The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Feb 1990
Is protection of ischemic neonatal myocardium by cardioplegia species dependent?
Hypothermia combined with pharmacologic cardioplegia protects the globally ischemic adult heart, but this benefit may not extend to children, resulting in poor postischemic recovery of function and increased mortality. The relative susceptibilities to ischemia modified by hypothermia alone and by hypothermia plus cardioplegia were assessed in isolated perfused neonatal (3- to 4-day-old) rabbit and pig hearts. Hearts were perfused aerobically with Krebs buffer solution in the working mode for 30 minutes and aortic flow was recorded. ⋯ We conclude that the neonatal pig heart is more susceptible to ischemia modified by hypothermia alone than the neonatal rabbit and that St. Thomas' Hospital solution No. 2 improves postischemic recovery of function in the neonatal pig but decreases it in the neonatal rabbit. This species-dependent protection of the neonatal heart may be related to differences in the extent of myocardial maturity at the time of study.
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J. Thorac. Cardiovasc. Surg. · Jan 1990
Effects of pulsatile perfusion on plasma catecholamine levels and hemodynamics during and after cardiac operations with cardiopulmonary bypass.
Thirty patients scheduled for elective coronary artery bypass grafting were studied in two groups. Group A had standard cardiopulmonary bypass with nonpulsatile perfusion and group B had pulsatile perfusion. Measurements of plasma epinephrine, norepinephrine, granulocyte elastase, and hemodynamic parameters including mean arterial pressure total peripheral resistance, cardiac index, and pulmonary capillary wedge pressure were made before and after anesthesia induction, after surgical incision, during cardiopulmonary bypass, and 2, 4, and 24 hours after the operation. ⋯ The average postoperative tracheal intubation time was also significantly longer in group A than in group B (4.6 +/- 1.2 hours versus 2.7 +/- 0.8 hours, p less than 0.001). No significant difference was detected in either hemoglobin or plasma free hemoglobin content between the two groups postoperatively. The results suggest that pulsatile perfusion, when compared with nonpulsatile perfusion, can attenuate the catecholamine stress response to cardiopulmonary bypass, reduce the fluid overloading of patients, and improve the postoperative recovery period as evaluated by tracheal intubation time.
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J. Thorac. Cardiovasc. Surg. · Dec 1989
Clinical and hemodynamic performance of the Ionescu-Shiley valve in the small aortic root. Results in 117 patients with 17 and 19 mm valves.
The Ionescu-Shiley pericardial valve was our bioprosthetic valve of choice between 1981 and 1985 for patients in whom the aortic anulus could not accept a valve larger than 19 mm in outer diameter or in whom the avoidance of warfarin sodium (Coumadin) was important. A series of 117 consecutive patients who received 17 or 19 mm valves for isolated aortic valve replacement or aortic valve replacement combined with coronary artery bypass grafting or other valvular procedures was analyzed. Overall, 74% of the patients were female, with a mean age of 70.9 years and a body surface area of 1.67 +/- 0.19 m2; 92.3% were in New York Heart Association class III-IV, and the operation was urgent or emergent in 46%. ⋯ The maximum instantaneous gradient was 25 +/- 17.2 mm Hg for 17 mm and 17.41 +/- 5.4 mm Hg for 19 mm valves at late follow-up. The effective orifice area was 0.85 +/- 0.1 cm2 for 17 mm and 1.21 +/- 0.21 cm2 for 19 mm valves. This study defines the normal range of Doppler echocardiographic transprosthetic gradients for the Ionescu-Shiley valve and confirms that low operative mortality and excellent clinical improvement can result from the use of small Ionescu-Shiley valves in elderly patients despite moderate postoperative transvalvular gradients.
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J. Thorac. Cardiovasc. Surg. · Dec 1989
Comparative StudyComparison of three cardioplegic solutions during hypothermic ischemic arrest in neonatal blood-perfused rabbit hearts.
Inadequate myocardial preservation continues to be an important cause of postoperative morbidity and mortality after pediatric cardiac operations. To investigate methods of improving preservation in neonatal myocardium, we compared three cardioplegic solutions with topical hypothermia during 120 minutes of ischemic arrest in isolated, blood-perfused, neonatal rabbit hearts. Topical hypothermia (15 degrees C) without cardioplegia resulted in 71% +/- 5% recovery of preischemic contractile function. ⋯ Thomas' Hospital and Hôpital Lariboisiere cardioplegic solutions resulted in recoveries of 89% +/- 6% and 88% +/- 7%, respectively, both of which were significantly greater (p less than 0.001) than recoveries obtained with the high potassium solution or hypothermia alone. Thus the cardioplegic solutions used at St. Thomas' Hospital and Hôpital Lariboisiere provided excellent protection during 2 hours of hypothermic ischemic arrest in neonatal rabbit hearts and resulted in functional recovery superior to that achieved with hypothermia alone or with the high potassium cardioplegic solution.
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J. Thorac. Cardiovasc. Surg. · Dec 1989
Wound complications after median sternotomy. Relationship to internal mammary grafting.
Case histories of 2582 patients requiring median sternotomy for coronary artery bypass grafting between January 1982 and August 1986 were retrospectively reviewed. Only saphenous vein grafts were used in 230 patients, one mammary artery graft was used in 1626 patients, and both mammary arteries were used in 726 patients. The relationship of potential risk factors and wound complication was evaluated. ⋯ Bilateral mammary grafting increased the chance of wound complication nearly five times that of saphenous vein grafting and three times that of single mammary grafting. Mammary artery grafts have been shown to achieve greater long-term patency than saphenous vein grafts, and their continued use is encouraged. However, the potential for increased wound problems should be considered along with other significant preoperative risk factors such as insulin-dependent diabetes, chronic pulmonary disease, and obesity.