Cardiovascular surgery (London, England)
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Comparative Study
Low-potassium University of Wisconsin solution for cardioplegia: improved protection of the isolated ischemic neonatal rabbit heart.
Recovery of cardiac function and high-energy phosphates following ischemia and reperfusion were determined for hearts perfused with low potassium University of Wisconsin solution, high potassium University of Wisconsin solution, St Thomas' solution, or subjected to hypothermia alone. Isolated hearts were arrested for either 3 h at 15 degrees C or 6 h at 20 degrees C (n = 7 for each group) with one of the four solutions and then reperfused. ⋯ Myocardial adenosine triphosphate and creatine phosphate after reperfusion tended to be higher in the low potassium University of Wisconsin solution group. It is concluded that low potassium University of Wisconsin solution may provide reliable cardioplegia during surgery that requires prolonged cardiac arrest in neonates and infants.
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There remains no consensus on the operative management of Thoracoabdominal aortic aneurysm (TAA). Our approach emphasizes operative expediency and simplicity (without circulatory assist techniques), avoiding anticoagulation and systemic hypothermia. ⋯ In a cohort of over 200 TAA patients (50% Types I & II) treated during the past decade perioperative mortality has been 8% and paraparesis/paraplegia occured in 7%. These figures are halved for patients treated in elective circumstances.
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A systematic approach to paraplegia risk in the surgical treatment of thoracoabdominal aortic aneurysms based on effective strategies identified from the experimental literature is discussed. With this approach, collateral blood flow, rather than direct intercostal reimplantation, moderate hypothermia and endorphin receptor, is emphasized blockade. The result has been a 10-fold reduction in paraplegia risk in elective patients and a 5-fold reduction in acute patients. This reduction in paralysis risk has resulted in improved short- and long-term survival.
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Aneurysms that extend from the descending thoracic aorta into the abdomen and also those that involve the visceral segments of the upper abdominal aorta are traditionally classified as thoracoabdominal. Besides the surgical exposure difficulties associated with repair of these aneurysms, the temporary interruption of renal, splanchnic, and perhaps even spinal cord flow introduces a number of potential complications that makes surgical repair of these aneurysms a daunting task. The exact incidence of thoracoabdominal aneurysms is unknown, but population studies suggest a prevalence at least a log fold less than the more common infrarenal abdominal aortic aneurysm. ⋯ Spinal cord ischemia remains a perplexing and devastating complication following thoracoabdominal aneurysm repair. A number of surgical adjuncts have been developed over the years to reduce the incidence of cord ischemic complications, yet a great deal of controversy still exists with regards to the optimal protective strategy. A description of the incidence, natural history, and classification of thoracoabdominal aneurysms, along with associated repair techniques centered on reducing spinal cord ischemic complications will form the basis for this review.
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Randomized Controlled Trial Comparative Study Clinical Trial
Myocardial beta-blockade as an alternative to cardioplegic arrest during coronary artery surgery.
The authors' recent experimental work has demonstrated that myocardial protection using continuous coronary perfusion with warm beta-blocker-enriched blood avoids myocardial ischaemia and minimizes myocardial oedema formation, thus completely preserving left ventricle function. The purpose of this clinical study was to compare this alternative technique in terms of structural and functional myocardial protection with the routinely used crystalloid Bretschneider cardioplegia. Sixty coronary artery surgery patients were randomized to receive either crystalloid cardioplegia or continuous coronary perfusion with warm blood enriched with the ultra-short acting beta-blocker esmolol. ⋯ The post-cardiopulmonary bypass fractional area of contraction was similar in both groups (beta-blocker: 65 +/- 14%; crystalloid cardioplegia: 62 +/- 16%); however, beta-blocker patients required less inotropic stimulation (dopamine: beta-blocker: 2.9 +/- 2.5 versus crystalloid cardioplegia: 5.0 +/- 2.3 microg/kg per min; P < 0.05). The data suggest that continuous coronary perfusion with warm esmolol-enriched blood results in better myocardial protection compared with crystalloid cardioplegia. It is concluded that the concept of beta-blocker-induced cardiac surgical conditions may be a useful alternative for myocardial protection during coronary artery surgery.