Study Design: Compartative cohort study.

Objective: To compare the safety and efficacy of conventional posterior instrumented fusion versus thoracoscopic instrumented fusion for the surgical treatment of King Type III adolescent idiopathic scoliosis.

Methods: The results of 34 consecutive patients with King type 3 scoliosis treated with one of the above techniques were analyzed independantly. Twenty-two patients underwent posterior spinal fusion (PSF) and instrumentation (Moss-Miami). Twelve patients had thoracoscopic fusion (TF) and instrumentation (Eclipse).

Results: Baseline demographics (age at menarche and surgery, pre-operative Cobb angles in coronal and sagittal planes), estimated blood loss at surgery and duration of parenteral analgesia did not differ between the two groups. PSF patients had significantly higher transfusion requirements (p=0.032). Operative time (p = 0.0001), ICU stay (p = 0.005), and hospital stay (p = 0.037) were longer in TF cases. There were no complications in PSF patients. Complications in TF patients included lobar collapse (1 patient) and scapula winging (1 patient). Improvement in scoliosis among PSF patients averaged 75% (1 week), 70% (6 months), and 65% (1 year). In TF patients, mean improvement in scoliosis was 66% (1 week), 62% (6 months), and 62% (1 year). The differences between the two groups in terms of scoliosis improvement were not significant. Curves with apex at T8 or higher had better correction of scoliosis (p = 0.05). The sagittal alignment (thoracic kyphosis and lumbar lordosis) after surgery was similar between the two groups at 1 week, 6 months, and 1 year post-operatively.

Conclusion: The efficacy of thoracoscopic anterior fusion and instrumentation is similar to standard posterior instrumented fusion. The advantages of the thoracoscopic technique are the avoidance of a long posterior midline scar, and lower transfusion requirement. A longer operative time, ICU and hospital stay was attributed to the steep learning curve of this endoscopic technique.

Video-assisted thoracoscopic surgery (VATS) has been in use since the 1980s for surgery of the spine. Initially it was used for anterior release of the thoracic spine in order to facilitate posterior instrumentation. With increasing experience, it has been applied to perform definitive correction and instrumentation. Video-assisted thoracoscopic spine surgery allows the surgeon to perform anterior thoracic spine operations with fewer levels of instrumentation, reducing the crankshaft effect and removing the morbidity associated with thoracotomy. From 1996 to November 2000, our center performed 19 such operations. 18 of them were completed successfully endoscopically and one was converted to an open procedure. An initial group of 10 patients underwent thoracoscopic anterior release and fusion followed by same day posterior instrumentation and fusion. Subsequently, 6 patients underwent anterior discectomies, fusion with instrumentation via thoracoscopic approach.

For the initial 10 patients, the average operative time was 190 minutes. The average post-operative correction was 62 % and blood loss was 350 mLs. For the 6 patients who underwent anterior discectomies, fusion and instrumentation via the thoracoscopic approach, the average operative time was 360 minutes; average post-operative correction was 70% and blood loss was 400 mLs.

Complications encountered were minor and included one case ofcontralateral pneumothorax, one patient complained of transient limb numbness which resolved within 6 weeks. It is our conclusion that thoracoscopic anterior spinal surgery, though with learning curve, a safe and effective procedure.