Pulsatile cardiopulmonary bypass failed to prevent neuropsychological dysfunction

To prevent neurological complications during cardiopulmonary bypass, cerebrovascular screenings by magnetic resonance angiography and computed tomographic scan of the brain were performed preoperatively in patients who had ischemic heart disease and all patients aged 60 years or older. From 1996 to 1999, 173 adult patients (mean age 65.1+/-7.7 y) were evaluated. Forty-one patients were considered to be at high risk from the screening tests and pulsatile cardiopulmonary bypass was applied. The remaining 132 patients were placed in the control group. Postoperative cerebral infarction caused by embolism was encountered in three patients (3/173, 1.7%), two in the high-risk group (2/41, 4.8%) and one in the control group (1/132, 0.8%), but the difference between these incidences was not statistically significant. Cerebral infarctions caused by brain hypoperfusion did not occur in this series. A neuropsychological test (Hasegawa's dementia scale, HDS) was done pre- and postoperatively. No one was diagnosed with dementia preoperatively, whereas 7 patients were diagnosed with dementia postoperatively. Among these 7 patients, 6 patients were in the high-risk group (17.1%, 6/35) and one patient was in the control group (0.9%, 1/113). Under these circumstances, using cerebrovascular screening and pulsatile cardiopulmonary bypass, cerebral infarction due to hypoperfusion did not occur, but cerebral infarction due to embolism was encountered, and neuropsychological dysfunction was not prevented.