TY - JOUR
T1 - Renal sympathetic denervation using MR-guided high-intensity focused ultrasound in a porcine model
AU - Koopmann, Matthias
AU - Shea, Jill
AU - Kholmovski, Eugene
AU - de Bever, Joshua
AU - Minalga, Emilee
AU - Holbrook, Matthew
AU - Merrill, Robb
AU - Rock Hadley, J.
AU - Owan, Theophilus
AU - Salama, Mohamed E.
AU - Marrouche, Nassir F.
AU - Payne, Allison
N1 - Funding Information:
The authors are grateful for animal expertise of Jose Reyes and Orvelin Roman. This project was funded by the Joe W. & Dorothy Dorsett Brown Foundation and Arapeen Medical, Inc. Matthias Koopmann is supported by the German Heart Foundation (deutsche Herzstiftung e.V.).
Publisher Copyright:
© 2016 Koopmann et al.
PY - 2016
Y1 - 2016
N2 - Background: Initial catheter-based renal sympathetic denervation (RSD) studies demonstrated promising results in showing a significant reduction of blood pressure, while recent data were less successful. As an alternative approach, the objective of this study was to evaluate the feasibility of using magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) to perform RSD in a porcine model. Methods: An intravascular fiber optic temperature probe was used to confirm energy delivery during MRgHIFU. This technique was evaluated both in a vascular phantom and in a normotensive pig model. Five animals underwent unilateral RSD using MRgHIFU, and both safety and efficacy were assessed. MRI was used to evaluate the acoustic window, target sonications, monitor the near-field treatment region using MR thermometry imaging, and assess the status of tissues post-procedure. An intravascular fiber optic temperature probe verified energy delivery. Animals were sacrificed 6 to 9 days post-treatment, and pathological analysis was performed. The norepinephrine present in the kidney medulla was assessed post-mortem. Results: All animals tolerated the procedure well with no observed complications. The fiber optic temperature probe placed in the target renal artery confirmed energy delivery during MRgHIFU, measuring larger temperature rises when the MRgHIFU beam location was focused closer to the tip of the probe. Following ablation, a significant reduction (p = 0.04) of cross-sectional area of nerve bundles between the treated and untreated renal arteries was observed in all of the animals with treated nerves presenting increased cellular infiltrate and fibrosis. A reduction of norepinephrine (p = 0.14) in the kidney medulla tissue was also observed. There was no indication of tissue damage in arterial walls. Conclusions: Performing renal denervation non-invasively with MRgHIFU was shown to be both safe and effective as determined by norepinephrine levels in a porcine model. This approach may be a promising alternative to catheter-based strategies.
AB - Background: Initial catheter-based renal sympathetic denervation (RSD) studies demonstrated promising results in showing a significant reduction of blood pressure, while recent data were less successful. As an alternative approach, the objective of this study was to evaluate the feasibility of using magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) to perform RSD in a porcine model. Methods: An intravascular fiber optic temperature probe was used to confirm energy delivery during MRgHIFU. This technique was evaluated both in a vascular phantom and in a normotensive pig model. Five animals underwent unilateral RSD using MRgHIFU, and both safety and efficacy were assessed. MRI was used to evaluate the acoustic window, target sonications, monitor the near-field treatment region using MR thermometry imaging, and assess the status of tissues post-procedure. An intravascular fiber optic temperature probe verified energy delivery. Animals were sacrificed 6 to 9 days post-treatment, and pathological analysis was performed. The norepinephrine present in the kidney medulla was assessed post-mortem. Results: All animals tolerated the procedure well with no observed complications. The fiber optic temperature probe placed in the target renal artery confirmed energy delivery during MRgHIFU, measuring larger temperature rises when the MRgHIFU beam location was focused closer to the tip of the probe. Following ablation, a significant reduction (p = 0.04) of cross-sectional area of nerve bundles between the treated and untreated renal arteries was observed in all of the animals with treated nerves presenting increased cellular infiltrate and fibrosis. A reduction of norepinephrine (p = 0.14) in the kidney medulla tissue was also observed. There was no indication of tissue damage in arterial walls. Conclusions: Performing renal denervation non-invasively with MRgHIFU was shown to be both safe and effective as determined by norepinephrine levels in a porcine model. This approach may be a promising alternative to catheter-based strategies.
KW - High-intensity focused ultrasound
KW - MRI
KW - Renal sympathetic denervation
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U2 - 10.1186/s40349-016-0048-9
DO - 10.1186/s40349-016-0048-9
M3 - Article
AN - SCOPUS:85010424167
SN - 2050-5736
VL - 4
JO - Journal of Therapeutic Ultrasound
JF - Journal of Therapeutic Ultrasound
IS - 1
M1 - 3
ER -