Establishing an esophago-pleural fistula disease model in rabbits with a magnetic compression technique

Esophageal pleural fistula (EPF) primarily arises as a complication of esophageal surgery, malignant tumors, or trauma. The high mortality rate associated with EPF underscores the critical need for early diagnosis and aggressive treatment, which often involves a multidisciplinary approach including thoracic drainage, broad-spectrum antibiotics, nutritional support, and often surgical or endoscopic intervention. Despite its clinical severity, a corresponding animal disease model for mechanistic and therapeutic research remains unavailable.

To establish a stable and reproducible EPF animal model using magnetic compression technology (MCT).

EPF modeling surgery was successfully performed on 20 New Zealand white rabbits (weight: 2-3 kg) with our self-developed MCT device. Postoperatively, radiographic confirmation of magnet positioning was conducted within 24 hours. Fistula tract tissue samples were subjected to hematoxylin-eosin and Masson's trichrome histochemical staining. Pathological specimens were intentionally withheld from a subset of rabbits (n = 8) to assess long-term stability; these animals were monitored for a prolonged period until postoperative day (POD) 30 before euthanasia, allowing for observation of chronic changes.

The rabbit model of EPF was successfully established. The average surgical time was 26.6 ± 4 minutes. Magnets were spontaneously excreted at 7.0 ± 0.7 days postoperatively (n = 18/20). Pleural abscesses developed in 14 rabbits (70%). All rabbits (n = 8) reached the 30-day endpoint without intervention. Data analysis revealed no significant correlation between the abscess size, surgery time, anesthesia time, magnet discharge time, and weight changes within POD 9. Gross pathology confirmed the formation of EPFs and pleural abscesses. Spontaneous healing tendencies were observed in a subset of fistulas (n = 6). Histological analysis revealed esophageal epithelial migration advancing toward the fistula lumen, whereas pleural abscess cavities contained extensive necrotic debris characterized by neutrophilic infiltration and fibrin deposition, collectively validating the model's success.

The magnetic compression-derived rabbit EPF model exhibits high establishment success and prolonged viability, enabling robust pathophysiological research.