Emergency Surgery for Infective Prosthetic Endocarditis of the Aortic Root in Patients with Functioning Coronary Artery Bypass Grafts

Relevance Bacterial infection of a prosthetic valve is a serious and common clinical problem in cardiac surgery. Cases of infection of biological prostheses after previous combined cardiac surgeries present a particular challenge. Numerous studies demonstrate the effectiveness of aortic allografts for the surgical treatment of this complication, making them a viable option. In the clinical cases presented below, we not only confirm this point of view but also examine in detail the technical aspects of performing such surgeries.

Aim To evaluate the effectiveness of emergency surgical treatment for severe prosthetic endocarditis of aortic bioprosthesis using aortic allografts in patients with functioning mammary and coronary artery bypass grafts after previous bioprosthetic aortic valve replacement and coronary artery bypass grafting, based on an analysis of clinical cases.

Objectives 1. To describe the clinical features and diagnostic criteria of severe prosthetic endocarditis in patients with functioning coronary artery bypass grafts. 2 To present a technique for emergency surgical intervention using aortic allograft in this patient population, and to analyze the results of this

Material and methods The study included two patients with proven aortic valve prosthesis infection following bioprosthetic aortic root replacement and coronary artery bypass grafting. Our technique involves meticulous exposure of the coronary bypass grafts and the functioning left internal mammary artery, complete removal of infected prosthetic material, antegrade crystalloid cardioplegia via the coronary artery ostia and autologous vein grafts, and total aortic root replacement using aortic allograft.

Results The time from the primary surgery to the reoperation and the time from hospital admission to the current surgery were 3 months and 19 months, 8 hours, and 16 hours, respectively. Both patients underwent total aortic root replacement with allograft. The identified pathogens were Pediococcus pentosaceus and Streptococcus viridans. The patients were at high surgical risk (EuroScore II 64.97 and 58.28%); however, the postoperative period was uneventful in both cases. The patients were discharged with normal blood counts and perfect allograft function. The follow-up periods were 12 and 19 months. Currently, the patients have not experienced recurrent infection or structural degeneration of the allograft.

Conclusions Patients with prosthetic endocarditis after combined procedures represent a particularly high-risk surgical group. Reoperations in those patients are urgent and technically challenging. To protect the myocardium, partial cardiolysis can be performed to occlude the proximal portion of the internal mammary artery, while preserving the bypass graft function and allowing for its temporary clamping. Antegrade infusion of crystalloid solution into coronary ostia and venous grafts during cardioplegia is the preferred method. Total aortic root replacement using an aortic allograft with reimplantation of bypass grafts into the allograft has demonstrated excellent initial and mid-term results, and should be considered the procedure of choice.

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