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Updated: Aug 10, 2026
Cardiopulmonary Bypass in a Mouse Model: A Novel Approach
Published on: September 22, 2017
A model for cardiopulmonary bypass redesign
R C Groom1, D S Likosky, R J Forest
1Maine Medical Center, Cardiac Surgery Division, Portland, ME 04102, USA. groomr@mmc.org
Insights
This study monitored brain injury precursors during cardiac surgery. Findings reveal specific bypass procedures increase embolic activity and hypoperfusion, informing safer surgical techniques.
Area of Science:
- Neurology
- Cardiovascular Surgery
- Biomedical Engineering
Background:
- Cardiac surgery can cause brain injuries via embolism and hypoperfusion.
- Cardiopulmonary bypass (CPB) is implicated in these neurological deficits.
- Understanding CPB's role is crucial for preventing brain injury.
Purpose of the Study:
- To understand processes causing embolic activity during CPB.
- To investigate cerebral hypoperfusion and hemodynamic changes during CPB.
- To link specific surgical events to neurological injury precursors.
Main Methods:
- Developed a system for simultaneous recording of physiological data, embolic activity, and cerebral oxygenation (NIRS).
- Synchronized all data with surgical video for detailed analysis.
- Related embolic events and NIRS changes to surgical and CPB care processes via video review.
Main Results:
- Observed significant patient variation in embolic counts and NIRS.
- Identified specific CPB events (e.g., venous drainage, air entrainment, drug injection) linked to increased embolism.
- Correlated NIRS changes with hypotension and heart positioning during grafting.
Conclusions:
- The developed monitoring system provides insights into CPB's contribution to neurological injury precursors.
- Data can guide surgical teams in refining CPB systems and techniques to minimize brain injury risk.
Introduction:
A portion of patients undergoing cardiac surgery may develop focal and/or subtle brain injuries secondary to cardiac surgery. There is evidence that, in some cases, these injuries may be related to cardiopulmonary bypass (CPB). Embolism and hypoperfusion are the dominant mechanisms for focal neurologic injuries among coronary artery bypass graft (CABG) surgery patients. Recent studies suggest that these mechanisms may also produce the more prevalent subtle neurological deficits. The aim of our current work is to obtain a thorough understanding of the processes of care associated with the production of embolic activity, cerebral hypoperfusion, and hemodynamic aberrations that often occur during CPB.
Methods:
We developed a system for simultaneous recording of physiologic parameters, embolic activity in the CPB circuit and in the cerebral arteries, and near infrared regional cerebral oxyhemoglobin saturation (NIRS) during cardiac surgery. All data were synchronized with a video recording of the surgical procedure. Periods of embolic activity and NIRS were subsequently related to surgical and CPB processes of care through a systematic review of the patient's surgical case video.
Results:
To date, we have enrolled 47 patients undergoing coronary and/or valvular procedures. We have observed wide variation across patients in detected cerebral embolic counts, NIRS and physiologic parameters. We have identified increased embolic counts in the CPB circuit related to specific processes and events such as the method of venous drainage, the entrainment of air in the venous line, the injection of medications into the CPB circuit and blood sampling from the CPB circuit. A portion of detected changes in NIRS were related to periods of hypotension and positioning of the heart during the construction of distal coronary artery grafts on the posterior coronary artery vessels.
Summary:
Use of this model provides the surgical team with detailed information regarding the contribution of CPB to the creation of precursors of neurological injury. This system provides meaningful data to guide the surgical team in the redesign of the CPB system and associated techniques.
