| 1. |
- Boivie, Patrik, et al.
(författare)
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Embolic material generated by multiple aortic crossclamping : a perfusion model with human cadaveric aorta
- 2003
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - 0022-5223 .- 1097-685X. ; 125:6, s. 1451-1460
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Atherosclerosis of the ascending aorta and use of aortic crossclamping are risk factors for neurologic injury during cardiac surgery. OBJECTIVES: Repeated aortic manipulation is part of the surgical approach to most cardiac operations. The aim of this study was to assess the amount and size of particulate matter that is dislodged from the aortic wall as a function of repeated aortic crossclamping. METHODS: In 10 subjects undergoing autopsy the aorta was dissected and mounted in a perfusion model. The ascending aorta was crossclamped and washed out 10 times, with the perfusate collected in aliquots (1 to 10). The aliquots were examined by computerized image processing, both macroscopically and under the microscope for calcified and cellular material. RESULTS: Aortic crossclamping produced substantial output of particulate matter. After repeated aortic crossclamping the number of particles decreased (P =.012) and approached the baseline for aliquots 6 to 10. The average particle diameter was 0.63 +/- 0.03 mm, with a maximum of 4.74 mm. Similar variability in particle outputs were recorded microscopically, with findings of both calcified and cellular material. Nine of 10 aortas had calcifications seen during simple visual inspection. CONCLUSIONS: The washouts of dislodge material at aortic crossclamping had embolic potential. During the initial aortic crossclamping procedures the amount of particles was substantial, both macroscopically and microscopically. On the microscopic scale noncalcified cellular debris represents a significant pool of embolic material. Repeated aortic crossclamping reduced the amount of particles. These findings question surgical techniques associated with repeated aortic crossclamping.
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| 2. |
- Ernofsson, Mats, et al.
(författare)
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Monocyte tissue factor expression, cell activation and thrombin formation during cardiopulmonary bypass : a clinical study
- 1997
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - 0022-5223 .- 1097-685X. ; 113:3, s. 576-584
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Cardiopulmonary bypass is associated with extensive thrombin generation and cell activation. Our main hypothesis in this study was that the expression of tissue factor on circulating monocytes contributes to the formation of thrombin. METHODS: Markers of activation of the coagulation cascade and cell activation were measured in 26 patients undergoing elective heart operations randomized to the use of heparin-coated (Duraflo II, n = 13) or standard cardiopulmonary bypass circuits (n = 13). RESULTS: Thrombin generation, measured as the thrombin-antithrombin complex, increased considerably during cardiopulmonary bypass with peak levels 3 hours afterward and with remaining elevation 20 hours later. Despite increased monocyte and granulocyte activation and increased levels of monocyte chemotactic protein-1, which upregulates monocyte tissue factor expression in vitro, monocyte tissue factor expression was not increased at the end of cardiopulmonary bypass. Furthermore, at this time the monocytes were less sensitive to in vitro stimulation by endotoxin. These results might be explained by simultaneous enhanced levels of interleukin-10, which effectively downregulates monocyte tissue factor expression in vitro. Twenty hours after cardiopulmonary bypass was discontinued, the tissue factor expression on freshly isolated monocytes and on monocytes stimulated by endotoxin was significantly increased compared with preoperative levels. At this time increased activation markers of granulocytes, monocytes, and lymphocytes were also recorded. None of the measured parameters was found to be different between the groups. CONCLUSIONS: The tissue factor expression on circulating monocytes is upregulated the day after heart operations. The clinical relevance and the regulatory mechanism behind the enhanced expression, however, are not fully elucidated.
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| 3. |
- Svedjeholm, Rolf, et al.
(författare)
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Metabolic and hemodynamic effects of intravenous glutamate infusion early after coronary operations
- 1996
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - 0022-5223 .- 1097-685X. ; 112:6, s. 1468-77
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Tidskriftsartikel (refereegranskat)abstract
- Amino acids, particularly glutamate, have been proposed to play an important role in the recovery of cardiac oxidative metabolism after ischemia. In this investigation, the metabolic and hemodynamic effects of glutamate infusion after coronary operations were studied. From 220 to 240 ml 0.1 mol/L l-glutamic acid solution was infused in 10 patients during 1 hour starting 2 hours after operation. A control group of 10 patients received an infusion of 240 ml saline solution. During glutamate infusion, there were significant increases in the uptake of glutamate (from 0.7 +/- 0.2 micromol/min in the basal state to a peak of 5.7 +/- 1.2 micromol/min at 20 minutes) and lactate (from 4.9 +/- 2.0 micromol/min in the basal state to 14.1 +/- 4.4 micromol/min at 60 minutes; p < 0.01), whereas the uptake and release of other substrates remained essentially unaffected. Arterial glutamate levels (in whole blood) increased from 103 +/- 10 micromol/L to 394 +/- 20 micromol/L at 60 minutes. Thirty minutes after discontinuation of the glutamate infusion, arterial levels had decreased to 129 +/- 17 micromol/L. The markedly improved utilization of lactate and the unchanged release of alanine together suggest that the oxidative metabolism of the heart was stimulated by glutamate. The metabolic changes were associated with improved myocardial performance. Left ventricular stroke work index increased from 26.8 +/- 2.1 gm x beat(-1) x m(-2) body surface area to 31.3 +/- 3.1 gm x beat(-1) x m(-2) body surface area during glutamate infusion. Metabolic support with amino acids may provide a means to improve recovery of metabolic and hemodynamic function of the heart early after cardiac operations.
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| 4. |
- Övrum, Eivind, et al.
(författare)
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Complement and granulocyte activation in two different types of heparinized extracorporeal circuits
- 1995
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - 0022-5223 .- 1097-685X. ; 110:6, s. 1623-1632
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Tidskriftsartikel (refereegranskat)abstract
- Complement and granulocyte activation were studied in cardiopulmonary bypass circuits completely coated with either end-attached covalent-bonded heparin, the Carmeda BioActive Surface, or with the Duraflo II bonded heparin, in combination with reduced systemic heparinization (activated clotting time > 250 seconds). The control groups were perfused with uncoated circuits and full heparin dose (activated clotting time > 480 seconds). Altogether 67 patients undergoing elective first-time myocardial revascularization were investigated, having extracorporeal perfusion with a Duraflo II coated circuit (n = 17), an identical but uncoated circuit (n = 17), a Carmeda coated circuit (n = 17), or an equivalent uncoated circuit (n = 16). During cardiopulmonary bypass, the C3 activation products C3b, iC3b, and C3c (C3bc) and the terminal SC5b-9 complemented complex increased markedly in all four groups compared with baseline, but significantly less in the two coated groups than in their control groups. Additionally, a significantly lower concentration of C3bc was observed in the Carmeda coated group, with maximal increase of median 28 AU/ml compared with 50 AU/ml in the Duraflo II coated group (p = 0.003). Similarly, in the Carmeda coated group, the maximal increase of terminal complement complex was considerably lower (0.8 AU/ml) than the levels recognized in the Duraflo II coated group (2.4 AU/ml) (p < 0.001). The release of the granulocyte activation myeloperoxidase and lactoferrin increased from the beginning of the operation, with peak levels at the end of bypass. A significant reduction of lactoferrin release was recognized when comparing the coated groups with the control groups. The difference between the two coated groups (Carmeda 228 micrograms/L; Duraflo II 332 micrograms/L; p = 0.05) was marginally significant. For myeloperoxidase, no significant differences were observed between the coated and uncoated groups. In conclusion, both types of heparin-coated circuits reduced complement activation and release of lactoferrin, but the Carmeda circuit proved to be more effective than the Duraflo II equipment.
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| 5. |
- Al-Rashidi, Faleh, et al.
(författare)
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A new de-airing technique that reduces systemic microemboli during open surgery: a prospective controlled study.
- 2009
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Ingår i: The Journal of thoracic and cardiovascular surgery. - : Elsevier BV. - 1097-685X .- 0022-5223. ; 138:1, s. 157-162
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We have evaluated a new technique of cardiac de-airing that is aimed at a) minimizing air from entering into the pulmonary veins by opening both pleurae and allowing lungs to collapse and b) flushing out residual air from the lungs by staged cardiac filling and lung ventilation. These air emboli are usually trapped in the pulmonary veins and may lead to ventricular dysfunction, life-threatening arrhythmias, and transient or permanent neurologic deficits. METHODS: Twenty patients undergoing elective true left open surgery were prospectively and alternately enrolled in the study to the conventional de-airing technique (pleural cavities unopened, dead space ventilation during cardiopulmonary bypass [control group]) and the new de-airing technique (pleural cavities open, ventilator disconnected during cardiopulmonary bypass, staged perfusion, and ventilation of lungs during de-airing [study group]). Transesophageal echocardiography and transcranial Doppler continually monitored the air emboli during the de-airing period and for 10 minutes after termination of the cardiopulmonary bypass. RESULTS: The amount of air embolism as observed on echocardiography and the number of microembolic signals as recorded by transcranial Doppler were significantly less in the study group during the de-airing time (P < .001) and the first 10 minutes after termination of cardiopulmonary bypass (P < .001). Further, the de-airing time was significantly shorter in the study group (10 vs 17 minutes, P < .001). CONCLUSION: The de-airing technique evaluated in this study is simple, reproducible, controlled, safe, and effective. Moreover, it is cost-effective because the de-airing time is short and no extra expenses are involved.
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| 6. |
- Al Rashidi, Faleh, et al.
(författare)
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Comparison of the effectiveness and safety of a new de-airing technique with a standardized carbon dioxide insufflation technique in open left heart surgery: A randomized clinical trial.
- 2011
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Ingår i: The Journal of thoracic and cardiovascular surgery. - : Elsevier BV. - 1097-685X .- 0022-5223. ; okt, s. 1128-1133
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We have compared the effectiveness, time required for de-airing, and safety of a newly developed de-airing technique for open left heart surgery (Lund technique) with a standardized carbon dioxide insufflation technique. METHODS: Twenty patients undergoing elective open aortic valve surgery were randomized prospectively to the Lund technique (Lund group, n = 10) or the carbon dioxide insufflation technique (carbon dioxide group, n = 10). Both groups were monitored intraoperatively during de-airing and for 10 minutes after weaning from cardiopulmonary bypass by transesophageal echocardiography and online transcranial Doppler for the severity and the number of gas emboli, respectively. The systemic arterial partial pressure of carbon dioxide and pH were also monitored in both groups before, during, and after cardiopulmonary bypass. RESULTS: The severity of gas emboli observed on transesophageal echocardiography and the number of microembolic signals recorded by transcranial Doppler were significantly lower in the Lund group during the de-airing procedure (P = .00634) and in the first 10 minutes after weaning from cardiopulmonary bypass (P = .000377). Furthermore, the de-airing time was significantly shorter in the Lund group (9 vs 15 minutes, P = .001). The arterial pH during the cooling phase of cardiopulmonary bypass was significantly lower in the carbon dioxide group (P = .00351), corresponding to significantly higher arterial partial pressure of carbon dioxide (P = .005196) despite significantly higher gas flows (P = .0398) in the oxygenator throughout the entire period of cardiopulmonary bypass. CONCLUSIONS: The Lund de-airing technique is safer, simpler, and more effective compared with the carbon dioxide insufflation technique. The technique is also more cost-effective because the de-airing time is shorter and no extra expenses are incurred.
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