Background
Seminal vesicle-rectal fistula due to anastomotic leakage after laparoscopic low anterior resection (Lap-LAR) for rectal cancer is rare.

Material and Methods
We report a case of seminal vesicle-rectal fistula due to anstomotic leakage after Lap-LAR.

Result
A 73-year-old man underwent Lap-LAR with D2 lymph node dissection for Rb rectal cancer as an additional resection after endoscopic mucosal resection (EMR). A Denonvilliers fascia was partially resected. Histopathological examination of the resected rectum revealed no residual adenocarcinoma and no regional lymph-node metastasis. We removed rectal tube on postoperative day (POD)3 and the drain on POD4. The patient developed a fever without symptoms of peritonitis on POD5, and was diagnosed with anastomotic leakage by a water- soluble contrast enema on POD6. On POD13 an abdominal CT scan demonstrated emphysema in the seminal vesicle. He was diagnosed with seminal vesicle and rectal fistula secondary to anastomotic leakage in computed tomography. Diverting ileostomy by single-site laparoscopic surgery was created on POD 22. The cure of the fistula was confirmed by a water-soluble contrast enema 8months postoperatively, and thereafter, the ileostomy was closed.

Conclusion
We treated Seminal vesicle-rectal fistula due to anastomotic leakage after Lap-LAR for rectal cancer.