THE ORIGINS OF INTERVENTIONAL NEPHROLOGY
The early history of dialysis was marked by advances in vascular access, conceived and developed by visionary nephrologists, including the Scribner shunt and the Brescia-Cimino arteriovenous fistula (AVF). Without a means of obtaining reliable, repeated blood access, the delivery of chronic hemodialysis would not have been possible. Few nephrologists have maintained a primary role in vascular access creation and maintenance, particularly in Europe; Konner reported a series of 748 consecutive native arteriovenous fistulae constructed by a nephrologist, with 2-year secondary patency in diabetics and nondiabetics ranging from 75% to 96%, respectively. During the 1970s and 1980s in the United States, nephrologists’ interest and involvement in vascular access waned. This may have been due to progress in what were perceived as more scientifically rewarding areas of study, as opposed to the relatively mundane “plumbing” problems of vascular access. Certainly, neither technical proficiency nor a rigorous scientific approach to vascular access was emphasized at most nephrology training centers in the United States. A survey of nephrology training programs in 2008 indicated that only about 20% incorporated procedural training in vascular access.
At the same time, particularly in the United States, there was increased utilization of synthetic polytetrafluoroethylene (PTFE) grafts in favor of native arteriovenous fistulae. This shift may have been driven by device marketing, surgical reimbursement practices, limited long-term venous access catheters available for use as “bridges” to native fistulae, and increasing emphasis on short, high-efficiency hemodialysis treatments. The result was a U.S. hemodialysis patient population with a high prevalence of PTFE grafts, low utilization of arteriovenous fistulae, and not-incidentally, the highest dialysis patient mortality of all industrialized nations. In 1999, 49% of United States’ hemodialysis patients were dialyzing with AV grafts, 28% with native fistulae, and 23% with venous catheters.
During this period of a rapidly growing hemodialysis patient population, increasing PTFE graft utilization, and decreased involvement of nephrologists in the management vascular access, there was a predictable crisis in the access-related medical care of these patients. Management of access dysfunction and thrombosis was largely “reactive” and primarily utilized open surgical techniques. The role of venous stenosis contributing to arteriovenous graft thrombosis and failure was underappreciated. In the late 1980s, interventional radiologists began to recognize these problems, and became involved in the management of hemodialysis access dysfunction. In 1991, Valji et al. reported a method for declotting of arteriovenous hemodialysis grafts using pharmacomechanical thrombolysis and angioplasty. Numerous other reports and variations on this method followed, with increasing acceptance of percutaneous interventions in the management of hemodialysis access dysfunction. Largely, however, nephrologists remained on the periphery, as vascular access remained the province of the vascular surgeons, and increasingly, the interventional radiologists.
The vital role of vascular access in the comprehensive care of hemodialysis patients cannot be overemphasized. Care of the hemodialysis patient includes management of uremia, hypertension, sodium and water balance, anemia, mineral metabolism, metabolic ...