In vitro thermal profile suitability assessment of acids and bases for thermochemical ablation: underlying principles.
J Vasc Interv Radiol
; 21(3): 381-5, 2010 Mar.
Article
em En
| MEDLINE
| ID: mdl-20097094
ABSTRACT
PURPOSE:
To measure and compare temperature changes in a recently developed gel phantom for thermochemical ablation as a function of reagent strength and concentration with several acids and bases. MATERIALS ANDMETHODS:
Aliquots (0.5-1 mL) of hydrochloric acid or acetic acid and sodium hydroxide or aqueous ammonia were injected for 5 seconds into a hydrophobic gel phantom. Stepwise increments in concentration were used to survey the temperature changes caused by these reactions. Injections were performed in triplicate, measured with a thermocouple probe, and plotted as functions of concentration and time.RESULTS:
Maximum temperatures were reached almost immediately in all cases, reaching 75 degrees C-110 degrees C at the higher concentrations. The highest temperatures were seen with hydrochloric acid and either base. More concentrated solutions of sodium hydroxide tended to mix incompletely, such that experiments at 9 M and higher were difficult to perform consistently.CONCLUSIONS:
Higher concentrations for any reagent resulted in higher temperatures. Stronger acid and base combinations resulted in higher temperatures versus weak acid and base combinations at the same concentration. Maximum temperatures obtained are in a range known to cause tissue coagulation, and all combinations tested therefore appeared suitable for further investigation in thermochemical ablation. Because of the loss of the reaction chamber shape at higher concentrations of stronger agents, the phantom does not allow complete characterization under these circumstances. Adequate mixing of reagents to maximize heating potential and avoid systemic exposure to unreacted acid and base must be addressed if the method is to be safely employed in tissues. In addition, understanding factors that control lesion shape in a more realistic tissue model will be critical.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ácidos
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Termografia
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Técnicas de Ablação
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Hipertermia Induzida
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Modelos Químicos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article