KISHI Kazushi Wakayama Medical College, Associate Professor, 医学部, 講師 (70254547)
木村 誠志 和歌山県立医科大学, 医学部, 助手 (60254546)
山林 尚 和歌山県立医科大学, 医学部, 助手 (10186760)
SATO Morio Wakayama Medical College, Professor, 医学部, 教授 (50154109)
TERADA Masaki Wakayama Medical College, Associate Professor, 医学部, 講師 (80188680)
藤本 尚 和歌山県立医科大学, 医学部, 助手
藤本 尚士 和歌山県立医科大学, 医学部, 講師
FUJIMOTO Hisashi Wakayama Medical College, Associate Professor
|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1997 : ¥200,000 (Direct Cost : ¥200,000)
Fiscal Year 1996 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1995 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Purpose : To elucidate and compare histocompatibility of the tracheal stents by animal experiments.
Materials and Methods. Twelve beagle dogs underwent tracheal stent implantation. Bare Z-stents (BZ), Dacron covered z-stents (DCZ), Polyurethane coated Dacron covered Z-stents (PUZ), Polyethylene mesh stents (PEM), and Nitinol knitted stents (NKT). The stents were deployed in the trachea or main stem bronchus under general anesthesia and endoscopic guidance. Radiogram was taken immediately after and monthly endoscopic examination was performed. Dying animals immediately, and half of the alive at the seventh month, were sacrificed for histologic examination.
Results. For the first two months there were no abnormality in bronchoscopic findings. However at the third month a conspicious granulation, hyperplasia of mucosa and ulnceration ocurred in Bare Z-stent group. The stents were firmly involved in the tissue ingrowth. Similar but lighter findings were observed in the bare portion of DCZ and PUZ groups. Such granulamatous ingrowth was hardly found in the PEM and covered portion of the DCZ and PUZ.A bulge of glanuroma was found at the distal end of PEM.Most of NTK was patent. There was dying or dead animals in BZ, PUZ, at the third month due to or related to the tracheal stenosis, and at the fifth month The other BZ, DCZ, PEM.At the seventh month the alives were o/2 of BZ, o/2 of DCZ, 1/2 of PUZ, 3/4 of PEM, and 2/2 of NTK.All stented region showed narrowing by granulation tissue ingrowth.
Conclusion : From results of this beagle experiment all type of endotracheal stents were patent for the first two months and have glanuration tissue or (sub)mucosal hyperplasia, within seven months. In the decreasing order of frequency of granulation, NTK, PEM, PUZ, DCZ, and BZ.The granulation reaction speculatively came from mechanical irritation and stents shoud have more sophisticated structure, otherwize, effective and safe countermeasure should be devised to these reactions.