Development of a Gastight Thoracotomy Model for Investigation of Carbon Dioxide Field-Flooding Efficacy

Carbon dioxide (CO₂) field-flooding during cardiac surgery is a prevention technique to avoid blood-air contact and subsequent embolization. Although it was first used more than 60 years ago, there is still some perplexity around its efficacy, mainly because the gas is invisible and air embolization is difficult to quantify. An accurate assessment of field-flooding can, therefore, best be performed in models where various methods can be tried in a controlled environment and evaluated with industrial-grade sensors. Multiple options are available for anatomically correct models that reproduce a sternotomy situation, but models for minimally invasive cardiac surgery are expensive and normally meant for training of surgical techniques where only the top side of the model is important. We created a low-cost and "home-made" gastight mini-thoracotomy model with internal organs and left atrial incision to investigate CO₂ insufflation in a simulated minimally invasive mitral valve surgery. The model was validated with CO₂ field-flooding tests with a commercial diffuser, while three sensors continuously registered the local concentration of CO₂ gas.