Prostatic urethra dilatation with the Gianturco self-expanding metallic stent: a feasibility study in cadaver specimens and dogs.

In an effort to develop a transcatheter technique for dilatation of the prostatic urethra without the use of balloons, the feasibility of using Gianturco self-expanding stents was evaluated. Initially, eight human cadaveric prostatic urethras were stented to evaluate the ability of the stent to dilate the lumen. In all cases, the device attained its unconstrained diameter immediately on placement. Subsequently, stents were placed in the prostatic urethra of 12 dogs and followed up for 1 month (four dogs), 3 months (one dog), and 6 months (seven dogs). Five bare straight-end prostheses, one nylon-covered straight-end device, and six flared-end stents were used. Three of the bare straight-end stents migrated during the follow-up, whereas the nylon-covered and flared-end stents did not. Stent diameters greater than 1.3 times the urethral diameter caused moderate to marked edema and inflammation. After 6 months, white deposits were found on the solder points, presumably from electrolysis. Our experience suggests that placement of Gianturco self-expanding stents may be a useful method of dilating and maintaining the luminal diameter of the prostatic urethra, although care must be taken to select the proper stent size.