Supplementary Material for: Case Report: Successful management of malignant colostomy stenosis using a self-expandable stent with external exposure

A 62-year-old man underwent sigmoid colectomy (pT4aN1bM0) for sigmoid colon cancer. One year after surgery, he developed peritoneal dissemination, leading to bowel obstruction. To manage this condition, a colostomy was created, and chemotherapy was initiated. However, two years postoperatively, he experienced bowel obstruction due to peritoneal dissemination around the colostomy site. The stenosis was located 2 cm oral to the stoma, and although temporary decompression was achieved using an ileus tube and a Nelaton catheter, the obstruction recurred immediately after their removal.
Given his poor general condition and the presence of ascites, colostomy revision was considered but ultimately deemed unfeasible. As a result, we opted for endoscopic placement of a self-expandable metallic stent (SEMS) as a palliative measure. Initially, a covered SEMS (20×60mm) was selected and deployed, ensuring that its distal end was positioned within the colostomy to prevent migration. However, on the following day, the stent migrated in an oral direction, leading to a recurrence of obstruction.
To address this issue, we placed an additional uncovered SEMS (22×60mm) inside the existing stent and extended its distal end externally beyond the colostomy. This approach successfully prevented further migration and ensured continuous decompression. Following the procedure, the patient was able to resume oral intake by postoperative day 2 and was discharged home on postoperative day 8 without any complications related to the SEMS.
This case highlights the effectiveness of SEMS placement for malignant colostomy stenosis. Specifically, exposing the distal end of the SEMS externally may serve as a useful strategy to ensure reliable decompression and prevent stent migration. This method may be considered a viable alternative when colostomy revision is not feasible due to poor general condition or other contraindications.