Quantitative angiographic assessment of elastic recoil after percutaneous transluminal coronary angioplasty

Little is known about the elastic behavior of the coronary vessel wall directly after percutaneous transluminal coronary angioplasty (PTCA). Minimal luminal cross-sectional areas of 151 successfully dilated lesions were studied in 136 patients during balloon inflation and directly after withdrawal of the balloon. To circumvent geometric assumptions about the shape of the stenosis after PTCA, a videodensitometric analysis technique was used for the assessment of vascular cross-sectional areas. Elastic recoil was defined as the difference between balloon cross-sectional area of the largest balloon used at the highest pressure and minimal luminal cross-sectional area after PTCA. Mean balloon cross-sectional area was 5.2 ± 1.6 mm2 with a mean minimal cross-sectional area of 2.8 ± 1.4 mm2 immediately after inflation. Oversizing of the balloon (balloon artery ratio >1) led to more recoil (0.8 ± 0.3 vs 0.6 ± 0.3 mm, p < 0.001), suggestive of an elastic phenomenon. A difference in recoil of the 3 main coronary branches was observed: left anterior descending artery 2.7 ± 1.3 mm2, circumflex artery 2.3 ± 1.2 mm2 and right coronary artery 1.9 ± 1.5 mm2 (p < 0.025). The difference was still statistically significant if adjusted for reference area. Thus, nearly 50% of the theoretically achievable cross-sectional area (i.e., balloon cross-sectional area) is lost shortly after balloon deflation.