Acquired Glottic Stenosis—The Ongoing Challenge: A Review of Etiology, Pathogenesis, and Surgical Management 1Yonatan Lahav, 1Hagit Shoffel-Havakuk, and Doron Halperin, Rehovot, Israel Summary: Objective. To review the etiology and pathogenesis of acquired glottic stenosis, as well as the workup, patient preparation, interventional options, and their changing trends, as described in the literature since the 19th century until the present day. Methods. Literature from the PubMed search engine and the authors’ personal experience were used. The search included up to date studies and historical reports covering different aspects of glottic stenosis, such as basic science, pathogenesis, anesthesia, and surgical techniques. Results. At present, the most common etiology for acquired glottic stenosis is damage to the posterior commissure after intubation. Until less than a century ago, infectious diseases such as diphtheria and syphilis were the most prevalent etiologies. The common pathway of stenosis includes mucosal and cartilaginous ulcers, granulation formation, fibrosis, and tethering scars. Planning of surgical intervention must begin with the matching of expectations with the patient and considering voice versus airway functions. Preoperative tracheotomy should be considered for securing the airway. Anesthesia has to be carefully planned, and both the surgeon and the anesthesiologist have to be familiar with the options for tubeless jet ventilation. Surgical options include a variety of open and endoscopic resection and reconstruction procedures, which are reviewed in this article, followed by images and illustrations based on the authors’ experience. Conclusion. Acquired glottic stenosis compromises the breathing, voice production, and airway protection. Reconstructing the stenosed glottis is one of the major challenges facing laryngologists in this era. For this reason, the surgeon must be familiar with the variety of treatment options. Key Words: Glottis stenosis–Stridor–Dyspnea–Laryngeal reconstruction. INTRODUCTION ‘‘The management of chronic (laryngeal) stenosis, so varying in its nature and indications for treatment, will always require patience, perseverance and ingenuity (Lefferts, 1890).’’
The larynx serves multiple vital functions and shares similar units in all mammals, including airway protection during swallowing, breathing coordination, and intrathoracic pressure regulation. Voice production is the latest evolutionary modification.1 The unique functions of the larynx require delicate timing while performing acts and counteracts in extremely short intervals. Glottic stenosis significantly impairs the whole spectrum of these functions. METHODS In this review, we used the PubMed search engine and the authors’ personal experience. The search included up to date studies and historical reports covering different aspects of glottic stenosis, such as basic science, pathogenesis, anesthesia, and surgical techniques. The search used the following keywords: larynx, glottis, airway, and stenosis. Articles discussing Accepted for publication October 22, 2014. From the Department of Otolaryngology - Head and Neck Surgery, Kaplan Medical Center, Rehovot, Israel. 1 Hagit Shoffel-Havakuk and Yonatan Lahav contributed equally to this work. Address correspondence and reprint requests to Yonatan Lahav, Department of Otolaryngology - Head and Neck Surgery, Kaplan Medical Center, P.O.B 1, Rehovot, Israel. E-mail: [email protected] Journal of Voice, Vol. -, No. -, pp. 1-10 0892-1997/$36.00 Ó 2014 The Voice Foundation http://dx.doi.org/10.1016/j.jvoice.2014.10.012
congenital and pediatric stenosis or stenosis extending beyond the glottis were excluded. ETIOLOGY In 1858, Bouchut2 reported croup as a cause of laryngeal stenosis. O’Dwyer and Lefferts in 1890 described diphtheria and syphilis as an etiology. Solis-Cohen contributed a report of stenosis caused by tuberculosis in 1888. Diphtheria was a major concern because of sloughing of the mucosa required repeated interventions and stenosis was the end stage. Less common infectious causes included leprosy, rhinoscleroma, smallpox, measles, pertussis, and blastomycosis.3 In the later 1900’s, trauma became a more prevalent cause, either external or as a result of endotracheal intubation and tracheotomy. Lack (1909) and Jackson (1921) related cricoid damage to urgent tracheotomy performed too high in the trachea. Since the late 1940’s, endotracheal intubation became the most significant etiologic factor, along with other types of trauma such as motor vehicle accidents, laryngeal surgery, or radiotherapy. Table 1 summarized historic and current etiologies for glottic stenosis. HISTOPATHOLOGY AND PATHOGENESIS Whatever the cause, the events leading to glottic stenosis consist of ulceration of mucosa and cartilage, inflammation with granulation, and fibrous contraction.4 Ulceration may occur at varying depth, and granulation will form if the basement membrane is absent. If the epithelium fails to cover the granulation tissue, the latter may continue growing and progress to fibrosis. Annular granulations cause fibrotic scar formation, which contract and tether the vocal folds. Total or partial fixation of the cricoarytenoid joint may follow.
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TABLE 1. Etiologies of Glottic Stenosis Etiology
Examples
Pathogenesis
Traumatic – external Traumatic – internal Traumatic – iatrogenic
Blunt or penetrating Chemical/thermal burn After intubation
Infectious Inflammatory
After laryngeal surgery After irradiation Syphilis, diphtheria Wegener’s
Cartilaginous fractures and mucosal tears Supraglottic and posterior glottic scars Pressure necrosis over interarytenoid mucosa, arytenoids, and cricoid Circular surgical scar Edema, necrosis, fusion of subunits Scar maturation after granuloma formation Granuloma and scarring
SPECIFIC VULNERABLE LARYNGEAL SITES Glottic stenosis is referred to as anterior, posterior, or complete.5,6 The anterior glottis is prone to stenosis if the mucosa on both sides of the anterior commissure is denuded, with scarring causing fusion of the folds. The severity depends on the portion of the membranous vocal fold involved (Figure 1). The posterior glottis is the most vulnerable area to postintubation stenosis because of the pressure placed on the cartilages and the thin mucosa by the endotracheal tube (Figure 2). Convexity of the tube acts as a fulcrum against the posterior glottis. Tracheal angulation increases the pressure of the tube against the nonresistant respiratory epithelium.7 Fourteen percent of patients
FIGURE 1. The normal anterior glottis in a three-dimensional scheme, viewed from posterior to anterior. Note the relations between the vocal folds (VO) and vestibular folds (VE) joining at the anterior commissure. A continuous ‘‘V-shaped’’ mucosal damage in this region (arrow) is the key to late stenotic scar formation; the vocal folds will become fused by the contracting scar during the healing process of such a wound.
intubated for more than 10 days are susceptible to stenosis. Other risk factors include multiple extubations–reintubations, largesized tubes, tube motion, and infection.7 Also, patient-related factors such as diabetes mellitus, congestive heart failure, and a history of stroke or tuberculosis were found to increase the risk of severe laryngeal injury.8 Posterior glottic stenosis was classified into four stages by Bogdasarian and Olson9: type I: adhesion between vocal processes; type II: interarytenoid scar with preserved antero-posterior arytenoids mobility; type III: scar extending to one arytenoid; and type IV: bilateral cricoarytenoid ankylosis. Total glottic stenosis refers to complex conditions involving both the anterior and posterior glottis.
FIGURE 2. The normal posterior glottis in a three-dimensional scheme, viewed from anterior to posterior. Note the vulnerable sites: arytenoids (A), vocal processes (VP), interarytenoid muscle covered by interarytenoid mucosa (IA), and posterior cricoid rim (C). Any mucosal injury involving the interarytenoid compartment along with one or two arytenoids and vocal processes may lead to significant airway compromise due to stenotic scar formation.
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EVALUATION AND WORKUP Workup for glottic stenosis is summarized in Table 2.10,11 The most important aspect of preoperative evaluation would be an awake examination of the patient in the office. The pharyngeal, laryngeal, and tracheal airway should be carefully assessed endoscopically with optimal topical anesthesia. Residual spontaneous mobility of the arytenoids should be assessed and video documented for further follow-up and comparison with postoperative results. Obstruction at other sites other than the glottis must be ruled out before any surgical intervention. INDICATIONS FOR INTERVENTION When a patient presents with respiratory distress and a compromised airway, intervention is mandatory. The form of intervention might be bypassing the stenosed glottis, as in the case of tracheotomy, or reconstruction of the glottis. The treatment strategy should be tailored to the type and degree of stenosis, the etiology and the patient’s needs, and medical history. There is no absolute contraindication for intervention. If possible, treatment should be delayed until the patient is in the best condition, and the causative factors have been controlled and cured. This is the case for infection, granulomatous disease, papilloma, and carcinoma. If uncontrolled, such diseases might be reactivated or grafted to previously unaffected regions.3 TREATMENT STRATEGIES, CONSIDERATIONS, AND CONFLICTS Treating the stenosed glottis should be aimed at restoring cricoarytenoid joints mobility, valve mechanisms, breathing, swallowing, and voicing. Conservative treatment Obese patients can benefit from weight loss. The airway will expand due to parapharyngeal and paraglottic fat loss. Oxygen
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supplementation may delay respiratory exhaustion. Inflammatory diseases, such as Wegener’s granulomatosis, may respond to anti-inflammatory medications. Bypass Tracheotomy should be considered for temporary or permanent airway relief. A tracheostomy is also advised as a safe airway during a period of consecutive surgical procedures. Endoscopic surgery versus open surgery The endoscopic approach results in less morbidity and allows faster recovery. It is limited in tissue removal and grafting and often requires multiple interventions. Some surgeons believe endoscopic measures should be exhausted first before offering the patient an open procedure. Others suggest that an open procedure is better done as a first resort and not last.3 Stenting Stenting may prevent restenosis and allow for complete epithelial growth. However, the stent itself may cause irritation, leading to the recurrence of stenosis once the stent is removed. Powered instruments These are used for precise tissue removal with better hemorrhage control. CO2 laser12,13 is suitable for scar tissue removal, arytenoidectomy, cordectomy, and flap elevation. Its disadvantages include collateral heat distribution, delayed healing, and granulation formation. Microdebrider can remove excessive granulation and scar tissue14 although they may recur.15 Coblation uses radiofrequency coupled with constant saline irrigation to create an ionized environment which ablates tissue with minimal thermal necrotic damage.16 The authors have treated complex postirradiation glottic and subglottic stenosis using this technique with relative success in maintaining an open airway, sufficient enough for voice production. Further experience and follow-up is required.
TABLE 2. Evaluation and Workup10,11 History Examination
Imaging Polysomnography Laryngeal EMG Pulmonary function tests Blood work
Intubation, neck trauma, laryngeal surgery, irradiation Dyspnea at rest and effort, voice quality, sleep disturbances Dysphonia and stridor, use of accessory respiratory muscles Obesity, surgical scars, tracheotomy site, neck masses Rigid and flexible endoscopic examination of larynx Examination of trachea via the larynx or tracheotomy Multiplanar CT or MRI of the neck The extent of stenosis, proximity of scar tissue to muscle, and cartilage Glottic stenosis can be associated with obstructive sleep apnea Important in perioperative management To differentiate between glottic stenosis and vocal fold paralysis Spirometry and flow curve measures (typically demonstrate variable extrathoracic obstruction) to compare preoperative and postoperative functions Markers of inflammation and autoimmunity
Abbreviations: CT, computed tomography; EMG, electromyography; MRI, magnetic resonance imaging.
4 DEVISING A TREATMENT PLAN WITH THE PATIENT Glottic stenosis may require multiple interventions with a variable degree of relief. The patient must be informed that the different physiological aspects of the normal larynx may not function as efficiently in the reconstructed larynx. He or she must prioritize which of the functions is more important to them. A person that favors his voice may agree to keep a patent tracheotomy and avoid destructive procedure at the glottis, whereas a patient who wishes to avoid a tracheotomy may agree to sacrifice the quality of the voice. ANESTHESIA Airway securing and ventilation can be obtained by transoral intubation, tracheotomy, or jet ventilation. Open surgery will almost always require a tracheotomy. Endoscopic surgery can be performed with an endotracheal tube. The surgeon may have to change the position of the laryngoscope, anterior and posterior to the endotracheal tube, to allow adequate exposure. Tubeless jet ventilation allows for extended endoscopic surgical field without the inconvenience of a tracheotomy.17–19 The air jet is delivered via a narrow cannula, positioned in one of three locations: (1) supraglottic, in conjugation with the operating laryngoscope (Figure 3); (2) subglottic, via translaryngeal cannula or a transcutaneal cannula; and (3) Transtracheal percutaneal cannula. The last may be dangerous in a relatively obstructed larynx as high pressure may develop. The supraglottic approach is the safest and most commonly used.
FIGURE 3. Supraglottic jet ventilation: The jet parameters (frequency, volume, O2%) are set by the generator (asterisk). The jet is delivered by a tube (arrowhead) connected to the suction cannula (thick arrow) of the surgical laryngoscope (thin arrow), which is positioned above the glottis.
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SURGICAL TECHNIQUES Bouchut in 1858 and Schrotter in 1870 used laryngostomy tubes to bypass laryngeal stenosis. O’Dwyer in 1885 and later Rogers in 1905 used a preshaped endolaryngeal tube and placed it in the larynx via the mouth, using force when necessary.2,3 Laryngeal dilators were passed through the mouth for anterior glottic web opening, often painful and unsuccessful.5 In the first major conference on laryngeal stenosis in London in 1909, an open surgical approach was advocated by Lack and Delsaux and gained popularity. Arbuckle introduced a molded plug made of rubber, placed in the new laryngeal lumen, and covered by a skin graft. During the 1930s–1940s, the common practice was laryngofissure, scar removal, skin grafting, and stenting. In 1950, McNaught concluded that epithelization is essential to prevent reformation and introduced the tantalum keel for anterior stenosis repair. Since the 1930’s, endoscopic procedures have also been reported. These included incision of scarred tissue and endoscopic placement of stents. Bouginage was very effective in treating a thin diaphragmatic scar. Jackson and Coats reported intralaryngeal resection and repeated adhesiolysis. This was later abandoned due to multiple recurrences and scarring. Toward the end of the 20th century, the principles of open procedures were still valid, as stated by McIlwain, ‘‘the open approach has stood the test of time.’’ However, over the years, with the increasing experience of the surgeons, improved microsurgical tools and laser technology, a variety of conservative endoscopic procedures have emerged. SURGICAL TECHNIQUES FOR ANTERIOR GLOTTIC STENOSIS Keels and stents Cutting in two stages—one side done in the first procedure and the other side in the next. This strategy may be successful with thin anterior webs. A single stage cutting procedure requires a keel or a flap to prevent reformation. The original tantalum keel described in 1950 was replaced by umbrella-like silicon rubber stents. The procedure starts with endoscopic separation of the web, followed by open midline thyrotomy. The web is incised and a keel is inserted. The external part of the keel is firmly attached to the thyroid cartilage to prevent asynchronous motion and further granulation formation, and the laminas are well fixed to each other to avoid emphysema (Figure 4). Complete epithelization of the incised vocal folds is expected within 9–12 days after surgery. Granulations may develop if the keel is kept longer, as observed in the experimental canine model. The keel should be removed 2–3 weeks after surgery. This can be done in the office under local anesthesia.5 A keel can be introduced and secured endoscopically, sutured to the skin by the Lichtenberger endo-extralaryngeal needle carrier.20 Alternatively, Rice21 suggested securing a stent to the nasal septum rather than to the cartilage or skin to allow safe office removal. Grafts and flaps A free tissue graft can be used as a substitute for an artificial keel.22 The web is separated in a combined endoscopic-open approach. Mucosal graft is harvested from the buccal mucosa
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FIGURE 4. (A) A 72-year-old male with severe anterior glottic stenosis after bilateral cordectomy for squamous cell carcinoma. Note the granulation tissue at the stenotic segment at the anterior commissure (arrows). (B) The web was separated via laryngofissure approach. A silastic keel was positioned between the separated folds and secured to the thyroid cartilage. (C) 1 year after keel removal. Note the reconstructed anterior commissure. The vocal folds are mobile and the airway is safe. and sutured to the anterior commissure region bilaterally, until complete closure is achieved. Another variation is the cartilageperichondrium butterfly graft23 harvested from the thyroid cartilage. Perichondrium is sutured bilaterally, whereas cartilage is secured between the ala. An epiglottic flap can be used in selected cases of a large anterior commissural defect. The epiglottis is released and moved toward the glottis.24 Endoscopic suturing techniques aim to avoid grafting and stenting after lysis.25–27 This is suitable for webs involving up to the entire length of the membranous vocal fold. Webs are incised in the midline and trimmed to allow good adhesion of the mucosa. The free edge of each fold is sutured to achieve mucosal continuity. The authors favor the following technique: the superior epithelium of the web is removed and raw surface is exposed. This is later cut on one side along the free margin of the fold and sutured to the other side. Complete separation is achieved by unilateral suturing (Figures 5 and 6).
Two techniques were reported—membranous and cartilaginous. In the first,30 the posterior glottis is approached using a laryngofissure, and a mucosal flap on the more affected side is elevated. Scar tissue and muscle are resected between the mucosa and cartilage. In the second technique, the same approach is used for submucosal arytenoidectomy.31
SURGICAL TECHNIQUES FOR POSTERIOR GLOTTIC STENOSIS Open resection with grafting and stenting The larynx is entered through a laryngofissure. The scarred mucosa and the interarytenoid muscle are resected. The degree of tissue removal and reconstruction is determined by the type of stenosis. For type I, lysis of the scar tissue may be sufficient. For type II, scar tissue and interarytenoid muscle resection may be necessary, covered by a postcricoid advancement mucosal flap.28 Alternatively, a skin or mucosal graft can be used. For type III, an aryepiglottic flap may be used to cover the defect. In type IV, arytenoidectomy may also be needed. In all cases, an intralaryngeal stent is kept in place for a variable amount of time, ranging from 5 days to 8 weeks.6,7,9,29
Endoscopic lysis Dilatation is the simplest technique but generally not recommended because of a high recurrence rate.9 Midline lysis by cold-steel instruments or laser may be sufficient for type I stenosis9,34(Figure 7). Bilateral transverse cordotomy, anterior to the vocal processes, was described for type IV stenosis. Transverse cutting in a coronal plane at the posterior border of the vocal folds creates triangular widening on each side because of the muscular tension toward the anterior commissure. This allows a wider posterior glottic airway passage.35
Submucosal resection by open laryngofissure approach Submucosal resection is advised to expand the glottic airway while keeping the mucosa intact and avoiding a graft or flap.
Minimal open approach resection Inspection of the posterior glottis with minimal intervention through an open anterior approach may be accomplished by a limited exploration without laryngofissure. A cricothyrotomy approach was offered for lysis of type I interarytenoid band.32 Anterior window laryngoplasty, demonstrated on cadavers,33 has also been suggested for the same purposes, using a mini trapdoor at the midline of the thyroid cartilage. In selected cases, this may avoid possible complications of laryngofissure and the need for tracheotomy.
Endoscopic cordectomy Unilateral cordectomy, performed by laser (as in oncologic resection), can significantly improve the stenotic airway. This can be done either in a submucosal, subligamental, or transmuscular plane. As long as the free edge remains straight and smooth after healing and the contralateral side is kept intact, voice quality is relatively preserved.10,13 Revisions may be required as restenosis often occurs to some degree (Figure 8).
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FIGURE 5. (A) Schematic diagram through an anterior glottic web in coronal plane viewed from posterior to anterior. (B) Dissection and resection of the superior scarred layer of the web. Note the intentional asymmetry in tissue removal more on the upper left side, to allow for optimal positioning of the flap (C) Cut along the inferior right margin of the web. (D) Endoscopic suturing of the right free margin of the flap to the left vocal fold’s edge.
Endoscopic arytenoidectomy Arytenoidectomy may improve the airway while potentially keeping the membranous vocal fold intact. Total arytenoidectomy is not recommended because of significant aspiration and dysphonia. Partial laser arytenoidectomy is more acceptable, from vocal process to medial arytenoidectomy, while preserving the outer rim of the arytenoid36,37 (Figure 9).
Endoscopic scar resection with lateralization After endoscopic scar tissue removal, unilateral lateralization with the Lichtenberger needle carrier38,39 can secure the airway while avoiding stenting or tracheotomy. The vocal fold is sutured to the strap muscles or skin until healing of the posterior commissure takes place. Sutures are removed once arytenoid motion is detected.39,40 In case of an immobile
FIGURE 6. (A) A 56-year-old female with severe anterior glottic stenosis after bilateral vocal fold stripping for Reinke’s space edema. Surgery included removal of upper surface of the web, cut along the right margin, folding and suturing to the left. (B) A month after surgery, note the two sutures (PDS 6/0) along the free edge of the left vocal fold (arrows). (C) Six months after surgery, persistent complete separation of the vocal folds due to the tight epithelial closure on the left side during the surgery.
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FIGURE 7. (A) A 64-year-old female who developed stridor and dyspnea 2 weeks after thoracoscopy with endotracheal intubation for partial esophagectomy. Note the interarytenoid granulation tissue bridge (type I stenosis). (B) The lesion was cut in the middle under topical anesthesia with forceps advanced via the working channel of a transnasal videoendoscope. (C) Three months after the intervention, the arytenoids are free and mobile, with no evidence of residual granulation or stenosing scar.
fixed arytenoid, the cricoarytenoid joint is released and lateralized by a suture in the same technique.41 Endoscopic resection with flap reconstruction Release of the fixed cricoarytenoid joints by resection of the posterior commissure scar tissue, with or without removal of interarytenoid muscle, followed by an advancement of a posterior-cricoid-based mucosal flap toward the exposed region. The flap is sutured to the arytenoid and cricoid mucosal edge. No stent is required (Figure 10). The flap can also be advanced from the aryepiglottic and vestibular folds and rotated to the posterior commissure.42 USE OF MEDICATIONS Several types of medications are used to modulate the different wound healing phases and minimize restenosis after surgery. The three phases of healing consist of inflammation, proliferation, and maturation. Steroids and Mitomycin C are the medications most commonly used. Systemic or locally injected
steroids43 affect the first and the second phases. Mitomycin C applied topically affects the proliferative phase and was suggested in several reports as an effective adjuvant treatment.44 Antireflux medication and antibiotics are advocated by many authors.45 Current data support using steroids, antibiotics, and antireflux medications while the efficacy of Mitomycin C is considered unproven.46
POSTOPERATIVE CARE If the patient does not have a tracheotomy tube, then overnight intensive care unit observation should be considered. The timing of tracheostomy removal depends on the indication for its use. If the patient was tracheotomy dependent before surgery, then often, it should be kept in place for months after surgery. There are no absolute guidelines for timing of stent removal. Influencing factors include the degree of stenosis, type of stent, and the surgeon’s preferences. If the stent is removed before complete epithelization occurs, then restenosis is likely to happen. If the stent is kept too long, then new granulations, necrosis, and
FIGURE 8. (A) A 28-year-old male who developed posterior glottic stenosis 3 months after intermittent traumatic intubation for transient hepatic encephalopathy. The cricoarytenoid joints were fractured and fixed, and the patient was tracheotomy dependent. A series of three endoscopic partial cordectomy on the right side with preservation of the left vocal fold enabled weaning of tracheotomy with sufficient glottic airway (B, inhalation) and good vocal function (C, phonation).
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FIGURE 9. (A) A 68-year-old male with posterior glottic stenosis after multitrauma in motor vehicle accident and prolonged intubation. (B) A left partial arytenoidectomy and cordectomy were performed, and the raw surface was covered by posterior cricoid mucosa (asterisks). Note the improved glottic airway. The patient was weaned off the tracheotomy tube. scarring may develop. Reported stenting duration varies from 5 days to 8 weeks.6,7,9,29,30 A study performed on a canine model showed that the best results are achieved with removal of the stent after 14 days.5 Patients should be followed for years after the procedure because stenosis may recur at any time, especially in patients with chronic inflammatory conditions. FUTURE DIRECTIONS Imaging Higher resolution imaging that discriminates muscles, mucosa, cartilage, and joint capsule from fibrosis may lead to the site of malfunction and better selection of treatment.
Tissue expansion techniques Special devices for cartilage/bone distraction or elongation, inflatable stents, and devices capable of expanding the narrowed lumen may have a role in treatment. Tissue engineering Stem cells replacing scarred tissue with normal elastic mucosa may restore normal function. Advanced endoscopic techniques Three-dimensional vision, delicate surgical tools, and robotic control may allow for complex tasks considered impossible
FIGURE 10. (A) A patient with posterior glottic stenosis due to prolonged intubation after head trauma. (B) The interarytenoid mucosa and muscle were resected, arytenoids were separated, and posterior cricoid mucosal flap was advanced and sutured anteriorly. Note the thin neo-posterior commissure mucosa, 6 months after surgery (arrowheads).
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today, such as cricoarytenoid joint reconstruction, microscopic flap transfer, and advanced suturing.
Biologic medical treatment Advanced biological therapy may prevent contraction and restenosis after surgical repair by delaying fibrosis and promoting early epithelization.
DISCUSSION Glottic stenosis is a heterogenous group of medical conditions, sharing a common pathway of progressive airway compromise. Anterior and posterior glottic stenosis differs in many aspects and should be discussed separately. Anterior stenosis will cause breathing difficulties only in relatively severe cases because the arytenoids’ motion is infrequently impaired by membranous cord fusion. Posterior stenosis will cause severe dyspnea even in early stages as the arytenoids are fused in the midline. Voice impairment, on the other hand, will be worse with anterior stenosis compared with posterior stenosis, as in the latter the vibratory portion of the vocal folds is preserved. Intervention in posterior glottic stenosis is often mandatory, whereas in anterior stenosis it is optional. Nowadays, most anterior glottic stenosis cases can be repaired endoscopically with local flaps or grafts. In refractory or severe cases, an open procedure with stenting will achieve high success rates. Posterior stenosis is more challenging because of the complex three-dimensional structure of the posterior commissure, especially the cricoarytenoid units. Surgery should focus on restoring the function of at least one cricoarytenoid unit and avoid destructive actions as much as possible. The use of a posterior pharyngeal flap has proven itself as a reliable procedure in restoring function and can often be performed endoscopically. In cases of endoscopic failure, fibrosis of the flap or difficult exposure, the open approach should be used, via laryngofissure, as well as grafting and stenting. When restoring normal function is impossible, destructive procedure such as cordectomy, cordotomy, or arytenoidectomy may be considered. As a rule, it is better to perform these procedures on the less mobile arytenoid and the less pliable vocal fold. The degree of fixation and scarring can be assessed intraoperatively by palpation. The surgeon must make sure the patient is prepared and that the expectations are practical. Treatment in this case is a process, not a ‘‘one-shot’’ solution. Multiple procedures are often required as stenosis tend to recur. The surgeon should be open minded and consider changing strategy in case of repeated failures. In all stages of management, tracheostomy is a legitimate short- or long-term solution. This should be considered especially in cases of repeated failed surgical attempts and with regard to the patient’s general condition and comorbidities. Patient preferences are of major importance. In some cases, a tracheostomy with voice preservation and prevention of aspiration will be the preferred solution.
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CONCLUSIONS There are no accurate guidelines in determining which procedure best fits each individual case. The surgeon must be familiar with diagnostic techniques, anesthetic approaches, and all surgical options. More than 150 years after it was first reported, glottic stenosis still remains one of the most challenging conditions facing the laryngeal surgeon.
Acknowledgments Prof. Reuvit Halperin is acknowledged for scientific and linguistic counseling. Sharon Manker is acknowledged for medical editing. Dr. Hagit Shoffel-Havakuk is acknowledged for her original drawings (Figures 1, 2, and 5). The authors do not have a financial relationship with the organization that sponsored the research.
REFERENCES 1. Kirchner JA, Joseph H. Ogura Memorial Lecture. The vertebrate larynx: adaptations and aberrations. Laryngoscope. 1993;103:1197–1201. 2. McIlwain JC. A historical overview of the aetiology and treatment of laryngeal stenosis. Arch Otorhinolaryngol. 1989;246:336–340. 3. Figi FA. Chronic stenosis of the larynx with special consideration of skin grafting 1940. Ann Otol Rhinol Laryngol. 1994;103(4 Pt 1):249–264. 4. Liu H, Chen JC, Holinger LD, Gonzalez-Crussi F. Histopathologic fundamentals of acquired laryngeal stenosis. Pediatr Pathol Lab Med. 1995;15: 655–677. 5. Montgomery WW, Gamble JE. Anterior glottic stenosis. Experimental and clinical management. Arch Otolaryngol. 1970;92:560–567. 6. Montgomery WW. Posterior and complete laryngeal (glottic) stenosis. Arch Otolaryngol. 1973;98:170–175. 7. Hoasjoe DK, Franklin SW, Aarstad RF, Day TA, Stucker FJ. Posterior glottic stenosis mechanism and surgical management. Laryngoscope. 1997; 107:675–679. 8. Volpi D, Lin PT, Kuriloff DB, Kimmelman CP. Risk factors for intubation injury of the larynx. Ann Otol Rhinol Laryngol. 1987;96:684–686. 9. Bogdasarian RS, Olson NR. Posterior glottic laryngeal stenosis. Otolaryngol Head Neck Surg (1979). 1980;88:765–772. 10. Hillel AD, Benninger M, Blitzer A, et al. Evaluation and management of bilateral vocal cord immobility. Otolaryngol Head Neck Surg. 1999;121: 760–765. 11. Gardner GM. Posterior glottic stenosis and bilateral vocal fold immobility: diagnosis and treatment. Otolaryngol Clin North Am. 2000;33:855–878. 12. Monnier P, George M, Monod ML, Lang F. The role of the CO2 laser in the management of laryngotracheal stenosis: a survey of 100 cases. Eur Arch Otorhinolaryngol. 2005;262:602–608. 13. Riffat F, Palme CE, Veivers D. Endoscopic treatment of glottic stenosis: a report on the safety and efficacy of CO2 laser. J Laryngol Otol. 2012;126: 503–505. 14. Hsieh MJ, Liu YH, Yueh YS, Ko PJ. Use of microdebrider in glottic stenosis following airway stenting. Eur J Cardiothorac Surg. 2006;30:388–390. 15. Mortensen M, Woo P. An underreported complication of laryngeal microdebrider: vocal fold web and granuloma: a case report. Laryngoscope. 2009;119:1848–1850. 16. Temple RH, Timms MS. Paediatric coblation tonsillectomy. Int J Pediatr Otorhinolaryngol. 2001;61:195–198. 17. Ross-Anderson DJ, Ferguson C, Patel A. Transtracheal jet ventilation in 50 patients with severe airway compromise and stridor. Br J Anaesth. 2011; 106:140–144. 18. Ihra G, Hieber C, Schabernig C, Kraincuk P, Adel S, Pl€ochl W, Aloy A. Supralaryngeal tubeless combined high-frequency jet ventilation for laser surgery of the larynx and trachea. Br J Anaesth. 1999;83:940–942.
10 19. Borland LM. Airway management for CO2 laser surgery on the larynx: Venturi jet ventilation and alternatives. Int Anesthesiol Clin. 1997;35: 99–106. 20. Balachandran R, Rahmat O. Endoscopic treatment of glottic stenosis secondary to caustic injury with silastic keel placement: a case report. Med J Malaysia. 2011;66:152–153. 21. Rice DH. Simple keel fixation technique for endoscopic repair of anterior glottic stenosis. J Laryngol Otol. 2008;122:764. 22. Kojima H, Omori K, Shoji K, Kanaji M. Reconstruction of the anterior commissure with a free mucosal flap. Am J Otolaryngol. 1993;14:339–342. 23. Izadi F, Delarestaghi MM, Memari F, Mohseni R, Pousti B, Mir P. The butterfly procedure: a new technique and review of the literature for treating anterior laryngeal webs. J Voice. 2010;24:742–749. 24. Delaere PR, Ostyn F, Segers A, Vandyck W. Epiglottoplasty for reconstruction of posttraumatic laryngeal stenosis. Ann Otol Rhinol Laryngol. 1991; 100:447–450. 25. Xu W, Han D, Hu H, Chen X, Li H, Hou L, Zhang L. Endoscopic mucosal suturing of vocal fold with placement of stent for the treatment of glottic stenoses. Head Neck. 2009;31:732–737. 26. McGuirt WF, Salmon J, Blalock D. Normal speech for patients with laryngeal webs: an achievable goal. Laryngoscope. 1984;94:1176–1179. 27. Xiao Y, Wang J, Han D, Ma L, Ye J, Xu W. Vocal cord mucosal flap for the treatment of acquired anterior laryngeal web. Chin Med J. 2014;127: 1294–1297. 28. Goldberg AN. Endoscopic postcricoid advancement flap for posterior glottic stenosis. Laryngoscope. 2000;110(3 Pt 1):482–485. 29. Goodwin WJ Jr, Isaacson G, Kirchner JC, Sasaki CT. Vocal cord mobilization by posterior laryngoplasty. Laryngoscope. 1988;98(8 Pt 1):846–848. 30. Smith RO, Rooks JJ. Submucosal cordectomy for laryngeal stenosis. Otolaryngol Clin North Am. 1979;12:849–859. 31. Danino J, Goldenberg D, Joachims HZ. Submucosal arytenoidectomy: new surgical technique and review of the literature. J Otolaryngol. 2000;29: 13–16. 32. Mau T, Pletcher SD, Cavanagh PW, Courey MS, Wang SJ. Minicricothyrotomy approach with fiberoptic guidance for management of posterior glottic stenosis. Laryngoscope. 2007;117:1488–1490.
Journal of Voice, Vol. -, No. -, 2014 33. Valdez TA, Wang Z, Schumann R, Shapshay SM. Anterior window laryngoplasty: a new anatomic approach for posterior glottic and subglottic stensosis. Ann Otol Rhinol Laryngol. 2001;110:519–523. 34. Meyer TK, Wolf J. Lysis of interarytenoid synechia (Type I Posterior Glottic Stenosis): vocal fold mobility and airway results. Laryngoscope. 2011; 121:2165–2171. 35. Gaboriau H, Laccourreye O, Laccourreye H, Brasnu D. CO2 laser posterior transverse cordotomy for isolated type IV posterior glottic stenosis. Am J Otolaryngol. 1995;16:350–353. 36. Lim R. Endoscopic CO2 laser arytenoidectomy for postintubation glottic stenosis. Otolaryngol Head Neck Surg. 1991;105:662–666. 37. Crumley RL. Endoscopic laser medial arytenoidectomy for airway management in bilateral laryngeal paralysis. Ann Otol Rhinol Laryngol. 1993; 102:81–84. 38. Lichtenberger G. Endo-extralaryngeal needle carrier instrument. Laryngoscope. 1983;93:1348–1350. 39. Lichtenberger G. Comparison of endoscopic glottis-dilating operations. Eur Arch Otorhinolaryngol. 2003;260:57–61. 40. Rovo L, Jori J, Brzozka M, Czigner J. Minimally invasive surgery for posterior glottic stenosis. Otolaryngol Head Neck Surg. 1999;121:153–156. 41. Rovo L, Venczel K, Torkos A, Majoros V, Sztano B, Jori J. Endoscopic arytenoid lateropexy for isolated posterior glottic stenosis. Laryngoscope. 2008;118:1550–1555. 42. Semmler M, Keck T, Reiter R, Gruen PM. Endolaryngeal posterior mucosal flap for surgical repair of posterior glottic stenosis. Auris Nasus Larynx. 2011;38:608–611. 43. Cobb WB, Sudderth JF. Intralesional steroids in laryngeal stenosis. A preliminary report. Arch Otolaryngol. 1972;96:52–56. 44. Perepelitsyn I, Shapshay SM. Endoscopic treatment of laryngeal and tracheal stenosis-has mitomycin C improved the outcome? Otolaryngol Head Neck Surg. 2004;131:16–20. 45. Zalzal GH, Choi SS, Patel KM. The effect of gastroesophageal reflux on laryngotracheal reconstruction. Arch Otolaryngol Head Neck Surg. 1996;122: 297–300. 46. Hirshoren N, Eliashar R. Wound-healing modulation in upper airway stenosis-Myths and facts. Head Neck. 2009;31:111–126.
The larynx serves multiple vital functions and shares similar units in all mammals, including airway protection during swallowing, breathing coordination, and intrathoracic pressure regulation. Voice production is the latest evolutionary modification.1 The unique functions of the larynx require delicate timing while performing acts and counteracts in extremely short intervals. Glottic stenosis significantly impairs the whole spectrum of these functions. METHODS In this review, we used the PubMed search engine and the authors’ personal experience. The search included up to date studies and historical reports covering different aspects of glottic stenosis, such as basic science, pathogenesis, anesthesia, and surgical techniques. The search used the following keywords: larynx, glottis, airway, and stenosis. Articles discussing Accepted for publication October 22, 2014. From the Department of Otolaryngology - Head and Neck Surgery, Kaplan Medical Center, Rehovot, Israel. 1 Hagit Shoffel-Havakuk and Yonatan Lahav contributed equally to this work. Address correspondence and reprint requests to Yonatan Lahav, Department of Otolaryngology - Head and Neck Surgery, Kaplan Medical Center, P.O.B 1, Rehovot, Israel. E-mail: [email protected] Journal of Voice, Vol. -, No. -, pp. 1-10 0892-1997/$36.00 Ó 2014 The Voice Foundation http://dx.doi.org/10.1016/j.jvoice.2014.10.012
congenital and pediatric stenosis or stenosis extending beyond the glottis were excluded. ETIOLOGY In 1858, Bouchut2 reported croup as a cause of laryngeal stenosis. O’Dwyer and Lefferts in 1890 described diphtheria and syphilis as an etiology. Solis-Cohen contributed a report of stenosis caused by tuberculosis in 1888. Diphtheria was a major concern because of sloughing of the mucosa required repeated interventions and stenosis was the end stage. Less common infectious causes included leprosy, rhinoscleroma, smallpox, measles, pertussis, and blastomycosis.3 In the later 1900’s, trauma became a more prevalent cause, either external or as a result of endotracheal intubation and tracheotomy. Lack (1909) and Jackson (1921) related cricoid damage to urgent tracheotomy performed too high in the trachea. Since the late 1940’s, endotracheal intubation became the most significant etiologic factor, along with other types of trauma such as motor vehicle accidents, laryngeal surgery, or radiotherapy. Table 1 summarized historic and current etiologies for glottic stenosis. HISTOPATHOLOGY AND PATHOGENESIS Whatever the cause, the events leading to glottic stenosis consist of ulceration of mucosa and cartilage, inflammation with granulation, and fibrous contraction.4 Ulceration may occur at varying depth, and granulation will form if the basement membrane is absent. If the epithelium fails to cover the granulation tissue, the latter may continue growing and progress to fibrosis. Annular granulations cause fibrotic scar formation, which contract and tether the vocal folds. Total or partial fixation of the cricoarytenoid joint may follow.
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TABLE 1. Etiologies of Glottic Stenosis Etiology
Examples
Pathogenesis
Traumatic – external Traumatic – internal Traumatic – iatrogenic
Blunt or penetrating Chemical/thermal burn After intubation
Infectious Inflammatory
After laryngeal surgery After irradiation Syphilis, diphtheria Wegener’s
Cartilaginous fractures and mucosal tears Supraglottic and posterior glottic scars Pressure necrosis over interarytenoid mucosa, arytenoids, and cricoid Circular surgical scar Edema, necrosis, fusion of subunits Scar maturation after granuloma formation Granuloma and scarring
SPECIFIC VULNERABLE LARYNGEAL SITES Glottic stenosis is referred to as anterior, posterior, or complete.5,6 The anterior glottis is prone to stenosis if the mucosa on both sides of the anterior commissure is denuded, with scarring causing fusion of the folds. The severity depends on the portion of the membranous vocal fold involved (Figure 1). The posterior glottis is the most vulnerable area to postintubation stenosis because of the pressure placed on the cartilages and the thin mucosa by the endotracheal tube (Figure 2). Convexity of the tube acts as a fulcrum against the posterior glottis. Tracheal angulation increases the pressure of the tube against the nonresistant respiratory epithelium.7 Fourteen percent of patients
FIGURE 1. The normal anterior glottis in a three-dimensional scheme, viewed from posterior to anterior. Note the relations between the vocal folds (VO) and vestibular folds (VE) joining at the anterior commissure. A continuous ‘‘V-shaped’’ mucosal damage in this region (arrow) is the key to late stenotic scar formation; the vocal folds will become fused by the contracting scar during the healing process of such a wound.
intubated for more than 10 days are susceptible to stenosis. Other risk factors include multiple extubations–reintubations, largesized tubes, tube motion, and infection.7 Also, patient-related factors such as diabetes mellitus, congestive heart failure, and a history of stroke or tuberculosis were found to increase the risk of severe laryngeal injury.8 Posterior glottic stenosis was classified into four stages by Bogdasarian and Olson9: type I: adhesion between vocal processes; type II: interarytenoid scar with preserved antero-posterior arytenoids mobility; type III: scar extending to one arytenoid; and type IV: bilateral cricoarytenoid ankylosis. Total glottic stenosis refers to complex conditions involving both the anterior and posterior glottis.
FIGURE 2. The normal posterior glottis in a three-dimensional scheme, viewed from anterior to posterior. Note the vulnerable sites: arytenoids (A), vocal processes (VP), interarytenoid muscle covered by interarytenoid mucosa (IA), and posterior cricoid rim (C). Any mucosal injury involving the interarytenoid compartment along with one or two arytenoids and vocal processes may lead to significant airway compromise due to stenotic scar formation.
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EVALUATION AND WORKUP Workup for glottic stenosis is summarized in Table 2.10,11 The most important aspect of preoperative evaluation would be an awake examination of the patient in the office. The pharyngeal, laryngeal, and tracheal airway should be carefully assessed endoscopically with optimal topical anesthesia. Residual spontaneous mobility of the arytenoids should be assessed and video documented for further follow-up and comparison with postoperative results. Obstruction at other sites other than the glottis must be ruled out before any surgical intervention. INDICATIONS FOR INTERVENTION When a patient presents with respiratory distress and a compromised airway, intervention is mandatory. The form of intervention might be bypassing the stenosed glottis, as in the case of tracheotomy, or reconstruction of the glottis. The treatment strategy should be tailored to the type and degree of stenosis, the etiology and the patient’s needs, and medical history. There is no absolute contraindication for intervention. If possible, treatment should be delayed until the patient is in the best condition, and the causative factors have been controlled and cured. This is the case for infection, granulomatous disease, papilloma, and carcinoma. If uncontrolled, such diseases might be reactivated or grafted to previously unaffected regions.3 TREATMENT STRATEGIES, CONSIDERATIONS, AND CONFLICTS Treating the stenosed glottis should be aimed at restoring cricoarytenoid joints mobility, valve mechanisms, breathing, swallowing, and voicing. Conservative treatment Obese patients can benefit from weight loss. The airway will expand due to parapharyngeal and paraglottic fat loss. Oxygen
3
supplementation may delay respiratory exhaustion. Inflammatory diseases, such as Wegener’s granulomatosis, may respond to anti-inflammatory medications. Bypass Tracheotomy should be considered for temporary or permanent airway relief. A tracheostomy is also advised as a safe airway during a period of consecutive surgical procedures. Endoscopic surgery versus open surgery The endoscopic approach results in less morbidity and allows faster recovery. It is limited in tissue removal and grafting and often requires multiple interventions. Some surgeons believe endoscopic measures should be exhausted first before offering the patient an open procedure. Others suggest that an open procedure is better done as a first resort and not last.3 Stenting Stenting may prevent restenosis and allow for complete epithelial growth. However, the stent itself may cause irritation, leading to the recurrence of stenosis once the stent is removed. Powered instruments These are used for precise tissue removal with better hemorrhage control. CO2 laser12,13 is suitable for scar tissue removal, arytenoidectomy, cordectomy, and flap elevation. Its disadvantages include collateral heat distribution, delayed healing, and granulation formation. Microdebrider can remove excessive granulation and scar tissue14 although they may recur.15 Coblation uses radiofrequency coupled with constant saline irrigation to create an ionized environment which ablates tissue with minimal thermal necrotic damage.16 The authors have treated complex postirradiation glottic and subglottic stenosis using this technique with relative success in maintaining an open airway, sufficient enough for voice production. Further experience and follow-up is required.
TABLE 2. Evaluation and Workup10,11 History Examination
Imaging Polysomnography Laryngeal EMG Pulmonary function tests Blood work
Intubation, neck trauma, laryngeal surgery, irradiation Dyspnea at rest and effort, voice quality, sleep disturbances Dysphonia and stridor, use of accessory respiratory muscles Obesity, surgical scars, tracheotomy site, neck masses Rigid and flexible endoscopic examination of larynx Examination of trachea via the larynx or tracheotomy Multiplanar CT or MRI of the neck The extent of stenosis, proximity of scar tissue to muscle, and cartilage Glottic stenosis can be associated with obstructive sleep apnea Important in perioperative management To differentiate between glottic stenosis and vocal fold paralysis Spirometry and flow curve measures (typically demonstrate variable extrathoracic obstruction) to compare preoperative and postoperative functions Markers of inflammation and autoimmunity
Abbreviations: CT, computed tomography; EMG, electromyography; MRI, magnetic resonance imaging.
4 DEVISING A TREATMENT PLAN WITH THE PATIENT Glottic stenosis may require multiple interventions with a variable degree of relief. The patient must be informed that the different physiological aspects of the normal larynx may not function as efficiently in the reconstructed larynx. He or she must prioritize which of the functions is more important to them. A person that favors his voice may agree to keep a patent tracheotomy and avoid destructive procedure at the glottis, whereas a patient who wishes to avoid a tracheotomy may agree to sacrifice the quality of the voice. ANESTHESIA Airway securing and ventilation can be obtained by transoral intubation, tracheotomy, or jet ventilation. Open surgery will almost always require a tracheotomy. Endoscopic surgery can be performed with an endotracheal tube. The surgeon may have to change the position of the laryngoscope, anterior and posterior to the endotracheal tube, to allow adequate exposure. Tubeless jet ventilation allows for extended endoscopic surgical field without the inconvenience of a tracheotomy.17–19 The air jet is delivered via a narrow cannula, positioned in one of three locations: (1) supraglottic, in conjugation with the operating laryngoscope (Figure 3); (2) subglottic, via translaryngeal cannula or a transcutaneal cannula; and (3) Transtracheal percutaneal cannula. The last may be dangerous in a relatively obstructed larynx as high pressure may develop. The supraglottic approach is the safest and most commonly used.
FIGURE 3. Supraglottic jet ventilation: The jet parameters (frequency, volume, O2%) are set by the generator (asterisk). The jet is delivered by a tube (arrowhead) connected to the suction cannula (thick arrow) of the surgical laryngoscope (thin arrow), which is positioned above the glottis.
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SURGICAL TECHNIQUES Bouchut in 1858 and Schrotter in 1870 used laryngostomy tubes to bypass laryngeal stenosis. O’Dwyer in 1885 and later Rogers in 1905 used a preshaped endolaryngeal tube and placed it in the larynx via the mouth, using force when necessary.2,3 Laryngeal dilators were passed through the mouth for anterior glottic web opening, often painful and unsuccessful.5 In the first major conference on laryngeal stenosis in London in 1909, an open surgical approach was advocated by Lack and Delsaux and gained popularity. Arbuckle introduced a molded plug made of rubber, placed in the new laryngeal lumen, and covered by a skin graft. During the 1930s–1940s, the common practice was laryngofissure, scar removal, skin grafting, and stenting. In 1950, McNaught concluded that epithelization is essential to prevent reformation and introduced the tantalum keel for anterior stenosis repair. Since the 1930’s, endoscopic procedures have also been reported. These included incision of scarred tissue and endoscopic placement of stents. Bouginage was very effective in treating a thin diaphragmatic scar. Jackson and Coats reported intralaryngeal resection and repeated adhesiolysis. This was later abandoned due to multiple recurrences and scarring. Toward the end of the 20th century, the principles of open procedures were still valid, as stated by McIlwain, ‘‘the open approach has stood the test of time.’’ However, over the years, with the increasing experience of the surgeons, improved microsurgical tools and laser technology, a variety of conservative endoscopic procedures have emerged. SURGICAL TECHNIQUES FOR ANTERIOR GLOTTIC STENOSIS Keels and stents Cutting in two stages—one side done in the first procedure and the other side in the next. This strategy may be successful with thin anterior webs. A single stage cutting procedure requires a keel or a flap to prevent reformation. The original tantalum keel described in 1950 was replaced by umbrella-like silicon rubber stents. The procedure starts with endoscopic separation of the web, followed by open midline thyrotomy. The web is incised and a keel is inserted. The external part of the keel is firmly attached to the thyroid cartilage to prevent asynchronous motion and further granulation formation, and the laminas are well fixed to each other to avoid emphysema (Figure 4). Complete epithelization of the incised vocal folds is expected within 9–12 days after surgery. Granulations may develop if the keel is kept longer, as observed in the experimental canine model. The keel should be removed 2–3 weeks after surgery. This can be done in the office under local anesthesia.5 A keel can be introduced and secured endoscopically, sutured to the skin by the Lichtenberger endo-extralaryngeal needle carrier.20 Alternatively, Rice21 suggested securing a stent to the nasal septum rather than to the cartilage or skin to allow safe office removal. Grafts and flaps A free tissue graft can be used as a substitute for an artificial keel.22 The web is separated in a combined endoscopic-open approach. Mucosal graft is harvested from the buccal mucosa
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FIGURE 4. (A) A 72-year-old male with severe anterior glottic stenosis after bilateral cordectomy for squamous cell carcinoma. Note the granulation tissue at the stenotic segment at the anterior commissure (arrows). (B) The web was separated via laryngofissure approach. A silastic keel was positioned between the separated folds and secured to the thyroid cartilage. (C) 1 year after keel removal. Note the reconstructed anterior commissure. The vocal folds are mobile and the airway is safe. and sutured to the anterior commissure region bilaterally, until complete closure is achieved. Another variation is the cartilageperichondrium butterfly graft23 harvested from the thyroid cartilage. Perichondrium is sutured bilaterally, whereas cartilage is secured between the ala. An epiglottic flap can be used in selected cases of a large anterior commissural defect. The epiglottis is released and moved toward the glottis.24 Endoscopic suturing techniques aim to avoid grafting and stenting after lysis.25–27 This is suitable for webs involving up to the entire length of the membranous vocal fold. Webs are incised in the midline and trimmed to allow good adhesion of the mucosa. The free edge of each fold is sutured to achieve mucosal continuity. The authors favor the following technique: the superior epithelium of the web is removed and raw surface is exposed. This is later cut on one side along the free margin of the fold and sutured to the other side. Complete separation is achieved by unilateral suturing (Figures 5 and 6).
Two techniques were reported—membranous and cartilaginous. In the first,30 the posterior glottis is approached using a laryngofissure, and a mucosal flap on the more affected side is elevated. Scar tissue and muscle are resected between the mucosa and cartilage. In the second technique, the same approach is used for submucosal arytenoidectomy.31
SURGICAL TECHNIQUES FOR POSTERIOR GLOTTIC STENOSIS Open resection with grafting and stenting The larynx is entered through a laryngofissure. The scarred mucosa and the interarytenoid muscle are resected. The degree of tissue removal and reconstruction is determined by the type of stenosis. For type I, lysis of the scar tissue may be sufficient. For type II, scar tissue and interarytenoid muscle resection may be necessary, covered by a postcricoid advancement mucosal flap.28 Alternatively, a skin or mucosal graft can be used. For type III, an aryepiglottic flap may be used to cover the defect. In type IV, arytenoidectomy may also be needed. In all cases, an intralaryngeal stent is kept in place for a variable amount of time, ranging from 5 days to 8 weeks.6,7,9,29
Endoscopic lysis Dilatation is the simplest technique but generally not recommended because of a high recurrence rate.9 Midline lysis by cold-steel instruments or laser may be sufficient for type I stenosis9,34(Figure 7). Bilateral transverse cordotomy, anterior to the vocal processes, was described for type IV stenosis. Transverse cutting in a coronal plane at the posterior border of the vocal folds creates triangular widening on each side because of the muscular tension toward the anterior commissure. This allows a wider posterior glottic airway passage.35
Submucosal resection by open laryngofissure approach Submucosal resection is advised to expand the glottic airway while keeping the mucosa intact and avoiding a graft or flap.
Minimal open approach resection Inspection of the posterior glottis with minimal intervention through an open anterior approach may be accomplished by a limited exploration without laryngofissure. A cricothyrotomy approach was offered for lysis of type I interarytenoid band.32 Anterior window laryngoplasty, demonstrated on cadavers,33 has also been suggested for the same purposes, using a mini trapdoor at the midline of the thyroid cartilage. In selected cases, this may avoid possible complications of laryngofissure and the need for tracheotomy.
Endoscopic cordectomy Unilateral cordectomy, performed by laser (as in oncologic resection), can significantly improve the stenotic airway. This can be done either in a submucosal, subligamental, or transmuscular plane. As long as the free edge remains straight and smooth after healing and the contralateral side is kept intact, voice quality is relatively preserved.10,13 Revisions may be required as restenosis often occurs to some degree (Figure 8).
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FIGURE 5. (A) Schematic diagram through an anterior glottic web in coronal plane viewed from posterior to anterior. (B) Dissection and resection of the superior scarred layer of the web. Note the intentional asymmetry in tissue removal more on the upper left side, to allow for optimal positioning of the flap (C) Cut along the inferior right margin of the web. (D) Endoscopic suturing of the right free margin of the flap to the left vocal fold’s edge.
Endoscopic arytenoidectomy Arytenoidectomy may improve the airway while potentially keeping the membranous vocal fold intact. Total arytenoidectomy is not recommended because of significant aspiration and dysphonia. Partial laser arytenoidectomy is more acceptable, from vocal process to medial arytenoidectomy, while preserving the outer rim of the arytenoid36,37 (Figure 9).
Endoscopic scar resection with lateralization After endoscopic scar tissue removal, unilateral lateralization with the Lichtenberger needle carrier38,39 can secure the airway while avoiding stenting or tracheotomy. The vocal fold is sutured to the strap muscles or skin until healing of the posterior commissure takes place. Sutures are removed once arytenoid motion is detected.39,40 In case of an immobile
FIGURE 6. (A) A 56-year-old female with severe anterior glottic stenosis after bilateral vocal fold stripping for Reinke’s space edema. Surgery included removal of upper surface of the web, cut along the right margin, folding and suturing to the left. (B) A month after surgery, note the two sutures (PDS 6/0) along the free edge of the left vocal fold (arrows). (C) Six months after surgery, persistent complete separation of the vocal folds due to the tight epithelial closure on the left side during the surgery.
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FIGURE 7. (A) A 64-year-old female who developed stridor and dyspnea 2 weeks after thoracoscopy with endotracheal intubation for partial esophagectomy. Note the interarytenoid granulation tissue bridge (type I stenosis). (B) The lesion was cut in the middle under topical anesthesia with forceps advanced via the working channel of a transnasal videoendoscope. (C) Three months after the intervention, the arytenoids are free and mobile, with no evidence of residual granulation or stenosing scar.
fixed arytenoid, the cricoarytenoid joint is released and lateralized by a suture in the same technique.41 Endoscopic resection with flap reconstruction Release of the fixed cricoarytenoid joints by resection of the posterior commissure scar tissue, with or without removal of interarytenoid muscle, followed by an advancement of a posterior-cricoid-based mucosal flap toward the exposed region. The flap is sutured to the arytenoid and cricoid mucosal edge. No stent is required (Figure 10). The flap can also be advanced from the aryepiglottic and vestibular folds and rotated to the posterior commissure.42 USE OF MEDICATIONS Several types of medications are used to modulate the different wound healing phases and minimize restenosis after surgery. The three phases of healing consist of inflammation, proliferation, and maturation. Steroids and Mitomycin C are the medications most commonly used. Systemic or locally injected
steroids43 affect the first and the second phases. Mitomycin C applied topically affects the proliferative phase and was suggested in several reports as an effective adjuvant treatment.44 Antireflux medication and antibiotics are advocated by many authors.45 Current data support using steroids, antibiotics, and antireflux medications while the efficacy of Mitomycin C is considered unproven.46
POSTOPERATIVE CARE If the patient does not have a tracheotomy tube, then overnight intensive care unit observation should be considered. The timing of tracheostomy removal depends on the indication for its use. If the patient was tracheotomy dependent before surgery, then often, it should be kept in place for months after surgery. There are no absolute guidelines for timing of stent removal. Influencing factors include the degree of stenosis, type of stent, and the surgeon’s preferences. If the stent is removed before complete epithelization occurs, then restenosis is likely to happen. If the stent is kept too long, then new granulations, necrosis, and
FIGURE 8. (A) A 28-year-old male who developed posterior glottic stenosis 3 months after intermittent traumatic intubation for transient hepatic encephalopathy. The cricoarytenoid joints were fractured and fixed, and the patient was tracheotomy dependent. A series of three endoscopic partial cordectomy on the right side with preservation of the left vocal fold enabled weaning of tracheotomy with sufficient glottic airway (B, inhalation) and good vocal function (C, phonation).
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FIGURE 9. (A) A 68-year-old male with posterior glottic stenosis after multitrauma in motor vehicle accident and prolonged intubation. (B) A left partial arytenoidectomy and cordectomy were performed, and the raw surface was covered by posterior cricoid mucosa (asterisks). Note the improved glottic airway. The patient was weaned off the tracheotomy tube. scarring may develop. Reported stenting duration varies from 5 days to 8 weeks.6,7,9,29,30 A study performed on a canine model showed that the best results are achieved with removal of the stent after 14 days.5 Patients should be followed for years after the procedure because stenosis may recur at any time, especially in patients with chronic inflammatory conditions. FUTURE DIRECTIONS Imaging Higher resolution imaging that discriminates muscles, mucosa, cartilage, and joint capsule from fibrosis may lead to the site of malfunction and better selection of treatment.
Tissue expansion techniques Special devices for cartilage/bone distraction or elongation, inflatable stents, and devices capable of expanding the narrowed lumen may have a role in treatment. Tissue engineering Stem cells replacing scarred tissue with normal elastic mucosa may restore normal function. Advanced endoscopic techniques Three-dimensional vision, delicate surgical tools, and robotic control may allow for complex tasks considered impossible
FIGURE 10. (A) A patient with posterior glottic stenosis due to prolonged intubation after head trauma. (B) The interarytenoid mucosa and muscle were resected, arytenoids were separated, and posterior cricoid mucosal flap was advanced and sutured anteriorly. Note the thin neo-posterior commissure mucosa, 6 months after surgery (arrowheads).
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today, such as cricoarytenoid joint reconstruction, microscopic flap transfer, and advanced suturing.
Biologic medical treatment Advanced biological therapy may prevent contraction and restenosis after surgical repair by delaying fibrosis and promoting early epithelization.
DISCUSSION Glottic stenosis is a heterogenous group of medical conditions, sharing a common pathway of progressive airway compromise. Anterior and posterior glottic stenosis differs in many aspects and should be discussed separately. Anterior stenosis will cause breathing difficulties only in relatively severe cases because the arytenoids’ motion is infrequently impaired by membranous cord fusion. Posterior stenosis will cause severe dyspnea even in early stages as the arytenoids are fused in the midline. Voice impairment, on the other hand, will be worse with anterior stenosis compared with posterior stenosis, as in the latter the vibratory portion of the vocal folds is preserved. Intervention in posterior glottic stenosis is often mandatory, whereas in anterior stenosis it is optional. Nowadays, most anterior glottic stenosis cases can be repaired endoscopically with local flaps or grafts. In refractory or severe cases, an open procedure with stenting will achieve high success rates. Posterior stenosis is more challenging because of the complex three-dimensional structure of the posterior commissure, especially the cricoarytenoid units. Surgery should focus on restoring the function of at least one cricoarytenoid unit and avoid destructive actions as much as possible. The use of a posterior pharyngeal flap has proven itself as a reliable procedure in restoring function and can often be performed endoscopically. In cases of endoscopic failure, fibrosis of the flap or difficult exposure, the open approach should be used, via laryngofissure, as well as grafting and stenting. When restoring normal function is impossible, destructive procedure such as cordectomy, cordotomy, or arytenoidectomy may be considered. As a rule, it is better to perform these procedures on the less mobile arytenoid and the less pliable vocal fold. The degree of fixation and scarring can be assessed intraoperatively by palpation. The surgeon must make sure the patient is prepared and that the expectations are practical. Treatment in this case is a process, not a ‘‘one-shot’’ solution. Multiple procedures are often required as stenosis tend to recur. The surgeon should be open minded and consider changing strategy in case of repeated failures. In all stages of management, tracheostomy is a legitimate short- or long-term solution. This should be considered especially in cases of repeated failed surgical attempts and with regard to the patient’s general condition and comorbidities. Patient preferences are of major importance. In some cases, a tracheostomy with voice preservation and prevention of aspiration will be the preferred solution.
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CONCLUSIONS There are no accurate guidelines in determining which procedure best fits each individual case. The surgeon must be familiar with diagnostic techniques, anesthetic approaches, and all surgical options. More than 150 years after it was first reported, glottic stenosis still remains one of the most challenging conditions facing the laryngeal surgeon.
Acknowledgments Prof. Reuvit Halperin is acknowledged for scientific and linguistic counseling. Sharon Manker is acknowledged for medical editing. Dr. Hagit Shoffel-Havakuk is acknowledged for her original drawings (Figures 1, 2, and 5). The authors do not have a financial relationship with the organization that sponsored the research.
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