A randomised trial comparing local versus general anaesthesia for microwave endometrial ablation

Objective To compare the acceptability of microwave endometrial ablation using a local anaesthesia/sedation regime or general anaesthesia. To compare recovery following treatment with each type of anaesthetic.

Design Prospective randomised controlled trial with follow up of women who declined randomisation.

Setting The gynaecology department of a large teaching hospital in the UK.

Population All women referred for microwave endometrial ablation at the Aberdeen Royal Infirmary between July 1999 and September 2000 without a medical reason to favour one or other type of anaesthetic.

Methods 191 women were equally randomised to undergo microwave endometrial ablation under general or local anaesthesia. Details were also collected for women not randomised because of an anaesthetic preference. All procedures were undertaken in an operating theatre.

Main outcome measures Data collected by questionnaire including the woman's view of treatment acceptability, operative details and post-operative recovery.

Results Sixty-nine percent of eligible women would consider treatment under local anaesthesia. Ninety-one percent of microwave endometrial ablation procedures that started under local anaesthesia were completed without conversion to general anaesthesia. Anaesthetic type and allocation by randomisation or preference made no significant difference to the proportion of women describing treatment as totally or generally acceptable at two weeks. Neither parity nor cavity size predicted acceptability. Women allocated general anaesthesia were more likely to describe the procedure as totally acceptable and to choose the same anaesthetic again. There was no significant difference between anaesthetic groups regarding post-operative pain, nausea or recovery time.

Conclusions Microwave endometrial ablation under local anaesthesia was acceptable to the majority of women referred for treatment. There was no recovery advantage from local anaesthesia and almost I in 10 women who starting treatment under local anaesthesia needed a general anaesthetic because of discomfort. The incidence of post-operative pain and nausea means that treatment with this local anaesthetic/sedation regime remains a day case rather than an outpatient procedure.