Comparison of procedure cost for thrombectomy of arteriovenous fistulas and grafts.

Expenditures on dialysis vascular access now exceed $2.5 Billion annually in the US. Studies suggest that significant savings could be achieved by increasing arteriovenous fistula (AVF) prevalence to >65%. It is common but unsubstantiated opinion that AVF have lower maintenance costs than arteriovenous grafts (AVG). This manuscript tests this hypothesis by direct comparison. Equipment utilization time and supply utilization on 110 thrombectomy procedures on AVF and 258 on AVG were compared. Procedures techniques were standardized within one facility and procedures performed by a multiple but limited number of operators. There were no significant differences in demographic variables and comorbid factors between groups. Time to complete AVF thrombectomy was 1.7 times that for AVG. In addition, major supplies used such as wires and balloons were also significantly greater. Interventionists who took longer than average to thrombectomize AVF took longer than average to thrombectomize AVG. The prevalence of arterial inflow lesions was 1.5 greater in thrombosed AVF versus Thrombosed AVG. Procedure costs when analyzed in terms of procedure time, room utilization, staff, and equipment are significantly greater for thrombosed AVF than thrombosed AVG.

Academic interventional nephrology: a model for training, research, and patient care.

Dialysis vascular access dysfunction is currently a huge clinical problem. We believe that comprehensive academic-based dialysis vascular access programs that go all the way from basic and translational science investigation to clinical research to a dedicated curriculum and opportunities in vascular access for nephrologists in training are essential for improving dialysis vascular access care. This paper reviews the fundamental concepts and requirements for us to move toward this vision.

Role of surgical intervention for cephalic arch stenosis in the "fistula first" era.

Cephalic arch stenosis (CAS) is a frequent cause of vascular access dysfunction in patients with brachiocephalic fistulae. While percutaneous balloon angioplasty has been used to treat CAS, the results of this approach have been poor due to multiple factors including resistant nature of the stenosis, development of early restenosis, as well as poor patency and high vein rupture rates. In this analysis, we report the results of an alternative approach to manage this problem. Thirteen patients with frequently recurring CAS were referred for surgical intervention. Angiographic images recorded during the prior percutaneous procedures were made available to the surgeons. The surgical procedure entailed transecting the healthy portion of the cephalic vein distal to the stenotic segment in the arch, transposing and anastomosing it to the upper basilic/axillary vein. Following surgical revision, development of access dysfunction was treated with percutaneous balloon angioplasty. Patency rates for angioplasty before and after the surgical revision were evaluated. Primary patency rates for angioplasty before the surgical revision were 23%, 8% and 0% at 3, 6, and 12 months, respectively. Following surgical revision, all patients needed angioplasty procedure. However, primary patency increased to 92%, 69%, and 39% at 3, 6, and 12 months, respectively (p = 0.0001). Secondary patency before the surgical revision at 3, 6, and 12 months was 100%, 39%, and 8%, respectively, compared with 92% at 3, 6, and 12 months postsurgical revision (p = 0.0003). The results of this study demonstrate that surgical transposition of the cephalic vein in frequently recurring CAS is a viable option and yields better patency rates for future angioplasty procedures.

Increasing the use of arteriovenous fistula in hemodialysis: economic benefits and economic barriers.

The Fistula First Initiative set a goal of 66% arteriovenous (AV) fistula-based access among US hemodialysis patients. This study modeled the impact of achieving the target AV fistula placement rate on Medicare expenditures and on dialysis patient survival and also reviewed economic disincentives for providers that will inhibit achieving this target. The model projects lifetime costs and survival in the US 2003 incident hemodialysis population. Annual treatment costs were estimated from previous analyses of Medicare expenditures by access modality. Patient survival by mode of access was derived from the Dialysis Morbidity and Mortality Study (DMMS). These parameters were applied to a cohort of patients who meet the 66% AV fistula target and an identical cohort with the current vascular access case mix. Comparison of outcomes yields estimates of differential total expenditures and total patient life-years. If prevalence AV fistula-based access in the 2003 incident hemodialysis cohort were 66% rather than the observed 35%, then the Center for Medicare and Medicaid Services would save $840 million in access-attributed expenditures over the expected lifetime of these patients. However, population survival would increase by 35,000 additional life-years, increasing total lifetime expenditures by a net of $1.4 billion. Relative to the current mix of access modality, the shift to 66% AV fistula would be achieved at a net incremental cost of $40,000 per year of life gained. Economic barriers to reaching this goal include financial disincentives to providing adequate predialysis care, performing AV fistula surgical procedures, and monitoring vascular access flow. Achievement of the 66% AV fistula target is cost-effective. Financial incentives in the form of higher reimbursement to encourage wider use of AV fistula placement also could be cost-effective.

Efficiency and outcomes of emergent vascular access procedures performed at a dedicated outpatient vascular access center.

The outpatient vascular access center (VAC) may have an important impact in improving the outcomes of emergent procedures on nonfunctioning hemodialysis access. An emergent procedure is defined as the absence of a functioning access for hemodialysis, including thrombosed graft or fistula, nonfunctioning dialysis catheters, and the need for access to initiate emergent hemodialysis. The aim of this study was to prospectively evaluate the efficiency and outcomes of all consecutive emergent hemodialysis access procedures during a 3-month period at a single high volume VAC. Data collection for each procedure included anatomic outcome, clinical outcome, the amount of time from referral to procedure and to successful dialysis, 2-week-follow-up to screen for postprocedure complications and fluoroscopy time. A total of 157 emergent procedures were performed in 136 patients with the majority of interventions on nonfunctioning grafts and tunneled catheters. The overall clinical success (defined as successful postprocedure completion of at least one dialysis treatment at the prescribed blood flow) was achieved in 149 out of 157 (95%) cases. 90% of subjects completed their procedure within 24 hours of the initial referral to the VAC. The study also demonstrated a rapid turn around time, with successful dialysis being performed within 24 hours of referral in 61% and within 48 hours in 90% of referrals. This is the first study to demonstrate both the efficiency and successful outcomes of an outpatient vascular access center in treating emergent vascular access problems.

A position statement from the American Society of Diagnostic and Interventional Nephrology.

A procedure-related complication is an unanticipated adverse event that requires therapy. In order to analyze frequency and severity of complications in the process of quality assurance, it is useful to have a classification of complications, indicating the type and severity. The Clinical Practice Committee of American Society of Diagnostic and Interventional Nephrology has developed a Classification of Complications relating to Hemodialysis Vascular Access Procedures, based on the system first proposed by Beathard in 2006. In this system, the "type" refers to the procedure being performed or vessel entered, and the "grade" is based on the intensity of medical care needed to address the complication. This publication describes 10 Types and 4 Grades of complications.

Coding issues for the interventionalist: a consensus statement by the ASDIN.

The field of Interventional Nephrology has matured and expanded over the last decade. The American Society of Diagnostic and Interventional Nephrology (ASDIN) has recognized the need for standardization and uniformity in coding of interventional procedures on dialysis access. After extensive study, an ASDIN committee developed a coding manual in 2004 with revisions in 2005 and 2006, which is available to ASDIN members through the ASDIN web site. This article comprises a brief overview of appropriate coding for access related procedures and contrasts the ASDIN recommendations with a recent interventional radiology generated approach.

Managing the complications of long-term tunneled dialysis catheters.

The Kidney Disease Outcomes and Quality Initiative (K/DOQI) guidelines call for a significant increase in the use of natural vein fistulas. Long-term tunneled dialysis catheters (LTTDCs) will have an important role in facilitating the maturation of natural vein fistulas. LTTDCs also functions as the access of last resort in patients who refuse or have exhausted other forms of permanent vascular access. This article, which is based on the authors' experience as interventional nephrologists, discusses factors influencing catheter function. In addition, the article reviews common complications associated with dialysis catheter insertion, including immediate, short-term, and long-term complications. The topics reviewed include stenoses, thrombus formation, fibrin sheath formation, infections, and vascular ingrowth. Suggestions for management are also discussed.

Pharmacomechanical thrombolysis of natural vein fistulas: reduced dose of TPA and long-term follow-up.

Twenty-five episodes of pharmacomechanical thrombolysis of 20 clotted arteriovenous fistulas (AVFs) are reported. The technique presented utilizes the local instillation of tissue plasminogen activator (TPA) in small doses together with manual maceration to dissolve clot and balloon angioplasty to correct the underlying stenoses. Since the minimum dose of TPA necessary to successfully perform thrombolysis of a natural vein fistula had never been determined, an attempt to use as minimal a dose of TPA as possible was made. Five procedures were performed in fistulas which had previously undergone a thrombolysis procedure with TPA. The procedures were successful in 92% of cases with an average dose of TPA required of 2.3 +/- 0.32 mg/procedure. In addition to the 20 accesses in this article, we offer follow-up life table data on 15 fistulas that were previously reported for a total of 35 accesses salvaged with pharmacomechanical thrombolysis. Primary patency was 11.2 months and secondary patency was 25 months. Fifty-five percent of fistulas required repeat angioplasty procedures at an average of 3.6-month intervals. In addition, more than half of the fistulas that presented with clotting required repeat interventions for continued patency. This report demonstrates the effectiveness of small doses of TPA in successful pharmacomechanical thrombolysis of clotted fistulas.