Influence of expanded balloon diameter on palmaz‐schatz stent recoil

After successful stent implantation, the residual luminal diameter of the stented vessel is usually smaller than the maximal stent‐expanded balloon diameter. The goal of this study was to determine whether immediate vessel diameter recoil after Palmaz‐Schatz stenting is affected by the final expanding balloon diameter used during stent deployment. Single Palmaz‐Schatz balloon expandable stents were successfully placed in 108 stenotic lesions. There were 68 patients with 75 saphenous vein graft (SVG) and 30 patients with 33 native coronary artery lesions, including 26 restenotic and 82 de novo occlusive (>50% diameter stenosis) lesions. Quantitative coronary angiography was used for the assessment of stent recoil, defined as the difference between the minimal diameter of the fully expanded balloon and the postprocedure minimal lumen diameter divided by minimal diameter of the fully expanded balloon. A strong correlation (r = 0.94) was found between the minimal diameter of the fully expanded balloon and poststenting minimal lumen diameter. Immediate recoil was 11.3 ± 7.5%, responsible on an average for 0.4 ± 0.2‐mm acute lumen loss. Recoil was less in SVG than in coronary arteries (9.7 ± 6.6% vs. 14.0 ± 7.8%; P = 0.004, and 0.3 ± 0.2 vs. 0.4 ± 0.2 mm; p = 0.01). Lesions were divided into four subgroups, based on the final stent expanding balloon diameter: (1) ⩽3.0 mm (n = 33); (2) >3 ± 3.5 mm (n = 43); (3) >3.5 ± 4 mm (n = 23); and (4) >4 mm (n = 9). For the four subgroups, the percentage recoil values were 15.0 ± 5.7, 10.4 ± 8.2, 9.0 ± 5.4, and 4.7 ± 2.0, respectively (P <0.001). Mean values of diameter stenosis, lesion length, maximal balloon pressure, balloon‐to‐artery ratio, relative vessel stretch, and absolute recoil were not statistically different. Immediate vascular recoil in single implanted Palmaz‐Schatz stent is a function of the final expanding balloon diameter, with recoil larger at small‐balloon diameters and almost eliminated at large inflation diameters. This finding could contribute to less acute gain, increased restenosis, and higher stent thrombosis rates after stenting vessels of <3‐mm diameter. © 1995 Wiley‐Liss, Inc.