Cerebral complications of cardiac surgery

Abstract

Cardiovascular disease is among the most prevalent human diseases, and the leading cause of death and disability in the world. Many patients with heart disease eventually undergo cardiac surgery to relieve symptoms, to reverse damage or to prevent further disease progression. Cardiac surgery generally has a low risk of mortality and can often restore patients’ quality of life. Despite these reassuring facts and the major advances in the field of cardiac surgery, clinicians recognize that patients are still concerned about their cerebral outcome after cardiac surgery. For cardiac surgical patients, some of these concerns are justified. Cardiac surgery can be complicated by a broad range of cerebral complications, such as strokes, hallucinations, delirium and postoperative cognitive dysfunction (POCD). In general, cerebral complications are common and unduly increase healthcare expenses. Research efforts to advance knowledge about the etiology of postoperative cognitive dysfunction and other more subtle cerebral complications of heart surgery have been hindered by methodological difficulties. This is not just because the potential etiologic factors are complex and variable but also because postoperative cognitive dysfunction is an outcome that is particularly difficult to measure. The diagnosis requires a set of neuropsychological tests that has to be administered repeatedly that is labor intensive and costly. The selection of neuropsychological tests and the method of statistical processing of the test results have great impact on the results. These problems are reflected by the enormous variety of reported incidences of cognitive dysfunction in the literature and although many studies have been carried out, their results are very hard to compare and base uniform conclusions upon.