Vascular Injuries to the Neck After Penetrating Trauma: Diagnostic Performance of 40- and 64-MDCT Angiography

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1 Neuroradiology/Head and Neck Imaging Original Research Neuroradiology/Head and Neck Imaging Original Research Uttam K. odanapally 1 David Dreizin 1 Clint W. Sliker 1 lexis R. oscak 1 Ramachandra P. Reddy 2 odanapally UK, Dreizin D, Sliker CW, oscak R, Reddy RP Keywords: CT angiography, digital subtraction angiography, neck, penetrating trauma, vascular injuries DOI: /JR Received November 22, 2014; accepted after revision March 28, Department of Radiology, R. dams Cowley Shock Trauma Center, University of Maryland Medical Center, 22 S Greene St, altimore, MD ddress correspondence to U. K. odanapally (ubodanapally@umm.edu). 2 lbert Einstein College of Medicine of Yeshiva University, ronx, NY. Supplemental Data vailable online at JR 2015; 205: X/15/ merican Roentgen Ray Society Vascular Injuries to the Neck fter Penetrating Trauma: Diagnostic Performance of 40- and 64-MDCT ngiography OJECTIVE. The purposes of this study were to assess the diagnostic performance of 40- and 64-MDCT angiography with digital subtraction angiography as the reference standard in the detection of arterial injuries in patients at high risk after penetrating neck trauma and to perform a separate analysis of injuries to the external carotid artery. MTERILS ND METHODS. In a retrospective evaluation of 53 sets of angiograms from 51 patients with penetrating neck injury, three reviewers unaware of the digital subtraction angiographic findings reviewed the CT angiographic (CT) images to discern the presence or absence of arterial injuries. Sensitivity and specificity of CT were calculated per injury, and a separate analysis of external carotid artery injuries was performed. RESULTS. Sensitivity of CT for detecting arterial injuries ranged from 75.7% (95% CI, %) to 82.2% (95% CI, %). Specificity ranged from 96.4% (95% CI, %) to 98.4% (95% CI, %). CT was highly sensitive for detection of the subgroup of injuries involving the large-caliber vessels that contribute to cerebral circulation. These sensitivities ranged from 92.8% (95% CI, %) to 100% (95% CI, %) for internal carotid artery injuries and from 88.9% (95% CI, %) to 94.4% (95% CI, %) for vertebral artery injuries. In contrast, sensitivity of CT was limited for external carotid artery injuries, ranging from 63.4% (95% CI, %) to 70.0% (95% CI, %). CONCLUSION. CT can be used for initial evaluation and may help guide management decisions if an external carotid artery injury is detected. Negative findings should not preclude close clinical follow-up, repeat CT evaluation, or, in the presence of high suspicion of arterial injury due to clinical findings or wound trajectory, evaluation with digital subtraction angiography. rterial injuries are common after penetrating neck trauma, having a reported incidence of 15 20% [1 3]. Injuries to the vessels that contribute to cerebral circulation can be devastating and have the potential to cause cerebral infarction and death [1, 4, 5]. lthough penetrating injuries to the internal carotid artery (IC) and vertebral artery are more common, the external carotid artery (EC) and its branches are often injured, which can increase morbidity [6 8]. There is little literature regarding EC injuries, perhaps because of the lower incidence and the fewer devastating neurologic complications than for IC and vertebral artery injuries. The introduction of 40- and 64-MDCT helical CT scanners has greatly advanced the role of CT angiography (CT) in neurovascular imaging. Isotropic datasets can be rap- idly acquired, allowing image reconstruction in various planes with superior spatial resolution and potentially improving the accuracy of CT in detecting vascular injuries. Most of the previous studies regarding the diagnostic accuracy of CT in helping to detect penetrating arterial injuries to the neck have included surgical findings and clinical follow-up as the reference standards [9 14]. The limitation of using surgical findings and clinical follow-up as reference standards is the low sensitivity for detection of asymptomatic vascular injuries [11]. The only major study with a head-to-head comparison of CT and digital subtraction angiography (DS) [14] was performed with a single-detector helical CT scanner and a total of 10 injuries in 60 patients. Moreover, the report of that study did not cite the ability of CT to depict penetrating EC injuries. 866 JR:205, October 2015

2 The purpose of our study was to determine, using DS as the reference standard, the diagnostic performance of 40 and 64-MDCT angiography for detecting arterial injuries in patients at high risk with a large number of injuries and to perform a separate analysis of EC injuries after penetrating neck trauma. Materials and Methods This retrospective study was compliant with HIP and was conducted at an urban level I trauma center. Permission was obtained from our institutional review board, which provided a waiver of informed consent. Study Population We searched the trauma registry at our institution to identify all patients who presented with penetrating neck trauma between January 1, 2008, and December 31, The inclusion criteria were history of penetrating trauma to the neck, defined by entry wound below the base of the skull and above the clavicles and sternal notch; performance of both CT and DS within 24 hours of each other; and patient age 18 years or older. There were 236 penetrating neck trauma patients with CT performed at admission; 51 of them met the inclusion criteria. mong the 51 patients, 30 patients underwent CT and had findings prospectively interpreted as positive owing to identification of at least one arterial injury in the neck vessels. t the study institution, all CT examinations with positive findings were followed either by DS with possible treatment by endovascular means or by repeat CT to evaluate the evolution of injuries. The decision regarding the mode of the follow-up evaluation is usually made at the discretion of the trauma surgeons. The other 21 patients had CT findings interpreted as negative. However, these patients underwent DS for various reasons: trajectory of the wound close to the arteries or streak artifacts from bullet fragments, nine patients; uncontrolled active bleeding from the wound in the oral or nasal cavities, four; bleeding from the neck wound, three; hemorrhagic shock after local exploration and ligation of anterior jugular vein, one; large neck hematoma, two; pseudoaneurysm of thyrocervical trunk, one; and concurrent intracranial trajectory (for which the protocol mandates DS), one patient. DS of patients with a wound trajectory close to the arteries was performed at the discretion of the attending surgeons according to their comfort level and clinical status of the patient. There were 187 patients excluded from the study: 181 patients without accompanying DS and six patients who underwent DS more than 24 hours after CT. mong the 51 selected patients (44 men, seven women; mean age, 33 years; range, years), the mechanism of injury was gunshot wound in 37 patients and stab wound in 14. The mean interval between CT and DS was 8 hours 50 minutes (range, 1 hour 45 minutes 19 hours 30 minutes). For all patients, CT was performed before DS. total of 53 sets of studies of 51 patients were included in the study. In total, 768 vessels were analyzed in the 53 angiographic sets included in the study. In the case of 44 sets from 44 patients, CT was performed immediately after initial resuscitation in the trauma admission unit. Seven patients underwent admission CT and did not undergo DS within 24 hours. For these patients, follow-up sets were included in the study (second CT and accompanying DS during the course of hospitalization). The follow-up study sets were obtained from day 3 to day 35 after admission. Most were obtained by day 5 (four studies performed on day 3, one on day 4, two on day 5, one on day 6, two on day 14, and one on day 35). In two patients, both admission sets and one follow-up set were included in the study for review. The follow-up images of these two patients were included because each had either development of a new vascular lesion or evolution of a known injury compared with that on the initial image set. Eleven patients had transcervical injuries or multiple injuries involving both sides of the neck, and arteries from both sides were included in the analysis. Figure 1 shows the patient selection flowchart. Patients with CT and DS performed within 24 hours of each other: 51 dmission and follow-up study sets included: 2 Total number of study sets included: 53 Patients with penetrating neck trauma with CT: 236 Patients without DS: 181 Reference Standard The reference standard for arterial injury in each study set was the final reported interpretation of the DS images. The reports were further confirmed by direct review of the images. MDCT Protocol ll patients underwent CT according to our institutional protocol with either a 40- or a 64-MDCT unit (rilliance, Philips Healthcare). Twenty CT examinations were performed with a 40-MDCT unit and 33 with a 64-MDCT unit. To determine scan delay, a test bolus of 20 ml of iohexol at 350 mg I/mL (Omnipaque 350, GE Healthcare) was injected at a rate of 4 ml/s followed by a 50-mL saline flush at 4 ml/s. Imaging parameters were as follows: pitch, 0.671; section thickness, 1 mm; interval, 0.5 mm; collimation, 0.625; reconstruction interval, 2-mm thickness at 1-mm intervals; tube voltage, 120 kv; tube current 350 m. The scan coverage extended from vertex to aortic arch. fter scan delay was determined, 80 ml of iohexol was injected at a rate of 4 ml/s through a power injector and followed by a 50-mL saline flush at 4 ml/s. The source images were reformatted into sagittal and coronal maximum intensity projections (5-mm thickness at 2-mm intervals) and sagittal and coronal multiplanar reconstructions (2-mm thickness at 1-mm intervals). ll CT data were transferred to a standard workstation for postprocessing. ll neck DS examinations were performed by fellowship-trained interventional neuroradiologists with certificates of added qualification. Standard images were obtained in at least two orthogonal planes (typically anteroposterior and lateral); additional images were obtained at the discretion of each neuroradiologist according to his or her CT and DS performed beyond 24 hours: 6 Fig. 1 Flowchart shows patient selection results. CT = CT angiography, DS = digital subtraction angiography. JR:205, October

3 preference, the patient s clinical condition, and the anatomy of the injured vessel. Complete four-vessel angiograms were not universally obtained, and the vessels studied were at the discretion of the attending neuroradiologist on the basis of the trajectory of the penetrating wound and the clinical manifestations. Only vessels evaluated with DS were included for analysis. Image Interpretation Three attending radiologists blinded to the DS findings independently reviewed all of the CT images. The radiologists had varying levels of experience (reviewer 1, 1 year; reviewer 2, 8 years; reviewer 3, 14 years). For each patient, all images were loaded to a dedicated study worklist on our institution s PCS (GF Impax, GF Healthcare) after the removal of the personal identifying information by an author not participating in subsequent image interpretation. ll the cases were randomized and assigned for review among the radiologists. Standard workstations configured with thin-client postprocessing software were used. For localization purposes, the neck arteries were divided into individual branch vessels that were analyzed and reported on separately: common carotid artery (CC), IC, vertebral artery, and EC. The EC was further subdivided into the EC main trunk and the following branches: superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, internal maxillary, and superficial temporal arteries. The reviewers assigned each arterial branch and segment a nominal score based on the presence or absence of injury. To help assess individual branches of the EC, the reviewers were given a hard copy containing multiple axial CT images of the neck at various levels with each branch labeled. Once an injury was identified, it was characterized into one of the six predetermined types of arterial trauma that included pseudoaneurysm (Fig. 2), dissection (Fig. 2), occlusion, arteriovenous fistula (VF) (Figs. 3 and 4), active bleeding, and vasospasm. The streak artifacts from the bullet fragments that limited evaluation of partial or complete segments of the vessels were independently rated as nonevaluable by the individual reviewers. Statistical nalysis To evaluate the diagnostic performance of CT in the detection of arterial injuries, we performed individual vessel level analysis. The overall evaluability (ratio of the number of evaluable vessels to all vessels), sensitivity, and specificity were calculated from chi-square tests of contingency, and 95% CIs were calculated with the ratio estimator of variance for individual vessel level analysis. The nonevaluable vessels were dealt with by pairwise deletion for this univariate analysis. In a second analysis, all of the nonevaluable vessels were rated as positive, reflecting the intention-to-diagnose aspect of the study. The interobserver variability among three independent observers for the detection of arterial injuries was assessed with the Cohen kappa statistic. Contingency tables were generated with statistical software (JMP 11, SS Institute), and CIs were adjusted with the calculation ratio estimator in SS software (version 9.3, SS Institute). Results In the 51-patient cohort, 39 patients had arterial injuries consisting of 76 different vessel injuries. There were 10 pseudoaneurysms (CC, two; IC, two; vertebral artery, two; EC, four), five pseudoaneurysms with active bleeding (all EC injuries), six pseudoaneurysms with VF (IC, two; vertebral artery, three; EC, one), 31 arterial occlusions (IC, six; vertebral artery, seven; EC, 18), one occlusion with VF involving the vertebral artery, three VFs (vertebral artery, one; and EC, two), eight dissections (IC, two; vertebral artery, three; EC, three), eight cases of active bleeding (all injuries involving the EC), and four cases of arterial spasm (IC, two; vertebral artery, one; EC, one). The type and distribution of the 76 vessel injuries are shown in Table S1. (Tables S1 and S2, supplemental data, can be viewed in the JR electronic supplement to this article, available at Fifteen of the 39 patients had more than one vessel injury. Two patients had the maximum of five different vessel injuries. Diagnostic Performance of CT ngiography for ll rterial Injuries Overall sensitivities and specificities of CT in the detection of vascular injuries are shown for each reviewer in Table 1. mong the total 768 vessels analyzed, reviewer 1 rated 27 vessels nonevaluable; reviewer 2, 26 vessels; and reviewer 3, 25 vessels ( 3%). They rated two, three, and two vessel injuries obscured by metal artifacts from bullet fragments, which made them nonevaluable. The overall sensitivities ranged from 75.7% (95% CI, ) to 82.2% (95% CI, ); specificities ranged from 96.4% (95% CI, %) to 98.4% (95% CI, ). The individual sensitivities and specificities for the three individual reviewers are shown in Table 1. ll types of injuries with true-positive and false-positive readings by the reviewers are shown in Table S2. TLE 1: Diagnostic Performance of CT ngiography for rterial Injuries ased on Individual Vessel Level nalysis Vessel Reviewer 1 Reviewer 2 Reviewer 3 Sensitivity (%) Specificity (%) Sensitivity (%) Specificity (%) Sensitivity (%) Specificity (%) Common carotid artery 100 (1/1) [ ] 100 (57/57) [ ] 100 (1/1) [ ] 100 (57/57) [ ] 100 (1/1) [ ] 100 (57/57) [ ] Internal carotid artery 100 (14/14) [ ] 85.7 (42/49) [ ] 100 (14/14) [ ] 91.8 (45/49) [ ] 92.8 (13/14) [ ] External carotid artery branches 68.3 (28/41) [ ] 97.3 (507/521) [ ] 70.0 (28/40) [52 85] 97.5 (510/523) [ ] 63.4 (26/41) [ ] Vertebral artery 88.9 (16/18) [ ] 92.5 (37/40) [ ] 94.4 (17/18) [ ] 97.5 (39/40) [ ] 88.9 (16/18) [ ] ll 79.7 (59/74) [ ] 96.4 (643/667) [ ] ll (nonevaluable branches as positive) 82.2 (60/73) [ ] 97.3 (651/669) [95 99] 75.7 (56/74) [ ] 80.3 (61/76) [ ] 92.9 (643/692) [ ] 82.9 (63/76) [ ] 94.2 (651/691) [ ] Note Values in parentheses are numbers of patients. Values in square brackets are 95% CI (58/76) [ ] 91.8 (45/49) [ ] 98.8 (517/523) [ ] 97.5 (39/40) [ ] 98.4 (658/669) [ ] 95 (658/692) [ ] 868 JR:205, October 2015

4 When all the nonevaluable vessels were rated as positive, the overall sensitivities ranged from 76.3% (95% CI, %) to 82.9% (95% CI, %), and specificities ranged from 92.9% (95% CI, %) to 95% (95% CI, %). greement among the three reviewers was either substantial or almost perfect (range, ). Diagnostic Performance of CT ngiography for External Carotid rtery Injuries and Their Treatment The sensitivities for EC injuries ranged from 63.4% (95% CI, %) to 70% (95% CI 52 85), and the specificities from 97.3% (95% CI, %) to 98.8% Fig year-old man with gunshot injury to face., xial CT angiogram (CT) at admission shows irregularity of right lingual artery (arrowhead) described as dissection., Follow-up CT obtained on day 12 after initial injury because of bleeding from mouth shows interval development of giant pseudoaneurysm (arrowhead). C, Sagittal digital subtraction angiogram obtained after selective cannulation of right lingual artery shows pseudoaneurysm. (95% CI, %). mong the 42 EC branch injuries, the most common form of injury was complete arterial occlusion (18 vessels), followed by pseudoaneurysm (10 vessels) and active bleeding (eight vessels). Nine of the 10 pseudoaneurysms involving the EC branches in our cohort were treated with endovascular embolization. The one untreated pseudoaneurysm, involving the main trunk of the EC, had no evidence of clinical progression during follow-up physical examination 75 days after the initial injury. ll eight vessels with active bleeding were embolized. Of the two isolated VFs, the untreated small ascending pharyngeodural venous fistula was followed by means of repeat angiography, which did not reveal evidence of progression. Of the combined 21 vessel occlusions and dissections, none was treated by endovascular means. Followup of these patients by physical examination or repeat CT showed injury evolution with pseudoaneurysm formation in three patients. Two of the pseudoaneurysms evolved from vessel occlusions. The manifestation was recanalization of the lumen with pseudoaneurysm formation one arising from the internal maxillary artery and one from the occipital artery. The third pseudoaneurysm evolved from the lingual artery and at initial examination manifested itself as dissection with luminal irregularity (Fig. 2). ll three Fig year-old man with stab injury to neck., CT angiogram (CT) of neck obtained at admission shows pseudoaneurysm (arrowhead) arising from left occipital artery., Digital subtraction angiogram obtained 3 hours after CT shows large pseudoaneurysm (arrowhead) and arteriovenous fistula (curved arrow) with internal jugular vein. lso evident is contrast-opacified internal jugular vein (straight arrow). C JR:205, October

5 pseudoaneurysms were later embolized by endovascular means. Discussion The options available to identify arterial injuries in the neck after penetrating trauma include CT and DS. DS is expensive, labor-intensive, and sometimes difficult to perform in a timely manner at centers where equipment or qualified personnel are limited. Hence, it is not an optimal choice as a screening modality [15]. t many centers, CT has essentially replaced DS for the initial evaluation of patients with penetrating neck injury. When we used CT to identify penetrating arterial injuries to the neck, we found it to have an overall sensitivity ranging from 75.7% (95% CI, %) to 82.2% (95% CI, %). When EC branches were excluded, CT was highly sensitive for detecting the subgroup of injuries involving the vessels that contribute to cerebral circulation. Sensitivities ranged from 92.8% (95% CI, %) to 100% (95% CI, %) for IC injuries and from 88.9% Fig year-old man with transcervical gunshot injury to neck., Coronal maximum intensity projection CT angiogram shows right internal carotid artery pseudoaneurysm (curved arrow) and arteriovenous fistula (arrowhead) with internal jugular vein (straight arrow)., Digital subtraction angiogram shows right internal carotid artery pseudoaneurysm (curved arrow) and arteriovenous fistula (arrowhead) with early internal jugular vein opacification (straight arrow). (95% CI, %) to 94.4% (95% CI, %) for vertebral artery injuries. In contrast, the sensitivity of CT was limited with respect to EC injuries, ranging from 63.4% (95% CI, %) to 70.0% (95% CI, %). Unlike CC, IC, and vertebral artery injuries, EC injuries are not associated with devastating neurologic complications. Nevertheless, they are important because they can cause airway compromise and exsanguination resulting from either acute uncontrolled bleeding or delayed rupture of a pseudoaneurysm (Fig. 2). Several studies [9 13] have shown greater than 90% sensitivity of CT with an aggregate of conventional angiography, surgical findings, and clinical follow-up as reference standards. The limitation of using physical examination and clinical follow-up as reference standards is the low sensitivity for detection of asymptomatic vascular injuries [11, 16]. Hence, the absence of overt clinical signs or symptoms of a clinically significant vascular injury does not mean that the injury is not present. Frequencies of missed vascular injuries ranging from 23% to as high as 43% have been reported [17 20]. Múnera et al. [14] evaluated 60 patients with penetrating neck trauma with both single-detector CT and DS. They identified 10 injuries involving the CC, IC, or vertebral artery and reported CT to have sensitivity of 90% and specificity of 100%. They did not report on EC injuries. To our knowledge, the only study of the use of 40- or 64-MDCT angiography to diagnose penetrating arterial injuries was by Inaba et al. [13]. Those authors prospectively evaluated 453 patients with five CC, two IC, two vertebral artery, and four EC injuries. Using surgical exploration, DS, and clinical follow-up as reference standards, they found sensitivity of 100% and specificity of 97.5%. Compared with the previous studies, our study showed similar high sensitivity of CT for the large-caliber arteries (CC, IC, and vertebral arteries) that contribute to the cerebral circulation. However, the major limitation of CT seems to be limited sensitivity for detecting injuries to small-caliber arteries, such as the EC and its branches. similar limitation of CT in detecting penetrating intracranial arterial injuries was identified by [21]. This lower sensitivity can be explained by the fact that the EC branches are considerably smaller in caliber, which may decrease the rate of detection of injuries owing to the lower spatial resolution of CT than of DS. The true incidence of EC injuries after penetrating neck trauma is not well documented. One prospective study that included 223 patients (176 of whom underwent conventional angiography) showed that 13 patients had injury to the EC or its branches [8]. Identifying EC injuries and management with either close clinical follow-up or treatment of the identified injuries is generally considered mandatory because of the dynamic nature of the injuries, which includes a tendency to progress, which can result in exsanguination or airway compromise secondary to arterial rupture. EC injuries reportedly [22] have a tendency to become evident as complete occlusion because their small caliber is a predisposing factor for transection rather than partial laceration with resultant pseudoaneurysm formation. This is supported by our results, which revealed the most common form of injury to be luminal occlusion (18 of 42 patients). In contrast, pseudoaneurysms involving EC branches have been considered rare [23]. However, our data suggest pseudoaneurysms may be 870 JR:205, October 2015

6 C Fig year-old man with gunshot injury to neck., Coronal maximum-intensity-projection CT angiogram shows injury (arrowhead), which two reviewers did not identify prospectively or at retrospective evaluation., Digital subtraction angiogram shows right internal maxillary artery occlusion (arrowhead). C and D, Follow-up CT (C) and digital subtraction (D) angiograms obtained on day 5 after initial injury shows interval development of pseudoaneurysm (arrowhead). D more common than previously reported; approximately 25% of the EC injuries in our study became evident as pseudoaneurysms. lthough some penetrating injuries to EC branches may manifest themselves as occlusion and may not require further intervention, our results show that some occlusions may recanalize and cause a pseudoaneurysm, which carries risk of rupture (Fig. 5). Similarly, dissections not requiring additional intervention and the straightforward treatment strategy of simple vessel occlusion by endovascular means for either pseudoaneurysm or active bleeding, with its reasonably low complication rate, may be the reason for the lesser attention given to EC injuries. There were several limitations to our study. First, it had a retrospective design with inherent biases. Verification bias was unavoidable because all patients selected for the study underwent DS. ecause of the verification bias, our sensitivity estimate may be too high, and specificity may be too low owing to underrepresentation of truenegative cases. However, the verification bias might have been decreased to an extent because of the inclusion of patients without any arterial injuries in the study cohort, performance of individual vessel analysis rather than patient-level analysis, and inclusion in the statistical analysis only of vessels that were evaluated with DS. The use of clinical follow-up as a reference standard has its limitations in a study such as ours, because not all of the missed injuries are clinically apparent at follow-up examinations, making it difficult to rule out an injury. Finally, the time delay between the CT and DS may have resulted in evolutionary changes in the morphologic features of an injury that affected the results. Conclusion CT is sensitive for detecting injuries involving the large-caliber arteries that contribute to the cerebral circulation. However, the sensitivity for detecting EC injuries is limited, presumably owing to the small caliber of the affected vessels. lthough CT can be used for initial evaluation and may help guide management decisions if an EC injury is detected, normal findings do not exclude an injury to an EC branch, because a large number of EC injuries can be missed at CT. Most EC injuries become evident as occlusions, which require no additional treatment should occlusion persist. In some instances, however, occlusive injuries recan- JR:205, October

7 alize and evolve into other types of arterial lesions, including pseudoaneurysms, which have a tendency to rupture and bleed. Hence, negative findings at CT for EC injury should not preclude close clinical follow-up, repeat CT evaluation, or, in the presence of a high index of suspicion for arterial injury based on the clinical findings or wound trajectory, evaluation with DS. References 1. Núñez D Jr, Torres-León M, Múnera F. Vascular injuries of the neck and thoracic inlet: helical CT angiographic correlation. RadioGraphics 2004; 24: ; discussion, sensio J, Valenziano CP, Falcone RE, Grosh JD. Management of penetrating neck injuries: the controversy surrounding zone II injuries. Surg Clin North m 1991; 71: Múnera F, Cohn S, Rivas L. Penetrating injuries of the neck: use of helical computed tomographic angiography. J Trauma 2005; 58: Kuehne JP, Weaver F, Papanicolaou G, Yellin E. Penetrating trauma of the internal carotid artery. rch Surg 1996; 131: ; discussion, Ramadan F, Rutledge R, Oller D, Howell P, aker C, Keagy. Carotid artery trauma: a review of contemporary trauma center experiences. J Vasc Surg 1995; 21:46 55; discussion, Sclafani P, Sclafani SJ. ngiography and transcatheter arterial embolization of vascular injuries of the face and neck. Laryngoscope 1996; 106: Smith TP. Embolization in the external carotid artery. J Vasc Interv Radiol 2006; 17: Demetriades D, Theodorou D, Cornwell E, et al. Evaluation of penetrating injuries of the neck: prospective study of 223 patients. World J Surg 1997; 21: ell R, Osborn T, Dierks EJ, Potter E, Long W. Management of penetrating neck injuries: a new paradigm for civilian trauma. J Oral Maxillofac Surg 2007; 65: Osborn TM, ell R, Qaisi W, Long W. Computed tomographic angiography as an aid to clinical decision making in the selective management of penetrating injuries to the neck: a reduction in the need for operative exploration. J Trauma 2008; 64: Múnera F, Soto J, Palacio DM, et al. Penetrating neck injuries: helical CT angiography for initial evaluation. Radiology 2002; 224: Inaba K, Múnera F Munera F, McKenney M, et al. Prospective evaluation of screening multislice helical computed tomographic angiography in the initial evaluation of penetrating neck injuries. J Trauma 2006; 61: Inaba K, ranco C, Manaker J, et al. Evaluation of multidetector computed tomography for penetrating neck injury: a prospective multicenter study. J Trauma cute Care Surg 2012; 72: Múnera F, Soto J, Palacio D, Velez SM, Medina E. Diagnosis of arterial injuries caused by penetrating trauma to the neck: comparison of helical CT angiography and conventional angiography. Radiology 2000; 216: Sliker CW, Shanmuganathan K, Mirvis SE. Diagnosis of blunt cerebrovascular injuries with 16-MDCT: accuracy of whole-body MDCT compared with neck MDCT angiography. JR 2008; 190: Sclafani SJ, Cavaliere G, tweh N, Duncan O, Scalea T. The role of angiography in penetrating neck trauma. J Trauma 1991; 31: Fogelman MJ, Stewart RD. Penetrating wounds of the neck. m J Surg 1956; 91: ; discussion, pffelstaedt JP, Müller R. Results of mandatory exploration for penetrating neck trauma. World J Surg 1994; 18: ; discussion, ishara R, Pasch R, Douglas DD, Schuler JJ, Lim LT, Flanigan DP. The necessity of mandatory exploration of penetrating zone II neck injuries. Surgery 1986; 100: Steenburg SD, Sliker CW, Shanmuganathan K, Siegel EL. Imaging evaluation of penetrating neck injuries. RadioGraphics 2010; 30: odanapally UK, Shanmuganathan K, oscak R, et al. Vascular complications of penetrating brain injury: comparison of helical CT angiography and conventional angiography. J Neurosurg 2014; 121: Pappa H, Richardson D, Niven S. False aneurysm of the facial artery as complication of sagittal split osteotomy. J Craniomaxillofac Surg 2008; 36: McCollum CH, Wheeler WG, Noon GP, Deakey ME. neurysms of the extracranial carotid artery: twenty-one years experience. m J Surg 1979; 137: FOR YOUR INFORMTION data supplement for this article can be viewed in the online version of the article at: JR:205, October 2015