Rare Finegoldia magna-Endocarditis leads to an early Giant Pseudoaneurysm of the ascending Aorta compressing the left main stem

Introduction: Endocarditis of prosthetic valves caused by Finegoldia magna is a rare disease. There are only seven cases published in the literature defining this infection as a subacute, early endocarditis (60 days) following valve replacement (85%), with an elevated mortality (28%). The anaerobic gram positive coccus is part of the normal flora of human mucocutaneous surfaces but can also be involved in a wide variety of clinically significant infections. We present a 58year old patient with an incidential finding of a giant pseudoaneurysm compressing the left main stem 5 months after initial operation due to Finegoldia magna-Endocarditis.

Case presentation: The follow-up echocardiography present a perfused pseudoaneurysm, 70 mm at its greatest extent. Angiography showed a complete compression of the left main stem and the ascending aorta during systole. The computed tomography confirmed these findings (Fig. 1).

Surgical treatment and outcome: Prior to medial re-sternotomy a cannulation of the right subclavian artery and right femoral vein was performed. The pulsating mass compressing the left main stem could be exposed and opened (Fig. 2). Approximately over 70% of the valves' annulus was disconnected from its original placement. A 29 mm stentless biologic prosthesis was sutured into place.

The postoperative course was uneventful. Via microbiological analyses Finegoldia magna could be isolated from the infected valve. Pre- and postoperative bloodcultures showed no microbial growth. An antimicrobial therapy with Penicillin was established.

Conclusion: Endocarditis with Finegoldia magna is a rare complication after valve implantation. Little is known about the aggressiveness and overall clinical significance of the pathogen, especially in the setting of cardiac procedures. Considering our findings and the notedly scarce literature, an infection with Finegoldia magna may lead to a rapid progression about a short time period with life-threatening complications.

SC58Fig. 1: Finegoldia magna