Treatment of uterine fibroids

• Uterine fibroids are benign tumours in the pelvic area that occur in the uterus of women, especially after the third decade of life.
• There are two types of treatment for uterine fibroids: pharmacological and surgical.
• In most cases, the only definitive treatment for uterine fibroids is surgery.

Uterine fibroids are the most common pelvic tumours, generally of benign origin, in women of any age range, being more common from the 3rd or 4th decade of life onwards. This tumour is produced by the clonal growth of a single cell in the uterus in at least 60% of cases, with the rest of the causes and origins being multifactorial. 

Uterine fibroids are also known as uterine leiomyomas, fibromyomas, leiofibromyomas and fibroleiomyomas and from a cellular point of view they are composed of large amounts of an extracellular matrix made up of various proteins (collagen type I and II, proteoglycans and fibronectin).

Epidemiologically speaking, at least 20-40% of women of reproductive age are affected by fibroids and of these only 20-25% show symptoms, so that the vast majority of affected women are unaware of the presence of fibroids inside the uterus. In autopsy studies of women (cadavers), the presence of fibroids of any size has been estimated in 80% of the uteri studied.

It is generally understood within the medical community that women who suffer from uterine fibroids and who do not have accompanying symptoms or symptoms caused by them, should maintain a wait-and-see attitude from a medical point of view. In these cases, an annual check-up and follow-up is recommended.

For women with symptoms, treatment for uterine fibroids will depend on the size of the lesion, its location, its symptoms, the woman's age, her obstetric and gynaecological history and whether her reproductive desires have already been fulfilled.

For those women who choose to start treatment aimed at resolving uterine fibroids, we will divide the options into two main groups: medical or pharmacological treatment and surgical treatment.

Pharmacological treatment of uterine fibroids

Pharmacological treatment for uterine fibroids should be considered as the first line of therapeutic options when the patient is accessing specific treatment for uterine fibroids for the first time, although generally only surgical treatment will offer a permanent and definitive solution for this type of uterine myomatous lesion.

Pharmacological treatment of uterine fibroids aims to alleviate the accompanying symptomatology which, as we have seen in previous texts, mainly consists of abnormal uterine bleeding, presence of iron deficiency and/or anaemia, pelvic pain, obstructive urinary and intestinal symptoms and infertility.

This medical treatment for uterine fibroids focuses on taking different hormonal components with mixtures of oestrogens and progestins, oestrogen receptor modulators (which are the biological targets of uterine fibroids where natural oestrogens settle and promote the overgrowth of fibroids inside the uterus) and androgen therapy.

Oestrogen and progestogen mixtures aim to atrophy the endometrium (the layer that surrounds the uterus from the inside and under which the vast majority of fibroids are located), thereby stabilising or reducing the size of uterine fibroids.

Oestrogen receptor modulators are substances that compete with natural oestrogens for access to the myoma's own oestrogen receptors. 

When one of the substances derived from the use of these modulators binds to the receptor, it inactivates it, thereby decreasing myoma growth, inhibiting the normal ovarian cycle and altering the vascularisation of the myomas.

Androgen therapy aims to inhibit the hormones that promote the growth of uterine fibroids in the hypothalamus (the organ responsible for secreting the hormones that activate the production of oestrogens and progestogens).

All these products can be taken orally, in the form of a daily pill or monthly intramuscular injection or in the form of an IUD (intrauterine device) with progressive release of the substances specified above locally, inside the uterus.

Surgical treatment of uterine fibroids

Surgical treatment for uterine fibroids is clearly the most effective short and long-term therapy for the definitive resolution of uterine fibroids. The main indications for surgical treatment of uterine fibroids are abnormal uterine bleeding that is not controlled with medical treatment, the presence of severe anaemia and iron deficiency that is not controlled with other therapeutic means, the growth of fibroids after menopause, infertility and pelvic pressure and pain that is not resolved with the previously established pharmaceutical treatment.

The main forms or types of surgical interventions for the treatment of uterine fibroids are:

• Hysterectomy, or complete removal of the uterus, is the most frequently performed treatment for the resolution of uterine fibroids, especially in women who have already fulfilled their reproductive desires. This type of intervention presents few complications, with <0.1% of cases involving the urinary system and the presence of vesico-vaginal fistulas.
• Abdominal myomectomy: this is the clearest option for women who wish to keep the uterus intact by treating only the medium or large myomas that are causing the current symptoms. This type of intervention requires taking hormones similar to those used in medical treatment for 1 or 2 months prior to the intervention in order to reduce the size of the uterine fibroids to be removed as much as possible. This type of intervention requires access to the uterus through the abdominal wall by making an incision and then suturing the different layers of the abdomen until it reaches the pelvis.
• Laparoscopic myomectomy: this is an alternative to open surgery that proposes abdominal myomectomy, aimed solely at maintaining the integrity of the abdomen as much as possible. In this type of intervention, prior oestrogen and progestogen hormones are not necessary. Access to the wall of the uterus and fibroids is achieved through the introduction of 2 or 3 trocars or surgical instruments in the form of a tube into the abdomen, thus reducing damage to the abdominal wall.

• Hysteroscopic or vaginal myomectomy: this is a procedure in which uterine fibroids are removed through the vagina with the introduction of a hysteroscope. The main contraindications for this type of intervention are the presence of endometrial or cervical cancer, infections of the lower reproductive tract and submucous fibroids that infiltrate the uterine wall by more than 50%.
• Myolysis and cryomyolysis: these are different techniques that aim to eliminate uterine fibroids using laser in the first case or liquid nitrogen in the second. No scientifically proven results have yet been obtained on their superiority over the other techniques.
• Uterine artery embolisation: an interventional technique that consists of locating the uterine arteries that supply the body of the uterus by means of an arteriography of the area. Once they are located, each one of them is channelled and a combination of chemical substances is inserted to generate thrombi inside these arteries, reducing the blood flow to the fibroids and causing them to change their size. The size of the fibroids is reduced by 20-50% within 3 months of embolisation.