Spontaneous rupture of an ovarian artery aneurysm complicated by postpartum hypertensive disorders of pregnancy after caesarean section: a case report and literature review

Abstract

Background

The spontaneous rupture of an artery aneurysm during the perinatal period is considered a serious complication associated with the physiological alteration by pregnancy and delivery. The rupture of an ovarian artery aneurysm is rare and leads to rapid retroperitoneal hemorrhage. Here, we report one case complicated by postpartum hypertensive disorder of pregnancy associated with massive bleeding into retroperitoneal cavity by the spontaneous rupture of ovarian artery aneurysm after caesarean section, and reviewed previous literature.

Case presentation

A 41-year-old Japanese woman was referred to our hospital four days after undergoing cesarean delivery because of hemorrhagic shock with abdominal and right flank pain. Contrast-enhanced computed tomography revealed a large retroperitoneal hematoma. Angiography showed a ruptured right ovarian artery aneurysm, anastomosing with a dilated uterine artery. She was successfully treated with transcatheter arterial embolization. She was diagnosed with postpartum hypertensive disorder of pregnancy 3 days after the embolization.

Conclusion

The rupture of ovarian aneurysm can occur during the perinatal period, although it has not been widely understood among obstetricians. Multiparity and hypertensive disorder of pregnancy might be risk factors for the rupture of an ovarian aneurysm. Early diagnosis and therapy, such as transcatheter arterial embolization in preparation for an emergency laparotomy, are crucially important for the management of this fatal disease.

Background

The spontaneous rupture of artery aneurysms such as the intracranial arteries, aorta, splenic artery, renal artery, and ovarian artery aneurysms (OAAs) during the perinatal period is considered as a serious complication associated with the physiological alteration by pregnancy and delivery [1]. If pregnant women have such artery aneurysms, the optimal mode of delivery is also debating even now. The formation and rupture of an OAA has not been widely understood among obstetricians. Only 23 cases have been reported in previous literature from 1963 to 2022, therefore obstetricians may not pay enough attention to this disease [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23]. All cases have involved multiparas, and the mechanisms of formation and rupture were reportedly related to hemodynamic and hormonal alterations during pregnancy. Ruptured OAAs initially present with abdominal pain without genital bleeding. Owing to the ubiquity of postpartum abdominal pain, therefore it is difficult to distinguish a sign of rupture from the general afterpain of caesarean section (CS). A ruptured OAA is a fatal disease, leading to rapid retroperitoneal hemorrhage. The abdominal pain is progressive, and the vital signs of patients progress into a shocked state. The treatment of ruptured OAA is laparotomy or transcatheter arterial embolization (TAE), which has been preferred in recent reports. Here, we report the case of a patient complicated by postpartum hypertensive disorder of pregnancy (HDP), who had spontaneous rupture of an OAA after undergoing CS and was successfully treated via TAE. Furthermore, published case reports involving related cases were also reviewed to improve clinical insights into this kind of this disease.

Case presentation

A 41-year-old Japanese woman, gravida 2, para 1, gave birth to a healthy baby girl, weighing 2902 g, by elective CS owing to a previous CS in the obstetrics general clinic. There were no surgical complications, and 414 g of blood was lost. She had a history of two myomectomy surgeries, CS 2 years prior, and postpartum HDP during her first childbirth. She had no history of HDP during pregnancy. At 4 days following the CS, severe abdominal pain and right flank pain were noted. She had a hemoglobin level of 8.8 g/dL, blood pressure of 67/40 mmHg, and pulse rate of 104 bpm. She was transferred to another hospital for further examination and treatment. Two units of red blood cells (RBCs) and fresh frozen plasma (FFP) were transfused. Contrast-enhanced computed tomography (CT) of the abdomen and pelvis confirmed a large retroperitoneal hematoma, measuring 18 × 13 × 11 cm, surrounding her right kidney (Fig. 1A). The contrast media extravasated into the retroperitoneum (Fig. 1B). Three-dimensional CT revealed the right ovarian and uterine artery aneurysms (Fig. 2). This hospital was not equipped with an intensive care unit, making laparotomy infeasible; therefore, massive blood transfusion as the only available treatment option. The patient was referred to our emergency department for TAE. A total of 8 units of RBC and 10 units of FFP were administered during the transfer.

Fig. 1

Contrast-enhanced computed tomography image of the abdomen and pelvis. A A massive hematoma measuring 18 × 13 × 11 cm surrounding her right kidney. B Dilated right ovarian artery (arrow)

Fig. 2 

Three-dimensional computed tomography images. Three-dimensional computed tomography shows the aneurysms of the right ovarian artery (transverse arrow) and uterine artery (vertical arrow)

On admission, she had a pulse rate of 108 bpm and blood pressure of 87/46 mmHg. Physical examination revealed muscle guarding pain and a lower abdominal bulge. She had a hemoglobin level of 8.5 g/dL, platelet count of 1.87 × 10⁶/μL, international normalized ratio of 1.01, and fibrinogen of 181 mg/dL. The interventional radiology team was consulted regarding the embolization of the ovarian and uterine arteries.

Angiography was immediately initiated. During the procedure, the patient’s blood pressure dropped to 70 mmHg and her pulse disappeared. The patient was immediately intubated. Following tracheal intubation, the patient’s vital signs stabilized, and angiography was safely resumed. On angiography, extravascular leakage of the contrast medium from the right ovarian artery, a pseudoaneurysm, and an anastomosis with a dilated uterine artery in the periphery were noted (Fig. 3A, B). Selective embolization of the right ovarian artery was performed using n-butyl-2-cyanoacrylate. Although the uterine artery did not exhibit extravasation, it was embolized using gelatin sponge particles to prevent rebleeding of the right ovarian artery through collateral blood flow. Upon completing TAE, 16 units of RBC and 22 units of FFP were transfused (including in the previous hospital).

Fig. 3

Angiography. Extravascular leakage of contrast medium from the right ovarian artery with a pseudoaneurysm (arrow A). Anastomosis with a dilated uterine artery in the periphery (arrow B)

Then, 1 day after embolization, the patient was extubated. Her antibiotics were upgraded to sulbactam/ampicillin, and the hemoglobin level and size of the hematoma were monitored. The patient’s hemoglobin level stopped decreasing after 2 days. Three days after the embolization, the patient’s systolic blood pressure rose and plateaued in the 160 mmHg range. She was diagnosed with postpartum HDP and was treated with nifedipine, an antihypertensive medication. The patient was discharged 17 days after embolization, and her hemoglobin level returned to 12.1 g/dL.

Discussion

The spontaneous rupture of an OAA is not widely understood, although reports of ruptured aneurysms during pregnancy of intracranial arteries and the aorta have been comparatively common. There have only been 22 reports (23 cases) of spontaneous pregnancy-related rupture of an OAA in English literature from 1963 to 2022 (Table 1) [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23]. The age of the patients ranged from 23 to 41 years (median 35 years). Among patients whose obstetric history was available, all were multigravida (23 cases), including seven grand multiparas (29.2%), defined as mothers who have given birth five or more times. There were 20 vaginal deliveries (83.3%) and four CS cases (16.7%). The CS rate is not significantly different from the worldwide CS rate (21.1% from 154 countries [24]); therefore, it is difficult to suggest whether vaginal delivery or CS is the optimal mode of delivery for pregnant women who has already know OAAs. The aneurysm occurred on the left side in 11 cases and on the right in 13 cases. There were no noted differences related to the laterality of the rupture. In 20 out of 24 cases (83.3%), the ruptures occurred during the postpartum period. Specifically, the ruptures occurred within 5 days after delivery in 19 cases (95%). The most frequent clinical manifestations included abdominal and flank pain in 22 cases (91.7%) owing to retroperitoneal hematoma formation. Since abdominal pain commonly presents during puerperium including after CS, it is likely to be underestimated in the absence of active genital bleeding. In the past, ruptured OAAs were treated via laparotomy [2,3,4,5,6,7,8, 10, 12,13,14]. However, most cases have been recently managed via TAE [9, 11, 15,16,17,18,19,20,21,22,23]. TAE is performed using gelatin sponge, coil or n-butyl-2 cyanoacrylate (NBCA) [25]. In this case, coil isolation was difficult because the vessels before and after the OAA were small and tortuous. NBCA was used to prevent rebleeding from the aneurysm.

Table 1 Reported cases of pregnancy-related spontaneous rupture of ovarian artery aneurysm

The mechanisms of the formation and rupture of OAAs were theoretically owing to hemodynamic and hormonal alterations during pregnancy. The increased cardiac output and total blood volume owing to the uterine blood demand during pregnancy increases mechanical forces on the vessel walls [1, 5]. The increased estrogen and progesterone levels influence arterial wall remodeling, and promote fibromuscular dysplasia of the tunica media and fragmentation of the elastic fibers [1]. These increase the likelihood of aneurysm formation. These alterations have been observed in successive pregnancies, and all previous cases involved multiparas. Rupture of uterine artery aneurysms may also occur during the peripartum period [26]. The patient in our case presented with ovarian and uterine artery aneurysms. Uterine artery pseudoaneurysm occurs after traumatic delivery or surgery, such as CS or myomectomy [27, 28]. In the present case, the uterine artery aneurysm likely resulted from the history of CS and myomectomy, as well as the hemodynamic and hormonal changes during pregnancy. OAA ruptures were typically detected later than uterine artery aneurysm ruptures because it caused sudden hemorrhagic shock without warning signs, such as genital bleeding.

In addition, hypertension was a reported risk factor for the rupture of an OAA [29]. Inflammatory activity of the vessel wall and endothelial dysfunction are the cause of abdominal aortic aneurysm formation and expansion [30, 31]. Because endothelial dysfunction and intravascular inflammation trigger preeclampsia [31, 32], HDP may also contribute to the formation of aneurysms and rupture. In our case, the patient developed severe HDP after delivery, which indicates a potential preexisting vascular endothelial dysfunction, and likely contributed to the formation of aneurysms of ovarian and uterine artery and its rupture.

The present case showed that retroperitoneal hematomas can be diagnosed via contrast-enhanced CT, and their location can be identified via angiography. In addition, tracheal intubation was required to stabilize the patient’s vital signs during angiography. When managing hemodynamically unstable patients, the vital signs and laboratory parameters should be closely monitored during embolization, and an emergency laparotomy should be prepared.

Conclusion

The rupture of OAA with massive bleeding into a retroperitoneum can occur without typical symptoms after delivery, although it is rare and has not been widely understood among obstetricians. The primary symptom is the flank pain and sudden hemorrhagic shock without genital bleeding during the peripartum period. Multiparity and HDP might be risk factors for the rupture of an OAA. Early diagnosis and therapy, such as TAE in preparation for an emergency laparotomy, are crucially important for the management of this fatal disease.