**5. Operations with recent stroke**

the left and right main coronary ostia for anastomosis to the allograft without undue tension. Raanani et al. described surgical reconstruction of the left main coronary artery using an autologous pericardial or saphenous vein patch [58]. The second challenge is achieving adequate resection and debridement of the distal graft-to-aorta anastomosis, which may require deep hypothermia and circulatory arrest. Furthermore, an allograft may not have sufficient length to reach the distal aortic anastomosis. Sabik et al. described the use of a second

High operative mortality rates have been reported for the replacement of infected valve-conduits, attributed to the degree of surgical difficulty. In a study of 11 patients with infected ascending aortic grafts who underwent composite valve graft placement by LeMaire and Coselli in 2007, a 30-day mortality rate of 46% was reported [59]. In comparison, a study of 12 patients who underwent composite replacement of the aortic valve and ascending aorta for infective endocarditis by Ralph-Edwards et al. reported an operative survival rate of 91.7% [60]. In this series, extensive debridement was performed, often requiring resection of the infected portion of the left ventricular outflow tract with circumferential reconstruction using bovine pericardium. It was often necessary to extend the length of the coronary arteries with saphenous vein or expanded polytetrafluoroethylene grafts to facilitate reimplantation as well [60]. As described, in a study of 23 patients who underwent ascending aorta and aortic valve replacement with the prosthetic material for acute PVE, Hagl et al. reported an 11% in-hospital mortality rate and a

Endocarditis is rare after mitral valve repair. The rate of freedom from endocarditis at 10 years following mitral valve repair is estimated at 95–99% [61]. Although native valve endocarditis can often be managed medically, PVE typically requires early operation. In a study of 22 patients with endocarditis after mitral valve repair by Gillinov et al., 68.1% underwent repeat mitral valve operations. Mitral valve replacement was required in 73.3%, and rerepair was performed in 26.7%. Following reoperation, 30-day, 1-year, and 5-year rates of freedom from reoperation were 65, 41, and 26%, respectively [61]. The principles of surgical management include the removal of all infected and devitalized tissue as well as the removal of the annuloplasty ring. If rerepair is not possible, replacement is necessary. Destruction of the mitral annular region is less common than periaortic annular destruction. Surgical debridement and resection of abscess formation in the posterior mitral annulus or in the region of aortomitral continuity is a significant surgical challenge, associated with a high operative mortality.

The mitral annulus may be reconstructed with autologous pericardium after debridement, as described by David and Feindel [62]. If the posterior mitral annular region requires reconstruction, this may be done with pericardium as well [15]. If necessary, the new mitral prosthesis may be translocated onto either the atrial or ventricular side of the annulus. If technically feasible, ventricular translocation may prevent exposure of the attenuated area to high pressure [15]. Aortomitral discontinuity is uncommon and particularly difficult to reconstruct. This trigonal region may be reconstructed using a modification of the technique

allograft to bridge the distance between the first allograft and the aorta [44].

4% incidence of recurrent endocarditis requiring reoperation at 4 months [55].

**4.2. Mitral prosthetic valve endocarditis**

122 Advanced Concepts in Endocarditis

described by Rastan et al. [63].

Neurologic sequelae occur in 25–70% of cases of infective endocarditis and portend increased mortality [64]. The mechanisms of neurologic injury include ischemic infarction secondary to embolization, hemorrhagic transformation of ischemic infarction, pyogenic arteritis, and rupture of intracranial mycotic aneurysm [65]. Systemic embolization occurs in 12.9% of patients with left-sided endocarditis after initiation of antibiotic therapy [66]. Of those with embolic events, 52% affect the central nervous system, and 65% occur within 2 weeks of initiation of antibiotic therapy [66]. Risk factors for embolization include vegetation size and mobility [66, 67]. There is no significant difference in incidence of embolization between native and prosthetic valve endocarditis. The risk of embolization is higher in mitral endocarditis than in aortic endocarditis [66].

The most common neurologic complication is ischemic stroke [65]. From a surgical perspective, the primary concern is hemorrhagic transformation of an ischemic infarct as a consequence of anticoagulation required during cardiopulmonary bypass [65]. Asymptomatic cerebral infarctions may occur in 30–40% of patients with endocarditis [64]. For this reason, it may be advisable to exclude an ischemic stroke with preoperative computed tomography. Clinically, silent or small infarcts should not delay cardiac surgery, since the risk of progression is low [64]. However, with the evidence of larger infarcts or intracerebral hemorrhage, surgical intervention should be delayed up to 4 weeks due to the associated risk of a significant neurologic event during cardiopulmonary bypass [64]. In such patients, the need for valve replacement should be balanced with high perioperative neurologic risk.
