# Photoacoustic-imaging-guided intravascular sonothrombolysis

> **NIH NIH R21** · NORTH CAROLINA STATE UNIVERSITY RALEIGH · 2020 · $182,356

## Abstract

Abstract: Deep vein thrombosis (DVT) induced pulmonary embolism (PE) causes more than 0.1
million deaths annually in the US alone. Recent innovative treatment techniques for thrombolysis,
such as pharmacological dissolution or fibrinolysis and mechanical fragmentation, have showed
progressive results, yet still suffer from severe limitations such as low thrombolysis efficiency and
long treatment times, frequent bleeding complications, high failure rate, vein injury associated
with severe regional dysfunction, recurrence, and the relatively large particle size of residual clot
debris which can result in distal embolism. This has led to great interest in sonothrombolysis, the
use of focused ultrasound to disrupt clots, yet current commercial sonothrombolysis systems (e.g.
EKOS) are still limited by long treatment times and peripheral tissue damage due to heating and
excessive acoustic exposure. More recently, our group and others have demonstrated several
advances which promise to improve the performance (significantly reduced treatment time) and
safety of thrombolysis using a microbubble-mediated laser ultrasound technology. We
hypothesize that the development of a new approach for sonothrombolysis combining laser
ultrasound, photoacoustic imaging guidance as well as cavitation-enhancing agents can
substantially improve the efficacy, safety, and impact of intravascular sonothrombolysis. In this
project, we develop innovative technologies from our collaborative group, each of which has
shown notable advantages over current technology, and we hypothesize that together they can
overcome challenges in the aforementioned embolism treatments. Specifically, a 4-French
forward firing fiber optic ultrasound (FOUS) catheter will be integrated with a photoacoustic
imaging system and a micro-tube for delivery of microbubbles and lytic agent (tissue-type
plasminogen activator or t-PA), to achieve forward firing intravascular sonothrombolysis. The
combination of microbubbles and broadband acoustic waves from FOUS is expected to achieve
high lytic rate. Furthermore, our forward-firing FOUS together with photoacoustic imaging will
enable ultrasound image guidance, reducing the need for fluoroscopy and improving procedure
safety. The FOUS catheter will be designed, prototyped and characterized, followed by in-vitro
and ex-vivo thrombolysis tests. Innovation comes from the forward-firing laser generated focused
ultrasound (LGFU) approach and catheter-based photoacoustic image guidance. This approach
will also reduce the dose of lytic agent, minimize physical contact with the target clot, and reduce
acoustic exposure of the surrounding tissues. The proposed FOUS catheter technology will
provide a new tool for accurate, fast, and safe DVT treatment.

## Key facts

- **NIH application ID:** 9930595
- **Project number:** 5R21EB027304-02
- **Recipient organization:** NORTH CAROLINA STATE UNIVERSITY RALEIGH
- **Principal Investigator:** Xiaoning Jiang
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $182,356
- **Award type:** 5
- **Project period:** 2019-06-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9930595

## Citation

> US National Institutes of Health, RePORTER application 9930595, Photoacoustic-imaging-guided intravascular sonothrombolysis (5R21EB027304-02). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/9930595. Licensed CC0.

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