Zhang Dedong, Xie Daolin, Wei Xiaoli, Zhang Dakun, Chen Min, Yu Xiaoling, Liang Ping
Department of Interventional Ultrasound, Chinese PLA General Hospital , Beijing .
Int J Hyperthermia. 2014 Mar;30(2):126-33. doi: 10.3109/02656736.2013.874048. Epub 2014 Feb 14.
Collateral thermal injury can occur as a serious complication of microwave ablation. This study aimed to assess the insulating effect of a thermosensitive, chitosan-based hydrogel during the percutaneous microwave ablation of liver tissue abutting the stomach.
Thermometry needles (R1-R4) were positioned at 5-mm intervals from a thermal source to measure in vitro the temperature differences due to the hydrogel (R1 closest to the thermal source). Subsequently, two groups of eight rabbits each were injected with 10 mL of hydrogel solution or 410 ± 95 mL of 5% saline between the liver and stomach wall. A control group of eight rabbits received no ablation protection measures. The livers were ablated with 40 W for 300 s in 24 ablation zones. The severity of thermal injury to the stomach wall was assessed histologically.
In vitro, the mean maximum temperature difference between the R1 and R2 thermometry needles was 31.3° ± 0.1 °C. When R1 was over 60 °C, the mean temperatures at R2, R3, and R4 were 29.8° ± 0.1 °C, 18.6 ± 0.3 °C, and 18.1° ± 0.1 °C, respectively. After ablation for 300 s, the maximum temperature at R2 was 48.7° ± 0.2 °C. None of the rabbits injected with gel showed any injury after ablation; however, the other two groups showed varying degrees of thermal injury.
The in situ gel protected the adjacent stomach wall from injury during percutaneous microwave ablation of liver tissue. Although the present technique appears promising, further studies are necessary prior to clinical application.
侧支热损伤可能作为微波消融的严重并发症出现。本研究旨在评估一种热敏性壳聚糖基水凝胶在经皮微波消融毗邻胃的肝组织过程中的隔热效果。
测温针（R1 - R4）以距热源5毫米的间隔放置，用于在体外测量由于水凝胶导致的温度差异（R1最靠近热源）。随后，两组各8只兔子分别在肝脏和胃壁之间注射10毫升水凝胶溶液或410±95毫升5%盐水。一组8只兔子的对照组未采取消融保护措施。在24个消融区域用40瓦功率对肝脏进行300秒的消融。通过组织学评估胃壁的热损伤严重程度。
在体外，R1和R2测温针之间的平均最大温度差为31.3°±0.1°C。当R1超过60°C时，R2、R3和R4处的平均温度分别为29.8°±0.1°C、18.6±0.3°C和18.1°±0.1°C。消融300秒后，R2处的最高温度为48.7°±0.2°C。注射凝胶的兔子在消融后均未出现任何损伤；然而，其他两组出现了不同程度的热损伤。
原位凝胶在经皮微波消融肝组织过程中保护了毗邻的胃壁免受损伤。尽管目前这项技术看起来很有前景，但在临床应用之前还需要进一步研究。
