J Thorac Cardiovasc Surg 2003;125:441
© 2003 The American Association for Thoracic Surgery
Cerebral protection with retrograde cerebral perfusion
Amir Elami, MD
Department of Cardiothoracic Surgery, Hadassah University Hospital, PO Box 12000, Jerusalem 91120, Israel
To the Editor:
In their article Bonser and colleagues
1 claim that the cerebral flow resulting from retrograde cerebral perfusion (RCP) is insufficient to make a major contribution to cerebral oxygenation and that the brain remains ischemic. In the discussion of their impressive work, the authors stated correctly that current data suggest that RCP might provide only little brain perfusion in human subjects compared with antegrade baseline cerebral flow. Should we abandon this adjunct to hypothermic circulatory arrest, or should we explore methods to maximize the benefits from its application? The effort to improve the effectiveness of RCP during hypothermic circulatory arrest should combine reduction of the metabolic activity with simultaneous increase of blood flow to fulfill the residual metabolic requirements of the brain. In a small series my colleagues and I 2 demonstrated that the introduction of vasodilators and anesthetics into the retrograde perfusate tripled RCP flow without increase in pressure and with concomitant suppression of electric activity. In the present study it is not stated whether brain electric activity was monitored, and the individual RCP flow is not specified. Simple pharmacologic manipulations might augment RCP to 20% or 30% of cerebral flow instead of only 10%. The administration of potent anesthetics or other neuroprotective agents might mitigate the metabolic needs of the brain. Such maneuvers will render the brain less ischemic, allowing safer circulatory arrest.
References
- Bonser RS, Wong CH, Harrington D, Pagano D, Wilkes M, Clutton-Brock T, et al. Failure of retrograde cerebral perfusion to attenuate metabolic changes associated with hypothermic circulatory arrest. J Thorac Cardiovasc Surg. 2002;123:943-50.[Abstract/Free Full Text]
- Shenkman Z, Elami A, Weiss YG, Glantz L, Milgalter E, Drenger B, et al. Cerebral protection using retrograde cerebral perfusion during profound hypothermic circulatory arrest. Can J Anaesth. 1997;44:1096-101.[Medline]
