The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Mar 1990
Comparative StudyHeparin dosing and monitoring for cardiopulmonary bypass. A comparison of techniques with measurement of subclinical plasma coagulation.
Subclinical plasma coagulation during cardiopulmonary bypass has been associated with marked platelet and clotting factor consumption in monkeys. To better define subclinical coagulation in man, we measured plasma fibrinopeptide A concentrations before, during, and after cardiopulmonary bypass. Patients were assigned to one of three groups of heparin management: group 1 (n = 10)--initial heparin dose 300 IU/kg, with supplemental heparin if the activated coagulation time fell below 400 seconds; group 2 (n = 6)--initial heparin dose 250 IU/kg, with supplemental heparin if activated coagulation time was less than 400 seconds; and group 3 (n = 5)--initial heparin dose 350 to 400 IU/kg, with supplemental heparin if whole blood heparin concentration was less than or equal to 4.1 IU/ml. ⋯ Group 3 patients received the highest heparin doses (p less than 0.05) and had the greatest postoperative blood loss (p less than 0.05). Protamine dose and heparin concentration during cardiopulmonary bypass correlated best with postoperative mediastinal drainage. Our findings support the following conclusions: (1) compensated subclinical plasma coagulation activity occurs during cardiopulmonary bypass despite activated coagulation time greater than 400 seconds or heparin concentration greater than or equal to 4.1 IU/ml; (2) post-cardiopulmonary bypass mediastinal drainage correlates strongly with increased heparin concentration during cardiopulmonary bypass (p less than 0.05) and protamine dose (p less than 0.05); and (3) during cardiopulmonary bypass at both normothermia and hypothermia, activated coagulation times greater than 350 seconds result in acceptable fibrinopeptide A levels and post-cardiopulmonary bypass blood clotting.
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J. Thorac. Cardiovasc. Surg. · Mar 1990
Improving clinical efficacy of computed tomographic scan in the preoperative assessment of patients with non-small cell lung cancer.
The criterion of choice for computed tomographic scan identification of metastatic mediastinal nodes is not clearly fixed. This prospective study was designed to define the most suitable computed tomographic criterion for detection of nodal metastasis, enabling improvement of the test's clinical efficacy. One hundred twenty-three patients with potentially operable non-small cell lung cancer underwent mediastinal evaluation by computed tomographic scan and cervical mediastinoscopy followed by thoracotomy with mediastinal node dissection. ⋯ When mediastinal nodes were classified as positive, the resectability rate was 55%, 27%, or 13%, respectively. In these instances cervical mediastinoscopy allowed identification of different degrees of mediastinal involvement; it proved to be the most useful procedure for preoperative selection of those patients with N2 tumors who are amenable to a complete resection. In conclusion, the use of computed tomographic criterion 3 does improve the clinical efficacy of the test, by sparing a large number of unnecessary mediastinal explorations, without increasing the rate of useless thoracotomies.
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J. Thorac. Cardiovasc. Surg. · Mar 1990
Single-cannula venovenous bypass for respiratory membrane lung support.
Clinical use of a single cannula would make extracorporeal membrane oxygenation simpler and less aggressive. It would probably limit the occurrence of the complications of currently used techniques (double-cannula, venoarterial, or venovenous bypass). In this experimental study an original system is described that is composed of a single cannula, an alternating clamp, and a nonocclusive roller pump, the characteristics of which permit its use as a venous reservoir. ⋯ Arterial carbon dioxide tension was maintained at normal levels in both types of circuits. Hemodynamic condition was only slightly affected by the alternative flow of the bypass. This system of single-cannula membrane lung support thus seems to be adequate for clinical use.
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J. Thorac. Cardiovasc. Surg. · Mar 1990
Perinodal cryosurgery for atrioventricular node reentry tachycardia in 23 patients.
Atrioventricular node reentry tachycardia is the most common cause of paroxysmal supraventricular tachycardia. Available nonpharmacologic therapies include (1) catheter ablation or cryosurgical ablation of the His bundle and insertion of a permanent pacemaker and (2) surgical dissection around the atrioventricular node or discrete cryosurgery of the perinodal tissues, in an attempt to divide or ablate only one of the dual atrioventricular node conduction pathways responsible for the tachycardia while leaving the other intact. This report describes 23 consecutive patients who underwent the discrete cryosurgical procedure between August 13, 1982, and March 16, 1989. ⋯ Postoperatively, all 23 patients had normal atrioventricular conduction, and no heart block has occurred in any patients during the follow-up period. All patients have remained free of atrioventricular node reentry tachycardia (and of the Wolff-Parkinson-White syndrome) and none has required postoperative antiarrhythmic drugs for either of these arrhythmias. We consider this simple, safe, easily performed, and uniformly successful operation to be the procedure of choice for the treatment of medically refractory atrioventricular node reentry tachycardia.
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J. Thorac. Cardiovasc. Surg. · Mar 1990
The Carpentier-Edwards standard porcine bioprosthesis. A first-generation tissue valve with excellent long-term clinical performance.
The Carpentier-Edwards standard porcine bioprosthesis was implanted in 1190 patients (1201 operations, 1303 valves) between January 1975 and June 1986; most implants were before 1982. The mean age of the patients was 57.2 years (range 8 to 85 years). The early mortality was 7.6% (aortic valve replacement 5.1%, mitral valve replacement 8.8%, and multiple valve replacement 15.3%). ⋯ Freedom at 10 years from thromboembolism was 84.3% for aortic valve replacement and 76.5% for mitral valve replacement (p = 0.05); structural valve deterioration was 78.6% for aortic valve replacement and 71.6% for mitral valve replacement (p less than 0.05); reoperation was 74.4% for aortic valve replacement and 67.1% for mitral valve replacement (p less than 0.05). Freedom from all valve-related complications at 10 years was 58.9% for aortic valve replacement and 46.8% for mitral valve replacement (p less than 0.05); valve-related mortality was 89.5% for aortic valve replacement and 82.6% for mitral valve replacement (p = not significant); mortality and reoperation was 58.9% for aortic valve replacement and 46.8% for mitral valve replacement (p less than 0.05); mortality and residual morbidity (treatment failure) was 87.2% for aortic valve replacement and 75.1% for mitral valve replacement (p = not significant); mortality, residual morbidity, and reoperation were 66.3% for aortic valve replacement and 54.9% for mitral valve replacement (p less than 0.05). The standard Carpentier-Edwards porcine bioprosthesis has provided satisfactory clinical performance and has afforded patients excellent quality of life.