The Utility of a Screening Protocol for Blunt Cerebrovascular Injury Using Computed Tomographic AngiographyMichael Tso, MD1, Michael Lee1, Parviz Dolati, MD1, Corina Tiruta, MSc1, Chad Ball, MD1, William Morrish, MD1, Alim Mitha, MD, MSc1, Andrew Kirkpatrick, MD1, John Wong, MD, MSC11Calgary, Canada Keywords: computed tomography, stroke, angiography, trauma, vascular
Early detection of blunt cerebrovascular injury (BCVI) after trauma may prevent potentially life-threatening stroke.
This study investigates the utility of a consensus-based BCVI screening protocol with computed tomographic angiography (CTA) at a level-one trauma centre.
Out of 5342 trauma patients, 47 (0.9%) had cranial or cervical artery dissections, the majority of which were extracranial in location (89%). Their mean age was 38 years and 60% were male. Nineteen patients (40%) had carotid dissections, 27 (57%) had vertebral dissections, and 1 (2%) had both.
After local multi-disciplinary review, a BCVI screening protocol was developed and implemented on August 1, 2005. It is composed of 5 major criteria indicating the recommendation for CTA in trauma patients: 1) severe mechanism associated with facial fracture or diffuse axonal brain injury; 2) near hanging with anoxic brain injury; 3) physical signs suggestive of serious neck trauma (i.e. seat belt abrasion); 4) significant basal skull fracture and 5) cervical fracture affecting the vertebral body or extending into the foramen transversarium. Patients from 2002 to 2008 were identified using a prospective registry containing trauma patients with an injury severity score (ISS) of at least 12, and screened for BCVI over two 3-year epochs (before and after the screening CTA protocol implementation) via retrospective hospital chart review. The BCVI detection rate, stroke rate, and mean modified Rankin scale (mRS) at hospital discharge were compared before and after protocol implementation using the Fisher exact test and Mann-Whitney U-test.
Comparing time periods before versus after protocol implementation, the number of patients with arterial dissections was nearly the same (23 versus 24, respectively) but those undergoing vascular imaging tests increased substantially (129 versus 245, respectively). Prior to protocol implementation, 57% of BCVI patients (13/23) suffered an ischemic stroke, but afterwards the stroke rate was lower at 29% (7/24, p=0.08). All seven of these latter patients had met screening CTA criteria but three did not actually undergo CTA until later prompted by clinical symptoms. BCVI management included conservative observation in 10 patients, antiplatelet and/or anticoagulation therapy in 34, endovascular intervention in 2, and open neurosurgery in 2. Mean mRS at hospital discharge before and after the protocol implementation was the same (mRS 2.9, p=0.90).
This is a retrospective study.
In our level-one trauma centre, a CTA screening protocol for BCVI was effective in detecting early cranial and cervical arterial dissections and was associated with reduction in ischemic stroke rates.
Cooperative multi-centre studies are suggested to corroborate this finding. Project Roles:
M. Tso (), M. Lee (), P. Dolati (), C. Tiruta (), C. Ball (), W. Morrish (), A. Mitha (), A. Kirkpatrick (), J. Wong ()