Mass General Hospital
JANUARY 2011
ISSUE 33

 
 
Fever in a Young Man with Mechanical Valves
John P. Lichtenberger III, MD, Hector M. Medina, MD, MPH, Brett W. Carter, MD, James Woo, MD, Vikram Venkatesh, MD, Suhny Abbara, MD, and Wilfred Mamuya, MD, PhD
 
  Clinical History
A 27-year-old man presented with fevers and new-onset chest pain. His history was notable for intravenous drug abuse, with prior mechanical aortic and mitral valve replacement secondary to endocarditis. A transesophageal cardiac ultrasound (TEE) was consistent with prosthetic valve endocarditis of his mechanical aortic valve, with a paravalvular abscess. A cardiac CT was requested to further delineate the extent and anatomical relationship of the abscess with the coronary arteries prior to a consideration of repeat cardiac surgery.

Findings
TEE imaging (Figure 1A and 1B) was consistent with a paravalvular abscess involving the inter-valvular fibrosa and extending almost circumferentially around the mechanical prosthetic aortic valve, with turbulent flow during systole. Cardiac CT (Figure 2A and 2B) confirmed the presence of a large and complex paravalvular abscess that communicated with the left ventricular outflow tract. The largest collection was between the aortic valve and right ventricular ouflow tract, with additional collections situated between the right atrial appendage and aorta, and between the origin of the left main coronary artery and myocardium.


Figure 1A

Figure 1B

Figure 2A

Figure 2B

(Rollover images to enlarge)

Figure 1A: Short axis TEE image of the aortic valve showing a large paravalvular abscess (*) extending nearly circumferentially around the aortic valve.

Figure 1B: Color Doppler short-axis TEE view of the aortic valve demonstrating a significant amount of paravalvular regurgitation (arrows).

Figure 2A: Multiplanar-reformatted short axis cardiac CT image of the mechanical aortic valve show contrast collections (*) around mechanical aortic valve consistent with paravalvular abscesses.

Figure 2B: Three chamber cardiac CT image of the mechanical aortic valve show contrast collections (*) around mechanical aortic valve consistent with paravalvular abscesses.


Discussion
Paravalvular abscesses, valve dehiscence, and paravalvular leaks are consequences of prosthetic valve endocarditis, most commonly affecting the aortic valve. Coagulase-negative staphylococci and S. aureus account for the majority of cases. Peri-annular extension of infectious endocarditis confers high mortality, particularly in prosthetic valve disease, and urgent surgical treatment is usually indicated. TEE is the current gold standard in evaluating such cases. Initial results have demonstrated that cardiac CT compares favorably to TEE and has added value in pre-operative planning and exclusion of coronary artery disease prior to surgery. Our patient had CT evidence of abscess extension surrounding the origin of his left main coronary artery, and his surgical risk was deemed prohibitive in light of recurrent IV drug use. His cultures were positive for Candida parapsilosis. He was treated with a six-week course of antifungals followed by life-long suppressive therapy and continues to do well three years after this episode.


 
 
REFERENCES
1. Rohmann S, Erbel R, Mohr-Kahaly S, Meyer J. Use of transoesophageal echocardiography in the diagnosis of abscess in infective endocarditis. Eur. H. Journal 1995; 16 (Supplement B), 54-62.
2. Entrikin DW, Ntim WO et al. Endocarditis with perforation of a bicuspid aortic valve as shown by cardiac-gated multidetector computed tomography. JCCT 2007; 1:177-180.
3. Feuchtner GM, Stolzmann P et al. Multislice computed tomography in infective endocarditis: comparisons with transesophageal echocardiography and intraoperative findings. JACC 2009; 53:436-44.
4. Lentini S, Monaco F et al. Aortic valve infective endocarditis: could multi-detector CT scan be proposed for routine screening of concomitant coronary artery disease before surgery? Ann Thorac Surg 2009; 87:1585-87.
   

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Editors:
Suhny Abbara, M.D.
MGH Department of Radiology
Wilfred Mamuya, M.D., Ph.D.
MGH Division of Cardiology

Phone: 617-726-5954