Pj. Fitzgerald et al., Intravascular sonotherapy decreases neointimal hyperplasia after stent implantation in swine, CIRCULATION, 103(14), 2001, pp. 1828-1831
Citations number
20
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Background-Intimal hyperplasia and subsequent in-stent restenosis remain a
major limitation after stent implantation. In vitro cell culture studies sh
ow that low-frequency, noncavitational ultrasound energy may impact smooth
muscle cell proliferation. Accordingly, we assessed the efficacy of intrava
scular sonotherapy treatment on intimal hyperplasia in a swine stent model,
Methods and Results-After balloon injury, biliary stents (Johnson & Johnson
) were implanted in the femoral arteries of 14 swine. A total of 48 stented
sites were randomized to sonotherapy or sham treatment using a custom-buil
t, X-French catheter intravascular sonotherapy system (URX, PharmaSonics In
c). After stent deployment, ultrasound energy (700 KHz) was applied to the
treatment group for lip to 5 minutes. Smooth muscle cell proliferation was
assessed using bromodeoxyuridine histology preparation (BrdU) at 7 days in
28 stented sites. At 28 days, the neointimal thickness and the ratio of neo
intimal/stent area (percent stenosis) was calculated by histomorphometric q
uantification in 20 stented sites. At 7 days, percent of BrdU staining was
significantly reduced in the sonotherapy group compared with the sham group
(24.1 +/-7.0% versus 31.2 +/-3.0%, P<0.05). At 28 days, percent stenosis w
as significantly less in the sonotherapy group than in the sham group (36<p
lus/minus>24% versus 44 +/- 27%, P<0.05), and the mean neointimal thickness
in the sonotherapy group was less than in the sham group (417<plus/minus>4
61 mum versus 643 +/- 869 mum, P=0.06).
Conclusions-In this swine peripheral model, intravascular sonotherapy seeme
d to decelerate cellular proliferation and decrease in-stent hyperplasia. T
herefore, intravascular sonotherapy may be an effective form of nonionizing
energy to reduce in-stent restenosis.