Adolescent Idiopathic Scoliosis: A Cross-Sectional Study.

ABSTRACT

Objective: Adolescent idiopathic scoliosis (AIS) can lead to right heart dysfunction. Inferior vena cava (IVC) diameter is an essential parameter of the right-heart function, but the relationship between scoliosis and the IVC diameter has not been established. This study aimed to investigate the correlation between the IVC diameter and the severity of AIS. Methods: This retrospective study examined the data from patients admitted to Peking Union Medical College Hospital between January 2000 and June 2014 with a diagnosis of AIS. A preoperative spine full-length standing X-ray was collected. The IVC diameter was measured during the expiration phase as a routine examination. Results: Among the 339 included patients, 269 had thoracic curves, and 311 had at least a thoracic or thoracolumbar curve. Significant correlations between the diameter of IVC and the coronal Cobb angle of main thoracic curves (r=0.142, P = .015) and thoracolumbar curves (r=0.580, P = .015) were observed. Regarding the possible confounding factors, the IVC diameter was also significantly correlated to body weight (r=0.327, P < .001) and body height (r=0.134, P = .014). In the partial correlation analysis correcting for body weight and height, the IVC inner diameter was correlated to the Cobb angle of the thoracic curve (r=0.172, P = .003) and the larger curve of either the thoracic or thoracolumbar curve (r=0.190, P = .001). Discussion: The result of this study implies that even in patients with mild scoliosis, there might already be underlying right heart function changes. Heart function should be taken into more consideration for AIS paitents. For patients with higher IVC diameters, a more throught cardiology assessment should be performed. Conclusion: The IVC diameter is positively correlated with the Cobb angle of thoracic curves or the larger one of thoracic or thoracolumbar curves in patients with AIS.