Intracellular adhesion molecule-1 in patients developing pulmonary insufficiency after cardiopulmonary bypass.

OBJECTIVES: Cardiopulmonary bypass activates adhesion molecules, which are associated with systemic inflammation and organ dysfunction. The intracellular adhesion molecule-1 (ICAM-1) has been evaluated in patients presenting pulmonary dysfunction after cardiac surgery. MATERIALS AND METHODS: Postoperative serum levels of the ICAM-1 were measured in 40 patients who underwent isolated coronary artery bypass grafting, in 28 with uneventful postoperative recovery (70 %) (Group 1), and in 12 (30 %) with postoperative respiratory insufficiency (Group 2), defined by the need for prolonged (> 24 hours) mechanical ventilation using a fractional oxygen concentration of > 40 %. RESULTS: Patients in group 1 were ventilated for 12.21 +/- 4.86 hours and those in group 2 for 92.91 +/- 48.14 hours (p < 0.001). ICAM-1 decreased from 145.98 +/- 73.40 ng/ml to 81.15 +/- 114.82 ng/ml in group 1, while in group 2 ICAM-1 showed a significant higher level and increased to 435.01 +/- 130.02 ng/ml (p < 0.001). The leukocyte count increased in both groups as well as the C-reactive protein (CRP) during the postoperative course. The CRP behaves similar in both groups (p = 0.636) in contrast to the leukocyte count which was significantly higher in group 2 (p < 0.01). While none of the patients in group 1 died the mortality in group 2 was 50 % (p < 0.001). CONCLUSION: Respiratory insufficiency after cardiopulmonary bypass is associated with a distinct increase in the ICAM-1. The reason for the increase of the ICAM-1 in this small subset of patients has not been clarified.

Plasma levels of selectins and interleukins in cardiovascular surgery using cardiopulmonary bypass.

BACKGROUND: Cardiovascular surgery with cardiopulmonary bypass (CPB) leads to activation of a variety of inflammatory pathways, including the release of cytokines and selectins. METHODS: In 20 patients undergoing elective coronary artery bypass grafting, plasma levels of interleukins IL-2, -6, -8, -10, -12 and of P-, E-, and L-selectins were measured at eight time points before, during, and after CPB using a standardized ELISA technique. RESULTS: IL-2 plasma levels decreased significantly after the start of CPB and remained low until the second postoperative day. IL-6 and IL-8 levels increased significantly after weaning off CPB, with mean peak values six hours postoperatively. Very low IL-10 plasma levels were detectable preoperatively. They remained low during CPB and peaked significantly after weaning off CPB until skin closure. The IL-12 levels decreased after weaning off CPB (p < 0.05) until 6 hours postoperatively. The plasma levels of P-selectin showed no alterations, but concentrations of E- and L-selectin decreased after the start of CPB (p < 0.05). There were no adverse postoperative events. CONCLUSIONS: The results of our study demonstrate a dysregulation of cytokine and selectin production during and up to 48 h after CPB, which may be a "normal" stress reaction to CPB.

Thrombin generation and activation of the thrombomodulin protein C system in open heart surgery depend on the underlying cardiac disease.

The exposure of blood to foreign surfaces during extracorporeal circulation (ECC) leads to an activation of the coagulation system. In arteriosclerotic patients thrombin activation is increased and plasma fibrinogen is elevated, while protein C levels are reduced. In this study we investigated the influence of different cardiac diseases on ECC-induced thrombin generation and activation of the thrombomodulin-protein C system. Twenty-four patients undergoing either elective coronary artery bypass grafting (CABG) or elective aortic valve replacement (AVR) were included in the study. Blood samples were taken at different time intervals before, during and after ECC, and in the postoperative period. Plasma concentrations of thrombin-antithrombin III-complex (TAT), modified antithrombin (ATM), prothrombin fragment F1+2, free protein S, thrombomodulin, and protein C-antigen were determined by ELISA. Fibrinogen and antithrombin III levels were detected by nephelometry. Both groups were comparable with respect to biometric and ECC-related data. TAT concentrations were elevated in both groups after induction and increased during surgery (p<0.001). As a marker of thrombin generation levels of F1+2 were higher in the CABG group during cardiopulmonary bypass (p=0.003). In CABG patients ATM peaks were higher during ECC (p=0.0024). Significantly higher plasma thrombomodulin concentrations were found in CABG patients after induction (p<0.001), while protein S concentrations were higher in the AVR group (p=0.002). Protein C levels and antithrombin III concentrations did not differ between the groups. Patients undergoing CABG were found to have lower protein S levels and increased plasma thrombomodulin concentrations as markers of endothelial damage. In these patients contact activation and as a consequence thrombin generation takes place at a higher level, indicating a hypercoagulable state. Thromboembolic events in the perioperative period may be caused by different hemostatic changes in CABG patients.

Acute phase and opsonin response in cardiac surgery patients: influence of underlying cardiac disease.

Cardiopulmonary bypass (CPB) leads to an activation of plasma cascade systems, complement activation, and an acute phase response. To evaluate the influence of the underlying cardiac disease on the activation pattern of these systems, we compared inflammatory changes in coronary artery bypass grafting (CABG) patients with patients undergoing aortic valve replacement. We investigated changes of the acute phase proteins alpha 1-proteinase inhibitor and fibrinogen, the unspecific opsonin fibronectin, and the complement components C3c and C4 induced by extracorporeal circulation in 12 patients undergoing aortic valve replacement and in 12 patients undergoing CABG. Concentrations of C3c and C4 decreased in both groups after the onset of CPB and C4 concentration remained below post-induction levels up to 24 h after onset of CPB (p = 0.04). Fibronectin levels dropped immediately before the onset of CPB (p = 0.01), reaching the lowest values after 20 min of extracorporeal circulation. Fibrinogen and alpha 1-proteinase inhibitor levels after induction of anaesthesia were significantly higher in the CABG group and remained higher throughout the entire study period (p < 0.001). As an indicator of a postoperative acute phase response, concentrations of both proteins rose in the postoperative period above post-induction levels (p < 0.02).

Alterations of the cytokine network in patients undergoing cardiopulmonary bypass.

Cardiovascular surgery using extracorporeal circulation causes a systemic inflammatory response which often results in severe organ dysfunction and increased postoperative mortality. Advances in knowledge about the interactions of cytokines involved in the response to cardiopulmonary bypass (CPB) may improve the outcome of patients undergoing cardiac surgery. The purpose of our study was to investigate the fluctuations in cytokine production, during and after CPB. In 24 patients undergoing elective coronary artery bypass grafting, plasma levels of interleukins IL-2, IL-6, IL-10 and IL-12, soluble IL-2-receptor (sIL-2R), and transforming growth factor-beta (TGF-beta) were measured at eight time points before, during and after CPB, using a standardized enzyme-linked immunosorbant assay technique. There was a significant increase in plasma levels of IL-10, IL-6 and TGF-beta after weaning off CPB. The IL-2 plasma levels decreased after the onset of CPB until 24 h postoperatively (p < 0.05). Concentrations of sIL-2R decreased 20 min after the start of CPB until the end of the operation (p < 0.05). In the postoperative course, sIL-2R levels increased, with peak values 48 h after the end of the surgical procedure. The IL-12 levels decreased after weaning off CPB (p < 0.05) until 6 h postoperatively. The results of our study demonstrate an intraoperative-predominant immunosuppression, followed by an early postoperative immunological activation, combined with a distinct acute phase response.

Concentration of cefamandole in plasma and tissues of patients undergoing cardiac surgery: the influence of different cefamandole dosage.

OBJECTIVE: To develop an improved regimen of antibiotic prophylaxis in cardiac surgery, three antibiotic prophylactic regimens for patients scheduled to have elective cardiothoracic surgery involving a median sternotomy were evaluated. DESIGN: A prospective, randomized, unblinded study. SETTING: A university teaching hospital. PARTICIPANTS: Sixty-nine men scheduled for elective coronary artery bypass grafting (CABG) with extracorporeal circulation (ECC) were included in the study. INTERVENTIONS: The patients were selected at random to receive 2 g of cefamandole (CM) at induction of anesthesia (group 1, n = 24), or 2 g of CM at the beginning of anesthesia followed by an additional dose (2 g) immediately after onset of cardiopulmonary bypass (CPB) (group 2, n = 22), or 4 g of CM just at the initiation of anesthesia (group 3, n = 23). Samples from the mammary artery, sternum, and plasma were obtained at various intervals after injection of the antibiotic (10 minutes intravenously) to compare antibiotic levels, assayed for CM concentrations, with high-pressure liquid chromatography (HPLC) and plasma bactericidal activity as well as infectious complications in these sites as a function of time for the three groups. MEASUREMENTS AND MAIN RESULTS: There were no significant differences in biometric data, duration of hospitalization, or management of cardiopulmonary bypass, including urinary tract drainage and infusion volume. The mean plasma t1/2 (distributive or alpha-phase) before bypass was 51.7 +/- 16.7 minutes for group 1 and 2 patients and 54.9 +/- 15.9 minutes for group 3 patients. CM plasma values were significantly higher in group 2 (170.3 +/- 105.8 micrograms/mL) than in groups 1 and 3 (111.8 +/- 42.2 micrograms/mL, 101.2 +/- 57.2 micrograms/mL) at the end of bypass periods (p < 0.05). The antibiotic contents of mammary artery and sternum samples of group 2 (15.6 +/- 4.7 micrograms/mL, 9.5 +/- 4.7 micrograms/mL) were significantly higher after completion of CPB compared with group 1 (5.7 +/- 1.9 micrograms/mL, 3.8 +/- 2.9 micrograms/mL) and group 3 (6.3 +/- 3.5 micrograms/mL, 3.6 +/- 1.8 micrograms/mL) (p < 0.05). There were no significant differences in distribution of micro-organisms among the three groups, but two patients of groups 1 and 3 with plasma and tissue CM levels below minimal inhibitor concentration (MIC90) for Hemophilus influencea, E coli, Proteus ssp and Klebsiella ssp after completion of CPB, respectively, developed a pneumonia postoperatively caused by Hemophilus influencea (1), E coli (1) and Klebsiella ssp (2) (p < 0.05). CONCLUSIONS: It would be preferable to infuse the antibiotic shortly before the operative procedure. However, to keep tissue and plasma CM values more than MIC90 for common pathogens during the time period studied, a second infusion of 2 g of CM administered after onset of CPB suggests better protection against the risk of microbial infections. Therefore, the findings might be important for the choice of antibiotic prophylaxis, particularly for high-risk patients.

Plasma levels of immunoinhibitory cytokines interleukin-10 and transforming growth factor-beta in patients undergoing coronary artery bypass grafting.

OBJECTIVE: Cardiovascular surgery with extracorporeal circulation causes a systemic inflammatory response, which can lead to organ failure and increased postoperative morbidity. Advances in knowledge about the interactions between markers of cellular and humoral immunity involved in the inflammatory response to cardiopulmonary bypass (CPB) may reduce the deleterious effects and improve the outcome for patients undergoing cardiac surgery. METHODS: To determine the release of immunoinhibiting cytokines during CPB, we measured plasma levels of interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta) in 30 patients undergoing elective coronary artery bypass grafting. Arterial blood samples were collected at eight time points before, during and after CPB, using a standardized ELISA-technique. RESULTS: Plasma IL-10 and TGF-beta increased significantly after weaning off CPB (P < 0.05) and peaked respectively at time of skin closure (IL-10, 308 +/- 180 pg/ml; TGF-beta, 1860 +/- 906 pg/ml; mean peak +/-S.D.). Postoperatively, 6 h, IL-10 decreased to 19.8 +/- 9.8 pg/ml (P < 0.05) and TGF-beta decreased to 1133 +/- 547 pg/ml (P < 0.05). CONCLUSIONS: Both cytokines are major immunoregulatory factors with negative influence on T cell-mediated immunologic response. The significantly elevated levels at the end of CPB indicate that IL-10 and TGF-beta may be important factors of immunologic dysregulation following CPB.

Can clonidine, enoximone, and enalaprilat help to protect the myocardium against ischaemia in cardiac surgery?

OBJECTIVE: To evaluate whether clonidine, enoximone, and enalaprilat reduce ischaemia-related myocardial cell damage in cardiac surgery. DESIGN: Prospective randomised controlled trial. SETTING: Clinical investigation in a cardiac anaesthesia department of a university hospital. PATIENTS: 88 consecutive patients undergoing coronary artery bypass surgery. INTERVENTIONS: After induction of anaesthesia patients continuously received the alpha 2 agonist clonidine (group 1, n = 22), the phosphodiesterase (PDE) III inhibitor enoximone (group 2, n = 22), the angiotensin converting enzyme (ACE) inhibitor enalaprilat (group 3, n = 22), or saline solution as placebo (control group, n = 22). The infusion was stopped immediately before the start of cardiopulmonary bypass. MAIN OUTCOME MEASURES: The ST segment was analysed and the activity of creatine kinase isoenzyme MB (CKMB), cardiac troponin T (TnT), and the BB isoenzyme of glycogen phosphorylase (GPBB) were measured before the start of infusion (baseline), after weaning from cardiopulmonary bypass (CPB), at the end of surgery, 5 h after CPB, and on the morning of the first and third postoperative days. RESULTS: Biometric data and time of cross-clamping were not significantly different in the four groups. Changes in the ST segment indicating ischaemia were least common in the enalaprilat group (P < 0.05). Postoperatively, CKMB activity was significantly higher in the clonidine and the control groups. Both new markers of myocardial cell damage increased more after CPB and postoperatively in the control patients (TnT peak: (mean (SD)) 3.99 (0.35) microgram/1; GPBB peak: 82 (15) ng/ml) and the clonidine-treated group (TnT peak: 3.80 (0.3) microgram/1; GPBB peak: 85 (14) ng/ml). Enalaprilat-treated patients showed the smallest overall changes in standard (CKMB) and new serological markers of myocardial ischaemia (TnT peak: 0.71 (0.1) microgram/1; GPBB peak: 44 (14) ng/ml). CONCLUSIONS: In patients treated with enalaprilat before CPB, both new, more sensitive markers of ischaemic myocardial tissue damage increased significantly less than in an untreated control group. Those treated with enoximone also had lower plasma concentration of TnT and GPBB than the control group, whereas clonidine did not reduce the concentration of these markers of myocardial ischaemia. Pharmacological interventions, such as the continuous infusion of the ACE inhibitor enalaprilat, before start of CPB may help to protect the heart against ischaemia/reperfusion injury.

Perioperative microbiologic monitoring of tracheal aspirates as a predictor of pulmonary complications after cardiac operations.

The value of preoperative and early postoperative microbiologic testing of tracheal aspirates as a prognostic indicator of the development of pneumonia was evaluated in a prospective study of 213 cardiac surgical patients. Tracheal aspirates were obtained immediately after intubation and after the patient's arrival at the intensive care unit. Diagnosis of pneumonia was accepted if at least three of the following criteria were fulfilled: leukocytosis > 15,000 cells/mm3, body temperature >38.5 degrees C, positive results of auscultation, positive results of radiography (new infiltrates that seemed to be consistent with pneumonia), and increased core-reactive protein for more than 2 days after operation. Potentially pathogenic microorganisms were found in 54 (25.4%) of the preoperative tracheal aspirates and in 27 (12.7%) of the early postoperative tracheal aspirates. Positive microbiologic findings correlated with pneumonia in the postoperative course in 24.1% (p < 0.001) if the preoperative culture results were positive, in 48.2% (p < 0.001) if the postoperative culture results were positive, and in 44.0% (p < 0.001) if both were positive. The risk of pneumonia was increased in male patients (p < 0.05) and in patients with chronic obstructive pulmonary disease (p < 0.05). Demographic variables, smoking, acute pulmonary symptoms, temperature, leukocyte count at the day of the operation, and data on the operation and the extracorporeal circulation were not significantly related to pneumonia in the early postoperative course. The risk of development of postoperative pneumonia is significantly higher among patients with colonization of the lower respiratory tract. Positive culture results in routine microbiologic monitoring of tracheal aspirates are predictive of pulmonary complications after cardiac operations.

Hypothermic versus normothermic cardiopulmonary bypass: influence on circulating adhesion molecules.

OBJECTIVE: Cardiopulmonary bypass (CPB) may result in a whole-body inflammatory response with the risk of subsequent development of organ failure. Leukocyte-endothelial binding followed by neutrophil migration appear to play a central role. This process is markedly influenced by adhesion molecules. Whether plasma levels of circulating adhesion molecules are beneficially influenced by hypothermic CPB was studied in patients undergoing either hypothermic or normothermic CPB. DESIGN: Prospective, randomized study. SETTING: Single-Institutional, clinical investigation in a cardiac anesthesia department of a university hospital. PARTICIPANTS: 30 patients scheduled for elective aortocoronary artery bypass grafting. INTERVENTIONS: The patients were prospectively and randomly divided into two groups: group 1 underwent hypothermic CPB (rectal temperature 27 to 28 degrees C; n = 15) and group 2 normothermic CPB (rectal temperature > 36 degrees C; n = 15). MEASUREMENTS AND MAIN RESULTS: Plasma levels of circulating (soluble) adhesion molecules (endothelial leukocyte adhesion molecules [sELAM-1], vascular cell adhesion molecule-1 [sVCAM-1], intercellular adhesion molecule-1 [sICAM-1], and granule membrane protein 140 [sGMP-140]) were measured from arterial blood samples using enzyme-linked immunosorbent assays (ELISA) after induction of anesthesia (= baseline values), after weaning from bypass, at the end of surgery, 5 hours after the end of CPB, and on the morning of the first postoperative day. Mean rectal temperature of group 1 was 27.2 +/- 0.4 degrees C and 36.7 +/- 0.4 degrees C in group 2. In both groups, plasma levels of sELAM-1 were significantly higher than baseline only 5 hours after CPB. sICAM-1 increased until the first postoperative day (group 1: +35%; group 2: +37%) without, however, exceeding the normal range. sVCAM-1 plasma levels increased after CPB (group 1: +56%; group 2: +40%). At the end of surgery and 5 hours after CPB, sGMP-140 plasma levels were significantly higher in the hypothermic (increase from 301 +/- 34 to 582 +/- 57 ng/mL) than in the normothermic patients (increase from 310 +/- 45 to 480 +/- 32 ng/mL). On the first postoperative day, both groups showed similar, significantly elevated plasma levels of sGMP-140. CONCLUSIONS: Plasma levels of circulating adhesion molecules sELAM-1, sICAM-1, and sVCAM-1 did not differ between hypothermic and normothermic CPB, indicating no differences in endothelial activation between the two groups. Only sGMP-140 plasma levels were increased more after hypothermic CPB. Additional influences of hypothermia on the coagulation system might have contributed to the higher sGMP-140 plasma levels of these patients. The definite role of circulating adhesion molecules in cardiac surgery patients remains to be elucidated.

Influence of intravenous administration of angiotensin-converting enzyme inhibitor enalaprilat on cardiovascular mediators in cardiac surgery patients.

The renin-angiotensin system (RAS) is important in controlling and maintaining cardiovascular homeostasis. In a randomized, prospective study, the response to intravenous (i.v.) administration of the angiotensin-converting enzyme (ACE) inhibitor enalaprilat (0.06 mg/kg) on important controllers of the circulation was investigated in 14 patients undergoing aortocoronary bypass grafting with a mean arterial blood pressure (MAP) > 85 mm Hg after induction of anesthesia. Fourteen patients received saline solution as placebo (control group). Endothelin (ET), atrial natriuretic peptide (ANP), catecholamine (epinephrine, norepinephrine) plasma levels, and ACE activity were measured from arterial blood sampled before injection of enalaprilat or NaCl solution (baseline values), 10 min and 30 min thereafter, immediately before the start of cardiopulmonary bypass (CPB), immediately after CPB, and at the end of surgery. MAP, heart rate (HR), cardiac index (CI), and systemic vascular resistance (SVR) were also monitored. ACE activity was similar at baseline in both groups; after i.v. injection of enalaprilat, it significantly decreased (from 35.1 +/- 11 to 4.4 +/- 1.0 U.min-1.L-1 30 min after injection) and remained reduced until the end of the operation (295 +/- 31 min after injection). ANP plasma levels were increased beyond normal (> 100 pg/mL) at baseline in both groups. They increased significantly in the control patients, but remained almost unchanged in the enalaprilat-treated patients within the entire study period. Plasma concentration of ET also increased only in the control group and was increased after CPB (8.6 +/- 1.2 pg/mL at the end of the operation).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiorespiratory response of intravenous angiotensin-converting enzyme inhibitor enalaprilat in hypertensive cardiac surgery patients.

Twenty-four patients undergoing elective coronary artery bypass surgery were studied. Either the angiotensin-converting enzyme (ACE) inhibitor enalaprilat, 0.06 mg/kg, (n = 12), or saline solution (= control group; n = 12), was randomly and blindly administered intravenously when the mean arterial blood pressure (MAP) increased to 90 mmHg after induction of anesthesia. Cardiorespiratory parameters were studied before injection, during the subsequent 30 minutes, precardiopulmonary bypass (CPB), post-CPB, and at the end of surgery. MAP was significantly reduced 5 minutes after administration of enalaprilat. The peak reduction of blood pressure was observed after 30 minutes (from 98 +/- 4 to 68 +/- 8 mmHg). Even immediately before CPB (112 +/- 12 minutes after injection of enalaprilat), MAP and systemic vascular resistance were significantly lower than baseline values. Heart rate remained almost unchanged in both groups. Cardiac index increased slightly in the enalaprilat patients (maximum: +0.75 L/min/m2 20 minutes after injection). Filling pressures (central venous pressure, pulmonary capillary wedge pressure) were also significantly reduced by enalaprilat. There were no differences from the control patients with regard to changes in right ventricular hemodynamics (right ventricular ejection fraction, right ventricular end-diastolic volume, right ventricular end-systolic volume), pulmonary gas exchange (PaO2), or intrapulmonary right-to-left shunting (Qs/Qt). VO2 increased only in the enalaprilat patients (from 179 +/- 28 to 230 +/- 30 mL/min) (p < 0.05). Cardiorespiratory parameters did not differ between the two groups post-CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Absence of xanthine oxidoreductase activity in human myocardium.

STUDY OBJECTIVE: The aim was to examine whether or not xanthine oxidase activity may be a significant source of oxygen derived free radicals in the human heart. DESIGN: Xanthine oxidoreductase activity of human myocardium was assayed in vitro. In addition, tests were performed to assess whether or not endogenous inhibitors of the enzyme were present in myocardial homogenates. The enzyme assay was based on high performance liquid chromatography with electrochemical and/or radiochemical detection of hypoxanthine, xanthine, and urate. SUBJECTS: Measurements were done on (a) isolated perfused rat myocardia and (b) left ventricular needle biopsies and papillary muscles obtained during elective cardiac surgery (chiefly aortic and/or mitral valve replacement and aortocoronary bypass) (n = 105 patients). MEASUREMENTS AND MAIN RESULTS: Homogenisation of human papillary muscles in buffer caused significant accumulation of hypoxanthine but not xanthine or urate. In addition, during incubation of crude myocardial homogenates with exogenous xanthine or hypoxanthine in the presence of NAD+ and/or O2 no production of urate was detected. Likewise, following aerobic incubation of papillary muscle homogenates with 14C-hypoxanthine neither 14C-xanthine nor 14C-urate were formed. Absence of xanthine oxidising activity was also observed with human papillary muscle extracts that were subjected to either ultrafiltration or gel filtration. In contrast, the rat heart was found to contain abundant xanthine oxidoreductase activity. The rat heart enzyme was inhibited by both allopurinol and oxypurinol but remained active when mixed with human papillary muscle homogenates. CONCLUSIONS: These findings show absence of xanthine oxidase and xanthine dehydrogenase activities in human myocardium, indicating that xanthine oxidase is not a source of oxygen derived free radicals in the human heart.

Factors determining ventricular fibrillation after induced cardiac arrest.

Ventricular fibrillation following release of the aortic cross clamp is not uncommon. In 38 patients undergoing aortic valve replacement we investigated if this disturbance of rhythm is due to perioperative myocardial ischemia or due to deterioration of myocardial function prior to surgery. In all cases hypothermic cardioplegic arrest (Bretschneider) was used. The mean duration of ischemia was 49.39 +/- 10.46 minutes. After release of the aortic cross clamp in 17 of 38 patients ventricular fibrillation occurred. To find out which factors are responsible for the occurrence of ventricular fibrillation we performed a statistical analysis. Thereby we found out that the occurrence of ventricular fibrillation did not correlate with ischemia, the maximal level of myocardium-bound creatine kinase, the NYHA stage, or the left ventricular end diastolic pressure. The left-ventricular concentration of noradrenaline determined just before release of the aortic cross clamp showed a significant negative correlation with the occurrence of ventricular fibrillation. From our results we conclude that ischemic injury was not the determining factor for the occurrence of ventricular fibrillation in our study. We suggest that the significant correlation with reduced myocardial noradrenaline content demonstrates that myocardial deterioration prior to surgery is the determining factor for the occurrence of ventricular fibrillation.

A newly designed venous cannula for use during total cardiac bypass in the closed chest by femoro-femoral perfusion.

A two-staged venous cannula was developed for total cardiac bypass in the closed chest during femoro-femoral perfusion. This was as effective as the dual cannula system. Its use is advocated in repeat open heart surgery.

[Effect of the duration of reperfusion on metabolic recovery during unloading of the hypertrophic heart following induced heart arrest]. / Einfluss der Reperfusionsdauer auf die metabolische Erholung während Entlastung des hypertrophen Herzens nach induziertem Herzstillstand.

The methods of cardioplegia used today are not always able to sufficiently protect the hypertrophied heart. The present study investigated if a recovery period of 30 min before the end of ECC improves metabolic recovery of the heart in comparison to a recovery period of 15 min before terminating extracorporeal circulation. A clinical study was performed of patients undergoing aortic valve replacement. In one group reperfusion was performed for 15 min and in the second group for 30 min before the conclusion of extracorporeal circulation. The concentration of high energy phosphates in the left ventricle was determined at the end of the ischemic period, after 15 min and after 30 min of reperfusion. The behavior of the myocardial metabolites of the two groups showed no differences. Creatinephosphate increased continuously in both groups, while adenosine triphosphate and the adenonucleotide pool did not change during the reperfusion period. From our results we conclude that under the conditions given in our study a recovery period of 15 min is sufficient for metabolic recovery and prolongation of reperfusion before termination of extracorporeal circulation do not improve metabolic recovery.

[Combined therapy of re-coarctation of the aorta and coronary heart disease].

We report on an uncommon case of recoarctation of the aorta 36 years after resection and end-to-end anastomosis associated with coronary heart disease. Since a two-staged surgical therapy implies an increased risk of life for the patient, we decided to perform a combined surgical procedure. Exposing the heart by a median sternotomy we implanted a 16 mm synthetic graft from the ascending to the descending thoracic aorta and performed a prosthesis-coronary bypass in one session. The patient had an uneventful recovery. In our opinion this procedure is the method of choice for similar cases.

Primary cardiac tumors--clinical experiences and late results in 48 patients.

Between 1971 and 1987 48 patients (35 female and 13 male) underwent operations at the Department of Cardiovascular Surgery, Justus-Liebig-University Giessen, for primary cardiac tumors. The age of the patients ranged from 21 to 71 years. Clinical symptoms were congestive heart failure, cardiac murmurs and findings similar to mitral stenosis, chest pain, arrhythmias, arterial embolism, myocardial infarction and pericarditis. 39 of the tumors were benign and 9 were malignant. Diagnosis was confirmed by echocardiography and/or cineangiocardiography. The left atrium was most commonly involved, followed by the right atrium. Surgery was performed in all cases using cardiopulmonary bypass. Benign tumors were totally removed, including attachment to the atrial septum or the free wall. In one case the tumor resection was carried out by autotransplantation of the heart. During the perioperative period we lost one of the 39 patients with benign tumors due to low cardiac output. Observing a mean follow up period of 48 months, no recurrence of tumors was noted and all patients are doing well now. The malignant neoplasms could not be removed completely, and in 4 cases only a reduction of the tumor mass was possible. Three of the 9 patients died during the postoperative period. Only one patient survived longer than 48 months. Whereas surgical therapy of malignant cardiac tumors is still a matter of discussion based upon these discouraging results, benign or semimalignant cardiac neoplasms have a very favourable prognosis when the surgical intervention can be performed prior to the occurrence of severe complications, such as congestive heart failure and arterial embolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic arch replacement by posterolateral exposure.

Aortic arch replacement was carried out in a 54 year old male patient with an unexpected type A-dissection, using partial femoro-femoral bypass and hypothermic arrest, through a left side posterolateral thoracotomy. After the replacement of the aortic arch from the ascending to the descending aorta a warm-up perfusion was done through an 8 mm side arm Dacron prosthesis attached to the descending segment of the 30 mm Dacron graft. This technique was demonstrated to be safe and protective in our patient and can be used as an alternative surgical method in the treatment of aortic arch dissection or aneurysms of the transverse aortic arch.