Value of preoperative pulmonary function test in flaccid neuromuscular scoliosis surgery

Study Design.: Retrospective study. Objective.: To evaluate the prognostic value of preoperative pulmonary function test (PFT) for postoperative pulmonary complications and to identify the operability associated with severely decreased forced vital capacity (FVC) (<30%) status in flaccid neuromuscular scoliosis. Summary of Background Data.: The preoperative PFT, especially more than 30% FVC, is known as a critical factor for the operability of flaccid neuromuscular scoliosis. But only one study reported that patients with pre-existing respiratory failure on nocturnal noninvasive ventilation can undergo an operation for deformity correction without mortality and severe complications. Methods.: A total of 74 patients (45 male and 29 female) presented with flaccid neuromuscular scoliosis. For all patients, preoperative PFTs were evaluated and subdivided into three groups (<30% FVC, 30%-50% FVC, and >50% FVC). Then postoperative pulmonary complications, pneumothorax, pneumonia, atelectasis, prolonged ventilator care in the intensive care unit (more than 72 hours), and postoperative tracheostomy were evaluated. Results.: Among these patients, 59 had muscular dystrophy; 5, spinal muscular atrophy; 2, cerebral palsy; and 8, others. The mean age at surgery was 16.8 years (range, 5-32 years). The mean preoperative Cobb angle was 54.6° (16°-135°). The overall postoperative pulmonary complication rate was 31% (23 complications in 74 patients). The less than 30% FVC group had 6 complications among 18 patients; the 30% to 50% FVC group had 7 complications among 18 patients; and the more than 50% FVC group had 10 complications among 38 patients. There were no deaths during the perioperative period. There is no statistical difference between the three groups (P = 0.6195). Conclusion.: Patients with flaccid neuromuscular scoliosis can undergo an operation for deformity correction regardless of the severely decreased pulmonary function.