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At least 235 records · Page 13Linked to original sources
PubMed1985

Extracorporeal circulation with deep hypothermia and circulatory arrest in the treatment of intracranial arterial aneurysms.

Extracorporeal circulation with circulatory arrest and deep hypothermia in surgery on certain giant intracranial arterial aneurysms or on aneurysms difficult to access is described. The series includes a giant left carotid aneurysm, an aneurysm of the basilar artery bifurcation, a patient with two aneurysms, one on the right middle cerebral artery and the other at the end of the basilar artery, and a fourth patient with two aneurysms, one on the right middle cerebral and the other on the right carotid. Closed-thorax extracorporeal circulation with femoral cannulation was performed on all the patients. Surgical procedure is described and the advantages and disadvantages discussed. Results are encouraging. The authors suggest that the technique be used during surgical treatment of certain intracranial aneurysms that are in awkward positions or are very large in size. They emphasize that the procedure should be confined to exceptional cases.

Adult↗
PubMed1998

[Two cases of clipping surgery of cerebral aneurysm under profound hypothermia with closed-chest extracorporeal circulation].

A 68-year-old female and a 47-year-old male patients underwent clipping surgery for giant basilar arterial and thrombotic internal carotid arterial aneurysms respectively with closed-chest extracorporeal circulation (femoro-femoral bypass). Profound hypothermia and continuous infusion of thiamylal were used to prevent brain damage. Blood outflow via the femoral vein was sufficient to induce profound hypothermia down to 20 degrees C. Hemodynamics were controllable without catecholamines during closed-chest extracorporeal circulation. Preoperative symptoms significantly improved and no neurological complication was observed in either case postoperatively. Right femoral phlebothrombosis was, however, observed in one case. In conclusion, profound hypothermia with closed-chest extracorporeal circulation is a safe technique to reduce the complications induced by open-chest technique, but special attention should be given to postoperative phlebothrombosis.

Aged↗
PubMed1979

Plasma administration to defibrinogenated dogs during extracorporeal circulation.

Plasma, in an amount corresponding to 0.05 gm fibrinogen/Kg of body weight, was administered during one hour to defibrinogenated dogs subjected to extracorporeal circulation. Four blood filters included in the extracorporeal circuit were removed one by one at 30-minute intervals. The prefilter pressures rose gradually during the whole experiment. Scanning electron microscopy of the filter surface revealed equal amounts of deposits before, during and after the infusion of plasma. Only minimal amounts of fibrin were found on the filter surfaces by immunoelectrophoresis. Mean arterial pressure, arterial blood gases, fibrinogen concentration, platelet count and leukocyte count were followed before, during and after plasma infusion and showed no significant changes. Thus, it is possible to administer limited amounts of plasma to defibrinogenated dogs subjected to extracorporeal circulation.

Animals↗
PubMed1994

[Severe bronchospasm induced by extracorporeal circulation for cardiac surgery].

Cardiac surgery was performed on a 50-yr-old man suffering from mitral valve stenosis. He has no history of allergic disease or bronchial asthma. Mitral valve was replaced uneventfully under extracorporeal circulation, and ventilation with pure oxygen was tried. But the lung was so stiff that the bag of anesthetic circuit could not be squeezed by hand. Fiberoptic bronchoscopy revealed no obstruction in endotracheal tube or bronchial tree. A presumptive diagnosis of severe bronchospasm was made, and partial extracorporeal circulation was maintained. Soon after aggressive bronchodilator therapy, there was noticeable improvement in pulmonary compliance, and the patient was removed from bypass uneventfully. No further recurrence of bronchospasm was seen in the intra- or postoperative period. Although the exact causes for bronchospasm in our case are not clear, we concluded that severe bronchospasm was induced by extracorporeal circulation. Possible etiologies and the management of patients with this problem are reviewed.

Adult↗
PubMed1981

Intra-ocular pressure before, during and after extracorporeal circulation in pigs.

Variations in intra-ocular pressure (IOP) were demonstrated before, during and after extracorporeal circulation in pigs. Most probably both the observed increase and reduction in IOP may be explained by corresponding changes in blood osmolality, blood pressure and body temperature. In contrast to clinical findings, no increase in IOP was observed during the period of extracorporeal circulation.

Animals↗
PubMed1998

In vitro anticoagulant properties of a minimum functional fragment of human thrombomodulin and in vivo demonstration of its benefit as an anticoagulant in extracorporeal circulation using a monkey model.

Recently, we demonstrated that the last three consecutive epidermal growth factor-like structures of human thrombomodulin form the minimum functional fragment for protein C activating activity. In this study, the recombinant minimum functional fragment of human thrombomodulin (E456) had similar activities for protein C activation and clotting time compared to the recombinant extracellular domains of human thrombomodulin (rhsTM) previously described. E456 had a shorter half-life (6-9 min) in animals, compared to rhsTM (5 h). To evaluate whether or not E456 is a suitable anticoagulant for extracorporeal circulation, the effects of E456 were investigated in the extracorporeal circulation model in monkeys. The effect of E456 at a dose of 0.03 mg/kg plus 0.113 mg/kg/h on circuit pressure was as potent as that of low molecular weight heparin, Fragmin, at a dose of 30 IU/kg plus 15 IU/kg/h. E456, however, also more effectively suppressed an increase of thrombin-antithrombin III complex than Fragmin. Also the APTT quickly returned to the pre-treatment level following E456, but did not when using Fragmin. Moreover, E456 had no influence on the plasma free fatty acid levels, while Fragmin significantly increased them. Thus, E456 appears to have anticoagulant properties which make it more suitable anticoagulant in extracorporeal circulation than Fragmin.

Animals↗
PubMed1991

[Postponed closure of the sternum after operations on the heart with extracorporeal circulation].

Data on postponed closure of the sternum in 3 patients who were operated on with extracorporeal circulation are discussed. Various clinical and technical aspects of the applied method are considered. On the basis of their personal experience and the literature data, the authors discuss the causes of the development of acute heart dilatation in operations with extracorporeal circulation and, with due regard for this, substantiate the indications for the use of the method. Postponed closure of the sternum is a promising method of treatment of critical hemodynamic disorders which occur at the stage of closure of the sternotomy and are characterized by the picture of cardiac tamponade.

Cardiac Tamponade↗
PubMed2004

[Endothelial parameters in blood plasma of patients suffering from ischaemic heart disease and undergoing surgery with extracorporeal circulation].

INTRODUCTION: The participation of disturbances of the vascular endothelial function in the pathogenesis of post perfusion syndrome is controversial. AIM: The aim of the study was the evaluation of the parameters of vascular endothelial injury in the blood plasma of patients undergoing surgery with extracorporeal circulation. METHODS: The study was performed in the group of 32 patients (M/F 23/9) with ischaemic heart disease, undergoing coronary artery bypass with extracorporeal circulation. In the blood plasma obtained in the couple of time points in the perioperative period the determinations were done as followed: the concentrations of von Willebrand factor antigen (vWf Ag), tissue plasminogen activator antigen (t-PA Ag), antigen of plasminogen activator inhibitor type 1 (PAI-1 Ag) and fibrinogen. The control group consisted of 29 healthy volunteers sex and age matched. RESULTS: In blood of patients suffering from ischaemic heart disease before surgery the increased concentrations of vWF Ag, t-PA Ag and fibrinogen were observed. The concentrations of t-PA Ag and vWf Ag hesitated in the perioperative period but always were significantly higher than observed in the control group. CONCLUSIONS: (1) In the blood of patients suffering from the ischemic heart disease undergoing bypass surgery with an extracorporeal circulation the increased concentrations of t-PA Ag and vWf Ag were observed what is the evidence of stimulation/ damage of the vascular endothelium. (2) High levels of t-PA and vWf is seemed to be connected with injury of vessels during coronary artery bypass.

Adult↗
PubMed1991

Effects of simulated extracorporeal circulation on human leukocyte elastase release, superoxide generation, and procoagulant activity.

Activated leukocytes are thought to contribute to respiratory dysfunction, alterations in microvascular permeability, disseminated intravascular coagulation, and thrombosis, all of which can complicate extracorporeal circulation. The purpose of this work was to determine the effects of extracorporeal circulation on leukocyte functions likely to mediate organ damage. White blood cell counts in the bubble circuits (n = 5) fell to 51% +/- 7% (mean +/- standard error of the mean; p less than 0.05) of initial levels within 2 hours of recirculation. In contrast, counts from both the spiral coil (n = 5) and hollow-fiber (n = 5) groups remained at 91% +/- 12% and 100%, respectively. Plasma levels of human neutrophil elastase rose from 0.28 +/- 0.06 micrograms/ml to 3.14 +/- 0.36 micrograms/ml (p less than 0.05) and 0.20 +/- 0.02 micrograms/ml to 1.61 +/- 0.35 micrograms/ml (p less than 0.05) in bubble and spiral coil circuits, respectively, but from only 0.20 +/- 0.03 micrograms/ml to 0.96 +/- 0.42 micrograms/ml in the hollow-fiber circuit despite 2 hours of recirculation. Consistently, in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine, a chemotactic peptide, cells from spiral coil and bubble circuits released and generated significantly less elastase and superoxide anion, respectively. In contrast, neutrophils from the hollow-fiber circuits demonstrated enhancement of N-formyl-L-methionyl-L-leucyl-L-phenylalanine-induced elastase release and superoxide generation. Finally, mixed leukocytes from all circuits expressed procoagulant activity reaching statistical significance in bubble circuits. In conclusion, extracorporeal circulation has pronounced effects on neutrophil elastase release, superoxide anion generation, and leukocyte procoagulant activity. Spiral coil and bubble oxygenators cause granule release and, subsequently, reduced sensitivity to soluble agonists. In contrast, hollow-fiber oxygenators "prime" cells, actually enhancing reactivity. Recirculation through all circuits induces leukocyte procoagulant activity that is likely to contribute to surface-induced thromboses and excessive bleeding.

Blood Coagulation↗
PubMed1982

[Water-electrolyte and acid-base changes during extracorporeal circulation].

Changes in fluid, electrolyte and acid-base balance were evaluated in 8 patients during extracorporeal circulation. H2O increase and osmolarity and colloid osmotic pressure decrease, due to priming and perfusion technique used for cardiopulmonary by pass, were found. Mild respiratory alkalosis was also present. K+ serum, because of KCL supplements, was always maintained within the normal values, while Na+ serum concentration was low, despite of large amounts of Na+ infused during perfusion. After examination of disturbances in fluid, electrolyte and acid-base balance, the Authors report the performed corrections and emphasize the importance of a prompt recognition and the immediate therapy of these changes to avert serious cardiac impairments during extracorporeal circulation or during the immediate postoperative period.

Acid-Base Equilibrium↗
PubMed2001

Leukodepletion and aprotinin improve clinical outcome after extracorporeal circulation.

Most cardiac operations involve the use of extracorporeal circulation with its attendant systemic inflammatory response syndrome. Many anti-inflammatory strategies hold promise for reducing the associated morbidity of cardiopulmonary bypass. The application of pharmacological and mechanical strategies to control this inflammatory response now has demonstrable clinical benefit. The additional costs of these successful strategies are offset by the economic savings and improved quality of care.

Adrenal Cortex Hormones↗
PubMed1982

Release of lysosomal hydrolases during simulated extracorporeal circulation.

Contact with surfaces results in activation of formed blood elements. This study demonstrates that during extracorporeal circulation, release of lysosomal enzymes occurs concomitantly with platelet granule secretion. Fresh, heparinized human blood was recirculated for 2 hours at 1,000 ml/min at 37 degrees C in silicone rubber circuits containing a membrane oxygenator (0.85 m2). The plasma levels of a platelet-specific protein, low affinity platelet factor 4 (LA-PF4), rose from less than 0.5 to 16 +/- 3 SEM microgram/ml plasma, indicating extensive release of platelet alpha granule contents. Concurrently, plasma activity of acid phosphatase and N-acetyl-beta-glucosaminidase increased nearly fivefold. Platelet inhibition prevented release of LA-PF4 and reduced acid phosphatase levels, but failed to alter the levels of N-acetyl-beta-glucosaminidase. Lidocaine (10 to 20 microgram/ml), however, prevented the rise in N-acetyl-beta-glucosaminidase activity and diminished acid phosphatase levels without altering secretion of LA-PF4. The failure of platelet inhibitors to block the increase in N-acetyl-beta-glucosaminidase, and the efficacy of lidocaine to do so without altering LA-PF4 secretion, suggest that leukocytes, not platelets, are the primary source of this lysosomal enzyme. Although acid phosphatase activity measured in plasma my be derived from leukocytes, platelet membranes, and not lysosomes, appear to be a more likely source. Release of hydrolytic enzymes from formed blood elements during cardiopulmonary bypass may cause endothelial cell injury and thus contribute to the increased vascular permeability associated with extracorporeal circulation.

Acetylglucosaminidase↗
PubMed1983

[Heparin level determination during extracorporeal circulation in open heart surgery].

Because of the high dosages which have to be given during extracorporal circulation it is often impossible to measure the end point of coagulation for both thrombin time and aPTT. A correct determination of the heparin level has become possible with synthetic substrates with the help of the "Protopath proteolytic enzyme detection system" (AHS, Munich). With a fluorogenic synthetic substrate in a one-way cuvette and calibrated fluorometer the heparin and AT III levels can easily be measured. Very high levels of heparin which averaged 6,9 U/ml +/- 1,0 10 minutes after heparinization and 4,4 U/ml +/- 1,0 60 minutes later were found in ten patients with open heart surgery during extracorporal circulation. AT III decreased to less than 50% possibly due to dilutional effects. Ten minutes after protamine neutralization heparin levels were less than 0,1 U/ml. After two hours AT III levels returned to 70%. Measurement of heparin blood levels adds to the quality of anticoagulant control in situations where high dosages of heparin are given.

Adult↗
PubMed1990

Cerebral dysfunction following extracorporeal circulation for aortocoronary bypass surgery: no differences in neuropsychological outcome after pulsatile versus nonpulsatile flow.

Nonpulsatile perfusion techniques with extracorporeal circulation for open-heart surgery and aortocoronary bypass grafting are widely used; this treatment is often followed by temporary or permanent neurological deficits. Experimental studies suggest that pulsatile flow may be of greater benefit because of its ability to ameliorate cerebral microcirculation. We therefore investigated 22 men who underwent aortocoronary bypass grafting. Patients were randomly divided into either a group undergoing nonpulsatile (n = 14) or pulsatile flow (n = 8). Neurological examinations were done prior to the operation and on the 7th postoperative day. EEG, cerebral blood flow (CBF), and the metabolic rates of O2 (CMR O2) and glucose (CMR Glucose) were measured before anaesthesia and 30 minutes after the start of extracorporeal circulation, when venous blood temperature was 26 degrees C. Postoperative neurological symptoms consisted of cranial nerve palsies, dysfunctions of the visual cortex, cerebellar symptoms, and slight arm paresis, but no differences between the two treatment groups were detected. Moreover, changes in EEG, CBF, and CMR rates during anaesthesia did not differ between the two groups. Our data suggest that pulsatile flow is not superior to the nonpulsatile perfusion technique, but to confirm this larger patient samples are required.

Adult↗
PubMed2007

Leukocyte effects of C5a-receptor blockade during simulated extracorporeal circulation.

BACKGROUND: Distinct pathways of leukocyte activation during simulated cardiopulmonary bypass are mediated by the complement C5a anaphylatoxin. We hypothesized that a human C5a receptor antagonist would specifically inhibit the inflammatory response of neutrophils to simulated extracorporeal circulation, while preserving the C5b-9 pathway for innate immunity. METHODS: An in vitro extracorporeal circuit recirculated fresh heparinized whole blood through a membrane oxygenator with and without addition of a small molecule human C5a receptor antagonist. Samples were periodically drawn over 90 minutes for complement and leukocyte activation studies. RESULTS: Addition of the C5a receptor antagonist to simulated extracorporeal circulation abrogated both neutrophil CD11b upregulation and interleukin 8 release (p < 0.01 for both), despite full generation of C3a and C5b-9; however, elastase release from neutrophils was unaffected. Although C5a receptor blockade only trended toward inhibiting monocyte CD11b upregulation (p = 0.09), circuit clearance of both monocytes (p = 0.04) and neutrophils (p = 0.01) was significantly decreased. In addition, the C5a receptor antagonist completely blocked both neutrophil-platelet and monocyte-platelet conjugate formation (p < 0.001 for both), without affecting platelet P-selectin expression. CONCLUSIONS: C5a receptor blockade during simulated extracorporeal circulation completely blocked neutrophil beta2 integrin upregulation and induction of plasma interleukin 8, suggesting an acute downregulatory effect on neutrophil chemotaxis-related pathways, while preserving terminal complement generation and neutrophil elastase release. Inhibition of leukocyte-platelet conjugate formation suggests a novel function for leukocyte adhesive receptors, possibly related to preservation of elastase generation.

Blood Platelets↗
PubMed2000

Neuron-specific enolase increases in plasma during and immediately after extracorporeal circulation.

BACKGROUND: Minor cerebral complications are common after cardiac surgery. Several biochemical markers for brain injury are under research; one of these is neuron-specific enolase (NSE). The purpose of this study was to investigate the release of this enzyme into the blood during and immediately after extracorporeal circulation and to evaluate the effect of hemolysis on this release. METHODS: Sixteen patients scheduled for elective heart surgery were included in the study. Blood samples for analysis of NSE and free hemoglobin in plasma were drawn before, during, and up to 48 hours after the end of extracorporeal circulation. The release of NSE from erythrocytes and its correlation to the release of free hemoglobin was studied by serial dilution and hemolysis in vitro. RESULTS: The peri- and postoperative course was uneventful in all patients. Extracorporeal circulation initiated a release of NSE that reached a maximum 6 hours after the end of perfusion. Thereafter, the levels declined with an estimated t1/2 of 30 hours. The concentration of free hemoglobin increased during the perfusion, with maximum levels at the end of perfusion, after which they fell rapidly to normal values. The in vitro study showed a strong linearity between the release of NSE and free hemoglobin after induced hemolysis. CONCLUSIONS: The increased levels of enolase at the end of cardiopulmonary bypass can, to a major part, be explained by the release from hemolysed erythrocytes. The value of NSE as a marker for brain injury in these situations is therefore doubtful.

Adult↗
PubMed1980

[The effects of Akrinor on the extrathoracic capacitance vessels during extracorporeal circulation and on cardiac haemodynamics of anaesthetized man (author's transl)].

The circulatory effects of Akrinor were investigated in anaesthetized patients during extracorporeal circulation and following open heart surgery. Arterial pressure, cardiac index and the maximal rate of rise of left ventricular pressure increased, whereas the resistance to flow in both circuits and the cardiac filling pressures remained unchanged. The compliance of the extrathoracic capacitance vessels during extracorporeal circulation was unaltered compared with the control group, but the volume content was less after Akrinor (200 ml). If this volume is shifted to the intrathoracic compartment in the intact circulation, the amounts seems too small to explain the increase in cardiac index. This increase and the subsequent rise of the arterial pressure seemed to be due to increased myocardial contractility.

Anesthesia↗