Augmentation of Limb Perfusion With Contrast Ultrasound

N/ARecruitingNCT03195556

Oregon Health and Science University30 enrolled

Overview

Our laboratory has discovered that ultrasound (US) imaging together with clinically approved microbubble ultrasound contrast agents can augment limb tissue perfusion. These observations have been made in mice with and without peripheral artery disease (PAD), and also in humans where high power contrast enhanced ultrasound (CEU) was used to measure perfusion but was found also to augment perfusion by almost 2-fold. The latter human studies were performed with ultrasound protocols designed for perfusion imaging and not for flow augmentation. In this study, we will measure the degree to which limb perfusion is augmented with specific therapeutic CEU settings that are still within the FDA-approved limits with regards to US power and contrast dosing.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Peripheral Arterial Disease

Interventions

Eligibility

Sex: ALLMin age: 19 YearsMax age: 99 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Age ≥18 y.o. * For PAD subjects: known history of unilateral or bilateral PAD diagnosed by reduced ankle-brachial index or angiography and a Rutherford symptom class of 4-6. Exclusion Criteria: 1. Major medical illness other than PAD affecting the limb (muscle disease, blood diseases that influence flow or rheology, severe heart failure \[NYHA class IV or LVEF \<30%\]). 2. Pregnant or lactating females 3. Hypersensitivity to any ultrasound contrast agent 4. Known atrial septal defect or large right to left shunt. 5. Hemodynamic instability (hypotension with systolic BP \<90 mm Hg, need for vasopressors) 6. Evidence for ongoing myocardial ischemia 7. For normal controls, any known structural non-arrhythmic cardiovascular disease (coronary artery disease, heart failure, moderate or greater valve disease).

Outcomes

Primary Outcomes

Change in blood flow at 10 min

Change in blood flow in calf skeletal muscle

Time frame: 10 min post-therapeutic ultrasound cavitation.

Change in blood flow at 60 min