Surgical Skills Training with Cryopreserved Rat Stomachs.

The objective of this study is to present a high-fidelity bench model of cryopreserved stomachs that can be used while learning surgical skills. Thirty stomachs were harvested from Wistar rats at the end of non-abdominal research studies. The stomachs were washed with cold saline solution and filled with hyaluronic acid solution. The organs were then placed into cryovials and cryopreserved at -30 °C for 60 days. The stomachs were thawed to room temperature on the day of the surgical skills practice and two full-thickness incisions were made. Reporting on their experiences, 22 participants (73.33%) felt that the cryopreserved stomach was identical to in vivo rat stomachs, 24 (80.00%) reported that the stomach was easy to handle, and 27 (90%) reported the tissue was non-friable. Moreover, 29 participants (96.6%) finished the suturing without tears and 100% recommended it as a biomaterial for surgical training. The cryopreserved stomach is a practical, reproducible, low-cost, and high-fidelity bench model that allows surgical fellows to learn how to handle a stomach and improve their surgical abilities before performing surgery on patients or laboratory animals.

In vivo performance of decellularized tracheal grafts in the reconstruction of long length tracheal defects: Experimental study.

BACKGROUND: The repair of long-segment tracheal lesions remains an important challenge. Nowdays no predictable and dependable substitute has been found. Decellularized tracheal scaffolds have shown to be a promising graft for tracheal transplantation, since it is non-immunogenic. OBJECTIVE: Evaluate in vivo decellularized tracheal allografts performance to replace long tracheal segment. METHODS: Forty-five swines underwent surgery as follows: Fifteen trachea donors and 30 receptors of decellularized trachea allografts. The receptors were randomly divided in five groups (n = 6). In groups I and II, donor trachea segment was decellularized by 15 cycles with sodium deoxycholate and deoxyribonuclease, in group II, the allograft was reinforced with external surgical steel wire. Groups, III, IV, and V decellularization was reduced to seven cycles, supplemented with cryopreservation in group IV and with glutaraldehyde in group V. A 10 rings segment was excised from the receptor swine and the decellularized trachea graft was implanted to re-establish trachea continuity. RESULTS: Both decellularization cycles caused decreased stiffness. All trachea receptors underwent euthanasia before the third post-implant week due to severe dyspnea and trachea graft stenosis, necrosis, edema, inflammation, hemorrhage, and granulation tissue formation in anastomotic sites. Histologically all showed total loss of epithelium, separation of collagen fibers, and alterations in staining. CONCLUSIONS: Both decellularization techniques severely damaged the structure of the trachea and the extracellular matrix of the cartilage, resulting in a no functional graft, in spite of the use of surgical wire, cryopreservation or glutaraldehyde treatment. An important drawback was the formation of fibrotic stenosis in both anastomosis.