@article {Trujillo2013, title = {{Can electroporation previous to radiofrequency hepatic ablation enlarge thermal lesion size? A feasibility study based on theoretical modelling and in vivo experiments.}}, journal = {International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group}, volume = {29}, number = {3}, year = {2013}, pages = {211{\textendash}8. {\textcopyright} 2013 Informa UK Ltd.}, abstract = {

PURPOSE: The aim of this study was to assess the feasibility of a hybrid ablative technique based on applying electroporation (EP) pulses just before conducting radiofrequency ablation (RFA). The rationale was that the EP-induced reduction in blood perfusion could be sufficient to reduce the thermal sink effect and hence to increase the coagulation volume in comparison to that created exclusively by RFA. MATERIALS AND METHODS: A modelling study and in vivo experimental study were used. A Cool-tip RF applicator was used both for EP and RFA. RESULTS: Overall, the results did not show any synergy effect from using the hybrid technique. Applying EP pulses prior to RFA did not increase the coagulation zone obtained and the lesions were almost identical. Additional computer simulations provided an explanation for this; the effect of reducing blood perfusion by thermal damage during RFA completely masks the effect of reducing blood perfusion by EP. This is because both thermal damage and EP affect the same zone, i.e. the tissue around the electrode. CONCLUSIONS: Our computer modelling and in vivo experimental findings suggest that the combination of EP and RFA with monopolar applicators does not provide an additional benefit over the use of RFA alone.

}, keywords = {Animals, Catheter Ablation, Combined Modality Therapy, Computer Simulation, Electroporation, Feasibility Studies, Female, Liver, Liver: surgery, Models, Swine, Theoretical}, issn = {1464-5157}, doi = {10.3109/02656736.2013.777854}, url = {http://www.ncbi.nlm.nih.gov/pubmed/23573935}, author = {Trujillo, Macarena and Q. Castellv{\'\i} and Burd{\'\i}o, Fernando and Patricia S{\'a}nchez-Vel{\'a}zquez and Antoni Ivorra and Andaluz, Anna and Berjano, Enrique} } @article {Jose2012, title = {{Irreversible electroporation shows efficacy against pancreatic carcinoma without systemic toxicity in mouse models.}}, journal = {Cancer letters}, volume = {317}, number = {1}, year = {2012}, pages = {16{\textendash}23}, abstract = {

Pancreatic ductal adenocarcinoma (PDAC) therapies show limited success. Irreversible electroporation (IRE) is an innovative loco-regional therapy in which high-voltage pulses are applied to induce plasma membrane defects leading to cellular death. In the present study we evaluated the feasibility of IRE against PDAC. IRE treatment exhibited significant antitumor effects and prolonged survival in mice with orthotopic xenografts. Extensive tumor necrosis, reduced tumor cell proliferation and disruption of microvessels were observed at different days post-IRE. Animals had transient increases in transaminases, amylase and lipase enzymes that normalized at 24h post-IRE. These results suggest that IRE could be an effective treatment for locally advanced pancreatic tumors.

}, keywords = {Alanine Transaminase, Alanine Transaminase: blood, Amylases, Amylases: blood, Animals, Aspartate Aminotransferases, Aspartate Aminotransferases: blood, Biological Markers, Biological Markers: blood, Blood Glucose, Blood Glucose: metabolism, Carcinoma, Cell Line, Cell Proliferation, Electrochemotherapy, Electrochemotherapy: adverse effects, Feasibility Studies, Genes, Humans, Lipase, Lipase: blood, Luminescent Measurements, Male, Mice, Microvessels, Microvessels: pathology, Necrosis, Nude, Pancreatic Ductal, Pancreatic Ductal: blood, Pancreatic Ductal: blood supply, Pancreatic Ductal: genetics, Pancreatic Ductal: pathology, Pancreatic Ductal: therapy, Pancreatic Neoplasms, Pancreatic Neoplasms: blood, Pancreatic Neoplasms: blood supply, Pancreatic Neoplasms: genetics, Pancreatic Neoplasms: pathology, Pancreatic Neoplasms: therapy, Reporter, Time Factors, Transfection, Tumor, Xenograft Model Antitumor Assays}, issn = {1872-7980}, doi = {10.1016/j.canlet.2011.11.004}, url = {http://www.ncbi.nlm.nih.gov/pubmed/22079741}, author = {Jos{\'e}, Anabel and Sobrevals, Luciano and Antoni Ivorra and Fillat, Cristina} } @article {Ivorra2011, title = {{Electrochemical prevention of needle-tract seeding.}}, journal = {Annals of biomedical engineering}, volume = {39}, number = {7}, year = {2011}, month = {jul}, pages = {2080{\textendash}9}, abstract = {

Needle-tract seeding refers to the implantation of tumor cells by contamination when instruments, such as biopsy needles, are employed to examine, excise, or ablate a tumor. The incidence of this iatrogenic phenomenon is low but it entails serious consequences. Here, as a new method for preventing neoplasm seeding, it is proposed to cause electrochemical reactions at the instrument surface so that a toxic microenvironment is formed. In particular, the instrument shaft would act as the cathode, and the tissues would act as the electrolyte in an electrolysis cell. By employing numerical models and experimental observations reported by researchers on Electrochemical Treatment of tumors, it is numerically showed that a sufficiently toxic environment of supraphysiological pH can be created in a few seconds without excessive heating. Then, by employing an ex vivo model consisting of meat pieces, validity of the conclusions provided by the numerical model concerning pH evolution is confirmed. Furthermore, a simplified in vitro model based on bacteria, instead of tumor cells, is implemented for showing the plausibility of the method. Depending on the geometry of the instrument, suitable current densities will probably range from about 5 to 200 mA/cm(2), and the duration of DC current delivery will range from a few seconds to a few minutes.

}, keywords = {Animals, Electrochemistry, Electrochemistry: methods, Equipment Contamination, Equipment Contamination: prevention \& control, Humans, Needles, Neoplasm Seeding, Neoplasms, Neoplasms: etiology, Neoplasms: prevention \& control}, issn = {1573-9686}, doi = {10.1007/s10439-011-0295-4}, url = {http://www.ncbi.nlm.nih.gov/pubmed/21400019}, author = {Antoni Ivorra} } @article {Ivorra2011a, title = {{Remote electrical stimulation by means of implanted rectifiers.}}, journal = {PloS one}, volume = {6}, number = {8}, year = {2011}, pages = {e23456}, abstract = {

Miniaturization of active implantable medical devices is currently compromised by the available means for electrically powering them. Most common energy supply techniques for implants{\textendash}batteries and inductive couplers{\textendash}comprise bulky parts which, in most cases, are significantly larger than the circuitry they feed. Here, for overcoming such miniaturization bottleneck in the case of implants for electrical stimulation, it is proposed to make those implants act as rectifiers of high frequency bursts supplied by remote electrodes. In this way, low frequency currents will be generated locally around the implant and these low frequency currents will perform stimulation of excitable tissues whereas the high frequency currents will cause only innocuous heating. The present study numerically demonstrates that low frequency currents capable of stimulation can be produced by a miniature device behaving as a diode when high frequency currents, neither capable of thermal damage nor of stimulation, flow through the tissue where the device is implanted. Moreover, experimental evidence is provided by an in vivo proof of concept model consisting of an anesthetized earthworm in which a commercial diode was implanted. With currently available microelectronic techniques, very thin stimulation capsules (diameter \<500 {\textmu}m) deliverable by injection are easily conceivable.

}, keywords = {Animals, Electric Stimulation, Electric Stimulation: instrumentation, Electric Stimulation: methods, Electrodes, Implanted, Oligochaeta, Software}, issn = {1932-6203}, doi = {10.1371/journal.pone.0023456}, url = {http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3151300\&tool=pmcentrez\&rendertype=abstract}, author = {Antoni Ivorra} }