The Vascular Response After Balloon Angioplasty of Infrapopliteal Intermediate Stenosis Evaluated by Optical Frequency Domain Imaging.

Abstract

We often experience worsening of stenosis by balloon angioplasty of infrapopliteal (IP) lesion compared with the initial stenosis. However, reports on this phenomenon are limited. The main purpose of this study is to evaluate vascular response after balloon angioplasty of IP artery stenosis. Thirteen patients (15 arteries) who underwent endovascular treatment (EVT) and follow-up angiography with optical frequency domain imaging (OFDI) of intermediate IP stenosis were included. Serial OFDI images at 3 time points (before and after EVT and at follow-up) were analyzed. Diameter and area of external elastic lamina, internal elastic lamina, and lumen were measured, and plaque area and plaque burden (PB) were calculated. PB before EVT was classified into mild, moderate, and severe by 0%-20%, 21%-40%, and 41%-60%, respectively. Analyzed were 229 cross sections. External elastic lamina diameter did not change significantly among three time points (3.8 ± 0.5 [95% confidence interval (CI): 3.7 to 3.9] mm, 3.9 ± 0.4 [95% CI: 3.8 to 4.0] mm, 3.9 ± 0.4 [95% CI: 3.8 to 4.0] mm, p = 0.06). Lumen area increased after EVT but became smaller at follow-up than before EVT (4.5 ± 1.5 [95% CI: 4.3 to 4.7] mm2, 5.3 ± 1.3 [95% CI: 5.1 to 5.5] mm2, 3.7 ± 1.2 [95% CI: 3.5 to 3.9] mm2, p < 0.001). Plaque area became smaller after EVT and larger at follow-up than before EVT (3.0 ± 1.7 [95% CI: 2.8 to 3.2] mm2, 2.4 ± 1.5 [95% CI: 2.2 to 2.6] mm2, 4.0 ± 1.6 [95% CI: 3.8 to 4.2] mm2, p < 0.001). Lumen area was significantly smaller at follow-up than before EVT in mild and moderate PB groups, but it was not different in severe PB group (mild PB group: 5.1 ± 1.5 [95% CI: 4.7 to 5.5] mm2 vs. 4.0 ± 1.3 [95% CI: 3.7 to 4.3] mm2, p < 0.001, moderate PB group: 4.6 ± 1.3 [95% CI: 4.4 to 4.8] mm2 vs. 3.6 ± 1.2 [95% CI: 3.4 to 3.8] mm2, p < 0.001, severe PB group: 3.0 ± 1.4 [95% CI: 2.5 to 3.5] mm2 vs. 3.1 ± 1.0 [95% CI: 2.7 to 3.5] mm2, p = 0.93). Balloon angioplasty of intermediate IP artery stenosis with mild or moderate PB led to smaller lumen area at follow-up than before EVT.