Establishment Of A Rabbit Model Of Pectus Excavatum

Background: Pectus excavatum (PE) is the most common chest wall malformation. The main treatments of PE are the Nuss and Ravitch procedures. Because the pathogenesis of PE remains unclear, an exact animal model has been difficult to establish. Animal models are unavailable to test new steel bars used in the Nuss procedure and to elucidate the mechanism by which PE affects pulmonary function. This study described the establishment of a rabbit model of PE. Methods: Twenty-four New Zealand white rabbits were randomized into a PE group and a control group. The animals in the PE group underwent surgery to remove a 0.5 cm long segment of the fifth to seventh costicartilage and removal of the sternum at the fifth costicartilage level. In control animals, the skin and muscle were incised and stitched into two layers. Results: Ten days after surgery, rabbits in the PE group showed gradual depression of the sternum. Over time, as rabbit weight increased, the depression of the anterior and inferior chest wall deepened and widened gradually. The deformity of the chest wall was similar at 6 and 12 weeks after surgery. Chest CT scans at 8 weeks after surgery showed that the depression extended from the cutting at the fifth costicartilage level to the spine. Three-dimensional reconstruction of the thorax showed that the depression of the sternum began at the level of fifth rib and most obvious at the level of the seventh rib. Conclusions: This rabbit model of PE was simple, less invasive, and easy to establish.