Ruptured pseudo-aneurysm of the mitral–aortic intervalvular fibrosa — A 3D transesophageal echocardiographic depiction

Abstract

Pseudo-aneurysm of the mitral–aortic intervalvular fibrosa (MAIVF) is a rare complication of native or prosthetic valve endocarditis. Good imaging is the key to successful diagnosis of this rare entity. This report describes a pseudo — aneurysm of the MAIVF rupturing into left atrium in a patient with double valve replacement with special reference to 3-dimensional transesophageal echocardiographic imaging.

<Learning objective: Transesophageal real-time 3-dimensional echocardiography provides useful information in understanding the anatomy of pseudo-aneurysm of mitral–aortic intervalvular fibrosa and differentiating it from abscess. In our case, it clearly showed a pouch-like, pulsatile structure moving in and out of the left atrium. This can be of immense help in formulating an appropriate surgical or device strategy.>

Introduction

Pseudo-aneurysm of mitral–aortic intervalvular fibrosa (MAIVF) is a rare and potentially fatal complication of infective endocarditis. It usually occurs with native or prosthetic aortic valve endocarditis. Transesophageal three-dimensional (3D) echocardiography is a sensitive tool in identifying the aneurysm. An accurate delineation of the anatomy helps in formulating an appropriate interventional strategy.

Case report

A 30-year-old man presented to our out-patient department with complaints of dyspnea on exertion of New York Heart Association class II, for the past five years. He had undergone aortic and mitral valve replacement in 2004 and was admitted with septic shock due to infective endocarditis of prosthetic aortic valve in 2009. The patient recovered over a period of two months and he presented to our out-patient department with progressive dyspnea for six months in 2014. On examination the pulse rate was 84 per minute and blood pressure 110/70 mmHg. Cardiovascular examination revealed pan systolic murmur at the apex and preserved prosthetic valve clicks. There was no clinical evidence of infective endocarditis.

Chest X-ray showed gross cardiomegaly with cardiothoracic ratio more than 80% (Fig. 1A). Electrocardiogram showed atrial fibrillation with controlled ventricular rate and left ventricular hypertrophy (Fig. 1B). Two-dimensional transthoracic echocardiography (TTE) showed a pseudo-aneurysm in the region of the MAIVF with mitral regurgitation on color flow imaging (Fig. 1C). No aortic regurgitation was noted on color flow imaging. Both prosthetic valves function was normal. There were no prosthetic valvular vegetations. There was severe tricuspid regurgitation with grossly dilated right atrium and right ventricle and pulmonary artery systolic pressures of 70 mmHg. Trans-esophageal echocardiography (TEE) color Doppler showed two color flow into left atrium (LA) through two separate openings (Fig. 1D). TEE using X-plane imaging with and without color Doppler confirmed the pseudo-aneurysm in the region of MAIVF. Subsequent trans-esophageal 3D echocardiography showed a pouch-like lesion in the region of the MAIVF protruding into the LA in systole and collapsing in diastole (Fig. 1E). It also demonstrated a rent in its wall and communication with LA causing a shunt in systole (Fig. 1F).

Fig. 1.

(A) Chest X-ray showing gross cardiomegaly with cardiothoracic ratio more than 80%. (B) Electrocardiogram showing atrial fibrillation with controlled ventricular rate and left ventricular hypertrophy. (C) Transthoracic echocardiogram showing mitral regurgitation on color flow imaging. (D) Transesophageal echocardiogram color Doppler showed two color flow into left atrium through two separate openings. (E) Transesophageal three-dimensional echocardiography showing a pouch-like lesion (arrow) in the region of the mitral–aortic intervalvular fibrosa (MAIVF) protruding into the left atrium in systole and collapsing in diastole. (F) It also demonstrated left ventricular side opening (arrow) of MAIVF.

Discussion

The MAIVF is a small area which forms the junction between the left half of the noncoronary cusp and the adjacent third of the left coronary cusp of the aortic valve and the anterior mitral leaflet [1]. It is a thin, fibrous, and relatively avascular tissue, with predisposition to infection and abscess formation [2]. The abscesses may subsequently rupture into the ventricle outflow tract and LA or organize into a pseudo-aneurysm [3]. The pseudo-aneurysm can enlarge and compress left coronary artery causing angina [4] or rupture to create a communication between left ventricular outflow tract and LA. When this occurs, the clinical picture resembles that of heart failure [3], as in our patient.

Echocardiogram remains the mainstay in the diagnosis of infective endocarditis and its complications. Two dimensional TTE may be a better tool for qualitative assessment of the space of MAIVF but TEE is superior to TTE in the detection of pseudo-aneurysm of MAIVF. The sensitivity of TEE is about 90% [5]. In this regard, a real-time 3D echocardiography provides useful information in understanding the anatomy [6], [7]. However, it is hard to differentiate a smaller pseudo-aneurysm from an abscess. However, in our case, it clearly showed a pouch-like, pulsatile structure moving in and out of the LA which can easily differentiate MAIVF from abscess. This can be of immense help in formulating an appropriate surgical or device strategy.

Our patient refused surgical/percutaneous device therapy and wished to be on medical management.

Pseudo-aneurysm of MAIVF is a rare complication of prosthetic valve endocarditis. TEE is sensitive for diagnosis. Surgery remains the treatment of choice. 3D echocardiogram provides a better insight into the anatomy and helps in formulating an appropriate surgical or device strategy in the treatment.

Conflict of interest

The authors have no conflict of interest.