A Perforated Mitral Valve Aneurysm: A Rare but Serious Complication of Aortic Valve Endocarditis Resulting From a Regurgitant Jet Lesion

Abstract

Infective endocarditis has high morbidity and mortality rates. The aortic valve is most often affected in native valve endocarditis. Complications of aortic valve endocarditis range from local abscess and fistula formation, systemic complications secondary to thromboembolism and septic embolization, to congestive heart failure resulting from conduction system involvement and valve damage. A rare complication of aortic valve endocarditis is the occurrence of a 'jet lesion' on the mitral valve. Such a lesion, caused by an impinging regurgitant jet stream from a damaged aortic valve, can become directly and indirectly inoculated and evolve into a local infected aneurysm which might eventually rupture causing acute severe congestive heart failure and/or peripheral thromboembolism. We present the case of a 63-year-old man who presented with aortic valve endocarditis complicated by a perforated mitral valve aneurysm, congestive heart failure, and peripheral thromboembolism.

Endocarditis infecciosa por Streptococcus gordonii complicada con aneurisma mitral perforado y perforación de válvula aórtica: reporte de caso y revisión de la literatura

“…6 There are several mechanisms of MVA formation: in the presence of aortic valve IE, the jet lesion may result in secondary destruction of the mitral valve due to: A) the jet damaging the endothelial surface of the mitral valve, B) retrograde dissemination of bacteria, or C) the presence of neovessels (prominent in AMVL) which results in localized inflammation, valvulitis, protrusion of weakened MV into the left atrium cavity, and subsequently aneurysmal formation. 3,5,10 Respect retrograde dissemination might result from 1) direct contact between the aortic vegetation and the AMVL during diastole, known as «mitral kissing vegetations» when they exceed 6 mm in length, 2) secondary infection of the damaged endothelium by bacteria from regurgitation blood flow, or 3) local spread of the infection through the mitral-aortic intervalvular fibrosa. 5 Approximately two-thirds of MVAs rupture or perforate; the size of the aneurysm does not correlate with the risk of perforation; the AMVL is much more commonly involved than the posterior leaflet for unknown reasons.…”

“…3,5,10 Respect retrograde dissemination might result from 1) direct contact between the aortic vegetation and the AMVL during diastole, known as «mitral kissing vegetations» when they exceed 6 mm in length, 2) secondary infection of the damaged endothelium by bacteria from regurgitation blood flow, or 3) local spread of the infection through the mitral-aortic intervalvular fibrosa. 5 Approximately two-thirds of MVAs rupture or perforate; the size of the aneurysm does not correlate with the risk of perforation; the AMVL is much more commonly involved than the posterior leaflet for unknown reasons. 5 The echocardiographic appearance of MVA is characterized by a saccular bulge of the mitral leaflets that extends into the left atrium during systole and collapses during diastole.…”

“…5 Approximately two-thirds of MVAs rupture or perforate; the size of the aneurysm does not correlate with the risk of perforation; the AMVL is much more commonly involved than the posterior leaflet for unknown reasons. 5 The echocardiographic appearance of MVA is characterized by a saccular bulge of the mitral leaflets that extends into the left atrium during systole and collapses during diastole. 5,11 Other echocardiographic features vary from small saccular bulges, often challenging to identify due to vegetation, to large leaflet protrusions towards the left atrium, which may be associated with various degrees of mitral regurgitation and thrombosis.…”

“…MVA incidence in the setting of IE has decreased from approximately 3.5% to less than 0.3%. 5 Once MVA ruptures and severe mitral regurgitation with hemodynamic instability develops, immediate surgical intervention is required. 3,6 Streptococcus gordonii is an extremely rare cause of IE complicated with abscesses, fistulas, aneurysms, or valve perforation.…”

Accurate and Rapid Diagnosis of Complex Mitral Valve Aneurysm with Neoplasm via Real-time 3D Transesophageal Echocardiography

“…Although MVAs are clinically rare, the relevant literature has provided a comprehensive understanding of MVAs. MVAs are closely related to aortic valve infection, and in most cases, MVAs result from infective endocarditis [Kolluru 2020;Werner 2020;Moretti 2018;Tomsic 2016]. However, a few individual cases of MVA without infective endocarditis have been reported [Kim 2012].…”