Progressive vascular remodeling and reduced neointimal formation after placement of a thermoelastic self-expanding nitinol stent in an experimental model
Autor: | John R. Laird, Julie A. Kovach, Karen Pierce, Andrew J. Carter, Kevin Heath, Renu Virmani, Kathy Hess, Andrew Farb, Douglas S. Scott, Lynn Bailey, Timothy G. Hoopes |
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Rok vydání: | 1998 |
Předmět: |
medicine.medical_specialty
medicine.diagnostic_test urogenital system business.industry medicine.medical_treatment Stent Miniature swine equipment and supplies medicine.disease Balloon Surgery Stenosis Restenosis Intravascular ultrasound Balloon dilation Medicine cardiovascular diseases Implant Cardiology and Cardiovascular Medicine business Nuclear medicine |
Zdroj: | Catheterization and Cardiovascular Diagnosis. 44:193-201 |
ISSN: | 1097-0304 0098-6569 |
DOI: | 10.1002/(sici)1097-0304(199806)44:2<193::aid-ccd13>3.0.co;2-o |
Popis: | Despite the improvements afforded by intracoronary stenting, restenosis remains a significant problem. The optimal physical properties of a stent have not been defined. We compared the vascular response to a thermoelastic self-expanding nitinol stent with a balloon-expandable tubular slotted stainless steel stent in normal porcine coronary arteries. Twenty-two stents (11 nitinol and 11 tubular slotted) were implanted in 11 miniature swine. The nitinol stents were deployed using the intrinsic thermal properties of the metal, without adjunctive balloon dilation. The tubular slotted stents were implanted using a noncompliant balloon with a mean inflation pressure of 12 atm. Intravascular ultrasound (IVUS) and histology were used to evaluate the vascular response to the stents. The mean cross-sectional area (CSA) of the nitinol stents (mm2) as measured by IVUS increased from 8.13 ± 1.09 at implant to 9.10 ± 0.99 after 28 days (P = 0.038), while the mean CSA of the tubular slotted stents was unchanged (7.84 ± 1.39 mm2 vs. 7.10 ± 1.07 mm2, P = 0.25). On histology at 3 days, the tubular slotted stents had more inflammatory cells adjacent to the stent wires (5.7 ± 1.5 cells/0.1 mm2) than the nitinol (3.9 ± 1.3 cells/0.1 mm2, P = 0.016). The tubular slotted also had increased thrombus thickness (83 ± 85 μ) than the nitinol stents (43 ± 25 μ, P = 0.0014). After 28 days, the vessel injury score was similar for the nitinol (0.6 ± 0.3) and the tubular slotted (0.5 ± 0.1, P = 0.73) designs. The mean neointimal area (0.97 ± 0.46 mm2 vs. 1.96 ± 0.34 mm2, P = 0.002) and percent area stenosis (15 ± 7 vs. 33 ± 7, P = 0.003) were significantly lower in the nitinol than in the tubular slotted stents, respectively. We conclude that a thermoelastic nitinol stent exerts a more favorable effect on vascular remodeling, with less neointimal formation, than a balloon-expandable design. Progressive intrinsic stent expansion after implant does not appear to stimulate neointimal formation and, therefore, may provide a mechanical solution to prevent in-stent restenosis. Cathet. Cardiovasc. Diagn. 44:193–201, 1998. © 1998 Wiley-Liss, Inc. |
Databáze: | OpenAIRE |
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