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 1 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.

Magnetic resonance imaging appearances of the uterus following microwave endometrial ablation.

AIM: Microwave endometrial ablation (MEA) is a treatment for dysfunctional uterine bleeding. It is a second generation ablative technique which is as effective as hysteroscopic methods but quicker and easier to perform. Our aim is to describe the Magnetic Resonance Imaging (MRI) appearances of the uterus following this procedure. METHODS: 15 women underwent MRI immediately before MEA, and again at one day and 4 months after treatment. T1 and T2 sequences were performed at 1.0T using a body coil. Images were assessed by 2 independent observers for quantitative and qualitative changes. Clinical questionnaires were completed before treatment and at 4 months. RESULTS: On images obtained one day post-ablation, 14 patients had a low signal intensity band subjacent to the treated area of the endometrial cavity on T2 images. Imaging at 4 months showed significant amounts of endometrial tissue in 11 patients, including 3 of the 6 patients who were amenorrhoeic. There were no changes in the appearances of myometrium or uterine dimensions and there were no haematometra. CONCLUSIONS: The detection of residual endometrium by MRI means that unopposed oestrogen hormone replacement therapy should be avoided after MEA, even in women who have amenorrhoea. Thepost-operative sub-endometrial low signal intensity zone corresponds to the region of tissue necrosis detected on vital staining of the treated uterus in in vivotesting. Depth of tissue destruction is a surrogate marker for clinical effectiveness. MRI may have a role in early assessment of patients participating in clinical research who are undergoing a modified MEA technique while retaining their uterus.