Document Detail

Non-invasive pulsed cavitational ultrasound for fetal tissue ablation: feasibility study in a fetal sheep model.
MedLine Citation:
PMID:  21077151     Owner:  NLM     Status:  Publisher    
OBJECTIVE: Currently available fetal intervention techniques rely on invasive procedures that carry inherent risks. A non-invasive technique for fetal intervention could potentially reduce risks of fetal and obstetric complications. Pulsed cavitational ultrasound therapy (histotripsy) is an ablation technique that mechanically fractionates tissue at the focal region using extracorporeal ultrasound. In this study we investigated the feasibility of using histotripsy as a non-invasive approach to fetal intervention in a sheep model. METHODS: The experiments involved 11 gravid sheep, 102-129 days into gestation. Fetal kidney, liver, lung and heart were exposed to ultrasound pulses (<10 µs) delivered by an external 1 MHz focused ultrasound transducer at 0.2-1 kHz pulse repetition rate and 10-16 MPa peak negative pressure. Procedures were monitored and guided by real time ultrasound imaging. Treated organs were examined by gross and histological inspection for location and degree of tissue injury. RESULTS: Hyperechoic, cavitating bubble clouds were successfully generated in 19/31 (61%) treatment attempts in 27 fetal organs beneath up to 8 cm of overlying tissue and fetal bones. Morphological and histological assessment confirmed lesion locations and sizes corresponding to regions where cavitation was monitored, with no lesions found when cavitation was absent. Inability to generate cavitation was primarily associated with increased depth to target and obstructing structures such as fetal limbs. CONCLUSION: Extracorporeal histotripsy therapy successfully created targeted lesions in fetal sheep organs without significant damage to overlying structures. With further improvements, histotripsy may evolve into a viable technique for non-invasive fetal intervention procedures. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Yohan Kim; Sarah K Gelehrter; Carlen G Fifer; Jimmy C Lu; Gabe E Owens; Deborah R Berman; Jennifer Williams; J Erby Wilkinson; Kimberly A Ives; Zhen Xu
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2010-11-12
Journal Detail:
Title:  Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology     Volume:  -     ISSN:  1469-0705     ISO Abbreviation:  Ultrasound Obstet Gynecol     Publication Date:  2010 Nov 
Date Detail:
Created Date:  2010-11-15     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9108340     Medline TA:  Ultrasound Obstet Gynecol     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Department of Biomedical Engineering, University of Michigan, Ann Arbor MI, USA.
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