In highly selected patient populations, flexible and rigid endoscopic (endobronchial) management offers effective treatment options for benign major airway disease (e.g., stenosis and malacia). These treatments are associated with less morbidity than traditional surgical interventions. Selection criteria focus primarily on candidacy for more definitive surgical therapy, as patients can be deemed inappropriate candidates for classic resection/reconstruction for a variety of reasons: etiology, extent of disease, failed prior operation, confounding medical comorbidities, and patient preference. Lack of technical expertise at a given institution also may be a factor. Since each institution carries its own bias with respect to these parameters, a patient determined inoperable at one center, in fact, may be considered a reasonable candidate at another.

Clearly, some individuals will benefit greatly from less invasive management of their airway disease. Only rarely is acute life-threatening airway compromise (≥75% luminal compromise) encountered in clinical practice. Moreover, as an alternative to tracheostomy, immediate endoscopic palliation of a high-grade stenosis may be part of a treatment strategy that ultimately incorporates an elective staged resection.

Symptomatic subglottic and tracheal stenoses and tracheomalacias are indications for endoscopic therapy in benign upper airways disease. These etiologies are listed in Table 55-1. Whether used as the primary therapy or as an adjunct to definitive surgery, the goal of endobronchial intervention is to restore airway patency and to provide a durable response, while limiting morbidity. Procedures often involve collaboration between surgeons and interventional bronchoscopists. Critical elements of endoscopic treatments are appropriate patient selection, choice of a specific endobronchial intervention based on indication, focused postoperative care (often including steroid therapy and mucolytics), and anticipation of possible repeated interventions.

The goal of the endoscopic approach is to preserve the respiratory epithelium, while minimizing radial thermal and mechanical injury to the airway. Many procedures can be performed through an adult flexible bronchoscope (video or fiberoptic), although because of the frequent requirement for rigid bronchoscopy, skill with rigid instrumentation is mandatory and must be actively maintained. General anesthesia is generally indicated, although it is possible to perform limited interventions in a bronchoscopy suite with conscious sedation and topical analgesia. Availability of a suitable procedure room (interventional bronchoscopy suite) or an operative room to perform interventions is essential. The suite should contain several high-resolution monitors, endobronchial ultrasound capability (EBUS), mobile flexible bronchoscopy towers, and fluoroscopic capability.

The subglottis lies between the vocal cords and the proximal trachea. Congenital subglottic stenosis generally presents early in life and is characterized by an audible biphasic stridor or a persistent or recurrent croup-type cough. Historically, congenital subglottic stenosis required tracheotomy in over 40% of patients as an early palliative maneuver.¹

Acquired subglottic stenosis is commonly associated with antecedent trauma, either externally (e.g., blunt-force injury to the anterior neck) or, more frequently, internally. There is little doubt that this process represents an important, often delayed, morbidity of laryngotracheal intubation. Internal airway injury can occur as a result of direct mucosal trauma sustained during intubation, endotracheal tube cuff pressure ischemia and mucosal necrosis, constant tube motion and mechanical abrasion, and associated tracheitis.² Percutaneous dilatational tracheostomy and laryngotracheal reflux also have been implicated.³

Acquired systemic diseases such as amyloidosis, papillomatosis, tuberculosis, and granulomatosis with polyangiitis (GPA), formerly Wegener’s granulomatosis, also may include subglottic stenosis as a component of the patient’s symptom complex. There is also a rare idiopathic/cryptogenic syndrome, seen almost exclusively in younger women, that manifests as an obstructing subglottic web.^4,5

Fortunately, congenital causes of benign tracheal stenosis are quite rare and include extrinsic narrowing or incomplete development secondary to vascular rings or partial vascular slings. Acquired diseases account for the majority of occurrences. Specifically, intrinsic injuries caused by endotracheal intubation or tracheotomy are the most common and best characterized. Table 55-2 summarizes the four most common locations related to posttracheotomy stenosis.^2,6,7 Healing from direct trauma to the airway can result in a complex, asymmetric scar that can be difficult to palliate. The classic “A-Type” deformity (as opposed to the normal C shape of the trachea) can result from anterior collapse of the proximal trachea at the site of a prior tracheostoma. In addition, some stenoses are accompanied by tracheomalacia, which further complicates their management.

Numerous techniques can be used to relieve central airway stenosis (Table 55-3). Historically, rigid tracheoplasty (dilatation) was the first option for high-grade proximal airway narrowing. More recently, however, although rigid instrumentation is still a critical element in the management of these conditions, endoscopic treatments have become far more common because of the improved optics of flexible bronchoscopes and the development of a vast array of therapies that can be easily used through them. In addition, since a reduced skill-set is required for flexible approaches, dissemination has occurred quite rapidly. Often procedures become an amalgam of both flexible and rigid techniques as rigid scopes provide ventilatory support and stable airway access, whereas flexible scopes are passed within them and provide improved optics.

By far the most common endobronchial intervention, dilatation is seldom performed without another therapy. Depending on the complexity of the stenosis, however, repeated endobronchial dilatations alone may be sufficient to effectively palliate an inoperable airway stenosis. Bougienage (passing a series of graduated bougie tubes through a suspension laryngoscope) is an effective therapy for most simple (web-like) stenoses of the subglottis and proximal trachea. Since the tubes are relatively compliant, this form of rigid tracheoplasty is gentler on the airway than a rigid bronchoscope used to affect the same result. As the complexity of the stenosis increases (i.e., asymmetric, denser scar, component of malacia, and lengthier), rigid tracheoplasty alone becomes far less effective, and its use may lead to significant airway injury. Consequently, prior to any intervention, a thorough assessment of the pathology is mandated.

Unintended disruption of the airway can occur during dilatation because mechanical forces may not be equally distributed during rigid dilatation. If the membranous airway is spared by the pathology, it will be the point of least resistance and may split during the procedure while leaving the stenosis intact. Other weak points in the airway are the membranous–cartilaginous junctions which can dislocate during an undirected rigid dilatation. This potential problem often is overcome by pretreating the stenosis with ablation therapy to create a more controlled dilatation (see below).