Changes of fluid-dynamic parameters in peripheral stenoses with transcutaneous interventions

Peripheral vessels provide a useful in vivo haemodynamic model allowing evaluation of local intravascular fluid dynamics. Velocity measurements using a 0·018 inch Doppler-tipped angioplasty guidewire, quantitative angiography and laboratory data were gathered from 45 patients with a total of 48 percutaneous transluminal laser assisted angioplasties (PTLA) in the superficial femoral, in the iliac, in the popliteal artery and in the peroneal artery. From these data, blood flow, whole blood viscosity, Reynold's numbers, Womersley numbers and shear stress were calculated, evaluated as to their change post PTLA and correlated with clinical improvement at early follow-up. The clinical result was quantified as categorial improvement according to the American Heart Association guidelines. The primary angiographic results of angioplasty were satisfactory in all patients. Clinically 17/45 patients showed a marked, 6/45 a moderate, 18/45 a minimal, and 4/45 no improvement. The mean values of maximnal peak velocity at stenosis decreased from 235 ± 28 cm.s-1 to 84 ± 8 cm.s-1 after PTLA (P < 0·01). The minimal intrastenotic cross section increased from 7·7 ± 0·9 to 21·9 ± 1·6 mm2 (P