Tissue-engineered patch for the reconstruction of inferior vena cava during living-donor liver transplantation

In living-donor liver transplantation, only a portion of the donor's liver is grafted into the recipient; therefore, if the hepatic vein and inferior vena cava (IVC) in the recipient fail to be transformed or dilated properly, it could cause inadequate blood flow from the liver graft to the IVC. We have developed an easy-to-use tissue engineered patch that can be used for the reconstruction of the hepatic vein and IVC. Five hybrid pigs (weighing 15-30 kg) served as the recipients of the patch. A bioabsorbable polymer sheet was used to produce the patch, with no cells seeded. The pigs were laparotomized, followed by the removal of a 3 x 2-cm portion of the infrahepatic IVC, which was then patched with the polymer sheet. Three months after the operation, the graft site was removed and subjected to gross and histologic examinations. All five pigs survived until they were killed 3 months after the operation. On gross examination, the polymer sheet grafted onto the IVC was completely absorbed, and the graft site was morphologically similar to the native IVC. In all five pigs, the patched IVC was free of stenosis or deformation. Immunohistochemical examination revealed that the patch site was lined with endothelial cells and that smooth muscle was present under the epithelium. Like the native IVC, the patch site tested positive for factor VIII. These findings suggest that this polymer sheet may be useful for the reconstruction of the IVC and hepatic vein during living-donor liver transplantation in humans.