Effect on the brain of two techniques of myocardial protection.

This study compared the occurrence of intraoperative microemboli and postoperative changes in neuropsychological performance in 195 patients undergoing coronary artery bypass grafting who were randomized to intermittent crossclamp fibrillation or cardioplegic arrest. Cerebral microemboli were recorded from cannulation to 15 min after decannulation, using transcranial Doppler in 166 patients. Microemboli in relation to 9 surgical events were also noted. Neuropsychological change scores were obtained by comparing cognitive performance preoperatively with that at 6-8 weeks after surgery. The median number of microemboli detected was 105 (range, 9-1,757) in the fibrillation group, and 110 (range, 1-1,306) in the cardioplegia group, with no significant difference between groups. There was also no significant difference between groups in the generation of microemboli during any of the surgical events. Neuropsychological tests were completed postoperatively by 177 participants, with no significant differences in performance found between the 2 groups. Given the equivalence of the effect of intermittent crossclamp fibrillation and cardioplegic arrest on microemboli and neuropsychology, consideration of which form of myocardial protection to employ should perhaps focus more on which method affords most protection to the heart.

An intraoperative assessment of the ascending aorta: a comparison of digital palpation, transesophageal echocardiography, and epiaortic ultrasonography.

OBJECTIVES: There are a number of techniques available to assess the aorta for atheromatous disease in the intraoperative period. This study compared the relationship among the findings of digital palpation (DP), transesophageal echocardiography (TEE), and epiaortic ultrasound (EAU) in the detection of atheroma in the ascending aorta. DESIGN: A prospective, observational study. SETTING: A single-institution, cardiothoracic specialty hospital. PARTICIPANTS: One hundred fifty-four patients undergoing elective cardiac surgery. INTERVENTIONS: The ascending aorta of patients undergoing elective coronary artery bypass surgery was assessed for atheroma by means of the 3 techniques. Atheroma was scored as present or absent. The sensitivity and specificity of the techniques were compared. MEASUREMENTS AND MAIN RESULTS: Assuming EAU provides the "gold standard," the sensitivity of both TEE and DP were low. Digital palpation identified only 20 patients (12%); TEE 31 patients (20%); and, in contrast, EAU detected atheroma in 81 patients (53%). There were 3 and 6 false-positives by DP and TEE, respectively. CONCLUSION: Assuming EAU as the "gold standard" to detect atheroma, this study has shown that when assessing the ascending aorta neither DP nor TEE appear sensitive. This study supports the proposal that detection of atheroma should be performed by EAU.