[Comparison on efficacy between fascia-oriented versus vascular-oriented lateral lymph node dissection in patients...

Objective: To compare the postoperative function, the short-term and long-term outcomes between fascia-oriented and vascular-oriented lateral lymph node dissection (LLND) in patients with rectal cancer. Methods: A retrospective cohort study was performed. Clinical data of patients who received total mesorectal excision (TME) with LLND at National Cancer Center, Cancer Hospital of Chinese Academy of Medical Science from January 2014 to December 2019 were retrospectively collected. Inclusion criteria were as follows: (1) rectal cancer was pathologically diagnosed, and the lower margin was below the peritoneal reflection. (2) resectable advanced rectal cancer with suspected lateral lymph node metastasis was evaluated based on rectal MRI assessment. (3) preoperative MRI showed lateral lymph node short diameter ≥5 mm and/or lymph node morphology (spike, blur, irregular) as well as heterogenous signal intensity. Lymph node shrinkage was less than 60% after receiving neoadjuvant therapy based on the reassessment of rectal MRI. (4) TME+LLND surgery was performed synchronously. Exclusion criteria were as follows: (1) previous history of pelvic surgery; (2) preoperative cystitis, urethritis, moderate and severe prostatic hyperplasia and other diseases resulting in abnormal urination function; (3) preoperative sexual dysfunction or loss of function; (4) patients receiving LLND due to lateral recurrence after TME; (5) distant metastasis of the tumor at initial diagnosis; (6) Incomplete collection of clinical data. A total of 73 consecutive patients were enrolled in this study. Based on the surgical approaches in performing LLND, patients were divided into fascia-oriented group (n=30) and vascular-oriented group (n=43). There were no significant differences in baseline data between the two groups (all P>0.05). The main outcome indicators of this study were the incidence of postoperative urinary and male sexual dysfunction, the efficacy, the number of lateral lymph nodes harvested and the detection rate of positive lymph nodes. Overall survival (OS) rates and progression free survival (PFS) rates were calculated by the Kaplan-Meier method and compared by log-rank test. Results: All patients in both groups completed surgery successfully. There were no significant differences in operation time, intraoperative blood loss, postoperative complications, and the length of hospital stay between the two groups (all P>0.05). In the whole group, the incidence of postoperative urinary dysfunction and male sexual dysfunction was 43.8% (32/73) and 62.5% (25/40), respectively. The median number of lateral lymph nodes harvested was 8.0(4.0,11.0) with a positive rate of 20.5%(15/73). Compared to the vascular-oriented group, the fascia-oriented group demonstrated a decreased rate of urinary dysfunction [26.7% (8/30) vs. 55.8% (24/43), χ(2)=6.098, P=0.014], lower rate of sexual dysfunction in males [6/15 vs. 76% (19/25), χ(2)=5.184, P=0.023], more harvested lateral lymph nodes [M (P25, P75): 9.5 (6.8, 15.3) vs. 6.0 (3.0, 9.0), Z=-2.849, P=0.004]. There was no significant difference in the positvie rate of lateral lymph nodes between the two groups [20% (6/30) versus 20.9% (9/43), χ(2)=0.009, P=0.923]. Three(4.1%) patients were lost during a median follow-up of 34 (1-66) months. The 3-year PFS and OS of the whole cohort were 69.5% and 88.3%, respectively. No significant difference in 3-year PFS rates (79.6% vs. 62.0%, P=0.172) and 3-year OS rates (91.2% vs. 85.9%, P=0.333) were observed between the fascia-oriented group and the vascular-oriented group (both P>0.05). Conclusion: Fascia-oriented LLND is associated with lower risk of postoperative urinary and male sexual dysfunction in patients with rectal carcinoma, and harvest of more lymph nodes, but no significant advantage in long-term survival.