Homografts for the management of graft infections in the ascending aortic position

Abstract

We read with great interest the article by Khaladj et al. [1] describing their experience with cryopreserved homografts for the management of a severe complication following reconstructive surgery on the ascending aorta and aortic arch, namely prosthetic graft infection. However, we would like to add some comments on the topic. According to their institutional policy, all patients with infected grafts of their ascending aorta, where the aortic arch was also involved, were treated by removal and replacement of the prosthetic material with homografts. Historically, replacement of infected thoracic aortic graft has been reported by individual surgeons, however, with unsatisfactory results. Hospital mortality rates have been as great as 46% [2] typically resulting from the invasiveness and complexity of the procedure, emergency conditions, contaminated field and the difficulties of exposure in the redo aortic setting. Our group, as others [3] too, experienced exceptionally disappointing results following the principle of redo ascending/arch prosthetic graft replacement, due to uncontrollable infective process. We congratulate the outstanding work of Khaladj et al. [1] from Hannover, who reported in their explants series a hospital mortality rate of 24%. This is the largest single-centre experience published so far treating 17 patients with cryopreserved homografts in the ascending/arch and aortic root. However, surgical mortality and morbidity are still a major concern with this aggressive treatment strategy. Moreover, there are no surgical guidelines on proper surgical management for such cases. Other strategies that have been applied in the surgical treatment of ascending/arch prosthetic graft infection are based on the principle of a more conservative, non-resectional, and thus, graftsparing surgical approach [2–6]. It is well documented that many institutions have switched during the last decades to this so-called ‘in situ preservation’ concept performing debridement of perigraft-infected mediastinal tissue, open surgical disinfection and transposition of viable omentum, as suggested by Hargrove and Edmunds [4] and Coselli et al. [5], with excellent clinical results. We were, therefore, surprised to read that ‘the use of omentum has not been evaluated for ascending aortic graft infections’. The literature certainly provides sufficient information concerning the role of this method which is feasible, safe and highly effective in controlling thoracic aortic prosthetic graft infection with superior outcomes when compared with traditional redo ascending/arch prosthetic graft replacement [2–6]. Inspired by a case we treated successfully with open surgical disinfection followed by omentum flap coverage after the Bentall operation and total aortic arch replacement, we reviewed the literature and recognized 77 similar cases for the treatment of infected ascending/arch prosthetic grafts with a collective early survival rate of 95% and a 100% success rate in terms of non-recurrence of graft infection [2–6]. Many of these patients with ascending aortic grafts also received an arch graft, composite valve graft or separate aortic valve prosthesis. We think, as other authors [2–6] too, that the dogma of the need for removal and replacement of the prosthetic graft is unjustified, at least in certain patients with ascending/arch prosthetic graft infection, even after composite aortic root replacement, as long as the infection is not associated with native or prosthetic aortic valve endocarditis or valve dysfunction. The present evidence and knowledge on current preservation strategies has the potential to spare patients high-risk procedures and higher mortality.