1. Retrograde cerebral perfusion enhances cerebral protection during prolonged hypothermic circulatory arrest: a study in a chronic porcine model 
Tatu Juvonen, MD, PhD, Ning Zhang, MD, David Wolfe, MD, Donald J Weisz, PhD, Carol A Bodian, DrPH, Howard H Shiang, DVM, Jock N McCullough, MD, Randall B Griepp, MD 
The Annals of Thoracic Surgery 
Volume 66, Issue 1, Pages (July 1998)
DOI: /S (98)

2. Fig 1
Mean ± standard error of the mean rectal and epidural temperatures during the period of experimental intervention. All temperatures remained within 2°C throughout the experiment. Although a slight drift from baseline was apparent in the rectal temperatures, differences between groups occurred only during the last 10 minutes. Epidural temperatures, however, were statistically significantly higher in the ACP group than in any of the other groups beginning at 30 minutes. Both RCP and RCP-O groups had significantly colder temperatures than HCA animals for 10 and 30 minutes, respectively. (ACP = antegrade cerebral perfusion; HCA-HP = circulatory arrest with the head packed in ice; RCP = conventional retrograde perfusion; RCP-O = retrograde perfusion with the inferior vena cava occluded.)
The Annals of Thoracic Surgery  , 38-50DOI: ( /S (98) )

3. Fig 2
Volume of fluid sequestered (the difference between inflow and outflow) during the experimental interval for each of the hypothermic perfusion methods. The median value in each group is significantly different from the median of each of the other groups (p < 0.001). (ACP = antegrade cerebral perfusion; RCP = conventional retrograde perfusion; RCP-O = retrograde perfusion with the inferior vena cava occluded.)
The Annals of Thoracic Surgery  , 38-50DOI: ( /S (98) )

4. Fig 3
Urine output after various interventions during 90 minutes of arrested antegrade circulation at 20°C. Urine output is significantly greater after antegrade cerebral perfusion (ACP) than after retrograde perfusion with the inferior vena cava occluded (RCP-O), but there are no significant differences among the other groups. (HCA-HP = circulatory arrest with the head packed in ice; RCP = conventional retrograde perfusion.)
The Annals of Thoracic Surgery  , 38-50DOI: ( /S (98) )

5. Fig 4
Daily scores indicating behavioral recovery after various hypothermic interventions. A score of 8 or 9 indicates essentially complete recovery; lower scores indicate substantial impairment, and 0 indicates coma or death. All survivors in the ACP and RCP groups recovered completely, whereas some animals had considerable damage after HCA and RCP-O. Behavioral scores on day 5 showed a significant difference between recovery after RCP and HCA (p = 0.01). (ACP = antegrade cerebral perfusion; HCA-HP = circulatory arrest with the head packed in ice; RCP = conventional retrograde perfusion; RCP-O = retrograde perfusion with the inferior vena cava occluded.)
The Annals of Thoracic Surgery  , 38-50DOI: ( /S (98) )

6. Fig 5
Total histopathologic scores after various interventions during arrest of antegrade circulation for 90 minutes at 20°C. The median total score was significantly lower after antegrade perfusion (ACP) than after any other intervention (p < 0.01). A histopathologic score greater than 2, indicating moderate to severe damage, was significantly more common after retrograde perfusion with the inferior vena cava occluded (RCP-O) than after conventional retrograde perfusion (RCP) (p < 0.05). (HCA-HP = circulatory arrest with the head packed in ice.)
The Annals of Thoracic Surgery  , 38-50DOI: ( /S (98) )

7. Fig 6
Total electroencephalographic (EEG) power, as a percentage of baseline recordings at 37°C, in each group during recovery after the various interventions during arrest of antegrade circulation for 90 minutes at 20°C. Recovery of electroencephalographic power was monitored during early rewarming (at 30°C), and at 2 and 4 hours after the start of rewarming. Return of electroencephalographic power was significantly more rapid after antegrade cerebral perfusion (ACP) than after either method of retrograde cerebral perfusion (RCP) or circulatory arrest with the head packed in ice (HCA-HP). Four hours after the start of rewarming, electroencephalographic power more than 10% of baseline had returned in very few animals except in the antegrade cerebral perfusion group, with no significant differences between the remaining groups. (RCP-O = retrograde perfusion with the inferior vena cava occluded.)
The Annals of Thoracic Surgery  , 38-50DOI: ( /S (98) )

8. Fig 7
Mean ± standard error of the mean total power of cervical response to somatosensory evoked potentials (as a percentage of baseline values) during recovery after various interventions during arrest of antegrade circulation at 20°C for 90 minutes. Pairwise comparisons showed significantly better recovery in the antegrade cerebral perfusion (ACP) group than in any of the others during rewarming (p = 0.005) and at 2 hours (p = 0.007), but these differences were no longer present at 4 hours. There were no significant differences among the other groups at any time. (HCA-HP = circulatory arrest with the head packed in ice; RCP = conventional retrograde perfusion; RCP-O = retrograde perfusion with the inferior vena cava occluded.)
The Annals of Thoracic Surgery  , 38-50DOI: ( /S (98) )

9. Fig 8
Median percent recovery of brainstem auditory evoked potentials (BSER) as a percent of baseline values after various interventions during 90 minutes of circulatory arrest at 20°C. Only limited recovery of the brainstem auditory evoked potential occurred even after antegrade cerebral perfusion (ACP), and there were no significant differences after different interventions. (HCA-HP = circulatory arrest with the head packed in ice; RCP = conventional retrograde perfusion; RCP-O = retrograde perfusion with the inferior vena cava occluded.)
The Annals of Thoracic Surgery  , 38-50DOI: ( /S (98) )