Study procedures and data collection
tumor, intraoperative bowel perfusion, Colorectal Functional Outcome) [, venous thrombosis
TUMOR, POSTOPERATIVE COMPLICATIONS, EVENTS, APPENDIX, VENOUS THROMBOSIS
Preoperative bowel preparation and venous thrombosis prophylaxis were administered based on sites’ local protocols. Enhanced recovery protocols were used when possible with intraoperative anesthetic regimens including local, regional or intrathecal anesthesia. Surgeons were required to perform all taTME procedures with a 2-team approach using sequential or simultaneous abdominal and transanal dissection, and to video record all transanal procedures (Protocol, Online Appendix 1). Abdominal minimally invasive approach, distal vs proximal extent of abdominal vs transanal, and extent of anterior vs posterior TME dissection was left up to surgeons’ preferences. Typically, the anterior TME dissection was carried down to the anterior peritoneal reflection or mid-vagina/prostate, while posterior TME dissection is typically extended to the S1 or S2 level. For transanal procedures, the rectal lumen was occluded below the tumor with a single or double purse-string suture with air-tight closure prior to initiating taTME dissection. Alternatively, purse-string closure followed initial mucosectomy or partial intersphincteric resection, when performed. The choice of transanal endoscopic platform, splenic flexure mobilization, specimen extraction site, intraoperative bowel perfusion assessment by fluorescence angiography, anastomotic configuration, fecal diversion and pelvic drain placement were left to the surgeon’s preference and recorded. Gross specimens were photographed, inked and processed according to standard TME protocols [Patient and tumor characteristics including demographics, comorbidities, tumor height, radiologic staging, neoadjuvant treatment received, and time interval between end of treatment and surgery were collected. Procedural details, intraoperative events, and length of hospital stay were recorded, in addition to postoperative complications reported during follow-up clinical visits, which were graded using Clavien–Dindo classification [Pathological assessment of specimens was collected from synoptic reports and included grade of completeness of the mesorectum, TNM stage, and assessment of circumferential radial margins, and proximal and distal margins [Urologic, sexual, and defecatory function was assessed at least once preoperatively and at 2 postoperative time points, 3–4 months and 9–12 months post-stoma reversal. Validated questionnaires were used, including COREFO (Colorectal Functional Outcome) [