Case of colon perforation due to segmental absence of intestinal musculature accompanied by cancer treated with colonic resection and anastomosis.

Background: Segmental absence of intestinal musculature (SAIM) is a partial defect of intestinal muscularis propria without diverticulum. Many reports indicate that the increase in intestinal pressure caused by enemas or endoscopic examinations leads to bowel perforation, but there are few reports involving malignant tumors. Moreover, few reports have had good outcomes after performing one-stage intestinal anastomosis.

Case presentation: A 60-year-old male came to the office with right-side abdominal pain, and was diagnosed with acute generalized peritonitis caused by ascending colon perforation. Emergency laparotomy was performed, and oval and smooth perforation at the ascending colon was observed, which caused ascites with feces. In addition, there was a tumor on the distal side. The terminal ileum was not dilated, so the cause of the perforation was more likely the SAIM-related thin intestinal wall rather than increased internal intestinal pressure due to obstruction of the tumor. Therefore, a right hemicolectomy with functional end-to-end anastomosis (FEEA) between the ascending colon and ileum was performed, rather than creating a stoma. On pathological examination, the resected bowel segments had a partial defect of intestinal muscularis propria around the perforation, leading to the diagnosis of SAIM. The patient had a favorable postoperative course without anastomotic issues and was discharged safely.

Conclusions: This case implies that initial intestinal anastomosis can be performed without creating a stoma when SAIM is suspected from the shape of the perforation and proximal intestine. This case report suggests surgeons should keep SAIM in mind during operations for colon perforations.