A new self-expansive intraurethral stent using shape memory alloy: A preliminary report of its availability

We describe a new stent made from shape memory alloy (SMA) first devleoped by our collaborative group, its structure, and a simple and easy procedure for its placement and removal without the need for a monitoring system or sedation. The stent made of SMA was placed in 5 dogs for 10 months. It was left in situ in the shape of thermal expansion while the obturator Foley catheter was removed. Placement and removal of the stent was very easy and quick on each occasion in all 5 dogs. No proximal or distal dislodgement was observed in 5 dogs during the indwelling period. There was no encrustation or calcification on the surface of the stent at its removal. These preliminary results suggest that the SMA spiral stent might be an alternative for the relief of prostatic obstruction and be well tolerated in patients with bladder outlet obstruction. The SMA spiral stent is being developed for clinical use.