Laser angioplasty: an atherosclerotic swine model.

Rapid production of occlusive, atherosclerotic iliac artery lesions was achieved in 25 of 27 (93%) Yucatan miniature swine, using a combination of high cholesterol diet and mechanical endothelial denudation. Animals were fed a diet with 2% of their calories as raw cholesterol 2 weeks prior to balloon denudation of iliac arteries, which resulted in atherosclerotic lesions within 8 weeks. Early after denudation we have demonstrated total occlusion of arteries by fibrin thrombi, which in time organize and ultimately result in fibrotic occlusive disease. The arterial walls and intima show varying degrees of foam cell infiltration with destruction of the internal elastic lamina and calcification. Totally occluded lesions show fibrointimal proliferation, fibrosis, and multiluminal channels, which are probably secondary to organized thrombus. Our model of occlusive iliac artery disease involving vessels of 1 to 3 mm in diameter allows the development of catheter systems suitable for use in human peripheral and coronary arteries. This model is useful for the study of angioplasty, whether mechanical, balloon, or laser-mediated.

Objective benefit of nifedipine in the treatment of Raynaud's phenomenon. Double-blind controlled study.

To compare the effects of the calcium channel antagonist, nifedipine, with that of placebo, a randomized double-blind crossover study was performed in 11 patients with moderate to severe Raynaud's phenomenon. Digital skin temperature recovery time was measured after immersing the patient's hand in ice water for 20 seconds. Patients were randomly assigned to receiving either nifedipine or placebo for one week, followed by the crossover phase. Skin temperature recovery time was also measured in 21 normal volunteers. The mean time to recovery for patients taking nifedipine was 28.5 +/- 20.8 minutes versus 44.9 +/- 18.9 minutes for patients receiving placebo (p less than 0.05 by analysis of variance with repeated measures). The mean time to recovery for the normal volunteers was 11.3 +/- 7.2 minutes versus 40.2 +/- 19.9 minutes for the patients (p less than 0.01 by the Student t test). Nine of the 11 patients noted improvement of symptoms during treatment with nifedipine. It is concluded that nifedipine is an effective, well-tolerated treatment for Raynaud's phenomenon.