Учебники / Operative Techniques in Laryngology Rosen 2008

Fig. 44.7  External fixation of Montgomery stent

tion.

e) If the cricoid ring is unstable, then placement of an internal stent endoscopically or through an injury-induced laryngofissure can be performed. The best and preferred laryngeal stent options are listed above.

4. Internal laryngeal stent removal (Two-three weeks post-op- eratively)

a) General anesthesia is induced via the preexisting tracheotomy.

b) Direct laryngoscopy is performed to visualize the internal laryngeal stent.

c) A large cup forceps is used to grasp the stent and then the securing sutures of the stent can be released from the neck and the stent removed.

d)Microlaryngoscopy and telescopic examination of the larynx and upper trachea should then be performed to evaluate the structural integrity and mucosal integrity of the larynx.

e)Mitomycin C can be applied (as need; see Chap. 29, “Subglottic/Tracheal Stenosis: Laser/Endoscopic Management”). Endoscopic replacement of the stent can be done on an as-needed basis (see Chap. 26, “Anterior Glottic Web”).

44.6Postoperative Care and Complications

Postoperative care comprises:

■Tracheotomy care and education (as needed)

■Intravenous antibiotics for 24 hours

■Removal of drain within 24 hours

■Maintain internal laryngeal stent for approximately 14–30 days

■Microlaryngoscopy/bronchoscopy and stent removal (see above)

Complications can include:

■Laryngeal infection

■Stent migration (superior–inferior dimension)

■Stenotic laryngeal airway (anterior–posterior dimension and/or lateral dimension)

■Anterior commissure blunting/webbing

■Granuloma formation

Key Points

■All evaluation and treatment of laryngeal fractures should focus on:

■Airway lumen protection

■Voice quality and function

■Mucosal coverage is crucial for obtaining the best possible results after laryngeal fracture and injury.

■Internal laryngeal stenting should be performed if the lumen integrity of the laryngeal airway is compromised due to laryngeal fractures.

Selected Bibliography

1Thor A, Linder A (2007) Repair of a laryngeal fracture using miniplates. Int J Oral Maxillofac Surg 36:748–750

45.1Fundamental and Related Chapters

Please see Chaps. 6, 29, 46, and 47 for further information.

45.2Disease Characteristics and Differential Diagnosis

Subglottic stenosis is a narrowing of the subglottic airway, seen as both a congenital and an acquired lesion. The subglottis is the narrowest section of the airway, and it is contained entirely within a nonflexible cartilaginous ring. In contrast, the trachea has C-shaped cartilage anteriorly with an intervening posterior membranous section. Narrowing in this segment of the airway is termed tracheal stenosis.

Subglottic stenosis may be caused by a multitude of factors, depending on the age of occurrence and the presence of inciting factors. Congenital stenosis is caused by a failure of recanalization of the laryngeal lumen during embryogenesis. This type of stenosis is divided into membranous or cartilaginous types. The membranous type is marked by circumferential fibrous tissue, sometimes extending upwards to include the true vocal folds. The cartilaginous type is comprised of a sheet of cartilage extending posteriorly from the inner surface of the anterior cricoid ring, with a small posterior airway.

Acquired subglottic stenosis accounts for 95% of cases subglottic stenosis, of which 90% is intubation related. Subglottic stenosis after prolonged or repeated intubations occurs in 3–8% of children and adults. While intubation is the leading cause of stenosis, other potential internal and external disease processes may lead to the development of stenosis. A more comprehensive list of these etiologies is included in Chap. 6, “Glottic and Subglottic Stenosis: Evaluation and Surgical Planning.”

Although endoscopic methods are often employed in the treatment of subglottic and tracheal stenosis, there are clearly cases where these methods will fail. In these instances, external techniques such as laryngotracheal reconstruction with grafting (described in this chapter) or cricotracheal/tracheal resection with primary anastomosis (Chaps. 46, “Glottic and Subglottic Stenosis: Cricotracheal Resection with Primary Anastomosis” and 47, “Tracheal Stenosis: Tracheal Resection with Primary Anastomosis”) are commonly used.

45.3Surgical Indications and Contraindications

Indications include:

■Failed endoscopic treatment of laryngotracheal stenosis

■Cartilage collapse/tracheomalacia with obstruction

■Laryngotracheal stenosis> 2–3 cm in length

Contraindications (relative) comprise:

■Diabetes

■Steroid dependency (especially in autoimmune patients)

■Moderate–severe lung disease (COPD/restrictive disease)

■Moderate–severe heart disease

■Obstructive sleep apnea

■Renal failure

■Untreated autoimmune disease (e. g., Wegener’s granulomatosis)

■Untreated LPR

45.4Surgical Equipment

Equipment needed for surgery includes:

■Standard neck dissection tray

■Cottle and freer elevators

■Drill with cutting burr (optional)

■Nonabsorbable, monofilament suture with taper needle (such as Prolene or nylon)

■Malleable retractors

■Montgomery laryngeal stent of appropriate size (Boston Medical, Boston, Mass.)

■Sterile buttons and 0 or 2-0 permanent suture to secure stent

■Tracheotomy tube of appropriate size

45.5Surgical Procedure

1.The airway is obtained preferably by endotracheal intubation using a small-bore tube (4.0 ETT).

2.The neck and chest are prepped and draped.

3.A 5- to 6-cm horizontal incision is made over the seventh or eighth rib as indicated (Fig. 45.1).

a) Both of these ribs have adequate bulk for fashioning grafts. In addition, they are located in a region where the diaphragm is thicker, so there is less risk of pneumothorax. Dissection should be carried out until an appropri-

ately sized cartilage piece is exposed. In this region, the surgeon will encounter fibers from the rectus abdominus muscle, which must be dissected off the rib to expose the cartilage. Care should be taken to preserve the overlying perichondrium. The perichondrium is then incised along the superior, inferior, and lateral borders of the proposed graft.

4.Using a cottle or Freer elevator, the perichondrium is elevated along the periphery of the proposed graft (Fig. 45.2).

a)Elevation should continue around the undersurface of the rib, until the rib is freed circumferentially. It is crucial in this dissection to remain in the subperichondrial plane to avoid injury to the nerves and vessels running on the inferior surface of the rib and to avoid pneumothorax.

5.Malleable retractors are placed below the exposed rib to protect the underlying pleura.

a)Using a no. 10 blade, the rib graft is incised laterally and medially to free it from the rest of the rib (Fig. 45.3). The inner perichondrium should remain intact deep to

Fig. 45.3  Malleable retractors are placed below the exposed rib to protect the underlying pleura while sharp dissection is used to free the rib graft

Fig. 45.4  The inner perichondrium should remain intact deep to the rib, after graft removal

the rib, after graft removal (Fig. 45.4). The graft is then soaked in a saline solution.

6.The wound is closed in layers over a suction drain.

7.An incision is made in the skin of the neck horizontally overlying the cricoid and trachea.

a)If there is a previous tracheostomy, then one should incorporate the superior aspect of tracheostoma into the incision (Fig. 45.5). The incision should be wide enough to allow exposure of the lower portion of the thyroid cartilage and the first few tracheal rings.

8.Elevation of subplatysmal flaps is carried out, the midline raphae are divided, and the strap muscles are separated and retracted laterally to expose the laryngotracheal complex (Fig. 45.6).

9.Using a 15 blade, a midline cricoidotomy is performed and extended into the upper two to three tracheal rings (Fig. 45.7).

a)The extent of the incision is dependent on the length of stenosis. The cricothyroid membrane is divided horizontally to facilitate retraction of the cricoid segments laterally. Using this method, the entire length of stenosis is exposed, with extension of the incision above and below the stenotic site as well. The superior aspect of the incision may be extended into the inferior thyroid cartilage as depicted in Fig. 45.7. If not already present, a tracheostomy is then performed two or more rings below the inferior-most incision through the affected airway (Fig. 45.8). Ideally, the tracheostomy site is separate from the stented region, but this is not always possible. Having a tracheostomy site adjacent to the rib graft can lead to graft infection, granulation tissue formation, and restenosis.

10.The previously harvested costal cartilage graft is now prepared.

a)The cartilage is modified to the appropriate size and shape using a scalpel and/or drill with cutting bur. The ideal shape is either a modified boat shape or hexagon (Fig. 45.9). The beveled design prevents the graft from falling into the airway. Care should be taken to preserve the perichondrium; since this will serve as the internal lining of the reconstructed airway and a scaffold for epithelialization.

11.A Montgomery stent (appropriate for size/gender) is placed in the wound to help keep the lumen patent (Fig. 45.10).

12.The graft is inserted such that the perichondrium is oriented toward the lumen, and the graft is sutured into place.

a)Suture material is typically non-absorbable and monofilament (3-0 or 4-0 Vicryl). Sutures should be placed submucosally to reduce the incidence of granulation tissue formation. The sutures are not tied until the graft placement and position are confirmed (Fig. 45.11). The perichondrial surface of the graft should sit flush with the edges of the cricoidotomy.

13.The Montgomery stent is secured in place by passing two permanent sutures (0 or 2-0 Prolene) through the skin on one side, piercing the stent, and coming out on the skin of the opposite side.

a)These two suture ends are then tied over a button on the skin, taking care not to tie the ends too tightly, allowing for some postoperative edema (Fig. 45.12).

Fig. 45.11  Securing of the graft with multiple sutures extraluminally

45.6Postoperative Care and Complications

Postoperative care involves:

■Broad-spectrum antibiotics (first-generation cephalosporin, possibly clindamycin for coverage of anaerobes)

■A nasogastric tube is often placed during the initial postoperative period. This permits suctioning of the gastric contents to diminish the possibility of nausea and vomiting that put the surgical site at risk. It later serves as a vehicle for feeding.

■Acid-suppression medication (PPIs)

■Routine tracheostomy care

■Pain management

■Return to OR in 3–4 weeks for stent removal endoscopically

Complications can include:

■Voice alteration

■Pneumothorax or pneumomediastinum

■Loss of airway

■Graft failure

Voice alterations can occur if a laryngofissure is performed as a part of the surgery. Even small displacements of the anterior cartilage can disrupt voice quality. Pulmonary complications

Fig. 45.12  The stent is stabilized with percutaneous sutures tied over buttons

are also seen, including pneumothorax, pneumomediastinum, emphysema, and chest or neck wound infections. Infection is also of concern, particularly in its role in the development of a laryngocutaneous fistula. The most feared complication after any such surgery is loss of control of the airway. Emergent airway compromise may develop, in a patient with a tracheotomy by plugging or accidental decannulation. Finally, failure of the reconstruction with the need for a revision surgery is always a possibility of which patients and their families must be aware. The most common complication is failure to correct the stenosis. This is attributable to several aspects of the initial surgery, including inappropriate choice of graft or stent, inappropriate stent length, insufficient duration of stenting, inadequate endoscopic follow-up, slipped stent, persistent LPR or keloid formation.

Key Points

■Laryngotracheal reconstruction with costal cartilage rib graft is indicated in the following cases:

■Failed endoscopic treatment of laryngotracheal stenosis

■Cartilage collapse /tracheomalacia with airway obstruction

■Laryngotracheal stenosis > 2–3 cm in length

■Patients with significant co-morbid medical conditions are generally poor candidates for open laryngotracheal treatment of airway stenosis. This is due to a high failure rate and tendency toward restenosis, as well as higher morbidity/mortality.

■Costal cartilage is an ideal graft material for laryngotracheal reconstruction.

■The ideal shape for the costal cartilage graft is a modified boat shape or hexagon. The beveled design prevents the graft from falling into the airway. The preserved perichondrium on the graft serves as the internal lining of the reconstructed airway and a scaffold for epithelia­ lization.

■A Montgomery stent is used to maintain the airway lumen during the healing process, and is removed endoscopically 3–4 weeks later in the operating room.

Selected Bibliography

1Pena J, Cicero R, Marin J, Ramirez M, Cruz S, Navarro F (2001) Laryngotracheal reconstruction in subglottic stenosis: an ancient problem still present. Otolaryngol Head Neck Surg 125:397–400

2Cotton RT (2000) Management of subglottic stenosis. Otolaryngol Clin N Am 33:111–130

3Gray S, Miller R, Myer CM, Cotton RT (1987) Adjunctive measures for successful laryngotracheal reconstruction. Ann Otol Rhinol Laryngol 96:509–513

4Little FB, Koufman JA, Kohut RI, Marshall RB (1985) Effect of gastric acid on the pathogenesis of subglottic stenosis. Ann Otol Rhinol Laryngol 94:516–519

5Simoni P, Wiatrak BJ. Microbiology of stents in laryngotracheal reconstruction. Laryngoscope 114:364–367

6Zalzal GH, Cotton RT (1986) A new way of carving cartilage grafts to avoid prolapse into the tracheal lumen when used in subglottic reconstruction. Laryngoscope 96(Pt. 1):1039

46.1Fundamental and Related Chapters

Please see Chaps. 6, 29, 45, and 47 for further information.

46.2Diagnostic Characteristics for Open Treatment of Subglottic Stenosis

Numerous surgical procedures have been described to improve airway function in patients with benign acquired subglottic/tracheal stenosis, and the reported outcomes of these techniques vary, with no consensus on the optimal treatment. In patients with cricotracheal stenosis, a one-stage procedure that includes circumferential resection of the subglottis and tracheal region with primary thyrotracheal anastomosis has resulted in excellent outcomes.

As outlined in Chaps. 6, “Glottic and Subglottic Stenosis: Evaluation and Surgical Planning” and 29, “Subglottic/Tracheal Stenosis: Laser/Endoscopic Management,” endoscopic treatments are often used as a first-line treatment of glottic and subglottic stenosis. In cases where this approach fails, or conditions in which endoscopic treatment is not possible (e. g., cartilaginous collapse of the airway), open treatment with either laryngotracheal reconstruction (Chap. 45, “Glottic and Subglottic Stenosis: Laryngotracheal Reconstruction with Grafting”) or cricotracheal resection with primary anastomosis is indicated.

46.3Surgical Indications and Contraindications

The primary indication for the procedure is laryngotracheal stenosis contained within the cervical region, which fails endoscopic management.

Contraindications include:

■Stenosis at the glottic level (within 5 mm of free edge of the vocal folds)

■“Active” autoimmune or inflammatory process (e. g. Wegener’s granulomatosis)

■Stenosis that includes > 6.5 cm of the trachea

Relative contraindications can comprise associated comorbidities including severe vascular dysfunction, poor pulmonary

reserve, prior radiation to the larynx or trachea and patients taking immunosuppressive agents, i. e., high-dose steroids.

46.4Surgical Equipment

Equipment needed for this procedure includes:

■Standard head and neck surgery set

■Kerrison rongeurs

■Drill with 3-mm cutting burr

■T-tube (sizes 11–14, Hood)

■2 endotracheal tubes

■35 gauge wire, 4-0 Vicryl

46.5Surgical Procedure

1.The airway is generally secured with endotracheal intubation using a small-caliber endotracheal tube (ETT), such as a 4.0 microlaryngeal tube (MLT). If this is not possible, then an ETT can be placed though a tracheostomy during the resection portion of the case, and replaced by a oral endotracheal tube just prior to the re-anastomosis.

2.Under general anesthesia, the patient is placed in a supine position, and a shoulder roll is placed to extend the neck.

3.A standard, low-collar incision is utilized and the flaps are developed in the subplatysmal plane, exposing the airway from the hyoid bone superiorly to the manubrium inferiorly (Fig. 46.1). The strap muscles are then retracted and the thyroid isthmus divided in the midline.

4.The distal end of the stenosis is then identified, and the trachea is circumferentially mobilized to the inferior border of the cricoid cartilage (Fig. 46.2). Blunt dissection is used along the anterior wall of the trachea to the level of the aortic arch/carina, which then permits further mobilization of the trachea and a reduction of tension on the anastomosis. To maintain the vascular supply to the trachea, minimum lateral dissection is performed.

5.The cricothyroid muscle is then identified and reflected superiorly. The perichondrium on the upper and lower border of the cricoid cartilage is then incised, and the anterior segment is excised (Fig. 46.3). Dissection then continues on the inner aspect of the cricoid cartilage to protect the recurrent laryngeal nerves, which are located posteriorly and inferiorly. A Kerrison rongeur is used to excise further

Fig. 46.2  The distal end of the stenosis is identified and the trachea is circumferentially mobilized to the inferior border of the cricoid cartilage

Fig. 46.4  Further intraluminal removal of the stenotic region with a Kerrison rongeur, sparing the outer perichondrium and underlying recurrent laryngeal nerves