Establishment of swine-penetrating craniocerebral gunshot wound model

Abstract

Background: Bullet-induced brain wounds are common among military personnel in war zones and among civilians with gun accidents or crime-related gun injuries. The goal of this study was to develop a nonfatal porcine model of penetrating craniocerebral gunshot wound (PCGW) by firing a projectile in live swine to induce PCGW in such a realistic manner as to reconstruct their physical characteristics.

Materials and methods: We established a nonfatal porcine model of PCGW based on a custom-designed experimental gun that emulates the shooting of a 5.56-mm NATO standard rifle at 800 m (317 m/s; 200.9 J). Commercial swine (n = 20) were subjected to a ballistic wound to the bilateral frontal lobe, and four swine were used as controls. Surviving swine were used in subsequent first-aid, management, and monitoring experiments for neurosurgeons. Various physiological variables were measured continuously. After computed tomography (CT) scanning and three-dimensional CT reconstructions, all pigs underwent primary lifesaving emergency interventions, including emergency decompressive craniotomies and hemorrhage control.

Results: In our nonfatal porcine model of PCGW, injuries were comparable in their morphology to real gunshot wounds, as evidenced by analysis of wound characteristics and CT scan images. The survival rates of the pigs were 100% within 2 h, 95% within 6 h, 85% within 12 h, and 85% within 24 h (P < 0.01). Hemodynamics, hematology, blood routine biochemistry, coagulation, and other physiological parameters also exhibited significant changes in the PCGW pigs.

Conclusions: This model makes possible the laboratory reproduction of real ballistic wounds in a live large animal model that is close to humans.

Keywords: Animal models of injury; Bullet wound; Damage control; Gunshot wounds; Penetrating brain injury.