The Effects Analysis Of Warm Ischemia Time Influencing Early Renal Function After Laparoscopic Partial Nephrectomy

Objective:To assess the effect of variable durations of warm ischemia time on early renal function after laparoscopic partial nephrectomy(LPN) in patients and make the definite safety duration of renal warm ischemia time.Methods:Retrospective analysis the clinical data of 76 patients treated with LPN in our hospital from October 2012 to June 2014.Patients were divided into 3 groups based on warm ischemic time,namely group A (28 cases) with warm ischemia time less than 20 minutes, group B (34 cases) with warm ischemia time more than 20 minutes and less than 30 minutes, group C (14 cases) with warm ischemia time more than 30 minutes.LPN was performed with renal artery clamping alone in all patients.Preoperative and postoperative renal scintigraphic scan to access Glomerular filtration rate(GFR) was performed in all patients using 99Tcm-Diethylenetetraminepentaacetic acid(99Tcm-DTPA). The GFR values were compared among before, 1week,1 month and 3 months after operation. Make the definite safety duration of renal warm ischemia time and observe the early renal function recovery.Find the factors predicting the early renal function injury by multivariate regression analysis.Results:(1) The operated-side renal GFR underwent LPN decreased 19.43(17.70,22.06)ml/ min for a week、17.04(13.94,20.70)ml/min for a month、13.82(10.72,18.73)ml/min for three months in group C,respectively. In group A The operated-side renal GFR decreased 12.07(10.91,13.42)ml/min for a week、10.04(9.16,11.75)ml/min for a month、 8.44(7.07,9.72)ml/min for three months,respectively.In group B The operated-side renal GFR decreased 13.64(12.48,16.72)ml/min for a week、10.29(9.17,14.27)ml/min for a month、9.63(7.85,12.59)ml/min for three months, respectively.The decreased degree in group C was more than in group A,B(P<0.05)(2) The normal contralateral renal GFR increased 7.00(6.39,10.88)ml/min for a week、6.57(5.68,8.00)ml/min for a month in group C,compared with 3.70 (3.07,4.78) ml/min for a week、3.59(1.73,5.07)ml/min for a month in group A and 3.74(2.92,5.83) ml/min for a week、4.01(2.25,6.02)ml/min for a month in group B,respectively. The increased degree in group C was more than in group A,B (P<0.05).However,the differences of the normal contralateral renal GFR in three groups were not significant for three months(P>0.05)(3) The total renal GFR decreased (10.70±4.93) ml/min for three months in group C,compared with (5.64±4.12) ml/min in group A and (6.37±4.32) ml/min in group B,respectively. The decreased degree in group C was more than in group A,B (P<0.05). However,the differences of the total renal GFR in three groups were not significant for a week and a month(P>0.05)(4) The multivariate regression analysis revealed that warm ischemia time was the independent risk factor of postoperative the early renal function injury.Conclusions:(1) Warm ischemia time is the major factor of the early renal function injury after laparoscopic partial nephrectomy.(2) Warm ischemia time more than 30 minutes not only greatly injury the renal function but also recover the renal function slowly.