EVALUATION OF ANASTOMOTIC HYPERPLASIA PROGRESSION USING THE CYCLIN SPECIFIC ANTIBODY MIB-1

BACKGROUND: Delayed failure of prosthetic arterial grafts is primarily due to the development of anastomotic intimal hyperplasia, This repor t follows the proliferation of smooth muscle cells that ensues after p rosthetic arterial grafting, using the cyclin-specific antibody MIB-1. METHODS: Six-mm expandable polytetrafluoroethylene (ePTFE) grafts wer e placed end-to-end in the carotid arteries of mongrel dogs, Animals w ere randomly assigned to sacrifice intervals of 2, 7, 14, and 30 days, Serial coronal sections were cut and immunohistocytochemistry perform ed using the MIB-1 antibody. RESULTS: The control carotid artery had n o definable proliferation. Two days after grafting, there was brisk pr oliferation in the upper one third of the arterial media, By 7 days, p roliferation and migration of smooth muscle cells was seen above the i nternal elastic lamina, in which 50% of the cells were MIB-1 positive, Fourteen days after graft placement, proliferation continued in the n eointima; however, the proliferation index was diminished compared wit h previous time intervals, At 30 days, despite a dramatic increase in lesional increase, there was a marked decrease in the overall prolifer ation of cells. CONCLUSIONS: Following placement of a prosthetic arter ial graft, there is initial brisk proliferation of cells in the arteri al media, with migration, ongoing proliferation, and resultant develop ment of a localized cellular neointima, Over a 30-day period, the perc entage of cells proliferating subsides in contrast to the progressive increase in the size of the neointima, Immunohistocytochemistry with t he MIB-1 antibody is a useful tool in defining the cellular kinetics a fter prosthetic arterial grafting.