Digital Carotid Compression: A Simple Method to Reduce Solid Cerebral Emboli During Cardiac Surgery

ASNM and ASN joint guidelines for transcranial Doppler ultrasonic monitoring: An update

Today, it seems prudent to reconsider how ultrasound technology can be used for providing intraoperative neurophysiologic monitoring that will result in better patient outcomes and decreased length and cost of hospitalization. An extensive and rapidly growing literature suggests that the essential hemodynamic information provided by transcranial Doppler (TCD) ultrasonography neuromonitoring (TCDNM) would provide effective monitoring modality for improving outcomes after different types of vascular, neurosurgical, orthopedic, cardiovascular, and cardiothoracic surgeries and some endovascular interventional or diagnostic procedures, like cardiac catheterization or cerebral angiography. Understanding, avoiding, and preventing peri- or postoperative complications, including neurological deficits following abovementioned surgeries, endovascular intervention, or diagnostic procedures, represents an area of great public and economic benefit for society, especially considering the aging population. The American Society of Neurophysiologic Monitoring and American Society of Neuroimaging Guidelines Committees formed a joint task force and developed updated guidelines to assist in the use of TCDNM in the surgical and intensive care settings. Specifically, these guidelines define (1) the objectives of TCD monitoring; (2) the responsibilities and behaviors of the neurosonographer during monitoring; (3) instrumentation and acquisition parameters; (4) safety considerations; (5) contemporary rationale for TCDNM; (6) TCDNM perspectives; and (7) major recommendations.

Manual Carotid Compression is a Viable Alternative for Reduction of Cerebral Microemboli

BACKGROUND

Stroke is a devastating complication of cardiovascular surgeries, and the risk is particularly high for those requiring cardiopulmonary bypass (CPB). Embolic particles generated during the unclamping of the aortic cross-clamp may enter the cerebral circulation, lodging in small vessels. External manual compression of the carotid arteries is a non-invasive technique that has been proposed for cerebral protection during CPB procedures but is not widely deployed.

METHODS

The aim of this study is to assess the potential for cerebral emboli reduction with carotid compression using an in vitro model. Experiments were performed with a glass aortic arch model in a mock cardiovascular circuit. Small fluorescent particles were released into the circulation with and without carotid compression, and the particles visualized in the aortic midplane. The number of particles in the aorta and arch branch vessels were counted from the images before, during and following the release of carotid compression for durations of 10, 15 and 20 s. A gamma variate function was fit to the data to describe the bolus dynamics.

RESULTS

Carotid compression for 10 s reduces the number of embolic articles entering the carotid arteries by over 75%. A compression duration of 15-20 s does not result in greater particle reduction than one of 10 s.

CONCLUSION

Brief compression of the common carotid arteries during cardiovascular interventions has the potential to dramatically reduce the number of cerebral emboli and should be investigated further.

Mechanisms of perioperative brain damage in children with congenital heart disease

Congenital heart disease, particularly cyanotic congenital heart disease (CCHD), may lead to a neurodevelopmental delay through central nervous system injury, more unstable central nervous system development, and increased vulnerability of the nervous system. Neurodevelopmental disease is the most serious disorder of childhood, affecting the quality of life of children and their families. Therefore, the monitoring and optimization of nerve damage treatments are important. The factors contributing to neurodevelopmental disease are primarily related to preoperative, intraoperative, postoperative, genetic, and environmental causes, with intraoperative causes being the most influential. Nevertheless, few studies have examined these factors, particularly the influencing factors during early postoperative care. Children with congenital heart disease may experience brain damage during early heart intensive care due to unstable haemodynamics and total body oxygen transfer, particularly early postoperative inflammatory reactions in the brain, blood glucose levels, and other factors that potentially influence long-term neural development. This study analyses the forms of structural and functional brain damage in the early postoperative period, along with the recent evolution of research on its contributing factors.