Postoperative urinary dysfunction following lateral lymph node dissection for rectal cancer via minimally invasive surgery.

Background: Lateral lymph node dissection (LLND) for locally advanced rectal cancer (LARC) is performed widely since it reduces local recurrence. However, there are some disadvantages to LLND, including technical difficulties and association with postoperative urinary dysfunction. Procedures for LARC have also become more minimally invasive: laparoscopic surgery (LS) has become more common, and use of robot-assisted LS (RALS) is increasing. The purpose of this study is to assess differences in postoperative urinary dysfunction after LLND for LARC between LS and RALS, and to identify risk factors for postoperative urinary dysfunction.

Methods: The subjects were 100 patients with LARC (≥ cT3) with the inferior border of the tumor reaching the peritoneal reflection who underwent LS or RALS with LLND between 2009 and 2023 at Juntendo University Hospital. After LLND, the urinary catheter was usually removed on or before postoperative day 5. The duration of urinary catheterization (DUC) was used to evaluate postoperative urinary dysfunction. The standard (S) and long-term (L) groups were defined as cases with urinary catheter removal at ≤ 5 and > 5 days, respectively. DUC was examined for LS vs. RALS and clinicopathological factors were identified that adversely affect DUC.

Results: Of the 100 subjects, 72 underwent LS and 28 received RALS. LLND was bilateral in 65 cases and unilateral in 35 cases. The median DUC was 5 days, with 74 cases in group S and 26 in group L. The most frequent postoperative complication (Clavien-Dindo Grade 2 or higher) was urinary dysfunction, followed by ileus and surgical site infection (SSI), and none differed by procedure (LS vs. RALS). Univariate analysis showed significant differences in LLND laterality (p = 0.02) and SSI (p = 0.04) between groups S and L. In multivariate analysis, bilateral LLND (p < 0.01, HR 7.37) and SSI (p = 0.01, HR 15.36) were independent factors that worsened DUC.

Conclusions: There was no difference in urinary dysfunction after LLND between LS and RALS. Bilateral LLND and SSI were risk factors for lengthening DUC. Compared to bilateral LLND, unilateral LLND can reduce urinary dysfunction; therefore, selective LLND, which is overwhelmingly unilateral LLND, and prevention of perioperative SSI may be important for maintenance of urinary function.