An In Vitro Experimental Study of the Pulse Delivery Method in Irreversible Electroporation

Abstract

The purpose of this study was to investigate the feasibility of generating larger ablation volumes using the pulse delivery method in irreversible electroporation (IRE) using a potato model. Ten types of pulse timing schemes and two pulse repetition rates (1 pulse per 200 ms and 1 pulse per 550 ms) were proposed in the study. Twenty in vitro experiments with five samples each were performed to check the effects on the ablation volumes for the ten pulse timing schemes and two pulse repetition rates. At the two pulse repetition rates (1 pulse per 200 ms and 1 pulse per 550 ms), the largest ablation volumes achieved were 1634.1 mm3± 122.6 and 1828.4 mm3±160.9, respectively. Compared with the baseline approach (no pulse delays), the ablation volume was increased approximately by 62.8% and 22.6% at the repetition rates of 1 pulse per 200 ms and 1 pulse per 550 ms, respectively, using the pulse timing approach (with pulse delays). With the pulse timing approach, the ablation volumes generated at the lower pulse repetition rate were significantly larger than those generated at the higher pulse repetition rate (P < 0.001). For the experiments with one pulse train (baseline approach), the current was 5.2 A±0.4. For the experiments with two pulse trains, the currents were 6.4 A±0.9 and 6.8 A±0.9, respectively (P = 0.191). For the experiments with three pulse trains, the currents were 6.6 A±0.6, 6.9 A±0.6, and 6.5 A±0.6, respectively (P = 0.216). For the experiments with five pulse trains, the currents were 6.6 A±0.9, 6.9 A±0.9, 6.5 A±1.0, 6.5 A±1.0, and 5.7 A±1.2, respectively (P = 0.09). This study concluded that: (1) compared with the baseline approach used clinically, the pulse timing approach is able to increase the volume of ablation; but, the pulse timing scheme with the best performance might be various with the tissue type; (2) the pulse timing approach is still effective in achieving larger ablation volumes when the pulse repetition rate changes; but, the best pulse timing scheme might be different with the pulse repletion rate; (3) the current in the base line approach was significantly smaller than that in the pulse timing approach.