[Mechanisms of transluminal mechanical coronary recanalization].

Coronary angioplasty (PTCA) represents one of the most diffuse technique for myocardial revascularization in coronary artery disease patients. The principal mechanisms, responsible for the luminal increment after successful balloon dilatation are stretching of the vessel wall and splitting of the plaque and its rearrangement in an increased cross section of the vessel. Soon after balloon deflation elastic recoil of the vessel wall might occur at different grades which result in a partial loss of the result achieved by balloon PTCA. This phenomenon seems to be one of the major factors influencing the acute and long-term results of PTCA. Balloon inflation is also followed by endothelial denudation and intramural hemorrhage and intramural thrombus apposition. Then, a proliferative process takes place which is characterised by intimal and smooth muscle proliferation and migration. This process, beside the elastic recoil of the vessel wall, might also contribute to restenosis following balloon PTCA. Other devices for myocardial revascularization were introduced in the clinical practice based on different mechanisms from that of conventional PTCA. Transluminal atherectomy (directional, rotational and rotational-ablation) is based on the removal of plaque material from the vessel, increasing the lumen and creating a smooth surface. By this mechanism of action, plaque splitting and vessel wall stretching might be avoided, thus acute and long-term results are supposed to be improved as compared to balloon angioplasty. Another device for the removal of plaque material is represented by laser angioplasty which utilizes laser energy for the evaporation of the atherosclerotic material and the increase of vessel lumen without vessel wall stretching and plaque splitting.(ABSTRACT TRUNCATED AT 250 WORDS)