Clinical outcomes of secondary stent-in-stent self-expanding metal stent placement for primary stent malfunction in malignant gastric outlet obstruction

Background: Although a substantial number of patients require secondary stents insertion due to primary stent malfunction in malignant gastric outlet obstruction, data on the outcomes of secondary self-expanding metal stents are sparse. Aim: To investigate clinical outcomes and factors related with secondary stent malfunction in patients with malignant gastric outlet obstruction given secondary stent-in-stent self-expanding metal stent insertion. Methods: For this retrospective study, a total 77 patients who underwent secondary stent-in-stent self-expanding metal stent placement for primary stent malfunction in malignant gastric outlet obstruction were enrolled. We compared the effectiveness and complications of secondary covered and uncovered stents and explored the predictive factors for stent malfunction. Results: Stent-in-stent self-expanding metal stent placements were technically successful in all patients. Both groups also had comparable clinical success rates (covered stent, 87.2% and uncovered stent, 90.0%, P= 1.000). Stent malfunction rates (31.9% and 36.7% respectively, P= 0.805) and median patency time of stent (165 [95% confidence interval: 112-218] and 165 [95% confidence interval: 126-204] days, respectively, P= 0.358) were similar between secondary covered and uncovered stents. Longer patients' survival time (≥100 days) was associated with increased risk of stent malfunction (odds ratio: 4.598; 95% confidence interval: 1.473-14.355; P= 0.009). Conclusions: Secondary stent-in-stent self-expanding metal stent placement is feasible and effective treatment for primary stent malfunctions in malignant gastric outlet obstruction. Covered and uncovered stent are equally acceptable in terms of stent-related complications and stent patency, regardless of primary stent type.