You are in: eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > LARYNGOLOGY Laryngeal StenosisArticle Last Updated: Mar 22, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Debbie A Eaton, MD, Neurotology Fellow, Department of Otolaryngology, University of Pittsburgh Debbie A Eaton is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery and American Medical Association Coauthor(s): Alan D Murray, MD, Pediatric Otolaryngologist, ENT for Children; Consulting Staff, Department of Otolaryngology, Medical Center of Lewisville, Children's Medical Center at Dallas, Cook Children's Medical Center; Full-Time Staff, Texas Pediatric Surgery Center, The Pediatric Surgery Center Editors: Clark A Rosen, MD, Director, University of Pittsburgh Voice Center; Associate Professor, Department of Otolaryngology and Communication Science and Disorders, University of Pittsburgh School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Stephen G Batuello, MD, Consulting Staff, Colorado ENT Specialists; Christopher L Slack, MD, Otolaryngology-Facial Plastic Surgery, Private Practice, Associated Coastal ENT; Medical Director, Treasure Coast Sleep Disorders; Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine Author and Editor Disclosure Synonyms and related keywords: laryngeal stenosis, circumferential narrowing of the endolaryngeal airway, partial narrowing of the endolaryngeal airway, narrowing of the endolaryngeal airway, endolaryngeal airway, supraglottic stenosis, glottic stenosis, subglottic stenosis, supraglottis, glottis, subglottis, larynx INTRODUCTIONSection 2 of 11
  Laryngeal stenosis can be defined as a partial or circumferential narrowing of the endolaryngeal airway and may be congenital or acquired. The type of stenosis is further divided by anatomic location into supraglottic, glottic, or subglottic stenosis, and the subglottis is the most common site of involvement. A formal endoscopic evaluation of the airway in the operating room is an essential part of evaluation. Treatment is dependent on the site of involvement and the degree of stenosis (correlated with the patient's symptoms), and it ranges from endolaryngeal laser surgery and dilations to open surgical repair with graft placement. ProblemCongenital laryngeal atresia may be incomplete or complete. Incomplete atresia consists of a firm fibrous membrane obstructing the glottis. Emergent tracheotomy is necessary. Complete atresia may present as stillbirth. Congenital laryngeal webs account for about 5% of congenital laryngeal anomalies. Seventy-five percent of these are at the glottic level. The rest are at the supraglottic or subglottic level. Congenital laryngeal webs are rare; one report identified 51 children with webs during a 32-year period. Few cases are significant enough to require immediate airway intervention. Laryngeal webs often involve both the glottis and subglottis. The incidence of posterior glottic stenosis is reported to be as high as 15% in patients who are intubated for more than 10 days. Factors that contribute to the increased risk of stenosis following intubation include traumatic intubation, prolonged duration of intubation, multiple extubations and reintubations, use of an oversized endotracheal tube for intubation, motion of the patient or the tube, gastroesophageal reflux, and local infection. Supraglottic stenosis has recently been identified as a factor in chronic upper airway obstruction following tracheotomy or laryngotracheal reconstruction. FrequencyApproximately 15% of patients who are intubated for more than 10 days develop some degree of glottic stenosis. Ninety percent of acquired subglottic stenoses in infants and children are due to endotracheal intubation. The incidence of subglottic stenosis after intubation is reported to be 1-10%. Congenital glottic stenosis is a rare disorder and may exist as a thin membranous stenosis, as a thick anterior or posterior web, or as a complete fusion of the vocal cords. Congenital laryngeal webs are rare; one report identified 51 children with webs during a 32-year period. EtiologyCauses of laryngeal stenosis include the following:
As a result of technological improvements, more premature infants are surviving due to prolonged endotracheal intubation. This now is the primary cause of subglottic stenosis in children, with the percentage estimated at 1-10%. Congenital glottic webs and subglottic stenosis result from failure of the laryngeal lumen to recanalize. During normal development, the laryngeal lumen is obliterated by continued growth of the arytenoid masses and hypobranchial eminence. By the tenth week of gestation, the laryngeal lumen is reestablished when this condensation is recanalized. Incomplete recanalization results in various degrees of glottic and/or subglottic stenosis. Acquired glottic stenosis most commonly is due to trauma secondary to endotracheal intubation. Other causes include caustic ingestion, infections (such as croup), foreign bodies, external trauma, and iatrogenic causes due to surgery on the larynx. Long-term nasogastric intubation also may contribute to mucosal erosion and ulceration in the postcricoid region, progressing to posterior glottic stenosis. Supraglottic stenosis or collapse is thought to be due to disruption of the supraglottic lymphatics and/or relaxation or injury to the suspensory muscles of the hyoid bone and hyoepiglottic ligament. Such disruption may occur during laryngotracheal surgery. ClinicalThe clinical presentation of subglottic stenosis is variable depending on the age, medical condition, and activity level of the patient and the extent of stenosis. Neonates intubated shortly after birth may require multiple intubations and, subsequently, develop subglottic stenosis, which leads to more difficulty in tolerating extubation. Children with mild-to-moderate stenosis may be asymptomatic until an upper respiratory tract infection leads to airway edema that causes further subglottic narrowing. They may have a history of prolonged episodes of recurrent croup despite increasing age. Any child with a history of endotracheal intubation or laryngeal trauma can potentially develop subglottic stenosis. The most common presentation of subglottic stenosis is progressive respiratory difficulty with biphasic stridor and a history of intubation. Sometimes the stridor is only present with agitation or crying. Depending on the degree of obstruction, retractions may also be seen. In general, stenosis that develops gradually is better tolerated than an acute obstruction. Other signs and symptoms include feeding difficulties with poor weight gain, poor phonation, and dyspnea on exertion. Congenital glottic stenosis in the form of laryngeal webs typically presents with symptoms of airway distress or obstruction, a weak or husky cry, and, occasionally, aphonia. These lesions often present shortly after birth and may require emergent intubation or tracheotomy if severe. Seventy-five percent of congenital webs are located at the glottic level (usually anteriorly), with the remainder located in supraglottic and subglottic areas, with occasional extension to the glottic level. Important aspects of the history include an assessment of the patient's dyspnea and stridor. This includes a description of the characteristics of the stridor (inspiratory, expiratory, or biphasic), time of onset, course, and relieving or aggravating factors. The history must also be used to determine any possible etiological factors, such as a history of prolonged intubation, prior surgery (airway or otherwise), trauma, or caustic ingestion. The larynx is divided into 3 distinct anatomical sites: the supraglottis, glottis, and subglottis. Subglottic stenosis is the most common form of laryngeal stenosis and may be congenital or acquired. Acquired subglottic stenosis is more common than congenital and is usually due to prolonged endotracheal intubation. In the absence of a history of intubation or other acquired cause of stenosis, congenital subglottic stenosis is diagnosed. Congenital subglottic stenosis may be divided into 2 types: membranous and cartilaginous. Some cases of acquired stenosis may have an underlying congenital component. Glottic stenosis may be found in conjunction with subglottic stenosis or as a separate entity. It may be a congenital or an acquired process and is represented as anterior or posterior webs, interarytenoid adhesions with or without impaired vocal cord mobility, or, rarely, complete fusion of the true vocal folds. Acquired posterior glottic stenosis, typically resulting from trauma due to endotracheal intubation, is by far the most common form of glottic stenosis. Congenital glottic stenosis is a rare disorder and may exist as a thin membranous stenosis, as a thick anterior or posterior web, or as a complete fusion of the vocal cords. Supraglottic stenosis is rare and has only recently been described as a distinct entity. It is usually related to prior laryngotracheal surgery or trauma. Voice quality and demands should be assessed in the adult patient. Similarly, respiratory symptoms and demands (eg, dyspnea on exertion) should be evaluated. Classification The extent of posterior glottic stenosis has been classified into 4 types by Bogdasarian and Olson. Stenosis increases in severity as follows:
In general, posterior glottic scarring tends to present with dyspnea, and anterior glottic scarring produces dysphonia. Acquired posterior glottic stenosis usually presents as difficulty on extubation or tracheotomy dependence, with a history of airway difficulty requiring intubation. In children, supraglottic stenosis or collapse typically presents as persistent upper airway obstruction following tracheotomy or laryngotracheal reconstruction. This problem has recently been identified as a major factor in preventing decannulation following laryngotracheal reconstruction in the pediatric patient. As such, specific treatment recommendations are not available. INDICATIONSSection 3 of 11
The primary goals of the treatment of laryngeal stenosis are the development of an adequate airway and voice quality preservation or improvement. Treatment can be organized into 4 broad categories.
Treatment of congenital subglottic stenosis depends on the character of the stenosis (membranous or cartilaginous), shape and size of the stenosis, and the state of the cricoid cartilage (normal or abnormal). Congenital subglottic stenosis is usually less severe than acquired stenosis and often can be managed more conservatively. Some patients outgrow the condition, and mild cases of stenosis are managed with a conservative approach consisting of regular follow-up care and aggressive medical management of upper respiratory infections. More severe cases of congenital subglottic stenosis (of the membranous variety) may require endoscopic dilations. Severe cases of cartilaginous stenosis may require open surgical reconstruction. Treatment of acquired subglottic stenosis is adjusted to the age and overall medical condition of the child and the grade of the stenosis (based on percentage of laryngeal lumen obstruction) (see Staging). Treatment of congenital glottic stenosis depends on the thickness of the web. RELEVANT ANATOMYSection 4 of 11
The normal subglottic lumen diameter is 4.5-5.5 mm in the full-term neonate and about 3.5 mm in premature neonates. A subglottic diameter of 4 mm or less in a full-term baby is considered to be narrow. In children, the subglottic region (cricoid cartilage) is the narrowest portion of the airway. It is most susceptible to injury from endotracheal intubation. The proximal subglottic airway is bounded by the thyroid cartilage anteriorly and by the posterior plate of the cricoid cartilage laterally and posteriorly. Distally, the cricoid ring circumferentially surrounds the subglottic airway. This area is lined with pseudostratified ciliated columnar epithelium. The glottic segment of the larynx is composed of the true vocal cords, the anterior and posterior commissures, and the vocal processes of the arytenoid cartilages. The superior border of the glottis is the ventricle (which separates it from the supraglottic region). The inferior border is at the inferior limit of the true vocal cord. The posterior glottis consists of the posterior third of the vocal cords, the posterior commissure with the interarytenoid muscle, the cricoid lamina, the cricoarytenoid joints, the arytenoids, and the overlying mucosa. The anterior glottis is lined with squamous epithelium, and the posterior glottis shares respiratory epithelium with the subglottis. CONTRAINDICATIONSSection 5 of 11
Children with a need for ventilatory support are generally poor surgical candidates. Pulmonary status must be maximized prior to any airway intervention. Children with these problems require a tracheotomy for airway control. Reconstruction in infants and children with a history of bronchopulmonary dysplasia may be deferred until they have experienced a season without hospitalization for severe respiratory illness. Most authors recommend a minimum patient weight of 10 kg before laryngotracheal reconstruction, as this allows adequate growth, maturity of the immune system, and stabilization of pulmonary disease. Control of gastroesophageal reflux and asthma is essential prior to treatment. WORKUPSection 6 of 11
Lab Studies
Imaging Studies
Other Tests
Diagnostic Procedures
Histologic FindingsCongenital subglottic stenosis may be histopathologically classified as cartilaginous or membranous. Membranous stenosis is more common than cartilaginous stenosis and consists of a fibrous soft-tissue thickening of the subglottis due to submucosal fibrosis, submucosal gland hyperplasia, or granulation tissue. This type of stenosis usually is circumferential. The most common type of cartilaginous stenosis is a thickening or deformity of the cricoid cartilage, which causes a shelflike stenosis. Acquired subglottic stenosis may similarly exist as a soft, membranous stenosis or a hard, mature scar. In rare cases of glottic stenosis caused by granulomatous infections or systemic diseases, biopsy is necessary to make the diagnosis. For example, the presence or absence of caseating necrosis or vasculitis differentiates between tuberculosis, sarcoidosis, and Wegener granulomatosis. Identification of causative organisms can also be accomplished using the biopsy specimen. StagingMultiple staging systems exist for subglottic stenosis. The most frequently used system has 4 grades.
TREATMENTSection 7 of 11
Medical therapy
Surgical therapyOverall, the trend in management of glottic and subglottic stenosis is shorter stenting periods and less-invasive techniques, such as endoscopy or a smaller laryngofissure. Glottic stenosisEndoscopic methods Generally, methods that rely solely on dilation are unsuccessful for all except the most translucent membranous webs. In congenital glottic stenosis, the thickness of the web determines the treatment modality; thin webs that transilluminate respond well to endoscopic lysis (either sharply or with a carbon dioxide laser) or serial dilations. Thicker webs may require an open procedure. Recently, endoscopic techniques have been used to perform a posterior cricoid split and rib grafting, with good results. Open methods Open techniques involve an anterior laryngofissure with grafting or placement of laryngeal keels or stents. Thick congenital webs require tracheotomy in approximately 40% of patients with a subsequent open laryngeal repair. Subglottic stenosisEndoscopic methods Soft subglottic stenoses may respond well to serial endoscopic dilations. Endoscopic scar excision with cauterization, cryosurgery, and serial electrosurgical resection has been used with limited success. The carbon dioxide laser can be useful for treating early stenosis with granulation tissue. This treatment may improve the airway without causing significant bleeding or edema. Endoscopic treatment is not successful in cases of the following:
Open methods Grades III and IV subglottic stenosis require open methods. Limited grades I and II may respond to endoscopic treatment but many times benefit from an open procedure. A tracheotomy is often required prior to definitive open surgical repair. Multiple techniques exist for expansion of the airway, combining the use of laryngeal and cricoid splits, cartilage grafts, and stenting. The anterior cricoid split technique is most often used in cases of congenital subglottic stenosis due to a small cricoid ring or localized submucosal fibrosis with a normal cricoid cartilage in neonates who have failed extubation. Anterior cricoid decompression with cartilage grafting is used for anteriorly based subglottic stenosis. A combined laryngofissure with posterior cricoid split is the method of choice for combined posterior glottic and subglottic stenoses, moderate subglottic stenosis with loss of cartilaginous support, and complete glottic and subglottic stenoses. Scar removal is unnecessary in this procedure. Autogenous costal cartilage is the graft material of choice in children when augmentation of cricoid cartilage is needed. Auricular or thyroid ala cartilage may be used in selected cases. Stents are used to hold the reconstructed area in place and are necessary when using grafts to expand stenosed areas of the airway. The airway may be stented postoperatively with an endotracheal tube, or a molded silicone or Teflon stent may be placed intraoperatively. Partial cricotracheal resection can be performed in cases of severe circumferential subglottic stenosis. Patients with vocal cord paralysis may require more than one procedure prior to decannulation, but overall decannulation rates with cricotracheal resection are high. Preoperative detailsOptimization of preoperative pulmonary status is essential. Preferably, patients should be off oxygen supplementation and ventilatory support. Gastroesophageal reflux must be adequately treated to minimize formation of granulation tissue. Preoperative evaluation includes awake indirect or fiberoptic laryngoscopy to evaluate vocal cord mobility. The extent and character of the stenosis is further assessed with microsuspension laryngoscopy and bronchoscopy while the patient is under anesthesia. Palpate the arytenoids to determine immobility of the cricoarytenoid joints. Size the airway using endotracheal tubes. Bogdasarian and Olson have classified the extent of posterior glottic stenosis into 4 types. Stenosis increases in severity as follows:
Arytenoidectomy has been recommended in cases of joint fixation. Cartilage grafts can be placed in the anterior cricoid, posterior cricoid, or both to expand the airway. Intraoperative detailsGlottic stenosisSmall anterior webs less than 2-3 mm wide that produce minimal or no symptoms do not generally require surgery. The key to successful repair of webs is the adequate coverage of denuded surfaces. Endoscopic methods The tissue is dilated with round smooth dilators, and systemic steroids are often supplemented. Thin anterior webs may be managed successfully by microendoscopic incision of the web with a knife or carbon dioxide laser. The procedure should be staged for each side separately to avoid recurrence. Endoscopic keel placement in children is generally unsuccessful. In contrast, most glottic stenosis in adults can be treated endoscopically with or without a keel. Posterior glottic stenosis may be divided endoscopically if it is due to a simple interarytenoid adhesion with a mucosally lined sinus tract present posteriorly. Scarring involving the cricoarytenoid joints requires open techniques. Open methods Tracheotomy with laryngofissure and keel placement is necessary in cases of longer, thick, anterior glottic scars. Scar resection should be kept to a minimum to reduce mucosal loss. A keel is placed to prevent restenosis in the anterior commissure during reepithelialization. The keel is designed to avoid contact with the posterior glottis to minimize scarring. Bilateral vocal cord paralysis associated with acquired glottic stenosis requires an arytenoidectomy with vocal cord lateralization in addition to correction of the glottic stenosis. Open techniques require a laryngofissure with web division and coverage of the raw area with various flaps. Investigational techniques involve an anterior window laryngoplasty, which may become favorable to traditional open techniques. This method is expected to provide closer and more direct exposure than endoscopic techniques and to carry fewer possible complications than traditional laryngofissure. Posterior glottic fixation has been treated by scar incision, posterior cricoidectomy with stenting, and cartilage grafting with good airway and voice outcomes. Described by Zalzal in 1993, this technique involves an anterior laryngofissure with incision of the posterior glottic scar in the midline, posterior vertical cricoidectomy down to the hypopharyngeal mucosa, and cartilage grafting between the arytenoids. A one-stage procedure for the repair of major congenital laryngeal webs with associated subglottic stenosis has been used successfully in 5 children. This technique, reported by Biavati et al, involves anterior laryngofissure that includes division of the web with careful mucosal coverage of raw surfaces, submucous resection of the area of stenosis, costal cartilage grafting, and postoperative endotracheal tube stenting for 5-7 days. Subglottic stenosisEndoscopic methods Gentle periodic endoscopic dilation with well-lubricated, round, tracheal dilators has been recommended to treat soft congenital subglottic stenoses. The carbon dioxide laser is most frequently used in cases of early stenoses with granulation tissue, thin circumferential webs, and crescent-shaped bands. Microcauterization and cryosurgery have fallen into disfavor due to inconsistent results. Open methods Open techniques generally are required for grade III and IV stenoses and many grade II stenoses. These techniques may be classified broadly into splits, augmentations, and resections. The anterior cricoid split procedure generally is performed on a neonate who meets certain specific criteria. The procedure is used to avoid tracheotomy in neonates. A median vertical incision is made through the first 2 tracheal rings, cricoid cartilage, and the bottom one-third of the thyroid cartilage. The split permits distraction of the cricoid ring up to 3 mm with an endotracheal tube stenting the laryngeal framework for 7-14 days postoperatively. Other split procedures consist of posterior and lateral divisions of the cricoid. Augmentation procedures are required when distraction of the laryngeal framework greater than 3 mm is necessary. Autogenous costal cartilage is the graft material of choice in children because of its size and rigidity. A 4-cm section of the fifth rib is routinely obtained. This technique can be performed as a single-stage laryngotracheoplasty with postoperative stenting by a nasotracheal tube or as a 2-stage procedure, leaving the tracheotomy in place and placing an endolaryngeal stent. The larynx may be augmented anteriorly, posteriorly, or both, but the most common procedure involves an anterior cartilage graft. A cartilage graft in the posterior glottis or subglottis may be necessary in cases of posterior glottic stenosis, subglottic stenosis, or both; isolated subglottic shelves; circumferential subglottic stenosis; and total or near-total obstruction at the glottic or subglottic level. Stents are used to provide stability to the reconstructed airway, counteract scar contractures, and promote a scaffold for epithelium to cover the lumen of the airway. Stenting is necessary when a graft has been used to expand the airway. The most commonly used stent is the endotracheal tube. Duration of stenting depends on the function of the stent. Nasotracheal tubes after single-stage laryngotracheoplasty are typically removed after one week. When the larynx has been distracted but not grafted stenting is usually required for 3-6 months. The Cotton-Lorenz stent (rigid Teflon) is commonly used in children because it is inert, does not adhere to tissue, and provides firm support. Short-segment severe stenoses of the cricotracheal region may be resected with partial resection of the anterior cricoid and primary anastomosis. This procedure is for cases of isolated severe subglottic or upper tracheal stenosis with a normal lumen of at least 10 mm below the glottis but can be combined with other procedures. The dissection is performed in the subperichondrial plane to resect cricoid cartilage, if needed. The risk of recurrent laryngeal nerve injury is present because of its proximity to the resected portion. Many times, stenting is not necessary. Postoperative detailsExcellent intensive care unit support is absolutely essential to the success of open laryngeal surgery, particularly with single-stage procedures.
Follow-up
COMPLICATIONSSection 8 of 11
Emergent complications include airway obstruction, stent aspiration, hematoma formation, and pneumothorax.
Other potential complications vary according to the technique used for treatment and include recurrence, aspiration, infection, keel extrusion, chondritis, granulation tissue formation, dysphonia, and tracheotomy dependence. OUTCOME AND PROGNOSISSection 9 of 11
Involvement of the glottis in subglottic stenosis has been found to have an unfavorable effect on outcome, although isolated glottic stenosis tends to have a significantly better outcome when compared with other areas of laryngeal stenosis. Voice outcomes vary according to the method of treatment and degree of stenosis but generally are unchanged or improved. The anterior cricoid split procedure consistently yields a higher than 70% success rate (decannulation) when specific criteria are followed. In 16 patients undergoing partial cricotracheal resection with primary anastomosis for grade III or IV subglottic stenosis, Stern et al report a 94% decannulation rate. Younis et al report a series of 21 pediatric patients undergoing single-stage laryngotracheal reconstruction, with anterior rib grafts, without stenting, and with immediate postoperative extubation in 20 of 21 patients. FUTURE AND CONTROVERSIESSection 10 of 11
Stent placement, duration, and material are controversial issues. Postoperative movement of the arytenoids on a stent may have a negative effect on the healing process. Mitomycin-C application has been investigated extensively in canine models of subglottic stenosis, and has shown promising anecdotal results in human subglottic stenosis and in tracheal stenosis. REFERENCESSection 11 of 11
Article Last Updated: Mar 22, 2006 |
