Study design
tumor, Tumor
TUMOR, TUMOR, ADVERSE EVENTS, RECTAL CANCER, SECONDARY, RECTAL CANCER, ADENOCARCINOMA, PATHOLOGY, APPENDIX, COMPLICATIONS
This is a phase II prospective multicenter trial conducted across 11 experienced taTME centers in the US and Canada. The primary endpoint was the rate of complete and near-complete mesorectal excision achieved with taTME, and secondary endpoints included detailed pathology assessment, 30 and 90-day complications, functional outcomes post-stoma reversal, and 3-year oncologic outcomes. The protocol was approved at each participating site IRB, and written informed consent was obtained from all study participants prior to enrollment (Protocol, Online Appendix 1). The trial was registered on clinicaltrial.gov (NCT03144765). The manuscript conforms to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines [Surgeon eligibility requirements included performance of ≥ 20 sphincter-preserving low anterior resections (LAR) including ≥ 5 taTME cases in the preceding 12 months and ≥ 20 transanal endoscopic resections by transanal surgeons in the preceding 24 months. Participating surgeons had been performing taTME procedures for a minimum of 3 years, and were required to submit recent unedited transanal video recordings of 2 cases, including one in a male patient, along with pathology reports and photographs of gross TME specimens to confirm technical proficiency. Study sites were required to follow National Accreditation Program in Rectal Cancer (NAPRC) standards with respect to staging and treatment protocols, multidisciplinary tumor board (MDT) review and consensus treatment planning of all rectal cancer patients [Patients > 18 years old, with clinically staged I–III biopsy-confirmed adenocarcinoma, located ≤ 10 cm from the anal verge, who were candidates for minimally invasive curative sphincter-preserving low anterior resection with tumor-specific (TSME) or TME, were screened for study enrollment. Tumor height and relationship to the anal sphincters was based on digital rectal exam (DRE), and/or rigid proctosigmoidoscopy, and confirmed on staging MRI and operative reports. Staging was completed with CT scans of the chest, abdomen and pelvis and rectal cancer protocol pelvic MRI. Neoadjuvant and adjuvant treatment protocols were based on MDT consensus recommendations and included short-course radiotherapy (SCRT), long-course chemoradiotherapy (CRT), total neoadjuvant therapy (TNT) or chemotherapy only. Chemotherapy regimens included Capecitabine, 5-FU, FOLFOX, or Capecitabine in combination with Oxaliplatin. Oncologic surveillance scheduled followed NCCN guidelines. Clinical assessment was performed at 2 and 4–6 weeks, 5–7 months and 11–13 months postoperative visits in order to collect adverse events. Patients completed baseline preoperative functional questionnaires at least once prior to surgery, and at two postoperative time points post-stoma reversal, when applicable.Enrollment occurred either prior to neoadjuvant treatment or prior to taTME (Fig. Patient enrollment flowchart. NT, neoadjuvant treatment; mrT4/mrCRM + , predicted T4 or positive circumferential margin on staging pelvic MRI; 