When do cerebral emboli appear during open heart operations? A transcranial Doppler study

Linden, Jan van der; Casimir-Ahn, Henrik

doi:10.1016/0003-4975(91)90793-p

Cited by 203 publications

(88 citation statements)

References 12 publications

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“…Thus, it is then that the difference in the number of microemboli between the CO 2 treated patients and the controls comes to the fore. 7 Moreover, it should be kept in mind that in the CO 2 treated patients the microemboli were not only fewer in number but they also differed from those in the untreated group as to their composition. They consisted of CO 2 and not of air.…”

Section: Number and Behavior Of Air Microembolimentioning

confidence: 95%

“…The second peak is in accordance with our earlier transcranial Doppler study during open-heart surgery, in which we found that most microemboli reached the brain during and after weaning from CPB. 7 By contrast, only very few emboli passed the middle cerebral artery after release of the aortic clamp until the heart started to eject blood. Thus, most microemboli that appear in the heart after release of the cross-clamp stay there until the beating heart is being filled.…”

Section: Number and Behavior Of Air Microembolimentioning

confidence: 99%

“…6 It has been found that, even if these techniques are meticulously adhered to, large numbers of microemboli still occur. [6][7][8] Consequently, other methods should be explored to rid the heart and the arteries of air bubbles. …”

Section: Introductionmentioning

confidence: 99%

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Carbon dioxide de‐airing in cardiac surgery

Svenarud¹

2006

Acta Anaesthesiol Scand

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(ENG)Background: The risks connected with the presence of air microemboli in open-heart surgery, have recently been emphasized by reports that their number is correlated with the degree of postoperative neuropsychological disorder. Insufflation of carbon dioxide (CO 2 ) into the chest wound is used in open-heart surgery to de-air the heart and great vessels. A new insufflation device, a gas-diffuser, was compared with traditional devices for de-airing in an experimental wound model. Finally, to assess the clinical value of CO 2 insufflation into the cardiothoracic wound, the effect of such insufflation on the incidence and behavior of microemboli in the heart and ascending aorta was studied under the conditions of a randomized clinical trial. Methods: In a cardiothoracic wound model, a full-size torso, the degree of air displacement achieved by the gas-diffuser, was compared with that of a 2.5 mm open-ended tube, a 6.35 mm open-ended tube, a multi-perforated catheter, and a gauze sponge, respectively, during steady state. The influence of suction, varying CO 2 flow rates, an open pleural cavity, exposure to fluids and the position of the device were also evaluated. De-airing was assessed by measuring the remaining air content at the right atrium. In the trial, twenty (20) patients undergoing single valve surgery were randomly divided into two groups. Ten patients were insufflated with CO 2 via a gas-diffuser and ten were not. Microemboli were ascertained by intraoperative transesophageal echocardiography (TEE) from release of the aortic cross-clamp until 20 minutes after end of cardiopulmonary bypass (CPB). Results: During steady state, the gas-diffuser produced efficient air displacement in the wound cavity model at CO 2 flows of ³5 l/min (£0.65% remaining air), while the 2.5mm and 6.35mm open-ended tube were much less efficient with ³82% and >19.5% remaining air, respectively, at 2.5-10 l/min CO 2 flows (p<0.001). When using the gas-diffuser, an open pleural cavity prolonged the time needed to obtain a high degree of air displacement in the wound cavity (p=0.001). With suction of 10 l/min the median air content was still low (£0.50%) at a simultaneous CO 2 flow of 10 l/min. Conversely, suction of 25 l/min caused a marked increase in air content both at a CO 2 flow of 5 and 10 l/min (p<0.001). When exposed to fluid, the gauze sponge and the multi-perforated catheter immediately became inefficient (70% and 96% air, respectively), whereas the gas-diffuser remained efficient (0.4% air). The two patient groups did not differ in clinical parameters. The median number of microemboli registered during the whole study period was 161 in the CO 2 group versus 723 in the control-group (p<0.001). Corresponding numbers for the left atrium were 69 versus 340 (p<0.001), left ventricle 68 versus 254 (p<0.001), ascending aorta 56 versus 185 (p<0.001). In the CO 2 group the median number of detectable microemboli after CPB fell to zero 7 minutes after CPB versus 19 minutes in the control group (p<0.001). Conclusion:The ...

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Section: Number and Behavior Of Air Microembolimentioning

confidence: 95%

Section: Number and Behavior Of Air Microembolimentioning

confidence: 99%

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Carbon dioxide de‐airing in cardiac surgery

Svenarud¹

2006

Acta Anaesthesiol Scand

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“…despite thorough surgical de-airing, new microemboli continued to pop up in the left atrium even up to 20 minutes after cPB had ended (30). Van der Linder found the highest microemboli counts occurred during heart filling; they were shown to be the consequence of inadequate de-airing procedures (31). when the beating heart was being filled and started to eject blood during weaning from cPB, most of the microemboli originating from the pulmonary veins were propagated forward to the left ventricle and finally ejected into the ascending aorta.…”

Section: Surgical Interventionsmentioning

confidence: 99%

Generation, Detection and Prevention of Gaseous Microemboli during Cardiopulmonary Bypass Procedure

Lou

Liu

et al. 2011

Int J Artif Organs

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Neuropsychological injury after cardiopulmonary bypass (CPB) is one of the most serious and costly complications arising from the procedure. Gaseous microemboli (GME) have long been implicated as one of the principal causes. There are two major sources of GME: surgical and manual manipulation of the heart and arteries; and the components of the extracorporeal circuit, including the type of pump, different perfusion modes, the design of the oxygenator and reservoir, and the use of vacuum assisted venous drainage (VAVD), all of which have a great impact on the delivery of existing GME to the patients. Transcranial Cranial Doppler (TCD) has been used for more than two decades to assess and monitor the quality of extracorporeal perfusion with regard to the blood flow velocity of the middle cerebral arteries (MCA) and emboli detection, contributing to the achievement of better perfusion results. The Emboli Detection and Classification (EDAC) Quantifier has been able to detect and track microemboli in CPB circuits up to 1,000 microemboli per second at flow rates ranging from 0.2 L/min to 6.0 L/min. The deleterious effects of GME are multiple, including damage to the cerebral vascular endothelium, disruption of the blood-brain barrier, complement activation, leukocyte aggregation, increased platelet adherence, and fibrin deposition in the micro-vasculature. Improvements in perfusion equipment and in perfusion and surgical techniques have led to a dramatic reduction in the occurrence of GME during cardiac surgery. Although the clinical relevance of cerebral air embolization in causing neurological damage is unclear, every single person involved in perfusion and surgical technology should be aware of the risk of embolization and strictly regulate clinical behavior. Related research should also be done to improve the design of circuit components and clinical practice with a view to eliminating air bubbles during CPB procedure.

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“…The reason for this is primarily the incidence of stroke or cerebrovascular insult (ICV) as one of the most serious CABG complications (13). Numerous studies have shown that the risk of occurrence of ICV during CABG is in direct correlation with the degree of carotid stenosis (14). As a consequence a common strategy for the treatment of such patients was "carotid before coronary" that is, first, an operation on the carotid arteries (CEA) and only then CABG in two parts, or as a simultaneous operation (15).…”

Section: Introductionmentioning

confidence: 99%