Unexpected segmental terminal ileal ischemia after colorectal endoscopic submucosal dissection-related sigmoid perforation: a case report

Colorectal endoscopic submucosal dissection (ESD) enables en bloc resection of selected superficial colorectal lesions but is technically demanding and may be complicated by perforation. Diffuse mucosal cyanosis and poor luminal distension during ESD are nonspecific findings that warrant procedural reassessment. A frail 75-year-old woman with low body weight (33 kg) and an approximately 4-cm laterally spreading tumor in the sigmoid colon underwent colorectal ESD. A small iatrogenic perforation occurred during submucosal dissection and was managed with hemoclips. After apparent endoscopic closure, diffuse mucosal cyanosis extending beyond the perforation site and poor luminal distension despite carbon dioxide insufflation were observed. ESD was discontinued before complete lesion resection, tattoo localization was performed, and emergency surgical consultation was obtained. Emergency laparoscopic anterior resection with natural orifice specimen extraction and segmental small-bowel resection identified a clearly demarcated ischemic segment of the terminal ileum, approximately 15 cm in length. Pathological examination confirmed ischemic bowel disease with mural hemorrhagic infarction. The first venous blood gas sample was obtained after anesthesia induction; lactate was within the reference range in three samples obtained from 18:27 to 22:16. No blood gas sample was obtained during the intra-ESD warning period. The postoperative course was uneventful, and the patient was discharged without fever, anastomotic leakage, wound infection, or reoperation. Diffuse mucosal cyanosis and poor luminal distension during colorectal ESD are nonspecific warning signs that should prompt immediate procedural reassessment and consideration of termination and surgical consultation. This case does not establish them as predictors of remote small-bowel ischemia.