Renal Functional Outcome After Multiple Tracts Minimally Invasive Percutaneous Nephrolithotomy

Objectives:Retrospective to observe the effects of single tract minimally invasive percutaneous nephrolithotomy(MPCNL)and multiple tracts MPCNL on renal function in the management of upper urinary tract calculi.Patients and Methods :A total of 178 patients with upper urinary tract calculi have involved the study.All patients underwent MPCNL in our institute and were retrospectively evaluated during May 2014 to February 2016.A total of 122(68.5%)patients were managed by single-tract MPCNL(group A).Meanwhile,multiple tract MPCNL were necessary in56(31.5%)patients(group B)including 42(75%)patients performed by double-tract MPCNL,8(14.3%)patients performed three tracts MPCNL and 6(10.7%)patients performed four tracts MPCNL.Serum creatinine(SCr)and treated side glomerular filtration rate(GFR)variations were analyzed with renal scintigraphy using99mTc-diethylene triamine pentaacetic acid(99mTc-DTPA)preoperatively and after at least 6 months of follow-up(FU).Results:The two groups of patients in gender,age,body mass index(BMI),hydronephrosis,CT value of stone and infection on preoperative were not statistically significant.In terms of size of stone,patients of group B were higher than group A(1277.3±787.0 mm2 vs 783.0±605.7 mm2,P=0.000);12(9.8%)patients in group A and 14(25.0%)in group B experienced Clavien grade I complications(fever).It was statistically significant(P=0.008).Perioperative blood transfusion(Clavien grade II)rate occurred in 1.6% and 7.1 %,group A and group B,respectively(p=0.148).One patient in group A required selective renal artery embolization for severe hemorrhage.We managed all complications conservatively.At a mean FU of 7.6 months,SCr dropped from 192.9±151.9 umol/L to167.6±113.9 umol/L(p=0.008)and treated side GFR increased from 29.8±21.2ml/min preoperatively to 32.7±22.5 ml/min postoperatively(P=0.022)in group A.Similarly,SCr dropped from 238.5±130.1 umol/L to 215.8±128.1 umol/L(p=0.013)and treated side GFR increased from 29.6±21.4 ml/min preoperatively to 32.9±25.1ml/min postoperatively(P=0.014)in group B.No statistically significant difference between two groups according to SCr or treated side GFR variation was observed(P>0.05).Conclusions:Stone clearance resulted in improvement of treated side kidney function after single tract or multiple tracts MPCNL.Single tract or multiple tracts MPCNL didn’t show statistically significant difference in treated side renal function postoperative recovery.