Splenic artery aneurysm in obstetrical patients: A series of four cases with different clinical presentation and outcome

To describe four consecutive cases of splenic artery aneurysm (SAA) with different clinical patterns of presentation among obstetrical patients.

Alongside pregnancy, major risk factors for SAA rupture include portal hypertension, pancreatitis, liver transplantation, rapid growth, and aneurysm size greater than 2 cm. 11 Rupture of SAA in pregnancy is associated with an exceedingly high maternal and fetal mortality rate, reaching 75% and 95%, respectively. 1,9 Good perinatal outcomes can only be achieved by early diagnosis and prompt multidisciplinary treatment. Unfortunately, SAA rupture during pregnancy is often misdiagnosed because symptoms can be vague or similar to other more common obstetrical emergencies, such as ruptured extrauterine pregnancy, placental abruption, and uterine rupture. Therefore, high levels of awareness of and suspicion for this condition among obstetricians and other frontline staff is mandatory to improve preparedness and, subsequently, perinatal outcomes.
Here we describe four consecutive cases of SAA in obstetrical patients with different clinical presentation and outcomes.

| MATERIAL S AND ME THODS
This is a case-series including four consecutive cases of SAA diagnosed in pregnant or postpartum women at our University center between January 1998 and December 2020. Relevant clinical and radiologic data were obtained and herein described by reviewing paper and electronic medical records after obtaining patient's consent.
The study was approved by the Institutional Review Board of the University of Milan-Bicocca, Italy (protocol No. 236).

| Case 1 (year 1998)
A 29-year-old primigravida was admitted to our obstetrical Emergency Department (ED) at 29 weeks of pregnancy complaining of sudden onset of nausea associated with severe epigastric pain radiating to the back.
At the first clinical examination, vital signs were normal (blood pressure 125/85 mm Hg, heart rate 88 beats per minute [bpm]), abdominal palpation was regular and there were no uterine contractions. An ultrasound assessment showed normal fetal movements with a fetal heart rate of 140 bpm, and no free fluid in the abdomen. Thirty minutes after this first assessment, the patient became pale and distressed, started sweating profusely, and reported major pain in her left-sided abdomen. Vital sign assessment revealed blood pressure of 90/60 mm Hg and heart rate of 100 bpm. An ultrasound evaluation was immediately performed, which showed intrauterine fetal demise and blood clots overlying the fundus of the uterus.
Supposing placental abruption, the patient was transferred to the operating room for emergency cesarean delivery. After xipho-pubic incision of the abdomen, a massive intraperitoneal hemorrhage was identified. Also, a large retroperitoneal hematoma within the lesser sac and extending to the hilum of the spleen was found. There were no signs of placental abruption. With the intervention of a consultant vascular surgeon, the lesser sac was opened and a ruptured 18mm aneurysm of the splenic artery located at the splenic hilum was identified. Splenectomy was then performed. Estimated blood loss was 4300 mL; the patient was transfused with 10 units of red blood cells and 5 units of fresh frozen plasma. The postoperative course was uncomplicated and the patient was discharged on postpartum day 10.

| Case 2 (year 2018)
A 42-year-old woman presented at our outpatient Obstetrical Unit for her first scheduled visit at 14 weeks of pregnancy.
The obstetrical history included a previous first-trimester miscarriage following heterologous assisted reproductive technology in 2017. The current pregnancy was also conceived by heterologous assisted reproductive technology. In addition, the patient reported a hospital admission for pyelonephritis in 2016. By examining the discharge medical records, the obstetrician in charge found an abdominal computed tomography scan report describing the presence of an aneurysm of the splenic hilum of 16 mm, for which the patient did not receive any treatment at the time of diagnosis or follow-up assessment.
The woman was completely asymptomatic. An abdominal magnetic resonance imaging scan was immediately requested and confirmed a 16-mm SAA at the splenic hilum (Figure 1a,b). A multidisciplinary team including obstetricians, interventional radiologists, general surgeons, and anesthesiologists was assembled to appropriately assess potential management options. Considering the gestational age at diagnosis and the radiation exposure risk for the fetus in case of embolization, 12,13 the team opted for laparotomic resection of the aneurysm with concomitant splenectomy. 14 Laparotomy was performed at 19 +4 weeks of pregnancy, via an incision parallel to the left costal arch. The postoperative course was regular and she was discharged 12 days after surgery.
Pregnancy was complicated by gestational diabetes, which required diet and oral hypoglycemic agents to adequately control blood glucose levels. Fetal growth was regular. At 39 weeks of gestation, the patient went into spontaneous labor and delivered a healthy female baby of 2950 g. The postpartum course was uncomplicated and both the mother and the newborn were discharged on day 3 postpartum. Counseling on the need for vaccination against polysaccharide-encapsulated bacteria like pneumococci was performed before discharge.

| Case 3 (year 2018)
The third case is a 39-year-old woman at her first pregnancy who presented at our general ED at 29 weeks of pregnancy complaining of mild epigastric pain, fatigue, and general malaise. Pregnancy was complicated by gestational diabetes, which was adequately controlled by diet.
Upon ED arrival, the woman had hypotension (blood pressure 80/55 mm Hg) and mild tachycardia (heart rate 102 bpm). Her blood examinations showed anemia with a hemoglobin of 9.4 g/dl; electrocardiogram was normal. Abdominal palpation was negative for specific areas of tenderness. Three hours after the initial assessment, symptoms were partly improved with rest and intravenous hydration. She was then transferred to the obstetrical ED for evaluation of fetal well-being before discharge. During the transfer, maternal syncope occurred. A focused assessment with sonography for trauma (i.e. FAST) examination showed massive hemoperitoneum and fetal bradycardia. An emergency cesarean section was performed. During surgery, the woman experienced cardiac arrest, and notwithstanding cardiopulmonary resuscitation maneuvers, she expired in the surgery room. A male neonate of 1165 g was delivered. Apgar score was 1 at the first minute and 4 at the fifth minute; umbilical artery gas analysis at birth showed a pH of 6.75 with a Base Excess of −24.
The newborn was admitted to the neonatal intensive care unit and was managed with mechanical ventilation and surfactant administration. He was discharged after 55 days in good condition.
Autopsy examination of the woman confirmed that the cause of death was the rupture of a 17-mm SAA, located 4 cm from the splenic hilum.

| DISCUSS ION
Here we describe four consecutive cases of SAA with different clinical presentation and outcome diagnosed in obstetrical patients at our Institution over a 23-year period. Specifically, one case was completely asymptomatic and incidentally identified at the beginning of pregnancy, thus allowing for a planned surgical approach and a successful outcome. In turn, three SAA cases were unknown: two manifested with maternal collapse due to spontaneous rupture of the aneurysm during pregnancy, leading to maternal death in one case and stillbirth in the other, whereas one case presented with acute abdominal pain during the postpartum period and was successfully treated by angiographic embolization before rupture occurred.
Although the true prevalence of SAA and ruptured SAA in pregnant or postpartum women is still unknown, these conditions are considered very rare. 1,7,15 Over a two-decade period and 63 826 deliveries, we identified four cases of SAA in obstetrical patients, two In both our cases complicated by a two-stage SAA rupture in the third trimester (cases 1 and 3), this condition was not suspected before performing emergent surgery for maternal hemodynamic instability and intraperitoneal bleeding. In particular, placental abruption was hypothesized in case 1.
Before rupturing, SAA can be asymptomatic and incidentally diagnosed or manifest with non-specific upper abdominal symptoms, as occurred in our cases 2 and 4, respectively. Importantly, diagnosis of SAA before rupture allowed for multidisciplinary management and planned treatment, which have been reported as pivotal to markedly reduce maternal fatality rate. 2,3,18 Mortality rate rises from less than 3% for elective treatment to 75% for emergency intervention after rupture occurs, with a fetal mortality rate reaching 95%. 19,20 These high percentages are mostly the result of delayed diagnosis. 1,9,21 In our series of four SAA cases, there was one maternal death and one fetal demise, and SAA was not suspected in either.

F I G U R E 2
Computed tomography of abdomen with contrast shows a voluminous 3-cm aneurysm in the proximal third of the splenic artery (arrow) (a). The splenic artery aneurysm as seen in the splenic arteriography before embolization (b). Aneurysm was embolized by release of multiple detachable coils with the "sandwich technique" (arrows) and neck occlusion (arrowhead) (c). Postembolization splenic arteriography demonstrated complete exclusion of aneurysm sac and patency of distal splenic artery branches recanalized with collateral pathways through short gastric arteries (arrowhead) and pancreatic magna artery (arrow) (d) Clinical presentation of SAA can vary widely, so this should be taken into account in the diagnostic imaging process for pregnant and postpartum women. 1 In hemodynamically unstable patients with hemoperitoneum, ultrasonography should be the first imaging technique because it is rapidly available without removing the woman from the clinical arena; it is safe, non-invasive, and allows accurate assessment of the degree of intraperitoneal free fluid, thus identifying cases who may require laparotomy. 22 Importantly, this imaging can be performed by obstetricians as well as by adequately trained frontline healthcare professionals, without requiring a radiology consultation. 23,24 In addition, sonography performed by an obstetrician can provide information regarding the fetal status, the placenta, the uterus, and the adnexa, which can aid in the process of differential diagnosis. 1,17 Ultrasonography with color Doppler also represents the first imaging choice among hemodynamically stable women with vague symptoms. In this case, it should be performed by an expert radiologist and if inconclusive, due to bowel gas, advanced gestation, or small-sized vascular lesions, it should be followed by computed tomography or magnetic resonance imaging. 1 Computed tomography with contrast is the reference standard imaging to identify SAA because it allows precise definition of the size and location of the aneurysm and so allows adequate plan management. 14,25 However, potential fetal risks related to ionizing radiation and iodinated contrast material exposure contraindicates its use in favor of magnetic resonance imaging, if available, before 25 weeks of pregnancy. 12,13 Advanced imaging can also help in differentiating SAA from vein aneurysms. Although much rarer than SAA, splenic vein aneurysms (SVA) share similar etiology, presenting symptoms, complications, and management with SAA. 26 Also, high parity and advanced gestation represent substantial risk factors for rupture. As such, SVA and SVA rupture should always be included in the differential diagnosis of non-uterine abdominal pain and hemoperitoneum in pregnant and postpartum women. 27 Recently, updated guidelines for management of visceral artery aneurysms have been published. 14 Considering the substantial risk of rupture of SAA in the third trimester of pregnancy and the related exceedingly high fatality rates, these guidelines suggest that SAA diagnosed in asymptomatic or mildly symptomatic pregnant women should always be treated regardless of their size. Hence, the 2-cm cut-off previously used to decide for intervention is no longer valid.
Of note, both our cases of SAA rupture had a size smaller than 2 cm.
The guidelines also suggest treatment of SAA of any size in women of childbearing age because of the risk of rupture. 14 Management options include endovascular treatment with angiographic embolization and surgery with ligation or resection of the aneurysm and potential concomitant splenectomy. 3,28,29 Gestational age at diagnosis and SAA localization are key elements in guiding the choice of the therapeutic approach. 1,30,31 The updated guidelines on management of visceral artery aneurysms suggest a preference for an endovascular approach in electively managed cases, except for distal SAA adjacent to the hilum of the spleen, which should preferably be approached with open surgical techniques. 14 Arterial embolization can be considered after 25 weeks of pregnancy to avoid potential problems related to fetal radiation exposure 12,13 and only for SAA located in the proximal or middle third of the splenic artery to prevent splenic abscesses due to ischemia. 14

CO N FLI C T O F I NTE R E S T
The authors have no conflicts of interest.

DATA AVA I L A B I L I T Y S TAT E M E N T
Data sharing is not applicable to this article as no new data were created or analyzed in this study.

AUTH O R CO NTR I B UTI O N S
IC contributed to conception of the work, acquisition and interpretation of data, and drafting of the first version of the manuscript. SO contributed to interpretation of data, and drafting of the first and re-