COMPUTERIZED TOMOGRAPHY OF RENAL PARENCHYMAL DISTURBANCE FOLLOWING NEPHROLITHOTOMY

Abstract

Staghorn calculi were removed by nephrolithotomy with the one-layer interrupted parenchymal suture method designed by Taguchi and renal parenchymal disturbance following the operation were evaluated by computerized tomography. Twenty kidneys in 17 cases were examined pre and postoperatively for changes in the incised and sutured part of the renal parenchyma. (4 kidneys were not examined preoperatively.) No serious complications were found in any cases except for one in which transient renovascular hypertension was developed. The average length of the parenchymal incision was 8.4cm, the average clamping time of the renal pedicle was 27 minutes and 11 seconds, and the interval between operation and CT scanning ranged from 3 weeks to 2 years and 5 months. The postoperative CT scanning demonstrated the low density areas following enhancement and depression of the parenchyma. These changes were classified into the following 3 patterns: Type I-no changes were observed in the parenchyma, or a linear low density area was found (5 kidneys, 25.0%); type II-a long, narrow strip of low density area was found in accord with the excised and sutured part (5 kidneys, 25.0%); and type III-a wedge-shaped low density area or depression of the parenchyma was found (10 kidneys, 50.0%). The length of the parenchymal incision was analysed with reference to these patterns. The length of type I was significantly shorter than that of type II or III (p<0.05).
The clamping time of the renal pedicle in type I was also shorter than that in type II and III, but the differences did not reach a statistically significant level. Type II pattern frequently was found shortly after the operation. It is, however, undeniable that type II may transform to type III. Recently, Plasma Renin Activity (PRA) was determined before and after the operation in 7 cases. None of them showed significant elevation of PRA postoperatively. Althought the one-layer interrupted parenchymal suture method is not anatrophic in a strict sense, it had little influence on the renal parenchyma and dit not complicate renal hypertension, routinly.