Post-tuberculosis tracheobronchial stenosis: long-term follow-up after self-expandable metallic stents placement and development of a prediction score—the Restenosis Score

Background The insertion of self-expandable metallic stents (SEMS) for post-tuberculosis tracheobronchial stenosis (PTTS) was controversial. This study aimed to evaluate the efficacy and safety of SEMS for treating PTTS, and developed a scoring system for predicting the occurrence of restenosis after stenting in PTTS patients. Methods We conducted a retrospective review of 87 patients who were diagnosed with PTTS and experienced SEMS insertion between January 2000 and December 2017. All procedures were performed via flexible bronchoscopy under conscious sedation and local anesthesia. Results A total of 85 SEMS were successfully placed in 77 patients. Comparing with pre-stenting, there were significant improvements in the lumen diameters of the stenotic segment, mMRC scale and lung function after short-term SEMS placement. During the long-term (average 163.32 months) follow-up, 48 patients (62.3%) did not develop restenosis after stenting; the other 29 patients (37.7%) developed and eventually, 12 remained under interventional therapies and 11 had bronchial atresia. Multivariate Cox regression analysis revealed that the difference value between SEMS length and the stenosis-segment length, stenosis type, and the number of pre-stenting thermal ablation were independently related to restenosis occurrence and were subsequently used to establish the Restenosis Score. The model's development group (0.83, 95% CI 0.74-0.92) and external validation set (0.94, 95% CI 0.77-1.00) showed excellent discrimination. Conclusion SEMS placement could serve as a safe and effective treatment option for most patients with PTTS. Further, we built a prediction model depending on the independent predictors of restenosis occurrence, the Restenosis Score. This validated tool might provide a decision support and a better management for PTTS patients who underwent SEMS implantation. Keywords: Airway stenosis, Self-expandable metallic stents, Tuberculosis, Restenosis, Prediction