Yoneda K Y, Herth F, Spangler T, Raina S, Panescu D
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:5252-5258. doi: 10.1109/EMBC44109.2020.9176238.
This paper presents results from long-term survival study where healthy swine were ablated with a novel technology designed for treating early-stage non-small cell lung cancer using an endobronchial flexible catheter.Methods - The radiofrequency ablation (RFA) system has been presented previously and consisted of an ablation catheter, radiofrequency generator, irrigation pump for infusion of hypertonic saline (HS) and a laptop. The catheter carried an occlusion balloon, a 5 mm long RF electrode, with irrigation holes, and a 1 mm long electrode for bipolar impedance measurements. The outer diameter (OD) was 1.4 mm for compatibility with current bronchoscopes, navigation systems and radial EBUS. Nine swine were treated in this study with survival times of 1, 4 and 12 weeks (N=3 at each time point). In all animals, the treatment sites consisted of one location in the upper right lung (RUL) and another one in the lower right lung (RLL). CTs were taken pre-op, immediately post-op and at every 2 weeks post treatment. Ablation times ranged from 6 to 8 min and average applied power was 68 W (range 63 - 72 W).Results - At 1-week survival, large zones of necrotic tissue were observed in all respective 6 ablations. Ablation volumes had an average diameter of 3.2 cm at RUL locations and 3.8 cm in RLLs (likely due to longer RLL ablation durations). As time progressed, the necrotic tissue was gradually replaced with fibrotic tissue. At 4-week survival, the replacement was almost complete in all respective 3 animals. As a result, ablation volumes decreased to an average diameter of 1.3 cm at RUL locations and 2.3 cm in RLLs (likely due to longer RLL ablation durations). At 12-week survival, as the replacement process continued, histopathology revealed zones of residual necrotic tissue that were further reduced in size. Ablation zones had been resorbed and contracted by fibrous scar tissue. The average volume of the treatment effect decreased to 1.1 cm (RUL) and to 1.6 cm (RLL) in equivalent diameter. There were no complications in any of the nine animals.Conclusion - In healthy swine lungs, RFA with a 1.4-mm OD, radial-EBUS-sheath-compatible, endobronchial catheter was effective and safe. This system and therapeutic approach may be considered for further evaluation in minimally invasive treatment of tumorous lung nodules.
本文介绍了一项长期生存研究的结果，该研究使用一种专为治疗早期非小细胞肺癌设计的新技术，通过支气管内柔性导管对健康猪进行消融。方法——射频消融（RFA）系统此前已介绍过，由消融导管、射频发生器、用于输注高渗盐水（HS）的灌注泵和一台笔记本电脑组成。导管带有一个阻塞球囊、一个5毫米长的带灌注孔的射频电极以及一个用于双极阻抗测量的1毫米长电极。外径（OD）为1.4毫米，以与当前的支气管镜、导航系统和径向EBUS兼容。本研究中对9头猪进行了治疗，生存时间分别为1周、4周和12周（每个时间点n = 3）。在所有动物中，治疗部位包括右上肺（RUL）的一个位置和右下肺（RLL）的另一个位置。术前、术后即刻以及治疗后每2周进行CT扫描。消融时间为6至8分钟，平均施加功率为68瓦（范围63 - 72瓦）。结果——在1周存活期时，在所有6次消融中均观察到大片坏死组织区域。RUL部位消融体积的平均直径为3.2厘米，RLL部位为3.8厘米（可能是由于RLL消融持续时间更长）。随着时间推移，坏死组织逐渐被纤维组织取代。在4周存活期时，在所有3只相应动物中，这种取代几乎完成。结果，RUL部位消融体积的平均直径降至1.3厘米，RLL部位降至2.3厘米（可能是由于RLL消融持续时间更长）。在12周存活期时，随着取代过程继续，组织病理学显示残留坏死组织区域进一步缩小。消融区域已被纤维瘢痕组织吸收和收缩。治疗效果的平均体积在等效直径上降至1.1厘米（RUL）和1.6厘米（RLL）。9只动物中均未出现并发症。结论——在健康猪肺中，使用外径为1.4毫米、与径向EBUS鞘兼容的支气管内导管进行RFA是有效且安全的。该系统和治疗方法可考虑在肿瘤性肺结节的微创治疗中进行进一步评估。
