Impact on ureteral peristalsis in a stented ureter. An experimental study in the pig
OBJECTIVE To determine whether indwelling JJ stents significantly alter renal pelvic pressure and consequently have deleterious effects on renal function. MATERIALS AND METHODS Thirteen piglets were used totalling 26 renal units. Using an open, sterile surgical procedure, 23 renal units were stented with 6 F JJ catheters of eight different types: three renal units were not stented and served as controls. Intra-pelvic pressure values during diuretic stress were measured before and after 6 weeks of intubation. The kidneys were then removed and sent for pathological evaluation of renal parenchymal thickness. RESULTS A marked increase in intra-pelvic pressure values was found in two of the 19 stented renal units suitable for this measurement. A significant reduction (more than one third with respect to the control values) in renal parenchymal thickness was found in six of the 21 stented renal units suitable for this measurement, three of which had been intubated with a Cook polyurethane stent and three with an Angiomed Puroflex stent. CONCLUSION In the present experimental study some JJ stents seemed to cause long-lasting changes in renal pelvic pressure and consequently to have deleterious effects on renal function. Although experimental findings are not always fully related to clinical practice, a knowledge of the potential effects of these prostheses is essential to minimize complications related to their use.