Myolysis Medical Definition
Myolysis is a medical procedure that uses an energy source to destroy muscle tissue. The energy source stops blood flow and causes necrosis (cell death) within the tissue.
What is fibroid myolysis?
Fibroid myolysis refers to the destruction of the smooth muscle tissue that makes up a fibroid. The procedure works by selectively destroying fibroid tissue with an energy source causing cell death only to the fibroid. Three main energy sources have been used for fibroid myolysis: heat in the form of radiofrequency (RF) ablation or laser energy, cold in the form of liquid nitrogen, and ultrasound energy.¹
Thermomyolysis, using heat to break down muscle tissue, is the most common method of myolysis. Probes are inserted into the fibroid through which thermal energy is applied. The amount of tissue affected depends on the amount of energy applied and the location of the probe.
Cryomyolysis uses rapid cooling to freeze uterine fibroid tissue, inducing cell death and fibroid tissue loss. This technique is favored by some physicians as it can be more predictable and the ice ball formed by each probe can be imaged using ultrasound in real-time.¹
A newer myolysis technique uses MRI guidance to focus ultrasound waves onto the fibroid without the insertion of a probe, causing fibroid tissue breakdown. MRI guidance has the benefit of emitting no radiation onto the patient while also providing precise imaging to observe effects on any surrounding tissue.¹
Access To The Fibroid
Access to the fibroid can be obtained by different methods. Laparoscopy used to be the only method for thermomyolysis and cryomyolysis, where small incisions are made in the abdomen in order to insert myolysis probes into the uterus under camera guidance. Some physicians have now adopted techniques where radiofrequency or microwave ablation probes can be inserted through the vagina (transvaginally) or through the skin (percutaneously) using ultrasound guidance, reducing the need for any kind of open surgery.¹⁻³
How does myolysis treat fibroids?
Myolysis works by selectively destroying fibroid tissue while leaving the surrounding uterine tissue viable. This leads to shrinkage of fibroid tissue and a reduction of symptoms experienced by the patient within as early as one-month post-procedure.
Is fibroid myolysis clinically proven?
Several studies have looked into the effects of myolysis on uterine fibroid size and symptom severity, however, because there are so many methods for myolysis, no overarching study has researched them all. One study in 2010 looked at the efficacy of transvaginal ultrasound-guided RF myolysis in 69 women and found that fibroid volume was reduced by 74% at 12 months post-procedure with a significant reduction in bleeding symptoms.² Another study of 22 women looked at the viability of percutaneous microwave ablation of fibroids, finding similar results.³ The consensus amongst most clinical trials has been that myolysis provides an effective alternative to surgical treatments for fibroid symptom management.
How does myolysis compare to other treatment options?
Myolysis for uterine fibroids is not without its risks. A concern with many of the treatments for fibroid removal or destruction is their effect on future fertility and pregnancies. As fibroid tissue is destroyed with myolysis, scar tissue may form in the endometrium (the inner lining of the uterus) or in the myometrium (the muscular component of the uterus). Because myolysis causes tissue destruction without repair, the uterus may not be able to withstand the stress of a pregnancy. The size and location of the fibroid along with which energy source is chosen determines the risk and amount of scar tissue formation. While some studies have had some participants achieve successful pregnancies, some have also seen pregnancy complications such as uterine rupture.²⁻⁴ Because of this, the safety of the procedure for future pregnancy has not yet been established and women planning future pregnancies may want to look into other options such as myomectomy or uterine artery embolization.
However, for those without pregnancy plans, myolysis may provide an effective, minimally invasive alternative to other surgical options for symptomatic fibroids.
Is myolysis fibroid treatment right for me?
Myolysis for uterine fibroids is not a perfect treatment, however, it can provide a reduction in symptoms for women experiencing abnormal bleeding because of their fibroids. Depending on your specific symptoms, fibroid characteristics, and future plans for pregnancy, myolysis may be right for you. Talk to a fibroid specialist about your treatment options, and familiarize yourself with which one may be best for you.
 Zupi, E., Sbracia, M., Marconi, D., Munro, M.G. (2006) Myolysis of uterine fibroids: Is there a role? Clinical Obstetrics and Gynecology 49(4): 821-833.
 Kim, CH., Kim, SR., Lee, H., Kim, SH., Chae, HD., Kang, BM. (2010) Transvaginal ultrasound-guided radiofrequency myolysis for uterine myomas. Human Reproduction 26(3): 559-563.
 Yang, Y., Zhang, J., Han, Z., Yu, M., Ma, X., Zhou, H., Hao, Y., Zhao, Y., Dong, X., Ge, H. (2014) Ultrasound-guided percutaneous microwave ablation for submucosal uterine fibroids. Journal of Minimally Invasive Gynecology 21: 436-441.
 Bergamini, V., Ghezzi, F., Cromi, A., Bellini, G., Zanconato, G., Scarperi, S., Franchi, M. (2005) Laparoscopic radiofrequency thermal ablation: a new approach to symptomatic uterine myomas. American Journal of Obstetrics and Gynecology 192: 768-773.