Background: The addition of lateral pelvic lymph node dissection (LPLND) in rectal cancer surgery has been reported to increase the incidence of post-operative urinary retention. Here, we assessed the predictive factors and long-term outcomes of urinary retention following laparoscopic LPLND (L-LPLND) with total mesorectal excision (TME) for advanced lower rectal cancer. Methods: This retrospective single-institutional study reviewed post-operative urinary retention in 71 patients with lower rectal cancer who underwent L-LPLND with TME. Patients with preoperative urinary dysfunction or who underwent unilateral LPLND were excluded. Detailed information regarding patient clinicopathologic characteristics, post-void residual urine volume, and the presence or absence of urinary retention over time was collected from clinical and histopathologic reports and telephone surveys. Urinary retention was defined as residual urine > 100 mL and the need for further treatment. Results: Post-operative urinary retention was observed in 25/71 patients (35.2%). Multivariate analysis revealed that blood loss ≥ 400 mL [odds ratio (OR) 4.52; 95% confidence interval (CI) 1.24–16.43; p = 0.018] and inferior vesical artery (IVA) resection (OR 8.28; 95% CI 2.46–27.81; p < 0.001) were independently correlated with the incidence of urinary retention. Furthermore, bilateral IVA resection caused urinary retention in more patients than unilateral IVA resection (88.9% vs 47.1%, respectively; p = 0.049). Although urinary retention associated with unilateral IVA resection improved relatively quickly, urinary retention associated with bilateral IVA resection tended to persist over 1 year. Conclusion: We identified the predictive factors of urinary retention following L-LPLND with TME, including increased blood loss (≥ 400 mL) and IVA resection. Urinary retention associated with unilateral IVA resection improved relatively quickly. L-LPLND with unilateral IVA resection is a feasible and safe procedure to improve oncological curability. However, if oncological curability is guaranteed, bilateral IVA resection should be avoided to prevent irreversible urinary retention.
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