TENS provides a beneficial adjunct for the treatment of cancer pain, especially when utilized as a goal-directed therapy.

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 cc – 64.6 cc) linearly correlated with estimated lethal thermal dose volume (4.7 cc – 34.2 cc). Skin burn adjacent to the largest ablated zone was observed in the first animal. Bilateral treatment time ranged from 55–138 minutes, and preparation time required 2 hours on average. Conclusion The acute pilot study in swine demonstrated the feasibility of a noninvasive neurolysis of the sciatic nerve by using a clinical MRgHIFU system. Results revealed that acute HIFU nerve lesions were detectable on CE MRI, gross pathology and histology.

High-intensity focused ultrasound may be used as a noninvasive neurolytic technique in swine. High-intensity focused ultrasound may have potential as a neuroablation technique for patients with chronic and cancer pain.

Initial results indicate that TENS provides an easy-to-use, inexpensive therapeutic tool that can be used an adjunct in the treatment of sarcoma-related cancer pain. Future studies consisting of a large, randomized trial will be necessary to validate the efficacy of TENS in this patient population.

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