PURPOSE

Urinary dysfunction (UD) is still a major complication after lower rectal cancer (LRC) surgery. Untreated UD is an independent risk factor for renal dysfunction due to repeated urinary reflux and urinary tract infections. However, the relationship between postoperative UD and renal function following LRC surgery remains unclear. In this study, we investigated the impact of UD on renal function post-surgery.

METHODS

We retrospectively evaluated 83 patients with LRC who underwent curative resection at our tertiary referral center between April 2015 and December 2018. UD was diagnosed as a post-void residual urine volume ≥ 50 mL using uroflowmetry tests after discharge. We compared the estimated glomerular filtration rate (eGFR) and the incidence of chronic kidney disease (CKD)-defined as an eGFR < 60 mL/min/1.73 m-at 3 years after LRC surgery between the UD and non-UD groups. Patient selection was based on the criteria that excluded those with a history of urogenital interventions or incomplete postoperative follow-up. Statistical analysis used the Mann-Whitney U test for continuous variables, Fisher's test for categorical data, and multivariate logistic regression to adjust for potential confounders.

RESULTS

Of the 83 patients, 21 (25%) had UD. Patients with UD were older, underwent more extensive surgery, and had significantly longer operation times than those without UD. Within 3 years post-surgery, the UD group experienced a higher incidence of urinary tract complications and CKD, with a notable decrease in eGFR. Additionally, a history of hypertension and UD were identified as independent risk factors for CKD at 3 years post-surgery.

CONCLUSIONS

Patients with UD showed a significant decrease in eGFR and were more likely to progress to CKD at 3 years after LRC surgery. These findings indicated that postoperative UD might adversely affect renal function in patients with LRC.