Department of Bioengineering, George Mason University, 4400 University Dr, MS 1G5, Fairfax, VA 22030 USA.
J Ultrasound Med. 2013 Oct;32(10):1759-68. doi: 10.7863/ultra.32.10.1759.
Blunt cervical vascular injuries, often missed with current screening methods, have substantial morbidity and mortality, and there is a need for improved screening. Elucidation of cerebral hemodynamic alterations may facilitate serial bedside monitoring and improved management. Thus, the objective of this study was to define cerebral flow alterations associated with single blunt cervical vascular injuries using transcranial Doppler sonography and subsequent Doppler waveform analyses in a trauma population.
In this prospective pilot study, patients with suspected blunt cervical vascular injuries had diagnoses by computed tomographic angiography and were examined using transcranial Doppler sonography to define cerebral hemodynamics. Multiple vessel injuries were excluded for this analysis, as the focus was to identify hemodynamic alterations from isolated injuries. The inverse damping factor characterized altered extracranial flow patterns; middle cerebral artery flow velocities, the pulsatility index, and their asymmetries characterized altered intracranial flow patterns.
Twenty-three trauma patients were evaluated: 4 with single internal carotid artery injuries, 5 with single vertebral artery injuries, and 14 without blunt cervical vascular injuries. All internal carotid artery injuries showed a reduced inverse damping factor in the internal carotid artery and dampened ipsilateral mean flow and peak systolic velocities in the middle cerebral artery. Vertebral artery injuries produced asymmetry of a similar magnitude in the middle cerebral artery mean flow velocity with end-diastolic velocity alterations.
These data indicate that extracranial and intracranial hemodynamic alterations occur with internal carotid artery and vertebral artery blunt cervical vascular injuries and can be quantified in the acute injury phase by transcranial Doppler indices. Further study is required to elucidate cerebral flow changes resulting from a single blunt cervical vascular injury, which may guide future management to preserve cerebral perfusion after trauma.
目前的筛查方法常漏诊钝性颈部血管损伤,此类损伤发病率和死亡率高,因此需要改进筛查方法。阐明脑血流动力学改变有助于连续进行床边监测和改善管理。因此,本研究的目的是使用经颅多普勒超声(TCD)在创伤人群中定义与单一钝性颈部血管损伤相关的脑血流改变,并对随后的多普勒波形进行分析。
在这项前瞻性初步研究中,疑似钝性颈部血管损伤的患者进行了计算机断层血管造影(CTA)检查,并使用 TCD 超声检查来定义脑血流动力学。排除了多支血管损伤,因为本分析的重点是识别孤立性损伤的血流动力学改变。反向阻尼因子可用于描述颅外血流模式改变;大脑中动脉血流速度、搏动指数及其不对称性可用于描述颅内血流模式改变。
共评估了 23 例创伤患者:4 例为单一颈内动脉损伤,5 例为单一椎动脉损伤,14 例无钝性颈部血管损伤。所有颈内动脉损伤患者的颈内动脉反向阻尼因子降低,大脑中动脉的平均血流和收缩期峰值速度均减弱。椎动脉损伤导致大脑中动脉平均血流速度的不对称性相似,并伴有舒张末期速度改变。
这些数据表明,颈内动脉和椎动脉钝性颈部血管损伤会导致颅外和颅内血流动力学改变,TCD 指数可在急性损伤阶段对其进行量化。需要进一步研究以阐明单一钝性颈部血管损伤引起的脑血流变化,这可能有助于指导创伤后保护脑灌注的未来管理。