Frericks Bernd B, Ritz Jörg P, Albrecht Thomas, Valdeig Steffi, Schenk Andrea, Wolf Karl-Jürgen, Lehmann Kai
Department of Radiology and Nuclear Medicine, Campus Benjamin Franklin-Charité, University Medicine Berlin, Berlin, Germany.
Invest Radiol. 2008 Apr;43(4):211-8. doi: 10.1097/RLI.0b013e31815daf36.
Aim of the study was to evaluate the precise influence of different intrahepatic vessels, vessel sizes, and distances from the applicator on volume and shape of hepatic laser ablation zones in an in vivo porcine model.
The study was approved by the institutional animal care and use committee. Eighteen computed tomography-guided Nd:YAG laser ablations were performed in the livers of 10 pigs at varying distances from hepatic veins and portal fields. After hepatectomy the livers were cut into 2-mm slices perpendicular to the laser applicator axes. For each ablation zone the maximum achievable (ideal) volume, the segmented (real) volume, the maximum radius, and the radius at the position of adjacent hepatic vessels were determined. The shapes of the ablation zones were evaluated qualitatively. Comparative statistics using the unpaired t test and a multiple linear regression analysis were performed.
Ideal and real ablation zone volumes differed by 27.3% (8.6 +/- 1.5 mL vs. 6.4 +/- 1.1 mL; P < 0.0001). Thirty-eight of 60 (63%) hepatic veins versus 28 of 31 (90%) portal veins within the central slices of the 18 ablation zones led to a reduction of the ablation zone's radius, depending on the distance between the vessel and the applicator and the vessel type. Portal fields revealed stronger effects than hepatic veins. The vessel diameter showed no independent effect (P > 0.05). When influencing, all hepatic veins showed a focal indentation whereas portal fields always showed broad flattening of the ablation zone.
Portal fields lead to more heat sink than hepatic veins. The effects decreased with the distance between vessel and applicator tip, but less so for portal fields. The 2 vessel types induced considerably different shape alterations of the ablation zones. These results were not dependent on vessel size. This should be considered in the planning of thermal tumor ablations.
本研究旨在评估在体内猪模型中，不同肝内血管、血管大小以及与消融器的距离对肝激光消融区体积和形状的精确影响。
本研究经机构动物护理和使用委员会批准。在10头猪的肝脏中，于距肝静脉和门静脉区域不同距离处进行了18次计算机断层扫描引导下的Nd:YAG激光消融。肝切除术后，将肝脏切成垂直于激光消融器轴的2毫米切片。对于每个消融区，确定其最大可实现（理想）体积、分割（实际）体积、最大半径以及相邻肝血管位置处的半径。对消融区的形状进行定性评估。采用不成对t检验和多元线性回归分析进行比较统计。
理想消融区体积与实际消融区体积相差27.3%（8.6±1.5毫升对6.4±1.1毫升；P<0.0001）。在18个消融区的中央切片中，60条肝静脉中的38条（63%）与31条门静脉中的28条（90%）导致消融区半径减小，这取决于血管与消融器之间的距离以及血管类型。门静脉区域的影响比肝静脉更强。血管直径未显示出独立影响（P>0.05）。当产生影响时，所有肝静脉均表现为局部凹陷，而门静脉区域总是使消融区出现广泛变平。
门静脉区域比肝静脉导致更多的热沉效应。这些效应随血管与消融器尖端之间的距离增加而减小，但门静脉区域减小的程度较小。这两种血管类型引起的消融区形状改变差异很大。这些结果与血管大小无关。在热肿瘤消融治疗计划中应考虑到这一点。
