Measured glomerular filtration rate (GFR) significantly and rapidly decreases after radical cystectomy for bladder cancer.

Precise determination of glomerular filtration rate (GFR) is essential for the management of patients with muscle-invasive bladder cancer (MIBC). We aim to describe the early evolution of measured GFR (mGFR) after radical cystectomy and urinary diversion (RCUD) and to identify risk factors for GFR decline. GFR measurement using 51Cr-EDTA continuous infusion, estimated GFR (eGFR) from five published equations and renal scintigraphy with split renal function determination were performed before and 6 months after RCUD. Chronic Kidney Disease (mGFR < 60 mL/min/1.73 m2) and GFR stages were defined according to the KDIGO guidelines using mGFR. Twenty-seven patients (men 85%, median age 65, IQR 59; 68 years) were included. A total of 20 (74%) patients experienced significant mGFR decline at 6 months postoperatively. Median mGFR decreased from 84.1 pre-operatively (IQR 65.3; 97.2) to 69.9 mL/min/1.73 m2 (IQR 55.0; 77.9) 6 months after surgery (p < 0.001). Thirteen (48%) patients had a progression to a worse GFR stage. Of the 22 patients without pre-operative CKD, 5 (23%) developed post-operative CKD. Diabetes mellitus was more frequent in patients in the highest tertile of relative mGFR decline (44% vs. 11%, p = 0.02) and platinum-based adjuvant chemotherapy tended to be more frequently used in these patients (44% vs. 17%, p = 0.06). Importantly, pre-operative weight was independently and negatively associated with post-operative mGFR and with mGFR slope in multivariable analyses. In this prospective series, we demonstrated that early and significant mGFR decline occurred after RCUD and perioperative platinum-based chemotherapy, especially in patients with diabetes mellitus and overweight.

Association of mGFR of the Remaining Kidney Divided by Its Volume before Donation with Functional Gain in mGFR among Living Kidney Donors.

BACKGROUND AND OBJECTIVES: The predictors of long-term renal function in living kidney donors are currently discussed. Our objectives were to describe the predictors of functional gain of the remaining kidney after kidney donation. We hypothesized that GFR of the remaining kidney divided by volume of this kidney (rk-GFR/vol) would reflect the density of functional nephrons and be inversely associated with functional gain of the remaining kidney. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted a prospective monocentric study including 63 living donors (26 men; 50.3±11.8 years old) who had been evaluated for (51)Cr-EDTA and measured GFR, split renal function by scintigraphy before donation (between 2004 and 2009), and measured GFR at 5.7±0.5 years after donation. For 52 donors, volume of the remaining kidney (measured and estimated with the ellipsoid formula using renal computed tomography scannography) was determined before donation. We tested our hypothesis in an external validation cohort of 39 living donors (13 men; 51.0±9.4 years old) from another single center during the same time period. RESULTS: For the main cohort, the mean measured GFR was 97.6±13.0 ml/min per 1.73 m(2) before donation and 63.8±9.4 ml/min per 1.73 m(2) at 5 years. Functional gain averaged 16.2±7.2 ml/min per 1.73 m(2) (+35.3%±16.7%). Multivariate analysis showed that age, body mass index, and rk-GFR/vol at donation were negatively correlated with functional gain and had strong predictive power of the 5-year functional gain (adjusted 5-year functional gain for age: -0.4 [95% confidence interval (95% CI), -0.5 to -0.1]; body mass index: -0.3 [95% CI, -0.6 to -0.1]; rk-GFR/vol: -55.1 [95% CI, -92.3 to -17.9]). We tested this model in the external validation cohort (adjusted 5-year functional gain for age: -0.1 [95% CI, -0.5 to 0.3]; body mass index: -0.9 [95% CI, -1.8 to -0.1]; rk-GFR/vol: -97.6 [95% CI, -137.5 to -57.6]) and confirmed that rk-GFR/vol was inversely associated with 5-year functional gain. CONCLUSIONS: For given age and body mass index, the long-term functional gain of the remaining kidney is inversely associated with the new variable rk-GFR/vol at donation.