The Journal of thoracic and cardiovascular surgery
-
J. Thorac. Cardiovasc. Surg. · May 1995
pH strategies and cerebral energetics before and after circulatory arrest.
The pH-stat strategy compared with the alpha-stat strategy provides more rapid recovery of brain high-energy phosphate stores and intracellular pH after 1 hour of hypothermic circulatory arrest in pigs. Possible mechanisms for this difference are (1) improved oxygen delivery and homogeneity of brain cooling before deep hypothermic circulatory arrest and (2) greater cerebral blood flow and reduced reperfusion injury owing to extracellular acidosis during the rewarming phase. To identify which of these mechanisms is predominant, we studied 49 4-week-old piglets undergoing 1 hour of deep hypothermic circulatory arrest. ⋯ Recovery of cerebral intracellular pH in the initial 30 minutes was faster in group pH/pH compared with that in group alpha/alpha (p = 0.026). Intracellular pH became more acidic during early reperfusion only in group alpha/alpha, whereas it showed continuous recovery in the other groups. This study suggests that there are mechanisms in effect during both the cooling and rewarming phases before and after deep hypothermic circulatory arrest that could contribute to an improved cerebral outcome with pH-stat relative to more alkaline strategies.
-
J. Thorac. Cardiovasc. Surg. · May 1995
Midline one-stage complete unifocalization and repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals.
Traditionally patients with pulmonary atresia, ventricular septal defect, diminutive or absent central pulmonary arteries, and multiple aortopulmonary collaterals have been managed by staged procedures necessitating multiple operations. We have taken a different approach to this lesion. Between August 1992 and March 1994, ten patients aged 1.43 months to 37.34 years (median 2.08 years) at the severe end of the morphologic spectrum of this lesion underwent a one-stage complete unifocalization and repair from a midline sternotomy approach. ⋯ One other patient underwent balloon dilation of the reconstructed right pulmonary artery, with a good result. All survivors (9/10) are clinically doing well. This approach establishes normal cardiovascular physiology early in life, eliminates the need for multiple systemic-pulmonary artery shunts and use of prosthetic material, and minimizes the number of operations required.(ABSTRACT TRUNCATED AT 400 WORDS)
-
J. Thorac. Cardiovasc. Surg. · Apr 1995
The Norwood operation and subsequent Fontan operation in infants with complex congenital heart disease.
From April 1987 to September 1993, 60 infants underwent a Norwood operation for complex congenital heart disease including hypoplastic left heart syndrome (n = 41), ventricular septal defect and subaortic stenosis with aortic arch interruption/severe coarctation (n = 7), complex single right ventricle with subaortic stenosis (n = 8), critical aortic stenosis with endocardial fibroelastosis (n = 2), and malaligned primum atrial septal defect with coarctation (n = 2). Age at operation ranged from 1 day to 3.9 months (mean 9 days, median 3.5 days). The operative mortality (< 30 days) was 33% (20 patients). ⋯ After we instituted a protocol that adds carbon dioxide to the inspired gas during postoperative mechanical ventilation, the postoperative course became more stable and there have been no operative deaths. In summary, the operative mortality for the Norwood operation continues to improve. A subsequent Fontan operation can be performed with excellent clinical results.
-
J. Thorac. Cardiovasc. Surg. · Apr 1995
Randomized Controlled Trial Comparative Study Clinical TrialIntermittent antegrade warm cardioplegia reduces oxidative stress and improves metabolism of the ischemic-reperfused human myocardium.
The aim of this study was to compare the effect of intermittent antegrade warm blood cardioplegia and intermittent antegrade cold blood cardioplegia on myocardial metabolism and free radical generation of the ischemic-reperfused human myocardium. Thirty patients undergoing mitral valve procedures were randomly allocated to two groups: group 1 (15 patients) received warm blood cardioplegia and group 2 (15 patients), cold blood cardioplegia. Myocardial metabolism was assessed before aortic clamping, 1 minute after crossclamp removal, and after 20 minutes of reperfusion, by collecting blood simultaneously from the radial artery and coronary sinus. ⋯ No significant release of elastase from the coronary sinus was noted in the two groups throughout the study. The left ventricular stroke work index measured at the end of the study indicated a better functional recovery in group 1 than in group 2. In conclusion, intermittent antegrade warm blood cardioplegia protects the myocardium from ischemia-reperfusion injury better than intermittent antegrade cold blood cardioplegia; this phenomenon may be partly due to the decreased tissue oxidant burden mediated by intermittent warm blood cardioplegia.