Successful pregnancy after the noninvasive management of uterine arteriovenous malformation

Abstract

A 22-year-old woman, gravida 2, para 0, showed massive vaginal bleeding and was admitted to our institution. She had persistent vaginal bleeding for 4 weeks after a secondary artificial abortion at 14 weeks’ gestation. When she was presented to our hospital, evaluation included negative urine hCG, and hemoglobin of 10.7 g/dl. Vaginal examination showed no uterine enlargement and no adnexal mass, but vaginal bleeding and some bloody coagula was recognized. Transvaginal ultrasound showed multiple tubular anechoic spaces without mass effect in the myometrium from the left anterior wall to the fundus. As dysfunction of uterine contraction due to retained products of conception, or trauma following artificial abortion was suspected, she was administered 0.2 mg of intramuscular methylergometrine maleate and 0.5 mg/day of oral methylergometrine maleate for 5 days. Vaginal bleeding decreased soon after the intramuscular injection, and she was discharged the next day with no vaginal bleeding. One week later, she was admitted again to our hospital with massive vaginal bleeding. Her hemoglobin was 6.9 g/dl. She was given only 0.5 mg/day of methylergometrine maleate orally for 7 days, which stopped the vaginal bleeding immediately. Her hemoglobin value subsequently rose by oral administration of iron alone. Percutaneous transfemoral angiography showed a 3×2 cm hypervascular mass which looked like nidus in the left uterine wall (Fig. 1), and Color Doppler ultrasound revealed a mosaic pattern in the same area of the uterine wall, which was compatible with uterine AVM. Approximately one month later, angiography was performed again for embolization, but the procedure was not carried out because of an obvious reduction in the size of the lesion. Color Doppler ultrasonography also demonstrated the decreased size of the mosaic pattern area. After discharge, follow-up Color Doppler examinations showed no signs of abnormal findings, nor any abnormal bleeding. She conceived 8 months after her previous pregnancy. Her pregnancy progressed quite normally, and ultrasound evaluation showed normal fetal growth. At 38 weeks’ gestation, a normal male infant weighing 3504 g was born by cesarean section. During the operation, no abnormality was found in the uterine myometrium by ultrasound or macroscopy. Digital subtraction angiography of the internal iliac artery demonstrates irregular, hypervascular vessels of the left uterine artery. Uterine AVM is a very rare condition and hysterectomy or embolization has been applied in its treatment. Conservative management, such as embolization, is preferable for the preservation of reproductive capability. To our knowledge, there have been ten reported cases of pregnancies after embolization of uterine AVM and one case of the noninvasive management of uterine AVM with methylergometrine maleate in 1999. We report here on a case of successful management of uterine AVM with methylergometrine maleate which was followed by full term pregnancy. Uterine AVMs are either congenital or acquired. Congenital uterine AVMs are considered to be the result of anomalous differentiation or developmental arrest in the primitive capillary plexus. The causes of acquired uterine AVMs are usually secondary to uterine neoplasm such as choriocarcinoma, curettage, infection and so on. It is important to diagnose it correctly and to start appropriate treatment promptly, because uterine AVM often causes life-threatening massive and persistent vaginal bleeding. Although interventional radiology has been used to diagnose uterine AVM preoperatively, the use of noninvasive Color Doppler ultrasound has increased over the past few years. The mainstay for management of uterine AVM has been hysterectomy or the embolization of uterine arteries. A few years ago, however, Flynn and Levine reported on the successful noninvasive management of a uterine AVM using methylergonovine maleate (1). Our report is the second case where AVM has been managed with methylergometrine maleate. Recently, Timmerman and colleagues reported nine cases diagnosed as having uterine vascular malformations using color Doppler imaging, and some of these cases have shown spontaneous regressions (2). They advocated the possibility of a new pathological entity, named subinvolution of the placental bed that was different from true AVM. In order to determine whether methylergometrine maleate has therapeutic action on uterine AVM, more case data must be collected. The mechanism of disappearance of uterine screw arteries, after normal delivery, may hold the clue to explaining the course of our case. The possibility that we observed spontaneous regression of uterine AVM on its own still remains. It is not proven that methylergometrine maleate has definite effectiveness on uterine AVM. Trying methylergometrine maleate does seem worthwhile, however, when massive vaginal bleeding calms down. We are grateful to L. Saza for helpful advice on the manuscript.