Uterine arteriovenous malformations (AVMs) are a rare cause of abnormal uterine bleeding (1). They are vascular anomalies involving pathological connections between and arteries and veins which can form secondary to surgery, trauma, pathology and/or pregnancy in a previously healthy uterus (2). There are currently no consensus diagnostic criteria or treatment guidelines for acquired uterine AVMs (3), and little is known about them in an Australian context. The objective of this retrospective audit was to describe the presentation, diagnosis, management and outcomes of women with acquired uterine AVMs at The Royal Women’s Hospital, Parkville.
All cases of acquired uterine AVM diagnosed by ultrasound and/or magnetic resonance imaging (MRI) from 2010 – 2016 were included. Imaging reports were searched for women who met inclusion criteria, and 18 cases were identified. Data were collected from electronic databases and paper medical records. Central tendency was expressed as median ± range. Bivariate analyses were performed using an Independent Samples Mann-Whitney U or two-tailed Fisher’s Exact Test with a significance level of p<0.05.
The rate of acquired uterine AVM diagnosis was found to have increased from 2011 to 2015, and decreased from 2015 to 2016. Included women had a median age of 29.2 years, gravidity of two and parity of one. The most common event prior to acquired uterine AVM development was surgical termination of pregnancy (n=6). Two women were diagnosed after caesarean section. All women presented with per vaginal bleeding and all were initially diagnosed with ultrasound. Eight women underwent MRI. There was no significant relationship between the peak systolic velocity of acquired uterine AVMs and subsequent management, serum haemoglobin, or clinical outcome. Women were managed expectantly (n=7) with methotrexate (n=1), or with uterine artery embolisation (n=9). Eleven women underwent angiography, and five were diagnosed with angiographic entities other than acquired uterine AVMs. Use of MRI was associated with accurate acquired uterine AVMs diagnosis at angiography, however this was not statistically significant (p=0.242). No variable was found to differentiate angiographic confirmed acquired uterine AVMs from other angiographic diagnoses.
These data indicate that rate of acquired uterine AVMs diagnosis at RWH is not continually increasing, and is not related to caesarean section rates. In our cohort, peak systolic velocity did not predict acquired uterine AVMs severity. These data suggest that while ultrasound is the mainstay of initial acquired uterine AVMs diagnosis and MRI is a useful adjunct imaging tool, angiography should remain the gold-standard of diagnosis.