Discussion
Endocarditis after composite valve graft root replacement (Bentall
procedure) is not uncommon (16)(17) and is often associated with
periannular abscess, disruption of aortic-ventricular junction and
aortic false aneurysm (18-20). Redo root surgery is warranted in these
cases and may poses difficulties in chest re-entry, in providing an
adequate myocardial protection and handling of frail and infected tissue
(21,22). These patients can further present severe medical issues with
ongoing heart failure and a poor controlled septic status, which account
for a high perioperative mortality rate (9). Despite these technical and
medical challenges, previous experiences reported good outcomes after
reoperation for Bentall infection (9,10,11,21,22) and our results, early
mortality of 10% and acceptable survival at 7-year follow-up, are in
keeping with these findings.
Two large multi-institutional registries have recently shown that
failure to undertake an operation in patients with infective
endocarditis and presenting an indication for surgical treatment is a
risk factor for early mortality (4,23). On the contrary, a conservative
approach seemed providing an acceptable survival especially in patients
who did not have local complications, such as abscess, fistula or false
aneurysm. These findings were retrieved from mixed populations,
including native and prosthetic valve endocarditis, and few evidences
exist regarding patients who had a previous root replacement with a
valve graft conduit.
We found that a conservative treatment can be associated with a dismal
early and mid-term survival also in patients who did not present at the
admission with local infective complications and severe tissue
disruption. In our series, the most common reason for a conservative
treatment was the presence of stable haemodynamic, controlled sepsis and
the absence of local infective complications. Among these six patients
who had no urgent indication for a surgical procedure (14,24), four did
generally well and had a satisfactory survival, while two patients
sustained a relapse of infective endocarditis with uncontrolled sepsis
and heart failure.
Machelar et al. reported their experience in 8 patients with aortic
valve graft conduit infection who were ultimately treated conservatively
(25). Among them, one died due to cerebral haemorrhage after 6 weeks and
one due to polymicrobial infection after 18 months. Another patient
sustained a recurrent infection, and one was still on treatment. Four
patients had complete remission during a follow-up time ranging from 30
to 68 months and, noteworthy, none of them had local infective
complications at the admission. Similar results were found in our
population, as we showed that patients with a stable clinical picture in
absence of periannular abscess or aorto-ventricular disruption could be
successfully managed with medical treatment in the acute setting.
Alongside a less severe anatomical disruption, Staphylococcus aureus was
not isolated, both in Machelar’s and our experiences, in any of the
patients who sustained a complete remission after lone antibiotic
treatment.