Uterine Myometrium Botulinum Toxin A (BTX) Injections.
The principle is similar to that proposed for BTX injections in the
bladder detrusor under cystoscopy for OAB.
The BTX units are evenly distributed in the anterior and posterior
myometrial wall under hysteroscopic control.
In 2018, we conducted a prospective feasibility study on 30 patients
with severe dysmenorrhoea. The technique and results were presented at
the International Neurotoxin Association - INA’s 2019 International
Toxins Conference (34) and at the ”Convergences PP” annual congress in
Madrid in November 2019 (35).
Uterine myometrial BTX injections are performed under hysteroscopy as an
outpatient procedure using a short-term general anaesthetic. The 5 mm
Bettocchi type hysteroscope has an operating channel for the needle to
pass through.
The effective dose used in this study was 200 IU of BTX,
Incobotulinum-toxin A.
The 200 IU of BTX is diluted in saline and evenly distributed in the
uterine myometrium with 10 injections in each anterior and posterior
muscle wall under hysteroscopic control (figure 1).
All patients fulfilled the PUS criteria and ranged from 17 to 44 years
old.
Severe dysmenorrhoea was found in 24 of the patients (89%), all
patients had a painful uterine trigger at vaginal examination and 2
patients had deep dyspareunia as the main symptom.
A pelvic ultrasound and MRI ruled out pelvic pathology and
endometriosis.
All patients had already received initial treatment such as painkillers,
anti-inflammatory drugs, the contraceptive pill, and menstrual
suppressant therapy.
Pregnancy was contraindicated during the 4 months following the
injection.
Patients were reviewed at 8 weeks, 12 weeks, and 6 months.
They were then assessed on the level of pain using the Visual Analogue
Scale (VAS) and the Quality of Life Questionnaire, using the Medical
Outcomes Study SF-36 (MOS SF-36), validated in French. All patients were
screened for co-morbidities and central pelvic hypersensitivity criteria
using the Convergences PP criteria (36).
In terms of statistical analyses, the pre and post-treatment groups were
compared using the Freidman test for multiple, dependant non-parametric
data. P-values were two tailed and significance was set at the 5%
level.