title: In vivo evaluation of an in-body, tissue-engineered, completely autologous valved conduit (biovalve type VI) as an aortic valve in a goat model.
abstract: Using simple, safe, and economical in-body tissue engineering, autologous valved conduits (biovalves) with the sinus of Valsalva and without any artificial support materials were developed in animal recipients' bodies. In this study, the feasibility of the biovalve as an aortic valve was evaluated in a goat model. Biovalves were prepared by 2-month embedding of the molds, assembled using two types of specially designed plastic rods, in the dorsal subcutaneous spaces of goats. One rod had three projections, resembling the protrusions of the sinus of Valsalva. Completely autologous connective tissue biovalves (type VI) with three leaflets in the inner side of the conduit with the sinus of Valsalva were obtained after removing the molds from both terminals of the harvested implants with complete encapsulation. The biovalve leaflets had appropriate strength and elastic characteristics similar to those of native aortic valves; thus, a robust conduit was formed. Tight valvular coaptation and a sufficient open orifice area were observed in vitro. Biovalves (n = 3) were implanted in the specially designed apico-aortic bypass for 2 months as a pilot study. Postoperative echocardiography showed smooth movement of the leaflets with little regurgitation under systemic circulation (2.6 ± 1.1 l/min). α-SMA-positive cells appeared significantly with rich angiogenesis in the conduit and expanded toward the leaflet tip. At the sinus portions, marked elastic fibers were formed. The luminal surface was covered with thin pseudointima without thrombus formation. Completely autologous biovalves with robust and elastic characteristics satisfied the higher requirements of the systemic circulation in goats for 2 months with the potential for valvular tissue regeneration.
authors.affiliation: Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan. takewa@ri.ncvc.go.jp
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Takewa
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamanami
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kishimoto
authors.forename: Mamoru
authors.initials: M
authors.lastname: Arakawa
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kanda
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Matsui
authors.forename: Tomonori
authors.initials: T
authors.lastname: Oie
authors.forename: Hatsue
authors.initials: H
authors.lastname: Ishibashi-Ueda
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tajikawa
authors.forename: Kenkichi
authors.initials: K
authors.lastname: Ohba
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yaku
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Taenaka
authors.forename: Eisuke
authors.initials: E
authors.lastname: Tatsumi
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Nakayama
mesh_terms: D000818:Animals; D001021:Aortic Valve; D001705:Bioprosthesis; D005240:Feasibility Studies; D006041:Goats; D006350:Heart Valve Prosthesis; D010865:Pilot Projects; D011474:Prosthesis Design; D012850:Sinus of Valsalva; D023822:Tissue Engineering