MR-guided periarterial ethanol injection for renal sympathetic denervation: a feasibility study in pigs.
OBJECTIVE
To evaluate the feasibility and efficacy of image-guided periarterial ethanol injection as an alternative to transluminal radiofrequency ablation.


METHODS
Unilateral renal periarterial ethanol injection was performed under general anesthesia in 6 pigs with the contralateral kidney serving as control. All interventions were performed in an open 1.0 T MRI system under real-time multiplanar guidance. The injected volume was 5 ml (95 % ethanol labelled marked MR contrast medium) in 2 pigs and 10 ml in 4 pigs. Four weeks after treatment, the pigs underwent MRI including MRA and were killed. Norepinephrine (NE) concentration in the renal parenchyma served as a surrogate parameter to analyze the efficacy of sympathetic denervation. In addition, the renal artery and sympathetic nerves were examined histologically to identify evidence of vascular and neural injury.


RESULTS
In pigs treated with 10 ml ethanol, treatment resulted in neural degeneration. We found a significant reduction of NE concentration in the kidney parenchyma of 53 % (p < 0.02) compared with the untreated contralateral kidney. In pigs treated with 5 ml ethanol, no significant changes in histology or NE were observed. There was no evidence of renal arterial stenosis in MRI, macroscopy or histology in any pig.


CONCLUSIONS
MR-guided periarterial ethanol injection was feasible and efficient for renal sympathetic denervation in a swine model. This technique may be a promising alternative to the catheter-based approach in the treatment of resistant arterial hypertension.
Department of Radiology, Charité, Humboldt University, Charitéplatz 1, 10117 Berlin, Germany. florian.streitparth@charite.de
F
F
Streitparth
A
A
Walter
N
N
Stolzenburg
L
L
Heckmann
J
J
Breinl
J L
JL
Rinnenthal
A
A
Beck
M
M
De Bucourt
J
J
Schnorr
U
U
Bernhardt
B
B
Gebauer
B
B
Hamm
R W
RW
Günther
D000818:Animals; D000431:Ethanol / Q000494:pharmacology*; D005240:Feasibility Studies; D007668:Kidney / Q000187:drug effects / Q000294:innervation*; D053783:Magnetic Resonance Imaging, Interventional; D013552:Swine; D013562:Sympathectomy / Q000379:methods*
D000431:Ethanol