Repositioning of migrated self-expanding metallic tracheobronchial stent: predictors of a successful maneuver and its impact on survival

Endobronchial stents are used to treat airway obstruction due to both malignant and benign obstructive diseases of the trachea or bronchi (1,2). In conjunction with the standard management for the underlying primary disease, stents relieve dyspnea and improve overall functional status (3). Stents comes in various shapes and sizes, are made of a wide variety of biocompatible materials, each with unique insertion techniques (4-6). However, the search for the perfect stent remains elusive (7). The heterogeneity of the underlying obstruction—shape, form and etiology and the unique attributes of each of these stents—their tensile strength, thickness, insertion technique, do not allow for a single stent type to be ideal for all situations. Stents are foreign objects and are not bereft of complications (6). These include malposition, stent-fractures stent-migration, airway-perforation, excessive granulation-tissue formation, hemorrhage, bacterial colonization resulting in stent-associated infections, stent obstructions by tumor, granulation tissue or due to mucostasis (8-12). These complications may be life-threatening and hence may justify surveillance bronchoscopy at an interval of 4–6 weeks after placement (12). Migration of a tracheobronchial stent has been reported to occur in several studies (12-15). For our study, we identified stent migration as situations where the final location of the stent was different from its intended location but also produced a suboptimal effect on restoration of airway patency or the specific intended use of the stent. Some studies report migration rates between 20–50% (6,13), whereas others report a much lower rate (<5%) (14). Migration of stents appears to occur more frequently with hybrid stents (12,16) although the others disagree (17,18), in benign strictures (6), with undersized stents (19) and with tubular stents compared to Y-stents (6). A mismatch between the size of the airway and the stent diameter is thought to be one of the factors resulting in stent migration (20). Migrated stents can be repositioned (14). If unsuccessful, such migrated stents may need to be removed. Few studies discuss the technique and impact of such stent repositioning maneuvers (21)