Effect of stent oversizing on in-stent stenosis and lumen size in normal porcine veins.
OBJECTIVE
To present an in vivo evaluation of the effects of stent oversizing on in-stent stenosis and on actual lumen size in normal veins.


METHODS
Twelve self-expanding stents were implanted in the common iliac veins of 6 minipigs, which were divided in 2 groups for follow-up at 1 and 3 months, respectively. Oversizing ranged from 119.5% to 216% of the original vessel diameter. Intravascular ultrasound (IVUS) was used to measure vessel areas at the stent edges and midpoint. In-stent stenosis and decrease in actual lumen size were evaluated with IVUS immediately after implantation and during follow-up.


RESULTS
There was a very strong positive linear regression between stent oversizing and in-stent stenosis in the 1-month model (r=0.947, p=0.004), in the 3-month model (r=0.931, p=0.007), and in the sum of these 2 groups (r=0.83, p<0.001). Regarding the change in actual lumen size, we found a strong negative linear regression with stent oversizing in the 1-month (r=-0.754, p=0.083) and the 3-month (r=-0.562, p=0.246) groups, but these did not attain statistical significance. However, a strong correlation between stent oversizing and a decrease in lumen size in all samples proved to be statistically significant (r=0.619, p=0.032).


CONCLUSIONS
Stent oversizing was strongly correlated with increased in-stent stenosis and decreased actual lumen size at follow-up in normal non-stenotic porcine veins.
Zamora
Carlos Armando
CA
Department of Radiology, Kobe University School of Medicine, Kobe, Japan. armando@med.kobe-u.ac.jp
Sugimoto
Koji
K
Yamaguchi
Masato
M
Sugimura
Kazuro
K
D000704:Analysis of Variance; D000800:Angioplasty, Balloon / Q000295:instrumentation*; D000818:Animals; D001707:Biopsy, Needle; D004867:Equipment Design; D004868:Equipment Failure; D004869:Equipment Safety; D007084:Iliac Vein / Q000000981:diagnostic imaging* / Q000473:pathology; D007150:Immunohistochemistry; D016014:Linear Models; D008297:Male; D023421:Models, Animal; D011336:Probability; D012008:Recurrence; D012016:Reference Values; D012680:Sensitivity and Specificity; D015607:Stents / Q000009:adverse effects*; D013552:Swine; D018084:Ultrasonography, Interventional