THE EFFECTS OF ACUTE AND CHRONIC JJ STENT PLACEMENT ON UPPER URINARY-TRACT MOTILITY AND CALCULUS TRANSIT

Objective To determine the pathophysiological changes in upper urinary tract motility and calculus transit which may occur following JJ sten t insertion. Materials and methods The acute and chronic effects of JJ stent placement were studied in 24 canine renal units. Intrarenal and intraureteric pressures and motility were measured, in addition to tr ansit times for complete passage of synthetic calculi from the upper u reter into the bladder. Results Acute effects included raised renal in trapelvic pressure, reduced pelvic and ureteric motility and delayed c alculus transit time. Prolonged JJ stent placement was associated with return of intrapelvic pressure to normal but persistent changes in bo th renal and ureteric motility and also calculus transit time. Conclus ion In situ JJ stents impair upper urinary tract motility and experime ntal calculus transit time and may delay passage of ureteric calculi o r calculus fragments following extracorporeal shock wave lithotripsy.