Graft-to-vein fistulas associated with polytetrafluoroethylene dialysis grafts: diagnosis and clinical significance.

PURPOSE To describe the diagnosis and morphology of abnormal fistulas between dialysis grafts and adjacent native veins in five patients and to discuss their clinical significance. PATIENTS AND METHODS Five patients with PTFE loop-type forearm dialysis grafts were found to have graft-to-vein fistulas in the presence of venous outflow stenosis or occlusion. Three patients underwent surgical revision and two patients underwent percutaneous angioplasty of the venous obstruction. Only one patient required ligation of the abnormal graft-to-vein fistula. The clinical history, dialysis records, surgical reports, and subsequent radiographs of the fistula were reviewed to determine the clinical significance of these fistulas. RESULTS Two patients presented with partial graft thrombosis; the proximal portion of the graft remained patent due to persistent flow through the fistulous communication to an adjacent native vein. Two other patients had a graft-to-vein fistula arising from a pseudoaneurysm, which itself was originating from the graft. After either surgical or percutaneous treatment of the venous obstruction, all five grafts remained functional during the follow-up period. CONCLUSION These iatrogenic, small-caliber fistulas are not uncommon but only manifest during periods of elevated graft pressure. Once the graft pressure is normalized, these fistulas have minimal hemodynamic effect and need not be specifically treated.