Percutaneous transluminal coronary angioplasty--histopathological analysis of nine necropsy cases.

From 1982 to 1984 nine of 300 patients undergoing transluminal coronary angioplasty died. The nine coronary arteries and one saphenous aorto-coronary by-pass graft affected by angioplasty were studied by light microscopy. The following types of lesions were found, frequently in association: rupture of the plaque, circumscribed or reaching to the intimal layer or extending beyond it, dissections (fissures) between arterial layers, intra-plaque haemorrhage, plaque emboli and thrombosis. In two cases the therapeutic approach was considered to be clinically and pathologically successful; the patients survived 24 h (case 6) and forty days (case 4). Case 6 which presented recent lesions indicative of success showed, in contrast with the other non-successful cases, rupture affecting not only the intimal layer but also deeper structures of the arterial wall. There were also more extensive fissures. Case 4 which presented late alterations indicative of success showed a plaque fracture whose borders were kept apart by fibrous tissue. In conclusion, we believe that angioplasty allows the re-establishment of arterial blood flow by provoking deep intimal and medial rupture producing a small fissure between the arterial layers and a widening of the lumen; in cases with good late results these alterations cicatrize leaving a wider arterial lumen.