Biffl scale for blunt cerebrovascular injury

The Biffl scale or grade illustrates the spectrum of blunt cerebrovascular injury (BCVI) seen on angiography (both CTA and DSA). Some authors refer to the grading scale as the Denver scale, which is not to be confused with the Denver criteria, a series of clinical indications to screen for blunt cerebrovascular injury in trauma patients. 

Classification

• grade I: mild intimal injuryluminal irregularity or irregular intimadissection with <25% luminal narrowing
• grade II: dissection or intramural hematoma with ≥25% luminal narrowing, intraluminal thrombus, or raised intimal flap / intramural haematoma with luminal narrowing >25% / intraluminal thrombosis
• grade III: pseudoaneurysm
• grade IV: vessel occlusion/thrombosis occlusion
• grade V: vessel transection, including transection with free extravasation

arteriovenousArteriovenous fistula (although this was not specified in the original definition is often included with transections (grade V) ^4,5. However, Biffl et al. initially described fistulae as grade I if small and grade III if large ¹, and later revised this description to grade II if small and grade V if hemodynamically significant ⁶. Other authors have proposed classifying these lesions as grade III ⁷.

Treatment and prognosis

This grading system has prognostic and therapeutic implications.

The risk of stroke increases with increasing grade of carotid artery injury ¹:

• grade I: 8%
• grade II: 14%
• grade III: 26%
• grade IV: 50%
• grade V: 100%

The risk of stroke does not correlate with increasing grade of vertebral artery injury ³:

• grade I: 6%
• grade II: 38%
• grade III: 27%
• grade IV: 28%