How does angioplasty work? Serial analysis of human iliac arteries using intravascular ultrasound: Losordo DW, Rosenfield K, Pieczek A, Baker K, Harding M, Isner JM. Circulation 1992;86:1845-58

Abstract

Losordo DW, Rosenfield K, Pieczek A, Baker K, Harding M, Isner JM. Circulation 1992;86:1845-58. Background: The study was performed on patients undergoing angioplasty of iliac artery lesions to document in vivo the mechanism of luminal enlargement. Most of the data that are available regarding this topic have been developed with animal models, postmortem specimens, or occasional histologic sections from fatal clinical procedures. Methods and Results: Images from 40 consecutive patients with iliac artery stenoses treated with balloon angioplasty were obtained with intravascular ultrasonography before and after the angioplasty. The areas of the arterial wall, plaque, lumen, and areas resulting from angioplasty-induced plaque fractures were measured immediately after angioplasty in vivo and compared with findings recorded immediately before angioplasty. Angioplasty increased luminal cross-sectional area from 11.5 ± 0.6 mm2 before angioplasty to 25.4 ± 1.2 mm2 after angioplasty (p = 0.0001). The components of the neolumen was 15.4 ± 0.8 mm2 for the area, excluding plaque fractures, plus 10.0 ± 0.8 mm2 for the area of the neolumen within the angioplasty-induced plaque fractures. The area contained within the plaque fracture accounted for 71.9% of the 13.9 mm2 increase in luminal cross-sectional area after the angioplasty. Analysis of the cross-sectional area of the vessel occupied by atherosclerotic plaque revealed that plaque volume decreased from 33.8 ± 1.8 mm2 before angioplasty to 22.5 ± 1.5 mm2 after angioplasty (p = 0.0001). The plaque cross-sectional area was reduced by 1.3 ± 1.1 mm2 by the balloon dilation. Total artery cross-sectional area increased slightly from 45.3 ± 2.6 mm2 before angioplasty to 47.8 ± 2.0 mm2 (p = 0.00025). Summary: The in vivo analysis of iliac stenoses by intravascular ultrasonography before and immediately after angioplasty demonstrated that plaque fracture and compression of atherosclerotic plaque are important factors involved in the increased luminal diameter resulting from balloon angioplasty. Stretching of the arterial wall also provides a minor increase. Comments: The study reveals quantitative data regarding the mechanism of balloon angioplasty. The article is well illustrated and highlights the significant potential that intravascular ultrasonography has for defining the mechanism and outcome of vascular interventions. Rodney A. White, MD Harbor-UCLA Medical Center Torrance, Calif.