Introduction: Blunt traumatic cerebrovascular injury (TCVI) represents structural injury to a vessel due to high-energy trauma. The Biffl Scale is a widely accepted grading scheme for these injuries that was developed using digital subtraction angiography. In recent years, screening computed tomography angiography (CTA) has been used to identify patients with TCVI. The reliability of this scale, using CTA, has not yet been determined.

Methods: Seven independent raters, including two neurosurgeons, two neuroradiologists, two neurosurgical residents, and one neurosurgical vascular fellow independently reviewed a presenting CTA of the neck performed on 40 patients with confirmed TCVI and assigned a Biffl grade. Ten images were repeated to assess intra-rater reliability, for a total of 50 CTAs. Fleiss's multi-rater kappa (?) and interclass correlation (ICC) were calculated as a measure of inter-rater reliability. Weighted Cohen’s kappa (?) was used to assess intra-rater reliability.

Results: Fleiss's multi-rater kappa was 0.65 (95% CI 0.61 - 0.69), indicating substantial agreement as to the Biffl grade assignment among the seven raters. Interclass correlation was 0.82 demonstrating excellent agreement among the raters. Intra-rater reliability was perfect (weighted Cohen’s kappa = 1) in two raters and near perfect (weighted Cohen’s kappa > 0.8) in the remaining 5 raters.

Conclusions: Grading of TCVI with CTA using the Biffl Scale is reliable.

Patient Care: The Biffl scale for the grading of traumatic cerebrovascular injury (TCVI) is widely accepted. The scale was derived using digital subtraction angiography. However, current screening for TCVI primarily utilizes computed tomography angiography (CTA). In order for the scale to be robust in both clinical practice and research, its reliability must be proven. We demonstrate that grading of TCVI with CTA using the Biffl scale is reliable. This supports its use in both clinical and academic endeavors.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) describe the Biffl scale for the grading of traumatic cerebrovascular injury, 2) apply the Biffl scale, 3) and comprehend the inter- and intra-rater reliability of the Biffl scale.

References: 1. Fusco MR, Harrigan MR. Cerebrovascular dissections: a review. Part II: blunt cerebrovascular injury. Neurosurgery 2011; 68(2):517-30; discussion 530. 2. Griessenauer CJ, Fleming JB, Richards BF, et al. Timing and mechanism of ischemic stroke due to extracranial blunt traumatic cerebrovascular injury. J Neurosurg 2013; 118(2):397-404. 3. Stein DM, Boswell S, Sliker CW, et al. Blunt cerebrovascular injuries: does treatment always matter? J Trauma 2009; 66(1):132-43; discussion 143-4. 4. Kerwin AJ, Bynoe RP, Murray J, et al. Liberalized screening for blunt carotid and vertebral artery injuries is justified. J Trauma 2001; 51(2):308-14. 5. Biffl WL, Moore EE, Offner PJ, et al. Blunt carotid arterial injuries: implications of a new grading scale. J Trauma 1999; 47(5):845-53. 6. Walter SD, Eliasziw M, Donner A. Sample size and optimal designs for reliability studies. Stat Med 1998; 17(1):101-10. 7. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977; 33(1):159-74. 8. Roberts DJ, Chaubey VP, Zygun DA, et al. Diagnostic accuracy of computed tomographic angiography for blunt cerebrovascular injury detection in trauma patients: a systematic review and meta-analysis. Ann Surg 2013; 257(4):621-32. 9. Eastman AL, Chason DP, Perez CL, et al. Computed tomographic angiography for the diagnosis of blunt cervical vascular injury: is it ready for primetime? J Trauma 2006; 60(5):925-9; discussion 929. 10. Malhotra AK, Camacho M, Ivatury RR, et al. Computed tomographic angiography for the diagnosis of blunt carotid/vertebral artery injury: a note of caution. Ann Surg 2007; 246(4):632-42; discussion 642-3. 11. Stapf C, Hofmeister C, Hartmann A, et al. Interrater agreement for high grade carotid artery stenosis measurement and treatment decision. Eur J Med Res 2000; 5(1):26-31. 12. Endarterectomy for asymptomatic carotid artery stenosis. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. JAMA 1995; 273(18):1421-8. 13. North American Symptomatic Carotid Endarterectomy Trial C. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med 1991; 325(7):445-53.