Rombouts Steffi J E, Nijkamp Maarten W, van Dijck Willemijn P M, Brosens Lodewijk A A, Konings Maurits, van Hillegersberg R, Borel Rinkes Inne H M, Hagendoorn Jeroen, Wittkampf Fred H, Molenaar I Quintus
Department of Surgery, University Medical Center Utrecht Cancer Center, Utrecht, the Netherlands.
Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands.
PLoS One. 2017 Jan 4;12(1):e0169396. doi: 10.1371/journal.pone.0169396. eCollection 2017.
Irreversible electroporation (IRE) with needle electrodes is being explored as treatment option in locally advanced pancreatic cancer. Several studies have shown promising results with IRE needles, positioned around the tumor to achieve tumor ablation. Disadvantages are the technical difficulties for needle placement, the time needed to achieve tumor ablation, the risk of needle track seeding and most important the possible occurrence of postoperative pancreatic fistula via the needle tracks. The aim of this experimental study was to evaluate the feasibility of a new IRE-technique using two parallel plate electrodes, in a porcine model.
Twelve healthy pigs underwent laparotomy. The pancreas was mobilized to enable positioning of the paddles. A standard monophasic external cardiac defibrillator was used to perform an ablation in 3 separate parts of the pancreas; either a single application of 50 or 100J or a serial application of 4x50J. After 6 hours, pancreatectomy was performed for histology and pigs were terminated.
Histology showed necrosis of pancreatic parenchyma with neutrophil influx in 5/12, 11/12 and 12/12 of the ablated areas at 50, 100, and 4x50J respectively. The electric current density threshold to achieve necrosis was 4.3, 5.1 and 3.4 A/cm2 respectively. The ablation threshold was significantly lower for the serial compared to the single applications (p = 0.003). The content of the ablated areas differed between the applications: areas treated with a single application of 50 J often contained vital areas without obvious necrosis, whereas half of the sections treated with 100 J showed small islands of normal looking cells surrounded by necrosis, while all sections receiving 4x 50 J showed a homogeneous necrotic lesion.
Pancreatic tissue can be successfully ablated using two parallel paddles around the tissue. A serial application of 4x50J was most effective in creating a homogeneous necrotic lesion.
采用针状电极的不可逆电穿孔（IRE）正被探索作为局部晚期胰腺癌的一种治疗选择。多项研究表明，将IRE针置于肿瘤周围以实现肿瘤消融，取得了令人鼓舞的结果。缺点是针放置存在技术困难、实现肿瘤消融所需时间、针道种植风险，以及最重要的是可能通过针道发生术后胰瘘。本实验研究的目的是在猪模型中评估使用两个平行板电极的新型IRE技术的可行性。
12只健康猪接受剖腹手术。游离胰腺以利于极板定位。使用标准的单相体外心脏除颤器在胰腺的3个不同部位进行消融；单次施加50或100J，或连续施加4×50J。6小时后，进行胰腺切除术以进行组织学检查，并对猪实施安乐死。
组织学显示，在分别施加50、100和4×50J的情况下，消融区域中分别有5/12、11/12和12/12出现胰腺实质坏死及中性粒细胞浸润。实现坏死的电流密度阈值分别为4.3、5.1和3.4A/cm²。与单次施加相比，连续施加的消融阈值显著更低（p = 0.003）。不同施加方式下消融区域的情况有所不同：单次施加50J治疗的区域通常包含无明显坏死的存活区域，而接受100J治疗的切片中有一半显示正常外观细胞的小岛被坏死包围，而所有接受4×50J治疗的切片均显示均匀的坏死病变。
使用组织周围的两个平行极板可成功消融胰腺组织。连续施加4×50J在形成均匀坏死病变方面最有效。
