Effects of Ablation (Radio Frequency, Cryo, Microwave) on Physiologic Properties of the Human Vastus Lateralis

Objective: Ablative treatments can sometimes cause collateral injury to surrounding muscular tissue, with important clinical implications. In this study, we investigated the changes in muscle physiology of the human vastus lateralis when exposed to three different ablation modalities: radiofrequency ablation, cryoablation, and microwave ablation. Methods: We obtained fresh vastus lateralis tissue biopsy specimens from nine patients (age range: 29-73 years) who were undergoing in vitro contracture testing for malignant hyperthermia. Using leftover waste tissue, we prepared 46 muscle bundles that were utilized in tissue baths before and after ablation. Results: After ablation with all the three modalities, we noted dose-dependent sustained reductions in peak force (strength of contraction), as well as transient increases in baseline force (resting muscle tension). But, over the subsequent 3-h recovery period, peak force improved and the baseline force consistently recovered to below its preablation levels. Conclusion: The novel in vitro methodologies we developed to investigate changes in muscle physiology after ablation can be used to study a spectrum of ablation modalities and also to make head-to-head comparisons of different ablation modalities. Significance: As the role of ablative treatments continues to expand, our findings provide unique insights into the resulting changes in muscle physiology. These insights could enhance the safety and efficacy of ablations and help individuals design and develop novel medical devices.