Uterine artery pseudoaneurysms are very dangerous and should be diagnosed as soon as possible. Potential causes include vascular injury following abortion, curettage, and pelvic surgery. Traumatic injury to the vessel wall causes wall incompetence and hemorrhage leading to a pseudoaneurysm. In this case, both two-dimensional and Doppler ultrasound scans were useful in detecting the pseudoaneurysm.
In two-dimensional ultrasonographic images, a pseudoaneurysm manifests as a hypoechoic mass and is thereby not easily differentiated from a hematoma or a true aneurysm. Color Doppler ultrasonography was helpful in this case as it demonstrated turbulent arterial flow with a to-and-fro pattern, connected to a parent artery by a narrow neck in the pseudoaneurysm. Blood flow into the mass during systole and away from the mass during diastole can be explained by the pressure gradient between a distended high-pressure pseudoaneurysm and the low pressure in the artery during diastole . A true aneurysm manifests as a color-coded fusiform dilation of the parent artery and spectral analysis can demonstrate a typical arterial flow pattern. A simple hematoma does not reveal any color signal caused by turbulent blood flow. The wall of a pseudoaneurysm is formed by a peripheral thrombus. In this case, decidual tissue and chorionic tissue were also found in the wall. We diagnosed the pseudoaneurysm by ultrasonography at the day after curettage. Therefore, we think it is necessary for patients to undergo a Doppler ultrasound examination as a required postoperative investigation especially in cases of cesarean scar pregnancy. Repeating these examinations several times over a short time period might allow early diagnosis of a pseudoaneurysm, when it is still small in size.
In this case, the pseudoaneurysm was located in the cesarean scar. The wall of the pseudoaneurysm was very thin and at high risk of rupture, it should have been treated as rapidly as possible. In such cases, endovascular treatment is often the first-line therapy. Embolization can be achieved with coils, stents and injectable liquids [9, 10], and offers the potential of preserving fertility for the patient. However, in the literature, the pseudoaneurysms treated successfully by this method were only 0.6–3.5 cm in diameter .
If time allows, and if embolization is not an option, intra-operative ligation of the pseudoaneurysm feeding vessels should be attempted prior to resorting to hysterectomy, especially in patients with low parity . Ligation of the ascending branch of the uterine artery may successfully stop postabortal hemorrhage in approximately 90% of patients.
Another possible treatment method was direct injection of thrombin into the pseudoaneurysm , but no further experience has been reported in the literature. Thus, we lack knowledge on the scope of possible complications associated with this procedure, such as subsequent arterial thrombosis or allergic responses.