Table 6  Results of studies with bipolar radiofrequency ablation.

Study	n	Comparison	End points	Follow-up period (months)	Results
Abbott et al. 2003 33 Randomised study	55	Radiofrequency ablation vs. Thermal balloon (Cavaterm)	Amenorrhoea rate after 12 months Pain 4 hours postoperatively	12 (postop.)	Amenorrhoea: 43% vs. 12% (p = 0.04) Pain 48% vs. 78% (p = 0.01)
Bongers et al. 2004 29 Kleijn et al. 2008 30 Randomised study	126	Radiofrequency ablation vs. Thermal balloon (Thermachoice)	Amenorrhoea rate Patent satisfaction	12 (postop.)	Amenorrhoea: 43% vs. 8% (p < 0.001) Satisfaction 90% vs. 79% (p = 0.003)
			Amenorrhoea rate Hysterectomy rate Quality of life	60 (postop.)	Amenorrhoea: 48% vs. 23% (p < 0.001) Hysterectomy rate 9.9% vs. 12.9%, HR 1.2 Quality of life same (p = 0.73)
Clark et al. 2011 17 Randomised study	81	Radiofrequency ablation vs. Thermal balloon	Amenorrhoea Duration of surgery	6 (postop.)	Amenorrhoea 39% vs. 21% (p = 0,1) Duration of RF on average 6.2 min shorter (p < 0.001)
Penninx et al. 2016 34 Randomised study	104	Comparison of bipolar radiofrequency ablation vs. Thermal balloon (Thermablate)	Amenorrhoea rate Patient satisfaction Repeat intervention rate	12 (postop.)	Amenorrhoea rate 56% vs. 23%, RR 0.6, 95% CI 0.4 – 0.8 Patient satisfaction 87% vs. 69%, RR 0.44, 95% CI 0.2 – 0.97 Repeat intervention rate 10% vs. 12%, RR 1.02, 95% CI 0.9 – 1.2
Penninx et al. 2011 35 Randomised study	160	Radiofrequency ablation vs. Hydrothermal ablation	Amenorrhoea rate Repeat interventions	60 (postop.)	Amenorrhoea 55,4% vs. 35,3%, RR 1,5, 95% CI 1,05 – 2,3 Repeat interventions 17% vs. 48%, RR 0.43, 95% CI 0.23 – 0.80
Muller et al. 2015 36 Retrospective study	505	Radiofrequency ablation (289 pat.) vs. Thermal balloon (ThermaChoice) (216 pat)	Amenorrhoea rate Hysterectomy rate	35 (Median)	Amenorrhoea 45% vs. 27% (p = 0.001) Hysterectomy rate 13% vs. 19% (p = 0.066)
Ferguson et al. 2015 37 Retrospective study	1994	Hysterectomy rate following radiofrequency ablation	Hysterectomy rate	48 (Median)	Hysterectomy in 203 pat. (10%) Indication: bleeding 117 (58%); pain 31 (15%), bleeding and pain 45 (22%), other 10 (5%)
Wyatt et al. 2016 38 Retrospective study	144	Dysmenorrhoea rate before and after bipolar radiofrequency ablation	Dysmenorrhoea rate	72 (Median)	Pretherapeutic 69%; post-therapeutic 38% (p < 0.001)
Shazly et al. 2016 28 Retrospective study	1178	Predictors for failure of the radiofrequency ablation	Failure: Hysterectomy or repeat ablation or drug-based ovarian suppression	52 (Median)	Hysterometer > 10.5 cm; HR 2.58 (p = 0.006) Cavity length > 6 cm; HR 2.06 (p = 0.002) Cavity width > 4.5 cm; HR 2.06 (p = 0.002) Cavity surface > 25 cm 2 ; HR 2.02 (p = 0.003) Surgical time < 93 s; HR 2.61 (p = 0.01)
Present study Prospective study	187	Predictors for failure of the radiofrequency ablation	Spotting, amenorrhoea rate, hysterectomy rate	17,5 (Median)	Spotting, amenorrhoea rate: intramural mass, age ≤ 45 years: HR 3.699 (p = 0.036), 95% CI 1.089 – 12.570 Hysterectomy rate: intramural mass, age ≤ 45 years: HR 7.873 (p = 0.033), 95% CI 1.176 – 52.701