Evaluation of emergency pulmonary hilar control for lethal vascular injury in swine.

Abstract

Traumatic pulmonary hilar injuries are rapidly fatal requiring decisive control for survival. There is currently insufficient data comparing hilar control techniques to make recommendations. We sought to determine the optimal maneuver to control massive pulmonary hilar hemorrhage in a live swine model. Sus scrofa swine underwent a left anterolateral thoracotomy followed by penetrating injury to the superior pulmonary vein. Animals were randomized to one of three groups: control group (CG)-no intervention, hilar clamp (clamp), or a hilar twist (twist) maneuver. Animals were monitored for 1 hour after intervention. Biopsies of the bilateral pulmonary parenchyma were obtained to compare the effect of the intervention. Twenty animals were included as CG (n = 5), clamp (n = 7), or twist (n = 8). Clamp animals had a significantly increased survival time ( p = 0.038). Blood loss was significantly increased in the CG compared with the clamp and twist groups ( p < 0.001). There was not any difference in blood loss between the clamp and twist groups ( p = 0.29). The time to complete the intervention was significantly shorter in the clamp compared with the twist cohort ( p = 0.006). Fifty-seven percent of clamp animals required additional interventions to control the hemorrhage compared with 12.5% of twist animals ( p = 0.067). One hundred percent of the CG animals required vasopressor support compared with 0% of the clamp animals ( p < 0.001) and 25% of the twist animals ( p = 0.001). Histologic inflammatory scores of the twist parenchyma were significantly higher compared with the clamp and CG ( p = 0.02 and p = 0.01 respectively). Pulmonary hilar control is a critical skill in trauma to control life-threatening exsanguination. Hilar clamping may be a superior maneuver for temporizing hilar trauma.