The study of selective segmental renal artery clamping aggravating pathological injury of the solitary-kidney in a porcine model / 中华泌尿外科杂志

ABSTRACT

Objective To evaluate the effect of selective segmental renal artery clamping ( SSRAC) on the solitary-kidney, providing a foundamental basis for the using of SSRAC in partial nephrectomy. Methods A total of 18 pigs were randomized equally into 2 groups according to the method of renal artery clamping such as main renal artery clamping ( MRAC) group or SSRAC group.Each case underwent right radical nephrectomy and either MRAC or SSRAC for 60 minutes on the left kidney.Serum creatinine ( SCr) and blood urea nitrogen (BUN) were measured before surgery and at 6 time points thereafter (the 1st, 7th, 14th, 21st, 28th, 90th day).Magnetic resonance imaging was performed before surgery and at 4 time points thereafter (the 1st, 7th, 28th, 90th day) and T2 relaxation time and apparent diffusion coefficient (ADC) were determined.Inflammatory cell infiltration and interstitial fibrosis were detected using renal histology on the 1st and 90th day after operation.Results SCr and BUN of the two groups increased to peak value on the 1st day, and then decreased gradually to normal on the 90th day after the operation.On the 1st day, SCr [(266.43 ±31.12)umol/l] and BUN [(13.63 ±2.54)mmol/l)] of SSRAC group were significantly lower than that of MRAC [(386.37 ±40.40)umol/l,(26.83 ±5.96)mmol/l] (P0.05) on the 7th, 14th, 21st, 28th, 90th day.In the MRAC group, the T2 relaxation time of upper, middle and lower pole of the left kidney increased and the ADC decreased on the 1st day after operation.It arrived to the peak value on the 7th day, and decreased or increased respectively from then on to normal level on the 90th day.In the SSRAC group, there were no significant changes of T2 relaxation time and ADC in the upper and middle pole of left kidney (P>0.05), but it was similar to that in the MRAC group for lower pole.On the 1st, 7th, 28th day after operation, the T2 relaxation time of upper and middle pole of the left kidney in the MRAC group [(45.50 ±1.87),(51.82 ±2.27), and(40.37 ±1.93)ms ) ] were significantly higher than those in the SSRAC group [(36.67 ± 1.33),(35.15 ±1.27), and(37.48 ±1.37)ms](P0.05).On the 1st, 7th, 28th day after operation, the ADC of upper and middle pole of the left kidney in the MRAC group [(2.29 ±0.08) ×10 -3 mm2/s, (2.10 ±0.08) ×10 -3 mm2/s, (2.41 ±0.09) ×10 -3 mm2/s] were significantly lower than that of the SSRAC group [(2.69 ± 0.08) ×10 -3 mm2/s, ( 2.63 ±0.06 ) ×10 -3 mm2/s, ( 2.68 ±0.05 ) ×10 -3 mm2/s ] ( P <0.05 ) . However, on the 1st,7th, 28th, 90th day after operation, the ADC of lower pole of the left kidney in the SSRAC group [(1.93 ±0.08) ×10 -3mm2/s,(1.91 ±0.09) ×10-3mm2/s,(2.33 ±0.07) ×10 -3mm2/s, and (2.43 ±0.07) ×10 -3 mm2/s] were significantly lower than those of the MRAC group [ (2.37 ±0.05) ×10 -3 mm2/s, (2.06 ±0.07) ×10 -3 mm2/s, (2.46 ±0.09) ×10 -3 mm2/s, (2.61 ±0.08) ×10 -3 mm2/s](P<0.05).The whole left kidney in MRAC group experienced extensive tubular hydropic degeneration and limited inflammatory cell infiltration on the 1st day after operation.Moreover, renal tubular hydropic degeneration alleviated and no glomerular changes, fibrous tissue hyperplasia or inflammatory cell infiltration was found on the 90th day after operation.In SSRAC group, no changes were found in upper and middle pole of left kidney at the two time points, while the pathological injury of the lower pole of left kidney was more severe.Conclusions SSRAC has obvious protective effect on renal function in the early stage. However, compared with MRAC, the renal tissue injury in the ischemic area was more serious.Therefore, to protect renal function in partial nephrectomy, the ischemic renal area should be reduced as much as possible, even to zero-ischemic, when adopting SSRAC.