Establishment of a Rabbit Model of Rib Tethering-Induced Early-Onset Scoliosis: Insights into Lung Evaluation using Design-Based Stereology.

Abstract

Study design: Experimental Study.

Objective: To create an EOS rabbit model and use a design-based stereological method to quantitatively assess lung structure changes at 24 weeks of age.

Summary of background data: Scoliosis affects thoracic and lung development, impacting children's chest and lung growth.

Methods: EOS was induced via rib tethering in 4-week-old rabbits with ongoing CT scans and weight measures. Lungs were extracted post-fixation for volume estimation and tissue sampling, followed by microscopic analysis of lung morphology.

Results: The mean Cobb angle increased with the rabbits' growth. The EOS group showed significant decreases in total and right lung volumes. Quantitative lung stereology revealed reduced volumes of lung parenchyma and nonparenchymal tissue in all lobes. Alveolar duct volumes decreased significantly in multiple lobes, and alveolar septal volume was notably reduced in the right upper, middle, and lower lobes. Alveolar septal area decreased, and septal thickness increased in the EOS group. Alveoli numbers dropped, with variable changes in mean alveolar volume across lobes. Vascular lumen volume decreased in the right middle and lower lobes, and blood vessel and perivascular tissue volumes were significantly reduced in the right lung. Vessel diameter changes varied across lobes, with significant decreases in the right middle and lower lobes and increases in the left upper and lower lobes. Vascular endothelial surface area decreased in the left lower, right middle, and right lower lobes, with increased vessel and perivascular tissue thickness in the left upper and lower lobes compared to the right lobes.

Conclusion: The EOS rabbit model demonstrated reduced lung volume, impaired alveolarization, septal thickening, and vascular changes, indicating scoliosis's negative impact on thoracic and lung development, especially on the concave lung.