Growth and Development of Homograft Tracheal Transplants in the Piglet Model

Abstract

Homograft tracheal transplantation results in a tracheal segment that is replaced with collagen. The transplanted cartilage is resorbed, leaving a significantly malacic segment. Homograft tracheal transplantation might result in a small malacic airway with little potential for growth when performed in children.

The Fate of Homograft Tracheal Transplants in Sheep

“…In our opinion, the stability of the implant is only guaranteed by the remaining scar. Recently a comparable study on the transplantation of chemically preserved trachea in pigs was published [72]. That study arrived at the same results as our own experiments: The chemically preserved tracheal allotransplants are absorbed.…”

“…The result—a stable air passage—is thus quite positive. Nevertheless, the transplants could be absorbed in the manner described by others and ourselves [72].…”

Biomechanical and biochemical characterization of porcine tracheal cartilage

“…The goal of this study was to more completely define the mechanical and biochemical characteristics of native porcine tracheal tissue. We focus on the porcine model because the geometry of large animal preclinical models most closely represents that of the human trachea; the immunological response to airway transplantation is understood; postoperative care protocols are well developed for airway replacement; and tissue‐engineering developments in this species have led to promising early clinical success …”

Microvascular Transfer of Long Tracheal Autograft Segments in the Canine Model

“…The reconstruction of circumferential tracheal defects greater than 6.4 cm or of 50% of the total tracheal length remains a reconstructive dilemma. 1 Attempts at reconstruction with prosthetic materials, 2,3 autogenous grafts, 4–8 and pretreated trachea 9–11 have been largely unsuccessful.…”

“…Nonvascularized grafts, with and without pretreatment, have been extensively explored 16–18 ; however, recent experimental work supports prior clinical observations that nonvascularized tracheal segments tend to undergo cartilage resorption, collagen replacement, and tracheomalacia. 11,19 Zagalo et al demonstrated that nonvascularized four‐ring tracheal autografts acutely sloughed the ciliated epithelium and eventually led to tracheal stenosis. 19 It has become clear that nonvascularized allografts are not sufficient for the reconstruction of extensive tracheal defects.…”