A new model of arteriovenous fistula to study hemodialysis access complications.

ABSTRACT

PURPOSE: This report presents a new animal model of arteriovenous fistula (AVF) with attention given to surgical techniques as well as hemodynamic and pathologic measurements. Of note, this model was created with a tunneled central catheter with the purpose of studying therapeutic interventions, including hemodialysis. METHODS: Side-common carotid artery to end-external jugular vein AVFs were created in eight minipigs. A tunneled central catheter was also placed in the internal jugular vein. After 28 days, hemodynamic measurements of AVF flow and stenosis were performed. The minipigs were then euthanized and the AVFs were harvested for pathologic measurements of neointimal hyperplasia and thrombus volumes. In order to account for variable size of the AVFs, percentage luminal stenosis and degree of intima-media thickening were calculated. RESULTS: After 28 days, all eight AVFs remained patent. On average, 19% of arterial blood flow that approached the AVF traveled through the anastomosis. The average luminal stenosis by angiogram was 61.1%. The average neointimal hyperplasia and thrombus volumes were 1.4×10(8) and 3.8×10(8) µm3, respectively. The average luminal stenosis and intima-media thickening were 65.2% and 430.4 µm, respectively. CONCLUSIONS: This AVF model is ideal because of the relative ease of surgery and husbandry, lack of complications, as well as consistent and rapid development of the neointimal lesion which underlies AVF failure.