[Transanal conformal resection for super low rectal cancer].

Intersphincteric resection(ISR) is a valuable anus-preserving operation that avoids the need for permanent stoma in patients with super low rectal cancer. Recently, with the application and promotion of ISR, the rate of anus-preservation has been greatly elevated, however, some patients following ISR had poor anal function. Based on the knowledge of anal canal anatomical features for better anal function, we propose conformal sphincter-preserving operation (CSPO) for super low rectal cancer, which is a new integrated anus-preservation procedure with total mesorectal excision (TME), coloanal anastomosis, pull through resection, anal canal dissection, local resection and natural orifice transluminal endoscopic surgery technology. CSPO includes pull through conformal resection (PTCR) and transanal conformal resection (TaCR). This article focuses on the problems about TaCR for very low rectal cancer and introduces TaCR combined with our practical experience. The indications for the TaCR operation should be according to the conventional laparoscopic surgery. In addition, the TaCR operation has its special indications: the tumor location is within 2 cm of the dental line; the tumor is well differentiation (moderately to well differentiation); the diameter of the tumor is not more than 3 cm or no more than the 1/3 circle of intestinal wall; and the depth of invasion is T1-T2. Patients with a clinical complete remission after neoadjuvant radiochemotherapy can receive TaCR. The laparoscopic five hole method is used to carry out the abdominal operation with TME technique. It is unnecessary to dissection intersphincter space. The incisional line is made according to the tumor location and shape to preserve the opposite normal rectal wall, internal sphincter and dentate line as more as possible via transanal resection. After closing the rectal stump by interrupted sutures, a circular stapler or hand suture is use to perform the anastomosis as far from the dentate line as possible. Protective loop ileostomy is performed. Postoperative complications, including anastomotic leakage, abdominal infection, and anastomotic bleeding, should be remembered. If there is any signs of these complications, intervention should be done as soon as possible.