466 Colo-Seminal Vesicle Fistula as a Complication of Low Anterior Resection

A fistula between the colon and seminal vesicles following low anterior resection is an uncommon post-operative complication. This report details the case of a 68-year-old patient diagnosed with locally advanced mid-low rectal cancer (T3N2M0). He underwent short-course radiotherapy and consolidation chemotherapy (RAPIDO), followed by laparoscopic low anterior resection. With a background of diabetes and a BMI of 36, and being registered blind, it was decided not to give him a defunctioning stoma. The immediate post-op period was uneventful; however, six weeks post-operatively, he returned with pneumaturia. A flexible cystoscopy ruled out bladder or urethral pathology. Further investigation, including CT and MRI, revealed a fistulous connection between the sigmoid colon and seminal vesicles. An anastomotic leak was suspected, and an initial flexible sigmoidoscopy was unable to identify this due to poor bowel preparation, prompting initial conservative management. However, a repeated flexible sigmoidoscopy eventually confirmed complete anastomotic dehiscence. Despite initially being clinically well, he eventually developed testicular swelling and elevated inflammatory markers, with CT suggestive of air tracking via the vas deferens and scrotal air. He underwent laparoscopic disconnection of the anastomosis, culminating in the formation of an end colostomy and perianal proctectomy with concurrent exploration of the left scrotum and bilateral ureteric stenting. Post-operatively, he spent several days in the ITU before being transferred to the wards. Over the next 25 days, the patient clinically improved and was eventually discharged symptom-free. The report captures the link between an anastomotic leak and a rare fistula formation between the colon and seminal vesicles after low anterior resection.