Hematic Antegrade Repriming Reduces Emboli on Cardiopulmonary Bypass: A Randomized Controlled Trial

Abstract

Particulate and gaseous microemboli (GME) are side effects of cardiac surgery that interfere with postoperative recovery by causing endothelial dysfunction and vascular blockages. GME sources during surgery are multiple, and cardiopulmonary bypass (CPB) is contributory to this embolic load. Hematic antegrade repriming (HAR) is a novel procedure that combines the benefits of repriming techniques with additional measures, by following a standardized procedure to provide a reproducible hemodilution of 300 ml. To clarify the safety of HAR in terms of embolic load delivery, a prospective and controlled study was conducted, by applying Doppler probes to the extracorporeal circuit, to determine the number and volume of GME released during CPB. A sample of 115 patients (n = 115) was considered for assessment. Both groups were managed under strict normothermia, and similar clinical conditions and protocols, receiving the same open and minimized circuit. Significant differences in GME volume delivery (control group [CG] = 0.28 ml vs. HAR = 0.08 ml; p = 0.004) and high embolic volume exposure (>1 ml) were found between the groups (CG = 30.36% vs. HAR = 4.26%; p = 0.001). The application of HAR did not represent an additional embolic risk and provided a four-fold reduction in the embolic volume delivered to the patient (coefficient, 0.24; 95% CI, 0.08–0.72; p = 0.01), which appears to enhance GME clearance of the oxygenator before CPB initiation.

Haematic antegrade repriming to enhance recovery after cardiac surgery from the perfusionist side

“…The initiation of CPB with an empty venous line is a controverted perfusion strategy to reduce circulating volume and hemodilution, being required after the completion of HAR. Despite possible concerns about the emboli impact of any of both, there is recent evidence indicating that HAR represents a protective factor against emboli, reducing the embolic load delivered to the patient during CPB and the exposure to high embolic volumes [ 20 ]. Some authors pointed out that GME and sudden hemodilution play a major role in the aggression to endothelial glycocalyx, resulting in microvascular impairment, hypoperfusion, inflammatory response, and end-organ dysfunction [ 21 – 24 ].…”

Hematic Antegrade Repriming: A Reproducible Method to Decrease the Cardiopulmonary Bypass Insult

“…Despite the fact that VAVD application, in the range that is used, has been reported as safe in terms of postoperative complications (13), its overall impact in terms of evidence and the influence of the CPB initiation with and "empty venous line" still remains unclear (2). With these concerns in mind, a clinical trial to validate the embolic and neurocognitive impact reduction of HAR, in a short and mid-term postoperative period, is being conducted (21).…”

“…To improve the replicability of the procedure, the sequence has been divided into six simple steps (Figure 2) (11).…”

Cardiopulmonary bypass associated acute kidney injury: better understanding and better prevention

“…In animal studies, elevated levels of LME were found in the kidney after the CPB procedure and induced renal damage [ 120 ]; in a subsequent cardiac surgery patient cohort, filtration of LME was considered renoprotective [ 125 ]. Some optimization strategies for surgical methods (such as minimally invasive extracorporeal circulation (MiECC) [ 126 ] and hematic antegrade repriming 127 ] and modified devices [ 124 ] are both effective at reducing microemboli.…”