Influence of inflation pressure and balloon size on the development of intimal hyperplasia after balloon angioplasty. A study in the atherosclerotic rabbit.

Abstract

With the technical assistance of Sue Marie Sanabria and Francesca MigliaccioTo evaluate the effect of balloon size and inflation pressure on acute and subsequent outcome following balloon angioplasty (BA), 70 New Zealand White rabbits with bilateral femoral atherosclerosis were assigned to four groups: group 1, oversized balloon, low inflation pressure (n=35 vessels; balloon size, 3.0 mm/inflation pressure, 5 atm); group 2, oversized balloon, high inflation pressure (n=36; 3.0 mm/10 atm); group 3, appropriate size, low inflation pressure (n = 17; 2.5 mm/5 atm); and group 4, appropriate size balloon, high inflation pressure (n = 19; 2.5 mm/10 atm). Angiograms were obtained before, 10 minutes after, and 28 days after BA and read by two blinded observers using electronic calipers. The in vivo ballon-to-vessel ratio was measured for each group. There were eight non-BA controls. Rabbits were sacrificed either immediately (n=34) or at 28 days after BA (n=36), with the femoral vessels pressure perfused for histologic and morphometric analysis. The 3, 9/17 [53%]; p<O.05). A 3.0-mm balloon resulted in significant oversizing irrespective of inflation pressure (balloon-to-vessel ratio, 1.5+±0.1 vs. 1.1+±0.1 to 1, for the 2.5-mm balloon). Vessels exposed to highinflation pressure had a significantly higher incidence of mural thrombus, dissection (p<0.01), and medial necrosis versus low pressure (p<0.05). At 28 days, the rates of restenosis (defined as greater than 50% loss of initial gain) were 14/20 (70%), 11/16 (69%), 5/10 (50%), and 5/10 (50%) for groups 1 through 4 (p=NS; a trend in favor of the groups using an oversized balloon). There was an increase in the degree of intimal hyperplasia by morphometric analysis in all groups, being most marked in group 2 (oversized balloon and high inflation pressure, 1.7-±0.9 vs. 0.5+±0.2 mm for controls, p<0.001). We reached two conclusions. First, all protocols resulted in a significant increase in luminal diameter immediately after angioplasty with the highest success rate in vessels subjected to high pressure dilatation. Second, the combination of high inflation pressure and an oversized balloon caused the most extensive vessel-wall damage early after BA and the greatest degree of intimal hyperplasia at 28 days. Thus, oversizing the balloon with high inflation pressure may represent a factor causing restenosis following BA.

Mouse Model of Femoral Artery Denudation Injury Associated With the Rapid Accumulation of Adhesion Molecules on the Luminal Surface and Recruitment of Neutrophils

“…The I/M ratios obtained are comparable to those of other animal models. [32][33][34] At 4 weeks, we obtained an I/M ratio of 1.1, higher than those previously reported in mice. 15,20 Of note was a significant decrease in medial area between 2 and 4 weeks after injury.…”

Enhanced Monocyte Tissue Factor Response After Experimental Balloon Angioplasty in Hypercholesterolemic Rabbit: Inhibition With Dietary l -Arginine

“…However, the atherosclerotic rabbit model we used has been demonstrated to have several features in common with human atherosclerosis, and its reproducibility has been demonstrated in several previous studies. 23,37 A diet supplemented with 2% cholesterol results in very high cholesterol levels in this model and severe atherosclerotic lesions and is associated with significant morbidity rates in the animals. The results of the present study might differ in animals with lesser degrees of cholesterol supplementation.…”

Peri/Epicellular Protein Disulfide Isomerase Sustains Vascular Lumen Caliber Through an Anticonstrictive Remodeling Effect

“…22 Iliofemoral overdistension injury was performed by a coronarytype balloon catheter in normolipidemic male rabbits 23 under fluoroscopy, with balloon:vessel ratio of 1.2, which is well within the range of analogous models and human interventions. 24 At day 12 AI, pluronic gel 25% with 1 μg/mL of mouse-IgG or distinct neutralizing anti-PDI antibodies (PDIAb) was applied in the perivascular region at the injury site. After 48 hours, angiography and optical coherence tomography were performed.…”