Retroperitoneal gas gangrene after colonoscopic polypectomy without bowel perforation in an otherwise healthy individual: report of a case

Background: Abdominal gas gangrene caused by clostridia species is rare and usually associated with organ perforation, immune suppression, or advanced malignoma. Case report: A 61-year-old man was admitted with severe back pain 1 day after uncomplicated colonoscopic polypectomy. With the exception of preexisting minor depression, the patient had been previously in excellent health. The computed tomography scan showed retroperitoneal emphysema in the left psoas muscle. During exploratory laparotomy, a spreading retroperitoneal phlegmon with pneumoretroperitoneum and a secondary peritonitis were found. A macroscopic perforation of the gut, particularly at the polypectomy sites was excluded. After the operation, the patient evolved in a septic shock condition and had pulmonary failure. Before hyperbaric oxygen therapy could be employed, the patient died. The autopsy showed a massive gas gangrene of the retroperitoneum caused by Clostridium perfringens, but no macroscopic bowel perforation was detected. Results: This is the first report of a case of gas gangrene after uncomplicated polypectomy without macroscopic perforation in an otherwise healthy individual. A microperforation due to mucosal defect after polypectomy was most likely the entry point for the bacteria. Conclusion: We conclude that clostridial myonecrosis should be considered in unclear abdominal infections, even if the patient's history is not typical as in the present case.