L’ischémie a un impact limité sur la fonction rénale après néphrectomie partielle sur rein unique chez les patients sans insuffisance rénale préopératoire

[Partial nephrectomy on solitary kidney: Renal function outcome and predictive factors of impairment]

OBJECTIVES

To assess the postoperative functional outcome of PN in solitary kidney and define some predictive factors of renal change.

MATERIAL AND METHODS

A monocentric series of 45 partial nephrectomies on solitary kidneys, performed between 1988 and 2014, was retrospectively analyzed. Pre-, per- and postoperative clinicopathological data were collected in the UroCCR database. The evolution of early, medium and long-term postoperative Glomerular Filtration Rate (GFR) was evaluated. Predictive factors of GFR decline and hemodialysis were assessed in multivariate analysis.

RESULTS

Mean age was 61 years old (±10.8). Mean preoperative GFR and tumor size were respectively 59.6 mL/min (±18.7) and 3.9 cm (±2.6). Vascular clamping was performed in 41 cases (91%). Median time of warm ischemia was 20 minutes (2-60). Mean follow-up was 66 months (±47). Mean GFR at day 5, 1 month and last follow-up were respectively 46.4 mL/min, 50.3 mL/min and 53.1 mL/min. At day 5 and at last follow-up, a GFR decrease ≥ 20% was found in 20 patients (44.4%) and in 16 patients (35.5%), respectively. Five patients (11%) required definitive hemodialysis (HD) at last follow-up. At day 5, tumor size>4 cm (0.006) and operative time (P=0.003) were independent predictive factors of GFR decline. At 1 year, RENAL ns ≥ 10 was the only independent predictive factor of GFR alteration (P=0.0007). Preoperative GFR was significantly associated with final hemodialysis (P=0.023).

CONCLUSION

Partial nephrectomy allows most of the patients presenting with renal cell carcinoma on solitary kidney to be free of hemodialysis. Tumor complexity, tumor size and preoperative GFR seems to play a determinant role on postoperative functional outcome. These non-modifiable predictive factors should be recognized and taken into account to better select patients with high risk of postoperative renal failure.

LEVEL OF EVIDENCE

5.