Intrauterine fundal anaesthesia during endometrial ablation in the office: A randomised double-blind, non-inferiority trial

Objective: To evaluate the effect of intrauterine fundal anaesthesia during outpatient endometrial ablation.

Study design: A randomised, double-blinded non-inferiority trial was performed in one hospital and one independent treatment center in the Netherlands. A total of 96 women who were planned for a NovaSure® endometrial ablation under local anaesthesia between December 2015 and February 2018 were included in this trial. These women were randomised to paracervical anaesthesia combined with hysteroscopic fundal infiltration with anaesthestics or paracervical anaesthesia combined with hysteroscopic fundal infiltration with saline. The primary outcome was pain during ablation. To study non-inferiority of paracervical anaesthesia without fundal anaesthesia, we assessed the co-primary endpoints Faces Pain Score and Numeric Rating Score. Secondary outcomes included pain scores at other moments during and after the procedure, postoperative use of analgesics, satisfaction, side-effects and complications. The primary outcomes were tested with a non-inferiority margin (2.0 points on changes in pain), and the secondary outcomes were compared using conventional statistical methods.

Results: Paracervical anaesthesia without fundal anaesthesia did not establish non-inferiority to the combination of paracervical anaesthesia and fundal infiltration with anaesthetics when both primary outcome variables of pain were taken into account (Numeric Rating Scale 5.0 versus 3.9 (mean difference 1.2 (95% CI 0.1-2.2)) and Faces Pain Score 5.4 versus 4.8 (mean difference 0.6 (95% CI -0.3-1.5))). Secondary pain scores measured during the procedure were higher or similar in women receiving fundal infiltration with saline as compared to women who received fundal infiltration with anaesthetics. After the procedure, there were no differences in reported pain scores, satisfaction, and side-effects. In the group who received fundal infiltration with saline, more women were admitted to the hospital because of severe pain (3 versus 0 women) and endometritis (1 versus 0 women).

Conclusion: This study did not confirm non-inferiority of paracervical anaesthesia without fundal anaesthesia to the combination of paracervical anaesthesia with fundal anaesthesia in the reduction of pain during endometrial ablation and therefore provides no reason to leave out fundal anaesthesia. We recommend to use fundal anaesthesia combined with paracervical anaesthesia to reduce pain during endometrial ablation in the office.