Bioabsorbable device for small-caliber vessel anastomosis

Although the devices for large-caliber vessel (>2-mm diameter) anastomosis are available, there are no devices for performing anastomosis of small-caliber vessels. We designed a hooked device composed of a bioabsorbable polymer for sutureless anastomosis of small-caliber vessels. The efficacy of this device was evaluated by in vitro degradation and arterial-fixation strength tests as well as in vivo transplantation experiments with common carotid arteries of growing SD rats. A nonabsorbable device without hooks served as the control in the fixation strength and animal experiments. The tensile strength of the bioabsorbable device decreased to 27 and 9% of the initial value after 8- and 24-week incubation, respectively. The fixation strength was greater and the anastomotic time was shorter with this device than with the control. The transplantation experiments showed complete endothelial bridging in both devices at 2 weeks after surgery (n = 6). The control device created a considerable protrusion into the arterial lumen at 8 postoperative weeks, whereas the experimental device did not (n = 6). Arterial diameter measurements detected a significant difference between the inner diameters at the respective anastomotic sites (n = 6, P < 0.05) and demonstrated that the control device hindered the vessel growth while the experimental device did not. Therefore, the bioabsorbable hooked device was an effective tool for anastomosis of small-caliber arteries (ca. 1-mm diameter).