Traumatic vertebral arteriovenous fistula associated with cervical spine fracture

The subatlantic triangle: gateway to early localization of the atlantoaxial vertebral artery

OBJECTIVE Exposure of the vertebral artery (VA) between C-1 and C-2 vertebrae (atlantoaxial VA) may be necessary in a variety of pathologies of the craniovertebral junction. Current methods to expose this segment of the VA entail sharp dissection of muscles close to the internal jugular vein and the spinal accessory nerve. The present study assesses the technique of exposing the atlantoaxial VA through a newly defined muscular triangle at the craniovertebral junction. METHODS Five cadaveric heads were prepared for surgical simulation in prone position, turned 30°-45° toward the side of exposure. The atlantoaxial VA was exposed through the subatlantic triangle after reflecting the sternocleidomastoid and splenius capitis muscles inferiorly. The subatlantic triangle was formed by 3 groups of muscles: 1) the levator scapulae and splenius cervicis muscles inferiorly and laterally, 2) the longissimus capitis muscle inferiorly and medially, and 3) the inferior oblique capitis superiorly. The lengths of the VA exposed through the triangle before and after unroofing the C-2 transverse foramen were measured. RESULTS The subatlantic triangle consistently provided access to the whole length of atlantoaxial VA. The average length of the VA exposed via the subatlantic triangle was 19.5 mm. This average increased to 31.5 mm after the VA was released at the C-2 transverse foramen. CONCLUSIONS The subatlantic triangle provides a simple and straightforward pathway to expose the atlantoaxial VA. The proposed method may be useful during posterior approaches to the craniovertebral junction should early exposure and control of the atlantoaxial VA become necessary.

Bilateral cerebellar and brain stem infarction resulting from vertebral artery injury following cervical trauma without radiographic damage of the spinal column: a case report

Vertebral artery injury can be a complication of cervical spine injury. Although most cases are asymptomatic, the rare case progresses to severe neurological impairment and fatal outcomes. We experienced a case of bilateral cerebellar and brain stem infarction with fatal outcome resulting from vertebral artery injury associated with cervical spine trauma. A 69-year-old male was admitted to our hospital because of tetraplegia after falling down the stairs and hitting his head on the floor. Marked bony damage of the cervical spine was not apparent on radiographs and CT scans, so the injury was initially considered to be a cervical cord injury without bony damage. However, an intensity change in the intervertebral disc at C5/C6, and a ventral epidural hematoma were observed on MRI. A CT angiogram of the neck showed the right vertebral artery was completely occluded at the C4 level of the spine. Forty-eight hours after injury, the patient lapsed into drowsy consciousness. The cranial CT scan showed a massive low-density area in the bilateral cerebellar hemispheres and brain stem. Anticoagulation was initiated after a diagnosis of the right vertebral artery injury, but the patient developed bilateral cerebellar and brain stem infarction. The patient's brain herniation progressed and the patient died 52 h after injury. We considered that not only anticoagulation but also treatment for thrombosis would have been needed to prevent cranial embolism. We fully realize that early and appropriate treatment are essential to improve the treatment results, and constructing a medical system with a team of orthopedists, radiologists, and neurosurgeons is also very important.

Traumatic arteriovenous fistula of the posterior inferior cerebellar artery treated with endovascular coil embolization: case report

BACKGROUND

High-flow intracranial arteriovenous (AV) fistulas associated with giant varices are rare lesions. These varices can present with symptoms from mass effect, spontaneous hemorrhage, and seizures to cardiac failure. Direct AV fistulas of the posterior inferior cerebellar artery (PICA) are extremely rare lesions, with only two cases reported in the literature.

CASE DESCRIPTION

The authors present an unusual case of a 25-year-old male with a direct AV fistula of the PICA that resulted from a fracture of the occipital condyle. This high-flow AV fistula drained into a giant varix of the vein of the lateral recess that compressed the brainstem, resulting in a Wallenberg syndrome. The patient underwent embolization of the proximal PICA feeding the fistula with a Guglielmi detachable coil (GDC), which resulted in thrombosis of the varix. A postembolization angiogram showed occlusion of the PICA AV fistula and draining varix. A computed tomography (CT) scan performed at a 10-month follow-up visit showed dramatic decompression of the brainstem. Although the patient continued to have some sensory changes secondary to Wallenberg syndrome, he was otherwise doing well neurologically.

CONCLUSION

The treatment of this lesion is difficult because of its location near the brainstem. Postocclusion edema or hemorrhage can result in mass effect and life-threatening brainstem compression. Our patient, whose AV fistula was caused by trauma, was treated effectively with GDC embolization.

Tratamento endovascular de fístula arteriovenosa vertebral espontânea em criança: relato de caso

Fístulas espontâneas da artéria vertebral são raras malformações arteriovenosas entre a artéria vertebral e um vaso circunvizinho. Relatamos um caso de fístula arteriovenosa, não traumática, em uma criança de 9 anos de idade, submetida a tratamento por via endovascular. Sob anestesia geral e controle fluoroscópico, empregou-se a técnica endovascular para posicionar um balão destacável de látex, dessa forma ocluindo totalmente o trajeto fistuloso. Resolução clínica e angiográfica foi obtida, e não houve complicações relacionadas com o procedimento de embolização. O resultado observado comprova que a embolização especialmente oclusão com balões descartáveis, tornou-se o tratamento padrão para esta enfermidade.

Vertebral artery trauma

Vertebral artery trauma is not commonly seen by forensic pathologists. The experience of vertebral artery trauma at the Victorian Institute of Forensic Medicine (30 cases) is summarized and reviewed in the light of the literature. Causes of vertebral artery trauma are discussed. In case 1, the history and timing of the injury raise the question as to whether the vertebral artery dissection occurred before the episode of trauma, that is, was spontaneous or resulted from trauma. Moreover, underlying vertebral artery disease was present, raising the question as to how much trauma was needed to cause vertebral artery dissection. In case 2, despite the history of head/neck trauma, a neurosurgeon considered the subarachnoid hemorrhage was spontaneous, due most likely to ruptured saccular aneurysm or arteriovenous malformation. In case 3, the vertebral artery rupture was not diagnosed in the setting of multiple injuries. Case 4 is an example of prolonged survival with delayed onset of symptoms following vertebral artery trauma. Case 5 is an example of the not uncommon scenario of homicidal vertebral artery trauma accounting for basal subarachnoid hemorrhage, rapid collapse and death. Cases 1 and 4 indicate that relatively normal activity may be possible following vertebral artery trauma in some cases (at least for a time). Cases 1 and 4 are also examples of intracranial vertebral artery dissection.

Traumatic lesion of the extracranial vertebral artery--a note-worthy potentially lethal injury

The autopsy findings from routine neuropathological investigations of the cervical spine after any history of trauma emphasized the vulnerability of the extracranial vertebral arteries. In 21 cases with trauma to the head and neck, normal autopsy procedures did not succeed in revealing an obvious cause of death. Traumatic lesions of the spinal cord such as contusion or neurorrhexis were seen in 10 cases. In 15 cases we observed different degrees and stages of traumatic lesions of the extracranial vertebral arteries. Sudden death due to acute brain stem ischemia might be considered as an explanation in some of these cases. Six case reports with traumatic vertebral artery (VA) lesions after severe or minor extracranial trauma are presented. A review of the literature revealed that this vascular injury has only rarely been directly established by gross pathological examination. Possible consequences of blunt trauma to the head and neck include angiorrhexis, subintimal, intramural and perivascular hemorrhage leading to a partial narrowing of the injured vessel. These processes can be complicated by thrombosis. Unilateral VA obliteration may be an occult risk of acute brain stem ischemia when associated with contralateral reduction of the posterior circulation.

Vertebral arteriovenous fistulae. Report of two cases and review of the literature

Two patients with vertebral arteriovenous fistulae were treated at the Neurosurgical Clinic of the City Hospital of Hannover between 1981 and 1988. Both patients were males, 19 and 29 year old. The fistulae were secondary to cervical gunshot wounds. Both patients complained of a loud cephalic noise; 1 patient had a non pulsating neck mass. A systolic cervical bruit was heard in both cases. One patient had an incomplete mid-cervical Brown-Sequard syndrome. The fistulae involved the second portion of the vertebral artery: 1 fistula was fed, in addition to the vertebral artery, by the deep cervical artery. Venous drainage was through intraspinal plexus, vertebral vein, deep cervical veins and internal jugular vein. One patient was treated with a direct surgical trapping of the vertebral artery proximal and distal to the fistula: the other patient, in addition to direct surgical vertebral artery trapping, received an endovascular balloon occlusion of the deep cervical artery. After treatment the fistulae disappeared, both clinically and angiographically.

Blunt injuries to the carotid and vertebral arteries

A small series of patients with blunt injury to eigher a carotid or vertebral artery is presented. In three patients the injury was recognized relatively promptly. Two underwent surgery and one was observed with reasonably good results. In two patients the injury was unrecognized, resulting in death in one patient and in a severe, fixed, long-term neurologic deficit in the other. It appears likely that reconstruction may be the treatment of choice in any patient with angiographically proven injury unless coma or severe dense hemiplegia is present.

Surgical approach to the whole length of the vertebral artery with special reference to the third portion

A lateral route between the SCM and the lateral border of the internal jugular vein is defined from an anatomical study for exposure of the VA. It offers the simplest route for controlling any part or the whole length of the VA, including its intracranial portion. Surgical indications are discussed on the basis of our experience in eight cases with, in all cases, control of the VA in its third segment between C2 and the foramen magnum. Arteriovenous malformations are the most frequent indications; two cases were treated by direct approach and one by exclusion and anastomosis between the internal carotid artery and the vertebral artery at C1-C2. TUmours of the lateral cervical space (one haemangiopericytoma and one jugular glomus tumour) or of the posterior fossa extruding out of the foramen magnum or the jugular foramen (one meningioma) may require control of the VA. Traumatic lesions (one case) or compression by an osteophytic spur are also indications for this approach. Wall lesions of the VA (aneurysm or stenosis) are best treated by exclusion and anastomosis between either the carotid or the subclavian artery and the vertebral artery at C1-C2 level. One case of aneurysmal dysplasia was cured by anastomosis between the subclavian artery and the vertebral artery at C1-C2 with a saphenous vein graft and clipping of the VA proximal to the by-pass. Radiological examinations are fundamental for diagnosis, treatment when embolization is necessary, and choice of surgical treatment, according to the importance of the contralateral VA and the medullary branches.

Vertebral arteriovenous fistulas

Vertebral arteriovenous fistulas are rare. A report of two cases is presented with problems related to diagnosis and therapy. An alternative approach to surgical management is given.