Background context: Combining anterior release and interbody fusion with posterior instrumented fusion is an accepted treatment for severe rigid spinal deformity. Video-assisted thoracoscopic surgery (VATS) and mini-open thoracoscopically assisted thoracotomy (MOTA) are two minimally invasive approaches to the thoracic spine. Both reduce surgical trauma, improve cosmesis and provide effective exposure for release and fusion. Published data and the authors' surgical experience have demonstrated that both techniques are equivalent in degree of release to traditional open thoracotomy, but no comparison between these two minimally invasive alternatives has been published to our knowledge.
Purpose: This study compared MOTA and VATS under the hypothesis that both result in similar corrections and comparable operative parameters when used in conjunction with posterior instrumented fusion.
Study design/setting: Retrospective chart review of consecutive case series by two surgeons.
Patient sample: Twenty-one (13 female, 8 male) patients underwent MOTA and 24 patients (17 female, 7 male) underwent VATS for anterior release, discectomy and fusion prior to posterior instrumented fusion.
Outcome measures: Outcomes were measured at a minimum of 1-year follow-up and included radiographic Cobb measurements and operative parameters.
Methods: The indications for surgery included rigid and severe scoliosis or thoracic kyphosis. Data collection included preoperative demographics, number of levels released, primary curve correction, operative time and blood loss. Data were normalized per number of levels released anteriorly. Statistical analysis of results was done using a two-sample t test assuming equal variances with two-tail p values less than .05.
Results: More anterior levels were operated on average in the VATS group (6.33 vs. 4.38 levels). Curve correction per anterior level released was similar in both groups (8.7 and 8.8 degrees/level for MOTA and VATS, respectively). There was a significant difference in operative time with MOTA averaging 131.7 minutes and VATS averaging 162.8 minutes. However, a comparison of the operative time per anterior level operated, approached statistical significance in favor of VATS (33.0 vs. 28.4 minutes, p=.08). There was no significant difference in estimated blood loss during the anterior portion of the surgeries. There was a trend toward decreased blood loss per operated level favoring VATS (68.4 vs. 38.9 cc, p=.09).
Conclusions: Both approaches resulted in corrections that compare favorably with open thoracotomy. We suggest that a factor in choosing between these two minimally invasive techniques is the number of thoracic levels requiring release. For four levels or less, MOTA provides an excellent alternative to standard thoracotomy. For five or more levels, VATS provides for excellent exposure of additional levels with the advantages of less operative time and blood loss per operated level.