uterine arteriovenous malformation
Uterine arteriovenous malformations (UAVM) result from the formation of multiple arteriovenous fistulous communications within the uterus without an intervening capillary network.
The presentation can vary. UAVMs can cause life-threatening massive bleeding in young women. Uterine bleeding is the major presenting symptom in AVMs. As these malformations are less common after menopause, post-menopausal bleeding is rarely seen. Congestive heart failure secondary to a vascular steal syndrome can be a less common clinical manifestation with a large UAVM.
A UAVM consists of a proliferation of vascular channels with fistula formation and an admixture of small, capillary-like channels. The size of these vessels can vary considerably. They are classified as congenital or acquired. The latter is more common and is often described as a uterine arteriovenous fistula.
Congenital UAVMs tend to have multiple feeding arteries, a central nidus (a tangle of vessels with histologic characteristics of both arteries and veins), and numerous large draining veins .
Acquired or traumatic uterine AVMs represent multiple small arteriovenous fistulas between intramural arterial branches and the myometrial venous plexus . They typically represent a single artery joining a simple vein.
Acquired UAVMs disease is associated with conditions such as :
- multiple pregnancies
- previous surgery
- dilation and curettage
- termination of pregnancy
- cesarean section
Gray-scale sonographic appearances can be non-specific and can have a range of manifestations including areas of subtle myometrial inhomogeneity, tubular spaces within the myometrium, an intramural uterine, endometrial or cervical mass like region or sometimes as prominent parametrial vessels . The extent of the mass effect is however minimal.
Typically shows serpiginous/tubular anechoic structures within the myometrium with low resistance (RI ~0.2-0.5), high-velocity flow pattern on color Doppler interrogation.
MR imaging allows one to confirm the diagnosis of uterine AVM non-invasively. Multiple serpentine flow-related signal voids are typically seen in the uterine wall, endometrial cavity, and parametrium on T1 and T2 weighted images. Contrast-enhanced dynamic MR angiography can depict complex serpentine abnormal vessels that enhance as intensely as normal vessels and show early venous return .
Transcatheter arterial embolization is an excellent treatment option in selected cases.
On imaging appearances and if serum beta-HCG is elevated, consider:
- gestational trophoblastic disease (GTD)
- retained products of conception (RPOC): abnormality centered on endometrium rather than myometrium
History and etymology
They were first described by G Dubreil and E Loubat in 1926 .