Retroperitoneal hematoma from lumbar artery as an unusual complication after rectal perforation with massive retroperitoneal emphysema.

The patient was a 54-year-old woman diagnosed with adult Still's disease, undergoing high-dose steroid and immunosuppressant therapy for 5 years, who was admitted to our hospital with abdominal pain. Computed tomography (CT) revealed pneumoperitoneum around the rectum and a large quantity of retroperitonal emphysema around the inferior vena cava, aorta and left kidney. An emergency laparotomy was performed. Intraoperative observation revealed a perforation on the mesenteric side of the rectum due to diverticulum, and Hartmann's operation was performed. Deep tenderness and anemia were observed 4 days postoperatively. CT revealed extravasation in the left retroperitoneal space and a retroperitoneal hematoma, and emergency embolization of lumbar arteries was performed. Retroperitoneal bleeding associated with peritonitis after surgery is very rare. We surmised that higher-dose immunosuppressive therapy and gastrointestinal perforation with emphysema in the retroperitoneum induced lumbar artery bleeding. Clinicians should consider these factors as a potential cause of retroperitoneal hematoma.