Feasibility Study on MR-Guided High-Intensity Focused Ultrasound Ablation of Sciatic Nerve in a Swine Model: Preliminary Results.

TitleFeasibility Study on MR-Guided High-Intensity Focused Ultrasound Ablation of Sciatic Nerve in a Swine Model: Preliminary Results.
Publication TypeJournal Article
Year of Publication2015
AuthorsKaye EA, Gutta NBabu, Monette S, Gulati A, Loh J, Srimathveeravalli G, Ezell PC, Erinjeri JP, Solomon SB, Maybody M
JournalCardiovasc Intervent Radiol
Volume38
Issue4
Pagination985-92
Date Published2015 Aug
ISSN1432-086X
Abstract

INTRODUCTION: Spastic patients often seek neurolysis, the permanent destruction of the sciatic nerve, for better pain management. MRI-guided high-intensity focused ultrasound (MRgHIFU) may serve as a noninvasive alternative to the prevailing, more intrusive techniques. This in vivo acute study is aimed at performing sciatic nerve neurolysis using a clinical MRgHIFU system.

METHODS: The HIFU ablation of sciatic nerves was performed in swine (n = 5) using a HIFU system integrated with a 3 T MRI scanner. Acute lesions were confirmed using T1-weighted contrast-enhanced (CE) MRI and histopathology using hematoxylin and eosin staining. The animals were euthanized immediately following post-ablation imaging.

RESULTS: Reddening and mild thickening of the nerve and pallor of the adjacent muscle were seen in all animals. The HIFU-treated sections of the nerves displayed nuclear pyknosis of Schwann cells, vascular hyperemia, perineural edema, hyalinization of the collagenous stroma of the nerve, myelin sheet swelling, and loss of axons. Ablations were visible on CE MRI. Non-perfused volume of the lesions (5.8-64.6 cc) linearly correlated with estimated lethal thermal dose volume (4.7-34.2 cc). Skin burn adjacent to the largest ablated zone was observed in the first animal. Bilateral treatment time ranged from 55 to 138 min, and preparation time required 2 h on average.

CONCLUSION: The acute pilot study in swine demonstrated the feasibility of a noninvasive neurolysis of the sciatic nerve using a clinical MRgHIFU system. Results revealed that acute HIFU nerve lesions were detectable on CE MRI, gross pathology, and histology.

DOI10.1007/s00270-015-1141-0
Alternate JournalCardiovasc Intervent Radiol
PubMed ID26040256
Grant ListP30 CA 008748 / CA / NCI NIH HHS / United States