The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Mar 1989
Comparative StudyBrain tissue pH, oxygen tension, and carbon dioxide tension in profoundly hypothermic cardiopulmonary bypass. Comparative study of circulatory arrest, nonpulsatile low-flow perfusion, and pulsatile low-flow perfusion.
The pH, oxygen tension, and carbon dioxide tension of canine brain tissue were experimentally examined during profoundly hypothermic cardiopulmonary bypass. After core cooling, a 60-minute period of circulatory arrest was performed in group 1 (n = 8), a 120-minute nonpulsatile low-flow perfusion (25 ml/kg/min) in group 2 (n = 8), and a 120-minute pulsatile low-flow perfusion (25 ml/kg/min) in group 3 (n = 8). When the animal was rewarmed, the core temperature was raised to 32 degrees C. ⋯ Brain tissue carbon dioxide tension increased irreversibly in group 1, increased to about 100 mm Hg and recovered to 89.9 +/- 15.3 mm Hg in group 2, and reached a plateau of about 85 mm Hg and recovered to 55.4 +/- 6.7 mm Hg in group 3. We concluded that a 120-minute period of nonpulsatile low-flow perfusion provides more protection from brain damage than a 60-minute period of circulatory arrest. Furthermore, pulsatile flow will increase the safety margin of cardiopulmonary bypass even if the flow rate is reduced to 25 ml/kg/min.
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J. Thorac. Cardiovasc. Surg. · Mar 1989
Clinical Trial Controlled Clinical TrialReduction in blood loss and blood use after cardiopulmonary bypass with high dose aprotinin (Trasylol).
The effect of high dose aprotinin (Trasylol) was evaluated in three groups of patients undergoing cardiopulmonary bypass. In a prospective, placebo-controlled, double-blind study, 80 patients having primary aorta-coronary bypass grafting received aprotinin (700 mg approximately) or saline placebo from the beginning of the procedure until skin closure. Standardized anesthetic, perfusion, and surgical techniques were used. ⋯ At day 7 the values were 13.1 +/- 1.4 gm/dl versus 12.5 +/- 1.2 gm/dl in the aprotinin group and the placebo group, respectively. Platelet counts determined at fixed times perioperatively did not differ between the two groups. In contrast, template bleeding time measured in 32 study patients was distinctly different between groups, with a postoperative rise of 6.2 +/- 2.1 minutes in the placebo group opposed to only 1.5 +/- 1.1 minutes in the aprotinin group.(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Thorac. Cardiovasc. Surg. · Mar 1989
Experiments with a bowl of saline: the hidden risk of hypothermic-osmotic damage during topical cardiac cooling.
Some of the misconceptions in the application of cardiac hypothermia are that the temperature of cold normal saline solution is necessarily above 0 degrees C, cold saline solution and slush are relatively safe for living tissues, and normal saline will retain normal osmolality even if partially frozen. These postulates were examined in thermodynamic experiments that demonstrated three points: (1) The temperature of unfrozen saline solution may drop way below the freezing point. (2) When liquids and solid components of saline solution are separated, the components will become hypo-osmolar or hyperosmolar. (3) Ice chips and slush ice produced in the operating rooms may reach temperatures as low as -36 degrees C. We recommend that the possibility of these events should be taken into consideration whenever topical cardiac hypothermia is clinically applied.
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In a survey of 142 hospitals in Japan, 1562 operations involving tracheobronchoplasty, 565 involving tracheoplasty, and 992 involving bronchoplasty were found to have been done from 1954 to 1984. The number of operations showed a steep increase from 1965 and reached more than 200 a year by 1984. This increase comes from larger numbers of bronchoplasty procedures being performed for lung cancer (58.8% in toto) and of tracheoplasty procedures for thyroid cancer (9.7% in toto). ⋯ The tracheal anastomosis mode was classified into two categories, standard and extensive. The latter showed complication rates higher than the former (p less than 0.01), tracheoplasty (p less than 0.0025), and the tracheal anastomosis stem mode (p less than 0.0025). Complication rates have decreased with time, being 21.8% with the tracheal anastomosis mode and 10.8% with the bronchial anastomosis mode in the past 9 years.
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From May 1983 to July 1987 a total of 153 Hancock II porcine bioprostheses have been implanted in 130 patients with a mean age of 59 +/- 8 years (range 29 to 76 years). Mitral valve replacement was performed in 72 patients, aortic valve replacement in 35, and mitral-aortic valve replacement in 23. Cumulative follow-up of 121 survivors is 223 patient-years and 100% complete (range 0.4 to 4.5 years). ⋯ Failure of the porcine bioprosthesis was observed in three patients with an actuarial freedom at 4 years of 96% +/- 3.6% for aortic, 91% +/- 8% for mitral, and 91% +/- 8.6% for mitral-aortic valve replacement. Actuarial freedom from all porcine bioprosthesis-related complications at 4 years is 85.7% +/- 6.6% for aortic, 79% +/- 9% for mitral, and 70% +/- 13% for mitral-aortic valve replacement. No instances of primary tissue failure occurred.(ABSTRACT TRUNCATED AT 250 WORDS)