P30.15: MRgFUS treatment of uterine leiomyoma to resolve acute urinary retention: a case report

Abstract

Acute urinary retention (AUR) is one of the rare complications associated with leiomyoma. Extrinsic compression of the urinary tract is considered the main cause of AUR that significantly affects women's quality of life. We describe a case of leiomyoma treated with MR guided focused ultrasound (MRgFUS) to resolve AUR. A 45-year-old premenopausal, nulliparous woman, who had undergone bladder catheterization at an emergency clinic because of two recent occurrences of AUR, visited our hospital complaining of AUR and heavy menstrual bleeding, and desiring uterus-preserving treatment. MRI showed a large intramural leiomyoma measuring 97.4 × 90.2 × 97.3 mm, with a volume of 425cc in the anterior myometrium, and two other small leiomyomas ≤20 mm in diameter near the fundus. The large leiomyoma, hypointensive on T2WI, was treated with MRgFUS with the use of ExAblate 2000 system (Insightec) and 1.5T-MRI (Signa, GE Healthcare) as separately reported. The treatment was completed without complications and the patient, discharged after one hour without a urinary catheter, was able to urinate normally and felt well with no adverse events. Of the large leiomyoma 66.8% was ablated. One week thereafter, however, the patient required a catheter again because of AUR and yielded 1000ml of urine at four in the morning. AUR recurred once in the following four months, but for over two years after the last episode, the patient has been free of voiding dysfunction. After MRgFUS, the massive menstrual bleeding decreased gradually as well, and the shrinkage ratio of leiomyoma measured on MR images reached 31.6, 43.1, 51.2, 55.7, 61.3 % at 6, 12, 18, 24, 30 months, respectively. The minimally invasive treatment with MRgFUS was effective in resolving AUR and in preserving the uterus despite two recurrences of AUR within first four months posttreatment, suggesting that the necrosis and softening of the leiomyoma reduced extrinsic compression of the urinary tract.