Department of Interventional Ultrasound, Chinese PLA General Hospital Fifth Medical Center, Beijing, 100853, China.
The Yuquan Campus, Zhejiang University, Hangzhou, Zhejiang, China.
Comput Methods Programs Biomed. 2024 Dec;257:108383. doi: 10.1016/j.cmpb.2024.108383. Epub 2024 Aug 23.
This study aimed to investigate the efficacy of a small-gauge microwave ablation antenna (MWA) with an enhanced cooling system (ECS) for generating more spherical ablation zones.
A comparison was made between two types of microwave ablation antennas, one with ECS and the other with a conventional cooling system (CCS). The finite element method was used to simulate in vivo ablation. Two types of antennas were used to create MWA zones for 5, 8, 10 min at 50, 60, and 80 W in ex vivo bovine livers (n = 6) and 5 min at 60 W in vivo porcine livers (n = 16). The overtreatment ratio, ablation aspect ratio, carbonization area, and other characteristcs of antennas were measured and compared using numerical simulation and gross pathologic examination.
In numerical simulation, the ECS antenna demonstrated a lower overtreatment ratio than the CCS antenna (1.38 vs 1.43 at 50 W 5 min, 1.19 vs 1.35 at 50 W 8 min, 1.13 vs 1.32 at 50 W 10 min, 1.28 vs 1.38 at 60 W 5 min, 1.14 vs 1.32 at 60 W 8 min, 1.10 vs 1.30 at 60 W 10 min). The experiments revealed that the ECS antenna generated ablation zones with a more significant aspect ratio (0.92 ± 0.03 vs 0.72 ± 0.01 at 50 W 5 min, 0.95 ± 0.02 vs 0.70 ± 0.01 at 50 W 8 min, 0.96 ± 0.01 vs 0.71 ± 0.04 at 50 W 10 min, 0.96 ± 0.01 vs 0.73 ± 0.02 at 60 W 5 min, 0.94 ± 0.03 vs 0.71 ± 0.03 at 60 W 8 min, 0.96 ± 0.02 vs 0.69 ± 0.04 at 60 W 10 min) and a smaller carbonization area (0.00 ± 0.00 cm vs 0.54 ± 0.06 cm at 50 W 5 min, 0.13 ± 0.03 cm vs 0.61 ± 0.09 cm at 50 W 8 min, 0.23 ± 0.05 cm vs 0.73 ± 0.05 m at 50 W 10 min, 0.00 ± 0.00 cm vs 1.59 ± 0.41 cm at 60 W 5 min, 0.23 ± 0.22 cm vs 2.11 ± 0.63 cm at 60 W 8 min, 0.57 ± 0.09 cm vs 2.55 ± 0.51 cm at 60 W 10 min). Intraoperative ultrasound images revealed a hypoechoic area instead of a hyperechoic area near the antenna. Hematoxylin-eosin staining of the dissected tissue revealed a correlation between the edge of the ablation zone and that of the hypoechoic area.
The ECS antenna can produce more spherical ablation zones with less charring and a clearer intraoperative ultrasound image of the ablation area than the CCS antenna.
本研究旨在探讨一种带有增强冷却系统（ECS）的小口径微波消融天线（MWA）生成更球形消融区的疗效。
比较了两种微波消融天线，一种带有 ECS，另一种带有常规冷却系统（CCS）。使用有限元法模拟体内消融。使用两种天线在离体牛肝中分别以 50、60 和 80 W 进行 5、8 和 10 分钟消融（n=6），以及在活体猪肝中以 60 W 进行 5 分钟消融（n=16）。使用数值模拟和大体病理检查比较了天线的过度治疗比、消融长宽比、碳化面积等特征。
数值模拟中，ECS 天线的过度治疗比低于 CCS 天线（50 W 5 分钟时为 1.38 比 1.43，50 W 8 分钟时为 1.19 比 1.35，50 W 10 分钟时为 1.13 比 1.32，60 W 5 分钟时为 1.28 比 1.38，60 W 8 分钟时为 1.14 比 1.32，60 W 10 分钟时为 1.10 比 1.30）。实验表明，ECS 天线产生的消融区具有更显著的长宽比（50 W 5 分钟时为 0.92±0.03 比 0.72±0.01，50 W 8 分钟时为 0.95±0.02 比 0.70±0.01，50 W 10 分钟时为 0.96±0.01 比 0.71±0.04，60 W 5 分钟时为 0.96±0.01 比 0.73±0.02，60 W 8 分钟时为 0.94±0.03 比 0.71±0.03，60 W 10 分钟时为 0.96±0.02 比 0.69±0.04），碳化面积较小（50 W 5 分钟时为 0.00±0.00 cm 比 0.54±0.06 cm，50 W 8 分钟时为 0.13±0.03 cm 比 0.61±0.09 cm，50 W 10 分钟时为 0.23±0.05 cm 比 0.73±0.05 cm，60 W 5 分钟时为 0.00±0.00 cm 比 1.59±0.41 cm，60 W 8 分钟时为 0.23±0.22 cm 比 2.11±0.63 cm，60 W 10 分钟时为 0.57±0.09 cm 比 2.55±0.51 cm）。术中超声图像显示天线附近呈现低回声区域而非高回声区域。解剖组织的苏木精-伊红染色显示消融区边缘与低回声区边缘之间存在相关性。
与 CCS 天线相比，ECS 天线可产生更球形的消融区，碳化更少，术中超声图像更清晰。
