Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
HPB (Oxford). 2007;9(5):357-62. doi: 10.1080/13651820701646222.
Thermal ablative techniques have gained increasing popularity in recent years as safe and effective options for patients with unresectable solid malignancies. Microwave ablation has emerged as a relatively new technique with the promise of larger and faster burns without some of the limitations of radiofrequency ablation (RFA). Here we study a new microwave ablation device in a living porcine model using gross, histologic, and radiographic analysis.
The size and shape of ablated lesions were assessed using six pigs in a non-survival study. Liver tissue was ablated using 2, 4, and 8 min burns, in both peripheral and central locations, with and without vascular inflow occlusion. To characterize the post-ablation appearance, three additional pigs underwent several 4 min ablations each followed by serial computed tomography (CT) imaging at 7, 14, and 28 days postoperatively.
The 2 and 4 min ablations resulted in lesions that were similar in size, 33.5 cm(3) and 37.5 cm(3), respectively. Ablations lasting 8 min produced lesions that were significantly larger, 92.0 cm(3) on average. Proximity to hepatic vasculature and inflow occlusion did not significantly change lesion size or shape. In follow-up studies, CT imaging showed a gradual reduction in lesion volume over 28 days to 25-50% of the original volume.
Microwave ablation with a novel device results in consistently sized and shaped lesions. Importantly, we did not observe any significant heat-sink effect using this device, a major difference from RFA techniques. This system offers a viable alternative for creating fast, large ablation volumes for treatment in liver cancer.
近年来，作为无法切除的实体恶性肿瘤患者的安全有效治疗选择，热消融技术越来越受欢迎。微波消融作为一种相对较新的技术，具有更大和更快的消融区域而没有射频消融（RFA）的一些局限性的优势。在这里，我们使用活体猪模型通过大体标本、组织学和影像学分析来研究一种新型微波消融设备。
在非生存研究中，使用 6 头猪评估消融病变的大小和形状。使用 2、4 和 8 分钟的消融，在周围和中央位置，分别在有和没有血管流入闭塞的情况下进行肝组织消融。为了描述消融后的外观，另外 3 头猪接受了多次 4 分钟的消融，每次消融后分别在术后 7、14 和 28 天进行连续 CT 成像。
2 分钟和 4 分钟的消融导致的病变大小相似，分别为 33.5cm3和 37.5cm3。持续 8 分钟的消融产生的病变明显更大，平均为 92.0cm3。靠近肝血管和流入闭塞并不会显著改变病变的大小或形状。在后续研究中，CT 成像显示，消融病变体积在 28 天内逐渐减少至原始体积的 25-50%。
使用新型设备进行微波消融可产生一致大小和形状的病变。重要的是，我们没有观察到使用该设备存在任何明显的热沉效应，这是与 RFA 技术的主要区别。该系统为肝癌的快速、大体积消融治疗提供了一种可行的替代方案。
