Bilateral Blunt Traumatic Dissections of the Extracranial Internal Carotid Artery: A Case Report and Literature Review

Bilateral traumatic dissections of the cervical internal carotid artery (ICA) are rare complications of polytrauma. A thorough literature review was performed, and data from selected studies were analyzed to assess the trends in clinical presentation, modes of trauma, management protocols, and clinical outcomes. The reported outcomes were categorized and graded into optimal, intermediate, and poor outcomes. We describe a rare case of bilateral dissection of ICA in a 31-year-old woman who was involved in a motor vehicle accident. She had a Glasgow Coma Scale score of 9 and right-sided hemiparesis. Radiological findings revealed left upper ICA dissection, arterial intramural thrombus, and stenosis of the upper segment of the right ICA. She improved on conservative management and had a good clinical outcome at a three-month follow-up. Emergency physicians must be knowledgeable about such cases, as more than half of these trauma victims are initially asymptomatic on initial presentation. Specific diagnostic and therapeutic modalities should be implemented based on low threshold clinical suspicion to avoid missing these potentially disabling injuries and reduce morbidity and mortality. Computed tomographic angiography is recommended in cases with atypical clinical presentations, unexplained neurological deficits, or delayed-onset clinical deterioration. While antiplatelet and anticoagulant therapies are the mainstays of conservative management, endovascular and surgical management are only used in severe cases when medical treatment has failed, the artery has been completely transected, or there is active bleeding. Generally, good outcomes were reported in about two-thirds of those patients.


Introduction
Carotid artery dissection is a relatively rare condition, as the prevalence is between 2.5 and three per 100,000/year [1].The segment of the internal carotid artery (ICA), which is located between the bifurcation of the common carotid artery and the base of the skull, is referred to as the cervical ICA [2].Even though the ICA's location places it at a significant risk for injury due to its mobility and susceptibility to stretching, the majority of carotid artery dissections occur spontaneously, and only 4% of the reported dissections of the ICA are related to severe trauma [3,4].The most common type of trauma is blunt trauma, which is typically caused by accidents involving motor vehicles and can disrupt one or more of the layers of the ICA [5,6].Research studies have demonstrated that almost 1% to 2% of patients who suffered blunt trauma had extracranial traumatic vascular injuries, while the incidence of ICA injuries was between 0.08% and 0.33%.However, fortunately, 52%-79% of these injuries did not manifest any symptoms [7,8].
In most patients with ICA dissection, conservative medical treatment is sufficient for effective management [9].However, on the other hand, endovascular and surgical interventions are required in a relatively small percentage of cases.The diagnosis of traumatic dissection of the ICA is frequently challenging and may be delayed because the presenting symptoms may be overlooked in the initial clinical assessment, particularly in the presence of other injuries [3].Blunt bilateral traumatic dissections of the ICA are a very uncommon entity, as evidenced by the limited number of published case reports and series in the medical literature.However, highlighting such injuries is essential to improving the awareness of clinicians and the involved healthcare team, as it can effectively aid in increasing the suspicion index for diagnostic and treatment strategies, which in turn can reduce the associated morbidity and mortality of trauma patients.We report a rare case of bilateral dissection of ICA in a 31-year-old woman.Additionally, we compare the findings of our reported case with those of the 40 patients who were reported in 26 different papers in the literature to signify the importance of such injuries in terms of presentation, diagnosis, and management .These studies from the literature were retrieved after conducting an intensive review and analysis of the available literature.A 31-year-old woman was involved in a motor vehicle collision and was referred to our facility by a nearby hospital 24 hours after the incident.The patient's medical history was unremarkable, and she did not take any regular medications.On arrival, her vital signs were stable, and she had a Glasgow Coma Scale (GCS) score of 9/15.She was localizing to pain, opening her eyes in response to speech, and demonstrating no verbal response.She had grade 3 right-sided hemiparesis on the Medical Research Council scale for motor power.Cranial nerves were grossly intact.In addition, distal arterial pulsations were normal, and there were no signs of arterial ischemia in any of the extremities.Due to the patient's atypical presentation and unexplained neurological deficits, we proceeded from plain brain computed tomography (CT) to CT angiography, magnetic resonance imaging, and magnetic resonance arteriography.The images revealed left upper ICA dissection, arterial intramural thrombus, and stenosis of the upper segment of the right ICA.The skeletal examination revealed stable sacral and pubic rami fractures, and the abdomen CT scan revealed a low-grade liver injury (Figures 1A, 1B   Antiplatelet therapy with aspirin 81 mg once daily and therapeutic subcutaneous doses of enoxaparin 6,000 IU twice daily for three months was initiated.Liver injury and fractures of the sacral and pubic rami were treated conservatively without complications.The patient's condition gradually improved under conservative care until she became fully awake, conscious, and verbally responsive.Both aphasia and rightsided hemiparesis improved gradually.She was discharged two weeks following admission.Before discharge, follow-up CT angiography revealed the disappearance of filling defects in the left internal artery and the persistence of stenosis in the upper right ICA (Figure 3).On a three-month follow-up, the patient showed no residual neurological deficits.

Discussion
The majority of ICA dissections are spontaneous [3]; however, there is limited clinical data on ICA dissections caused by trauma.Moreover, the bilateral occurrence of traumatic ICA dissections is exceedingly uncommon, and our current case is therefore regarded as an important addition to the current literature on this rare vascular disorder [37].Our comprehensive review yielded information including clinical presentation, diagnosis, management strategies, and clinical outcomes.
While studying age and gender distribution among our study cases, we identified that four patients were under the age of 18 at the time of injury, 29 patients were between the ages of 18 and 40, and seven patients were older than 40 years.The average age of the patients studied was 31 years.Twenty-three of the patients in the study were female.Cranial nerve palsies, alone or in combination, were observed in 12 patients.The cranial nerve palsies most frequently reported were facial nerve palsy (nine patients), oculomotor nerve palsy (two patients), and glossopharyngeal nerve palsy (one patient).
Motor vehicle accidents were the leading cause of injury in almost 80% of 32 cases.Other causes reported of trauma were domestic violence (7.5%) and one case each of horse kicks, falling from a height, neck strangulation injury, chiropractic manipulation, and a private aircraft accident.Cronlein et al. reported that the sudden deceleration of motor vehicles is likely the cause of traumatic ICA dissections in restrained passengers [21].While activation of the coagulation cascade, cerebral arterial dissection increases the risk of developing a thrombus as well as cerebral thromboembolism and ischemia [3,38,39].The clinical presentation of observed cases was marked by substantial variation and discordance from being asymptomatic, having early neurological deficits, or having a clinical presentation with a delayed onset.
The group of asymptomatic patients, however, is quite challenging and is frequently identified by accident or overlooked.Patients typically exhibit no neurological deficits.Findings from our review of the literature revealed that almost 55% (22 patients) were initially asymptomatic, and among them, 17 were aged between 18 and 40 years.In seven asymptomatic patients, symptoms started between six and 12 hours; in nine patients, symptoms started between one and seven days; and in five patients, symptoms started one to six months following trauma.One patient had a delayed onset of symptoms, but the duration was not specified.
In the group of patients who presented with early symptoms, there were 18 patients (45%) with immediate post-traumatic symptoms or impairments.Hemiparesis (n = 15), pupillary changes, visual field cuts, cranial nerve palsies (n = 15), aphasia (n = 10), and coma (n = 4) were among the presenting symptoms.Headache, dizziness, neck pain, amaurosis fugax, pronator drift, hemi-hypoesthesia, Horner's syndrome, and incoordination were also reported as less frequent manifestations.The initial and delayed presentation of cases is demonstrated in Table 1.

Case
No.

TABLE 1: Initial and delayed presentation of cases
There are numerous diagnostic imaging modalities for assessing vessel dissection [21].CT scans and CT angiography are primarily used to diagnose cerebral vascular pathologies in emergencies.String signs, lupus constrictions, and arterial hypertension are regarded as indirect indicators of an artery dissection [38].In the reported cases, various diagnostic techniques were utilized to confirm the diagnosis.In 17 cases, carotid angiography was the most frequently used imaging modality, followed by CT angiography in 15 cases (Table 2).Anticoagulants and antiplatelet medications were used to treat most patients [3,40], eight underwent endovascular procedures, and three underwent surgery after medical treatment failed (Tables 3, 4).Cerebrovascular dissections can be treated with open surgical methods like microvascular suturing, extracranial-intracranial bypass, and thromboendarterectomy, or endovascular methods like stenting, stentassisted intravascular thrombolysis, and thrombectomy [3,38].Surgical and endovascular alternatives are used in the most severe and critical clinical situations [40], in cases with complete arterial transactions, and after medical treatment fails [41].

TABLE 4: Management details and clinical outcomes of 40 patients in the reviewed articles
We reviewed the available literature and classified the reported clinical outcomes as good outcomes when there had been complete recovery or only mild neurological deficits, intermediate outcomes when there was hemiparesis, and poor outcomes when there were severe permanent deficits or death.Overall, among all 40 patients assessed, optimal, intermediate, and poor outcomes were observed in 25, eight, and seven patients, respectively, and in total, seven mortalities were noted (Table 4).Among 22 initially asymptomatic patients, optimal, intermediate, and poor outcomes were reported in 14, five, and three patients, respectively.In this group, one mortality was observed.On the other hand, among 18 initially symptomatic patients, optimal, intermediate, and poor outcomes were encountered in 11, three and four patients, respectively, and in this cohort, four mortalities were reported.In our case, we observed optimal clinical and radiological outcomes.

Conclusions
Bilateral traumatic dissections of the extracranial cervical ICA occur in polytraumatized patients, and more than half of these cases are initially asymptomatic on initial presentation.Specific diagnostic and therapeutic modalities should be implemented based on low threshold clinical suspicion in order to avoid missing these potentially disabling injuries and reduce morbidity and mortality.CT angiography is recommended in cases with atypical clinical presentations, unexplained neurological deficits, or delayedonset clinical deterioration.Antiplatelet and anticoagulant therapies are the mainstays of conservative management.Endovascular and surgical management are only used in severe cases when medical treatment has failed, the artery has been completely transected, or there is active bleeding.Generally, optimal outcomes were reported in about two-thirds of those patients.A multidisciplinary management approach is mandatory in this rare type of injury.

FIGURE 1 :
FIGURE 1: (A, B) Initial post-traumatic axial computed tomography of the brain showing multiple bilateral hemispheric hypodense area multiple strokes (red circle).

FIGURE 2 :
FIGURE 2: Initial coronal computed tomography angiogram of the neck showing left upper cervical ICA dissection (red arrow) and evidence of arterial intramural thrombus, in addition to stenosis of the upper segment of right ICA (blue arrow) R: right side; L: left side; ICA: internal carotid artery

FIGURE 3 :
FIGURE 3: A follow-up coronal computed tomography angiogram of the neck showing normal left internal carotid artery (red arrow) and mild residual right internal carotid stenosis (blue arrow).R: right; L: left

TABLE 2 : Neurovascular imaging findings in the reviewed articles
DSA: Digital Subtraction Angiography; CT: Computed tomography; MRA: Magnetic resonance angiography; ICA: Internal carotid artery