Delayed subarachnoid hemorrhage following failed odontoid screw fixation

Iatrogenic vascular injury is a rare but potentially devastating complication of cervical spine instrumentation. The authors report on a patient who developed an anterior spinal artery pseudoaneurysm associated with delayed subarachnoid hemorrhage after undergoing odontoid screw placement 14 months earlier. This 86-year-old man presented with spontaneous subarachnoid hemorrhage (Fisher Grade 4) and full motor strength on neurological examination. Imaging demonstrated pseudarthrosis of the odontoid process, extension of the odontoid screw beyond the posterior cortex of the dens, and a pseudoaneurysm arising from an adjacent branch of the anterior spinal artery. Due to the aneurysm's location and lack of active extravasation, endovascular treatment was not attempted. Posterior C1-2 fusion was performed to treat radiographic and clinical instability of the C1-2 joint. Postoperatively, the patient's motor function remained intact. Almost all cases of vascular injury related to cervical spine instrumentation are recognized at surgery. To the authors' knowledge, this is the first report of delayed vascular injury following an uncomplicated cervical fixation. This case further suggests that the risk of this phenomenon may be elevated in cases of failed fusion.     

Vertebral artery injury in cervical spine surgery: anatomical considerations,management, and preventive measures

Background contextVertebral artery (VA) injury can be a catastrophic iatrogenic complication of cervical spine surgery. Although the incidence is rare, it has serious consequences including fistulas, pseudoaneurysm, cerebral ischemia, and death. It is therefore imperative to be familiar with the anatomy and the instrumentation techniques when performing anterior or posterior cervical spine surgeries.PurposeTo provide a review of VA injury during common anterior and posterior cervical spine procedures with an evaluation of the surgical anatomy, management, and prevention of this injury.Study designComprehensive literature review.MethodsA systematic review of Medline for articles related to VA injury in cervical spine surgery was conducted up to and including journal articles published in 2007. The literature was then reviewed and summarized.ResultsOverall, the risk of VA injury during cervical spine surgery is low. In anterior cervical procedures, lateral dissection puts the VA at the most risk, so sound anatomical knowledge and constant reference to the midline are mandatory during dissection. With the development and rise in popularity of posterior cervical stabilization and instrumentation, recognition of the dangers of posterior drilling and insertion of transarticular screws and pedicle screws is important. Anomalous vertebral anatomy increases the risk of injury and preoperative magnetic resonance imaging and/or computed tomography (CT) scans should be carefully reviewed. When the VA is injured, steps should be taken to control local bleeding. Permanent occlusion or ligation should only be attempted if it is known that the contralateral VA is capable of providing adequate collateral circulation. With the advent of endovascular repair, this treatment option can be considered when a VA injury is encountered.ConclusionsVA injury during cervical spine surgery is a rare but serious complication. It can be prevented by careful review of preoperative imaging studies, having a sound anatomical knowledge and paying attention to surgical landmarks intraoperatively. When a VA injury occurs, prompt recognition and management are important.     

Vertebral artery (V2) pseudo-aneurysm after surgery for cervical schwannoma. How to prevent it and a review of the literature

Study designCase report and review of the literature.ObjectiveTo prevent and manage a suspected iatrogenic vertebral artery injury during a cervical spine anterior approach.Summary of background dataThe anterior spine approach is a common surgery with few complications. One of the rare but significant risks is vertebral artery injury. Consequences of vertebral artery injuries are often delayed. Therefore, it is essential to prevent this complication and to know how when exploring after a suspected vertebral artery injury.MethodsReport of a case and review of the literature. A 61-year-old woman presented with a cervical schwannoma involving the C5–C6 foramen. She had undergone surgery 22 years before by the posterior approach. We performed an anterior cervical approach. After 12 days, a vertebral artery pseudo-aneurysm occurred. Our review of the literature is focalized on vertebral artery injuries during cervical surgery by the anterior approach.ResultsThe patient was treated by coil embolization with a good outcome. To our knowledge, only 6 cases of vertebral artery pseudo-aneurysm after surgery have been reported in the literature.ConclusionAccording to the literature, vertebral artery pseudo-aneurysms resulting in anterior cervical approach are rare but their consequences could be severe. Prevention begins by detailed surgical planning. Peroperative imaging is helpful. Any suspected vertebral artery injury should postpone a contralateral approach before angiographic imaging.     

颈椎手术中并发椎动脉损伤的诊断与治疗

 目的 探讨颈椎手术中并发椎动脉损伤的发生原因、治疗及预防。方法 回顾性分析2002年10月至2012年4月颈椎手术中并发椎动脉损伤的7例患者资料,男6例,女1例;年龄23～65岁,平均48.9岁;脊髓型颈椎病5例,颈椎外伤合并C^4,5半脱位1例,氟骨症致颈椎管狭窄1例。椎动脉损伤均为单侧,左侧4例,右侧3例。分析颈椎手术中并发椎动脉损伤的原因、处理过程及预后。结果颈椎前路手术4例,其中2例用环钻减压时偏离中线损伤椎动脉,1例切除椎间盘时刮匙过于偏外损伤椎动脉,1例颈椎外伤患者由于Ｃ^4,5半脱位造成椎动脉迂曲,减压时冲击式咬骨钳损伤椎动脉。颈椎后路手术3例,其中2例为行C4侧块螺钉固定时钻头偏外损伤椎动脉;1例氟骨症致颈椎管狭窄者在切除寰椎后弓时咬骨钳损伤椎动脉,术中出现椎动脉损伤后,迅速填塞压迫止血并关闭伤口,但术后4周发生迟发性出血,采用椎动脉栓塞止血及颈后路血肿清除术治疗。7例患者均未发生脑梗塞,其中2例患者术后出现一过性头晕。结论 椎动脉损伤是颈椎手术的严重并发症,其损伤原因与手术失误、解剖变异等有关;采用直接压迫及椎动脉栓塞治疗效果确切。     

Forty-three cases of vertebral artery trauma

Forty-three cases of injury to the vertebral artery are reviewed. Trauma to these cervical vessels requires deep tissue penetration, most often as a result of gunshot or stabwounds. The majority of patients are hemodynamically stable, although serious hemorrhage and death may result from injury to this artery alone. Injury to the vertebral artery was frequently associated with cervical spine fracture and local neural damage. However, no patient presented with or developed neurologic sequelae attributable to vertebral-basilar ischemia. Arteriography accurately identified the site of injury, but the specific arteriographic diagnosis can be unreliable. Two of 13 patients (15%) treated by proximal vascular control alone had postoperative vascular complications. While direct surgical intervention with proximal and distal arterial ligation is the appropriate treatment of acute injuries, in some cases there may be a role for conservative treatment of minimal injuries. In this series, mortality related to a vertebral artery injury was low (4.7%), likely as a result of accurate diagnosis and prompt operative intervention.     

椎动脉扭曲与颈椎前路减压的危险性分析

目的：探讨椎动脉扭曲与颈椎前路减压椎动脉损伤的危险性。方法：32例拟诊为颈椎病、颈椎间盘突出症的患者,同时接受颈椎平片、MRI和椎动脉磁共振血管成像（MRA）检查。结果：23例椎动脉直行无扭曲,5例椎动脉有轻度扭曲,4例椎动脉明显扭曲突入钩椎关节内侧。椎动脉扭曲与颈椎退行性变有关。结论：颈椎严重退行性变可导致椎动脉扭曲突入钩椎关节内,从而增加颈椎前路减压损伤椎动脉的危险。     

Tortuous course of the vertebral artery and anterior cervical decompression: a cadaveric and clinical case study

STUDY DESIGN: Both the cadaveric and clinical examples of anomalous vertebral artery courses are described. The incidence of this anomaly in the general population and recognition, complications, and treatment options for these patients when undergoing anterior cervical decompression are discussed. OBJECTIVES: Cadaveric study: In this study vertebral artery's course through the cervical spine in the adult population was analyzed. The relation between an abnormal vertebral artery course and surgical landmarks are described. Clinical study: Complications and alternative treatment methods for decompression in patients with the anomaly are described. SUMMARY OF BACKGROUND DATA: The incidence of anomalous vertebral artery course is low, but failure to recognize a medially located vertebral artery may result in a life-threatening iatrogenic injury during decompression. Neither the relation between the vertebral arteries and the surgical landmarks nor the guidelines for decompression in the face of a tortuous vertebral artery have been well described. METHODS: Transverse foramens of the cervical spine were measured in 222 cadaveric spines. The measurements were taken describing the relation between transverse foramens and other surgical landmarks. Three patients with anomalies were identified in clinical practice. The complications and treatment options are identified in these patients. RESULTS: In the cadaveric specimens, a 2.7% incidence of tortuous vertebral artery course was identified. In these abnormal specimens, the transverse foramen was located an average of 0.14 mm medial to the joint of Luschka. In one patient, the abnormal course of the vertebral artery was recognized after laceration of the artery during a routine corpectomy. Anomalies in the other two patients were recognized before surgery, and the patients underwent modified anterior decompression by combining a discectomy at the anomalous level with a corpectomy at other levels. Vertebral artery ectasia is identifiable on axial magnetic resonance or computed tomographic images. CONCLUSIONS: Aberrant vertebral artery is rare. Preoperative recognition and appropriate modification of anterior decompression can yield excellent clinical results without risking significant complications.     

Vertebral artery pseudoaneurysm complicating posterior C1-2 transarticular screw fixation: case report

BACKGROUND: Vertebral artery injury during posterior C1-2 transarticular screw fixation occurs in approximately 3% of patients and may remain asymptomatic or result in arteriovenous fistulae, occlusion, narrowing, or dissection of the vertebral artery, and lead to transient ischemic attacks, stroke, or death. CASE DESCRIPTION: This is the first report of a pseudoaneurysm resulting from damage to the vertebral artery during the procedure. This 31-year-old male underwent posterior C1-2 transarticular screw fixation for unstable os odontoideum. Injury to the left vertebral artery occurred while the hole for the left screw was being drilled. Temporary control of bleeding with local pressure was followed by immediate postoperative angiography that revealed a left vertebral artery pseudoaneurysm. Although the patient remained asymptomatic, therapeutic anticoagulation was instituted 6 hours postoperatively. Increasing size of the pseudoaneurysm was noted on routine follow-up angiography 4 weeks later. Endovascular occlusion of the pseudoaneurysm and left vertebral artery, with preservation of vertebrobasilar flow through the right vertebral artery, was accomplished without neurological consequence. CONCLUSIONS: Vertebral artery pseudoaneurysm complicating posterior C1-2 transarticular screw fixation may be effectively treated with endovascular approaches.     

Operative treatment for cervical fracture and dislocation with blunt unilateral vertebral artery injury

Objective： To investigate risks and clinical effects of operative treatment for cervical vertebral fracture and dislocation associated with unilateral vertebral artery injury. Methods： This group consisted of 76 cases of closed cervical spine trauma combined with unilateral vertebral artery injury （23 cases of bilateral facet dislocation, 28 unilateral facet dislocation and 25 fracture）. All patients underwent prospective examination of cervical spine MRI and vertebral artery two-dimensional time-of-flight （2D TOF） magnetic resonance angiography （MRA）, and anterior cervical decompression. The healthy vertebral artery paths were evaluated before the surgery, and were protected during the surgery according to the anatomical signs. Results： There were no acute or chronic clinical dam- age symptoms in 76 cases after surgery. No neural damage symptoms were observed in patients with normal neural functions. The neural functions of incomplete paralyzed patients were improved in different grades. Conclusions： Reliable anterior operation can produce good results for cervical fracture and dislocation with unilateral vertebral artery injury. Detecting the course of uninjured vertebral artery before operation and locating the anatomical site during operation are effective to avoid damaging vertebral artery of uninjured side.     

The efficacy of using an image-guided Kerrison punch in performing an anterior cervical foraminotomy. An anatomic analysis.

STUDY DESIGN: This study comprised two parts: first, a feasibility study to determine the efficacy of using an image-guided Kerrison punch while performing a foraminotomy during an anterior cervical decompression and, second, an anatomic analysis using vector measurement to determine the distance from the entrance of the neuroforamen to the medial margin of the vertebral artery in the subaxial cervical spine. OBJECTIVE: To assess the feasibility of using an image-guided Kerrison punch when performing an anterior foraminotomy and to obtain data regarding the distance from the vertebral artery to the entrance of the neuroforamen. SUMMARY OF BACKGROUND DATA: The documented incidence of catastrophic iatrogenic vertebral artery injury in anterior cervical decompression is low. The use of a real-time image-guidance surgical system should reduce the risk of this complication. METHODS: Twelve cadaveric cervical spines were harvested. Standard anterior cervical discectomies with bilateral foraminotomies were performed in the subaxial cervical spine using an image-guided Kerrison. Surgically significant morphometric data were measured using a computer-assisted image-guided surgical system. RESULTS: Successful navigation into all neuroforamina in the subaxial cervical spine was attained using the image-guided Kerrison punch. The vector measurement from the neuroforamen to the vertebral artery averaged 5.8 +/- 1.2 mm at C3-C4, 6.5 +/- 1.6 mm at C4-C5, 7.9 +/- 1.4 mm at C5-C6, and 9.1 +/- 1.8 mm at C6-C7. Statistically significant differences (P < 0.05) were found between all cervical levels except C3-C4 and C4-C5. CONCLUSION: An image-guided Kerrison punch may be used successfully when performing cervical foraminotomies during an anterior cervical discectomy, thus eliminating the risk of potential vertebral artery injury. These data confirm previous findings by other authors. Knowledge of these data may aid the spine surgeon in performing a foraminotomy during anterior cervical decompression.     

Vertebral artery occlusion after acute cervical spine trauma

STUDY DESIGN: A retrospective study of vertebral artery injury diagnosed during the last 6 years in our institution. OBJECTIVES: To determine the clinical and radiologic features of vertebral artery injury. SUMMARY OF BACKGROUND DATA: Extracranial occlusion of the vertebral artery associated with cervical spine fracture is uncommon and can cause serious and even fatal neurologic deficit due to back lifting and cerebellar infarction. Magnetic resonance imaging and magnetic resonance angiography are extremely helpful in the examination of acute injuries of the cervical spine. METHODS: Magnetic resonance imaging and magnetic resonance angiography were performed at the time of injury. RESULTS: The authors reviewed six patients with cervical spine fractures who were diagnosed with a unilateral occlusion of the vertebral artery by means of magnetic resonance imaging/magnetic resonance angiography. One patient had signs of vertebrobasilar insufficiency and another with complete cord lesion had cerebellar and back lifting infarctions. Surgical anterior spinal fusion was performed in five patients, and one was treated by traction and orthosis. At the time of discharge, five patients had no vertebrobasilar symptoms, and the patient who experienced vertebrobasilar territory infarctions showed no progression of the neurologic damage. CONCLUSIONS: Vertebral artery injury should be suspected in cervical trauma patients with facet joint dislocation or transverse foramen fracture. Magnetic resonance imaging/magnetic resonance angiography is a helpful test to rule out vascular injury. Vertebral artery injury affects the extracranial segment at the same level as the cervical fracture. This is a retrospective review that did not permit drawing conclusions about the effects of early surgical stabilization in the treatment of cervical spine injuries with associated vertebral artery injury; however, surgical stabilization may avoid propagation and embolization of the clot located at the site of the lesion.     

The vertebral artery: surgical anatomy

Anterior cervical decompressive surgery is widely performed for spondylosis, herniated intervertebral disk, tumor, infection, and trauma in the subaxial cervical spine region. Laceration of the vertebral artery is the most challenging of surgical dilemmas during anterior cervical spine surgery, as gaining control of the massive hemorrhage from a ruptured vertebral artery is difficult and could possibly result in an uncertain neurologic morbidity. As such, the understanding the surgical anatomy of the vertebral artery is essential to prevent iatrogenic injuries.     

Fatal basilar artery thrombosis after traumatic cervical facet dislocation. Case report

The authors detail a rare case of basilar artery thrombosis in a patient with traumatic cervical spine facet dislocation. Although the patient's deficits could initially be explained by the spinal injury, deterioration to a "locked-in-state" could not. In addition to vertebral artery injuries, the basilar artery can also be indirectly involved in cases of cervical spine trauma. In the rare viable patient, immediate reduction of cervical spine dislocation may allow endovascular thrombolysis, if not otherwise contraindicated.     

Fracture de l’odontoïde : hémorragie sous-arachnoïdienne à distance d’un vissage odontoïdien. À propos d’un cas et revue de la littérature

Odontoid fractures have been classified by Anderson and D’Alonzo into three main categories. The most unstable injuries, type II fractures involve the base of the odontoid peg at the junction with the C2 body. Due to the proximity of vital neural structures, fracture of the odontoid process may result in instability and fatal neurological damage. Treatment aims to re-establish stability of the atlanto-axial complex by restoring the odontoid process. This may be achieved by conservative or surgical treatment. Anterior screw fixation of the odontoid peg is an interresting alternative surgical option but this technique has a significant complication rate. However, vascular injury is very rare with three case reported in the literature: one case of an intracranial vertebral artery (VA) injury, one case of a cervical internal carotid artery (ICA) injury and one case of anterior pseudoaneurysm of the spinal artery branch. We report a new case of long term vascular injury after screw fixation revealed by a subarachnoid hemorrhage. We discuss the incidence, the mechanisms of injury and the conditions necessary for the occurrence of this complication.     

Occipital artery to extradural vertebral artery bypass procedure. Case report

A 17-year-old boy suffered blunt trauma to the posterior cervical spine and later developed vertebrobasilar transient ischemic attacks refractory to medical management. At angiography, a pseudoaneurysm of the distal left vertebral artery was found. By means of a posterior midline approach, an extradural occipital artery to vertebral artery anastomosis was performed and the affected vertebral artery was clipped distal to the pseudoaneurysm. The indications for this procedure, the operative approach, and the clinical outcome are described.     

Poor surgical technique in cervical plating leading to vertebral artery injury and brain stem infarction--case report

BACKGROUND: Lateral mass plating is a safe fixating system for lower cervical fractures. Brain stem infarction after cervical lateral mass screw plating has not been reported in previous literature. We report a case of poor surgical technique leading to vertebral artery injury and brain stem infarction after cervical lateral mass plating. CASE DESCRIPTION: A 41-year-old male patient was transferred to our hospital because of hemiparesis and dysarthria immediately after lateral mass plating for fracture and dislocation of the fifth and sixth cervical vertebrae. Brain magnetic resonance imaging showed infarction of the left posterior inferior cerebellar artery territory, and the vertebral artery angiography showed complete occlusion of the left vertebral artery. The cervical computed tomography revealed a left screw of the fifth and sixth cervical vertebrae penetrating the central portion of the transverse foramen. The patient was managed with anticoagulant and supportive therapy only, with subsequent improvement of hemiparesis and dysarthria. CONCLUSIONS: Poor surgical technique of lateral mass plating in the cervical spine could lead to vertebral artery injury and even brain stem infarction. Postoperative brain infarction in cervical fusion could be a complication of the usually safe lateral mass plating of the cervical spine.     

Lateral cervical spine dislocation and vertebral artery injury.

Although anterior and posterior traumatic displacement of cervical vertebrae are commonly noted, and the devastating neurological deficits associated with these injuries have been amply defined, lateral displacement with fractures has been rarely recognized, and the clinical significance of this injury has been overlooked. This report describes five cases of cervical spine fractures with lateral dislocation. All patients had lateral and anteroposterior cervical spine radiographs as well as cervical angiography or postmortem study demonstrating either complete occlusion or significant impairment of flow of the vertebral arteries. Two cases had traumatic vertebral artery occlusion with secondary medullary and cerebellar infarction resulting in the patient's death. Vertebral artery injury apparently is not uncommon in this particular type of fracture. The diagnosis of these vascular injuries may require angiography or magnetic resonance angiography. A vertebral occlusion or dissection is a problem of considerable complexity, requiring individualized management depending on the patient's symptomatology, location and nature of the injury, and time lapsed since the injury.     

Lateral and lateral anterior approaches in tumors of the cervical vertebrae

The limit of the standard anterior and posterior approaches on the cervical spine is a small area including the pedicle and transversary process. However, this area contains the vertebral artery and the merging cervical roots. The lateral-anterior route gives access to both structures while the lateral one leads mainly to the intervertebral foramen and nerve roots. Both techniques are described with stress on the great advantages of the lateral-anterior route: easy exposure, large operative field, possibility of complementary arthrodesis and venous graft by-pass on the vertebral artery. Experience on 14 cervical bony tumors resected through the lateral-anterior approach is reported. Complementary techniques were performed in 5 cases: carotid-vertebral artery by-pass in 1, laminectomy in 2 and bone grafting in 2. Therefore, the lateral anterior approach is considered a good way to deal with the intermediate part of the cervical spine.     

Masking of vertebral artery dissection by severe trauma to the cervical spine

STUDY DESIGN: A prospective case study was performed. OBJECTIVES: To illustrate the association of cervical trauma with vertebral artery dissection, and to propose a diagnostic and therapeutic algorithm for suspected traumatic vertebral artery dissection. SUMMARY OF BACKGROUND DATA: Vertebral artery dissection is a recognized but underdiagnosed complication of trauma to the cervical spine. Symptoms of spinal cord injury, however, may obscure those of vertebral artery dissection, presumably causing gross underdiagnosis of this complication. METHODS: All patients with vertebral artery dissection admitted to the authors' facility between 1992 and 1997 were screened for cervical trauma. RESULTS: This article presents four patients with severe trauma to the cervical spine, defined as luxation, subluxation, or fracture, in whom symptoms of vertebral artery dissection developed after a delay ranging from several hours to weeks. The traumatic vertebral artery dissection typically was located at the site of vertebral injury or cranial to it. One patient with fracture of the odontoid process survived symptom free without ischemic brain infarctions. Another patient survived with traumatic quadriplegia in addition to large cerebellar and posterior cerebral artery infarctions. Two patients died as a result of fulminant vertebrobasilar infarctions, both with only moderate impairment from the primary spinal cord injury. CONCLUSIONS: Early signs of vertebral artery dissection include head and neck pain, often localized to the site of intimal disruption, which may be disguised by the signs of the spinal injury. Early Doppler ultrasound and duplex sonography as a noninvasive screening method should be performed for patients with severe trauma to the cervical spine. In cases of vertebral artery dissection, immediate anticoagulation should be initiated. Traumatologists should be aware of this complication in evaluating patients with severe trauma of the cervical spine, and also for a variety of forensic reasons.