Penetrating neck trauma: A review of image-based evaluation and management

Abstract

APPLIED RADIOLOGY © n 17 January 2016 Perhaps nowhere else in the human body is there a collection of vital structures packed into such a small space than in the neck. This anatomic consideration is a key factor contributing to the overall mortality of penetrating injuries to the neck, which ranges from 2-10%. 1-6 Added to this anatomic complexity is the fact that patients may have clinically silent or unsuspected injuries that require intervention.6-10 Historically, a low threshold for surgical exploration was employed, owing to the fear of missing a clinically occult vascular or aerodigestive injury,7, 8 all the while acknowledging that approximately 50-60% of these explorations would be nontherapeutic.1-3,11,12 Management algorithms based on neck zonal anatomy (Table 1) and wound depth were developed in the 1970’s.7-9,13-18 Using this approach, patients with wounds to zone II of the neck underwent mandatory exploration, regardless of patient vital signs and additional physical findings. Due to the difficult surgical exposure, zone I and zone III injuries were managed with a battery of invasive and semi-invasive tests, including catheter angiography, endoscopy, laryngoscopy and esophagography, all of which have focused utility and are tailored to evaluating specific anatomy.11, 19-22 These tests require additional time and expertise, which may not always be available at all centers. A more comprehensive test to limit evaluation time and optimize resources was therefore desirable. CT angiography (CTA) has emerged as a quick, reliable and accurate tool for evaluating these patients;1, 5-7, 10, 23-27 the modality is highly accurate in diagnosing and excluding injuries requiring intervention, and it has been shown to significantly decrease nontherapeutic surgical neck explorations.1, 4, 6, 7, 10, 13, 1618, 24-28 Indeed, the shift away from management dictated by wound location and depth to a “no zone,” image-based approach has been driven primarily by CTA.5, 6, 10, 17, 23, 24, 29 A recent prospective multicenter trial evaluating 40and 64-slice MDCT for cervical vascular and aerodigestive injuries has confirmed its accuracy and utility in patients with “soft signs” in the setting of penetrating neck injuries (Table 2).10 This review focuses on image-based evaluation and management as dictated by neck CTA. Strategies, pearls and pitfalls will be emphasized using an anatomical approach.