Anterior scoliosis correction (ASC)
When is this procedure indicated?
Motion-preserving Anterior Scoliosis Correction (ASC) is an innovative and effective technique that allows to extend the benefits of Vertebral Body Tethering (VBT) to those patients with scoliosis larger than 65° and/or patients who are near to or have completed the growth of the spine. The technique has been used effectively in patients with some curve patterns up to 90° of deformity (Cobb angle). Adolescent idiopathic scoliosis is the main indication for VBT, but in some selected cases the procedure could be considered in other types of scoliosis. Patients with very severe curves may need a two step procedure (first surgery for partial correction and a second operation months later to increase the final correction). The most substantial advantage of ASC is that it does not block the motion of the areas of the spine that are included in the correction.
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. For double curves, the procedure is repeated at the opposite side. 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. In ASC the surgeon may suggest to use a double row of vertebral screws so that a double cord can be implanted (which allows for larger correction and a stronger construct).
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.