Vertebral body tethering (VBT)
When is this procedure indicated?
The Vertebral Body Tethering (VBT) is a very effective surgical technique to correct scoliosis in growing adolescents. Patients with a scoliosis curve between 35 and 65 degrees (Cobb angle), who have sufficient growth left in the spine can benefit from this procedure. Adolescent idiopathic scoliosis is the main indication for VBT, but in some selected cases the procedure could be considered in other types of scoliosis. For patients with larger angles or who have completed or are approaching the end of spinal growth, a similar technicque (motion-preserving anterior scoliosis correction, also known as ASC) can be used.
How is it performed?
A 15 to 10 cm on the side of the trunk (for single curves) is performed in order to access the spine. The surgeon places implants (titanium screws) in the vertebral bodies which will serve as anchors for correction of the deformity from its convex side. A flexible cord made of a synthetic polymer - called a tether - connects the screws, is pulled taut in order to correct the deformity and is secured at each screw after the segmental correction. During surgery the curve is brought down typically to 10 to 25 degrees (depending on the amount of spinal growth left in the patient). The tether allows for selective growth of the vertebrae on the shortest side (the concavity). In this way, during the rest of the spinal growth the curve will progressively correct further.
After surgery the patient is observed in intensive care for 12 to 24 hours. A chest drain is in place for 24-48 hours to maintain lung expansion. Most patients do not require blood transfusions for this procedure. The patient will be sent to either the Intensive Care Unit at the end of the surgery. On second postoperative day most patients will get out of bed and start walking with the assistance of a therapist. Upon discharge patients are able to walk and climb stairs. No brace is required postoperatively in most cases. The patient will avoid bending and twisting forcefully in the early post-operative period. Sports are allowed 2 months after surgery.
Collapsed lung (pneumothorax or hemothorax), hematoma, lung infection are relatively uncommon complications. Neurological complications, bone fractures, wound or spinal infection are very uncommon complications.
Overcorrection, adding-on (extension of the scoliosis beyond the vertebrae included in the procedure), loosening of the vertebral body tether, tether breakage, progression of deformity are uncommon but possible long-term complications.