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Department of Anesthesiology Division of Thoracic and Cardiovascular Surgery,, Department of Surgery, Shands Hospital at the University of Florida, Gainesville, FL
To the Editor:
We read with interest the case report by Drs. Schwarte and Hartmann (1). The authors are to be congratulated for their rapid and innovative solution to such a perilous clinical situation, and one can hardly find fault with such a successful outcome. There are, however, other potential solutions worthy of mention that may have been similarly employed in this clinical scenario.
Kouchoukos et al. are perhaps the major published supporters of performing this and perhaps all Crawford-type thoracoabdominal aneurysm repairs under conditions of deep hypothermic circulatory arrest (2). Indeed, we not infrequently employ circulatory arrest at our institution for single-staged repairs of distal arch and thoracic or thoracoabdominal aneurysms through a left thoracotomy approach, or single-staged repair of combined ascending/arch/proximal descending aortic aneurysms through a sternotomy approach (3). While the arrest period is typically much longer than 3 min, it is performed after cooling to 18°C for cerebral and spinal cord protection. Massive hemorrhage in this scenario is unlikely, as the repair is conducted primarily in a bloodless field, and any anastomotic leaks may be addressed early in the warming period under controlled circumstances.
If the approach is as described and such a scenario of massive hemorrhage develops, other alternatives are still available. We have instituted full cardiopulmonary bypass in similar situations at our institution via femoral arterial and venous cannulation if indeed the hemorrhage can be stayed temporarily by the surgeon’s finger. Exposure is typically sufficient to insert a left atrial vent to prevent ventricular distention during fibrillation. After cooling to deep hypothermia (and warming the surgeon’s finger), the repair can again be performed under circulatory arrest with the added comfort of cerebral protection, as in many instances, such a repair may be impossible in 3 min.
Similarly, if cardiopulmonary bypass is impossible, bilateral warm cerebral ischemia can be avoided by moving the aortic cross-clamp proximal to the left carotid artery. This maneuver allows for a bloodless surgical field while maintaining right hemispheric perfusion via the innominate artery, and potentially maintaining left hemispheric perfusion through the circle of Willis via either (or both) the vertebral circulation or the anterior communicating artery. Alternatively, brief periods of circulatory arrest can be rapidly, reliably, and typically reversibly achieved by inducing ventricular fibrillation. This is accomplished by applying an alternating current (AC) impulse through a device in direct contact with the cardiac surface, as is routinely done in many cardiac surgical centers to facilitate open cardiac chamber procedures without application of an aortic cross-clamp.
We would also advocate the use of a pulse dose of a barbiturate, such as sodium thiopental, in order to decrease the cerebral and spinal cord oxygen consumption prior to inducing warm circulatory arrest, realizing that epinephrine rescue therapy would likely be necessary from this intervention. This practice is common for comparable clinical situations involving short-term induced warm cerebral ischemia such as placement of temporary clips in cerebral aneurysm surgery (4).
Whatever the case may be, Drs. Schwarte and Hartmann are to be congratulated, as their fast thinking and quick hands certainly averted a potentially catastrophic outcome for their patient.
Acknowledgments
Dr. Hartmann does not wish to respond.
References
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