Perioperative changes in pulmonary function after anterior scoliosis instrumentation:: Thoracoscopic versus open approaches

Study Design. A prospective evaluation of pulmonary function in patients with adolescent idiopathic scoliosis undergoing surgical correction. Objective. To determine if a minimally invasive thoracoscopic approach had less postoperative pulmonary function impairment compared to open anterior instrumentation for idiopathic scoliosis. Summary of Background Data. Prior studies suggest that open anterior scoliosis surgery causes an initial decrease in pulmonary function that resolves by 2 years after surgery. However, the effect of thoracoscopic instrumented scoliosis correction on pulmonary function is unknown. Methods. Fifty-four patients with AIS undergoing anterior spinal instrumentation and fusion at the authors' institutions were evaluated with pulmonary function tests assessing forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). Patients were evaluated before surgery, as well as 3 months and 1 year after surgery. There were 2 groups of patients: in one group, a thoracoscopic technique was used to visualize and instrument the anterior spine ( n = 31); and in the other, an open single or double thoracotomy was used ( n = 23). Results. Three months after surgery, the thoracoscopic group had a significantly smaller decline in FVC than the thoracotomy group; at 1 year after surgery, the thoracoscopic group had recovered, while FVC remained reduced in the open group. The decline in FEV1 from before surgery to 3 months after surgery was similar between groups; however, by 1 year after surgery, the thoracoscopic group had more recovery of pulmonary flow than the thoracotomy group. Conclusions. The thoracoscopic approach causes a smaller decline in pulmonary function 3 months and 1 year after surgery as compared to the more invasive technique of open thoracotomy for anterior spinal instrumentation for correction of adolescent idiopathic scoliosis.