Document Detail


A hydrophobic gel phantom for study of thermochemical ablation: initial results using a weak acid and weak base.
MedLine Citation:
PMID:  19699659     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: To develop a model for study of exothermic chemical reactions potentially useful for tissue ablation. MATERIALS AND METHODS: Seven gelatins ranging from 0.5% to 30% wt/vol with and without 15% or 30% caps and several commercial gels were evaluated. Baseline temperature measurements were taken. Acetic acid and ammonium hydroxide were sequentially injected over periods of 10-15 seconds in 1-mL aliquots, forming a discrete aqueous reaction chamber. Congo red pH indicator was included to assess the reaction. A thermocouple allowed data collection at completion of injection and every 15 seconds for 5 minutes. Injections were performed in triplicate, and average temperatures for each time point were reported. RESULTS: Gelatins fractured or refluxed even at the lowest concentrations tested. Most commercial gels proved too viscous and likewise led to reflux along the needle tract. A mineral oil-based gel was selected because of its ability to form a chamber without reflux or fracture and its clear colorless character, hydrophobic nature, chemical stability, viscosity, specific gravity, and cost. Temperatures during the first 60 seconds of the neutralization reaction showed an immediate increase that correlated well with concentration. CONCLUSIONS: The oil gel phantom is a safe, useful, readily available, inexpensive model to study mixing behaviors and maximum heating potentials for reactions that may prove useful in thermochemical tissue ablation for oncologic interventions. Measurable temperature changes occurred even at the lowest concentrations, and higher concentrations produced a greater release of heat energy.
Authors:
Andrew J Misselt; Theresa L Edelman; Jeung H Choi; John C Bischof; Erik N K Cressman
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Publication Detail:
Type:  Comparative Study; Evaluation Studies; Journal Article     Date:  2009-08-21
Journal Detail:
Title:  Journal of vascular and interventional radiology : JVIR     Volume:  20     ISSN:  1535-7732     ISO Abbreviation:  J Vasc Interv Radiol     Publication Date:  2009 Oct 
Date Detail:
Created Date:  2009-10-05     Completed Date:  2010-01-04     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9203369     Medline TA:  J Vasc Interv Radiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1352-8     Citation Subset:  IM    
Affiliation:
Department of Radiology, University of Minnesota Medical Center, Minneapolis, MN 55455, USA.
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MeSH Terms
Descriptor/Qualifier:
Ablation Techniques / methods*
Gels / chemistry*,  therapeutic use
Hydrogen-Ion Concentration
Hydrophobicity
Hyperthermia, Induced / methods*
Materials Testing
Chemical
Reg. No./Substance:
0/Gels

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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