Comparison of tissue effects quantified histologically between PlasmaJet coagulator and Helica thermal coagulator

INTRODUCTION: The PlasmaJet (PJ) coagulator uses neutral pure argon plasma to achieve coagulation. Helica thermal coagulator (HTC) achieves coagulation with helium gas. HTC is currently used in the treatment of mild to moderate endometriosis. OBJECTIVE: The objective of this study was to compare the tissue damage caused by PJ to the HTC in the uterus, ovary and fallopian tube. Our hypothesis was that PJ is a safe technology to use and the tissue damage caused is comparable to HTC. METHODS: Fifteen subjects undergoing hysterectomy with or without salpingo-oophorectomy were prospectively recruited for in vivo assessment of the two instruments. Both instruments were used on a small area of uterus, ovary and fallopian tube following the ligation of uterine artery pedicle. PJ was used at a power setting of 20 % for duration of 5 s at a clinically acceptable distance of 0.5 to 1 cm from the tissue surface. HTC was used at a widely accepted low power setting in the treatment of endometriosis for a similar duration and distance. Tissue damage was evaluated histologically. ANOVA was used to compare the mean differences. RESULTS: Data were normally distributed. Five subjects had a subtotal hysterectomy and 10 had hysterectomy with salpingo-oophorectomy. A total of 15 uteri, 10 ovaries and 10 fallopian tubes were histologically analysed for the tissue effect of PJ and HTC. There was no significant difference in the mean ± SD depth of tissue damage seen between PJ and HTC in the uterus (0.63 ± 0.19 vs. 0.68 ± 0.18; P = 0.481), ovary (0.61 ± 0.14 vs. 0.67 ± 0.15; P = 0.420) and fallopian tube (0.63 ± 0.18 vs. 0.60 ± 0.13; P = 0.688). A significantly lesser lateral spread of tissue damage (width) was seen with PJ than HTC in all three tissue types (uterus: 4.66 ± 0.91 vs. 7.67 ± 1.21, P < 0.001; ovary: 4.05 ± 0.61 vs. 5.90 ± 0.95, P < 0.001; fallopian tube: 4.50 ± 0.77 vs. 6.00 ± 1.28, P = 0.034). CONCLUSION: The depth of tissue damage caused by PJ at 20 % power is comparable to that with HTC on gynaecological tissues. The lateral spread (width of tissue damage) is however lesser with PJ than with HTC.