Study on thermal damage of bipolar plasma hysteroscope

Objective:To explore the thermal damage during transcervical resection of endometrium(TCRE) under bipolar plasma hysteroscope,seek safe and effective operative wattage settings.Methods:The powers of electrocision electrode were 160 W,200 W,and 280 W,respectively;the powers of electrocoagulation electrode were 80 W and 200 W,respectively;the operating times were 3-5 seconds and 6-8 seconds,respectively.TCRE was performed,then the isolated uteri were treated with HE staining and NADH-d staining,the deepness of thermal damage and histopathological changes were observed.Results:Under the circumstance of the same power and operating time,the deepness of thermal damage under the coagulation electrode was deeper than that under the cutting electrode;when electric coagulation was performed,there was a certain correlation between the deepness of thermal damage and power,operating time.Under the circumstance of designed power and operating time,the maximal deepness of thermal damage for isolated uteri was 3.68 mm,accounting for 17.6% of uterine wall.Conclusion:TCRE under bipolar plasma hysteroscope is an effective and new technique to treat dysfunctional uterine bleeding,the optimal power of TCRE was 200 W,the power of electric coagulation was 160-200 W.The vitro experiment certifies that TCRE under bipolar plasma hysteroscope is safe,the thermal damage is slight,the method can avoid accidental electric injury,reduce the incidences of uterine perforation and surrounding organs injury.The vitro experiment shows the thermal damage under the coagulation electrode is severer than that under the cutting electrode during TCRE under bipolar plasma hysteroscope,more attention should be paid to the power of electric coagulation electrode and the choice of operating time.