Optimizing Diagnostic Yield: Evidence Against Universal Computed Tomography Angiography for Traumatic Vertebral Artery Injury Screening – A Commentary on “Epidemiology and Screening of Traumatic Vertebral Artery Injuries at a Large Scandinavian Level 1 Trauma Center”

Jae Taek Hong

doi:10.14245/ns.2551774.887

Traumatic vertebral artery injury (tVAI) remains a diagnostically challenging entity in the context of acute trauma, where timely identification is crucial to preventing devastating posterior circulation strokes [1-3]. Although relatively infrequent, missed cases may result in irreversible neurological injury, underscoring the importance of efficient yet sensitive screening [4]. The authors [5] provide valuable real-world insight through a large-scale analysis of imaging trends at a Scandinavian level 1 trauma center, comparing periods of selective computed tomography angiography (CTA)-based screening with a later phase of universal screening. Across 2,843 trauma patients, the authors report a tVAI incidence of 2.2% and posterior circulation stroke in 0.9%, with a calculated number needed to image (NNI) of 46 to diagnose one tVAI and 114 to diagnose one stroke. Importantly, when screening shifted from selective imaging to near-universal CTA usage, the NNI nearly doubled—from 35 to 65 for tVAI and from 90 to 149 for stroke—yet the detection rate itself did not significantly improve (p=0.261). This observation suggests that universal screening increases imaging burden without necessarily enhancing diagnostic yield, supporting the practical value of a targeted, risk-based imaging approach in this trauma cohort. The high median New Injury Severity Score among tVAI patients (27) also emphasizes the close association between tVAI and severe polytrauma.

The authors [5] further investigated the relationship between Biffl grade and stroke occurrence, producing several findings that merit attention. Counter to traditional expectations, the highest proportional stroke rates occurred in lower-grade lesions—61.5% in grade II and 42.9% in grade I—rather than in severe grades.

Although grade IV lesions, the most common in this series, accounted for the largest number of strokes overall, the unexpectedly high incidence among grades I and II suggests that luminal narrowing alone may not reliably predict stroke risk and that even minimal-grade dissections may represent unstable vascular pathology. Grade III and V cases were few, limiting interpretation, yet the observation remains provocative, indicating that ischemic risk may not follow a purely grade-dependent pattern and calling for broader multicenter data. The fact that 20% of strokes occurred in the setting of bilateral injury further highlights the vulnerability of the posterior circulation when both vertebral arteries are compromised.

The implications of preoperative tVAI detection for spinal trauma surgery are substantial [4,6]. Antithrombotic therapy may be initiated promptly when injury is identified, but its influence extends further into operative planning. When a vertebral artery injury is present, surgical strategies must be adapted to preserve remaining vascular integrity. Particularly in unilateral injuries, the contralateral vertebral artery may become the sole supply to the posterior circulation, making even minor iatrogenic injury catastrophic. This reality necessitates careful avoidance of high-risk screw trajectories within the cervical pedicle or areas adjacent to the foramen transversarium. Spine stabilization in such scenarios must privilege safety; for C2 instrumentation, laminar or pars screws provide safer alternatives, and from C3 to C7, lateral mass screws should be favored where feasible [7-9]. In higher-grade cases—including pseudoaneurysms—pre-emptive endovascular treatment may be indicated prior to fixation to avoid intraoperative rupture. Ultimately, the authors’ findings affirm that selective screening captures most clinically relevant injuries and provides the information required to guide safe surgical decision-making, particularly when fracture patterns meet established tVAI screening criteria.

Taken together, this study supports the efficiency and diagnostic sufficiency of a selective CTA-screening strategy for suspected tVAI, demonstrating no clear detection advantage with wider imaging utilization. These data reinforce clinician judgment in selective protocols and highlight the potential for improved cost-effectiveness when screening is guided by well-defined risk features. Future research should focus on refining a simplified prediction rule tailored to spine trauma, particularly given that 85% of tVAI cases in this series were associated with cervical fractures. Stratification of fracture patterns—especially upper cervical and foramen transversarium involvement—may allow more precise risk allocation and further lower the NNI. Longitudinal outcome studies comparing antithrombotic regimens, timing, and neurologic recovery would also help to define optimal management. The authors [5], therefore, contribute meaningfully to the ongoing conversation around screening efficiency, and their work underscores the central role that targeted vascular imaging plays in reducing stroke risk and informing safe operative planning in cervical spine trauma.