Transanal Pull‐Through Rectal Amputation for Treatment of Colorectal Carcinoma in 11 Dogs

Objective— To evaluate outcome after transanal rectal pull-through amputation of single colorectal adenocarcinoma and in situ carcinoma (Tis) in dogs. Study Design— Retrospective case series. Animals— Dogs (n=11) with colorectal cancer. Methods— Full-thickness colorectal amputation by either simple transanal (7 dogs) or combined abdominal–transanal (4) pull-through technique. Results— Adenocarcinoma (8) and Tis (2) were removed with 3–6 cm of grossly normal tissue, cranial and caudal to the tumor, or in 1 Tis with 2 cm grossly normal tissue, cranial and caudal. Two dogs that had a combined abdominal–transanal approach died within 4 days. In the other dogs, postoperative complications included short-term tenesmus (6 dogs), rectal bleeding (11), rectal stricture (3), and long-term fecal incontinence (1). Postoperative recurrence and metastatic rates for adenocarcinoma were 18.2% and 0%, respectively. Median disease-free interval and survival time were not reached. Mean disease-free and overall survival times were 44.3 and 44.6 months (range, 0–75 months), respectively. Conclusion— En bloc excision of colorectal Tis and adenocarcinoma may be followed by a long survival. Complications of the transanal approach are usually moderate and self-limiting, but complications are more common and severe when more extensive resections are performed through a combined abdominal–transanal approach. Clinical Relevance— Transanal rectal pull-through amputation is suitable for en bloc resection of colorectal neoplasia. A combined abdominal–transanal approach should be reserved for tumors extending from the mid-cranial region of the rectum to the descending colon.