Background Pharmacology frequently fails for the treatment of epilepsy. the cerebral venous system to map seizure activity is feasible. Radiofrequency energy can be delivered transvenously or transcortically to successful ablate cortical tissue in this animal model using this innovative approach. Keywords: epilepsy catheter ablation venous system radiofrequency cerebral cortex Introduction Epilepsy affects 0.5% to 1% of the world’s population (Engel Wiebe et al. 2003). Despite the best pharmacologic treatments available 40 of patients remain refractory to therapy (Engel 1998; Stephen Kelly et al. 2006). Epilepsy surgery is an alternative way to treat refractory patients and can achieve adequate results (Choi Sell et al. 2008). However it is highly invasive and technically difficult in deep areas Mouse monoclonal to CD45.4AA9 reacts with CD45, a 180-220 kDa leukocyte common antigen (LCA). CD45 antigen is expressed at high levels on all hematopoietic cells including T and B lymphocytes, monocytes, granulocytes, NK cells and dendritic cells, but is not expressed on non-hematopoietic cells. CD45 has also been reported to react weakly with mature blood erythrocytes and platelets. CD45 is a protein tyrosine phosphatase receptor that is critically important for T and B cell antigen receptor-mediated activation. of the brain (Wyllie Chee et al. 1993). New and less invasive experimental techniques have been developed to achieve access to critical areas of the cerebral cortex for epilepsy treatment using the venous system Ebastine (Henz Friedman et al. 2008; Bower Stead et al. 2013). The aim of this study was to assess the feasibility and efficacy of minimally invasive transvenous mapping and ablation for the treatment of epilepsy using novel catheters in animal models. Methods Animal preparation Eleven baboons (25-30 kg) and three canines (beagles) were studied under general anesthesia using isoflurane (1% to 3%). Intravenous heparin was given with a target ACT of 250 seconds. The studies were performed with the approval of the Mayo Clinic Institutional Animal Care and Use Committee. Retrograde cerebral venous access and arterial access was obtained via the internal jugular vein femoral vein internal carotid artery and femoral artery for angiography and mapping. A 4-Fr multipurpose catheter was inserted near the ostium of the jugular vein for venous angiography and in the internal carotid artery for arterial phase angiography. Both vessels were used for subsequent placement of mapping and ablation catheters in both the venous and arterial systems. Following transvenous mapping and ablation craniotomy was performed with exposure of the parietal cortex. Induction mapping and ablation of the presumed seizure focus were then repeated under direct visualization through the craniotomy. Electrical mapping and ablation Transvenous mapping and ablation Transvenous mapping of cortical electrograms from the occipital temporal and parietal lobes was performed through the cortical veins using the following experimental catheters: (1) over-the-wire 4.5-Fr mapping and temperature controlled irrigated ablation catheter (Figure 1A) to negotiate the tortuous cortical veins and (2) Ebastine a 4.5-Fr open-irrigation balloon-virtual electrode venous ablation catheter (Figure 1B) for larger lesion creation in the high impedance cerebral cortex environment. Mapping was also performed using commercially available catheters a 2.7-Fr octapolar microelectrode catheter (Revelation Cardima? Fremont CA) and a 6-Fr 4-mm tip deflectable catheter (Blazer Boston Scientific? Natick MA). Electrograms were recorded using a multichannel recording system (Prucka? General Electric Milwaukee USA) with filter settings of 0.5-500 Hz. Figure 1 Engineering design of novel catheters used for CNS cortical mapping and ablation Seizures were induced by one of two techniques: pacing maneuvers (10 baboons) Ebastine or cortical penicillin injection (4 baboons and 1 dog). The mapping catheter was navigated to cortical veins at different locations and pacing was performed at high (200 Hz) and low (50-200 Hz) frequencies. We obtained stimulation threshold values by varying energy from 2 mA to 20 mA at a pulse width of 2 ms and assessing for lowest value required for cerebral tissue activity. Pacing was then used to induce seizures. Alternatively 2500 U of crystalline penicillin was injected over a skull aperture in pre-determined areas located close to the site of catheter ablation. Penicillin injections induced large amplitude periodic epileptiform spikes. These injections were made to produce partial seizure activity in order to capture from the venous system brain signals close to ablation sites. The induced seizure was mapped using the transvenously Ebastine introduced catheter. Radiofrequency energy was delivered at pre-specified. Ebastine