Goldberg S N, Hahn P F, Tanabe K K, Mueller P R, Schima W, Athanasoulis C A, Compton C C, Solbiati L, Gazelle G S
Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA.
J Vasc Interv Radiol. 1998 Jan-Feb;9(1 Pt 1):101-11. doi: 10.1016/s1051-0443(98)70491-9.
To determine, by decreasing hepatic perfusion during radiofrequency (RF) ablation, whether perfusion-mediated tissue cooling can explain the reduced coagulation observed in in vivo studies compared to that seen with RF application in ex vivo tissue.
RF was applied in vivo with use of cooled-tip electrodes to normal porcine liver without (n = 8) and with balloon occlusion of the portal vein (n = 8), celiac artery (n = 3), or hepatic artery (n = 2), and to ex vivo calf liver (n = 10). In vivo trials of vasopressin (0.3-0.6 U/min) infusion during RF application with (n = 10) and without (n = 2) arterial balloon occlusion were also performed. Intraoperative RF was subsequently performed in seven patients with hepatic colorectal metastases with and without portal inflow occlusion. Remote thermometry was performed in four patients.
RF application (12 minutes) during portal venous occlusion produced larger areas of coagulation necrosis than RF with unaltered blood flow (2.9 cm +/- 0.1 vs 2.4 cm +/- 0.2 diameter; P < .01). With celiac and hepatic artery occlusion, coagulation diameter measured 2.7 cm +/- 0.2 and 2.5 cm +/- 0.1, respectively. Infusion of vasopressin without vascular occlusion reduced coagulation diameter to 1.1 cm. However, different methods of hepatic or celiac arterial balloon occlusion with simultaneous vasopressin infusion produced a mean 3.4 cm +/- 0.2 of necrosis. Coagulation in ex vivo liver was 2.9 cm +/- 0.1 in diameter. Clinical studies demonstrated greater coagulation diameter for metastases treated during portal inflow occlusion (4.0 cm +/- 1.3) than for tumors treated with normal blood flow (2.5 cm +/- 0.8; P < .05). Thermometry documented a 10 degrees C increase compared to baseline at 10 mm and 20 mm from the electrode after 5 minutes of portal inflow occlusion during constant RF application.
Perfusion-mediated tissue cooling reduces coagulation necrosis achievable with RF ablation. Reduction of blood flow during RF application increases coagulation in both an animal model and human liver metastases.
通过在射频（RF）消融期间减少肝脏灌注，确定灌注介导的组织冷却是否可以解释与离体组织中RF应用相比，在体内研究中观察到的凝固减少情况。
使用冷端电极在正常猪肝体内进行RF，其中未进行门静脉阻断（n = 8）、进行门静脉球囊阻断（n = 8）、腹腔动脉阻断（n = 3）或肝动脉阻断（n = 2），并在离体小牛肝脏（n = 10）上进行。还进行了在有（n = 10）和无（n = 2）动脉球囊阻断情况下，RF应用期间输注血管加压素（0.3 - 0.6 U/分钟）的体内试验。随后，对7例有和无门静脉流入阻断的肝结直肠癌转移患者进行了术中RF。对4例患者进行了远程温度测量。
门静脉阻断期间进行RF应用（12分钟）产生的凝固性坏死面积大于血流未改变时的RF应用（直径2.9 cm ± 0.1 vs 2.4 cm ± 0.2；P <.01）。腹腔动脉和肝动脉阻断时，凝固直径分别为2.7 cm ± 0.2和2.5 cm ± 0.1。未进行血管阻断时输注血管加压素可使凝固直径减小至1.1 cm。然而，同时进行血管加压素输注的不同肝动脉或腹腔动脉球囊阻断方法产生的平均坏死直径为3.4 cm ± 0.2。离体肝脏中的凝固直径为2.9 cm ± 0.1。临床研究表明，门静脉流入阻断期间治疗转移灶的凝固直径（4.0 cm ± 1.3）大于正常血流情况下治疗肿瘤的凝固直径（2.5 cm ± 0.8；P <.05）。温度测量记录显示，在持续RF应用期间，门静脉流入阻断5分钟后，距电极10 mm和20 mm处的温度比基线升高了10℃。
灌注介导的组织冷却减少了RF消融可实现的凝固性坏死。RF应用期间血流减少可增加动物模型和人类肝转移灶中的凝固。
