Restenosis and successful angioplasty: histologic-radiologic correlation.

Histologic analysis was undertaken on 24 perfusion-fixed arteries from New Zealand White rabbits that had undergone percutaneous transluminal angioplasty (PTA) of a focal arteriosclerotic lesion in the femoral artery 1 month earlier. Experiments representative of occlusion, restenosis (greater than or equal to 50% stenosis), a good result (less than 50% stenosis), or aneurysm (as defined angiographically) were randomly selected for histologic analysis. Histologic findings were compared with those in untreated control lesions in the contralateral femoral artery. All good results (n = 11) but only four of seven restenoses had histologic evidence of a tear into the tunica media or the tunica adventitia (P = .017). Cases of tears to the adventitia were more likely to have a good result. New myointimal proliferation was more severe with restenosis (P less than .05). Occlusions and aneurysms appeared to be more severe expressions of the histologic findings observed in restenoses and good results, respectively. An arterial tear is necessary but not sufficient to obtain a good result after PTA; outcome is ultimately dependent on the degree of intimal hyperplasia.