Comparison of different lasers in terms of thrombogenicity of the laser-treated vascular wall

The thrombogenic properties of the laser‐treated vascular wall are reported as quantitatively assessed on the basis of 33 experiments with peripheral canine vessel segments. Three types of surfaces, namely, (1) intact, (2) mechanically de‐endothelized, and (3) postlaser, have been simultaneously exposed to platelet‐enriched plasma in a sequentially organized artificial circulation system. Then the adherent platelets have been counted on the treated surfaces, and the relative thrombogenicity index has been calculated according to the equation T = (A1 – Aint)/(Ad – Aint), where Aint, Ad, A1 = the adherent platelet counts on intact, mechanically de‐endothelized, and laser‐treated surfaces, respectively. The following lasers have been evaluated: (1) Nd‐YAG, 1,060 nm, continuous wave, 4 W; (2) argon‐ion, 480 and 514 nm and argon‐ion, 350 nm, continuous‐wave, 1 W and 400 nW, respectively; (3) excimer XeCl, 308 nm, pulsed, 30 mJ per pulse, repetition rate 100 Hz; and also (4) the laser‐heated metal probe (2 mm diameter, Trimedyne, Nd‐YAG) 1,060 nm, 8 W. The thrombogenicity index values obtained were 83 ± 7, 72 ± 8, 57 ± 9, 63 ± 7, and 82 ± 9%, respectively. The differences between these values were statistically insignificant. The data are suggestive of the essential requirement of, at least, anticoagulant therapy after laser angioplasty irrespective of the laser type.