Endoscopic management of post-lung transplantation anastomotic stenosis: metallic, silicone or biodegradable stents

Abstract

We read with great interest and enthusiasm the paper by Lischke et al. [1] on the use of a new biodegradable stent in the treatment of stenosis after lung transplantation. The concept that a stent could act for a certain period of time and then disappear is a very promising concept in airway stenting. This first report in humans is in itself of high scientific value even if the studied population is very limited and if biodegradable stents made of bio-absorbable polydioxanone do not seem to prevent recurrences as suggested by the fact that new stent placement was necessary in almost all of the patients after degradation of the initial stent. This may be due to the fact that the stent degradation is too fast and that this kind of stenosis may require longer stent placement duration. In comparison, posttracheostomy or post-intubation tracheal stenosis, another type of benign airway stenosis, requires an average of 18 months with a silicone stent in place, to be definitely cured in almost 70% of the cases (no recurrence at 1 year after removal) [2]. The absence of silicone stents as potential alternative to metallic stents in this study is questionable for us. Indeed, we recently published our experience using silicone stents to treat anastomotic stenosis following lung transplantations [3]. We treated 23 anastomotic airway stenoses with the Dumon-type stents. Mean stent duration was 266 days (range: 24–1407 days). Stent-related complications were of mild to moderate in severity, and were appropriately managed endoscopically. Successful stent removal was achieved in 16 of 23 cases (69.5%) without recurrence of stenosis. Our conclusions fully support the idea of non-permanent stenting in anastomotic complications after lung transplantations and in benign airway stenoses in general. This does not seem to be really the case with biodegradable stents, given that new stents are regularly required in the studied population. It is always useful to be reminded of the FDA recommendations regarding metallic stenting in benign tracheal stenosis (www.fda.gov/MedicalDevices/Safety/AlertsandNotices/Public HealthNotifications/UCM062115) and the fact that non-fully covered metallic stents can actually worsen the primary stenosis [4] and may be very difficult to remove after placement [5]. Silicone stents are still considered as the gold standard in airway stenting [6] and any new type of stent should be compared with them, even biodegradable stents. As the future of airway stents clearly evolves towards active stents (drug-eluting stents, biodegradable, radioactive stents) [6], the study by Lischke et al. [1] is clearly a landmark study in this field and the authors should be acknowledged for that. Many new studies will be probably published soon with new applications and new kinds of degradable stents, the debate is just starting.