Drainage and reflux characteristics of antireflux ureteral double-J stents.

We tested three antireflux double-J stents and compared them with common double-J stents in ex vivo canine urinary systems. At a physiologic flow rate, the drainage function of the antireflux stents proved to be sufficient; however, at a supraphysiological flow rate, drainage was inferior to that of the common double-J stent. Our reflux study demonstrated high-grade reflux with the common double-J stent, which transmitted more than 90% of the bladder pressure to the renal pelvis. The antireflux stents prevented this to a certain degree by both a reduction in and a delay of pressure transmission to the renal pelvis. In preliminary clinical trials, vesicorenal reflux was not detectable radiologically with the antireflux stents.