Risk factors of long-term postoperative renal function after partial nephrectomy in a solitary kidney

The effect of warm ischemia time (WIT) on long-term renal function after partial nephrectomy remains controversial. In this retrospectively cohort study, 75 solitary kidney patients were included and the effects of warm ischemia time, preoperative renal function and resected normal parenchyma volume on long-term renal function were evaluated. Multivariable analysis showed that the preoperative renal function baseline was significantly associated with renal function 12 months postoperation (P=0.01), adjusting for age and comorbidities factors. Meanwhile, perioperative acute renal failure (ARF) events significantly affected postoperative renal function at postoperative time points of 12 months (P=0.001) and 60 months (P=0.03), as well as renal function change at postoperative 12 months (P<0.01). Warm ischemia time and resected normal parenchyma volume were not risk factors for long-term postoperative renal function, while the latter was significantly associated with renal function change (P=0.03 at 12 months, P<0.01 at 36 and 60 months). In conclusion, the quality of preoperative kidney primarily determines long-term postoperative renal function, while the quantity of preserved functional parenchyma volume was the main determinant for long-term kidney recovery. ARF was an independent risk factor while WIT was indirectly associated with postoperative renal function by causing perioperative ARF.