A NEW SELF-EXPANDABLE AND REMOVABLE METAL STENT FOR BILIARY OBSTRUCTION - A PRELIMINARY-REPORT

We report our experience with a new self expandable metallic stent, a coil spring made from a nickel-titanium alloy. The super elastic chara cteristic of this metal offers a very strong radial force and previous dilatation of biliary strictures is not necessary. The stent is endos copically inserted constricted over an introducing catheter, expanding spontaneously after release to its original 8 mm diameter. During the last six months, eleven stents were inserted in nine patients with pa ncreatic carcinoma to relieve jaundice. Another stent was percutaneous ly implanted treating a benign stricture in a patient with a choledoch ojejunostomy after a Whipple operation. Clinical improvement was achie ved in all the patients except in one who died from liver metastases 5 weeks later. In two patients, although stents were obstructed after 2 and 4 months: from insertion, they were easily removed by pulling the ir distal end through the endoscopic working channel. After a mean fol low up of 4.5 months, patients had no evidence of biliary reobstructio n. Although follow-up is short, these results are encouraging, and thi s new metallic stent seems to have several advantages over the current commercially available ones.