The effect of contralateral kidney volume on renal function after radical nephroureterectomy: Implications for eligibility for neoadjuvant chemotherapy for upper tract urothelial cancer.

PURPOSE: We investigated the effect of preoperative contralateral kidney (CK) volume on renal function after radical nephroureterectomy (RNU).

METHODS

We reviewed 630 patients who underwent RNU between September 1994 and December 2013. Of these 630 patients, 135 patients with advanced upper tract urothelial cancer were ultimately included. Preoperative CK volume was measured from computed tomography images of the venous phase using a specialized volumetric program. Glomerular filtration rate (GFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations and checked preoperatively, 7 days, 1, 3, and 12 months postoperatively.

RESULTS

The mean age at surgery was 62.1 (10.1) years and the mean CKD-EPI GFR was 73.8 (75.5) ml/min/1.73m2. After RNU, new-onset CKD was identified in 69 (51.1%) patients. On multivariate logistic regression analysis, high body mass index (95% CI: 1.08-1.51, P = 0.005), low preoperative CKD-EPI GFR (95% CI: 0.92-0.98, P = 0.037), and low CK volume (95% CI: 0.96-0.99, P<0.001) were associated with new-onset CKD at 1 month after RNU. There was a positive correlation between CK volume and CKD-EPI GFR at 1 month after RNU (Spearman ρ = 0.495, P<0.001). When stratified according to CK volume, CK volume less than 150ml was significantly associated with new-onset CKD after RNU (95% CI: 2.49-26.29, P = 0.001).

CONCLUSIONS

High body mass index, low preoperative CKD-EPI GFR, and low CK volume are significantly associated with new-onset CKD. Therefore, they could be used to identify patients eligible for neoadjuvant chemotherapy in upper tract urothelial cancer.