Prototype of a reflux-preventing ureteral stent and its clinical use

We have experimentally produced a ureteral stent which prevents vesicorenal reflux. This stent has a thin silicon sleeve at its distal end (intravesical portion). In a model experiment the sleeve demonstrated an excellent capability to prevent reflux. The sleeve allowed flow of fluid with minimal pressure rise. A patient with bilateral ureteral obstruction was managed with endoscopic insertion of a sleeved stent in the right ureter and a usual pigtail stent in left ureter. During cystography vesicorenal reflux was not observed on the right side while reflux occurred on the left side. Excretory urography forty days after stent placement demonstrated recovery of renal function and maintenance of drainage in both renal units. Thus, the drainage characteristic of this stent appears to be approximately the same as that of usual stent.