Experimental study on vascular graft. II. Replacement of inferior vena cava and abdoninal aorta with the autogenous segment of small intestine submucosa

Replacement of abdominal vena cava with a fresh autogenous substitute, the segment of small intestinal submucosa, was attempted in 15 animals. Five segments were prepared from the intestine smeared with iodine tincture, and reinforced with a steel coil externally in the entire length and a steel or polyethylene ring at the anastomosis. Thoracoabdominal long implantation was done in three animals, of which one with the intestinal segment devoid of mucosa, and the other two with the submucosa. Replacement of abdominal vena cava with the submucosa taken out of the intestinal segment preserved for nine days in 1% mercurochrome solution, or 0.1 % acrinolum solution was done in one animal each. In these two a coil and two rings were also applied. Replacement of abdominal aorta with the double layer tube of a reconstructed submucosa and another very porous Tetoron gauze was done in two animals, each coupled with the abdominal vena cava replacement at the same time. Of these experiments, aorta replacements were nearly patent in both. The abdominal vena cava replacements made of the submucosa treated with iodine tincture were patent in three. The one that was preserved in acrinolum showed moderate constriction. Most of the others were also observed for a long period of time but these all occluded in spite of the initial patency which was revealed at three to seven days in cavograms, and the time of the occlusion was not determined. The internal surface of the segment of submucosa, being implanted, is covered in the first stage with the deposition of fibrin, which is subsequently organized into a fibrous layer, in the same manner as that of the synthetic graft. Another disadvantage of this substitute is its readily collapsible tendency. Infection is preventable in the experiment. The substitute seems to be useful for the replacement of aorta and for the short segment of vena cave.