Augmentation of Limb Perfusion With Contrast Ultrasound

Purpose

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.

Condition

  • Peripheral Arterial Disease

Eligibility

Eligible Ages
Between 19 Years and 99 Years
Eligible Sex
All
Accepts Healthy Volunteers
Yes

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).

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Non-Randomized
Intervention Model
Single Group Assignment
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Healthy subjects
Low-power contrast ultrasound perfusion imaging and measurement of ABI and TBI will be performed before and after a 15 min high-power ultrasound cavitation therapy with intermittent ultrasound and intravenous infusion of microbubbles.
  • Device: Ultrasound
    Ultrasound exposure of Definity microbubbles infused over 10 min. Ultrasound administered at 1.3 MHz, mechanical index of 1.3, and pulsing interval of 10 s.
    Other names:
    • Contrast ultrasound
Experimental
Peripheral Artery Disease
Low-power contrast ultrasound perfusion imaging and measurement of ABI and TBI will be performed before and after a 15 min high-power ultrasound cavitation therapy with intermittent ultrasound and intravenous infusion of microbubbles.
  • Device: Ultrasound
    Ultrasound exposure of Definity microbubbles infused over 10 min. Ultrasound administered at 1.3 MHz, mechanical index of 1.3, and pulsing interval of 10 s.
    Other names:
    • Contrast ultrasound

Recruiting Locations

OHSU
Portland, Oregon 97239
Contact:
Jonathan R Lindner, MD
503-494-8750
lindnerj@ohsu.edu

More Details

NCT ID
NCT03195556
Status
Recruiting
Sponsor
Oregon Health and Science University

Study Contact

Jonathan R Lindner, MD
5034943574
lindnerj@ohsu.edu