Precision Targeted Ablation of Fine Neurovascular Structures In Vivo Using Dual-mode Ultrasound Arrays

Abstract

carotid bodies (cBs) are chemoreceptors that monitor and register changes in the blood, including the levels of oxygen, carbon dioxide, and pH, and regulate breathing. enhanced activity of cBs was shown to correlate with a significant elevation in the blood pressure of patients with hypertension. CB removal or denervation were previously shown to reduce hypertension. Here we demonstrate the feasibility of a dual-mode ultrasound array (DMUA) system to safely ablate the cB in vivo in a spontaneously hypertensive rat (SHR) model of hypertension. DMUA imaging was used for guiding and monitoring focused ultrasound (FUS) energy delivered to the target region. In particular, 3D imaging was used to identify the carotid bifurcation for targeting the cBs. intermittent, high frame rate imaging during image-guided fUS (igfUS) delivery was used for monitoring the lesion formation. DMUA imaging provided feedback for closed-loop control (cLc) of the lesion formation process to avoid overexposure. The procedure was tolerated well in over 100 SHR and normotensive rats that received unilateral and bilateral treatments. the measured mean arterial pressure (MAp) exhibited measurable deviation from baseline 2-4 weeks post IgFUS treatment. The results suggest that the direct unilateral FUS treatment of the CB might be sufficient to reduce the blood pressure in hypertensive rats and justify further investigation in large animals and eventually in human patients.

Safety and feasibility of arterial wall targeting with robot-assisted high intensity focused ultrasound: a preclinical study

“…A closed-loop control (CLC) algorithm was designed to modulate the HIFU intensity for each burst based on echogenicity changes due to the application of HIFU on a burst-byburst basis during the HIFU shot. The algorithm is described in detail by Aravalli et al [34]. Briefly, a HIFU shot is delivered over a user-specified exposure duration (e.g., 1 s) in bursts of 5 millisecond duration with a PRF of 100 Hz.…”

Safety and feasibility study of non-invasive robot-assisted high-intensity focused ultrasound therapy for the treatment of atherosclerotic plaques in the femoral artery: protocol for a pilot study

“…Dual-mode ultrasound arrays (DMUA) offers the possibility of simultaneous HIFU targeting and ultrasound (US) imaging, thereby allowing inherent registration between imaging and treatment location 19–21. HIFU/DMUA therapy can be used for transcutaneous noninvasive ablation of targets with submillimeter precision and accuracy 17 19–24. The pathophysiology of atherosclerosis suggests that atherosclerotic plaques may respond to HIFU/DMUA therapy 21.…”