The successful detection of postpartum unruptured vaginal pseudoaneurysm using ultrasonography: a case report

We report the first case of the successful detection of postpartum unruptured vaginal pseudoaneurysm using power- and pulsed-Doppler ultrasonography after delivery.

A 38-year-old primiparous Japanese woman had a vaginal laceration with pulsatile bleeding after delivering by vacuum extraction. Transvaginal ultrasonography of the repaired vaginal wall showed an 18 × 20 mm hematoma within which a 6 × 7 mm pulsating anechoic mass was detected. Power-Doppler ultrasonography showed blood flow signals in the anechoic mass. Arterial waveforms detected in pulsed-Doppler mode were suggestive of unruptured pseudoaneurysm. Careful monitoring with contrast-enhanced computed tomography showed an increase in the size of the pseudoaneurysm on the fourth postpartum day. On the sixth postpartum day, massive vaginal bleeding occurred. Emergency angiography revealed strong staining with extravasation from the left vaginal artery, confirming the diagnosis of pseudoaneurysm. Embolization for hemostasis was successfully performed.

As far as we know, our case is the first in which an unruptured vaginal pseudoaneurysm was diagnosed using ultrasonography. The differential diagnoses of pseudoaneurysm are arteriovenous malformations including arteriovenous fistula. This case had the typical ultrasonographic patterns of pseudoaneurysm in which the presence of one or two cystic masses in B-mode and color- and/or power-Doppler flow signals was demonstrated along with high-resistance arterial flow waveforms in pulsed-Doppler mode. Sequential examinations of contrast-enhanced CT showed ongoing development of the pseudoaneurysm. In retrospect, we could have performed angiography for embolization when the unruptured pseudoaneurysm was diagnosed, or at the latest when ongoing development of the pseudo-aneurysm was recognized, irrespective of whether symptoms were present.

Ultrasonography is a non-invasive and clinically useful modality in the differential diagnosis of pseudoaneurysm. Contrast-enhanced computed tomography with or without ultrasonography can be useful for sequential monitoring of the size of unruptured pseudoaneurysms.