[Surgical key points of precision functional sphincter-preserving surgery]

The principle of sphincter-preserving surgery is to preserve the anal sphincter function under the premise of radical resection. Due to low position of rectal tumor, conventional laparoscopic surgery has difficulties in operating in the deep and narrow pelvis, which may lead to inaccurate tissue dissociation, imprecise positioning of tumor edge, excessive stretch of the anal sphincter complex, and excessive removal of distal rectal mucosa. Moreover, pain from abdominal auxiliary incision has an unavoidable side effect for postoperative recovery. With the help of the Liu's transanal microsurgery system, precision functional sphincter-preserving surgery (PPS) can be successfully performed. PPS tries to preserve left colonic artery and pelvic autonomic nerve in the transabdominal operation. In the part of transanal surgery, measurement, localization and resection of the lower edge of the tumor are conducted under a clear and open visual field with the transparent screw anal dilator. After the rectum is cut off, the specimen is taken out through the anus to avoid abdominal incision. Inserting the intestinal supporter to support the bowel stump, full thickness of bowel stump is then sutured with anal canal by vertical mattress suture. Special transanal tube is placed afterwards without routine prophylactic stoma. PPS can achieve precise tumor resection and sphincter preservation simultaneously.