Invited Commentary

Abstract

Jassar and colleagues [1Jassar A.S. Bavaria J.E. Szeto W.Y. et al.Graft selection for aortic root replacement in complex active endocarditis: does it matter?.Ann Thorac Surg. 2012; 93: 480-488Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar] have examined the effect of prosthetic valve choice in patients requiring aortic root replacement operations for active endocarditis. The authors retrospectively reviewed 134 patients operated on over a 10-year period, dividing them into those receiving a mechanical valved conduit, a nonhomograft biologic valved conduit, or a homograft. They conclude that choice of valved conduit does not have any demonstrable effects on perioperative or long-term outcomes in this high-risk patient population. The authors are to be commended for trying to answer an important question that frequently arises in clinical practice: what is the best surgical option for patients presenting with destructive aortic root endocarditis? Although the principles of endocarditis surgery are frequently stated in the literature as straightforward pronouncements, including aggressive debridement of all infected material, reconstruction or replacement of debrided vital structures, and targeted antibiotic therapy, the reality is much more complex when surgeons are faced with trying to reconstruct aggressively resected tissue planes. Given the surgical challenges involved in destructive aortic root endocarditis and the lack of clearcut evidence of valve choice superiority, the most prudent advice may be for surgeons to stick with what they know best and to implant the valved conduit with which they have the most experience. Having said this, homografts may be the superior choice for several reasons: One reason is the increased reconstructive options that homografts provide, particularly with regards to reconstruction of the intervalvular body and the anterior leaflet of the mitral valve. Another reason is the superior tissue handling and hemostasis characteristics of homografts. Patients with advanced aortic root endocarditis frequently have several causes for coagulopathy, such as sepsis, reoperation, and long cardiopulmonary bypass times. Suture holes through a homograft are much more hemostatic than those through a porcine root, which can be very important in coagulopathic patients. Lastly and most importantly, the issue of nonsuperiority of homografts has not been adequately proven. Most studies that have argued this point in the literature have been woefully underpowered to make such conclusions. Although Jassar and colleagues [1Jassar A.S. Bavaria J.E. Szeto W.Y. et al.Graft selection for aortic root replacement in complex active endocarditis: does it matter?.Ann Thorac Surg. 2012; 93: 480-488Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar] did not demonstrate beneficial outcomes for patients who received homografts, their small sample size of 36 homografts and incomplete follow-up (80%) make interpretation of their results problematic. In addition, other centers have demonstrated much better freedom from reinfection rates for homograft patients. In the largest series to date, Musci and colleagues [2Musci M. Weng Y. Hübler M. et al.Homograft aortic root replacement in native or prosthetic active infective endocarditis: twenty-year single-center experience.J Thorac Cardiovasc Surg. 2010; 139: 665-673Abstract Full Text Full Text PDF PubMed Scopus (113) Google Scholar] found that among 221 homograft patients, more than 92% were free from reoperation for reinfection 10 years after homograft implantation for endocarditis. For all of the above reasons, I remain a strong proponent of homograft root replacement for patients with advanced infective destruction of the aortic root. The disadvantages of homografts are well known and include increased technical complexity of implantation, costs, availability, and challenging reoperations due to calcification. The latter problem may become less of an issue in the future with increased usage of transcatheter aortic valve implantation. It should also be noted that if a patient with destructive aortic valve endocarditis survives long enough to require a reoperation for structural valve deterioration without recurrent endocarditis, then this should probably be regarded as a major success. Graft Selection for Aortic Root Replacement in Complex Active Endocarditis: Does It Matter?The Annals of Thoracic SurgeryVol. 93Issue 2PreviewEndocarditis affecting the aortic valve, with abscess formation and root destruction, remains a challenge to treat. Aortic root homografts have been advocated because of a perceived lower risk of infective complications than with other root replacement grafts. However, the theoretical advantage of homografts has not been re-evaluated in the modern era. This report is based on an examination of our results for all aortic root replacements in complex, active endocarditis affecting the aortic valve. Full-Text PDF