Af. Le Blanche et al., MR-guided PTA in experimental bilateral rabbit renal artery stenosis and MR angiography follow-up versus histomorphometry, CARDIO IN R, 23(5), 2000, pp. 368-374
Purpose: To assess in vivo 1) MR-guided percutaneous transluminal renal ang
ioplasty (PTRA) in experimental bilateral rabbit renal artery stenosis (RAS
); 2) postprocedural follow-up by gadolinium-enhanced MR angiography versus
histomorphometry.
Methods: Fifteen male NZW rabbits of mean weight 4.0 kg (range 3.5-4.2 kg)
underwent bilateral RAS induction by combined overdilation-deendothelializa
tion with a gadolinium-filled balloon, passively MR-guided by the artifact
of a 0.014-inch guidewire. After 4 weeks the rabbits were randomized into t
wo groups: group A (n = 8) underwent right-sided PTRA for treatment of RAS,
group B (n = 7) underwent left-sided PTRA. After another 4 weeks the rabbi
ts were killed to assess by histomorphometry recurrent stenosis and contral
ateral induction injury stenosis lesions. Each step was preceded by gadolin
ium-enhanced three-dimensional MR angiography, and the carter-to-aorta (C/A
) signal intensity ratio was calculated.
Results: RAS induction was successful in all cases. Fourteen arteries devel
oped restenosis and 13 only initial stenosis. MR-guided PTRAs were feasible
in 22 arteries (73%). For a successful catheterization of the ostium (20 a
rteries, 66%, success rate), 10-25 steps were required. Five to eight steps
were required for balloon localization and inflation for each PTRA. The re
stenosis effect was reflected by a 16% (12%-27%) decrease in C/A values on
MR angiograms (p < 0.05).
Conclusion: MR guidance and MR angiography represent a feasible, less invas
ive alternative for performing and assessing experimental PTRA in RAS.