Experimental Research
Comparison of microwave thermosphere ablation and conventional microwave ablation in ex vivo bovine livers
Chu Wenying, Li Dan, Long Lei, Ding Jianmin, Zhou Yan, Jing Xiang
Published 2019-04-25
Cite as Chin J Ultrasonogr, 2019,28(4): 353-358. DOI: 10.3760/cma.j.issn.1004-4477.2019.04.014
Abstract
ObjectiveTo compare the effectiveness of microwave thermosphere ablation(MTA) and traditional microwave ablation(MWA) in ex vivo bovine livers, and to compare the degree of the heat sink effect in them.
MethodsThe non-vessel model and vessel model were established using fresh bovine livers. In non-vessel model(n=48), the same power-time settings were used in both MTA group and MWA group, which were 80 W 12 min, 90 W 10 min and 100 W 10 min, respectively. Long-axis diameter(Dl), short-axis diameter(Ds1, Ds2), roundness index(R) and the time of temperature rising to 60℃ at place of 10 mm from the needle were measured.In vessel model(n=144), different vessel diameters(3 mm, 5 mm, 10 mm) and flow rates (15 cm/s, 20 cm/s, 30 cm/s) were setted. The maximum radius(Rmax), total area of ablation zone(Sz), and the area difference (Sdiff) were analyzed, the temperatures adjacent to the vessel were monitored simultaneously.
ResultsIn non-vessel model, with the same power and time settings, the Dl of MTA group was significantly smaller than MWA group (P<0.01), however, there was no significant difference of Ds1 and Ds2 between the two groups(P>0.05). And MTA group created more spherical ablation zones, since the R of MTA group were more close to 1 (P<0.01). In MTA group, the time of temperature rising to 60 ℃ at place of 10 mm from the needle was slower than MWA group (P<0.01). In vessel model, the Sdiff of MTA group were hardly affected by the vessel diameters and flow rates(P>0.05), and there was also no statistical significance among different flow rates(P>0.05) in MWA group, but the Sdiff of MWA group was significantly affected by the vessel diameters(P<0.01). And the Sdiff of MTA group was significantly smaller than MWA group when the vessel diameter was 10 mm(P<0.05), while there was no statistical significance between the two groups when the vessel diameter was 3 mm or 5 mm(P>0.05).
ConclusionsCompared to MWA, MTA can produce sizable, regular and more spherical ablation lesions with the same power and time, meanwhile, it is less affected by the heat sink effect.
Key words:
Ultrasonography; Microwave ablation; Heat sink effect; Ex vivo
Contributor Information
Chu Wenying
The Third Central Clinical College of Tianjin Medical University, Tianjin 300170, China
Li Dan
The Third Central Clinical College of Tianjin Medical University, Tianjin 300170, China
Long Lei
The Third Central Clinical College of Tianjin Medical University, Tianjin 300170, China
Ding Jianmin
Department of Ultrasound, Third Central Hospital of Tianjin, Tianjin Institute of Hepatobiliary Disease, Tianjin Key Laboratory of Artificial Cell, Artifical Cell Engineering Technology Research Center of Public Health Ministry, Tianjin 300170, China
Zhou Yan
Department of Ultrasound, Third Central Hospital of Tianjin, Tianjin Institute of Hepatobiliary Disease, Tianjin Key Laboratory of Artificial Cell, Artifical Cell Engineering Technology Research Center of Public Health Ministry, Tianjin 300170, China
Jing Xiang
Department of Ultrasound, Third Central Hospital of Tianjin, Tianjin Institute of Hepatobiliary Disease, Tianjin Key Laboratory of Artificial Cell, Artifical Cell Engineering Technology Research Center of Public Health Ministry, Tianjin 300170, China
