[Excimer laser angioplasty in arterial obstructive disease. Clinical experience with guidewire-controlled catheter systems]

Percutaneous transluminal laser angioplasties (PTLA) were performed in nine patients (7 males, 2 females, aged 52-81 years) with peripheral vascular disease, stages IIB-IV (Fontaine's classification), with 75% stenosis (5 patients) or occlusion (4 patients) in the area of the superficial femoral artery. Two catheter systems were used. One was a monofiber catheter (600 microns) with eccentric guidewire, the other a multifiber catheter with 12 concentrically arranged fibres (200 microns each) and a central guidewire. An XeCl-excimer laser (308 nm), with a pulse duration of 50 ns and pulse frequency of 15-30 Hz, served as the laser source. It was possible in all patients to reduce the stenosis of 75-100% to 35-70% or reopen the occlusion without laser-associated complications. To remove the residual stenosis PTLA was followed by balloon dilatation in seven patients and by application of a Simpson atherectomy catheter in one patient: these measures reduced the degree of stenosis to 20-40%.

[The cardioprotective effect of verapamil in acute percutaneous transluminal coronary angioplasty]

Verapamil improved the ischemic tolerance of the myocardium in experiments in animals. Therefore, 20 patients were examined during percutaneous transluminal coronary angioplasty (PTCA) of a proximal LAD stenosis in order to evaluate the ability of verapamil to improve the ischemic tolerance in man. Before the second dilatation, 1 mg verapamil was given intracoronarily to 10 patients, the other 10 patients received placebo ic. Before and after each of the three inflations, blood samples were obtained from the coronary sinus in five patients of each group to analyze the contents of lactate, pyruvate, and pH. Verapamil caused a significant prolongation of the inflation from 58 +/- 12 s to 83 +/- 20 s. This effect was persistent also during the following inflation (96 +/- 19 s). The onset of angina was delayed (p less than 0.05). ST-wave elevations and T-wave amplitudes were smaller after verapamil, in spite of the increased duration of inflation, as compared with the control group. The time until ST elevations of 0.1 mV occurred was increased from 17 +/- 3 s to 57 +/- 18 s (p less than 0.05). The increase in lactate in coronary sinus blood was less pronounced after verapamil (48% of control; p less than 0.05). Intracoronary verapamil before PTCA of the LAD improved the ischemic tolerance of the poststenotic myocardium significantly as evaluated by measurements of electrocardiographic and metabolic parameters. No side effects occurred during the injection of verapamil into the left coronary artery.