Retraction notice to "Does correction of acidosis influence microcirculatory blood flow during cardiopulmonary bypass?" [Br J Anaesth 71 (1993) 277-81].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief, Professor Hugh Hemmings, based on the recommendations of Justus-Liebig-University Giessen following an internal review of research conducted by Joachim Boldt at the University. This is further described in 'Further Retractions of Articles by Joachim Boldt', https://doi.org/10.1016/j.bja.2020.02.024.

Retraction notice to "Influence of different anticoagulation regimens on platelet function during cardiac surgery" [Br J Anaesth 73 (1994) 639-44].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief, Professor Hugh Hemmings, based on the recommendations of Justus-Liebig-University Giessen following an internal review of research conducted by Joachim Boldt at the University. This is further described in 'Further Retractions of Articles by Joachim Boldt', https://doi.org/10.1016/j.bja.2020.02.024.

Retraction notice to "Endothelial-related coagulation in cardiac surgery" [Br J Anaesth 74 (1995) 174-9].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief, Professor Hugh Hemmings, based on the recommendations of Justus-Liebig-University Giessen following an internal review of research conducted by Joachim Boldt at the University. This is further described in 'Further Retractions of Articles by Joachim Boldt', https://doi.org/10.1016/j.bja.2020.02.024.

Dual chamber pacemaker implantation in dogs with atrioventricular block.

BACKGROUND: Pacemaker implantation is the treatment of choice for symptomatic bradyarrhythmias. In dogs, a single chamber system is commonly used. In human patients with high-grade 2nd- or 3rd-degree atrioventricular (AV) block, physiologic pacing is recommended, because it improves cardiac output, blood pressure, exercise tolerance, and quality of life. In dogs, this type of pacing is seldom used. HYPOTHESIS: The implantation of a dual chamber pacemaker in dogs with AV block is a feasible procedure for restoring AV synchrony. ANIMALS: Thirty-three privately owned dogs with high-grade 2nd- or 3rd-degree AV block were included. METHODS: Patient data of all dogs with AV block presented for pacemaker implantation between December 1997 and November 2004 were reviewed. RESULTS: Dual chamber pacemaker implantation with AV synchronous stimulation was successfully performed in 33/33 dogs (100%). In 9/33 (27%) major and in 12/33 (36%) minor complications were observed. Mean survival time for the patients discharged from hospital (n = 32) was 33.6 +/- 20.4 months (range, 3.9-83.5 months). CONCLUSION AND CLINICAL IMPORTANCE: Dual chamber pacing is a feasible procedure in dogs with 2nd- or 3rd-degree AV block and is not associated with a higher complication rate compared with single chamber pacemaker systems. A major advantage over ventricular demand pacemaker systems is the restoration of AV synchrony for a substantial period of time.

Circulating adhesion molecules in cardiac operations: influence of high-dose aprotinin.

Cardiac operations using cardiopulmonary bypass (CPB) are associated with a systemic inflammatory response most likely attributable to the release of various inflammatory mediators and activation of complement or coagulation cascade. In addition, (circulating) adhesion molecules, such as endothelial leukocyte adhesion molecule (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1), appear to be of central importance in the CPB-related inflammatory process. In this situation, antiproteases, such as aprotinin, may help to prevent damage of endothelial integrity. In a prospective study, 40 consecutive patients undergoing elective cardiac operation were randomly divided into two groups (with 20 patients in each group): in group 1 "high-dose" aprotinin was used (2 million IU of aprotinin before CPB, 500,000 IU/h until end of operation, 2 million IU added to the prime) (with aprotinin), and in group 2 no aprotinin was given (without aprotinin). Circulating adhesion molecules (cICAM-1, cELAM-1, and cVCAM-1) were measured from arterial blood samples using ELISA after induction of anesthesia (baseline), during CPB, at the end of the operation, 5 hours after CPB, and on the first postoperative day. The two groups were comparable concerning their biometric profile and CPB data. Baseline values of circulating adhesion molecules were within normal range and similar in both groups. During CPB, hemodilution resulted in a decrease in all circulating adhesion molecules. On the first postoperative day, cICAM-1 (with aprotinin, 215 +/- 32 ng/mL; without aprotinin, 230 +/- 40 ng/mL) and cELAM-1 (with aprotinin, 28 +/- 6 ng/mL; without aprotinin, 31 +/- 6 ng/mL) returned to baseline values.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulsatile flow pattern in cerebral arteries during cardiopulmonary bypass. An evaluation based on transcranial Doppler ultrasound.

Pulsatile wave patterns in basal cerebral arteries were studied by means of transcranial Doppler ultrasound (TCD) in 11 patients undergoing cardiopulmonary bypass (CPB) surgery. Different physiological states and technical parameters were demonstrated influencing wave forms delivered from a pulsatile CPB roller pump. The results gave evidence of the variability of pulsatile perfusion which may explain the inconsistency in the literature concerning its effectiveness in preserving tissue function. TCD proved to be a useful approach to define pulsatility of cerebral blood flow during CPB.

A modified technique for the production of an arterio-venous shunt in sheep, allowing a comparison of biocompatibility of synthetic materials.

Polytetrafluorethylene (PTFE) prostheses were implanted in 12 sheep as a shunt between the carotid artery and the jugular vein using an end-to-side anastomosis technique. This technique allows repeated tests of the pharmacological and toxicological safety of artificial kidney units after both single and multiple administration. Furthermore, it enables the investigation of detoxification of compounds via dialysis, thus contributing to drug safety. Implantation of the prosthesis was uncomplicated. Connection to the extracorporeal circulation was achieved via catheters and maintained using a pump with an output of up to 300 ml/min. This enabled maintenance of extracorporeal circulation for several hours without clinical impairment to the animals. The AV-shunts remained functional for between 8 and 253 days (mean 112.3 days).

Impact of pretransplant intravenous immunoglobulin administration on anti-AB0 antibody levels in AB0-incompatible living donor kidney transplantation.

BACKGROUND: From March 2007 to July 2010, we performed 14 AB0-incompatible (AB0i) living kidney transplantations using donor blood group-specific immunoadsorption (IA), anti-CD20 monoclonal antibody, and intravenous immunoglobulin (IVIG) pretreatment. METHODS: To analyze the effect of a presumed anti-donor blood group-specific antibody transfer by IVIG administration (0.5 g/kg; 5.4 ± 0.9 days pretransplant), we assessed AB0i antibody titers in different IVIG preparations and evaluated their impact on patient AB0i antibody titers. RESULTS: AB0i antibody IgG titers before treatment ranged from 8 to 1024. We performed 6.9 ± 1.1 IA procedures pretransplant to reach AB0i antibody titers ≤4, which enabled successful transplantation in all pretreated patients. Their mean serum creatinine at discharge was 1.5 ± 0.1 mg/dL. IVIG preparations differed profoundly in their AB0i antibody titers: The lowest titers were observed in Sandoglobulin preparations (1-8) compared with Intratect (2-128), Octagam (4-32) and Gamunex (2-512). Usually, administration of the IVIG preparation containing the lowest isoagglutinin titer resulted in low AB0i antibody titer increments in patient sera: Sandoglobulin, 2 titer steps (n = 2), 1 titer step (n = 1), and 0 titer steps (n = 5). In contrast, Octagam showed 0 titer steps (n = 2) and Intratect, 0 titer steps (n = 3). However, after Gamunex administration, the AB0i antibody titer of 8 and the AB0i antibody titer rose 3 titer steps (16 to 128; n = 1), which could not be explained by passive transfer of isoagglutinin alone. CONCLUSION: Our data showed that the choice of IVIG preparation with the lowest AB0i antibody levels is a time- and cost-sparing step in the pretreatment of AB0i living donor kidney recipients. Posttransplant, a high isoagglutinin content within the IVIG preparation has the potential to induce antibody-mediated rejection.

Postoperative bleeding after AB0-incompatible living donor kidney transplantation.

BACKGROUND: Since 2007, we have performed 14 AB0-incompatible (AB0i) living kidney transplantations to increase the number of living kidney transplantations. METHODS: To prevent clotting, donor kidneys were perfused with an HTK/heparin solution with heparin washed out immediately pretransplantation. However, in 4/14 recipients, significant postoperative diffuse hemorrhage occurred with the need for surgical intervention in 3 patients. To analyze the cause of postoperative diffuse bleeding, sequentially before and after opening the graft anastomosis, we prospectively performed coagulation studies: partial thromboplastin time (PTT), thrombin time, thromboplastin time, fibrinogen, antithrombin, D-dimers, plasminogen, and thrombelastography. RESULTS: We found no clotting disturbances owing to blood group-specific immunoadsorption. However, 3/4 patients with bleeding complications showed elevated PTT values even 2 hours after opening the anastomosis, which was proven to be a heparin effect by in vitro application of heparinase. Hyperfibrinolysis and disturbances of platelet aggregation were not detected. Because of these results, we lowered the heparin dose administered after donor nephrectomy from initially 10,000-20,000 to 4000 IU resulting in significantly lower PTT values at 2 hours (34.6 ± 4.5 s among patients 6-14 vs 69.0 ± 16.3 s among patients 1-5; P = .012). There were no further bleeding complications. Lowering the heparin dosage had no impact on graft function: serum creatinine at discharge of 1.5 ± 0.1 versus 1.6 ± 0.2 mg/dL. CONCLUSION: Our data indicated that postoperative hemorrhage after AB0i kidney transplantation was associated with the amount of heparin used for graft perfusion after donor nephrectomy. The use of antifibrinolytic agents may be harmful; no hyperfibrinolysis takes place in the AB0i transplant setting.

Post-mortem evaluation of 415 pacemakers: in situ measurements and bench tests.

AIM: The hypothesis was that there is more undetected dysfunction of implanted pacemaker systems than that detected and corrected. This prompted a research project (sponsored by the German Research Foundation) to detect pacemaker abnormalities and evaluate their complications for patients, thus, proving or disproving the hypothesis. METHODS AND RESULTS: Four hundred and fifteen pacemakers of deceased patients were analyzed assessing their functionality by in situ measurements and bench tests including five measurements and one telemetric interrogation. Results were divided into four categories and statistically evaluated. Life-threatening abnormalities were found in 3.8%, potentially life-threatening in 3.7%, probably symptomatic, divided into atrial and ventricular problems, 13.3% and 2.8%, respectively, and premature exhaustion in 1.2%. Three of 179 bipolar ventricular leads and 2 of 131 bipolar atrial leads had insulation defects corresponding to 1.7% and 1.5%, respectively. The bipolar complication rate was 2.8 times higher than unipolar. CONCLUSION: The pacemaker patients investigated, living 4 years with their pacemaker on average, had a post-mortem evaluated complication rate of the category "life-threatening" of 3.8%. This result corresponds to an annual complication rate of 0.94% compared with a rate of only 0.39% in an earlier investigation.

[Constrictive pericarditis--surgery with or without heart-lung machine?]. / Die Perikarditis konstriktiva--Operation mit oder ohne Herz-Lungen-Maschine?

In patients suffering from constrictive pericarditis, the best hemodynamic results can be achieved by total mobilization of the heart and complete resection of the pericardium. Among 72 patients operated upon from 1969 to 1991, the use of extracorporeal circulation became necessary only twice. Therefore, we suggest the use of heart lung machine only in patients with bad myocardial function or in patients who need correction of additional diseases. Routine use of extracorporeal circulation is not mandatory.

Endothelial-related coagulation in cardiac surgery.

The endothelium appears to play an important role in the regulation of intravascular coagulation. Thrombomodulin is one of the anticoagulant substances that is expressed by endothelial cells. The influence of age and illness on the thrombomodulin-protein C system was studied prospectively in 80 cardiac surgery patients. Patients > 70 yr old (n = 20) were compared with patients < 50 yr (n = 20) (group I), and patients undergoing a simple cardiac procedure (n = 20) were compared with patients scheduled for complex surgery (n = 20) (group II). Thrombomodulin (normal < 40 ng ml-1), protein C and (free) protein S plasma concentrations were measured by enzyme-linked immunosorbent assays (ELISA) after induction of anaesthesia (baseline values), during and after cardiopulmonary bypass (CPB), at the end of surgery, 5 h after CPB and on the first day after operation. Blood loss and use of homologous blood and blood products were significantly greater in patients > 70 yr and in those undergoing complex surgery. At baseline, thrombomodulin concentration was increased in patients undergoing complex surgery (mean 52 (sd 9) ng ml-1). After bypass and after operation, thrombomodulin increased most in patients > 70 yr (from 40 (8) to 78 (10) ng ml-1) and in those patients who underwent complex cardiac operations (from 52 (8) to 79 (10 ng ml-1) (P < 0.05). Changes in protein C and protein S concentrations were similar in all groups. On the first day after operation only, protein C concentrations were reduced in patients > 70 yr and in patients who underwent complex cardiac surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrovascular carbon dioxide reactivity in carotid artery disease. Relation to intraoperative cerebral monitoring results in 100 carotid endarterectomies.

BACKGROUND: In patients with carotid artery disease, poor intracerebral collateralization is reflected by impaired cerebrovascular reactivity to carbon dioxide inhalation, which will improve after endarterectomy. The relationship between preoperative reactivity to carbon dioxide using transcranial Doppler sonography (TCD) and intraoperative changes of somatosensory evoked potentials (SEP) and TCD parameters were investigated. METHODS: In 94 patients, preoperative carbon dioxide reactivity was examined and defined impaired if mean blood flow velocity in the middle cerebral artery (Vm-MCA) increased less than 1.5% mmHg during carbon dioxide challenge. Patients then underwent 100 carotid operations under general anesthesia with both SEP and TCD monitoring. Shunts were placed if SEP amplitude decreased to less then 50% of control or central conduction time increased by 20% after clamping (critical SEP changes). TCD changes were defined as critical in case of a postclamping/preclamping Vm-MCA ratio < or = 0.4. The incidence of critical SEP and TCD changes was compared to preoperative carbon dioxide testing using Fisher's exact test with P < 0.05 considered significant. Postoperatively, neurologic state and carbon dioxide responsiveness were re-examined. RESULTS: Twelve patients showed impaired preoperative carbon dioxide reactivity on the side of operation, which improved markedly after surgery. The incidence of critical SEP changes in these cases (8.3%) was not significantly different from that in the remaining patients (14.8%). Critical SEP changes were significantly correlated with critical TCD changes (P < 0.0001). CONCLUSIONS: Patients with poor carbon dioxide reactivity (preoperative TCD testing) did not have an increased risk of cerebral ischemia during carotid surgery, as assessed by intraoperative SEP recording.

Circulatory effects of the PDE-inhibitors piroximone and enoximone.

1. The isolated circulatory response to intravenous application of the phosphodiesterase (PDE) inhibitors piroximone and enoximone was studied. 2. In a randomized sequence of 30 male patients undergoing elective aortocoronary bypass grafting either piroximone (0.5 mg kg(-1); n = 10) or enoximone (0.5 mg kg(-1); n = 10) were given during steady state of cardiopulmonary bypass (CPB). A group in which NaCl was given as a placebo served as a control (n = 10). 3. MAP was reduced by piroximone (maximum -23 mm Hg) and enoximone (maximum -18 mm Hg), whereas it increased in the control (+20 mm Hg). Volume of the extracorporeal circuit indicating venous pooling decreased more pronouncedly in the enoximone patients (-440 ml) than in the piroximone group (-300 ml). 4. Laser Doppler flows (LDFs) increased in both PDE-III inhibitor groups with the higher and longer increase in the enoximone-treated patients (LDF-forehead maximum +44%, LDF-forearm maximum +33%). Piroximone-induced increase in both LDFs was less pronounced with respect to both time and degree (LDF-forehead maximum +30%, LDF-forearm +12%). 5. Oxygen consumption (VO2) was significantly higher in the PDE-III inhibitor-treated than in the control patients. 6. Piroximone and enoximone showed significant vasodilatory properties at the arterial and venous side (= 'venous pooling'), from which patients with heart failure would profit. 7. Vasodilation could be observed for a longer period and was more pronounced in the enoximone-treated than in the piroximone patients. Alterations in capillary skin blood flow measured by laser Doppler technique gave evidence for an improvement in nutritive microcirculation, which was slightly more pronounced in the enoximone patients.

Influence of different anticoagulation regimens on platelet function during cardiac surgery.

Qualitative platelet defects are of great importance as a cause of bleeding in cardiac surgery. We have studied the effects of different anticoagulation regimens on platelet function in 60 patients undergoing elective aorto-coronary bypass grafting with cardiopulmonary bypass (CPB). Patients were allocated randomly to four groups (each group n = 15) to receive either: bovine heparin 300 u. kg-1 (standard); heparin 300 u. kg-1 followed by a continuous infusion of 10,000 u. kg-1 until the end of CPB; heparin 600 u. kg-1; or heparin 600 u. kg-1 in addition to high-dose aprotinin 2 million iu before CPB, 500,000 iu h-1 until the end of operation and 2 million iu added to the prime. Platelet function was evaluated by aggregometry (turbidometric technique) using adenosine triphosphate (ADP) 2.0 mumol litre-1, collagen 4 microliters ml-1, adrenaline 25 mumol litre-1 and saline solution (control) as inducers. Both maximum aggregation and maximum gradient of aggregation were measured in arterial blood samples before, during and after CPB until the first day after operation. Mean total dose of heparin given in groups 2, 3 and 4 was more than 50,000 u. and differed significantly from that of group 1 (28,150 (SD 4700)u.). Platelet aggregation variables were most depressed during CPB and until the end of surgery in groups 2 and 3 (maximum aggregation - 54% to - 75% of baseline values). In the postoperative period, platelet function recovered but did not completely reach baseline values in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolated circulatory response to intravenous administration of the ACE inhibitor enalaprilat.

The isolated vascular effects of intravenous administration of the angiotensin converting enzyme (ACE) inhibitor enalaprilat were investigated. Thirty male patients undergoing cardiopulmonary bypass (CPB) were studied. According to a randomized sequence, 0.04 mg kg-1 enalaprilat (low-dose, n = 10), 0.08 mg kg-1 (high-dose, n = 10) enalaprilat or saline solution as placebo (control group, n = 10) was given as an i.v. bolus during CPB. Changes in mean arterial pressure (MAP) and venous reservoir (RV) of the extracorporeal circulation were studied as indices of arterial resistance and venous capacitance. Mean arterial blood pressure (MAP) and peripheral vascular resistance (SVR) were significantly more reduced in the high-dose enalaprilat group (MAP: -36 mm Hg after 9 min; SVR: -836 dyn s cm-5) than in the low-dose group (MAP: -13 mm Hg after 10 min). Volume of the reservoir (RV) decreased in both enalaprilat treated groups indicating additional (dose-dependent) venous pooling effects of the substance (low-dose: -300 ml; high-dose: -520 ml; control group: -100 ml). Skin capillary blood flow measured by laser Doppler flowmetry (LDF) increased after injection of 0.04 mg kg-1 enalaprilat, whereas it decreased significantly when MAP fell markedly in patients treated with high-dose enalaprilat. I.v. enalaprilat had dose-dependent vasodilating properties in the arterial and venous vessel system indicating reduction in pre- and afterload. Microcirculation in both enalaprilat treated groups improved as long as reduction in blood pressure was not limited.

Closure of longitudinal sternotomy with absorbable sutures.

In a consecutive series of 150 patients who underwent open heart surgery, absorbable suture (PDS-Ethicon) were used for the closure of median sternotomy. One patient developed sternal dehiscence; wound complications or incompatibility with the suture material did not occur. With the technique of "double" PDS sutures, rapid and secure sternal closure can be performed even in cases of friability of the sternum without cutting through the sternal bone.

The effect of the anticoagulation regimen on endothelial-related coagulation in cardiac surgery patients.

Heparin is still the most commonly used anticoagulant in cardiac surgery necessitating cardiopulmonary bypass. In recent years, endothelial-related coagulation (e.g. thrombomodulin/protein C-system) has enlarged our knowledge of the regulation of haemostasis. In a controlled randomised study, the influence of different regimens of anticoagulation on the thrombomodulin/protein C-system was studied. Sixty patients undergoing elective coronary artery bypass grafting were randomly allocated into four groups (n = 15) to receive: 300 IU.kg-1 of heparin before bypass; 600 IU.kg-1 of heparin; 300 IU.kg-1 of heparin as bolus followed by a continuous infusion of 10 000 IU.h-1 until the end of bypass; or 600 IU.kg-1 of heparin plus 'high dose' aprotinin (2 million IU of aprotinin before bypass, 500 000 IU.h-1 until the end of the operation and 2 million IU added to the bypass pump prime). Grouping was blinded for the surgeon and the anaesthetist. Plasma concentrations of thrombomodulin, protein C and (free) protein S as well as thrombin/antithrombin III were measured by enzyme-linked-immunosorbent assays after induction of anaesthesia, during and after bypass, at the end of surgery, 5 h after bypass, and on the first postoperative day. Activated clotting time was significantly longer during bypass in group 2 (566 (60)s) and group 4 (655 (59)s), whereas standard coagulation parameters showed no differences between the four groups. Blood loss and use of homologous blood and blood products were highest in groups 2 and 3. Thrombomodulin plasma levels were similar (and normal) at baseline (< 40 ng.l-1), decreased during bypass and reached baseline values postoperatively without showing significant group differences. Protein C did not show any differences among the groups within the investigation period. 'Free' protein S plasma levels were most reduced in group 1 (from 68 (8)% to 48 (9)% after bypass). Thrombin/antithrombin III plasma concentrations increased most in groups 1 (to 69 (14) micrograms.l-1 after bypass) and 2 (to 48 (7) micrograms.l-1 after bypass), whereas they remained significantly lower in groups 3 and 4. The thrombomodulin/protein C-system was not significantly influenced by the regimen of anticoagulation. Administration of 'high-dose' heparin was associated with the highest blood loss, which could not be related to endothelial-associated coagulation.

Does aprotinin influence endothelial-associated coagulation in cardiac surgery?

Aprotinin has been reported to reduce bleeding in cardiac surgery patients. Its mechanisms of action on coagulation have not been fully elucidated. In a prospectively randomized study of 40 patients undergoing elective aortocoronary bypass grafting, the influence of high-dose aprotinin (2 million IU of aprotinin before CPB, 500,000 IU/h until the end of operation, 2 million IU added to the prime) (N = 20) on endothelial-related coagulation was compared to a nontreated control group (N = 20). Thrombomodulin (TM), protein C and (free) protein S as well as thrombin/antithrombin-III (TAT) plasma concentrations were measured by enzyme-linked immunosorbent assays (ELISA) before the aprotinin infusion, before cardiopulmonary bypass (CPB), during CPB and after CPB, at the end of surgery, 5 hours after CPB, and on the first postoperative day. All standard coagulation parameters (AT-III and fibrinogen plasma levels, platelet count, partial thromboplastin time) did not differ between the two groups. At baseline, TM plasma levels were within the normal range (< 40 ng/mL) and similar in both groups. During CPB, TM plasma concentrations decreased similarly in both groups (aprotinin: 18 +/- 6 ng/mL, control: 17 +/- 7 ng/mL) followed by a comparable increase in the postbypass period until the first postoperative day (aprotinin: 60 +/- 10 ng/mL, control: 53 +/- 11 ng/mL). Protein C and (free) protein S plasma levels also showed no differences between the two groups. On the first postoperative day, baseline values for protein C and protein S had not yet been reached.(ABSTRACT TRUNCATED AT 250 WORDS)