Cutting Balloon Angioplasty in Arteriovenous Fistulas

CREATED in 1966, the Brescia-Cimino arteriovenous fistula remains the most durable form of long-term hemodialysis access (1). Compared with prosthetic grafts, fistulas generally have fewer complications and better overall patency, and are the preferred form of access by the Dialysis Outcomes Quality Initiative criteria (2). Nonetheless, they remain susceptible to the same problems that plague synthetic grafts. Venous stenoses diminish flow in the conduit, leading to poor dialysis, and may ultimately result in thrombosis. Percutaneous thrombolysis of a thrombosed fistula is technically more difficult than percutaneous treatment of a synthetic graft, and some centers will abandon the access rather than attempt fistula pharmacomechanical or mechanical thrombolysis. In contrast, prophylactic angioplasty of a failing access is usually straightforward and typically less demanding on the patient and physician compared with thrombolysis. Prophylactic angioplasty used in this manner has been shown to prolong the life of the access site and is endorsed by the Dialysis Outcomes Quality Initiative (3–5). Therefore, identification of venous stenoses through screening programs is vital to preserve the access and prolong the life of the patient receiving dialysis treatment. One of the shortcomings of percutaneous angioplasty of dialysis-related venous stenoses is a high restenosis rate. Therefore, repeated angioplasty is inevitable in most patients. Primary and restenotic lesions are composed of hyperplastic neointimal tissues predominantly composed of smooth muscle cell proliferation. Restenotic lesions have cell proliferation activity that is much higher than primary lesions and much higher than other diseased human vascular tissues (6). The reason for this discrepancy is not fully understood. Proposed hypotheses include cells in the preexisting neointimal tissue acquiring greater proliferation potential and therefore responding actively to angioplasty (6), the eddy flow hemodynamic pattern of arteriovenous fistulas potentiating proliferation (7), and the severity of vessel wall injury in high-pressure dilation inducing a highly proliferative response (8). Irrespective of mechanism, the important ramification of rapidly developing neointimal hyperplasia is that this process shortens patency in angioplasty. Emerging strategies to blunt this progression include adjunctive radiation therapy, antiproliferative drug therapy, and cutting balloon angioplasty (9–11). In the past 20 years, technologic advances have led to the introduction of new devices to perform and complement angioplasty, including metallic stents, stent-grafts, and high-pressure angioplasty balloon catheters. The latest device to be released in the United States is the Peripheral Cutting Balloon (Boston Scientific, Natick, MA). Variations of the device have been used for more than a decade in Japan and Europe, and its use in dialysisrelated stenoses was first reported in 1995 (12). The device consists of four 0.005-inch atherotomes mounted to a noncompliant angioplasty balloon. The blades are intended to score a lesion during balloon inflation, allowing the balloon to dilate the stenosis. The device is marketed in diameters from 5 mm to 8 mm and lengths of 1 cm or 2 cm. It is inserted via a 7-F sheath over a 0.018-inch guide wire. Maximal recommended inflation pressure is 10 atm. Potential benefits of cutting balloon angioplasty include disrupting the elastic and fibrotic continuity of the vessel wall that causes elastic recoil, inducing controlled injury rather than irregular tears, and enabling lesions to be dilated at lower inflation pressures, thereby reducing barotrauma. In the current issue of JVIR, SingerJordan and Papura (11) describe the use of cutting balloons rather than angioplasty balloons for routine prophylactic angioplasty of failing hemodialysis fistulas. With use of Kaplan-Meier analysis, they report a 6-month primary patency of 76% after cutting balloon angioplasty, with no significant complications. This compares favorably with recent published results of conventional angioplasty that have reported primary patency rates ranging from 50% to 79% (13–16). The results are even more impressive when considering the fact that most of the patients in their series had upper-arm fistulas (83%) rather than forearm fistulas, and a significant minority (42%) had been subjected to previous interFrom the Section of Interventional Radiology, Department of Radiology, University of Chicago Hospitals, Department of Radiology, 5841 South Maryland Avenue, MC 2026, Chicago, Illinois 60637. Received September 16, 2004; revision requested September 20; revision received and accepted September 21. Address correspondence to B.F.; E-mail: bfunaki@midway.uchicago.edu