Experimental in vivo surgical study on porcine eyes.
Experimental PPV under general anesthesia was performed on porcine eyes (Yorkshire species) at a University Surgical Training & Education Center. Infusion cannulas were placed into the suprachoroidal space and fluid–air exchange (FAE) was started with sequential increases in infusion air pressure. Vital signs of porcine animals were continuously monitored and recorded in real time during the PPV, including end-tidal carbon dioxide (ETCO2), oxygen saturation (SaO2), intra-arterial blood pressure, electrocardiography (EKG), and transesophageal echocardiography (TEE).
Intracardiac air was detected on TEE less than 30 seconds after increasing air infusion pressure to 60 mm Hg. ETCO2 declined precipitously, followed by hypotension and EKG changes. Oxygen desaturation was a late phenomenon. The animal died within 7 minutes of VAE. During autopsy, the heart was open under water and air escaped from the right ventricle.
This in vivo porcine model confirms that during the FAE in PPV, pressurized air from an infusion cannula malpositioned in the suprachoroidal space can transit through the eye to the central circulation, resulting in fatal VAE.