DIRECTLY VISUALIZED CEREBRAL-CIRCULATION DURING RETROGRADE CEREBRAL PERFUSION

Background. Retrograde cerebral perfusion (RCP) was clinically introdu ced as a supportive technique to protect the brain during operations o n the thoracic aorta. However, it remains unclear whether this procedu re provides adequate blood supply for the brain. Methods. We have obse rved the optic fundus of patients undergoing operation on the thoracic aorta to evaluate the cerebral circulation during RCP, There were 1 m ale and 3 female patients, ages ranged from 34 to 78 years, RCP time r anged from 39 to 70 minutes, and blood flow via the superior vena cava cannula ranged from 200 to 400 ml/min. Results. The arteries of the r etina showed marked constrictions soon after the initiation of RCP, Th e veins showed almost normal diameter, The large arteries were reduced to thin threads, while the smaller arteries were invisible at 30 minu tes after the initiation of retrograde cerebral perfusion. Conclusion. Ophthalmoscopic findings demonstrate the reduction of cerebral blood flow, especially in arteries, during RCP, Although RCP is a useful tec hnique for cerebral protection, it could be mentioned that the blood s upply to the brain by RCP is not enough to maintain good cerebral meta bolism.