Vascularized Prelaminated Thermoplastic Bioabsorbable Scaffold in Tracheal Reconstruction

The aim of this study was to evaluate a novel composite material for tracheal reconstruction in an ovine model. A polymer containing various forms of carbon fibers (roving, woven, and nonwoven fabric) impregnated with polysulfone (PSU) was used to create cylindrical tracheal implants, 3 cm in length and 2.5 cm in diameter. Each implant, reinforced with five rings made of PSU-impregnated carbon-fiber roving, had three external layers made of carbon-fiber woven fabric and the inner layer formed of carbon-fiber nonwoven fabric. The inner surface of five implants was additionally coated with polyurethane (PU), to promote migration of respiratory epithelium. The implants were used to repair tracheal defects (involving four tracheal rings) in 10 sheep (9-12 months of age; 40-50 kg body weight). Macroscopic and microscopic characteristics of the implants and tracheal anastomoses were examined 4 and 24 weeks after implantation. At the end of the follow-up period, outer surfaces of the implants were covered with the tissue which to various degree resembled histological structure of normal tracheal wall. In turn, inner surfaces of the prostheses were covered only with vascularized connective tissue. Inner polyurethane coating did not improve the outcomes of tracheal reconstruction and promoted excessive granulation, which contributed to moderate to severe stenosis at the tracheal anastomoses. The hereby presented preliminary findings constitute a valuable source of data for future research on a tracheal implant being optimally adjusted for medical needs.

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Tracheal Replacement Using an In-Body Tissue-Engineered Collagenous Tube “BIOTUBE” with a Biodegradable Stent in a Beagle Model: A Preliminary Report on a New Technique

European Journal of Pediatric Surgery ◽

10.1055/s-0038-1673709 ◽

2018 ◽

Vol 29 (01) ◽

pp. 090-096 ◽

Cited By ~ 4

Author(s):

Yasuhide Nakayama ◽

Satoshi Umeda ◽

Yuichi Takama ◽

Takeshi Terazawa ◽

Hiroomi Okuyama ◽

...

Keyword(s):

Internal Surface ◽

Body Tissue ◽

Histological Evaluation ◽

Biodegradable Stent ◽

Tracheal Reconstruction ◽

Tracheal Epithelial Cells ◽

Biodegradable Stents ◽

Tracheal Replacement ◽

A New Technique ◽

Novel Scaffold

Introduction Tracheal reconstruction for long-segment stenosis remains challenging. We investigate the usefulness of BIOTUBE, an in-body tissue-engineered collagenous tube with a biodegradable stent, as a novel tracheal scaffold in a beagle model. Materials and Methods We prepared BIOTUBEs by embedding specially designed molds, including biodegradable stents, into subcutaneous pouches in beagles. After 2 months, the molds were filled with ingrown connective tissues and were harvested to obtain the BIOTUBEs. The BIOTUBEs, cut to 10- or 20-mm lengths, were implanted to replace the same-length defects in the cervical trachea of five beagles. Endoscopic and fluoroscopic evaluations were performed every week until the lumen became stable. The trachea, including the BIOTUBE, was harvested and subjected to histological evaluation between 3 and 7 months after implantation. Results One beagle died 28 days after 20-mm BIOTUBE implantation because of insufficient expansion and retention force of the stent. The remaining four beagles were implanted with a BIOTUBE reinforced by a strong stent, and all survived the observation period. Endoscopy revealed narrowing of the BIOTUBEs in all four beagles, due to an inflammatory reaction, but patency was maintained by steroid application at the implantation site and balloon dilatation against the stenosis. After 2 months, the lumen gradually became wider. Histological analyses showed that the internal surface of the BIOTUBEs was completely covered with tracheal epithelial cells. Conclusion This study demonstrated the usefulness of the BIOTUBE with a biodegradable stent as a novel scaffold for tracheal regeneration.

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