MYOLYSIS OR THERMOABLATION: A NEW THERAPY FOR UTERINE FIBROMA

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Transvaginal ultrasound-guided thermoablation is a technique currently only performed in a few centres. Prof La Marca personally handles the method and receives patients from all over the country to perform this innovative therapy. It is an ultra minimally invasive technique that only requires a hospital stay of a few hours. 

Uterine fibroma is a benign solid tumour that originates at the level of the uterine smooth muscle, with a prevalence rate of up to 70%, representing the most common benign uterine tumour in women during their reproductive years. Fibroids are diagnosed in women of all ages, but are most commonly found in women between the ages of 35 and 50.

Although they are benign and may be asymptomatic, approximately 30% of fibroids cause uterine bleeding that is abnormal in quantity and duration, dysmenorrhoea, pelvic discomfort and pain due to pressure on adjacent organs and structures, as well as obstetrical complications such as infertility, recurrent miscarriage or preterm labour. These symptom pictures can be particularly detrimental to a woman's physical well-being, emotional state, social interactions and quality of life.

Due to their prevalence and associated symptomatology, uterine fibroids constitute a significant social and health problem, leading to gynaecological admissions and approximately 80% of all hysterectomies. Therefore, the management of abnormal uterine bleeding and the symptoms listed above is crucial to improving the quality of life of women diagnosed with fibromatosis.

Several treatments are available for fibroids and their associated symptoms, ranging from pharmacological medical management to conventional and newer, less invasive surgical options. The choice of an appropriate treatment option takes into account various aspects, such as the size, number and location of fibroids, the presence of symptoms, the patient's age, the desire to preserve fertility, and the individual patient's preferences.

Interest in less invasive fertility-preserving techniques has increased in recent decades. Studies are reported in the literature showing that 80% of women prefer less invasive alternatives for the management of fibroids and 50% of them wish to preserve the uterus.

Minimally invasive treatments for uterine smooth muscle tumours are designed with the aim of preserving women's fertility but may also represent a promising alternative treatment option for women with a high surgical risk. Such treatments include uterine artery embolisation, focused ultrasound guided by magnetic resonance imaging, and radiofrequency or microwave ablation (also known as interstitial myolysis).

Radiofrequency or microwave myolysis refers to the ablation of uterine fibroids using focused energy with an electric current through an electrode, with radiofrequency or microwaves used as the energy source. It is a procedure involving thermal ablation aimed at coagulating the fibroid tissues instead of removing them completely.

The mechanism by which radio frequency or microwave heats tissue is through resistive heating of a narrow flap of tissue in direct contact with the electrode. Deeper tissue planes are then heated by conduction from the small volume heating region. The heat is dissipated from the region by further thermal conduction into the normothermic tissue. It is a technique that is already used in other medical fields, such as in the treatment of lung, kidney or liver cancer, so it is a procedure with a large case history.

Myolysis was first used laparoscopically and then hysteroscopically or transvaginally under ultrasound guidance. Transvaginally ultrasound-guided myolysis has been shown to reduce the volume of fibroids resulting in improvement and relief of symptoms. Many studies have demonstrated the medium- and long-term therapeutic effect of this procedure; few studies have reported adverse outcomes and most of the reported complications were minor events, such as pain, vaginal discharge and pelvic adhesions. It is a safe and effective treatment option that does not require hospitalisation and has a reduced risk of intraoperative bleeding compared to laparoscopic myomectomy.

Myolysis generates thermal effects within the myoma (60-80 °C) and results in three distinct therapeutic histological changes: (1) necrosis of the tissue cells by coagulation, (2) the formation of vascular thrombosis in the blood vessels supplying the myoma resulting in necrosis/ischaemic atrophy, and (3) the inactivation of hormone receptors within the myoma preventing the tumour tissue from growing.

In conclusion, myolysis with radiofrequency or microwaves can be considered a minimally invasive and safe method for the treatment of uterine myomas through customisation and possible combination of transvaginal, laparoscopic or hysteroscopic access, ensuring less pain, fewer complications and earlier healing. Standardisation of the ablation technique with pre-intervention biopsy and new technologies spare healthy uterine tissue and may change the future management of symptomatic uterine fibroids. It is important to carefully select patients for myolysis, considering the number, size and location of the myoma. As always, the operator's experience is then decisive in determining therapeutic success.

 

References

Chung-Hoon Kim, et al. Transvaginal ultrasound-guided radiofrequency myolysis for uterine myomas. Hum Reprod. 2011 Mar;26(3):559-63. doi: 10.1093/humrep/deq366.

Ning Hai , Xiaoping Ding. Intrauterine adhesion after transvaginal ultrasound-guided radiofrequency myolysis. J Obstet Gynaecol Res . 2015 Nov;41(11):1851-4. doi: 10.1111/jog.12796.