Effect of Anastomotic Method on Intimal Hyperplasia in Rabbit Aorta

PURPOSE: The clinical advantages of end-to-end (ETE) anastomosis have not been clear despite its biomechanical advantage over end-to-side (ETS) anastomosis. We compared the histomorphometric features of intimal remodeling after ETE and ETS anastomosis in a rabbit aortic bypass model. METHODS: Thirty-two bypass operations, 16 with ETS and 16 with ETE anastomoses, were performed using aortic allografts of donor rabbits (15 per group) and polytetrafluoroethylene (PTFE) grafts (1 per group). To minimize bias from the immunologic response to aortic allografts or graft size, a long aortic tissue obtained from one donor was divided into 2 pieces and shared between each ETE and ETS bypass. PTFE graft bypasses, which are commonly used in clinical practice, were performed to provide comparison results for an allograft with a different compliance. Vessels were harvested at 1 day (1 per group), 5 days (1 per group), and 4 weeks (14 per group, including the PTFE bypass group) after surgery. Intimal thickening was evaluated with hematoxylin-eosin, van Gieson, immunohistochemical staining and Western blot analysis of TNF-alpha and proliferative cell nuclear antigen (PCNA) expression. RESULTS: Mean intimal thickness and volume (0.721+/-0.047 mm, 5.734+/-0.387 mm3 vs. 0.883+/-0.048 mm, 9.068+/-0.462 mm3) and intima/media volume ratio (0.70+/-0.05 vs 1.08+/-0.06) were significantly smaller in ETE (P<0.05). Western blotting showed a marked increase in TNF-alpha (203.15+/-5.29 vs. 494.49+/-6.11) and PCNA concentrations (152.66+/-7.37 vs. 175.53+/-4.36) in the ETS group. CONCLUSION: ETE anastomosis results showed significantly decreased inflammatory reaction and volume of intimal hyperplasia, and therefore seemed to be associated with better long-term graft patency.

Feasibility Assessment of Interposition Vessel Graft Substitutes in Dog Models for Later Clinical Application to Middle Hepatic Vein Reconstruction during Living Donor Liver Transplantation

PURPOSE: Most of grafts used as interposition conduits for middle hepatic vein (MHV) in living donor liver transplantation (LDLT) have been allografts and autografts. Recently, polytetrafluoroethylene (PTFE) and bovine pericardium patch have also been used. Thus, we performed large-animal lab tests to assess the feasibility of interposition vessel graft substitutes for MHV. METHODS: The inferior vena cava was replaced in 9 dogs with allograft (3), PTFE (3), and bovine pericardium patch (3). After 28 days, patency rate, outer and inner diameter, intimal thickness, histology, and immunohistochemistry were evaluated according to interposition grafts. RESULTS: The allograft and PTFE groups were all patent at post-operative week 4, but the bovine group was not patent in all dogs. Outer diameter of anastomotic site at 4 weeks was 8.41+/-0.37, 10.83+/-0.51, and 7.41+/-0.86 mm in allograft, PTFE, and bovine group, respectively. Inner diameter of interposition graft at 4 weeks was 7.90+/-0.23, 6.33+/-0.68, and 0 mm in allograft, PTFE, and bovine groups, respectively. Intimal thickness was 48.0+/-8.6, 113.8+/-45.3, and 218.3+/-59.9microm in allograft, PTFE, and bovine groups, respectively. In histologic findings, inflammation was most severe in the bovine group. Intima of anastomotic site in the bovine group was thickest in all groups. Proliferation of smooth muscle cells was most severe in anti-alpha-actin antibody test in bovine group. CONCLUSION: Our data implicate that the use of allografts and PTFE grafts is more feasible than bovine pericardium for MHV reconstruction in LDLT.

The Effect of Intra-portal Infusion of Glucose-insulin-potassium (GIK) Solution on the Energy Metabolism during Cold Preservation in a Small-animal Model for Liver Transplantation / 대한이식학회지

PURPOSE: The effect of intra-portal infusion of glucose-insulin-potassium (GIK) solution on the energy metabolism during cold preservation was investigated using a small-animal liver transplantation model. METHODS: Fifteen white rats were divided into 3 groups: the group A (feeding group) were fed normally before experiment. The group B (fasting group) and group C (GIK group) were fasted from 3 days before experiment, by which acute nutritional deficiency state was induced. In group A and B, the whole liver was procured after intra-portal perfusion of HTK solution and serial liver biopsies were performed during the cold preservation period with 4degrees C HTK solution. In group C, intra-portal GIK solution infusion for 1 hour preceded liver graft harvest. From the liver tissues, the relative intracellular glycogen contents and the ATP concentration were measured. RESULTS: Relative glycogen contents in group A were 100% at 0 h, 64.6% at 2 h, 54.9% at 4 h, and 16.2% at 8 h; 10.3%, 8.3%, 4.9% and 0%, respectively in group B; 109.2%, 96.9%, 54.2% and 9.7%, respectively in group C. There was a temporary supercharge of ATP level in group C only at 0 h. Apoptosis was less expressed in group C comparing with group A and B. CONCLUSION: Rapid intra- portal infusion of GIK solution could make intrahepatic glycogen content fully restored to the normal level. Considering that intracellular glycogen is the main energy source during immediate post-transplant period, its restoration may contribute to improvement of post-transplant graft function.