Research on the effects of posterior vertebral column resection on pulmonary function in the patients with severe rigid spinal deformity accompanied by respiratory dysfunction

BI Ni; XIE Jing-ming; WANG Ying-song; ZHANG Ying; ZHAO Zhi; LI Tao; LIU Zhou; SHI Zhi-yue

doi:10.3969/j.issn.2095-252X.2014.12.005

Abstract：Objective To analyze the preoperative and postoperative pulmonary function test ( PFT ) results in the patients with severe rigid spinal deformity ( excluding hemivertebra deformity ) accompanied by respiratory dysfunction who underwent posterior vertebral column resection ( PVCR ) and to summarize the variation rules.Methods From January 2004 to January 2009, 24 patients with severe rigid spinal deformity ( excluding hemivertebra deformity ) and obvious respiratory dysfunction were enrolled. Their mean age was ( 18.9±8.0 ) years old ( range:11-45 years ). The average preoperative scoliotic Cobb’s angle was ( 110.1±14.6 ) ° ( range:94°-170° ) and the average preoperative kyphotic Cobb’s angle was ( 80.6±29.2 ) ° ( range:42°-160° ). All the patients underwent PVCR. They were divided into moderate ( 40%-60%) impairment group and severe (<40%) impairment group according to the preoperative vital capacity ( VC ). The PFT parameters were measured preoperatively and at 2 weeks, 3 months, 6 months, 1 year and 2 years after the operation, including VC, VC percentage of the measured value and the predicted value ( VC%), forced vital capacity ( FVC ), FVC percentage of the measured value and the predicted value ( FVC%), forced expiratory volume in 1 second ( FEV1 ) and FEV1 percentage of the measured value and the predicted value ( FEV1% ). The relationship between the postoperative recovery period and the PFT parameters was analyzed, as well as the relationship between the postoperative recovery period and the preoperative and postoperative subjective symptom improvement ( respiratory distress, pulmonary inflammation, exercise capacity and quality of life ). Results All the patients were followed up for 24 months. The FVC, FVC%, FEV1 and FEV1%were ( 0.92±0.04 ) L, ( 26.55±0.67 ) %, ( 0.98±0.06 ) L and ( 25.48±0.41 ) % at 2 weeks after the operation in severe impairment group, which were obviously lower than ( 1.13±0.06 ) L, ( 28.27±0.55 ) %, ( 1.04±0.06 ) L and ( 27.42±0.36 ) %preoperatively ( P<0.05 ). The FVC, FVC%, FEV1 and FEV1%were ( 1.28±0.06 ) L, ( 38.83±1.00 )%, ( 1.05±0.03 ) L and ( 35.43±0.36 )%at 2 weeks after the operation in moderate impairment group, which were obviously lower than ( 1.42±0.04 ) L, ( 40.33±0.79 )%, ( 1.33±0.04 ) L and ( 37.38±0.47 )%preoperatively ( P<0.05 ). The arterial blood gas ( ABG ) analysis showed abnormal results. The PFT parameters at 2 weeks after the operation were obviously lower than that preoperatively, and the differences between them were statistically signiifcant ( P<0.05 ). At 3 months after the operation, the PFT parameters began to increase gradually, but still lower than the preoperative parameters. At 1 year after the operation, the PFT parameters were higher than the preoperative parameters and the differences between them were not statistically signiifcant ( P>0.05 ). However, subjective symptom improvement was noticed in 96%of the patients. The Metabolic Equivalent of Energy ( MET ) grade was improved after the operation, and the ABG analysis and chest X-ray showed no abnormality. The FVC, FVC%, FEV1 and FEV1%were ( 1.48±0.03 ) L, ( 33.67±0.49 )%, ( 1.28±0.03 ) L and ( 31.53±0.41 )%in severe impairment group and ( 1.56±0.06 ) L, ( 42.05±0.38 )%, ( 1.43±0.04 ) L and ( 39.32±0.40 )%in moderate impairment group at 2 years after the operation. The pulmonary function was obviously improved in all the patients. The VC was recovered by 17.1%, FVC by 18.7%and FEV1 by 14.4%, and the differences between them were statistically signiifcant ( P<0.05 ). Subjective symptom improvement was noticed in all the patients, and the ABG analysis and chest X-ray showed no abnormality. There was a positive correlation between the recovery time and rate of change of the postoperative PFT parameters and improvement rate of the subjective symptoms. Conclusions The pulmonary function in the patients with severe rigid spinal deformity becomes worse at 2 weeks after PVCR. With the extension of recovery time, it will return to preoperative baseline at 1 year after the operation and be signiifcantly improved at 2 years after the operation, especially in the patients with severe ventilatory disorders. The PFT parameters at 2 years after PVCR are higher than the preoperative parameters. What is more, subjective symptom improvement is noticed in most patients at 1 year after the operation and the ABG analysis and chest X-ray show no abnormality. Signiifcant subjective symptom improvement is noticed in almost all the patients at 2 years after the operation, which is crucial for the improvement of the quality of life.