Management of infectious endocarditis with mycotic aneurysm evaluated by brain magnetic resonance imaging

Cerebral complications of infective endocarditis (IE) [particularly, mycotic aneurysm, visualized as a hypointense spot on T2*-weighted brain magnetic resonance imaging (MRI)] are associated with a high incidence of postoperative cerebral or subarachnoid hemorrhage. We have adopted a policy of performing elective open heart surgery after performing a MRI enhanced by gadolinium in such patients whenever possible after improvement in inflammatory findings around a cerebral aneurysm. Fifty-six patients (35 men and 21 women, mean age 56 years) diagnosed with active-phase IE between January 2000 and December 2010 were analysed retrospectively. Six patients who had not undergone MRI were excluded. The remaining patients were classified into four groups according to preoperative brain MRI findings-Group A (n = 13): cerebral haemorrhage, cerebral infarction, abscess and encephalitis; Group B (n = 7): simple or multiple black dots ( = hypointensive spots) with cerebral haemorrhage or cerebral infarction; Group C (n = 15): simple or multiple black dots alone; Group D (n = 15): no abnormal MRI findings. None of the 12 patients who successfully underwent elective surgery in Groups B and C developed postoperative cerebral complications. Brain MRI is an important tool for the detection of asymptomatic intracranial abnormalities associated with IE and evaluation of the preoperative bleeding risk of patients. Patients with contrast enhancement around black dots are at high risk for bleeding, and performing open heart surgery in such patients whenever possible after the improvement of inflammatory findings reduces the potential risk of cerebral haemorrhage.