Related Experiment Video
Updated: Aug 26, 2026
A New Hybrid Quantitative Evaluation Model for Axillary Junctional Hemorrhage in Swine
Published on: December 6, 2024
Trauma, hemorrhage, and the pulmonary hilum: Defining prolonged pulmonary hilar control in a swine model
Thomas M R McKinley1, Jonathan B Livezey, Taylor Williams
1Department of Surgery (T.M.R.M., J.B.L., T.W., A.A., T.K., D.R.C., M.C.A., J.P.K.); Department of Veterinary Medicine (L.E.R.); Department of Pathology (D.M.), Eisenhower Army Medical Center, Augusta, Georgia; Department of Thoracic Surgery, Medical College of Georgia, Augusta, Georgia (D.L.M.); Department of Surgery, Mount Carmel Health System, Columbus, Ohio (C.S.); Department of Surgery, Madigan Army Medical Center, Tacoma, Washington (J.P.K.).
Background:
Surgical clamping of the pulmonary hilum is the preferred method for hilar control in trauma. However, prolonged pulmonary ischemia has not been characterized in the setting of hemorrhagic shock. We sought to characterize the effect of prolonged unilateral pulmonary ischemia after various classes of hemorrhagic shock in an in vivo swine model. We hypothesize that progressive hemorrhagic shock will amplify the physiologic effects and histologic changes that occur due to pulmonary hilar clamping.
Methods:
The swine underwent a bilateral anterolateral thoracotomy followed by weight-based hemorrhage and left pulmonary hilar occlusion with hilar clamping. Subjects were randomized to one of five groups: control or class I to IV hemorrhagic shock. Hemodynamic data, laboratory values, and length of survival were recorded. Biopsies of the bilateral pulmonary parenchyma were obtained.
Results:
Twenty-six animals were randomized to control (N=5), Class I (N=6), Class II (N=6), Class III (N=6), and Class IV (N=3) hemorrhage shock. The Class I to III groups demonstrated improved survival compared with the Class IV group (p<0.01). For the left (clamped) lung, there was significantly increased inflammation immediately after clamping that incrementally increased over 4 hours in all groups (p<0.01). The right (nonclamped) lung had significantly increased inflammation 15 minutes after clamping that incrementally increased over 4 hours in all groups (p=0.03). This inflammation was similar between lungs and between groups regardless of the class of shock (p=0.46).
Conclusions:
Prolonged pulmonary hilar occlusion in Class I to III hemorrhagic shock does not significantly decrease survival. Severity of inflammation in both the occluded and contralateral lung is only increased by duration of hilar occlusion-not degree of hemorrhage-and consistently increased over the 240 minutes of occlusion. Our description of bilateral pulmonary histopathologic inflammatory changes from unilateral hilar occlusion is a novel finding, as is the minimal effect of hemorrhage on these changes. (J Trauma Acute Care Surg 2026;00:000-000 Copyright © 2026 Wolters Kluwer Health, LLC. All rights reserved.).
Level Of Evidence:
Therapeutic/Care Management; not applicable-basic science article.
