Adult Glottic Stenosis

Synonyms

Glottic web; Laryngeal stenosis; Laryngeal web; Posterior glottic stenosis

Definition

Chronic narrowing of the airway at the glottic level of the larynx; that is, at the level of the true vocal folds.

Classification

Stenosis at the level of the glottis can be divided into three categories: (1) anterior, (2) posterior, and (3) complete.

Anterior stenosis can be seen in two forms. The first is a simple anterior glottic web, which can be congenital or acquired (Fig. 1a). A web is a bridge of scar tissue between the true vocal folds that is covered with epithelium. It usually involves the anterior commissure. The second is a more complex form in which the true vocal folds, false vocal folds, and the ventricles are adherent to one another. This is usually the result of severe external laryngeal trauma and thyroid cartilage fracture.

Adult Glottic Stenosis, Fig. 1

(a) A small anterior glottic web. (b) A large anterior glottic web secondary to surgical trauma. Note the laryngeal papilloma visible on the right true vocal fold. (c) Interarytenoid scar band with a posterior sinus tract (Type 1 posterior glottic stenosis)

Posterior glottic stenosis (PGS) refers to narrowing of the airway at the posterior aspect of the glottic space. PGS has been further subclassified by Bogdasarian and Olson (1980):

• Type 1: Interarytenoid synechia or scar with a sinus tract posteriorly (Fig. 1c)

• Type 2: Interarytenoid scar without a sinus tract posteriorly, in which there is no fixation of either cricoarytenoid (CA) joint

• Type 3: Interarytenoid scar with fixation of one CA joint

• Type 4: Interarytenoid scar with fixation of both CA joints

Complete glottic stenosis typically results from inadequately managed external trauma. However, infection or trauma from prolonged intubation or endolaryngeal surgery may also cause complete stenosis.

Etiology

Endotracheal Intubation

Prolonged or traumatic endotracheal intubation is the most common cause of PGS. Intubation trauma can also result in anterior glottic webs and complete glottic stenosis (Rosen and Simpson 2008a); however, this is far less common.

The true incidence of PGS secondary to endotracheal intubation is unknown. In a prospective study of 200 patients, Whited noted an overall incidence of approximately 6% (Whited 1984). However, patients intubated greater than 10 days had a threefold increased risk of developing stenosis.

Endotracheal intubation results in pressure on the posterior glottis, causing mucosal ischemia, which eventually leads to ulceration, granulation tissue formation, and secondary infection (Benjamin 1993). The areas most affected are the medial aspects of the arytenoids, the CA joints and the interarytenoid space (Benjamin 1993; Weymuller 1988). Injury may also be the result of a traumatic intubation causing a mucosal tear. The healing process involves deposition of fibrous tissue, resulting in stenosis and CA joint fixation. Thus, patients typically develop symptoms in a delayed fashion, weeks to months after the intubation. Risk factors for the development of stenosis include the duration of intubation, size of the endotracheal tube, traumatic or repeated intubations, the presence of gastroesophageal reflux disease (GERD), acute or chronic conditions that lead to poor tissue perfusion or hypoxia (e.g., diabetes mellitus), and bacterial superinfection (Benjamin 1993; Gardner 2000).

Endolaryngeal Trauma

Surgery of the larynx, either via endoscopic or open approach, can result in trauma that leads to the formation of stenosis. Any procedure that creates a wound not covered with epithelium that crosses the anterior or posterior commissure is at risk of forming a web or stenosis. This is a common cause of anterior glottic webs.

Caustic ingestions and foreign bodies can also lead to inflammatory reactions that can result in glottic stenosis.

External Trauma

Trauma can result in fractures of the thyroid and/or cricoid cartilages, mucosal lacerations, and hematoma formation. The healing process, as discussed above for endotracheal intubation, can result in fibrous tissue deposition and stenosis.

Anterior or posterior glottic stenosis can occur if the relevant portions of the glottic mucosa or cartilaginous support are involved in the injury. Complete glottic stenosis is usually the result of severe external trauma to the laryngeal framework (Shapshay and Valdez 2003).

Radiation Therapy

External beam radiation therapy for aerodigestive tract malignancies induces an inflammatory response in the tissues within the radiation volume. This can range from mild reactions to severe inflammation resulting in chondronecrosis. As the tissues recover, there is a variable amount of fibrosis, which can lead to glottic stenosis (Benninger et al. 1998). These cases are particularly challenging to manage – surgical repair is complicated by poor wound healing.

Neoplasms

Neoplasms are a rare cause of glottic stenosis. Chondromas and chondrosarcomas of the larynx typically arise from the posterior cricoid lamina and may result in PGS. Respiratory papillomatosis, a benign neoplasm caused by the human papillomavirus, can also result in glottic stenosis. Common laryngeal malignancies such as squamous cell carcinoma can cause narrowing of the glottic airway due to impaired vocal fold mobility as well as mass effect from the tumor itself.

Inflammatory Conditions

Wegener’s granulomatosis (WG) is a vasculitis resulting in necrotizing granulomatous inflammation of the upper respiratory tract, lungs, and kidneys. The head and neck manifestations can present in the nasal cavity, middle ear, oral cavity, and larynx. The typical laryngeal manifestation is subglottic stenosis, with both acute or subacute stenosis from active inflammation and chronic stenosis from scar tissue formation. PGS, however, can also be seen. Although systemic disease is commonly seen, a form of WG that involves isolated airway manifestations has been described (Gardner 2000).

Relapsing polychondritis is an autoimmune inflammatory disorder that typically affects that cartilage of the ears, nose, and laryngotracheobronchial tree. The classic laryngeal manifestation is subglottic stenosis; however, PGS has also described.

Amyloidosis involves extracellular protein deposition in the larynx and can result in glottic stenosis. Other rare causes of stenosis include other inflammatory autoimmune diseases and sarcoidosis. The latter, however, typically affects the supraglottic structures. Anterior glottic webs can be caused by WG, sarcoidosis, and amyloidosis (Rosen and Simpson 2008a).

Infections

Infectious causes of chronic glottic stenosis are rare in the developed world. Tuberculosis classically causes granulomatous inflammation of the periarytenoid and interarytenoid region, posterior true vocal folds, and laryngeal surface of the epiglottis. Mucosal ulceration can lead to extensive perichondritis and chondritis. The resulting healing process can lead to extensive scarring and stenosis. Other rare infections such as Klebsiella rhinoscleromatosis, syphilis, leprosy, and diphtheria can also result in glottic stenosis.

Gastroesophageal Reflux Disease

GERD has been implicated in the pathogenesis of PGS as either the sole cause or as a contributing cause that prevents normal healing in the presence of injury caused by other mechanisms such as intubation or surgery (Hirshoren and Eliashar 2009).

Clinical Presentation

Patients with anterior glottic stenosis may have very minimal symptoms. Small anterior glottic webs (Fig. 1a) can cause mild dysphonia with an increase in vocal pitch and vocal effort. Webs can also be much larger (Fig. 1b), encompassing the entire length of the membranous vocal folds. These larger webs or more extensive stenoses can impair true vocal fold movement and thus can present with varying degrees of phonatory and respiratory symptoms.

PGS causes more significant airway-related symptoms due to limitation of true vocal fold abduction. Patients typically have dyspnea and stridor. This will vary from mild stridor and dyspnea only with exertion to respiratory distress and stridor at rest. Patients are often treated for asthma or other pulmonary conditions prior to presenting to an otolaryngologist for evaluation. The severity of the symptoms depends upon the degree of stenosis as well as the time frame over which the stenosis develops – patients may be relatively comfortable with a significantly narrowed airway that has developed over months to years. Voice complaints are less prominent in PGS; however, patients may have a rough and breathy quality to their voice, with complaints of vocal fatigue and decreased vocal projection. Swallowing problems, though less common, can occur if the stenosis prevents adequate adduction of the true vocal folds to protect the airway during swallowing.

Diagnostics

Physical Examination Including Flexible Laryngoscopy

A detailed and thorough physical examination is essential for the diagnosis and evaluation of patients with glottic stenosis. Stridor, signs of respiratory distress, and dysphonia should all be noted. The neck should be examined for signs of trauma, surgical scars, or masses.

Flexible fiber-optic laryngoscopic examination of the airway is the most crucial aspect of the patient’s evaluation. A thorough examination is facilitated by the application of topical laryngotracheal anesthesia, which allows for a detailed examination of the glottic, subglottic, and tracheal airway. Anesthesia can be administered via injection of topical lidocaine through the cricothyroid membrane or in a transtracheal fashion. This will induce a forceful cough that will effectively deliver the anesthetic to the laryngeal introitus. Alternatively, if a sideport is available on the flexible laryngoscope, the anesthetic can be dripped directly onto the true vocal folds.

Examination of the larynx should identify areas of stenosis and the amount of true vocal fold mobility with regard to abduction and adduction. Areas of significant scar tissue deposition that are contributing to the stenosis should be carefully examined. Furthermore, the scope can be passed distal to the vocal folds to assess for any coexistent pathology of the subglottis or trachea which may be contributing to the patient’s symptoms. Other sites of stenosis are common in patients with PGS, with reports ranging from 9.3% to 27.8% (Shapshay and Valdez 2003).

It can sometimes be difficult to distinguish between PGS and bilateral vocal fold paralysis. If this is the case, laryngeal electromyography (LEMG) and intraoperative examination may help elucidate the diagnosis (see below).

Imaging Evaluation

A high-resolution CT scan of the neck with 1 mm (or thinner) cuts through the larynx is helpful in further characterizing the location and extent of the stenosis. It is particularly helpful in evaluating for coexistent subglottic or tracheal stenosis. Both the degree and the length of such stenoses can be measured from the scan. The CT is also helpful in cases of external laryngeal trauma for determining the location and nature of cartilaginous framework disruption as well as in the diagnosis of neoplasms.

Laryngeal Electromyography

LEMG may be useful in distinguishing between PGS and bilateral vocal fold paralysis by testing for integrity of the recurrent laryngeal nerve function.

Evaluation of Swallowing

Many of the surgical treatments for PGS may worsen swallowing and aspiration. Any patients with swallowing difficulties or symptoms of aspiration at presentation should undergo a formal evaluation of their swallowing prior to any surgical intervention that may worsen swallowing function. A modified barium swallow (MBS) or flexible endoscopic evaluation of swallowing (FEES) are appropriate tools for conducting such an evaluation.

Pulmonary Function Tests

Although pulmonary function tests are not required to make the diagnosis of glottic stenosis, they can be helpful in monitoring success of treatment. Examination of flow volume loops and peak inspiratory flows provides objective measurement of airflow to complement patients’ subjective report of their symptoms.

Operative Evaluation

Rigid endoscopic examination under general anesthesia permits the surgeon to gather further essential information regarding the degree and nature of the stenosis. A rigid laryngoscope can be used to expose the glottis and can be suspended to allow for bimanual examination. The anterior and posterior glottis can then be carefully examined under magnified vision with either rigid telescopes or an operating microscope. Such telescopes or rigid bronchoscopes can also be used to evaluate the suglottis and trachea. The CA joints can be palpated to determine if they are mobile or fixed. Finally, areas of scar tissue can be palpated to determine consistency and suitability for surgical correction (Gardner et al. 1995). Biopsies for histopathology and/or microbiology can be done at this time if a neoplasm, infection, or inflammatory etiology is suspected.

Operative evaluation and intervention in patients with glottic stenosis requires careful airway management and excellent communication between the surgeon, anesthetist, and operating room team. If a preoperative tracheotomy is not present, the surgeon and anesthetist must decide upon the safest method for providing ventilation prior to beginning the procedure. Intubation may be possible, but even if this is the case, the endotracheal tube often obscures the laryngeal structures such that diagnostic evaluation is difficult of impossible. Jet ventilation can be delivered supraglottically when a rigid laryngoscope has exposed the larynx, via a rigid ventilating bronchocope, or through a Hunsaker Mon-Jet subglottic ventilation tube (Orloff 2002). If there is concern that the patient may obstruct when administered paralytic medications and that bag-mask ventilation or exposure of the airway may be difficult or impossible, exposure of the larynx can be obtained while the patient is spontaneously breathing prior to administration of paralytic medications. If the above methods are felt to be unsafe, a tracheotomy under local anesthesia should be performed (Gardner 2000).

Differential Diagnosis

• Bilateral vocal fold paralysis

• Bilateral arytenoid dislocation

• Cricoarytenoid joint ankylosis

• Paradoxical vocal fold motion disorder/laryngospasm

Prophylaxis

As the vast majority of cases of adult glottic stenosis are acquired, prevention is possible. The incidence of intubation-related stenosis can be dramatically reduced by decreasing the duration of intubation with early tracheotomy placement (Whited 1984). Furthermore, avoidance of traumatic or repeated intubations or inappropriately large tube size is essential. Medical management of GERD, bacterial infection, and chronic medical conditions such as diabetes is also important (Gardner 2000). Prompt and appropriate management of external trauma is also essential to prevention of the development of stenosis.

Care must also be taken during endolaryngeal surgery to avoid epithelial defects that cross the anterior or posterior commissure, which can result in web formation. This is especially true for surgery involving the anterior commissure. For example, when treating recurrent respiratory papillomas that cross the anterior commissure, papilloma should be left on one side at the commissure to avoid web formation. If this is not possible, mucosal flaps can be created to cover the epithelial defect on at least one side (Rosen and Simpson 2008a).

The role of GERD in the development of glottic stenosis is controversial; however, it likely contributes by preventing normal healing after injury (Gardner 2000). Appropriate medical management with proton pump inhibitor therapy is likely indicated in patients with an injury that predisposes to the development of stenosis and in patients who have undergone surgical management to relieve stenosis, irrespective of whether or not they have the classical signs or symptoms of GERD (Hirshoren and Eliashar 2009).

Therapy

Medical Therapy

Treatment of the underlying cause of the stenosis is important for inflammatory and infectious etiologies. Corticosteroids can reduce edema and improve airway patency acutely but do not provide a definitive solution unless an inflammatory or autoimmune process is the cause. If this is the case, other immunosuppressive medications may also be indicated. Consultation with a rheumatologist is essential in these cases. Infectious etiologies should be treated with appropriate antimicrobial agents and given the rarity of these infections, an infectious disease specialist should be involved in the care of these patients.

The use of botulinum toxin has been recently described as a potential treatment for patients with PGS (Ekbom et al. 2010). By weakening the thyroarytenoid and lateral cricoarytenoid muscles, the posterior cricoarytenoid muscle has less opposition and can lead to a more lateralized position of the vocal fold(s), resulting in an improved airway. Although this technique had good success in treating patients with bilateral vocal fold paralysis, results in patients with PGS were mixed. One patient with PGS and unilateral CA joint fixation experienced a significantly improved airway, while another patient with bilateral CA joint fixation did not experience any improvement (Ekbom et al. 2010).

Surgical Therapy

Anterior Glottic Stenosis

Not all cases of anterior glottic stenosis require surgical management. Only in rare situations does anterior glottic stenosis result in significant airway compromise. In these cases, surgery is indicated. More often, patients’ main complaint is dysphonia. The degree of dysphonia and each patient’s vocal demands and goals will dictate the need for surgical intervention.

Endoscopic Approach

Anterior glottic webs can be managed with suspension microlaryngoscopy and division of the web. This can be done with either the CO₂ laser or cold instruments. The web should be divided asymmetrically (Fig. 2a) such that the web itself can be used for mucosal coverage of one side of the anterior commissure (Rosen and Simpson 2008a; Shapshay and Valdez 2003). The resultant mucosal flap is then secured in place via placement of an endoscopic suture(s) (Fig. 2b).

Adult Glottic Stenosis, Fig. 2

(a) Asymmetric division of anterior glottic web (Reprinted with permission from Rosen and Simpson 2008a). (b) Mucosal flap created from asymmetric division of anterior glottic web sutured in place to provide epithelial cover to the anterior right true vocal fold

Larger anterior glottic webs, those with an inadequate mucosal flap, or those that fail the above approach may need endoscopic placement of a keel in addition to division of the web. Several techniques have been described for endoscopic placement of keels (Rosen 2008; Shapshay and Valdez 2003). Keels are typically left in place for 10–14 days and are then removed under general anesthesia.

Open Approach

An anterior laryngofissure approach is indicated when there is coexistent subglottic stenosis, severe supraglottic stenosis, or when multiple endoscopic procedures have failed (Shapshay and Valdez 2003). The areas of web or stenosis are divided and a laryngeal stent or keel is placed and secured over a button to the overlying thyroid cartilage lamina or the skin of the neck. A tracheotomy will be required for the duration of the stent placement, which can be removed endoscopically after 2–6 weeks (Montgomery and Cheney 1996; Shapshay and Valdez 2003).

Posterior Glottic Stenosis

As with anterior stenoses, not all patients with PGS require surgery. The primary indication for surgical intervention is significant airway compromise, which can range from severe respiratory distress requiring urgent surgery to limited exercise tolerance appropriate for elective intervention. A secondary indication is patient desire for decannulation from an existing tracheotomy placed for airway obstruction.

Any procedure directed to enlarge the glottic airway will sacrifice swallowing and voice outcome to some degree – patients must be made aware of this preoperatively. The guiding principle of these procedures is to conservatively enlarge the posterior glottic airway so as not to predispose to clinically problematic aspiration and to preserve the majority of the membranous true vocal fold, which is essential for voice production. A conservative approach is preferred to prevent these complications, knowing that the risk of restenosis will be slightly higher and that revision procedures may be required.

The surgical intervention with the least negative impact on voice and swallowing while providing an adequate airway is a tracheotomy. Patients must be made aware that a tracheotomy is an option, whether permanent or temporary to allow time for decision-making. Many patients, however, are resistant to the idea of having a permanent tracheotomy.

Endoscopic Approach

Lysis of Scar Band

Simple Type 1 PGS – an interarytenoid scar band (Fig. 1c) – can be lysed with cold instruments or a laser. Care must be taken to avoid injuring the interarytenoid mucosa, which could result in scarring and worsened PGS.

Arytenoidectomy (Total or Medial)

The classic CO₂ laser total arytenoidectomy was described by Ossoff et al. (1983) (Fig. 3). This involves vaporization of the arytenoid mucosa, the arytenoid cartilage, and a portion of the posterior true vocal fold, which results in a defect flush with the inner aspect of the cricoid cartilage. The large resultant defect does initially result in breathy dysphonia and aspiration of thin liquids. However, with time scar tissue does form, making the defect smaller and improving these symptoms while preserving enough airway enlargement for relief of the stenosis. The reported rate of decannulation was 86% (Ossoff et al. 1990). Numerous modifications of this procedure have been described in an attempt to reduce the significant negative impact on voice and swallowing and to provide more predictable healing, and thus, airway improvement results (Gardner 2000).

Adult Glottic Stenosis, Fig. 3

Comparison of total arytenoidectomy, medial arytenoidectomy, and transverse cordotomy (Reprinted with permission from Rosen and Simpson 2008b). 1 Transverse posterior cordotomy; 2 Medial arytenoidectomy; 3 Total arytenoidectomy

Crumley described medial arytenoidectomy (Crumley 1993), a procedure in which the medial body of the arytenoid and the overlying mucosa are removed using a laser to increase the size of the posterior glottic airway, while preserving the vocal process of the arytenoid and the membranous true vocal fold. This procedure achieves a 1–2 mm improvement in the airway size while preserving the phonatory glottis, thus minimizing the negative impact on phonation compared to total arytenoidectomy. Subsequent studies have confirmed the effectiveness of medial arytenoidectomy in terms of airway improvement, along with minimal negative impact on voice and swallowing (Bosley et al. 2005). Other authors have described preservation of the medial arytenoid mucosa, which can be endoscopically sutured laterally after the cartilage has been resected (Gardner 2000). This offers a more predictive healing response as opposed to leaving the underlying tissue exposed to heal secondarily.

Posterior (Transverse) Cordotomy

The posterior (transverse) cordotomy involves making a transverse incision, typically using a laser, through the true vocal fold, just anterior to the vocal process of the arytenoid (Kashima 1991) (Fig. 3). The lateral end of the incision should extend to the inner aspect of the cricoid cartilage. To achieve this, the incision often extends into the false vocal fold tissue. Classically, the vocal process is preserved and by avoiding cartilage exposure, the risk of postoperative granuloma formation can be reduced (Rosen and Simpson 2008b). However, if a larger airway is required, the vocal process can be removed and/or the procedure can be combined with a medial arytenoidectomy. The posterior cordotomy can be performed unilaterally or bilaterally, depending on the degree of airway improvement required. When compared to medial arytenoidectomy, posterior cordotomy seems to perform similarly with regard to airway improvement and impact on voice and swallowing (Bosley et al. 2005).

Microflap Technique

Both inferiorly (Dedo and Sooy 1984; Goldberg 2000) and laterally based (Rosen et al. 2008) microflap techniques have been described for managing type 2 or 3 PGS – that is, at least one CA joint should be mobile. In all of these techniques, a mucosal flap is elevated off of the interarytenoid scar tissue (Fig. 4). The underlying scar tissue is then removed or divided to mobilize the CA joint(s). The mucosal flap is redraped and endoscopically sutured in place to prevent new scar tissue formation. These procedures require the presence of a tracheotomy during the postoperative recovery to allow for adequate healing of the flap.

Adult Glottic Stenosis, Fig. 4

Microflap technique for repair of posterior glottic stenosis (Reprinted with permission from Rosen et al. 2008). (a) Incision for laterally based microflap. (b) Elevation of flap and division and/or excision of underlying interarytenoid scar tissue. (c) Redraping of microflap to provide epithelial cover of interarytenoid space

These techniques provide the advantage of airway improvement without compromising swallowing or the structure of the true vocal fold, thus maximizing voice outcome. Good results with these techniques have been reported in small groups of selected patients (Dedo and Sooy 1984; Goldberg 2000).

Open Approach

The indications for open repair of PGS include failed endoscopic procedures, laryngeal trauma with significant disruption of the cartilaginous framework, and inability to adequately expose the glottis endoscopically. For all open procedures, patients should have a tracheotomy during the postoperative period.

Anterior Laryngofissure

The classic approach to the posterior glottis is via an anterior laryngofissure, which provides excellent exposure. Care must be taken to divide the thyroid cartilage precisely in the midline to avoid injury to the membranous vocal folds. Montgomery described elevation of a mucosal flap in the posterior commissure, allowing excision of the posterior glottic scar tissue and the typically fibrosed interarytenoid muscle (Montgomery 1973). This allows for mobilization of the CA joints. The mucosal flap is then redraped and sutured in place. Other authors have described using free grafts instead of creating a pedicled mucosal flap – mucosal, skin, and perichondrocutaneous grafts have all been described (Gardner 2000; Hoasjoe et al. 1997).

Typically, a conforming laryngeal stent is placed and secured to the overlying thyroid lamina or neck skin between 1 and 6 weeks depending on the severity of the stenosis and the extent of the repair. It can then be removed endoscopically under general anesthetic, at which time any granulation tissue can be excised or vaporized with a laser.

Arytenoidectomy (see below) can also be combined with this procedure to provide further enlargement of the posterior glottis. If the cartilaginous framework of the larynx has been significantly disrupted, more complex reconstruction may be required (Shapshay and Valdez 2003).

Arytenoidectomy

A total or subtotal arytenoidectomy can be completed via open approaches. The most direct approach is an anterior laryngofissure. The arytenoid can also be approached laterally via an approach similar to that used for arytenoid repositioning surgery. The posterior border of the thyroid cartilage lamina is exposed and the pyriform sinus mucosa is carefully dissected away from the cricoid cartilage and posterior cricoarytenoid muscle, exposing the muscular process of the arytenoid cartilage.

Complete Glottic Stenosis

Management of complete glottic stenosis can be complex and is directed by the underlying etiology. Traumatic injuries may require open reduction and fixation of any laryngeal fractures. An anterior laryngofissure is usually required to allow excision of the stenosis, mucosal or skin grafting, and placement of a conforming laryngeal stent (Shapshay and Valdez 2003).

Adjuvant Treatment

Antibiotics

The use of antibiotics in the perioperative setting is generally recommended to prevent perichondritis and chondritis, which can lead to new scar formation and restenosis. However, the evidence for their benefit is mixed in both animal and human studies (Hirshoren and Eliashar 2009).

Intralesional Corticosteroids

Corticosteroids delay the synthesis of collagen in the early stages of scar formation and increase the lysis of collagen in the later stages. Thus, intralesional corticosteroid application may have some benefit in preventing restenosis after surgery. However, as with antibiotics, the evidence supporting their use from animal and human studies is conflicting (Hirshoren and Eliashar 2009).

Mitomycin C

Mitomycin C is an alkylating agent that leads to cross-linking of DNA and is used as an antineoplastic drug for the treatment of several solid tumors. It has also been shown to inhibit fibroblast proliferation and the wound-healing response when applied topically (Hirshoren and Eliashar 2009). Several studies have shown a significant reduction in the incidence of restenosis with the topical application of mitomycin C during the surgical treatment of laryngotracheal stenosis in both animal and human studies (Hirshoren and Eliashar 2009; Perepelitsyn and Shapshay 2004). It is typically used at a dose of 0.4 mg/mL. However, there is controversy as to the subgroups of patients who are most likely to benefit and the potential side effects. Some animal studies have suggested that mitomycin C is beneficial only for fresh scar tissue and not for more mature stenosis (Hirshoren and Eliashar 2009). Studies in humans have found that fibrinous debris can accumulate at the application site, leading to airway obstruction. However, this complication was most often seen with higher does (≥10 mg/mL) (Hirshoren and Eliashar 2009).

Cross-References

Difficult Airway

Hoarseness and Pediatric Voice Disorders

Subglottic and Tracheal Stenosis in Adults

Vocal Cord Surgery