PARTIAL URETERAL OBSTRUCTION - A NEW VARIABLE AND REVERSIBLE CANINE EXPERIMENTAL-MODEL

Objectives. To develop a new experimental model of partial ureteral ob struction that is simple, reliable, variable, and reversible. Methods. A 6 F ureteral catheter was inserted into the left ureteral orifice a nd was cut 2 cm distal to the orifice. The most distal part of the ure ter was ligated around the catheter. The catheter lumen was partially obstructed by insertion of stylets of three different diameters. The c atheter and the stylet were fixed inside the bladder. The model was te sted in 12 dogs, which were stratified into three groups according to the diameter of the obstructing stylet. All the dogs were subjected to intravenous urography (IVU) and technetium-99m-mercaptoacetyltriglyci ne (Tc-99m-MAG(3)) renal scan at 2 and 4 weeks following induction of partial ureteral obstruction. Results. Three different grades of hydro ureteronephrosis were obtained according to the diameter of the obstru cting stylet. The IVU and Tc-99m-MAG(3) renal scan studies were repeat ed at 2 and 4 weeks following removal of the ureteral catheter and ure teroneocystostomy and showed marked improvement in the configuration a nd function of the corresponding renoureteral units. Conclusions. Our experimental model fulfills the requirements for a useful model of par tial ureteral obstruction, namely, simplicity, reliability, variabilit y, and reversibility.