In order to elucidate risk factors in arteriosclerosis obliterans (ASO), histories and physical and laboratory findings were reviewed in 163 patients with ASO, and the results were compared with ischemic heart disease (IHD) patients. Patients with ASO were much older and smoked more than patients with IHD. Such complications as hypertension, cerebrovascular disease were significantly more frequent in ASO patients than in IHD patients. On the other hand, the levels of serum total cholesterol, triglycerides, Apo A-II and Apo B were significantly lower in ASO patients than in IHD patients, although lipoprotein(a) tended to be higher in ASO. In ASO, remnant-like particles cholesterol tended to be higher when other presumable atherosclerotic risk factors were absent. The present results indicate that male gender, aging, smoking habit, hypertension and cerebrovascular disease are major risk factors in ASO patients. Although abnormal lipid metabolism may contribute to the development of ASO, we postulate that it plays a less significant role in IHD.

We determined cross sectional area of stent and lumen of iliac arterial lesions before and after deployment of Palmaz stents using intravascular ultrasound (IVUS). Stent deployment was performed in 43 patients with 47 lesions. Cross sectional images were recorded using IVUS in the proximal (P), center (C), and distal portion (D) of the stent in the iliac lesions before, immediately after, and 6 months after the deployment of stent. The initial success rate was 100%. Ultrasound images were analyzed for lumen, intra-stent and intimal proliferation area.The lumen area dilated significantly from 9.9±7.1mm² to 32.7±9.4 after the stent deployment. The intra-stent cross sectional area right after the treatment did not show any difference among the 3 portions. The mean stent area after 6 months was 32.8±8.4mm², without significant stent recoil. The lumen (=intra-stent) area after stent deployment were P: 338±9.7mm², C: 30.9±9.0, and D: 32.7±8.6. The lumen of the center portion had a tendency to be smaller than that of the proximal or distal portions. After 6 months, the intra-stent area was P: 33.5±9.2mm², C: 31.5±7.7, and D: 33.3±8.3 and the lumen area was P: 31.3±10.4mm², C: 28.2±8.9, and D: 29.4±10.5. Stent recoil was not observed but minimal dilatation was noted in the center and distal portions. The lumen area after 6 months became smaller than that immediately after the treatments due to intimal proliferation and stent deformation. The lumen area in the center portion had a tendency to be smaller than that of the proximal portion. The rates of change in the lumen area were P: -6.7±5.6%, C: -98±6.4% and D: -12.4±9.9. This showed a tendency for the lumen of the distal portion to be smaller than that of the proximal portion due to intimal proliferation. The intimal proliferation rates showed a tendency to be higher toward distal sites, but the narrowest portion in the stent was its center. The long-term patency diagnosed by angiography was 92.3% in 6 months and 89.5% in 12 and 24 months. IVUS is useful for evaluation of iliac stent deployment. The Palmaz stent was a very effective treatment for the iliac arterial lesions, protecting against vascular recoil.