Objective:To investigate the effect of irreversible electroporation(IRE)ablation on the structure of blood vessels. Methods:Pulsed electric fields(PEFs) with permanent duration(100 μs)

frequency(1 Hz)

voltage(2 000 V) and pulses(120 pieces) were performed on the electrodes which were placed under ultrasound guidance through the animal skin to the target area. The treated area was observed by real-time ultrasound scanning and color Doppler flow imaging at 24 hours after IRE ablation. Histological changes of the blood vessels in treated areas were observed by HE staining and Masson staining. Results:Gross section examination showed the structural integrity of vascular within IRE-ablated zone. The imaging of two-dimensional ultrasound showed that blood vessels were intact and there was color doppler flow imaging in blood vessels. Endothelial cells of blood vessels were not ablated by IRE.The blood vessel wall structures which mainly formed by vascular elastic and collagenous structures

peri-cellular matrix proteins and vascular smooth muscle structures was not damaged. Conclusion:IRE-ablation retains important vital structures such as hepatic arteries

hepatic veins

intra--hepatic bile duct and perivascular elastic fiber structure and collagen fiber structure in the ablation zone.IRE could produce a more complete ablation effect even there are large vessels traversing though the ablation zone.