Visceral artery aneurysm: an unusual cause of abdominal pain

Abstract

Visceral artery aneurysms (VAAs) are uncommon with an approximate incidence of 0.01%–0.2%. Gastroduodenal artery (GDA) aneurysm is a rare subtype of these uncommon visceral aneurysms that can be fatal if ruptured. We present a case of a 58-year-old Caucasian woman with a VAA and a large haematoma arising from an actively bleeding GDA. While patients with VAA may remain asymptomatic, with some of the aneurysms found incidentally during imaging, they may also present with abdominal pain, anaemia and possible multiorgan failure which may be fatal.

Background

Visceral artery aneurysms (VAAs) are uncommon and may present with a wide range of clinical manifestations. The objectives of our case presentation are to raise awareness of VAAs/pseudoaneurysms and to understand the risk factors, clinical features, complications and management of this condition.

Case presentation

A 58-year-old Caucasian woman with a medical history significant for asthma, Graves’ disease and multiple sclerosis presented to the hospital for severe shortness of breath and wheezing of 1-day duration. Her symptoms were low-grade fever, chills and dry cough. Imaging of the chest showed multifocal multilobular pneumonia and she was started on intravenous antibiotics. At the time of admission, the patient reported vague right upper quadrant abdominal pain, about 5/10 in severity and associated with nausea. The pain had been present for a few days prior to admission and was tolerable. On admission, the patient was stable with a temperature of 36.3°C, heart rate of 84 beats per minute, respiratory rate of 22/min, blood pressure of 105/70 mm Hg and had normal oxygen saturation on room air. Her haemoglobin was 109 g/dL, and her white cell count was 6.85 ×10⁹/L.

On day 2 of the admission, the pain increased in severity, and physical examination revealed a soft, non-distended abdomen, right upper quadrant tenderness without rigidity and bowel sounds were positive. Abdominal ultrasound revealed a right upper quadrant mass at the mesenteric root. To further evaluate this mass, CT of the abdomen with oral and intravenous contrast was ordered which revealed a right-sided mid-abdominal peripancreatic aneurysm of 3.2 cm in diameter with a large bleeding haematoma arising from the gastroduodenal artery (GDA) (figures 1 and 2). The patient was in no distress; her blood pressure was 97/49 mm Hg with a heart rate of 78 beats per minute. The patient was transferred to the intensive care unit for close observation and management. Her haemoglobin dropped to 66 g/L and the patient was transfused with three units of packed red blood cells. A multidisciplinary team of internal medicine, general surgery and interventional radiology was involved in providing care for this patient. An emergent mesenteric digital subtraction angiography (DSA) revealed jejunal branch pseudoaneurysm and irregularity of the vessel with extravasation into a large haematoma (figure 3). This was successfully embolised with a combination of coils and n-Butyl cyanoacrylate (BCA) glue. The procedure was well tolerated, and there was a steady improvement in the patient’s condition with no further drop in her haemoglobin on the following days after the procedure. The patient was discharged home 6 days later and was advised to follow-up in 2 weeks.

Figure 1.

Coronal section CT scan of the abdomen with oral and intravenous contrast showing right-sided mid-abdominal peripancreatic aneurysm with large haematoma.

Figure 2.

Transverse section CT scan of the abdomen with oral and intravenous contrast showing right-sided mid-abdominal peripancreatic aneurysm with large haematoma.

Figure 3.

Digital subtraction angiography showing jejunal branch pseudoaneurysm and irregularity of the vessel with extravasation into a large haematoma.

Five days after initial discharge, the patient presented to the emergency room with refractory vomiting. Upper gastrointestinal (GI) endoscopy revealed significant stenosis of the first part of the duodenum. CT angiogram of the abdomen showed a stable 14 cm haematoma that surrounded the first part of the duodenum. The patient was treated with a CT-guided percutaneous drain placement which led to relief of her symptoms. The patient was discharged home with instructions to discontinue the drain in an out-patient setting. Four months post discharge, patient came for a follow-up visit and was doing very well.

Investigations

• Abdominal ultrasound revealed right upper quadrant mass at the mesenteric root.

• CT abdomen with oral and intravenous contrast revealed right-sided mid-abdominal peripancreatic aneurysm of 3.2 cm in diameter with large actively bleeding haematoma arising from the GDA.

• An emergent mesenteric DSA revealed jejunal branch, pseudoaneurysm and irregularity of the vessel with extravasation into a large haematoma.

Treatment

An emergent mesenteric CT angiogram revealed a jejunal branch pseudoaneurysm and irregularity of the vessel with extravasation into a large haematoma. This was successfully embolised with a combination of coils and n-BCA glue. The procedure was well tolerated and the patient’s condition improved steadily over the following days with consistently stable vital signs and improvement of her haemoglobin level to 124 g/L. The patient was discharged home on the 6th day after the procedure in a stable medical condition and was advised to return in 2 weeks post discharge for follow-up.

Outcome and follow-up

Five days after her initial discharge, the patient presented again with repeated vomiting. Upper GI endoscopy revealed significant stenosis of the first part of the duodenum. CT angiogram of the abdomen showed a stable 14 cm haematoma surrounding the first part of the duodenum. A CT-guided percutaneous drain placement led to relief of symptoms. The patient was discharged home with instructions to remove the drain in an outpatient setting. Four months post discharge, the patient returned for a follow-up visit and was doing very well and in stable condition.

Discussion

VAAs are uncommon with a reported incidence of approximately 0.01%–0.2%¹ and may present with a wide range of clinical symptoms. The most common arterial sites that may develop aneurysms are the splenic artery, hepatic artery, superior mesenteric artery (SMA) and the coeliac artery in descending order of frequency.² GDA aneurysms represent only 1.5% of all VAAs² and are considered extremely rare.³ Like all VAAs, GDA aneurysms can be classified, depending on the aetiology, into true aneurysms or pseudoaneurysms. True aneurysms are attributed to vessel wall abnormalities from atherosclerosis, while pseudoaneurysms occur after trauma or inflammation,⁴ such as pancreatitis, autoimmune disorders, vascular intervention, laparoscopic cholecystectomy and liver transplantation.⁵ In a review of literature that extended over a period of 25 years, pancreatitis was the most common condition associated with GDA aneurysms.⁶ Our patient with a pseudoaneurysm did not have any obvious secondary causes, and further work-up is warranted to understand the aetiology of the aneurysm. It has been hypothesised that interruption of the blood supply from stenosis or occlusion of the coeliac axis increases blood flow in the GDA through the pancreaticoduodenal arteries from the SMA, which could be an aetiological factor for the development of the aneurysms.^{7 8} Our patient’s emergent angiography showed critical stenosis (occlusion) of the coeliac artery and this could have led to the development of the aneurysm because of increased blood flow through the GDA.

Aneurysm rupture with gastrointestinal haemorrhage was found to be the most common presentation of the reported cases in the literature³ with the highest mortality rate (close to 21%) coming from rupture into the duodenum.⁹ These patients present with haematemesis, melena and shock.¹⁰ Bleeding into the retroperitoneal and intraperitoneal beds occurs less frequently¹¹ and could lead to gastric outlet obstruction¹² or other non-specific symptoms like nausea, vomiting or jaundice due to the pressure effect from the haematoma¹³ as seen in our patient. Abdominal pain is the second most common presentation³ which could be present with or without rupture. Other patients may remain asymptomatic and aneurysms may be found incidentally due to the widespread use of CT scans.

The gold standard investigation is visceral angiography. With a sensitivity of 100%, it helps with both diagnostic and therapeutic purposes by allowing endovascular embolisation.¹⁴ Contrasted CT scan is a non-invasive test with a sensitivity of 67% that helps to outline vascular anatomy when planning surgical repair.¹⁵

Rupture of a VAA poses a serious life-threatening situation. Fatality can occur in up to 40% of ruptured aneurysms.¹⁶ It is crucial to have a high sense of clinical suspicion and widen the differential diagnosis of abdominal pain with anaemia to include unusual causes like VAA. The risk of rupture and the choice of intervention is variable and the decision is made on a case-by-case basis, depending on the stability of the patient, other comorbidities and the location of the aneurysm.² GDA pseudoaneurysms have a higher risk of rupture regardless of their morphology, making proactive treatment necessary, irrespective of the size of the aneurysm.¹⁷ The rupture rate for GDA aneurysms is high with an associated mortality rate of 40%,³ therefore, treatment of pseudoaneurysms is mandatory. Endovascular trans-catheter coil embolisation is the most popular intervention⁷ since it is less invasive and is a good alternative to open surgical intervention despite the potential risk of visceral ischemia and embolisation to other organs.¹⁸ In our case, the patient was treated with endovascular coil embolisation with glue which was very well tolerated with no complications after the intervention. Open surgical intervention is reserved for cases with active bleeding associated with haemodynamic instability or cases where initial endovascular intervention was not effective to control the bleeding.¹⁹ There is no consensus about the optimal management for VAAs, and current management strategies suggested in the literature are based on observational studies and case series.¹⁷

Intra-abdominal hypertension may occur due to increased intra-abdominal or retroperitoneal volume, which may affect visceral perfusion, cardiac output, respiratory and renal function, and cause multiorgan failure and death.²⁰ A very important aspect to consider after endovascular repair is the rise in the intra-abdominal pressure secondary to the haematoma which may lead to acute compartment syndrome which may lead to a detrimental outcome. Abdominal decompression is recommended when the intra-abdominal pressure is >20 mmHg or if acute compartment syndrome develops in some patients.

Conclusion

VAAs, especially GDA aneurysms, are rare. They can be asymptomatic and only found incidentally during imaging, but their rupture is serious and may be fatal. Physicians should have a high clinical suspicion, and a multidisciplinary approach is required to manage this condition promptly and avoid complications.

Learning points.

• Visceral artery aneurysms are uncommon and may be found incidentally during imaging.

• Gastroduodenal artery aneurysms represent only 1.5% of these uncommon visceral aneurysms.

• Consider including this condition in the differential diagnosis when patients present with unexplained abdominal pain, anaemia with or without haemodynamic instability.

• Rupture of the aneurysm is a life-threatening condition with a reported fatality rate of 40%.

• The gold standard diagnostic investigation is visceral angiogram as it allows for immediate intervention with trans-catheter coil embolisation.