The technique the investigators propose to perform colorectal and colo-anal anastomosis in patients underwent low and ultra-low anterior resection for rectal cancer could potentially reduce the anastomotic leakage rate by better trans-anal introduction of the circular stapler, elimination of the previous suture lines and dog ears, combined with direct inspection of the anastomosis, easy performance of trans-anal air leak tests and eventually direct repair of any small anastomotic defects. Another important point in cancer surgery is the easily identification of the distal margin. In fact, this technique is simple to perform, reproducible and safe in terms of complications.

-Study design Subjects for this study were prospectively enrolled between January 2013 and January 2016 in the participating centers.

All patients signed written informed consent including the possibility of future publication according to the Italian bioethics laws. Institutional Review Board (IRB) approval has been obtained from the local Ethical Committee of each center in compliance with the Principals of Helsinki Declaration.

-Preoperative assessment and preparation All cases were discussed individually on colorectal multidisciplinary meeting with standard preoperative staging for rectal cancer including; colonoscopy with biopsy, CT chest, and abdomen, MRI pelvis and/or endo-rectal ultrasound. All patients were evaluated preoperative by expert anesthesiologists for individual co-morbidity with classification according to the ASA score.

The day before surgery mechanical bowel preparation with 4 liters of PEG (PolyEthilene Glycol) was administered together with liquid diet. An adequate thromboembolic prophylaxis with low molecular weight heparin was given the evening before the surgery. Antibiotic prophylaxis with second generation cephalosporin was administered at induction of anesthesia.

-Surgical technique The low or ultra-low anterior resection with total mesorectal excision (TME) were performed, either open, laparoscopic, robotic. Just before rectal division, the circular anal dilator (CAD) device was introduced into the anal canal and fixed by four 0-silk suture to the perianal skin apply at the 4 cardinal's points. The rectal inspection was carried out by the Purse Suture Anoscope (PSA) to correctly identify the proximal and distal extension of the tumor. After that the rectum was divided by linear or curved stapler under CAD direct inspection.

Four 2-0 prolene sutures were trans-anally placed on the rectal stump; 2 of them at the extremities of the suture line (left and right) and the other two 1 cm medially to each of the previous two sutures. Circular stapler was introduced through the CAD (29 or 33 mm KOL stapler, Touchstone International Medical Science Co., Ltd.), the 4 tails of the prolene stitches were introduced through the stapler channels (2 in the left and 2 in the right side of the instrument) and gently pulled in order to obtain a gradual and homogeneous traction of the tissue. After elimination of both previous suture lines and dog ears, then the stapler was fired.

The rectal anastomosis was carefully inspected trans-anally then tested intraoperatively by air leak test through trans-anal air insufflation with the pelvis immersed with physiological saline to detect bubbles, and competence of donuts. If the anastomosis was considered safe the need for protective stoma was left to discretion of operating surgeon.

CAD may be removed at the end of the surgery, or left in place for 3-4 days postoperative to provide a safe and fast access for anastomosis inspection as well to reduce the endo-luminal pressure.

• Postoperative care The postoperative care concise with the standard care for patients who underwent low or ultra-low rectal resection, thromboembolic prophylaxis continued inform of single low molecular weight heparin 5000 IU 8 hours postoperative or according to the risk status of patients. Antibiotics for 3 days postoperative inform of 1 gm 2nd generation cephalosporin. We encourage fast tract surgery inform early feeding and mobilization as described below;

  • 1st POD: removal of the urinary catheter, start mobilization,
  • 2nd POD: start oral fluid,
  • 3rd-4th POD: start semi-solid then solid feeling,
  • 5-6th POD: discharge home (after performing contrast enema or colonoscopy).

• Definition of anastomotic leak There is no constant definition for anastomotic leak, but we adapted the criteria recently published by Adams and Papagrigoriadis [8]; feculent material from the drain or the wound, extravasation of dye on contrast enema, anastomotic defect visualized by colonoscopy, or the presence of peri-anastomotic air or fluid visualized by CT scan.

• Patient's fellow-up Patients were followed-up at the outpatient's clinics at one week, two weeks, and at one month postoperative. A further follow-up occurred at time of stoma reversal in patients with diversion in form of colonoscopy to access anastomotic integrity and preoperative anesthetic fitness as usual. Follow-up was continued at twelve months' postoperative by aid of complete colonoscopy.

• Variables studied and statistical analysis Basic demographic data were recorded including age and sex of patients as well as detailed information on BMI, ASA, stage and distance of the tumor from anal verge, neo-adjuvant chemotherapy, type of surgical approach (open, laparoscopic and robotic procedure), duration of the operation, postoperative hospital stay, postoperative morbidity and mortality. Data were analyzed using excel and SPSS (Statistical Package for Social Science) version 21 programs under Microsoft Windows. Quantitative data were expressed as mean ± SD when possible.

Inclusion Criteria:

• Patients undergoing low or ultra-low anterior resection for biopsy proven primary rectal cancer

Exclusion Criteria:

• Patients younger than 18 years old,
• pregnant,
• recurrent disease,
• cancer less than 4 cm from the anal verge,
• abdomeno-perineal resection,
• emergency surgery