P99. Preserving pulmonary function in mini open thoracoscopic assisted vertebral body tethering

BACKGROUND CONTEXT There are two ways to approach the spine using vertebral body tethering in adolescent idiopathic scoliosis correction surgery, mini open thoracoscopic assisted and thoracoscopic vertebral body tethering (VBT). This study focuses on preoperative and 2-year followup pulmonary function tests for mini open thoracoscopic assisted vertebral body tethering surgical cases. Currently there is evidence that pulmonary function does not decrease in a thoracoscopic approach, but it is unclear how pulmonary function is affected by a mini open thoracoscopic assisted approach to VBT surgery. PURPOSE To provide evidence that mini-open thoracoscopic assisted vertebral body tethering maintains pulmonary function at 2-year followup. STUDY DESIGN/SETTING Retrospective review at a single institution. PATIENT SAMPLE A total of 114 patients who underwent mini open thoracoscopic assisted vertebral body tethering surgery with 2-year followup were included in this study. OUTCOME MEASURES Primary outcomes included forced vital capacity (FVC), forced expiratory volume during the first second (FEV1), forced expiratory flow during the middle half of the FVC (FEF25-75%), peak expiratory flow (PEF), forced expiratory time (FET200%), forced inspiratory vital capacity (FIVC), total lung capacity (TLC), vital capacity (VC), and respiratory volume (RV). METHODS A retrospective review of patients who underwent mini open thoracoscopic assisted VBT surgery. Preoperative and 2-year follow up pulmonary function tests were performed in order to assess the pulmonary risks of VBT. T tests were used to determine significant differences in pulmonary function preoperatively and two years post surgery. RESULTS Pulmonary outcomes analysis revealed there were no significant decrease from preoperative to postoperative pulmonary function: FVC predicted (3.51 vs 3.53, p=0.92), FVC Pre (3.01 vs 3.02, p=0.933), FEV1 Predicted (3.11 vs 3.27, p=0.349), FEV1 Pre (2.55 vs 2.48, p=0.667), FEV1/FVC Predicted (88.34 vs 88.88, p=0.604), FEV1/FVC Pre (77.32 vs 84.89, p=0.148), FEF25-75 Predicted (3.64 vs 3.81, p=0.494), FEF25-75 Pre (2.57 vs 2.59, p=0.919), ISOFEF25-75% Pre (2.65 vs 2.79, p=0.822), FEF75-85% Pre (1.41 vs 1.36, p=0.93), PEF Predicted (6.21 vs 6.79, p-0.145), PEF Pre (5.42 vs 5.24, p-0.737), FET100% Pre (6.13 vs 6.23, p=0.915), FIVC Predicted (3.3 vs 3.32, p=0.963), FIVC Pre (2.72 vs 2.2, p=0.073), TLC (4.29 vs 5.56, p-0.233), VC (3.93 vs 3.19, p-0.781), RV (0.76 vs 1.31, p-0.258). CONCLUSIONS Mini open thoracoscopic assisted VBT maintains pulmonary function outcomes from baseline to 2-year followup. This can be another approach option for vertebral body tethering surgery. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs. There are two ways to approach the spine using vertebral body tethering in adolescent idiopathic scoliosis correction surgery, mini open thoracoscopic assisted and thoracoscopic vertebral body tethering (VBT). This study focuses on preoperative and 2-year followup pulmonary function tests for mini open thoracoscopic assisted vertebral body tethering surgical cases. Currently there is evidence that pulmonary function does not decrease in a thoracoscopic approach, but it is unclear how pulmonary function is affected by a mini open thoracoscopic assisted approach to VBT surgery. To provide evidence that mini-open thoracoscopic assisted vertebral body tethering maintains pulmonary function at 2-year followup. Retrospective review at a single institution. A total of 114 patients who underwent mini open thoracoscopic assisted vertebral body tethering surgery with 2-year followup were included in this study. Primary outcomes included forced vital capacity (FVC), forced expiratory volume during the first second (FEV1), forced expiratory flow during the middle half of the FVC (FEF25-75%), peak expiratory flow (PEF), forced expiratory time (FET200%), forced inspiratory vital capacity (FIVC), total lung capacity (TLC), vital capacity (VC), and respiratory volume (RV). A retrospective review of patients who underwent mini open thoracoscopic assisted VBT surgery. Preoperative and 2-year follow up pulmonary function tests were performed in order to assess the pulmonary risks of VBT. T tests were used to determine significant differences in pulmonary function preoperatively and two years post surgery. Pulmonary outcomes analysis revealed there were no significant decrease from preoperative to postoperative pulmonary function: FVC predicted (3.51 vs 3.53, p=0.92), FVC Pre (3.01 vs 3.02, p=0.933), FEV1 Predicted (3.11 vs 3.27, p=0.349), FEV1 Pre (2.55 vs 2.48, p=0.667), FEV1/FVC Predicted (88.34 vs 88.88, p=0.604), FEV1/FVC Pre (77.32 vs 84.89, p=0.148), FEF25-75 Predicted (3.64 vs 3.81, p=0.494), FEF25-75 Pre (2.57 vs 2.59, p=0.919), ISOFEF25-75% Pre (2.65 vs 2.79, p=0.822), FEF75-85% Pre (1.41 vs 1.36, p=0.93), PEF Predicted (6.21 vs 6.79, p-0.145), PEF Pre (5.42 vs 5.24, p-0.737), FET100% Pre (6.13 vs 6.23, p=0.915), FIVC Predicted (3.3 vs 3.32, p=0.963), FIVC Pre (2.72 vs 2.2, p=0.073), TLC (4.29 vs 5.56, p-0.233), VC (3.93 vs 3.19, p-0.781), RV (0.76 vs 1.31, p-0.258). Mini open thoracoscopic assisted VBT maintains pulmonary function outcomes from baseline to 2-year followup. This can be another approach option for vertebral body tethering surgery.