Department of Radiology, University of California, Davis Medical Center, 4860 Y St, Suite 3100, Sacramento, CA 95817, USA.
Radiology. 2010 Aug;256(2):397-405. doi: 10.1148/radiol.09090662. Epub 2010 Jun 8.
To compare an algorithm of gradually ramped-up power to a full-power-level technique to determine which technical parameters maximized tissue coagulation by using a saline-perfused electrode.
Institutional review board approval was not necessary and animal committee approval was unnecessary because an ex vivo bovine liver model was used and the animals were not specifically killed for this study. This four-part experiment utilized multiple ablations of ex vivo bovine liver with a standard radiofrequency (RF) generator and an internally cooled needle. First, 10 RF ablations were performed at 20-60 W for 12 minutes. Second, ablation volumes obtained from an algorithm of eight ablations performed at 50 W were compared with those obtained from an algorithm of eight ablations that were gradually ramped-up to 50 W, until full impedance. Third, volumes obtained from 10 ablations performed at impedance control power levels were compared with those obtained from 10 ablations performed with a gradual ramp-up of power that started at 50 W, terminating at full impedance. Last, the third part was repeated, but with 11 ablations continuing past full impedance for 12 minutes each.
In the first part, maximum measurements of tissue coagulation seemed to plateau from 40 to 60 W. The second part produced significantly larger measurements of tissue coagulation than did the use of a constant power level of 50 W. The third and final parts produced larger measurements of tissue coagulation than did utilizing full power for 12 minutes. Larger measurements and volumes were obtained from repeat ablations after the generator reached impedance level than were obtained from ablations stopped at maximum impedance.
A gradual ramp-up of power and repeating ablations after power impedance level is reached are the two methods that increased tissue ablation in this ex vivo experiment.
比较逐渐升压功率算法与全功率水平技术，以确定哪种技术参数通过盐水灌注电极最大程度地实现组织凝固。
本研究无需机构审查委员会批准，也无需动物委员会批准，因为使用了离体牛肝模型，并且动物不是专门为此项研究而杀死的。这项四部分实验利用标准射频（RF）发生器和内部冷却针对离体牛肝进行了多次消融。首先，在 12 分钟内以 20-60 W 的功率进行 10 次 RF 消融。其次，比较在 50 W 下进行 8 次消融的算法获得的消融体积与逐渐升压至 50 W 直至达到全阻抗的 8 次消融算法获得的消融体积。第三，比较在阻抗控制功率水平下进行 10 次消融获得的体积与从 50 W 开始逐渐升压至全阻抗的 10 次消融获得的体积。最后，重复第三部分，但在全阻抗下进行 11 次消融，每次持续 12 分钟。
在第一部分中，组织凝固的最大测量值似乎在 40 到 60 W 之间趋于平稳。第二部分产生的组织凝固测量值明显大于使用 50 W 恒定功率水平的测量值。第三部分（也是最后一部分）产生的组织凝固测量值大于使用 12 分钟全功率的测量值。在发生器达到阻抗水平后进行重复消融会获得比在达到最大阻抗时停止消融更大的测量值和体积。
在这项离体实验中，逐渐升压功率和在达到功率阻抗水平后重复消融是增加组织消融的两种方法。
