Endometrial ablation is a procedure where the endometrium of the uterus is destroyed. It is a treatment option in the surgical management of abnormal uterine bleeding (AUB) – heavy menstrual bleeding without an attributable cause.
With correct patient selection, the procedure is thought to be 80–90% successful in decreasing the amount of menstrual flow. Approximately 40–50% of the patients report becoming amenorrheic (no periods).
In this article, we shall look at the procedure, indications and complications of endometrial ablation.
Endometrial Ablation Techniques
There are several techniques/modalities for performing endometrial ablation.
A hysteroscopy is usually performed prior to endometrial ablation to assess the suitability of the endometrial cavity for the specific modality chosen.
Transcervical Resection of the Endometrium (TCRE).
This technique requires a general anaesthetic. A resectoscope (operating hysteroscope) is used to remove or destroy the endometrium using diathermy energy (usually monopolar).
Either a small electrical wire loop is used to shave off the endometrium, or a ball is used to burn/destroy the endometrium. The latter is very time consuming and not commonly used.
TCRE has generally now been superseded by modern devices, which are less time consuming and do not necessitate general anaesthesia.
Balloon Ablation (e.g. Thermachoice or Thermablate)
A balloon filled with heated fluid sits inside the uterus for a pre-specified length of time to destroy the endometrium. The deflated balloon is first inserted into the uterus and then filled. The fluid may be pre-heated or heated inside the uterus. The treatment time is 2 minutes (for thermablate) to 8 minutes (for thermachoice). This method may be performed under local anaesthetic or general anaesthetic, depending on the treatment time. Cervical dilatation is required.
Microwave Energy (e.g. Minitouch)
An intrauterine device is used to deliver microwave energy into the endometrial cavity to destroy the endometrium. The treatment time is 72 seconds or less. This method does not require dilatation of the cervix and it may be performed under local anaesthetic.
Bipolar Mesh (e.g. Novasure)
A bipolar energy mesh is inserted into the uterus, expanded and then energy delivered to the endometrium. This technique requires cervical dilatation and may be performed under local or general anaesthesia depending on the woman’s preference.
Other devices/ techniques also available , for example hydrothermal ablation where saline is infused into the endometrial cavity and then heated.
Balloon may be more suitable for women with an irregular endometrial cavity, compared with Minitouch or Novasure, because the balloon can mould around any irregularities, for example if a submucosal fibroid is present.
Endometrial ablation is used in the treatment of heavy periods (menorrhagia). It is a much less invasive option than hysterectomy for the effective treatment of this common problem.
Endometrial ablation can only be offered to women who have completed their family, and reliable contraception is required following the procedure. Although pregnancy is unlikely, it can be associated with life-threatening complications, mainly as a result of placenta praevia and/or placenta accreta (abnormally adherent placenta).
Endometrial ablation is contraindicated in women who would like to retain their fertility or who have a diagnosis of endometrial hyperplasia or malignancy.
The procedure is considered to be less effective in women under 35 or, in cases where pain is a major associated symptom, or where the uterus is enlarged.
The procedure may not be possible for women with a large uterus and in women with submucosal fibroids distorting the endometrial cavity.
The overall complication rates are low, however non-resectoscopic endometrial ablation is considered to have a more favourable safety profile. With resectoscopic techniques, there is a small risk of fluid overload and electrolyte disturbances.
Intraoperative injury, such as cervical laceration or uterine perforation, can occur when the cervix is dilated or at any point during the procedure. It is rare to have perioperative haemorrhage due to this procedure. Bowel and bladder injury is also a very rare complication of endometrial ablation.
Since energy is applied to the endometrium during the procedure, it results in inflammation and tissue necrosis. The inflammatory response may lead to intrauterine scarring and tissue contraction. Since not all areas of the endometrium are equally targeted, this can lead to an obstructed outflow of menstrual blood, which may subsequently lead to haematometra (central and cornual) and pelvic pain.