Experimental Replacement of Pig Trachea with Novel Bioprosthesis from Harp Seal

Tracheal replacement has been a challenging problem for thoracic surgeons for over half of a century. We evaluated the in-vivo performance of a new tracheal bioprosthesis derived from Harp seal (Phoca groelandica) trachea that was fixed and preserved in 0.625% buffered glutaraldehyde solution for 3 months. Ten young male pigs weighing 27–32 kg (mean, 28.7 kg) underwent replacement of a tracheal segment with this new bioprosthesis. The length of replaced trachea was 1.8–2.4 cm (mean, 2.17 cm), representing 2–3 cartilage rings. All pigs survived the operation uneventfully. No immunosuppression drugs were used. The pigs eventually developed dyspnea and were euthanized on postoperative day 17–39 (mean, 30.8 days). Macroscopic and histological analysis showed an intact bioprosthesis but near-total occlusion of the native trachea by a ring of inflammatory infiltration at the site of distal anastomosis. More experiments involving a different concentration of the preservation agent, different management, and perhaps the use of bioengineering techniques are needed to improve the performance of this novel bioprosthesis.