This study evaluated the effect of intravenous recombinant desulphatohirudin (CGP 39393) on restenosis after balloon angioplasty of focally atherosclerotic femoral arteries in 29 rabbits. At angioplasty, the animals received heparin (150 U/kg bolus, n=16) or hirudin (1 mg/kg bolus, 1 mg/kg infusion first hour, 0.5 mg/kg second hour; n=13). Angiograms performed before and after angioplasty and before sacrifice were analyzed quantitatively. Rabbits were sacrificed 2 hours (n=14) or 28 (n=15) after angioplasty. The mean reduction in angiographic luminal diameter at 28 day postangioplasty (vs. postangioplasty) was less in the recombinant hirudin (r-hirudin) group than in the heparin group (absolute change: 0.30+/-0.33 mm vs. 0.92+/-L=0,61 mm, p=0.01). Blinded planimetric analysis of Movat-stained histologic sections also showed less luminal narrowing in cross-sectional area by plaque in the r-hirudin group (22+/-16% vs. 48+/-29%, p=0.01). In summary, animals receiving recombinant desulphatohirudin at angioplasty had less restenosis by angiography and less narrowing as determined by quantitation of atherosclerotic plaque at necropsy.