Role of Intrauterine Cornual Block in Combination With Direct Cervical Block in Outpatient Endometrial Ablation

Outpatient local anaesthesic (LA) hysteroscopic intrauterine therapeutic interventions such as endometrial ablation have gained wider acceptance in the last decade. However, pain experienced during these procedures can be a disincentive and is the commonest reason for the use of escalating levels of analgesia post procedure, which results in prolongation of hospital stay and recovery. Various methods of LA have been studied including intrauterine topical lignocaine or cervical block using topical lignocaine, paracervical block or intracervical block. However, a single site block individually may not be sufficient to control the pain completely due to inability of the one site block to affect the sensitivity of the whole uterus, as the uterine fundus is effectively still unanaesthetised. This may be due to the uterus receiving complex innervations from different nerve routes such as the uterovaginal plexus, the Frankenhauser nerve plexuses, parasympathetic ganglia and the thoracic nerve.

Therefore, it seems logical to use a direct cervical block to block the sensation through uterovaginal plexus and use an additional deep myometrial block adjacent to each cornua to directly block the thoracic nerve supply. To date, only one small observational study has looked at the effect of such a combined block in relieving pain during outpatient hysteroscopic procedures. Therefore, we propose to undertake a double blind randomised controlled trial to address this question by comparing effectiveness of a standard direct cervical block and intrauterine cornual block (ICOB) versus a direct cervical block and a normal saline intrauterine cornual injection (control).

Inclusion criteria

• All women between the ages of 18 - 50 years presenting to the gynaecology outpatient clinic scheduled for an outpatient hysteroscopic intrauterine therapeutic intervention such as endometrial ablation.

Exclusion criteria

• Women with contraindications to hysteroscopic procedures such as atypical endometrial hyperplasia or endometrial cancer, undiagnosed abnormal vaginal bleeding, current lower pelvic infection or uterine abnormalities

• Women who are allergic to local anaesthesia
• Not technically possible to perform a hysteroscopy e.g. women with distorted uterine cavity due to large fibroids
• Women considered vulnerable (e.g. current mental illness, emotionally labile, or learning difficulties)
• Women who decline to be randomised and request the additional anaesthetic or decline it will form a separate group to be studied and will be administered the VAS similar to the trial group. This group will be analysed separately to determine whether they are significantly different to those patients who consent to being part of the trial.