Vertebral hemangiomas are benign vascular malformations of the bone with a very well-known and well-described appearance on conventional radiography, computed tomography (CT), and MRI. The incidence of hemangiomas is variable, depending on age, but has been reported to be around 11% with increasing age. Up to 30% of patients have multiple lesions.
Pathologically, these hemangiomas are considered to be postcapil-lary vascular dysembryogenetic malformations. Microscopically, they are divided into capillary, cavernous, and mixed types.24,25 The vast majority of these lesions are asymptomatic and are incidental findings on MRI examinations performed for other reasons. Less than 1% of hemangiomas become symptomatic.24
A review of 3 series describing the treatment of hemangiomas causing cord compression, with a total of 34 patients, suggests the follow ing characteristics of hemangiomas presenting with neurological symptoms (cord compression or radiculopathy): 22 of 34 patients (65%) had holovertebral (body, pedicles, and laminae) involvement, 8 of 34 (23.5%) had partial body and pedicle/posterior element involvement, and 4 of 34 (11.8%) had involvement of the body only. The majority (25 of 34, or 73.5%) were women. Young adults formed a large portion of patients presenting with cord compression and/or radiculopathy. The majority of lesions (17 of 23 in two series, or 74%) were in the thoracic spine.24-26 Fox et al. noted that neck or back pain often preceded the neurological symptoms and that thoracic myelopathy was the most common neurological presentation. An additional known risk factor for development of neurological symptoms is pregnancy, with symptoms developing in the third trimester,25 perhaps owing to the role of estrogen and/or increased venous pressure due to abdominal disten-tion and pressure of the growing uterus on the venous structures. The mechanism for cord compression can be epidural extension of the lesion from the bone (vertebral body or posterior elements) into the spinal canal, expansion of the bony vertebra by the hemangioma, a pathological fracture of the vertebra, epidural hematoma from bleeding from the lesion, or compression by enlarged feeding arteries or draining veins.25 Djindjian et al.14b divided vertebral hemangiomas into three groups based on clinical and imaging characteristics:
The type A vertebral hemangiomas present with signs and symptoms of cord compression. Imaging demonstrates extraosseous extension of the lesion, usually related to a fracture (insufficiency fracture) due to the presence of the lesion weakening the vertebral body (Figure 16.5). Angiography demonstrates dense opacification of the vertebral body via enlarged osseous (somatic) branches of normal-sized intercostal/ segmental arteries. The appearance of the lesion in the vertebral body is described as dense pools of contrast appearing in the midarterial phase and persisting into the venous phase.
Therapy: The usual treatment for these lesions consists of preoperative embolization of the lesion with particles and/or NBCA and operative decompression of the spinal cord/canal, possibly with resection of the lesion and spinal reconstruction and stabilization (Figure 16.5). Doppman et al.24 made the important observation that even when there is epidural extension, the lesion does not penetrate the dura but is confined by the periosteum, which results in the characteristic bilobed posterior margin of these lesions, indented centrally by the posterior longitudinal ligament.
An additional treatment option in these patients, in whom timely treatment is a medical necessity, is the technique of percutaneous transpedicular injection of ethanol, which Doppman et al.24 used successfully in the treatment of 11 patients. All the patients in this series had appropriate cross-sectional imaging workup. The vascularity of the lesions was determined by doing a CT scan with injection of iodi-nated contrast medium through arterial catheters placed selectively in the segmental arteries at the appropriate vertebral level.
With current imaging technology, it is possible that dynamic contrast-enhanced CT or MR images may be adequate in this regard. The needles were placed percutaneously through the pedicle, with the tip of the needle usually positioned at the vertebropedicular junction (these lesions invariably had posterior extension and/or involvement of the posterior elements). Initially, contrast material was injected through the needles, and a CT scan was performed to demonstrate opacifica-tion of the lesion. Subsequently, dehydrated ethanol opacified with metrizamide powder was forcefully injected. Because of the pain associated with ethanol injection, MAC anesthesia was recommended. For lower thoracic and upper lumbar lesions, the artery of Adam-kiewicz was identified to ensure that it did not arise at the same level. Doppman et al. recommended an ethanol volume of less than 15 mL, since higher volumes were associated with subsequent avascular necrosis and compression fractures of the treated vertebrae.24 Their recommendation was that the injection of ethanol be stopped when no blood could be aspirated from the needle, or when the volume reached 15 mL. In this series of patients, five had complete and five had partial relief of symptoms (one with no relief). Improvement of symptoms began within 1 or 2 days. Prior to discharge MRI was performed, and the images demonstrated nonenhancement and shrinkage of the lesions.
Vertebral hemangiomas of type B are associated with local pain and tenderness over the involved vertebral body, and/or radicular signs. Imaging does not reveal any extraosseous extension. The angiographic appearance is similar to that of type A lesions.
Therapy: The type B lesions are generally large. The first step in their evaluation is to exclude the more common causes of back pain, with the help of imaging and physical examination.25 Imaging further helps to exclude involvement of the posterior element, cortical disruption, and epidural spread of the lesion. In the absence of these findings, percutaneous vertebroplasty with poly(methyl methacrylate) (PMMA) is probably the treatment of choice. Other treatment options include en-dovascular transarterial embolization of the lesion by means of particles, NBCA, or ethanol. Embolization has been reported to be effective
Figure 16.5. (A) Fast spin echo T2-weighted image shows a vertebral body hemangioma with spinal canal stenosis and cord compression due to ex-traosseous extension. (B) Contrast-enhanced T1-weighted image shows the enhancing extraosseous epidural extension of the hemangioma with cord compression (arrows). (C) Selective angiogram of a left intercostal artery shows a hypervascular vertebral body with blood supply through perforating somatic branches of the intercostal artery. (D) Preoperative/PVA particle embolization through a microcatheter, which was placed coaxially through the diagnostic catheter. A fibered coil has been placed distal to the origin of somatic branches within the intercostal artery (arrow) to flow direct PVA particles preferentially into the feeding pedicles. The control angiogram shows a nearly complete devascularization. The patient received a high dose of corticosteroids prior to the procedure.
in 60 to 100% of cases.25 Percutaneous injection of opacified ethanol was described by Doppman et al.24 but for the treatment of type A lesions.
Reizine et al.27 suggested that if a painful lesion is located in the cervical or lumbar spine, without involvement of the posterior elements or cortical disruption, these lesions could be considered to be nonevo-lutive (without potential for future growth causing cord compression). On the other hand, a painful lesion located in the thoracic spine (especially in a young female) and demonstrating involvement of the posterior elements, or cortical disruption, or soft tissue extension should be considered to be an evolutive lesion, with serious potential for future cord compression.
Was this article helpful?
Deal With Your Pain, Lead A Wonderful Life An Live Like A 'Normal' Person. Before I really start telling you anything about me or finding out anything about you, I want you to know that I sympathize with you. Not only is it one of the most painful experiences to have backpain. Not only is it the number one excuse for employees not coming into work. But perhaps just as significantly, it is something that I suffered from for years.