Spontaneous Drainage of Paravalvular Abscess Diagnosed by Transesophageal Echocardiography Peter Giannoccaro, MD, FRCPC,' Kathy J. Ascah, MD, FRCPC, Randall A. Sochowski, MD, FRCPC, Kwan-Leung Chan, MD, FRCPC, and Terrence D. Ruddy, MD, FRCPC, Ottawa, Ontario, Canada
Paravalvular abscesses, which occur in up to 30% of cases of native valve endocarditis, are being detected with increasing frequency with the use of transesophageal echocardiography. Abscesses of the mitral aortic intervalvular fibrosa have been described but only in association with native or prosthetic aortic valve endocarditis. We describe a patient with native mitral valve endocarditis complicated by an abscess in the fibrosa. A 51-year-old diabetic man presented with Staphylococcus aureus mitral valve endocarditis. A transesophageal echocardiographic study done 8 days after admission revealed two large masses at the base of the anterior mitral leaflet with extension into the fibrosa consistent with a paravalvular abscess that was not detected by precordial echocardiography. A repeat transesophageal echocardiographic study done 20 days after admission showed spontaneous drainage of the abscess and a subsequent fistula between the left atrium and left ventricle. This case highlights the important role that transesophageal echocardiography has in suspected and known cases of endocarditis. Its major advantage of delineat4J.g posterior cardiac structures allowed accurate diagnosis and serial evaluation of this previously unreported complication of endocarditis. (JAM Soc EcHOCARDIOGR 1991;4:397-400.)
The evaluation of patients with suspected infective endocarditis has been greatly improved through the use of transesophageal echocardiography. 1 With this technique, smaller vegetations and complications of infective endocarditis such as leaflet tears or perforations, ruptured chordae tendineae, fistulas, aneurysms, and paravalvular abscesses are readily identified. Paravalvular abscesses occur in up to 30% of cases of native valve endocarditis2 and are detected with higher frequency by transesophageal echocardiography, compared with the conventional precordial approach. 3 Abscess of the mitral-aortic intervalvular fibrosa has previously been reported in association with endocarditis of prosthetic aortic valves. Abscesses in this area may lead to pseudoaneurysm From the University of Ottawa Heatt Institute. Reprint requests: Kathy J. Ascah, MD, University of Ottawa Heart Institute, 1053 Carling Ave., Ottawa, Ontario, Kl Y 4E9 Canada. 'Research Fellow of the Heart and Stroke Foundation of Canada. 27/1126574
formation, which have significant potential for fistula development. 4 . 6 In this report we describe a patient with native mitral valve endocarditis complicated by an abscess of the fibrous trigone and detected by transesophageal echocardiography. Spontaneous drainage of the abscess into the left ventricle and subsequent fistula formation was demonstrated by serial transesophageal echocardiographic studies. CASE REPORT
A 51-year-old man was admitted to hospital with fever and leukocytosis. He had a 10-year history of insulin-dependent diabetes mellitus complicated by proliferative retinopathy, nephropathy with endstage renal disease requiring continuous ambulatory peritoneal dialysis, peripheral vascular disease with a below-the-knee amputation, and symptomatic coronary artery disease. On the day before admission he became febrile and anorexic. At the time of admission he appeared acutely ill with a temperature of 40° C. 397
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A, Transesophageal echocardiographic four-chamber view reveals two large masses (vegetations) at base of anterior leaflet of mitral valve (arrow). B, Closeup of four-chamber view. Arrow indicates echolucent space in the area of the mitral-aortic intervalvular fibrosa consistent with abscess cavity. L4., Left atrium; RA, right atrium; LV, left ventricle; R V, right ventricle.
Figure 1
A new apical pansystolic murmur (grade II/VI) was detected, but no peripheral stigmata of infective endocarditis were present. The white blood cell count was 28.9 x 109 /L (28,900 mm 3 ) with 95% neutrophils. The electrocardiogram showed normal sinus rhythm with right bundle branch block and old inferior wall myocardial infarction. Chest radiography revealed mild cardiomegaly and vascular redistribu-
tion. Antibiotic treatment (penicillin and cefuroxime) was started before results of blood cultures for a presumptive diagnosis of pneumonia. On the fourth hospital day the patient became bradycardic. The electrocardiogram showed complete heart block with a junctional escape of 45 beats/ min. He was transferred to the intensive care unit for monitoring and insertion of a temporary transvenous
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Figure 2 A, Closeup four-chamber view shows the abscess cavity in the mitral aortic intervalvular fibrosa, which has drained and is in continuity with the left ventricle (LV)_ B, Fourchamber view with color flow mapping. Arrow indicates flow into abscess cavity. C, Line diagram of A. Lined areas represent normal cardiac structures, dotted area correlated with the vegetation and abscess. Arrow indicates the communication with the left ventricle. LA, Left atrium; RA, right atrium; R V, right ventricle.
pacemaker. Worsening pulmonary edema required intubation and more vigorous dialysis. Two of two blood cultures grew coagulase-positive staphylococcus and his antibiotic therapy was changed to vancomycin. He improved and was extubated after 3 days of ventilation. Precordial and transesophageal studies were performed 8 days after admission with a HewlettPackard 77020 (Hewlett-Packard Co., Andover, Massachusetts) equipped with a 2.25 MHz transducer for the precordial and a 5 MHz transesophageal probe for transesophageal echocardiographic study. The precordial echocardiogram showed thickening of the anterior leaflet of the mitral valve. Transesophageal echocardiography revealed two large masses at the base of the anterior leaflet of the mitral valve with extension into the fibrous trigone consistent with a paravalvular abscess not discernible
precordially (Figure l). The aortic valve exhibited sclerotic changes, but no vegetations were seen. Precordial echocardiography was nondiagnostic but transesophageal echocardiography confirmed both the presence of infective endocarditis and the complication of an abscess in the fibrous trigone. Serious consideration was given to surgical intervention, but the prohibitive operative risk made medical therapy the preferred option. Repeat transesophageal echocardiography was performed 20 days after admission and showed spontaneous drainage of the paravalvular abscess with communication of the cavity with the left ventricle (Figure 2). The patient remained stable and vancomycin therapy was continued for 8 weeks. A permanent pacemaker was inserted after completion of the antibiotic course. A third transesophageal echocardiographic
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the anterior mitral leaflet led to abscess formation in the mitral-aortic intervalvular fibrosa. Conduction abnormalities, found in up to 10% of native valve endocarditis, can also develop, as was seen in this case. Involvement of this area with abscess can lead to pseudoaneurysm formation and to fistulous communications with the left atrium. 4 · 6 It may also rupture into the pericardia! space causing tamponade or pyohemopericardium. In this case, the abscess drained spontaneously into the left ventricle with the subsequent formation of a left ventricular to left atrial fistula. This case demonstrates the superiority of transesophageal echocardiography compared with precordial echocardiography for delineating the anatomy of the mitral valve and its surrounding structures. It allowed initial accurate diagnosis of vegetations involving the mitral valve and in serial monitoring during medical therapy revealed subsequent complications. This suggests that transesophageal echocardiography should be used early and in the follow-up of patients undergoing medical treatment for infective endocarditis, which will allow for early detection and surgical intervention for complications that develop. Figure 3 A, Transesophageal echocardiographic closeup four-chamber view. The left atrial aspect of the cavity has degenerated to create a fistula between the left ventricle (arrow) and left atrium. B, Color flow mapping illustrates significant mitral regurgitation through the fistula (area of blue-green turbulence in left atrium). LA, Left atrium; RA, right atrium; LV, left ventricle.
study, done before discharge, documented breakdown of the left atrial side of the false aneurysm, creating a fistulous communication between the left ventricular outflow tract and left atrium associated with moderate to severe mitral insufficiency (Figure 3). After 3 weeks at home, the patient required readmission for worsening heart failure. Despite aggressive medical therapy, the patient died. No autopsy was performed.
DISCUSSION
Paravalvular abscess formation is a serious and often lethal complication of infective endocarditis. 5 ·6 Staphylococcus (coagulase positive) is often associated with abscess formation. The aortic valve is usually involved, leading to secondary infection of the fibrous trigone. 4 ·5 In the present case a vegetation of
We thank Laureen Lanthier and Louise Funke for editorial assistance. REFERENCES l. Mugge A, Daniel WG, Frank G, Lichtlen PG. Echocardiog-
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