CASE 17938 Published on 29.11.2022

Teaching Case

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Eric Han, Riya Bansal, Roozbeh Houshyar, Justin Glavis-Bloom

UCI Medical Center Department of Radiological Sciences, Building 1, 101 The City Dr S, Orange, CA 92868

Patient

44 years, male

Categories

Area of Interest Abdomen, Liver ; Imaging Technique MR, Ultrasound ;

No Procedure ; Special Focus Aneurysms ;

Show more Show less

View full case Show related cases Notify admin

Clinical History

A 44-year-old male with a history of methicillin-sensitive staphylococcus aureus endocarditis complicated by intracranial haemorrhage and septic splenic and renal infarctions presented with right upper quadrant (RUQ) pain. Laboratory values revealed elevated alkaline phosphatase (661 U/L), ALT (241 U/L), AST (277 U/L), direct bilirubin (2.7 mg/dL), and total bilirubin (4.6 mg/dL).

Differential Diagnosis List

Mycotic hepatic artery aneurysm

Mirizzi’s syndrome

Hepatic artery thrombosis

Vasculitis

Imaging Findings

RUQ ultrasound demonstrated non-shadowing intraluminal gallbladder material concerning for haemorrhage and mild intrahepatic biliary ductal dilation.

CT abdomen/pelvis with contrast demonstrated intraluminal gallbladder hyperdensity, mild biliary ductal dilatation, and a focal area of contrast density concerning for pseudoaneurysm at the porta hepatitis.

MRI abdomen with contrast demonstrated a focal area of arterial enhancement concerning for right hepatic artery mycotic pseudoaneurysm, intraluminal gallbladder T2 shading concerning for haemorrhage, and mild biliary ductal dilatation.

Abdominal angiography demonstrated a pseudoaneurysm primarily supplied by the right segment 4 hepatic artery and glue embolization of the segment 4 pseudoaneurysm was performed.

Discussion

Background

Mycotic aneurysms are dilations of the arterial wall due to an underlying infection. They are classically seen in patients with a history of infective endocarditis, intravenous drug use, or risk factors predisposing to bacteremia or bacterial inoculation [1]. The femoral, aortic, and intracranial vessels are commonly affected, but the visceral abdominal arteries also may be affected [2, 3]. Mycotic aneurysms carry a high mortality rate and require prompt diagnosis and treatment for patient survival [4].

Clinical Perspective

Patients who develop hepatic artery mycotic aneurysms may have clinical symptoms seen in other right upper quadrant pathologies. Common symptoms include fever, RUQ pain, and rarely a pulsatile mass in the right upper quadrant [5]. Patient history of intravenous drug use, infective endocarditis, immunosuppression, or a recent surgical procedure may help with the diagnosis [6]. Elevated liver enzymes, alkaline phosphatase, and bilirubin may be seen when mycotic aneurysms involve the hepatobiliary system [7, 8].

Imaging Perspective

Computed tomography and MRI are the most sensitive and specific radiologic modalities for diagnosing mycotic aneurysms. Imaging findings seen in mycotic aneurysms include perivascular contrast enhancement, intramural air collections, disruption of arterial wall calcifications, and saccular vessel wall with lobulated contours [6].

Outcome

The day after admission, the patient had a partial embolization of the segment 4 right hepatic artery pseudoaneurysm. His postoperative course was uncomplicated and he was discharged home from the hospital.

Teaching Points

Mycotic aneurysms may involve the visceral abdominal arteries and require prompt diagnosis and treatment for patient survival. CT and MRI are highly sensitive and specific modalities for detecting mycotic hepatic artery aneurysms.

Written informed patient consent for publication has been obtained.

References

[1] Stone JR, Bruneval P, Angelini A, et al. Consensus statement on surgical pathology of the aorta from the Society for Cardiovascular Pathology and the Association for European Cardiovascular Pathology: I. Inflammatory diseases. Cardiovasc Pathol. 2015;24(5):267-278. doi:10.1016/j.carpath.2015.05.001 (PMID: 26051917)

[2] Brown SL, Busuttil RW, Baker JD, Machleder HI, Moore WS, Barker WF. Bacteriologic and surgical determinants of survival in patients with mycotic aneurysms. J Vasc Surg. 1984;1(4):541-547. (PMID: 643614)

[3] Baddour LM, Wilson WR, Bayer AS, et al. Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications: A Scientific Statement for Healthcare Professionals From the American Heart Association [published correction appears in Circulation. 2015 Oct 27;132(17):e215] [published correction appears in Circulation. 2016 Aug 23;134(8):e113] [published correction appears in Circulation. 2018 Jul 31;138(5):e78-e79]. Circulation. 2015;132(15):1435-1486. doi:10.1161/CIR.0000000000000296 (PMID: 26373316)

[4] Huang YK, Chen CL, Lu MS, et al. Clinical, microbiologic, and outcome analysis of mycotic aortic aneurysm: the role of endovascular repair. Surg Infect (Larchmt). 2014;15(3):290-298. doi:10.1089/sur.2013.011 (PMID: 24800865)

[5] M. A. Abbas, R. J. Fowl, W. M. Stone et al., “Hepatic artery aneurysm: factors that predict complications,” Journal of Vascular Surgery, vol. 38, no. 1, pp. 41–45, 2003. (PMID: 12844087)

[6] W. K. Lee, P. J. Mossop, A. F. Little et al., “Infected (mycotic) aneurysms: spectrum of imaging appearances and management,” Radiographics, vol. 28, no. 7, pp. 1853–1868, 2008. (PMID: 19001644)

[7] N. N. Harlaftis and J. T. Akin, “Hemobilia from ruptured hepatic artery aneurysm: report of a case and review of the literature,” American Journal of Surgery, vol. 133, no. 2, pp. 229–232, 1977. (PMID: 299994)

[8] J. T. Stauffer, M. D. Weinman, and T. E. Bynum, “Hemobilia in a patient with multiple hepatic artery aneurysms: a case report and review of the literature,” American Journal of Gastroenterology, vol. 84, no. 1, pp. 59–62, 1989. (PMID: 2643298)

Case information