Design of in vitro flow loop aimed at improving hemodynamic conditions around the total cavopulmonary connection in patients with failing Fontan.
Open Access
- Author:
- Nichols, Claire
- Area of Honors:
- Biomedical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Keefe B Manning, Thesis Supervisor
Meghan Vidt, Thesis Honors Advisor
Justin Lee Brown, Faculty Reader - Keywords:
- Fontan
Total Cavopulmonary Connection
Hemodynamics
flow
pressure
failing fontan - Abstract:
- The Fontan procedure is the final procedure in staged reconstruction heart surgery that alters the normal blood flow pattern and anatomy to treat congenital heart conditions. The root problem of many of these conditions is that one side of the heart is working overtime to compensate for the side that is not working as well. The Fontan procedure is crucial because without intervention, there is significant strain on the working side of the heart and the blood reaching the body is not sufficiently oxygenated. Since this is done on young patients, the long-term effects have only recently been discovered. The failing Fontan has many possible negative side effects, such as hypertension and decreased exercise performance. The goal of this project is to develop an in vitro flow loop that incorporates a patient-specific Fontan anatomy and recapitulates pathological Fontan conditions to assist in future research of a novel palliative surgical strategy for patients with failing Fontan. This includes matching pressure and flow rates to clinically observed values. This project tests if the addition of an attachment to the right ventricle lowers the pressure and decreases power loss. Heart rates of 75, 60, and 45 beats per minute are analyzed to observe differences in the deformation of the inferior vena cava. There are no differences in the pressure with the addition of linear actuators mimicking surgical intervention. The power loss of the junction has also been analyzed to see how the addition of the linear actuators changed the power loss because it can be an indicator of exercise performance and endurance. The power loss increases at heart rates of 75 and 45 beats per minute, but it decreases at heart rates of 60 beats per minute. Overall, the heart rate of 60 beats per minute yields the best results because it lowers the power loss and decreases the average pressure in the pulmonary arteries. Despite inconsistent results, the development of the flow loop described in this study provides an experimental framework for testing alternative connection options to the atrioventricular valve. In conclusion, this study is a great step towards figuring out if Fontan circulation can be improved with the addition of a connection between the inferior vena cava and the right ventricle.