[Comparison between laparoscopic-assisted natural orifice specimen extraction surgery and conventional laparoscopic surgery for left colorectal cancer: 5-year follow-up results of a randomized controlled study].

To evaluate the long-term efficacy of laparoscopic-assisted natural orifice specimen extraction surgery (NOSES) colectomy using Cai tube for treating left-sided colorectal cancer. This was a randomized controlled trial. Inclusion criteria were as follows: preoperative pathological diagnosis of left-sided colorectal adenocarcinoma (rectal, sigmoid colon, descending colon, or left transverse colon cancer with the caudad margin ≥8 cm from the anal margin); preoperative abdominal and pelvic computed tomography (or magnetic resonance imaging) showing maximum tumor diameter <4.5 cm; and BMI <30 kg/m. Patients with synchronous multiple primary cancers or recurrent cancers, a history of neoadjuvant chemoradiotherapy, preoperative evidence of significant local infiltration, distant metastasis, or complications such as intestinal obstruction and intestinal perforation, or who were not otherwise considered suitable for laparoscopic surgery were excluded. A random number table was used to randomize sequential patients to NOSES surgery using Cai tube (non-assisted incision anal sleeve: patent number ZL201410168748.2) (NOSES group) or traditional laparoscopic-assisted surgery (CLS group). Relevant clinical data of the two groups of patients were analyzed, the main outcomes being disease-free survival, overall survival, overall recurrence rate, and local recurrence rate 5 years after surgery. Patients in both study groups completed the surgery successfully with no requirement for additional surgery. After mean 70 (7-83) months postoperative follow-up, the 5-year overall postoperative survival in the NOSES and CLS groups was 90.0% and 83.3%, respectively (=0.455); disease free survival was 90.0% and 83.3%, respectively (=0.455); overall recurrence rate 6.6% and 10.0%, respectively (=0.625); and local recurrence rate both were 3.3% (=0.990), respectively. None of these differences was statistically significant. NOSES and CLS have similar long-term efficacy, and NOSES deserves to be used in clinical practice.