Angioplasty is considered as an alternative to surgical reconstruction of arteriosclerotic vessels especially since
lasers and atherectomy devices have become clinically available. However, the resulting arterial injury may lead to acute thrombotic occlusion and chronic restenosis because of hyperplastic vascular repair. The purpose of this experimental study was to evaluate the consequences of thermal
laser arterial injury on platelet deposition and myointimal
hyperplasia in dog femoral arteries. An intraarterial, short-term
prostacyclin (PGI2) infusion was given to evaluate the antithrombotic and antiproliferative effects of this
drug. Severe arterial
necrosis, partly carbonized and vacuolized, extending to the adventitia was induced by a transluminal heated
laser probe motion. The platelet deposition after one hour was 33.62 +/- 6.56 (x 10(6)/cm2.) (mean +/- SEM) without
prostacyclin, after 40 ng/kg/min
prostacyclin (PGI2) 24.70 +/- 5.45 and after 400 ng/kg/min 9.3 +/- 2.26 (p less than 0.005 no PGI2 vs 400 ng/kg/min PGI2). Myointimal
hyperplasia was present eight weeks after thermal
laser vascular injury independent of the initially administered
prostacyclin. In conclusion, acutely thrombotic and chronically hyperplastic femoral arteries were found following transluminal thermal arterial injury in dogs.
Prostacyclin administration could be clinically beneficial in reducing acute vascular
thrombosis following thermal angioplasty. Short-term use of this substance, however, may not prevent a hyperplastic response to angioplasty.