PurposeTo assess long-term patency rates of cephalic arch stent grafts in brachiocephalic fistulae and the importance of device position. Materials and MethodsThis retrospective study reviewed 152 patients with dysfunctional brachiocephalic fistulae and cephalic arch stenosis treated with stent grafts (Viabahn; W. L. Gore) at a single tertiary center between 2012 and 2021. The median age was 67.5 years (range, 25–91 years), and the median follow-up period was 637 days (range, 3–3,368 days). A grading system of protrusion was applied: (a) Grade 0, no protrusion; (b) Grade 1, perpendicular; and (c) Grade 2, in-line protrusion. Subsequent fistulograms were available in 133 (88%) of the 152 patients and were assessed for central vein stenosis within 10 mm of the stent graft. Clinical records were assessed for sequelae of stent graft protrusion. Stent graft primary and cumulative circuit patencies were calculated using the Kaplan-Meier method. ResultsProtrusion was documented in 106 (70%) stent grafts—56 Grade 1 and 50 Grade 2. Central vein stenosis was seen in 1 (2%) case of no protrusion (Grade 0) and 38 (40%) cases of protrusion (P < .0001). There was no significant difference in stenosis between Grade 1 and 2 protrusion (P = .15). No adverse clinical sequelae occurred in 147 (97%) patients. Eight patients had a new access subsequently formed in the same arm, and 3 of these 8 patients developed symptoms due to the previous stent graft protrusion (all Grade 2). The primary patency rates of the stent-grafts at 6 and 12 months were 73% and 50%, respectively. The cumulative access circuit patency rates at 1, 2, and 5 years were 84%, 72%, and 54%, respectively. ConclusionsThis study demonstrated that protrusion of a cephalic arch stent graft into the central vein is safe and only clinically relevant when a subsequent ipsilateral access is created.