The Stent That Went Too Far: Ascending Colon Perforation Following Gastric Stent Migration

A 32-year-old male patient presented with symptoms of gastric outlet obstruction secondary to distal gastric adenocarcinoma. A fully covered self-expanding metal stent (SEMS) measuring 20 mm × 130 mm was placed to relieve obstruction and restore oral intake, with the aim of optimizing the patient for planned perioperative chemotherapy. The patient subsequently received neoadjuvant FLOT (fluorouracil, leucovorin, oxaliplatin, and docetaxel) chemotherapy as per recommendations of the multidisciplinary team and completed three cycles uneventfully. Before scheduled restaging imaging and completion of the fourth cycle, he developed sudden-onset abdominal pain with signs of generalized peritonitis. Imaging revealed pneumoperitoneum, and an emergency exploratory laparotomy was performed. Intraoperatively, a perforation was identified in the ascending colon near the hepatic flexure. A right hemicolectomy was carried out. Histopathological examination demonstrated a foreign body consistent with a migrated stent embedded at the perforation site, confirming complete transintestinal migration of the gastric stent as the cause of colonic perforation. This case highlights a rare but serious complication of fully covered gastric SEMS, particularly in patients receiving neoadjuvant chemotherapy, and emphasizes the need for clinical vigilance even in the absence of interim symptoms.