Fabrication of a neotrachea using engineered cartilage.
OBJECTIVE
Surgical management of long-segment tracheal stenosis is an ongoing problem. Many types of tracheal prostheses have been tried but with limited success because of immune rejection, graft ischemia, or restenosis. Tissue engineered cartilage may offer a solution to this problem, although scaffolds, which are currently often used for support, can lead to biocompatibility problems. This study investigated the feasibility of scaffold-free cartilage to tissue engineer a vascularized neotrachea in rabbits.


METHODS
Animal study.


METHODS
Autologous neotracheal constructs were implanted in the abdomen of six New Zealand white rabbits. Auricular chondrocytes were used to engineer scaffold-free cartilage sheets. A muscle flap raised from the external abdominal oblique muscle and the engineered cartilage were wrapped around a silicone stent to fabricate a vascularized neotrachea in vivo. In two of the six rabbits, a full thickness skin graft was used to create an epithelial lining. The constructs were harvested after either 6 or 10 weeks.


RESULTS
All neotracheal constructs were healthy with well-vascularized and integrated layers. The implanted engineered cartilage underwent a remodeling process, forming a solid tracheal framework. Constructs harvested after 10 weeks proved to have significantly better mechanical properties than after 6 weeks and were comparable with the rabbit's native trachea.


CONCLUSIONS
Scaffold-free engineered cartilage can successfully fabricate a well-vascularized, autologous neotrachea with excellent mechanical properties. The results suggest that this approach can be used to reconstruct tracheal defects in rabbits.
Weidenbecher
Mark
M
Department of Orthopaedics/Otolaryngology-Head and Neck Surgery, Case Western Reserve University, Cleveland, Ohio 44106, USA. m.weidenbecher@gmail.com
Tucker
Harvey M
HM
Awadallah
Amad
A
Dennis
James E
JE
D000009:Abdominal Muscles / Q000637:transplantation; D000818:Animals; D001696:Biomechanical Phenomena; D002356:Cartilage / Q000166:cytology / Q000637:transplantation*; D018929:Cell Culture Techniques; D019902:Chondrocytes / Q000166:cytology; D004425:Ear Cartilage / Q000166:cytology; D004548:Elasticity; D004848:Epithelium / Q000502:physiology; D005240:Feasibility Studies; D008297:Male; D018583:Pliability; D011817:Rabbits; D012828:Silicones; D016038:Skin Transplantation / Q000473:pathology; D015607:Stents; D013314:Stress, Mechanical; D013524:Surgical Flaps; D013997:Time Factors; D046509:Tissue Culture Techniques; D023822:Tissue Engineering / Q000379:methods*; D014132:Trachea / Q000033:anatomy & histology / Q000601:surgery*
D012828:Silicones