To evaluate the effect of hypothermic circulatory arrest on brain metabolism, we used
31P-magnetic resonance spectroscopy to monitor brain metabolites in pigs during 2 hours of ischemia and 1 hour of ...reperfusion. Twenty-eight pigs were divided into five groups. Anesthesia (
n=5) and hypothermic cardiopulmonary bypass groups (
n=5) served as controls. In the circulatory arrest (
n=6), antegrade perfusion (
n=6), and retrograde (
n=6) brain perfusion groups, the bypass flow rate was 60 to 100 ml·kg
−1·min
−1. In the antegrade group, the brain was perfused via the carotid arteries at a blood flow rate of 180 to 200 ml·min
−1 during circulatory arrest at 15° C. In the retrograde group, the brain was perfused through the superior vena cava at a flow rate of 300 to 500 ml·min
−1 during circulatory arrest at 15° C. The intracellular pH was 7.1±0.1 and 7.3±0.1 in the anesthesia and hypothermic cardiopulmonary bypass groups, respectively. In the circulatory arrest group, the intracellular pH decreased to 6.2±0.1 and did not recover to its initial value (7.0±0.1) during reperfusion (
p<0.05 compared with the value obtained from the control groups at the corresponding time). Inorganic phosphate did not return to its initial level during reperfusion. In three animals in this group, levels of high-energy phosphates, adenosine triphosphate and phosphocreatine, recovered partially but did not reach the levels observed before arrest. In the group receiving antegrade perfusion, cerebral metabolites and intracellular pH were unchanged throughout the protocol. During circulatory arrest in the retrograde perfusion group the intracellular pH decreased to 6.4±0.1 and recovered fully during reperfusion (7.1±0.1). High-energy phosphates also returned to their initial levels during reperfusion. These studies show that deep hypothermic circulatory arrest with antegrade brain perfusion provides the best brain protection of the options investigated.
A stentless pericardial aortic monopatch was used in 60 consecutive patients undergoing aortic valve replacement. The monopatch is constructed of a sheet of glutaraldehyde-treated bovine pericardium, ...tailored and shaped to fit the aortic anulus, and is sutured in place without a stent or sewing ring. The valve area is effectively preserved by this method. Results indicate that this technique is simple, inexpensive, and applicable to all cases of aortic valve disease. It does not require anticoagulation and may allow for annular growth when used in children. This technique is particularly suitable for patients with infective endocarditis because the amount of foreign material is minimized.
Book Reviews Aalbers, Jasper; Berry, Michael; Briley, Ron ...
Historical Journal of Film, Radio and Television,
20/3/1/, Letnik:
32, Številka:
1
Book Review
Book Reviews Aalbers, Jasper; Berry, Michael; Briley, Ron ...
Historical Journal of Film, Radio and Television,
03/2012, Letnik:
32, Številka:
1
Book Review
PDF
