AAST Cervical Vascular Injury Scale (Biffl/Denver)

Choice of scale: For cervical vascular injury—especially blunt cerebrovascular injury (BCVI)—the clinically dominant grading system is the Biffl (Denver) scale. AAST materials state that BCVIs are graded according to the Denver grading scale, which is incorporated into the AAST OIS for cervical vascular injury. Therefore this calculator uses Biffl grades I–V rather than a separate vessel-name hierarchy (as used for thoracic/abdominal vascular OIS). Grades: I intimal irregularity or dissection/IMH with <25% narrowing; II dissection/IMH with ≥25% narrowing, intraluminal thrombus, or raised flap; III pseudoaneurysm; IV occlusion; V transection with free extravasation. Lower grades are usually managed with antithrombotic therapy when safe; higher grades may need endovascular or open intervention. Stroke risk rises with grade.