Johnson Alexander, Brace Christopher
Department of Biomedical Engineering and Department of Radiology, University of Wisconsin , Madison, Wisconsin , USA.
Int J Hyperthermia. 2015;31(5):551-9. doi: 10.3109/02656736.2015.1037799. Epub 2015 May 11.
Interventional oncology procedures such as thermal ablation are becoming widely used for many tumours in the liver, kidney and lung. Thermal ablation refers to the focal destruction of tissue by generating cytotoxic temperatures in the treatment zone. Hydrodissection - separating tissues with fluids - protects healthy tissues adjacent to the ablation treatment zone to improve procedural safety, and facilitate more aggressive power application or applicator placement. However, fluids such as normal saline and 5% dextrose in water (D5W) can migrate into the peritoneum, reducing their protective efficacy. As an alternative, a thermo-gelable poloxamer 407 (P407) solution has been recently developed to facilitate hydrodissection procedures. We hypothesise that the P407 gel material does not provide convective heat dissipation from the ablation site, and therefore may alter the heat transfer dynamics compared to liquid materials during hydrodissection-assisted thermal ablation. The purpose of this study was to investigate the heat dissipation mechanics within D5W, liquid P407 and gel P407 hydrodissection barriers. Overall it was shown that the gel P407 dissipated heat primarily through conduction, whereas the liquid P407 and D5W dissipated heat through convection. Furthermore, the rate of temperature change within the gel P407 was greater than liquid P407 and D5W. Testing to evaluate the in vivo efficacy of the fluids with different modes of heat dissipation seems warranted for further study.
诸如热消融之类的介入肿瘤学程序正被广泛应用于肝脏、肾脏和肺部的多种肿瘤治疗。热消融是指通过在治疗区域产生细胞毒性温度来对组织进行局部破坏。水分离法——用液体分离组织——可保护消融治疗区域附近的健康组织，以提高手术安全性，并便于更积极地施加能量或放置施源器。然而，诸如生理盐水和5%葡萄糖水溶液（D5W）等液体可能会渗入腹膜，降低其保护效果。作为一种替代方法，一种可热凝胶化的泊洛沙姆407（P407）溶液最近已被开发出来，以促进水分离程序。我们假设P407凝胶材料不会从消融部位提供对流散热，因此与水分离辅助热消融过程中的液体材料相比，可能会改变热传递动力学。本研究的目的是研究D5W、液体P407和凝胶P407水分离屏障内的散热机制。总体而言，结果表明凝胶P407主要通过传导散热，而液体P407和D5W通过对流散热。此外，凝胶P407内的温度变化速率大于液体P407和D5W。通过测试来评估具有不同散热模式的液体在体内的疗效似乎值得进一步研究。
