Noninvasive therapeutic ultrasound to increase perfusion in chronic limb-threatening ischemia: An early feasibility study.

Publication Title

Vascular medicine (London, England)

Document Type

Article

Publication Date

2-1-2025

Keywords

california; psjh; Humans; Feasibility Studies; Male; Female; Aged; Pilot Projects; Peripheral Arterial Disease; Middle Aged; Ischemia; Quality of Life; Treatment Outcome; Regional Blood Flow; Ultrasonic Therapy; Time Factors; Laser-Doppler Flowmetry; Chronic Disease; Aged, 80 and over; Blood Gas Monitoring, Transcutaneous; Surveys and Questionnaires; Recovery of Function; Transducers

Abstract

Background: Preclinical studies have demonstrated that therapeutic ultrasound (TUS) increases perfusion in peripheral artery disease (PAD). This pilot study assessed the safety and effectiveness of a noninvasive TUS device in patients with advanced PAD.

Methods: A phased array of TUS transducers was fabricated on a wearable sleeve, designed to sonicate the posterior and anterior tibial arteries (and their collaterals) at the calf level. Twelve patients with PAD (Rutherford classes 3-5) were enrolled in a single-arm study in which they underwent 30-40 daily 90-minute TUS sessions to the diseased limb. Changes in pedal flow and tissue oxygenation (StO2) were measured by laser speckle and spatial frequency domain imaging, respectively. A subset of five patients underwent evaluation by laser Doppler, transcutaneous oximetry (TcPO2), and quality of life questionnaires (Vascular Quality of Life Questionnaire [VascuQoL] and the Walking Impairment Questionnaire [WIQ]).

Results: Eleven out of 12 enrolled patients completed the study. During 90-minute TUS sessions pedal flow improved by 180% (p < 0.001) on laser speckle imaging, and 18% (p = 0.12) on laser Doppler. Tissue oxygenation improved by 18% (p = 0.43) on TcPO2 and by 6% (p = 0.097) on StO2. After all sessions, tissue oxygenation improved by 17% (p = 0.020) on StO2, without significant changes in laser Doppler (+39%, p = 0.41) or TcPO2 (-3%, p = 0.70), which was largely in the normal range (56 ± 15 mmHg) at baseline. VascuQoL improved by 2.4 points (14%, p = 0.080) and WIQ improved by 8.2 points (11%, p = 0.053).

Conclusions: TUS for patients with symptomatic PAD was safe and well tolerated. Most metrics of tissue perfusion and oxygenation improved, but future sham-controlled studies are needed and planned.

Area of Special Interest

Cardiovascular (Heart)

Specialty/Research Institute

Cardiology

DOI

10.1177/1358863X241305093

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