judgment must be used in determining the suitability of candidates for laryngeal preservation surgery. If the tumor is indeed judged to be favorable for resection, three modifications are made to the standard cricotracheal tumor resection technique. The first is a midline laryngofissure. This permits maximal tumor visualization, which is critical in such a location in which adequate margins are needed on the tumor, but postoperative laryngeal function depends on preservation of every millimeter of normal laryngeal structure. The second modification is the formation of a longer distal posterior tracheal wall flap to permit total resurfacing of the denuded posterior cricoid, even between the two arytenoid cartilages if required. This may necessitate resection of additional normal tracheal rings to generate sufficient length to reline the cricoid posterior wall. The last modification is placement of a temporary T-tube through the glottis for the initial 4- to 6-week postoperative period. The tube is placed with the proximal limb lying approximately 0.5 to 1.0 cm superior to the glottic level. The inferior limb can be quite short (2 cm). The horizontal limb is placed through a tracheotomy two rings inferior to the anastomotic line. Strap muscles are approximated to the area around the T-tube during closure to reinforce the airtight seal to prevent postoperative air leaks into the neck.