On-pump beating heart versus hypothermic arrested heart valve replacement surgery.

BACKGROUND: Comparison of neurological parameters in patients undergoing prosthetic heart valve replacement with two operating techniques-either cardioplegic arrest of the heart under hypothermic cardiopulmonary bypass (CPB) or the heart beating on normothermic bypass, with or without cross-clamping the aorta, without cardioplegic arrest. methods: Fifty valvular surgery patients were randomly assigned into three groups. Sixteen patients underwent beating heart valve replacement with normothermic bypass without cross-clamping the aorta, 17 patients underwent the same procedure with cross-clamping the aorta and retrograde coronary sinus perfusion, and the remaining 17 patients had conventional surgery with hypothermic bypass and cardioplegic arrest. RESULTS: Two-channel electroencephalography (EEG) was recorded to assess changes in cerebral cortical synaptic activity and 95% spectral edge frequency values were recorded continuously. Bispectral monitoring was used to measure the depth of anesthesia. Blood flow rates in middle cerebral artery (MCA) were measured by transcranial Doppler (TCD). Reduction in spectral edge frequency (>50%) or bispectral index (BIS) (<20) or transcranial Doppler flow velocity (>50%) was detected in four patients in Group 1, five patients in Group 2, and three patients in Group 3. BIS or EEG values never reached zero, which indicates isoelectric silence during surgery. Gross neurological examinations were normal in all patients postoperatively. CONCLUSION: There is no difference regarding neurological monitoring results between on-pump beating heart and hypothermic arrested heart valve replacement surgery. Also no significant difference was encountered among the groups regarding the clinical outcomes.

Assessment of cerebral blood flow with transcranial Doppler in right brachial artery perfusion patients.

BACKGROUND: Antegrade selective cerebral perfusion as a method of cerebral protection during the correction of aortic arch aneurysms and dissections is considered as a safe method for cerebral protection. There are still some questions remaining to be answered; such as whether cerebral perfusion through contralateral hemisphere is adequate. METHOD: Fifteen consecutive patients (mean age of 53 +/- 3.3 years) underwent surgical reconstruction of aortic arch with antegrade selective cerebral perfusion through the right brachial artery. We monitored maximum, minimum and mean blood flow velocities of bilateral middle cerebral arteries using the transcranial Doppler technique at four different time periods: after induction of anesthesia, during cardiopulmonary bypass, during antegrade selective cerebral perfusion, and after termination of cardiopulmonary bypass. We compared the results of brachial cannulation group with aortic group. RESULTS: Following induction, no significant differences were observed in the right and left middle cerebral artery blood flow velocity measurements in and between the groups. During cardiopulmonary bypass, V(max) and V(mean) decreased significantly in both groups. When two groups were compared there was a significant decrease in the left V(max) values of brachial group (p = 0.048). In-group comparisons revealed that V(max) values were lower in left middle cerebral artery than right middle cerebral artery in brachial group (p = 0.002). With the initiation of antegrade selective cerebral perfusion in brachial group, significant decrease occurred in V(max) and V(mean) when compared with cardiopulmonary bypass values. When left and right sides were compared, although V(min) values remained similar, V(max) and V(mean) values decreased significantly in the left side (p = 0.001 and p = 0.003, respectively). After cardiopulmonary bypass, in both groups, all values restored to initial values and indicated no difference between left and right middle cerebral artery in the groups as well as between the groups. No neurologic deficit was observed in any patient postoperatively. CONCLUSIONS: Antegrade selective cerebral perfusion through the right brachial artery, as a method of cerebral protection for aortic arch repair, seems to provide adequate perfusion for both right and left cerebral hemispheres.

A double-orifice atrioventricular valve case: intraoperative transesophageal echocardiography in diagnosis and treatment.

We describe a 45-yr-old woman with an intermediate type atrioventricular septal defect associated with a double-orifice left atrioventricular valve (DOLAV). We diagnosed this exceptional anomaly by intraoperative transesophageal echocardiography (TEE) during surgery that was scheduled for only a primum type atrial septal defect (ASD) repair. Preoperative transthoracic echocardiography and angiography revealed the ASD but could not demonstrate the DOLAV. We were able to repair this rare and challenging abnormality successfully under the guidance of TEE imaging during the operation. TEE provides valuable information about both anatomy and functional aspect of the valvular structures. Besides its proven role in cardiac surgery, intraoperative use of TEE also serves as a useful tool for diagnosis of such unexpected and potentially missed abnormalities.