Histological quantification of the tissue damage caused by PlasmaJet(TM) coagulator

The purpose of this study was to evaluate tissue damage caused by the PlasmaJet(TM) coagulator in the uterus, ovary, and fallopian tube at different power settings in vitro and then to examine the damage caused in vivo. In vitro evaluation included prospective recruitment of six subjects undergoing hysterectomy with or without salpingo-oophorectomy. Tissue damage was evaluated histologically for power levels at 10%, 15%, and 20%, and for duration of 2 and 5 s at a clinically acceptable distance of 0.5 to 1 cm between the tip of probe and tissue. In vivo evaluation included 15 subjects undergoing hysterectomy with or without salpingo-oophorectomy. The most suitable power setting and duration of diathermy was decided from in vitro examination and applied on in vivo setting. Tissue damage was evaluated histologically. There was no significant difference seen in the depth and width of tissue damage in the in vitro specimens at different low power levels and duration of diathermy (P>0.05). A setting of 20% power and duration of 5 s of diathermy was used therefore for in vivo setting. Mean +/- SD depth (millimetres) of tissue damage in uterus, ovary, and fallopian tube were 0.63 +/- 0.19, 0.61 +/- 0.14, and 0.63 +/- 0.18, respectively. Mean +/- SD width (millimetres) of tissue damage in uterus, ovary, and fallopian tube were 4.66 +/- 0.05, 4.05 +/- 0.61, and 4.51 +/- 0.77, respectively. Irre-spective of tissue type, the average depth and width of tissue damage with application of Plasmajet(TM) coagulator for 5 s at low power is 0.62 and 4.24 mm, respectively. It therefore appears to be a safe method of coagulation in vitro and in vivo at 20% power on gynaecological tissues.