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Radiology
Case
30: Contributed by Dr. Nishant Kumar
Other Cases
A 25-year-old man presented with complaints of paraparesis since two months. Plain radiographs and MRI of the dorso-lumbar spine were done. These showed an aggressive D9 vertebral hemangioma. with a significant soft tissue component (Figs 1 & 2).
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Transarterial embolization of the hemangioma was done using polyvinyl alcohol foam (PVA) particles followed by coil embolization of the proximal arterial trunk. Following this, there was complete recovery of the deficit.
The patient presented again a year later with low dorsal backache. After localization of the tenderness to the level of the hemangiomatous vertebra, the lesion wad treated by transpedicular vertebroplasty. Complete regression of symptoms was achieved after the procedure. (Figs 3,4,5)
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Six
months later, paraparesis recurred.. He was then subjected to CT guided alcohol
ablation (Fig. 6 & 7) of the lesion. This resulted in transient worsening of symptoms
with complete recovery thereafter. The patient continues to be asymptomatic over
the last five years.
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DISCUSSION:
Introduced by a French Neuroradiologist Herve Deramond in 1987, vertebroplasty is a simple, minimally invasive percutaneous technique of plastic reconstruction of the weakened vertebra by injecting bone cement resulting in pain relief & restoration of biomechanical strength.
Indications : These include osteoporosis, primary tumors, osteolytic mtastasis, painful aggressive hemangioma (with or without epidural component) and trauma. At our institution, depending upon presence of neurological deficit, the type of presentation (whether first presented with pain or neurological deficit) and whether there is recurrent episode of lesion or not , a protocol has been set (Fig.8 )
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PMMA
works at two fronts: Analgesic effect (in situ immobilization of fracture, destruction
of nerve endings due to exothermic reaction) and anti-tumor effect (Local toxicity
of PMMA).
Contraindications: (No absolute contraindication)
1.
Breach in the posterior cortex of the vertebral body 2. Epidural extension 3.
Vertebra plana
Preprocedural Evaluation:
Radiograph:
This is to evaluate the degree of vertebral compression, presence of osteolysis,
extent of pedicular involvement , presence of fracture or cortical destruction.
MRI: Extent & "activity" of the lesion and evaluation of the fracture, Examination
under fluoroscopy for tenderness
Procedure
:
Material (Vertebroplasty Kit) Fig 9
Bone Cement
I. Powder
(PMMA)
II. Liquid (MM)
1cc Leur Lock Syringes/ Injecting Devices
Bone
Biopsy needle (11/13/15 G)
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Approach: [ Fig.10]
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UNILATERAL/
BILATERAL
Posterolateral : If the posterior elements are destroyed; aAntero
later cervical and transoral (C1, C2). During the approach to the pedicle (after
injecting local anaesthetic agent in deep tissues including periosteum ), the
vertebroplasty needle is targeted to the upper outer quadrant of pedicle and then
the tip is guided medially downwards while having closely monitoring the progress
of the needle on the lateral view. Finally, the needle is parked just posterior
to anterior. cortex of vertebral .body.
Preparation:
PMMA
is mixed with liquid methyl methacrylate The polymer is mixed by shaking vigorously
in the container provided until a toothpaste like consistency Is achieved.
The
polymerization time of methyl methacrylate can be extended by cooling the mixture
in an iced bath of sodium chloride solution.
Injection:
Multiple
1 cc syringes are filled with PMMA & used for injection in sequence. Slow, continuous
injection of the cement under fluoroscopy in the lateral projection with intermittent
fluoroscopy in the frontal projection is done. The end point: is the reaching
of the cement up to the posterior quarter of the vertebral body.
Postoperative
Bed
rest for two hours. Post procedure plain CT Scan, and analgesics.
Outcome:
Pain is the first symptom to disappear. This is followed by gradual improvement
in neurological deficit that may be present.
Due to pain relief, mobility improves
ion 24-48 hours.
Complications:
Relatively safe, but the cmplications
in malignant lesions are higher Needle related: pedicular fracture, cord injury,
injury to the carotid artery, jugular vein, pleura etc may also occur.
PMMA
related :pulmonary embolism, leakage into the spinal canal/ neural foramina are
also known complications.
Conclusions:
Vertebroplasty is a safe
& effective technique in painful & non infective lesions of the spine. Special
care to be taken while dealing with malignant lesions. It is safe if done under
high quality, preferably biplane fluoroscopic guidance.