Splenic artery pseudoaneurysm: Challenges of non-invasive and endovascular diagnosis and management

Spontaneous rupture of a mycotic splenic artery pseudoaneurysm secondary to histoplasmosis: a case report

BACKGROUND

A splenic artery pseudoaneurysm is a rare pathology that occurs mainly secondary to pancreatitis, abdominal trauma, peptic ulcers, pancreatic and gastric cancers, and infections. It is best diagnosed using computed tomography angiography and typically treated using endovascular embolization and, in some cases, open or laparoscopic surgery. In this report, we present a case of a ruptured mycotic splenic artery pseudoaneurysm containing Histoplasma capsulatum, which to our knowledge is the first case to report a mycotic splenic artery pseudoaneurysm of this nature.

CASE PRESENTATION

We report a case of a 42-year-old white male with past medical history of Hepatitis C and IV drug abuse who presented to the Emergency Department with a 24-h history of severe diffuse abdominal pain. He was tachycardic and peritonitic on exam. Work-up demonstrated leukocytosis and lactic acidosis. Computed tomography of the abdomen and pelvis with intravenous contrast showed hemoperitoneum and active extravasation of contrast from the splenic artery into the splenic hilum, associated with a surrounding hematoma measuring 5.3 × 5.0 cm, concerning for ruptured splenic artery pseudoaneurysm. The patient was taken emergently for exploratory laparotomy, where a large intraperitoneal hematoma was evacuated. A ruptured splenic artery pseudoaneurysm was identified, isolated, and controlled, followed by completion splenectomy. Final pathology demonstrated a 3.0 × 1.3 × 0.3 cm pseudoaneurysm wall and a 14 × 9.5 × 5.5 cm spleen containing multiple necrotizing granulomata positive for the presence of Histoplasmosis species. The patient recovered appropriately and was discharged on post-operative day five.

CONCLUSIONS

This case demonstrates a successful approach to a ruptured mycotic splenic artery pseudoaneurysm resulting in a positive outcome. It is a unique case as it highlights, to our knowledge, the first report of splenic artery aneurysm secondary to Histoplasma capsulatum infection. This report helps further the understanding of the pathophysiology as well as the natural history of mycotic splenic pseudoaneurysms.

Endovascular Stent-Graft Repair of True and False Aneurysms of the Splenic Artery

OBJECTIVE

In treatment of aneurysms (SAAs) and pseudoaneurysms (SAPs) of the splenic artery, endovascular coil embolization is the approach most commonly used as it is minimally invasive and safe. However, it carries a significant rate of primary failure (up to 30%) and might be complicated by splenic infarction. The use of stent grafts might represent a valuable alternative when specific anatomical criteria are respected. We report a comprehensive review on technical and clinical outcomes achieved in this setting. Methods: We performed a comprehensive review of the literature through the MedLine and Cochrane databases (from January 2000 to December 2023) on reported cases of stenting for SAAs and SAPs. Outcomes of interest were clinical and technical success and related complications. The durability of the procedure in the long-term was also investigated. Results: Eighteen papers were included in the analysis, totalling 41 patients (n = 20 male 48.8%, mean age 55.5, range 32-82 years; n = 31, 75.6% SAAs). Mean aneurysm diameter in non-ruptured cases was 35 mm (range 20-67 mm), and most lesions were detected at the proximal third of the splenic artery. Stent grafting was performed in an emergent setting in n = 10 (24.3%) cases, achieving immediate clinical and technical success rate in 90.2% (n = 37) of patients regardless of the type of stent-graft used. There were no procedure-related deaths, but one patient died in-hospital from septic shock and n = 2 (4.9%) patients experienced splenic infarction. At the last available follow-up, the complete exclusion of the aneurysm was confirmed in 87.8% of cases (n = 36/41), while no cases of aneurysm growing nor endoleak were reported. None of the patients required re-intervention during follow-up. Conclusions: When specific anatomical criteria are respected, endovascular repair of SAAs and SAAPs using stent grafts appears to be safe and effective, and seems to display a potential advantage in respect to simple coil embolization, preserving the patient from the risk of end-organ ischemia.

Spontaneous Resolution of Recurrent Pancreatitis After Splenic Artery Pseudoaneurysm Stent Placement

Acute pancreatitis (AP) is a relatively common condition most often secondary to excess alcohol consumption, choledocholithiasis, medications, or hypertriglyceridemia. In rare cases, AP can result in a secondary splenic artery pseudoaneurysm (SAP). SAPs are a rare yet serious medical complication and are often under-diagnosed as they are usually asymptomatic. However, rupture and subsequent hemorrhage of SAPs pose life-threatening risks. This case involves a 72-year-old male presenting with portal vein thrombosis and recurrent episodes of AP with persistently elevated levels of lipase of no apparent etiology over a 6-month period. As patient history and pertinent test results ruled out all common causes of recurrent AP, the etiology of his AP remained unknown. After an SAP rupture and emergency treatment with an endovascular stent, the patient's recurrent AP spontaneously resolved, and lipase returned to normal levels. This case represents a yet-to-be-reported etiology of AP in which the proximal nature of the SAP with its associated inflammatory response to the pancreas resulted in intermittent AP. The lack of any other reasonable explanation for the etiology of the patient's recurrent AP along with the absence of any additional episodes after the treatment of his SAP supports this diagnosis. The findings of this case could prove useful to clinicians with patients suffering from recurrent episodes of AP with no known etiology and suggest that a potential undiagnosed SAP should be investigated further.

A ruptured splenic artery aneurysm treated by transcatheter arterial embolization using n-butyl cyanoacrylate-Lipiodol-Iopamidol

N-butyl cyanoacrylate, one of embolic materials, is usually used as a mixture with Lipiodol (N-butyl cyanoacrylate-Lipiodol mixture). N-butyl cyanoacrylate-Lipiodol-Iopamidol was developed by adding a nonionic iodine contrast agent (Iopamiron) to N-butyl cyanoacrylate-Lipiodol mixture. N-butyl cyanoacrylate-Lipiodol-Iopamidol has lower adhesiveness than N-butyl cyanoacrylate-Lipiodol mixture and the ability to form a single large droplet. We report the case of a 63-year-old man with a ruptured splenic artery aneurysm treated by transcatheter arterial embolization using N-butyl cyanoacrylate-Lipiodol-Iopamidol. He was referred to the emergency room because of sudden onset of upper abdominal pain. A diagnosis was established using contrast-enhanced computed tomography and angiography. Emergency transcatheter arterial embolization was performed, and the ruptured splenic artery aneurysm was successfully embolized using a combination of coil framing and N-butyl cyanoacrylate-Lipiodol-Iopamidol packing. This case demonstrates the usefulness of a combination of coil framing and N-butyl cyanoacrylate-Lipiodol-Iopamdol packing for the embolization of aneurysms.

Splenic Artery Pseudoaneurysms: The Role of ce-CT for Diagnosis and Treatment Planning

Splenic artery pseudoaneurysm (PSA) is a contained vascular wall lesion associated with a high mortality rate, generally related to pancreatitis, trauma, malignancy, iatrogenic injury, and segmental arterial mediolysis. Computed tomography angiography allows us to visualize the vascular anatomy, differentiate a PSA from an aneurysm, and provide adequate information for endovascular/surgical treatment. The present review reports on the main state-of-the-art splenic artery PSA diagnosis, differentiating between the pros and cons of the imaging methods and about the endovascular treatment.