Giant Celiac Artery Pseudoaneurysm in a Case of Chronic Pancreatitis: A Rare Case Report With Literature Review

Introduction

Pancreatic pseudoaneurysms are relatively rare complications of chronic pancreatitis, which can be asymptomatic or may present as an acute emergency in the form of a spontaneous gastrointestinal or intraperitoneal hemorrhage. ¹ These pseudoaneurysms involve peri-pancreatic visceral arteries with the splenic artery being most commonly affected (50%), followed by gastroduodenal arteries (10-15%) and pancreaticoduodenal arteries, superior mesenteric, left gastric, and celiac artery. ² Due to their inherent instability, untreated pseudoaneurysms may insidiously progress and can rupture spontaneously, leading to significant fatality. ³ Hence, early diagnosis with relevant radiological investigations and management are essential in decreasing both mortality and morbidity of the patient. This case report describes the clinical manifestations, diagnosis, and management of a 35-year-old man, who presented with features of hypovolemic shock and was found to have a bleeding celiac artery pseudoaneurysm with radiological features of chronic pancreatitis.

Case Report

A 35-year-old gentleman presented to the emergency department with complaints of intermittent episodes of upper abdominal pain for 1 year, which aggravated over a day. He also had multiple episodes of non-bilious vomiting, generalized fatigue, and light-headedness. The pain was of pricking type, progressive in nature, radiating to the back, and aggravated by food intake. He was a known alcohol addict for the last 15 years, and the previous alcohol binge was 1 week back. He did not seek any medical advice for the earlier episodes of abdominal pain. Clinical examination showed severe pallor, tachycardia (120/min), hypotension (60/40), and severe epigastric tenderness and guarding. A nasogastric tube was placed on suspicion of a gastrointestinal hemorrhage, which did not show any evidence of bleed. A digital rectal examination also did not show any evidence of melena.

After resuscitating him with adequate crystalloids and blood products, a duplex ultrasound was done which revealed a 4.7 x 2.6 cm saccular aneurysm arising from abdominal aorta in the background of chronic calcific pancreatitis. Contrast-enhanced Computed Tomography (CECT) showed evidence of bleeding celiac artery pseudoaneurysm in a background of chronic pancreatitis (Figure 1). Well-formed collaterals were seen from the superior mesenteric artery to the hepatic artery via the gastroduodenal artery and other smaller unnamed collaterals, with evidence of splenic artery thrombosis and splenic infarction, which was suggestive of a long-standing pseudoaneurysm. Portal vein adequacy was also ascertained by the CECT abdomen in the portal venous phase. Digital Subtraction Angiography (DSA) was done through the right common femoral access under local anesthesia and using a 5Fr diagnostic catheter the celiac artery was catheterized and DSA was done (Figure 2). A large pseudoaneurysm was seen just at the origin of the celiac trunk with a very short stump. The celiac trunk was super selectively catheterized using 2.7fr Progreat® microcatheter but endovascular coiling was deferred due to the larger size of the aneurysm and stent-graft was unavailable. Due to continued hemodynamic instability due to rupture of pseudoaneurysm, the procedure was abandoned and proceeded for an open repair. With ongoing resuciatation he was brought immediately to the operating room, and celiac artery ligation was done through a thoracoabdominal retroperitoneal approach as a life-saving procedure. CT angiography on postoperative day 7 showed a completely obliterated aneurysmal sac with no evidence of contrast filling (Figure 3). He was discharged on the 10th postoperative day with counseling for alcohol deaddiction and a plan of pancreatic drainage surgery in the future.

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Figure 1.

Images from the CT angiography done at presentation. A, 3-Dimensional volume reconstruction of the CT angiography. B and C, Axial sections. Blue arrows—celiac artery pseudoaneurysm; yellow arrows—dilated main pancreatic duct; red arrows—pancreatic calcifications.

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Figure 2.

Digital subtraction angiography of the celiac artery pseudoaneurysm.

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Figure 3.

Postoperative CT angiography images. A, 3-Dimensional volume reconstructed image showing ligated celiac trunk with well-formed collaterals from the superior mesenteric artery to the hepatic artery (green arrow) via the gastroduodenal artery (white arrow). B and C, Axial sections showing the absent celiac trunk with features of chronic pancreatitis. Yellow arrows—dilated main pancreatic duct; red arrows—pancreatic calcifications.

Discussion

Though pancreatic pseudoaneurysms can occur in 10% of patients with chronic pancreatitis, the celiac artery’s involvement is very rare.^4,5 A systematic search was made from the 3 databases PubMed, Ovid, and Google Scholar using the following MeSH (Medical Subject Headings) terminologies: “Pancreatitis, Chronic,” “Aneurysm,” “Aneurysm, False,” “Aneurysm, Ruptured,” “Celiac artery.” A manual search was also performed using the reference list of the selected publications. Although visceral artery pseudoaneurysms occurring due to chronic pancreatitis have been widely reported, the celiac trunk is the least common site to be involved. ⁶

A pseudoaneurysm differs from a true aneurysm in not having an actual arterial wall. Pseudoaneurysm is a hematoma, which is surrounded by fibrous tissue and which can enlarge or rupture. In pancreatitis, pseudoaneurysms form by the enzymatic destruction of the arterial walls due to the liberation of pancreatic enzymes like amylase, lipase, and protease or by an established pseudocyst eroding into a major artery. ⁷ Pseudoaneurysms can be asymptomatic or, more commonly, a dull epigastric discomfort or may present as an emergency in the form of acute gastrointestinal, intraperitoneal, or retroperitoneal hemorrhage, with mortality rates as high as 40%. ⁸

There are various investigations to screen and diagnose pancreatic pseudoaneurysms like duplex ultrasound, CECT, Magnetic resonance angiography (MRA), and DSA. Duplex ultrasound is the preferred modality for a screening of a small pseudoaneurysm. It may show a distinctive “Ying yang sign” which is the to-and-fro movement of blood from the neck into the pseudo aneurysmal sac. ⁹ In our patient, Duplex ultrasound detected a saccular aneurysm of size 4.7 x 2.6 cm arising from the abdominal aorta. CECT / CT angiography is a fundamental diagnostic tool that provides us details with high accuracy regarding the site, size, and extent of pseudoaneurysm and the involved artery and its adjacent effect on viscera. ¹⁰ The typical appearance in CECT is a well-defined mass with hyperdensity in the center due to contrast enhancement and relatively less density in the periphery due to the fibrous wall. ¹¹ 3D reconstruction can be done using volume rendering multiplanar techniques and helps pre-procedural planning and individualize the anatomy of arterial structures. ¹² The role of MRA is limited in emergency settings, as it is very time-consuming. It is helpful in elective cases in patients with contrast media anaphylaxis and renal failure. ⁴ DSA is an important adjunct in the diagnosis and follow-up with the advantage of providing therapeutic options along with giving other details regarding the site, size, and flow characteristics. ¹³ Emergency endovascular interventions have replaced surgical procedures with the added advantage of low postoperative complications and less morbidity and mortality. Endovascular options include embolization using coils or glue (cyanoacrylate), or a stent-graft placement, which excludes the aneurysm without losing the lumen of the artery. When such endovascular management fails or is unavailable, an urgent surgical intervention remains the only option. Surgical options include proximal arterial ligation with an aorto-hepatic bypass with arterial reconstructions or inter-positional graft with or without a pancreatic resection, depending on the location of the pseudoaneurysm.^14,15 In our case, only proximal celiac artery ligation was done as the pre-operative CT demonstrated collaterals between the common hepatic and superior mesenteric artery via the gastroduodenal artery along with other unnamed collaterals. During DSA selective injection of SMA was not tried due to cardiovascular collapse. In this patient, celiac artery ligation was done as a life-saving procedure, and collaterals were not looked at in order not to prolong any operative time. His postoperative liver function tests were normal, and there was neither evidence of liver abscess formation nor signs of liver failure. The authors recommend repeat CECT after 1-year follow-up.

Conclusion

A celiac artery pseudoaneurysm due to chronic pancreatitis, although uncommon, can result in life-threatening hemorrhage. It should be suspected as a possible complication in pancreatitis and pseudocyst. Unfortunately, many cases remain asymptomatic, and their initial presentation will be acute hemorrhage. Digital subtraction angiography is the gold standard investigation, providing a therapeutic option of coiling or stenting in the same setting. Failure or unavailability of an endovascular option requires urgent surgical intervention. Proximal arterial ligation may suffice to treat pancreatic pseudoaneurysm if good collaterals to the liver are present, as demonstrated by a pre-procedure CT.