End-stage renal disease (ESRD) is a complication associated with diseases such as diabetes, hypertension, and other glomerulonephropathies associated with aging.1 Annually, more than 350,000 persons require hemodialysis for ESRD in the United States. Within the next decade, this incidence is expected to nearly double.2
The financial implications associated with the management of vascular access for these patients is staggering; costs already exceed $1 billion annually and are expected to rise more than 6% per year.2
Vascular access options for hemodialysis include the placement of arteriovenous (AV) fistulas, AV grafts, and double-lumen, cuffed central vein catheters.3 Vascular access complications constitute one of the most common chief complaints of ESRD patients who present to the emergency department.4 The emergency physician must be comfortable managing hemodialysis access problems in order to maintain the long-term functionality of these dialysis access sites and prevent morbidity.5
Clotted Arteriovenous Graft/Fistula
An arteriovenous fistula is a surgical anastomosis of an artery with a vein, bypassing the capillary bed, to allow the faster flow rates needed for hemodialysis. Similarly, an arteriovenous graft serves the same function but utilizes a synthetic tube, not the patient’s naive blood vessels, to bridge arterial and venous flow while avoiding tiny capillaries.
Thrombosis represents a common complication contributing to frequent hospitalizations of dialysis-dependent patients.6 Between 85% and 90% of AV access thromboses are associated with venous outflow stenotic lesions caused by endothelial and fibromuscular hyperplasia. Physiologically, venous stenosis increases resistance to blood flow, which in turn results in increased venous pressure, decreased blood flow, and ultimately, thrombosis.7
Successful diagnosis of a malfunctioning AV graft or fistula mandates a proper evaluation of the dialysis access site. Upon examination, there will be loss of a thrill (a slightly prolonged, vibratory pulsation) or bruit (a “whooshing” sound heard on auscultation) over the access site that indicates stenosis or thrombosis.8 Once identified, immediate vascular surgical consultation is warranted in the emergency department.
Surgical thrombectomy has been the standard approach to thrombosed AV grafts/fistulas in the past.9 More recently, percutaneous procedures involving thrombolysis with streptokinase or tissue plasminogen activator (tPA) with or without angioplasty have been utilized with variable reported success rates. However, without appropriate specialty consultation, the emergency physician should avoid manipulation of either fistulas or grafts in an attempt to resolve the thrombosis.10