Objective To investigate the clinical value of fascia orientated laparoscopic lateral lymph node dissection (LLND) in radical excision for advanced low rectal cancer.

Methods The retrospective and descriptive study was conducted. The clinicopathological data of 100 patients with advanced low rectal cancer who were admitted to Peking University First Hospital from January 2013 to August 2021 were collected. There were 69 males and 31 females, aged 58(range, 32‒85)years. Patients underwent laparoscopic total mesorectal excision and fascia oriented LLND. Observation indicators: (1) surgical situations; (2) postoperative situations; (3) results of histopathological exa-mination; (4) follow‑up. Follow‑up was conducted by telephone interview, outpatient examination and medical records review to detect survival, disease progression, tumor recurrence and metastasis of patients up to August 2021. Survival time was from the surgery date to death or the last follow‑up time of patients. Measurement data were represented as M(range). Count data were represented as absolute numbers. Kaplan-Meier method was used to draw survival curves and calculate survival rates.

Results (1) Surgical situations. Of the 100 patients, 44 cases underwent neoadjuvant therapy and 56 cases didn′t receive preoperative therapy. Of the 100 patients with laparoscopic radical excision for advanced low rectal cancer, 60 cases underwent low anterior resection of rectal cancer including 49 cases with unilateral LLND and 11 cases with bilateral LLND,20 cases underwent abdomin-operineal resection for rectal cancer including 16 cases with unilateral LLND and 4 cases with bilateral LLND, 12 cases underwent total pelvic exenteration including 6 cases with unilateral LLND and 6 cases with bilateral LLND, 5 cases underwent Hartmann surgery including 3 cases with unilateral LLND and 2 cases with bilateral LLND, 3 cases underwent posterior pelvic exenteration including 2 cases with unilateral LLND and 1 case with bilateral LLND. The operation time and volume of intraoperative blood loss were 258(range,200‒325)minutes and 100(range, 50‒200)mL. There were 19 patients with low anterior resection of rectal cancer and protective ileostomy simultaneously. Three patients encountered intraoperative lymph node invasion of the obturator nerve, causing injury of the nerve at dissection. Of the 100 patients, 12 cases with total pelvic exenteration were dissected the ureterohypogastric nerve fascia and 88 cases were preserved the complete ureterohypogastric nerve fascia. (2) Postoperative situations. There was no perioperative death in the 100 patients. The time to postoperative catheter removal and duration of hospital stay of the 100 patients were 4(range, 3‒7)days and 11(range, 9‒15)days, respectively. There were 26 cases with postoperative complications. (3) Results of histopathological examination. The maximum tumor diameter was 4.5(range, 3.8‒5.9)cm. There were 21 patients with mass type of tumor pross and 79 cases with ulcerative type. There were 82 cases with high and moderate differentiation of tumor differentiation degree, 18 cases with low differentiation and undifferentiated adenocarcinoma (signet ring cell carcinoma). There were 14 cases in TNM stage Ⅰ, 38 cases in TNM stage Ⅱ, 48 cases in TNM stage Ⅲ. There were 16 cases in stage T0‒2 and 84 cases in stage T3‒4. There were 52 cases in stage N0 and 48 cases in stage N1‒2. The total number of lymph node dissected was 23(range, 18‒27)per person and the total number of unilateral LLND was 5(range, 3‒9)per person. There were 36 of 100 patients with positive lateral lymph nodes, including 14 cases with neoadjuvant therapy. (4) Follow‑up. Of the 100 patients, 97 cases were followed up for 21(range, 1‒69)months. The 2‑year overall survival rate was 81.6% and 2-year disease progression free survival rate was 70.6%. During the follow‑up, 4 of 97 patients had presacral tumor recurrence and 1 case had tumor recurrence in the LLND region. There were 11 cases with liver metastasis, 5 cases with bone metastasis, 2 cases with the contralateral lymph node metastasis of unilateral LLND, 2 cases with paraaortic lymph node metastasis, 2 cases with transcoelomic spread. Of the 97 patients who were followed up, 76 cases survived with free disease, 4 cases survived with tumor, 15 cases died of tumor and 2 cases died of other diseases.

Conclusion The fascia orientated laparoscopic LLND is safe and feasible in radical excision for advanced low rectal cancer.