Cryosurgery as an Alternative Treatment for Menorrhagia and Uterine Fibroids

Nearly 80% of all women may suffer from uterine fibroids (leiomyomas) and/or menorrhagia, which is a condition where the uterus walls bleed abnormally. The vast majority of women whose symptoms are strong enough to require treatment obtain a hysterectomy. Other treatment options which are less invasive than hysterectomy include thermal therapies such as thermal ablation or cryosurgical removal of tissue. This project numerically evaluates the efficacy of a liquid-nitrogen-based cryotherapy for the treatment of uterine fibroids. A bioheat transfer model was utilized which included both the effects of blood perfusion and the impacts of liquid-to-solid phase change. An upper limit on the cooling rate was obtained by simulating a direct contact between the probe tip and the inner lining of the uterus. Calculations were carried out for a one-minute treatment duration with 720 calculation nodes which spanned the thickness of the uterine wall. Results obtained from the calculations allowed a determination of the cooling rate at each nodal location within the tissue. Based on data obtained from previous cell-survival studies, it was found that necrosis would occur within the tissue up to a depth of approximately 5.8 mm.