Abstract 10441: Development of in vivo Tissue-Engineered Vascular Grafts With an Ultra Small Diameter of 0.6 mm (MicroBiotubes)
Introduction and Hypothesis: Small-caliber arterial substitutes are needed for various revascularization procedures. Biotubes, in vivo tissue-engineered autologous tubular tissues, have high performance potential as a reliable aortic vascular graft with diameter of over several mm. This study challenged the development of micron-ordered caliber Biotubes (MicroBiotubes: MBs) with diameter of 0.6 mm and their quality and patency were non-invasively observed by optical coherence tomography (OCT) and magnetic resonance angiography (MRA), respectively.
Methods: The mold for multiple preparing of MBs was assembled by several stainless wires covered with silicone tubes with outer diameter of 0.6 mm (Fig. 1A). The molds were surgically embedded into the dorsal subcutaneous pouches of rats. After 2 months, the molds were harvested with surrounding tissues and MBs were obtained, as encapsulated connective tissues, by removing the molds. MBs (length, 10 mm) after storing in 70% ethanol were allogenicaly implanted in rat femoral arteries (diameter, ca. 0.5 mm) by end-to-end anastomosis without use of any anticoagulant agents (Fig. 1B).
Results: The OCT imaging showed homogeneous wall thickness without damage of MBs with a diameter of 0.6 mm. Patency at immediately after implantation was confirmed also by the imaging and at 1 month was by MRA (83.3%, n=6). Vascular structure with multi-layered elastic fiber and collagen fiber was constructed with endothelial cells and α-SMA-positive cells. The high patency was maintained for 6 months (Fig. 1C).
Conclusions: The world’s smallest caliber vascular grafts with high patency and in situ regenerative activity were developed. The Biotubes could acquire high reliability for vascular grafts with diameter ranging from micrometer to centimeter.
Author Disclosures: D. Ishii: None. J. Enmi: None. H. Iida: None. T. Satow: None. J.C. Takahashi: None. K. Kurisu: None. Y. Nakayama: None.
- © 2015 by American Heart Association, Inc.