P639 Dehiscence of Bio-Bentall aortic graft after repeated staphylococcus aureus infective endocarditis
Authors: Ovsenik A , Klokocovnik T , Cercek M , Frljak S , Bervar M 
Published: January 2020

Abstract

Introduction
Echocardiography is the primary imaging modality in prosthetic valve endocarditis (PVE). It is characterised by a lower incidence of vegetations and a higher incidence of perivalvular complications, including valve dehiscence and must be suspected in case of a new periprosthetic regurgitation, even without vegetation or abscess. Multimodality approach is mandatory to detect penetration of the process into the valve ring, aortic root or ascending aorta for complete operative preparation.

Case presentation
A 22-year old male, with history of Bio-Bentall procedure due to Staphylococcus aureus (S.aureus) infective endocarditis on the mechanical aortic valve (AV) two years priorly, presented to the emergency department with sudden dyspnea without fever. He was treated for pneumonia due to increased inflammatory parameters and bilateral pulmonary infiltrates on X-Ray. Due to complete regression of infiltrates over the night, transthoracic echocardiography (TTE) was performed, revealing almost complete dehiscence of the AV graft with most of the antegrade and retrograde flow through the pseudoaneurismatic sac, communicating with the ascending aorta at the distal graft dehiscence, no clear vegetation was seen. With clearly visible valve and supravalvular pathology of the AV on TTE, we proceeded to computed tomography angiography (CTA) of the thoracic aorta, which showed dissection and delineated rupture of Bio-Bentall graft. The pseudoaneurismatic sac surrounding bulbar portion of Bentall graft, communicating with the left outflow tract and sinus Valsave was seen, compressing ostial portion of the left main and right coronary artery. Re-Bio-Bentall procedure and venous grafting of the left anterior descendant and right coronary artery were performed. Intraoperative transthoracic transesophageal echocardiography (TEE) confirmed the findings, already provided by TTE and CTA. Hemocultures as well as sonication of the removed graft remained negative for bacteria. Postoperatively, left ventricular failure developed, requiring VA ECMO. On postoperative CTA, changes were consistent with usual postprocedural changes. After prolonged rehabilitation, the patient was released home, clinically stable, but with severely reduced ejection fraction of the left ventricle, severe diastolic dysfunction and mild mitral regurgitation.

Conclusion
TTE is a very useful, non-invasive imaging method in diagnosing PVE and its complications, which can be upgraded with TEE or CTA to provide additional information on the ascending aorta. In a patient, with the past history of repetitive S. aureus infective endocarditis, presenting with Bio-Bental dehiscence, PVE cannot be excluded completely. Even though the timing for follow-up imaging is not well defined in current guidelines, patients with dehiscence of prosthetic valve or graft present a high risk group, demanding individual follow-up planning and lower threshold for imaging referral.
Abstract P639 Figure. Dehiscence of aortic valve graft