Effect of postoperative fractionated radiotherapy on canine ePTFE graft neointima and anastomotic stoma healing: A preliminary experimental study

Abstract

The present study aimed to determine whether postoperative fractionated radiotherapy, at a total dose of 35Gy, affected expanded polytetrafluoroethylene (ePTFE) graft anastomotic stoma healing and neointima formation. The subrenal abdominal aortas of 20 mongrel dogs were replaced with an ePTFE graft. The dogs were randomly divided into either a radiotherapy or nonradiotherapy control group. Grafts were harvested at 4 or 8 weeks after surgery. Hematoxylin-eosin staining, and immunohistochemistry tests for proliferating cell nuclear antigen (PCNA) and CD34 were undertaken to analyze the anastomotic healing and neointima formation. The patency rate of grafts was 100% in each group. No disunion, rupture, or aneurysm was observed in the anastomotic stoma. Eight weeks after surgery, the graft neointima and anastomotic vessel wall of the radiotherapy group were significantly thinner than those of the control group (p<0.05). Immunohistochemical examination was carried out in accordance with histomorphology. Postoperative fractionated radiotherapy after an ePTFE graft replacement of the abdominal aorta did not affect the healing of the anastomotic stoma. However, it suppressed the development of hyperplasia in the anastomotic stoma neointima and graft neointima formation in the short term.