Experimental studies in pelviureteric obstruction and hydronephrosis

The 'cellophane sclerosis' phenomenon was used to produce a slowly progressive pelviureteric obstruction in dogs. One group of the resulting hydronephrotic kidneys was treated by non dismembered pelvioplasty, the other by dismembered pelvioplasty. In order to establish some theoretical support for the prevailing clinical preference for the dismembered technique, postoperative results were compared in these groups. Criteria used were perfusion pressure profiles of the pelviureteric segment, still X-ray, fluoroscopy with videorecording, pathology and biochemistry. Scanning electron microscopy and video-densitometry were also introduced. Pressure profiles showed no significant difference after the two types of surgery. Still X-ray in the dismembered group shows a better anatomical result in the pelviureteric segment but suggests more extensive loss of renal parenchyma. X-ray videography in the non dismembered group shows irregular contours of the lumen with saccular pouches ('dogears'). In the dismembered group the pelviureteric segment can hardly be distinguished from that in the normal situation. Functionally however, no clear difference is observed between the two. Microscopy shows more fibrosis in the scar after dismembered operations. However, sufficient muscular tissue had regenerated for normal peristaltic waves to run across the scar in both groups. The epithelium had healed completely in both groups. Scanning electron microscopy shows 'thinning out' of the pelvic urothelium to only one layer in the hydronephrotic stage. Videodensitometry shows a resumption of coordinated peristaltic waves across the scar in both groups.