Objective To investigate the application value of transanal endoscopic partial intersphincteric resection for ultra‑low rectal cancer.

Methods The retrospective and descriptive study was conducted. The clinicopathological data of 9 ultra‑low rectal cancer patients undergoing transanal endoscopic partial intersphincteric resection at the First Affiliated Hospital of Xiamen University from December 2017 to August 2020 were collected. There were 8 males and 1 female, aged from 39 to 62 years, with a median age of 58 years. Observation indicators: (1) surgical and postoperative situations; (2) postoperative pathological examination; (3) follow‑up. Follow‑up was conducted using outpatient examination and telephone interview to detect postoperative tumor local recurrence and distant metastasis, survival of patients, ileostomy closure, anus function at 3 months after ileostomy closure, male urinary and sexual function and female sexual function at 6 months after rectal surgery. The follow‑up was up to February 2021. Measurement data with normal distribution were represented as Mean±SD, and measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers.

Results (1)Surgical and postoperative situations: all 9 patients underwent surgery successfully, without conversion to open surgery. Seven of the 9 patients underwent transanal endoscopic partial intersphincteric resection and the rest of 2 patients with tumor close to the dentate line underwent transanal endoscopic modified partial intersphincteric resection. The operation time and volume of intraoperative blood loss of 9 patients were (267±48)minutes and 50 mL(range, 30‒60 mL), respectively. Five of the 9 patients underwent transanal specimen extraction, and 4 patients underwent specimen extraction by an abdominal incision. All 9 patients underwent transanal hand‑sewn coloanal anastomosis and protective ileostomy, and two pelvic drainage tubes were indwelled. Transanal drainage tube was placed after anastomosis in 3 of 9 patients. Three cases had intraoperative adverse events and there were no intraoperative adverse event reported in the remaining 6 cases. The time to postoperative initial stoma exhausting and time to postoperative first semi‑liquid food intake of 9 patients were 3 days(range, 2‒4 days) and 5 days(range, 4‒7 days), respectively. One case had Clavien‑Dindo grade Ⅰ complication and 2 cases had Clavien‑Dindo grade Ⅱ complication during postoperative 30 days and the rest of 6 cases had no postoperative complication. No anastomotic stricture, hemorrhage or urinary retention occurred in 9 patients. The duration of postoperative hospital stay and cost of hospitalization of 9 patients were 11 days(range, 9‒23 days) and (6.8±1.3)×10⁴ yuan, respectively. (2) Postoperative pathological examination: the diameter of tumor, the distance of distal resection margin, the number of lymph node dissected and the number of positive lymph node of 9 patients were (3.2±1.4)cm, 0.6 cm(range, 0.5‒1.5 cm), 17±7 and 0(range, 0‒7), respectively. The tumor histopathological type was adenocarcinoma with negative tumor nodule and nerve infiltration in all 9 patients. Only 1 case of 9 patients was found vascular tumor thrombus. The surgical specimens of all 9 patients showed negative for distal and circumferential margins and complete mesorectum. Results of postoperative pathological TNM staging showed that of 6 cases with preoperative T1-T2 staging tumors, 3 cases were classified as pT2N0M0 stage, and 3 cases were classified as pT2N1M0 stage, pT2N2M0 stage or pT3N1M0 stage, respectively. Three cases with preoperative T3 staging tumors were classified as ypT0N0M0 stage, ypT2N0M0 stage or ypT3N0M0 stage, respectively. (3) Follow‑up: all 9 patients were followed up for 6 to 13 months, with a median follow‑up time of 9 months. No local recurrence, distant metastasis or tumor‑related death was found during follow‑up. Of the 9 patients, only 1 case did not receive stoma closure and undergo anus function assessment, and the rest of 8 cases underwent stoma closure. Results of postoperative anus function assessment showed 5 cases of accessibility, 2 cases of mild impairment and 1 case of severe impairment. Results of urogenital function assessment showed 6 cases of the 8 male patients of mild impairment, 1 case of moderate impairment and 1 case of severe impairment in micturition function, respectively, and 3 cases of accessibility, 2 cases of mild impairment and 3 cases of moderate impairment in sexual function, respectively. The female patient underwent accessibility of sexual function and the six‑item version of the female sexual function index was 25.

Conclusion Transanal endoscopic partial intersphincteric resection can be used for the treatment of ultra‑low rectal cancer.