A Vascular Catastrophe during Endonasal Surgery: An Endoscopic Sheep Model.

Internal carotid artery (ICA) injury is a dramatic complication of endonasal skull base approaches with massive bleeding. This study aims to design an animal model of ICA injury during endonasal skull base surgery. Eight sheep underwent ICA isolation followed by arterial pressure monitoring and placement of a rapid infuser. The Sinus Model Otorhino Neuro Trainer (Pro Delphus, Pernambuco, Brazil) nasal model was then modified. A novel posterior sphenoid wall was created, allowing the artery to be placed within and fixed to the model in a watertight fashion. A diamond-tipped bur allowed surgical exposure of the carotid artery. A standardized injury was created endoscopically. The "two-surgeon technique" allowed local packing measures to be performed. Outcome measures were mean arterial pressure (MAP) following injury, resuscitation fluid volume, survival time, and total blood loss. Mean preinjury weight was 51.8 ± 4.59 kg. All baseline hematologic parameters fell within normal limits. The mean preinjury and postinjury MAP was 65.7 ± 9.3 mm Hg versus 39.1 ± 6.9 mm Hg, respectively. The mean survival time was 50.25 ± 17.89 minutes, with mean resuscitation fluid volume of 10.89 ± 2.40 L and mean blood loss of 4943 ± 1089 mL. This model replicates the endoscopic surgical field of an ICA injury, with the potential to train endoscopic skull base teams in the skills require to manage an ICA injury.