Objective: Subdural hemorrhage (SDH) has been reported to be the most frequent intracranial hemorrhagic complication following open heart surgery; however, its clinical features and pathophysiology remain unclear. The aim of this retrospective study was to elucidate the incidence, clinical course, and factors associated with the development of symptomatic SDH following heart valve surgery.
Methods: A retrospective review of medical records on the development of symptomatic SDH after heart valve surgery involving cardiopulmonary bypass (CPB) from April 2011 to March 2016 was performed. Patients who had undergone preoperative cranial computed tomography (CT) or brain magnetic resonance imaging (MRI) were included in this study, and factors associated with SDH following heart valve surgery were analyzed. When neurological symptoms developed after heart valve surgery, cranial CT or brain MRI was performed.
Results: A total of 556 patients who had undergone heart valve surgery were analyzed. Among these patients, symptomatic SDH occurred in 11 (2.0%). The mean duration of symptomatic onset was 10.1 days (range 2-37 days). Ten of 11 patients (90.9%) developed SDH in the posterior fossa or occipital convexity. Logistic regression analysis revealed longer aortic clamp time (95% CI 1.00-1.10, p = 0.04), higher dose of heparin after surgery (95% CI 1.00-1.02, p = 0.001), and higher pulmonary artery pressure (PAP) just before disconnection of the CPB (95% CI 1.01-1.37, p = 0.04) as significantly associated with the development of SDH.
Conclusions: The incidence of symptomatic SDH following heart valve surgery was 2.0%. Symptoms due to SDH usually developed a few days to 1 month after surgery. Surprisingly, most SDHs developed in the posterior fossa or occipital convexity following heart valve surgery. A longer aortic clamp time, higher dose of heparin after surgery, and higher PAP just before disconnection of the CPB were related to the development of symptomatic SDH following heart valve surgery.
Keywords: cardiopulmonary bypass; heart valve surgery; posterior fossa; subdural hemorrhage; vascular disorders, endovascular neurosurgery.