A Retrospective Analysis of the Clinical Use and Utility of Advanced Imaging in the Evaluation of Near-Hanging and Strangulation Injuries at a Canadian Level One Trauma Centre

Abstract

Introduction: Computed tomography (CT) of the neck is highly sensitive and may effectively rule-out cervical spine, cerebrovascular, and aerodigestive injuries after blunt and penetrating trauma. However, CT may be overutilized in the evaluation of hanging or strangulation injuries. The objective of this study was to determine the diagnostic yield of CT imaging among patients evaluated for hanging or strangulation mechanisms at a Canadian level-1 trauma center.

Methods: All adult patients evaluated for hanging or strangulation injuries over an eight-year period were reviewed. The primary outcome was the diagnostic yield of CT imaging for major aerodigestive, cervical spine, cerebrovascular, or neurological injuries. Multiple logistic regression were performed to determine predictive factors for the use of CT imaging and the identification of injury on imaging.

Results: Among 124 patients evaluated for hanging or strangulation injuries during the study period, 101 (80%) were evaluated with CT of the head or neck. A total of 26 injuries were identified in 21 patients (18 anoxic brain injuries, 4 aerodigestive, 3 cerebrovascular, and 1 of cervical spine injury). The overall diagnostic yield of neck CT for cervical injuries was 7.8%, 4.7% for laryngeal-tracheal injuries, 3.5% for carotid and vertebral artery injuries, and 1.1% for cervical spine injury. The diagnostic yield of CT head for anoxic brain injury was 22.8%. Factors predicting the use of CT imaging were abnormal physical exam findings (RR 1.7 95% CI [1.2, 2.3]) and transfer accepted by the trauma team leader (RR 1.3 95% CI [1.1, 1.5]).

Conclusion: CT imaging is often used in the evaluation of patients presenting with hanging or strangulation mechanisms. Seven cerebrovascular, aerodigestive, or cervical spine injuries were identified on imaging during the study period, representing a diagnostic yield of 7%. No injuries were identified among patient with a normal GCS or physical exam. Factors predicting the use of CT imaging included transfer accepted by the trauma team leader and abnormal physical exam findings. The variable clinical presentation of near-hanging and strangulation injuries and the relatively low diagnostic yield of CT imaging should prompt the development of tools and institutional protocols to guide the evaluation of hanging and strangulation injuries.

Keywords: Aerodigestive injury; BCVI; Blunt cerebrovascular injury; Cervical spine fracture; Hanging; Near-hanging; Pharyngeal injury; Strangulation; Suicide.