| ObjectiveTo investigate the factors influencing the prognosis of renal function in patients with renal tumor after nephron sparing surgery(NSS).The relative effects of parenchymal volume preserved and renal ischemia on functional outcomes after NSS were mainly studied.MethodsMedical records of 133 patients who underwent NSS in our hospital from December2016 to October 2019 were retrospectively analyzed.The patient’s age,gender,body mass index,history of diabetes,history of hypertension,maximum tumor diameter,R.E.N.A.L.score,surgical method,operative time,and warm ischemia time(WIT)were recorded.Blood creatinine value,affected renal glomerular filtration rate(GFR),healthy kidney GFR,total GFR,GFR preserving rate(the ratio of postoperative GFR to preoperative GFR),functioning parenchymal volume(FPV)of the affected renal,and FPV preserving rate of the affected renal(the ratio of postoperative FPV and preoperative FPV)were recorded before and 6 months after surgery.Paired sample t test was used to compare GFR and FPV before and after surgery.Spearman rank correlation analysis was adopted to evaluate the correlation between the study factors and GFR preserving rate of the affected renal.Multivariate linear regression models were used to analyze independent predictors of renal function of the affected renal and recovery from ischemia,respectively.Results1.All operations were completed successfully,with a median operation time of 135min(110～165min)and mean WIT(24.67±5.42)min.Preoperative GFR of the affected renal was(48.46±11.42)ml/min/1.73m~2,and postoperative GFR of the affected renal was(35.53±7.63)ml/min/1.73m~2(P<0.001).The GFR preserving rate of the affected renal was(74.42±11.18)%.2.Spearman rank correlation analysis showed that there was a strong positive correlation between the FPV preserving rate of the affected renal and the GFR preserving rate of the affected renal(r=0.798,P<0.001),WIT was negatively correlated with the GFR preserving rate of the affected renal(r=﹣0.533,P<0.001).Multiple linear regression analysis showed that preoperative GFR of the affected renal(P=0.003),WIT(P<0.001)and the FPV preserving rate of the affected renal(P<0.001)were independent predictors of the GFR preserving rate of the affected renal.3.According to the ischemic time group,the median recovery from ischemia rates of ischemic time<25min group,25～30min group and≥30min group were 95.21%,89.59%and 79.06,respectively(P<0.001).Multivariate linear regression analysis showed that only preoperative GFR of the affected renal(P<0.001)and WIT(P<0.001)were significantly associated with recovery from ischemia.The recovery fro m ischemia rate decreased by 8.68%for every 10min increase in warm ischemia.Conclusion1.The parenchymal volume preserved is the strongest modifiable determinant of the ultimate postoperative renal function,and WIT,as a continuous variable,also plays an important role.2.Prolonged warm ischemia was associated with decreased postoperative recovery from ischemia.On average,the recovery from ischemia rate decreased by 8.68%for every10min increase in warm ischemia.3.While ensuring the complete resection of the tumor,more normal renal parenchyma should be retained as far as possible,and WIT should be controlled within 30min as far as possible. |
