By Narendra Bodhey
Asymptomatic or incidental in almost 15% of the population, vertebral haemangioma (VH) is the second most common cause of spinal problems after osteoporosis.
The VH, an expansible lesion, is particularly important due to its notorious behaviour in terms of recurrence unless eliminated extensively. It causes backache if not associated with intraspinal soft tissue compressing the neural elements. Patients present with neurodeficit when there is intraspinal extension of the soft tissue.
The neurodeficit is dictated by the level and extension of spinal cord compression.
The diagnosis of VH could start with a plain skiagram of the affected spine. Therein, multiple vertical striations are seen in the expanded vertebra giving it a “jail bar” or a “corduroy” appearance. The same on an axial computed tomography (CT) scan are seen as small spots – “polka dot” sign. With Magnetic Resonance Imaging (MRI), the affected vertebra shows hyperintense signal on T1WI and iso-to-hyperintense signal on T2WI.
The associated soft tissue enhances with administration of intravenous contrast. The MRI is the best investigation to clinch the diagnosis and depict the extension of the disease and neural compromise.
The treatment, until recently, was just radiotherapy, which had risks of arachnoiditis and other complications. However, surgery is needed to relieve the compression on the spinal cord. The surgery in such cases requires significant intraoperative blood transfusion.
However, with the advent of endovascular embolization procedures, blood loss has been considerably reduced. The interventional radiologist positions a suitable catheter into the artery (mostly a branch of intercostal artery or a lumbar artery) by a retrograde femoral artery approach. The embolization material could be either simple Gelfoam pieces or polyvinyl alcohol (PVA) particles.
Vertebroplasty, strengthening of the vertebra, has revolutionised the treatment of VH. It involves percutaneous instillation of bone cement through biopsy needles placed after a local anaesthesia. The cement is a mixture of methyl methacrylate and polymethyl methacrylate and has many advantages.
First, it strengthens the vertebra that has been weakened by the haemangiomatous tissue, rarifying the vertebral bone. Secondly, its exothermic nature destroys the haemangioma per se, thereby eliminating the pathology and causing some shrinkage of soft tissue component. Third, the damage is also done to the tiny nerve endings that are responsible for producing pain. Fourth, the procedural morbidity is very low in the hands of an experienced radiologist, which allows the patient to have minimal hospital stay and return to his/her routine life.
It should be noted that this procedure, like any other, is not without complication. There could be increase in the neuro deficit if the cement leaks into the spinal canal. Another important issue is recurrence. Even minimal haemangiomatous tissue left unfilled with cement leaves room for recurrence of the lesion.
In case it is not possible to completely fill the haemangiomatous vertebra with bone cement, ethanol injection can be performed, especially if the posterior elements are involved. It is good for ablating the soft tissue component in the paravertebral space.
However, if there is significant cord compression by the intra-spinal soft tissue, surgery may be needed in a few cases to relieve the compression.
At our institute (SCTIMST, Kerala, India), we follow a protocol for comprehensive management of VH. Those VH that have a minimal soft tissue component and relatively less involvement of posterior elements, undergo only percutaneous vertebroplasty.
Those patients that are considered for surgical decompression either due to existing large intraspinal soft tissue or a possible intra-procedural leak of cement (due to posterior cortical break of vertebral body) undergo an endovascular embolization, followed by vertebroplasty and then surgery. This minimises the intro-operative blood loss. Patients having an extensive paravertebral soft tissue undergo an additional ethanol injection under CT-guidance.
For the present moment, this treatment seems to be the best. However, it is a matter of follow up that will reveal if the disease recurs in spite of all these efforts.
Narendra Bodhey is Associate Professor, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Kerala, India.