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Dan Leotta

Senior Engineer

Email

dfleotta@apl.washington.edu

Phone

206-616-6787

Education

B.S. Bioengineering, Syracuse University, 1982

M.S. Electrical Engineering, Massachusetts Institute of Technology, 1985

Ph.D. Bioengineering, University of Washington, 1998

Publications

2000-present and while at APL-UW

Sonographic features of abscess maturation in a porcine model

Lotta, D.F., M. Bruce, Y.-N. Wang, J. Kucewicz, T.K. Khokhlova, K. Chan, W. Monsky, and T.J. Matula, "Sonographic features of abscess maturation in a porcine model," Ultrasound Med. Biol., 47, 1920-1930, doi:10.1016/j.ultrasmedbio.2021.03.011, 2021.

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1 Jul 2021

Abscesses are walled-off collections of infected fluids that often develop as complications in the setting of surgery and trauma. Treatment is usually limited to percutaneous catheterization with a course of antibiotics. As an alternative to current treatment strategies, a histotripsy approach was developed and tested in a novel porcine animal model. The goal of this article is to use advanced ultrasound imaging modes to extract sonographic features associated with the progression of abscess development in a porcine model. Intramuscular or subcutaneous injections of a bi-microbial bacteria mixture plus dextran particles as an irritant led to identifiable abscesses over a 2 to 3 wk period. Selected abscesses were imaged at least weekly with B-mode, 3-D B-mode, shear-wave elastography and plane-wave Doppler imaging. Mature abscesses were characterized by a well-defined core of varying echogenicity surrounded by a hypoechoic capsule that was highly vascularized on Doppler imaging. 3-D imaging demonstrated the natural history of abscess morphology, with the abscess becoming less complex in shape and increasing in volume. Furthermore, shear-wave elastography demonstrated variations in stiffness as phlegmon becomes abscess and then liquefies, over time. These ultrasound features potentially provide biomarkers to aid in selection of treatment strategies for abscesses.

Treating porcine abscesses with histotripsy: A pilot study

Matula, T.J., Y.-N. Wang, T. Khokhlova, D.F. Leotta, J. Kucewicz, A.A. Brayman, M. Bruce, A.D. Maxwell, B.E. MacConaghy, G. Thomas, V.P. Chernikov, S.V. Buravkov, V.A. Khokhlova, K. Richmond, K. Chan, W. Monsky, "Treating porcine abscesses with histotripsy: A pilot study," Ultrasound Med. Biol., 47, 603-619, doi:10.1016/j.ultrasmedbio.2020.10.011, 2021.

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1 Mar 2021

Infected abscesses are walled-off collections of pus and bacteria. They are a common sequela of complications in the setting of surgery, trauma, systemic infections and other disease states. Current treatment is typically limited to antibiotics with long-term catheter drainage, or surgical washout when inaccessible to percutaneous drainage or unresponsive to initial care efforts. Antibiotic resistance is also a growing concern. Although bacteria can develop drug resistance, they remain susceptible to thermal and mechanical damage. In particular, short pulses of focused ultrasound (i.e., histotripsy) generate mechanical damage through localized cavitation, representing a potential new paradigm for treating abscesses non-invasively, without the need for long-term catheterization and antibiotics. In this pilot study, boiling and cavitation histotripsy treatments were applied to subcutaneous and intramuscular abscesses developed in a novel porcine model. Ultrasound imaging was used to evaluate abscess maturity for treatment monitoring and assessment of post-treatment outcomes. Disinfection was quantified by counting bacteria colonies from samples aspirated before and after treatment. Histopathological evaluation of the abscesses was performed to identify changes resulting from histotripsy treatment and potential collateral damage. Cavitation histotripsy was more successful in reducing the bacterial load while having a smaller treatment volume compared with boiling histotripsy. The results of this pilot study suggest focused ultrasound may lead to a technology for in situ treatment of acoustically accessible abscesses.

Histotripsy treatment of abscesses

Matula, T.J., Y.-N. Wang, T. Khokhlova, D.F. Leotta, J. Kucewicz, A.A. Brayman, M. Bruce, A.D. Maxwell, B.E. MacConaghy, G. Thomas, K. Richmond, K. Chan, and W. Monsky, "Histotripsy treatment of abscesses," in Proc., IEEE International Ultrasonics Symposium, 7-11 September, Las Vegas, NV, doi:10.1109/IUS46767.2020.9251683 (IEEE, 2020).

More Info

7 Sep 2020

Abscesses are walled-off collections of infected fluids containing pus and bacteria. They are often treated with percutaneous drainage in which a drainage catheter may be sutured in place for up to several weeks. Complications such as clogged drains or secondary infections require rehospitalization and wound management. Bacteria are susceptible to mechanical damage, and thus we hypothesize that histotripsy may be a potential new paradigm for treating abscesses noninvasively, without the need for long term catheterization and antibiotics. We developed a porcine animal model that recapitulates some of the features of human abscesses (including size and loculations). Boiling and cavitation histotripsy treatments were applied to subcutaneous and intramuscular abscesses in this porcine model. Ultrasound imaging was used to evaluate abscess maturity, for treatment monitoring and assessment of post-treatment outcomes. Disinfection was quantified by counting bacteria colonies from samples aspirated before and after treatment. Histopathological evaluation of the abscesses was performed to identify changes resulting from histotripsy treatment and potential collateral damage. The results of this pilot study suggest focused ultrasound may lead to a technology for in situ treatment of acoustically accessible abscesses.

More Publications

Inventions

Vascular Velocity Waveform Analysis from 2D Color Doppler Images

Record of Invention Number: 49097

Dan Leotta

Disclosure

26 Oct 2020

Device and Method to Break Urinary Stones in Pets

Record of Invention Number: 48640

Mike Bailey, Dan Leotta, Elizabeth Lynch, Brian MacConaghy, Adam Maxwell

Disclosure

28 May 2019

Easy 3D Ultrasound Imaging and Volume Quantification

Record of Invention Number: 48367

Mike Bailey, Bryan Cunitz, Dan Leotta

Disclosure

28 May 2019

More Inventions

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
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