Long-term Pulmonary Function After Open Anterior Thoracolumbar Surgery in Thoracolumbar/Lumbar Idiopathic Adolescent Scoliosis

Abstract

A prospectively updated, long-term case series analysis. The aim of this study was to report the effect of thoracolumbar anterior open surgery performed during adolescence on adult pulmonary function. There seems to be subclinical impairment of pulmonary function in the mid-term (2-5 years) in patients who underwent thoracotomy or thoraco-phreno-laparotomy after adolescent idiopathic scoliosis (AIS) surgery. However, long-term results when patients reach adulthood are lacking. Prospective data of pulmonary function tests (PFTs) on adult patients who underwent anterior open surgery during adolescence due to main thoracolumbar/lumbar curves were collected. Forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and the Tiffeneau index (TI: FEV1/FVC) with a 12-year minimum follow-up were recorded. These figures were compared with reference (predicted) values and preoperative data. Twenty-four patients were included. All patients had undergone a thoraco-phreno-laparotomy. None of the patients had pulmonary disease. Mean age was 15.83 years at the time of surgery and the mean follow-up was 18.26 years (12-29 years).Long-term results of the 24 operated patients (mean ± SD: FVC = 3.3 ± 0.39; FEV1 = 2.6 ± 0.38; TI = 80.3 ± 5.7) showed a similar FVC and slightly worse FEV1 than reference values (FVC = 3.4 ± 0.48; FEV1 = 3.03 ± 0.42; TI = 82.4 ± 1.3), (P = 0.21; P = 0.02; P = 0.3, respectively). Nevertheless, the values were within the normal percent-predicted range for FVC (93.5% ± 11.2) and FEV1 (91.4% ± 12.8). In 14 patients, long-term figures (median ± IQR): FVC = 3.2 ± 0.6; FEV1 = 2.54 ± 0.42; TI = 81.5 ± 11.2) were compared with preoperative values (median ± IQR: FVC = 2.9 ± 0.8; FEV1 = 2.47 ± 0.93; TI = 84.8 ± 34.2), (P = 0.08, P = 0.92, P = 0.026, respectively). Only the TI showed significant differences due to disproportionate improvement of FVC and FEV1 during the follow-up years. Thoracolumbar/lumbar AIS patients who underwent a thoraco-phreno-laparotomy during adolescence showed, in the long-term (18 years follow-up), a similar FVC compared with the reference values that was slightly superior than the values before surgery. Despite the lower FEV1 than the reference values and taking into consideration our limitations, the percent-predicted values were within the normal range, indicating no major pulmonary impairment in the long run. 4.