Cryopreserved, irradiated tracheal homograft transplantation for laryngotracheal reconstruction in human beings☆

Abstract

Subglottic tracheal stenosis is a common clinical entity. Management in severe cases is often problematic. Various techniques for tracheal replacement have been used with varying degrees of success. In this study we used cryopreserved, irradiated tracheal homografts, the use of which in human beings has not been reported previously. In a sterile setup, the tracheas were harvested from donor cadavers within 24 hours of death. The grafts were initially kept at 57 degrees C for 20 minutes; they were then placed in a -70 degrees C chamber for another 2 to 3 days or more and were irradiated to 25 kGy (2.5 million rad). Finally, the grafts were stored at -70 degrees C until usage. Seven patients underwent the surgery, but only 4 are presented here. In the remaining 3 patients, the follow-up time was too short to be evaluated. Four patients, 2 male and 2 female (aged 2-40 years, mean 16 years), with severe subglottic tracheal stenosis underwent segmental tracheal graft reconstruction. Immunosuppressant medications were not given to any patient. Follow-up ranged from 18 to 20 months. Three patients successfully underwent decannulation, and 1 patient had local infection and dislodgment of the intraluminal stent with subsequent restenosis. The postoperative tracheal lumen appeared to be near normal, with histologic evidence of normal respiratory epithelium at the grafted site. In conclusion, cryopreserved, irradiated tracheal homograft transplantation is a valuable alternative for subglottic tracheal reconstruction.

Tracheal cryopreservation: caspase-3 immunoreactivity in tracheal epithelium and in mixed glands

“…Most investigators agree that cryopreservation has an immunomodulating effect on tracheal allografts since it decreases antigenicity (5)(6)(7)(12)(13)(14)(25)(26)(27)(28). This is attributed to the depletion of class II leukocyte antigen expression due to the exfoliation of tracheal epithelium produced during the freezing and defrosting process (3,5,6,11,28,29).…”

Experimental regeneration of canine larynx: a trial with tissue engineering techniques

“…Factors contributing to unsatisfactory outcomes include: (i) difficulty in reconstructing delicate tissues and structures (having other functions), which are anatomically located in the practically inaccessible larynx, which as a whole is influenced by movements of swallowing and vibrations of vocal cords; (ii) the organ per se is located at an impractically accessible anatomical site; and (iii) factor (i) imposes high-risk operative procedures. Although autologous tissues [4 Á11] and homografts [12,13] have hitherto been employed as implant materials for laryngeal reconstruction, damage inflicted on the donor site and/or the risk of donorÁrecipient disease transmissions warrants a more useful and a clinically more efficient approach. Moreover, in cases with tumors in the larynx, deformities of the reconstructed site render it difficult to monitor tumor recurrence.…”

Engineering a Composite Neotrachea in a Rat Model

“…10,11 However, such an allograft becomes nonviable tissue, i.e., a graft without a blood supply. A nonvascularized allograft is highly subject to infection and rejection when exposed.…”

“…12,13 Fixed cadaveric tracheal allografts have been used clinically to repair short, partial (noncircumferential) tracheal defects due to benign stenosis with variable success. 11,14 Circumferential and longer defects are much more difficult to reconstruct, and a much higher failure rate is likely with allograft reconstruction.…”