Vertebral Artery Injury Research Articles

Trauma mechanisms and patterns of blunt cervical vascular injury: A descriptive study using a nationwide trauma registry

ObjectiveBlunt cervical vascular injury (BCVI) is a non-penetrating trauma to the carotid and/or vertebral vessels following a direct injury to the neck or by the shearing of the cervical vessels. Despite its potentially life-threatening nature, important clinical features of BCVI such as typical patterns of co-occurring injuries for each trauma mechanism are not well known. To address this knowledge gap, we described the characteristics of patients with BCVI to identify the pattern of co-occurring injuries by common trauma mechanisms. MethodsThis is a descriptive study using a Japanese nationwide trauma registry from 2004 through 2019. We included patients aged ≥13 years presenting to the emergency department (ED) with BCVI, defined as a blunt trauma to any of the following vessels: common/internal carotid artery, external carotid artery, vertebral artery, external jugular vein, and internal jugular vein. We delineated characteristics of each BCVI classified according to three damaged vessels (common/internal carotid artery, vertebral artery, and others). In addition, we applied network analysis to unravel patterns of co-occurring injuries among patients with BCVI by four common trauma mechanisms (car accident, motorcycle/bicycle accident, simple fall, and fall from a height). ResultsAmong 311,692 patients who visited the ED for blunt trauma, 454 (0.1%) patients had BCVI. Patients with common/internal carotid artery injuries presented to the ED with severe symptoms (e.g., the median Glasgow Coma Scale was 7) and had high in-hospital mortality (45%), while patients with vertebral artery injuries presented with relatively stable vital signs. Network analysis showed that head-vertebral-cervical spine injuries were common across four trauma mechanisms (car accident, motorcycle/bicycle accident, simple fall, and fall from a height), with co-occurring injuries of the cervical spine and vertebral artery being the most common injuries due to falls. In addition, common/internal carotid artery injuries were associated with thoracic and abdominal injuries in patients with car accidents. ConclusionsBased on analyses of a nationwide trauma registry, we found that patients with BCVI had distinct patterns of co-occurring injuries by four trauma mechanisms. Our observations provide an important basis for the initial assessment of blunt trauma and could support the management of BCVI.

Operative V2 decompression for traumatic vertebrobasilar insufficiency: illustrative case.

Blunt vertebral artery injuries after cervical trauma due to the close anatomical relationship of the vertebral artery to the cervical spine may have fatal consequences because of posterior circulation ischemia and vertebrobasilar insufficiency. While the standard of care remains medical treatment by anticoagulation or antiplatelet therapy, surgical decompression of the vertebral artery is rarely indicated. The authors present a case of selective decompression of a traumatically constricted vertebral artery within the transverse foramen of C2 presenting with vertebrobasilar insufficiency due to bilateral aplasia of the posterior communicating arteries and contralateral hypoplasia of the vertebral artery. Because of their close relationship to the cervical spine, the vertebral arteries are at risk for blunt injury, which may present asymptomatically or with symptoms of posterior circulation ischemia or vertebrobasilar insufficiency either immediately or after a latency phase. The anatomical variability of (1) the vertebral arteries, (2) collateral brainstem perfusion, and (3) the individual injury pattern demands individualized treatment strategies. If endovascular treatment of hemodynamically relevant stenosis of the V2 segment of the vertebral artery poses too high a risk for vessel injury, decompression of the transverse foramen can be performed safely and without risk to the biomechanical stability of the cervical spine.

Ultrasonography is an effective tool for the evaluation of traumatic vertebral artery injuries distal to fourth cervical vertebra in the emergency room

BackgroundThis study aimed to determine the feasibility of ultrasonography in the assessment of cervical vertebral artery (VA) injury as an alternative to computed tomography angiography (CTA) in the emergency room.MethodsWe analyzed 50 VAs from 25 consecutive patients with cervical spine injury that had been admitted to our emergency room. Ultrasonography and CTA were performed to assess the VA in patients with cervical spine injury. We examined the sensitivity and specificity of ultrasonography compared with CTA.ResultsAmong these VAs, six were occluded on CTA. The agreement between ultrasonography and CTA was 98% (49/50) with 0.92 Cohen's Kappa index. The sensitivity, specificity, and positive and negative predictive values of ultrasonography were 100%, 97.7%, 85.7%, and 100%, respectively. In one case with hypoplastic VA, the detection of flow in the VA by ultrasonography differed from detection by CTA. Meanwhile, there were two cases in which VAs entered at C5 transverse foramen rather than at C6 level. However, ultrasonography could detect the blood flow in these VAs.ConclusionsUltrasonography had a sensitivity of 100% compared with CTA in assessment of the VA. Ultrasonography can be used as an initial screening test for VA injury in the emergency room.

Robot-Assisted Percutaneous Lag Screw Osteosynthesis for C1 Lateral Mass Fractures: Case Series and Technical Note.

C1 lateral mass fractures (LMF) cause abnormal alignment of the upper cervical joints. Conservatively treated cases can develop into late cock-robin junction, requiring a reconstructive surgical procedure of the occipitocervical junction. Partial coronal C1 LMF could be effectively fixed with lag screws. Navigation and robot-assisted techniques have made percutaneous fixation possible and are gradually being used in the upper cervical spine. Five consecutive patients with C1 LMF who underwent percutaneous lag screw osteosynthesis under the guidance of a new robotic system were reviewed retrospectively. Preoperative and postoperative computed tomography scans were used to specify the fracture types and to assess the efficacy of fracture reduction. The medical records were reviewed. Among the 5 patients, 4 underwent percutaneous lag screw reduction and fixation with the assistance of the robotic system through a posterior approach and 1 patient underwent a transoral approach. No intraoperative complications, such as screw malposition, neurologic deficit, and vertebral artery injury, occurred. Satisfactory fracture reduction and bone healing were achieved at postoperative follow-up. Robot-assisted percutaneous lag screw osteosynthesis is a viable option for C1 LMF. Different approaches can be selected according to the distribution of the fracture lines. With the posterior approach, the guidewire tends to deviate from the entry point because of skiving, and the technical problems need to be further solved. Screw implant by a transoral approach is comparatively easy to achieve, but the possibly of infection exists and should be monitored.

662 Navigation in Cervical Spine Surgery: A Review of Past and Current Uses

INTRODUCTION: The last two decades in spine surgery have resulted in an expansion of innovation and new enabling technologies. Within those new developments, spinal navigation has been adopted widely. Nonetheless, the use in the cervical spine remains a less explored METHODS: A scoping review of the literature was performed via PubMed. Limited to English and no date limit. Different search queries with MesH terms such as “Surgical Navigation Systems" "Spatial Navigation”, "Surgery, Computer-Assisted”, "Cervical Vertebrae", “cervical spine” with combination of OR and AND. Inclusion criteria: articles discussing the use of any navigation platform in the cervical spine. RESULTS: A total of 365 articles were found. After title and abstract selection, a total of 87 articles were reviewed. All the articles were retrospective. A total of 2101 patients underwent cervical procedures with spinal navigation, 54% were male. Average age of the cohort was 53.6 years. The Stealth navigation system (Medtronic) was the most commonly used followed by BrainLab and the large majority used CT based navigation. Degenerative conditions were the most common followed by trauma. There were 1872 total screws placed under navigation. Most common use for navigation was placement of cervical pedicle screws with a range of pedicle screw accuracy from 76.5-97.1%. The most common level for misplacement was C4. Additional uses include occipital and C1-2 fusion, corpectomies, transoral, transnasal approaches, and tumor localization. Direct complications from screw placement: C5 palsy, vertebral artery injury and dural tears. Mean follow up was 22.6 months. CONCLUSIONS: Spinal navigation in the cervical spine remains an understudied field. The current reports show good accuracy for placement of cervical pedicle screws, with minimal complications but other uses within the cervical spine remain somewhat limited. Given our evolving understanding of cervical pathology

Craniovertebral junction aneurysms

ObjectiveThe course of the vertebral artery and its relationship to the C0–1–2 structures render it particularly vulnerable to mechanical trauma. In the present study, we investigated the course of vertebral arteries along the craniovertebral junction (CJ) to cast light on the biomechanical aspects of aneurysm formation, focusing mainly on the relation of the vertebral artery injuries to the CJ bony landmarks. Herein, we report our experience with fourteen cases of craniovertebral junction vertebral artery (CJVA) aneurysms and their presentations, management, and outcomes. Materials and methodsWe extracted from 83 vertebral artery aneurysms only those 14 cases whose aneurysms were located at the C0–1–2. We reviewed all medical records, including operative reports and radiologic images. We divided the CJVA into 5 segments and then carefully reviewed the cases, largely focusing on the CJVA segments involved in the aneurysm. Angiographic outcomes were determined by angiography, which was scheduled at 3–6 months, 1, 2.5, and 5 years postoperatively. ResultsA total of 14 patients with CJVA aneurysms were included in the present study. 35.7 % had cerebrovascular risk factors, while 23.5 % had other predisposing factors such as an AVM, an AVF, or a foramen magnum tumor. Predisposing factors in the form of neck trauma, both direct and indirect, were identified in 50 % of cases. The segmental distribution of aneurysms was as follows: three (21.4 %) at CJV 1, one (7.1 %) at CJV 2, four (28.6 %) at CJV 3, two (14.3 %) at CJV 4, and four (28.6 %) isolated to the CJV 5 segment. Of the 6 indirect traumatic aneurysms, 1 (16.7 %) was located at CJV 1, 4 (66.7 %) were located at CJV 3 and 1 (16.7 %) was located at CJV 5. The 1/1 direct traumatic aneurysm (100 %) from the penetrating injury was located at CJV 1. 100 % of cases with cerebrovascular risk factors, the affected vessels were on the dominant side. 42.9 % of cases presented symptoms of a vertebrobasilar stroke. All 14 aneurysms were managed only endovascularly. 85.8 % of patients we implemented flow diverters only. 57.1 % of follow-up cases were completely occluded angiographically, and 42.9 % of cases were near-completely or incompletely occluded at 1, 2.5, and 5-year follow-ups. ConclusionsThe current article is the first report of a series of vertebral artery aneurysms located in CJ. Herein, the association of vertebral artery aneurysm, hemodynamics, and trauma is well established. We clarified all segments of the CJVA and showed that the segmental distribution of CJVA aneurysms significantly differs between traumatic and spontaneous cases. We showed that treatment with flow diverters should be the mainstay of CJVA aneurysm treatment.

Morphology analysis of the C2 pediculoisthmic component and feasibility of safe C2 pedicle screw placement: comparison of multiplanar reconstruction versus traditional radiographic methods

BackgroundPreoperatively evaluating the feasibility of safe C2 pedicle screw placement is the key to avoiding iatrogenic vertebral artery injury. However, it has not been verified whether the conventional CT measurements of C2 pediculoisthmic component (PIC) are reliable and accurate, and the results may lack validity. The purpose of this study is to analyze the evaluative performance of conventional CT measurements and to create an accurate predictor of morphometrics of C2 PIC.MethodsA total of 304 C2 PICs were measured in 152 consecutive patients who underwent CT examination of the cervical spine between April 2020 and December 2020. We obtained the morphometric parameters of C2 PIC by measuring minimum PIC diameter (MPD) in CT multiplanar reconstruction versus conventional measurements of transverse PIC width (TPW), oblique PIC width (OPW) and definition of high-riding vertebral artery (HRVA). The outer diameter measured less than 4 mm in MPD was regarded as the standard of precluding safe C2 pedicle screw insertion. The evaluative performance of the conventional CT measurements was assessed, and the correlation between conventional CT measurements and measurements in CT multiplanar reconstruction was calculated.ResultsThe parameters in OPW and MPD were measured significantly larger than those in TPW, and the preclusion of C2 pedicle screw placement evaluated from TPW and HRVA was significantly higher than that evaluated from OPW and MPD. The sensitivity of TPW was 93.09%, and the specificity was 79.31%. The sensitivity and specificity of OPW were 97.82% and 82.76%. The sensitivity of HRVA was 88.36%, and the specificity was 96.55%. Strong agreement with the highest correlation coefficient (0.879) and determination coefficient (0.7720) suggested that the outer diameter of OPW could be useful for the precise prediction of MPD.ConclusionsCT MPR allows accurate measurement of the narrowest section of the C2 PIC. The outer diameter of OPW could be simply measured and be useful for precise prediction of MPD, which makes C2 pedicle screw placement more safely than the conventional measurement of TPW and HRVA.

Treatment of intraspinal benign tumors in upper cervical vertebrae by modified recapping laminoplasty

To evaluate the effectiveness of modified recapping laminoplasty preserving the continuity of supraspinous ligament in the treatment of intraspinal benign tumors in upper cervical vertebrae and its influence on the stability of the cervical vertebrae. The clinical data of 13 patients with intraspinal benign tumors in upper cervical vertebrae treated between January 2012 and January 2021 were retrospectively analyzed. There were 5 males and 8 females, the age ranged from 21 to 78 years, with an average of 47.3 years. The disease duration ranged from 6 to 53 months, with an average of 32.5 months. The tumors located between C 1 and C 2. Postoperative pathology showed 6 cases of schwannoma, 3 cases of meningioma, 1 case of gangliocytoma, 2 cases of neurofibroma, and 1 case of hemangioblastoma. During operation the continuity of the supraspinal ligament were retained, the lamina ligament complex was lifted to expose the spinal canal via the approach of the outer edge of the bilateral lamina, and the lamina was fixed after the resection of the intraspinal tumors. Before and after operation, the atlantodental interval (ADI) was measured on three-dimensional CT; the effectiveness was evaluated by Japanese Orthopaedic Association (JOA) score, the neck dysfunction index (NDI) was used to evaluate the cervical function, and the total rotation of the cervical spine was recorded. The operation time was 117-226 minutes (mean, 127.3 minutes); the intraoperative blood loss was 190-890 mL (mean, 227.8 mL). The tumors were completely removed in all patients. There was no vertebral artery injury, aggravation of neurological dysfunction, epidural hematoma, infection, or other related complications. Two patients occurred cerebrospinal fluid leakage after operation, which were healed through electrolyte supplement and local pressure treatment of incision. All the patients were followed up 14-37 months, with an average of 16.9 months. Imaging examination showed no recurrence of tumor, displacement of vertebral lamina, loosening and displacement of internal fixator, and secondary reduction of vertebral canal volume. At last follow-up, JOA score significantly improved when compared with preoperative scores ( P<0.05). Among them, 8 cases were excellent, 3 cases were good, and 2 cases were medium, with an excellent and good rate was 84.6%. There was no significant difference in ADI, total rotation of the cervical spine, and NDI between pre- and post-operation ( P>0.05). The treatment of intraspinal benign tumors in upper cervical vertebrae with modified recapping laminoplasty preserving the continuity of the supraspinous ligament can restore the normal anatomical structure of the spinal canal and maintain the stability of the cervical spine.

Surgical Anatomy of Vertebral Artery in Relation to Atlantoaxial Instrumentation: A Cadaveric Study.

With the advent of pedicle screws and advanced instrumentation techniques, internal fixation and stabilization of upper cervical vertebrae are possible in fractures of an axis. However, the proximity of vertebral arteries (VAs) poses a unique challenge to surgeons during these procedures and can result in profound physical impairment to patients. Cadaveric studies contributing to fine anatomical details necessitate conducting such studies. After receiving due ethical permission, this descriptive cross-sectional study was carried out on 10 cadavers in the department of Anatomy, All India Institute of Medical Science (AIIMS) Rishikesh. Twenty VAs were dissected along their course, and measurements of parameters related to the axis and atlas vertebra were noted. The length of the pre-osseous segment related to the axis (VAX-1) on the right and left sides were from 3.8 to 14.5 mm (7.48±3.88 mm)and 4.46 to 10.5mm (6.94±2.01mm) respectively. The length of the osseous segment related to the axis (VAX-2) on the right side and left sides were from 6.82 to 31 mm (17.9±7.84mm) and 7.35 to 20 mm (15.6±4.53). The osseous segment of the VA related to the axis (VAX-2) shows genu (bend), which extends to a variable distance towards the midline. The mean distance of VA genu from the midline of the axis vertebral body on the right and left sides was 15.6mm and 17.5 mm, respectively. The percentage of superior articular facet (SAF) surface area of the axis occupied by the VA was 25-50% in nine and 50-75% in 11 cadavers, reflecting incomplete occupancy. The study suggests that for instrumentation of the axis vertebra in the midline, the minimum distance between the genu of both sides of VA segments, related to an osseous segment of the axis (VAX-2) and medial extent of the VA groove of the atlas, should be considered as a safe zone to minimize inadvertent VA injury. During atlantoaxial fixation through a posterior approach in interarticular, pars, and pedicle screws, the surgical anatomy of the VA in relation to the osseous segment of the VA within the transverse process of the axis should be kept in mind to avoid inadvertent VA injury.

Management of a penetrating vertebral artery injury in a peripheral hospital

Vertebral artery (VA) injuries in penetrating trauma are rare but can be life threatening. Management is often reliant on interventional radiology (IR), although such services may be lacking in peripheral centres. We report a case of a 22-year-old man who sustained a right VA injury from a stab wound to the posterolateral neck that was managed in a rural hospital. On presentation, the patient was initially haemodynamically stable but began exsanguinating heavily whilst undergoing imaging and was subsequently transferred to the operating theatre. Intraoperatively, bleeding was noted from the C5/C6 interforaminal space. Due to difficulty with exposure and lack of specialist surgical services, bimanual pressure was continuously applied to the wound whilst awaiting the arrival of a vascular surgeon and neuro-interventionalist who were transported by air from a tertiary hospital. At the time of angiography, bleeding had ceased and no further intervention was required. This case highlights the importance for surgeons in peripheral centres to be aware of some of the operative manouvres used in managing VA injuries including the utility of continued direct pressure. Moreover, it serves as a reminder that there remains a role for operative intervention in the unstable patient despite increasing reliance on radiological techniques to treat such injuries.

Posterior osteosynthesis with a new self-designed lateral mass screw-plate system for unstable atlas burst fractures

BackgroundIn the treatment of unstable atlas fractures using the combined anterior–posterior approach or the posterior monoaxial screw-rod system, factors such as severe trauma or complex surgical procedures still need to be improved despite the favourable reduction effect. This research described and evaluated a new technique for the treatment of unstable atlas fracture using a self-designed lateral mass screw-plate system.MethodsA total of 10 patients with unstable atlas fractures using this new screw-plate system from January 2019 to December 2021 were retrospectively reviewed. All patients underwent posterior open reduction and internal fixation (ORIF) with a self-designed screw-plate system. The medical records and radiographs before and after surgery were noted. Preoperative and postoperative CT scans were used to determine the type of fracture and evaluate the reduction of fracture.ResultsAll 10 patients were successfully operated with this new system, with an average follow-up of 16.7 ± 9.6 months. A total of 10 plates were placed, and all 20 screws were inserted into the atlas lateral masses. The mean operating time was 108.7 ± 20.1 min and the average estimated blood loss was 98.0 ± 41.3 ml. The lateral mass displacement (LMD) averaged 7.1 ± 1.9 mm before surgery and almost achieved satisfactory reduction after surgery. All the fractures achieved bony healing without reduction loss or implant failure. No complications (vertebral artery injury, neurologic deficit, or wound infection) occurred in these 10 patients. At the final follow-up, the anterior atlantodens interval (AADI) was 2.3 ± 0.8 mm and the visual analog scale (VAS) was 0.6 ± 0.7 on average. All patients preserved almost full range of motion of the upper cervical spine and achieved a good clinical outcome at the last follow-up.ConclusionsPosterior osteosynthesis with this new screw-plate system can provide a new therapeutic strategy for unstable atlas fractures with simple and almost satisfactory reduction.

Accuracy of atlantoaxial screw placement using computed tomography-based navigation system-assisted surgery: The single-level vertebral registration

ObjectivePosterior screw fixation via a C1 lateral mass screw combined with a C2 pedicle screw is a well-known technique for atlantoaxial instability. However, screw malposition can occur because of the complex anatomical structure of this region. This study aimed to evaluate the accuracy and risk factors of cortical breach following the C1 lateral mass and/or C2 pedicle screw insertion using a preoperative computed tomography (CT)-based navigation system with a single-level vertebral registration method. MethodsThis retrospective cohort study included patients who had undergone a C1 lateral mass and/or a C2 pedicle screw placement using a preoperative CT-based navigation system from January 2013 to March 2020 from the university hospital. The extent of screw deviation was classified as: within the pedicle (grade 0), out of pedicle < 2 mm (grade I), from 2 to 4 mm (grade II), and > 4 mm (grade III). The risk of cortical breach was evaluated using multivariate analysis. ResultsSeventy-eight C1 lateral masses and 71 C2 pedicle screws were inserted into 42 patients. The accuracy of screw placement was as follows: 133 grade 0 (89.3 %), 14 grade I (9.4 %), and two grade II (1.3 %). No screws required repositioning, and no vertebral artery injury or neurological deficit was associated with this technique. Additionally, a diameter of < 5 mm was associated with the cortical breach in the multivariate analysis. ConclusionsC1 lateral mass and C2 pedicle screw placement could be safely and effectively performed by using a preoperative CT-based navigation system with a single-level registration technique. The risk factors for cortical breach are the C1 lateral mass and C2 pedicle diameters.

Bone wax causing a middle trunk plexopathy following vertebral artery injury: a neuroradiological pitfall

BackgroundBone wax is a hemostatic agent widely used in surgery. Since it is neither absorbed nor metabolized, its use remains risky and a potential cause of complications. Even though its MRI radiological characteristics are distinguishable, it is generally misinterpreted as postoperative hematoma or trapped air. We report the first case in literature of brachial plexopathy due to the compressive mass effect of bone wax and the main clues that led us to establish this diagnosis prior to its surgical resection.Case presentationA 20-year-old male, victim of stabbing presented with an open wound of the right latero-cervical region with a vascular injury of the V2 segment of the right vertebral artery on CT angiography. He was first admitted for bleeding from the neck uncontrollable with external pressure. The patient underwent an emergency surgical vertebral artery ligation. Forty-eight hours later, he reported a feeling of paresthesia of right arm with right-sided weakness. Neurologic examination revealed a motor deficit of the right triceps and wrist extensor muscles and absence of the triceps reflex. A postoperative compression of the C7 cervical root or the middle trunk of brachial plexus was initially suspected. A cervical MRI demonstrated a T1- and T2-weighted images well-defined right mass located laterally to the spinal cord in the epidural space at the level of C6–C7 vertebrae with a signal-intensity void on both sequences. T2*-weighted images showed no signal attenuation. It did not enhance after contrast administration. An epidural hematoma was less probable since acute hematoma is typically hypointense on T2*-weighted images. Computed tomography helped rule out residual postoperative air trapped in the epidural space based on the density study of the mass compared to air. Finally, a residual surgical foreign material used for packing during the procedure was suspected. The massive use of bone wax was ultimately confirmed by the surgeon and surgically removed with complete immediate postoperative recovery.ConclusionsThis case highlights the importance of a nuanced critical approach of neurosurgeons and neuroradiologists when interpreting postoperative neuroimaging scans of the spine. It is crucial to always consider foreign body-related complications and to review the per-operative procedure in details.

The value of performing cerebrovascular CT angiography in major trauma patients: a 5-year retrospective review

To assess whether routine cerebrovascular imaging is required in all major trauma (MT) patients. All MT patients with cerebrovascular imaging between January 2015 and December 2020 were included in the study. Data were collated regarding the type of indication for computed tomography (CT) angiography imaging, time interval from the initial trauma, relevant trauma diagnoses on initial trauma imaging, and CT angiography. Findings, such as aneurysms, vascular malformations, luminal thrombus, venous sinus thrombosis, or vascular injury, were collated. Subsequent treatment with anti-coagulants/anti-platelets or surgical/radiological intervention was noted. Follow-up imaging was assessed for residual injury or complications. Two hundred and fifty of the 6,251 MT patients underwent dedicated cerebrovascular imaging and were included in the study. Of these 41 (16.4%) had cervical artery or venous sinus injury. Further positive vascular findings were identified in 25/250 patients who presented with an incidental stroke or a vascular abnormality and were mislabelled as MT patients at presentation. One patient with a carotid injury subsequently died following a large infarction. Another patient with vertebral artery injury suffered a non-lethal stroke. No patients underwent surgery or intervention. The present study showed that the overall incidence of detected blunt cerebrovascular injuries was very low (0.6%) and even lower for symptomatic vascular injury (0.03%). Routine cerebrovascular imaging is not recommended in all MT trauma patients, but instead, a continued case-by-case basis should be considered.

Erratum: Vertebral Artery Injury in the Cervical Spine.

Erratum: Vertebral Artery Injury in the Cervical Spine.

Surgical management of spinal schwannomas arising from the first and second cervical roots: Results of a cumulative case series.

Schwannomas of the first and second nerve roots are rare neurosurgical entities, harboring specific surgical features that make surgical resection particularly challenging and deserve specifics dissertations. This study is a retrospectively analysis of 14 patients operated in two different neurosurgical centers: the San Filippo Neri Hospital of Rome and the Federal Centre of Neurosurgery of Tjumen. In the last 6 years, 14 patients underwent neurosurgical resection of high cervical (C1-C2) schwannomas, in two different neurosurgical centers. Patients data regarding clinical presentation, radiological findings, and surgical results were retrospectively analyzed. The mean age was 50 years (range 13-74), the follow-up mean duration was 30 ± 8.5 (range 24-72 months), and there was no significant differences among different tumor locations (intradural, extradural, and dumbbell). Surgical results were excellent: gross total resection was achieved in all cases and there were no intraoperative complications or postoperative mortality. All patients presented postoperative clinical improvement except one who remained stable. Karnofsky performance status, at the last follow-up, confirmed a global clinical improvement. No vertebral artery (VA) injury neither spinal instability occurred; nerve root sacrifice was reported in one case. Neurosurgical treatment of C1-C2 schwannomas is associated with good outcomes in terms of extent of resection and neurological function. In particular, dumbbell shape and VA involvement do not represent limitations to achieve complete tumor resection and good clinical outcome. In conclusion, microsurgery represents the treatment of choice for C1-C2 schwannomas.

Posterior Exposure of the Vertebral Artery in the Subaxial Cervical Spine: A Cadaveric Study

Vertebral artery anomalies and anatomic variations noted from cadaveric dissections and imaging studies are well documented within the literature at the craniovertebral junction as well as subaxial cervical spine. Such abnormalities can lead to Vertebral artery injuries causing a myriad of comorbidities for patients. In such situations, Vertebral artery may need to be repaired especially if the dominant artery was injured. In this study, we describe a safe surgical approach to expose the Vertebral artery in the subaxial cervical spine using 6 formalin fixed cadavers to assess the feasibility of our approach. Neural foraminal decompression was performed to identify the nerve roots followed by complete resection of the inferior and superior articular processes at the intended levels. The pedicle was skeletonized, and the posterior wall of the transverse foramen was removed. The Vertebral artery could then be exposed between the two nerve roots. Multiple measurements were reported to guide the approach, including the Vertebral artery diameter between the nerve roots on the left and right side from C3-C7, the distance from midline to the medial edge of the Vertebral artery, and the distance from midline to the lateral edge of the Vertebral artery. To our knowledge, this is the first study describing a safe approach to expose the subaxial Vertebral artery.

Posterior circulation infarct without apparent vertebral artery injury following realignment of atlantoaxial dislocation

Abstract Risk of injury to normal vertebral artery (VA) unlike that associated with an anomalous VA is infrequent during posterior C1–C2 reduction for congenital atlantoaxial dislocation (AAD). An ischemic event resulting from such indirect injury is a rare occurrence. A 14-year-old boy with severe AAD/basilar invagination underwent C1–C2 joint manipulation and fixation with an uneventful intraoperative course. Although his immediate postsurgical period was unremarkable, he sustained sudden and rapid neurological worsening on day 3. He developed multiple posterior fossa infarcts and finally succumbed. VA can be indirectly injured possibly due to excessive distraction/manipulation of C1–C2 joints. The lesson learnt is that anticipation of such injuries along with proactive anticoagulation treatment can potentially alter patient outcome.

Management of the Vertebral Artery in Craniovertebral Junction Stabilization Surgery.

The vertebral artery (VA) has an intimate relationship with the bones of the craniovertebral junction. An exact understanding of the VA anatomy in general and in the specific surgical case in particular is absolutely necessary in order to avoid intraoperative vascular injury. The course of the VA on the inferior aspect of the superior facet of the C2 vertebra makes it susceptible to damage during transarticular and interarticular fixation with the screw insertion in the adjacent lateral mass. The consequences of the intraoperative VA injury will depend on the patency of other arteries supplying the brain. In case of this complication, quick decision-making is essential to avoid excessive blood loss and to preserve adequate cerebral blood flow.

Canadian Spine Society

# Abstract 57. Radiographic reporting in adolescent idiopathic scoliosis: Is there a discrepancy comparing radiologists’ reports and surgeons’ assessments? {#article-title-2} Cobb angle measurement is the standard method for quantification of scoliosis in adolescent idiopathic scoliosis (AIS),