Comparison of Retrograde Cerebral Perfusion to Antegrade Cerebral Perfusion and Hypothermic Circulatory Arrest in a Chronic Porcine Model

Abstract

Retrograde cerebral perfusion (RCP) is a new method of cerebral protection that has been touted as an improvement over hypothermic circulatory arrest (HCA). However, RCP has been used clinically for durations and at temperatures that are “safe” for HCA alone. This study was designed to compare RCP to HCA and antegrade cerebral perfusion (ACP) deliberately exceeding “safe” limits, in order to determine unequivocally whether RCP provides better cerebral protection than HCA. Four groups of six Yorkshire pigs (20 to 30 kg) were randomly assigned to undergo 90 minutes of RCP, ACP, HCA, or HCA with heads packed in ice (HCA‐HP) at an esophageal temperature of 20°C. Arterial, mixed venous and cerebral venous oxygen, glucose and lactate contents; quantitative EEG; were monitored at baseline (37°C); at the end of cooling cardiopulmonary bypass (20°C); during rewarming (30°C); and at two and four hours post intervention. Animals were recovered and were evaluated daily using a quantitative behavioral score (0 to 9). Mean behavioral score was lower in the HCA group than in the other three groups at seven days (HCA 5.8 ± 1.1; RCP 8.5 ± 0.2; ACP 9.0 ± 0.0; HCA‐HP 8.5 ± 0.2, p < 0.05). Recovery of QEEG was better in the ACP group than in all others, but the RCP group had faster EEG recovery than HCA alone, although not better than HCA‐HP (HCA 15 ± 4; RCP 27 ± 3; ACP 78 ± 5; HCA‐HP 19 ± 3, p < 0.001). However, histopathological evidence of ischemic injury was present in 5 of 6 HCA animals and also in 4 of 6 of the HCP‐HP group, but only In 1 of 6 RCP animals and in none of the ACP group. This study demonstrates that ACP affords the best cerebral protection by all outcome measures, but RCP provides clear improvement compared to HCA. (J Card Surg 1994;9:560–575)

Neurobehavioral functional deficits following closed head injury in the neonatal pig

“…Typically a series of 4 or 5 categories of neurological function are used (e.g. mental status, cranial nerves, sensorimotor function, feeding), each of which is assigned a graded score of 1-4 representing the degree of abnormality, yielding a final score ranging from a possible total of 9 for the simplest grading scheme (Midulla 1994), to 150 for a more complicated neurological deficit score (Agnew 2003). These grading systems have shown only limited correlation with histopathologic abnormalities (Priestley 2001), but their sensitivity for assessment of complex behavior or cortical functions is poor, and none have been well validated with long-term survival studies.…”

Is it worth packing the head with ice in patients undergoing deep hypothermic circulatory arrest?

“…Midulla et al [6] randomized 28 pigs into one of four groups: HCAA, HCA-HP, RCA or ACP. All animals were placed on CPB and cooled to 20°C, before undergoing their randomized intervention for 90 min, then rewarmed to 30°C.…”

Analysis of risk factors affecting mortality in proximal aortic surgery

“…[1,3,8,12] Buna rağmen güvenli ısı aralığında halen kesin bir görüş birliği sağlanamamıştır. [13][14][15][16][17][18] Bazı çalışmalarda optimal ısıların 18 °C -22 °C'ye yükseltilebileceği belirtmiştir. [4,[19][20][21] Kliniğimizde özellikle diseksiyon hastalarında daha güvenli bulduğumuz, 16 °C -18 °C derin hipotermi aralığı tercih edilmekteyken, antegrad selektif serebral perfüzyon uygulanan hastalarda brakiyosefalik artere klemp sonrası açık distal teknik ile güvenli distal anastomoz uygulanmaktadır.…”