The Role of Preoperative Pulmonary Function Tests in the Surgical Treatment of Scoliosis

Study Design. A retrospective study on the correlation between preoperative pulmonary function tests, preoperative pulmonary symptoms, and postoperative pulmonary complications. Objective. To evaluate the incidence of immediate postoperative pulmonary complications and their correlation to pulmonary function tests, preoperative pulmonary symptoms, and surgical approaches. Summary of Background Data. The pulmonary function of patients with scoliosis is likely to be abnormal, whereas surgical procedures may lead to further deterioration and postoperative pulmonary complications. Evaluation of the pulmonary symptoms and pulmonary function before surgery is helpful to predict and avoid postoperative pulmonary complications by selecting the appropriate surgical approach. Methods. This study reviewed 298 scoliosis patients (107 male, 191 female) who underwent anterior and/or posterior operation. The mean age of the patients was 16.4 years (range 6–62 years). The average coronal Cobb angle was 73.26° (range 45–141°). Preoperative pulmonary function tests of 115 cases were normal, whereas the other 183 cases were abnormal. Seventeen cases had preoperative pulmonary symptoms and 3 of them had normal preoperative pulmonary function tests. Seventy-nine cases received transthoracic surgery, and 19 cases had postoperative pulmonary complications, including postoperative ventilation support in 6 cases, atelectasis in 4 cases, hydrothorax in 2 cases, pneumothorax in 3 cases, pneumonia in 3 cases, and hypoxemia in 1 case. Of these 19 patients, 12 patients received anterior transthoracic procedure. When the patients with abnormal pulmonary function tests were divided into 3 groups: 1) 60% ≤ forced vital capacity ratio < 80%; 2) 40% ≤ forced vital capacity ratio < 60%; and 3) forced vital capacity ratio < 40%, the incidence of postoperative pulmonary complications were 2.72% (3 out of 110), 7.40% (4 out of 54) and 31.60% (6 out of 19), respectively. Results. There was significant correlation between abnormal preoperative pulmonary function tests and preoperative pulmonary symptoms (P = 0.0086). No significant correlation was found between preoperative pulmonary symptoms and postoperative pulmonary complications (P = 0.5164). There was a trend that the postoperative complications increased with the deterioration of pulmonary function. The correlation between postoperative pulmonary complications and the surgical approach was statistically significant (P = 0.0000); the incidence of postoperative pulmonary complication of transthoracic procedure was 18 times as that of posterior approach. No significant difference was noted regarding ages, preoperative coronal Cobb angles, and preoperative pulmonary function between these 2 groups. There was no significant correlation between preoperative pulmonary symptoms and postoperative complications. Conclusions. The incidence of postoperative pulmonary complications increased with the deterioration of pulmonary function tests. The posterior procedure had a very low incidence of postoperative pulmonary complications, but a transthoracic procedure increased the complications significantly. Preoperative pulmonary symptoms usually predicted abnormal results of pulmonary function tests but had no correlation with postoperative pulmonary complication.