Rare case of postpartum hemorrhage caused by rupture of a uterine artery pseudoaneurysm 3 months after Cesarean delivery

When postpartum hemorrhage occurs it is usually immediately following or several hours or days after delivery, and it almost always takes place within 6 weeks1, 2. Rupture of a uterine artery pseudoaneurysm subsequent to a Cesarean section is a rare cause of postpartum hemorrhage3, 4, and delayed postpartum hemorrhage from a pseudoaneurysm may be misdiagnosed as hypermenorrhea. Here we present an extremely rare case of massive postpartum hemorrhage 3 months after a Cesarean section that was successfully treated using selective uterine artery embolization (UAE). A 24-year-old woman, gravida 1, para 1, delivered a healthy infant via emergency Cesarean section at a local clinic in October 2007. Arterial hemorrhaging from the left lower uterine incision occurred during the operation and the artery was ligated with silk thread immediately and completely. The patient's postoperative and postpartum course was unremarkable, with the first menstruation in early December. On January 4, 2008, she was admitted to the same clinic with massive and continuous vaginal bleeding and received blood transfusions for shock. Since the bleeding stopped spontaneously after 5 days, she was diagnosed with hypermenorrhea and prescribed low-dose contraceptive pills. However, massive vaginal bleeding started again on February 1, and she was transported by ambulance to our hospital on February 5 with persistent hemorrhaging. Examination revealed hypotension, tachycardia and anemia. B-mode and color Doppler ultrasonography showed a cystic lesion in the left wall of the lower uterus (Figure 1a) but no retained placental fragments or pathological findings in the uterine cavity. Longitudinal color Doppler ultrasonography showed a blood-filled cystic structure with mosaic flow pattern (Figures 1b and c). After administration of intravenous fluids and four units of red blood cell concentrate, three-dimensional computed tomography (3D-CT) with an intravenous contrast agent showed a 2-cm enhanced lesion in the left parauterine region with a surrounding low-density area consistent with a pseudoaneurysm. Angiograms, with access through the right femoral artery, revealed focal extravasation from a branch of the left uterine artery (Figure 2), and this artery was successfully embolized using absorbable gelatin sponge pledgets (Gelfoam, Pfizer Inc., New York, NY, USA). Ultrasonographic findings on admission: gray-scale ultrasound image showing a cystic lesion (arrow) in the lower left wall of the uterus (a) and color Doppler ultrasound images showing turbulent arterial flow within the cystic lesion in the longitudinal (b) and transverse (c) views. Note the presence of the parent artery in (c). Non-selective pelvic arteriography showing a pseudoaneurysm (arrow) at the branch of the left uterine artery (a), superselective angiogram obtained using a microcatheter in the branch revealing a 2-cm pseudoaneurysm (arrow) (b) and late-phase internal iliac artery angiogram taken post-embolization showing complete occlusion of the left uterine artery and the pseudoaneurysm (c). The patient experienced minimal vaginal bleeding during the following 3 days and was discharged 1 week after the procedure. Normal menstruation resumed after 3 months, with normal 3D-CT scan results obtained at the 3-month follow-up visit. Pseudoaneurysms can be detected using Doppler ultrasound, appearing as blood-filled cystic structures5. Duplex Doppler ultrasound shows turbulent arterial flow, while color Doppler imaging shows arterial flow swirling in different directions and at different velocities within the pseudoaneurysm, with colors varying according to the degree of turbulence6. Arterial embolization has been used successfully in the management of postoperative, postabortion and postpartum intractable bleeding7. Advantages include high (90–95%) success rates, low complication rates, no surgical risks and preservation of fertility8. In conclusion, in this case we found color Doppler ultrasonography to be useful in diagnosing a uterine artery pseudoaneurysm as the cause of a late postpartum hemorrhage, which was treated successfully by UAE. Thus, when a pseudoaneurysm is suspected following color Doppler ultrasound and a subsequent CT scan, angiography and UAE are recommended. E. Hayata*, H. Matsuda*, K. Furuya*, * Department of Obstetrics and Gynecology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan