Can retrograde perfusion mitigate cerebral injury after particulate embolization? A study in a chronic porcine model.
OBJECTIVE
We assessed the impact on histologic and behavioral outcome of an interval of retrograde cerebral perfusion after arterial embolization, comparing retrograde cerebral perfusion with and without inferior vena caval occlusion with continued antegrade perfusion.


METHODS
Sixty Yorkshire pigs (27 to 30 kg) were randomly assigned to the following groups: antegrade cerebral perfusion control; antegrade cerebral perfusion after embolization; retrograde cerebral perfusion control; retrograde cerebral perfusion after embolization; retrograde cerebral perfusion with inferior vena cava occlusion, retrograde cerebral perfusion with inferior vena cava occlusion control, and retrograde cerebral perfusion with inferior vena cava occlusion after embolization. After cooling to 20 degrees C, a bolus of 200 mg of polystyrene microspheres 250 to 750 (microm diameter (or saline solution) was injected into the isolated aortic arch. After 5 minutes of antegrade cerebral perfusion, 25 minutes of antegrade cerebral perfusion, retrograde cerebral perfusion, or retrograde cerebral perfusion with inferior vena cava occlusion was instituted. After the operation, all animals underwent daily assessment of neurologic status until the time of death on day 7.


RESULTS
Aortic arch return, cerebral vascular resistance, and oxygen extraction data during retrograde cerebral perfusion showed differences, suggesting that more effective flow occurs during retrograde cerebral perfusion with inferior vena cava occlusion, which also resulted in more pronounced fluid sequestration. Microsphere recovery from the brain revealed significantly fewer emboli after retrograde cerebral perfusion with inferior vena cava occlusion. Behavioral scores showed full recovery in all but one control animal (after retrograde cerebral perfusion with inferior vena cava occlusion) by day 7 but were considerably lower after embolization, with no significant differences between groups. The extent of histopathologic injury was not significantly different among embolized groups. Although no histopathologic lesions were present in either the antegrade cerebral perfusion control group or the retrograde cerebral perfusion control group, mild significant ischemic damage occurred after retrograde cerebral perfusion with inferior vena cava occlusion even in control animals.


CONCLUSIONS
Although effective washout of particulate emboli from the brain can be achieved with retrograde cerebral perfusion with inferior vena cava occlusion, no advantage of retrograde cerebral perfusion with inferior vena cava occlusion after embolization is seen from behavioral scores, electroencephalographic recovery, or histopathologic examination; retrograde cerebral perfusion with inferior vena cava occlusion results in greater fluid sequestration and mild histopathologic injury even in control animals. Retrograde cerebral perfusion with inferior vena cava occlusion shows clear promise in the management of embolization, but further refinements must be sought to address its still worrisome potential for harm.
Juvonen
T
T
Department of Cardiothoracic Surgery, The Mount Sinai Medical Center, New York, NY 10029, USA.
Weisz
D J
DJ
Wolfe
D
D
Zhang
N
N
Bodian
C A
CA
McCullough
J N
JN
Mezrow
C K
CK
Griepp
R B
RB
D000818:Animals; D001784:Blood Gas Analysis; D001921:Brain / Q000098:blood supply* / Q000473:pathology; D002315:Cardiopulmonary Bypass; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials; D005500:Follow-Up Studies; D002542:Intracranial Embolism and Thrombosis / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D019344:Lactic Acid / Q000378:metabolism; D008863:Microspheres; D010101:Oxygen Consumption; D010477:Perfusion / Q000379:methods; D011897:Random Allocation; D012039:Regional Blood Flow; D013552:Swine; D016896:Treatment Outcome; D014655:Vascular Resistance
D019344:Lactic Acid