Percutaneous vascular stent: experimental studies and preliminary clinical results in peripheral arterial diseases.

A new pattern of metallic intravascular stent has been experimentally and clinically tested. When the stent is percutaneously placed through a six french introducer, it is held against the vessel wall by its natural elastic properties. In 28 animals, 47 stents of different sizes (from 3 to 5 mm of luminal diameter and from 1.5 to 5 cm of length) have been implanted in the femoro-popliteal (16), the coronary (20), the carotid (3) and the renal arteries (5) and in 3 femoral veins. Angiographic and histological results have shown the stent's low thrombogenicity when it is well fit to the vessel's caliber. Moreover, they have shown its incorporation to the vessel wall by intimalisation as early as the third week after its implantation. The collateral vessels which covered by the stent remain permeable. At the end of this experimentation, 10 implants have been achieved in 8 patients (4 recurrences of iliac stenosis and 6 femoral stenosis). The angiographic results show the perfect tolerance of the organism at 6 months. This good tolerance is revealed by a thin intraluminal border which does not change the artery's diameter. This confirms the experimental results. The permeability is good except for two patients who had an obliteration after one month (one iliac and one femoral obliteration).