Objective: To determine the pathophysiological changes in upper urinary tract motility and calculus transit which may occur following JJ stent 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 transit times for complete passage of synthetic calculi from the upper ureter into the bladder.
Results: Acute effects included raised renal intrapelvic pressure, reduced pelvic and ureteric motility and delayed calculus transit time. Prolonged JJ stent placement was associated with return of intrapelvic pressure to normal but persistent changes in both renal and ureteric motility and also calculus transit time.
Conclusion: In situ JJ stents impair upper urinary tract motility and experimental calculus transit time and may delay passage of ureteric calculi or calculus fragments following extracorporeal shock wave lithotripsy.