Elastic recoil following percutaneous transluminal coronary angioplasty and Palmaz-Schatz stent implantation

The post-procedural elastic recoil in 133 lesions treated with the Palmaz-Schatz stent was compared to 133 matched lesions treated with balloon angioplasty to determine the role of prevention of elastic recoil in the creation of a larger initial luminal diameter. Elastic recoil was defined as the difference between the maximal diameter of the inflated balloon and the minimal luminal diameter of the dilated segment immediately after the procedure and was evaluated by quantitative coronary angiography. Overdilatation was defined as a dilatation induced by a balloon with a maximal diameter larger than the pre-procedure reference diameter. The percent diameter stenosis was reduced from 73% to 31% in the balloon angioplasty group and from 72% to -4% in the stent group (31% vs. -4%, p < 0.01). Elastic recoil was significantly larger in the balloon angioplasty group than in the stent group (0.94 +/- 0.29 mm vs. 0.09 +/- 0.09 mm, p < 0.01). Overdilatation and lesion morphology had no significant effects on elastic recoil in the stent group. In the balloon angioplasty group, overdilatation, noncalcified lesions and eccentric lesions were associated with increased elastic recoil. These results indicated that the larger post-procedural luminal diameter associated with the Palmaz-Schatz stent was primarily the result of prevention of elastic recoil, which was not influenced by the degree of overdilatation or lesion morphology.