Feasibility of Magnetic Compression-Mediated Transection of Rabbit Xiphoid Cartilage: A Simulation Study for Tracheobronchial Remnant-Type Congenital Esophageal Stenosis.

BACKGROUND: Tracheobronchial remnant (TBR)-type congenital esophageal stenosis (CES) is a rare infantile anomaly characterized by ectopic tracheobronchial cartilage within the esophageal wall. Magnetic compression devices are effective for soft-tissue approximation, but their ability to transect cartilage remains unproven. This study assessed magnetic compression-mediated transection of rabbit xiphoid cartilage. METHODS: Eighteen rabbits were divided into control, sham-operated, and experimental groups (n = 6 each). Experimental rabbits received magnetic compression devices to compress the xiphoid cartilage; sham-operated rabbits underwent surgery without device placement. Radiography monitored angular changes and time to transection. After transection in the experimental group, cartilage specimens were collected from both experimental and sham groups for histopathology, transmission electron microscopy (TEM), immunohistochemistry, qPCR, and ELISA (measuring serum IL-1β, TNF-α, and BMP-2). RESULTS: All experimental rabbits achieved cartilage transection (mean, 11.83 ± 0.41 days). No significant inflammation or fibrosis was observed. TEM revealed severe chondrocyte damage and disorganized collagen fibers in the experimental group, whereas the sham group showed near-normal ultrastructure. MMP-1 protein and mRNA were significantly elevated in the experimental group versus the sham group (P < 0.05), whereas TIMP-1 showed no differences. TNF-α was higher in the experimental group on day 11 (vs. control, P < 0.001; vs. sham, P < 0.01) and remained elevated versus controls at 2 weeks (P < 0.01). IL-1β showed no intergroup differences. BMP-2 was significantly higher in the experimental group than in both the control and sham groups at 4 and 8 weeks (P < 0.001 and P < 0.01, respectively), but showed no difference versus the sham group at other timepoints. CONCLUSION: Sustained magnetic compression effectively transects rabbit xiphoid cartilage, providing key proof-of-concept evidence for cartilage transectability and establishing a foundational biomechanical rationale for future in vivo animal models mimicking TBR-type CES. CLINICAL TRIAL NUMBER: not applicable.