How a Dedicated Vascular Access Center Can Promote Increased Use of Fistulas
Jerry Jackson
Terry F. Litchfield

Jerry Jackson, MD,is a member of a private practice nephrology group, Birmingham, AL. He is Medical Director of the Birmingham RMS Lifeline vascular access center, a member of the American Society of Diagnostic and Interventional Nephrology, Vice-Chairman of the BOD of Network 8, and a member-at-large of the Network Forum BOD.

Terry F. Litchfield, BS, MPA, has been a renal professional for over 20 years, and is currently the Vice President of Operations for RMS Lifeline.  In addition, she has been active in outcomes research and disease management for renal disease and chronic kidney disease patients as well as a patient advocate, whose husband recently celebrated 38 years of renal replacement therapy.

Providers of dialysis care in the United States have been given a mandate to use an arteriovenous (AV) fistula as the vascular access for the majority of patients with End Stage Renal Disease (ESRD). On March 17, 2005, the Centers for Medicare and Medicaid Services (CMS) announced that the Fistula First (FF) program had been elevated to the status of “Breakthrough Initiative,” giving it the top level of priority (CMS, 2005). While the National Kidney Foundation (NKF) (2001a) published guidelines in the Kidney Disease Outcomes Quality Initiative (K/DOQI) recommend that 40% of prevalent patients on hemodialysis should use AV fistulas for their vascular access, the new Breakthrough Initiative sets the target even higher, to 66%. Although this may seem to be a daunting challenge, it is clearly a recommendation that has the welfare of the patient at heart and is to be applauded.

Clinical studies have shown that the use of AV fistulas results in lower rates of infection, thrombosis, and hospitalizations. Patients who have a fistula as their access have a reduced chance of death compared with those with catheters or grafts (Dhingra, Young, Hulbert-Shearon, Leavey, & Port, 2001; Paston, Soucie, & McClellan, 2002). Additionally, the use of an AV fistula has been shown to significantly reduce the global cost of caring for a patient with ESRD (Lee et al., 2002). While not the sole cause of inflammation in patients with ESRD, the presence of an indwelling catheter or synthetic graft in the circulation is clearly a potential source of inflammation (Ayus & Sheikh-Hamad, 1998). In addition, inflammation has been shown to be involved in the atherosclerotic cardiovascular disease that is so rampant in the dialysis population (Menon et al., 2003).

Despite these facts, well over 50% of incident patients on hemodialyisis begin dialysis in the United States with a catheter for access. Of those patients referred early to a nephrologist, still less than half begin dialysis with a fistula, while only rarely are those referred just before the onset of ESRD begun on dialysis using a fistula. In great part due to efforts of the Network organizations, to CMS, and especially the National Vascular Access Improvement Initiative (the group that developed the Fistula First program), more and more patients in the U.S. are getting fistulas placed; but at present the national prevalence is only around 34%. There is great regional variation, with some areas below 30% and others over 40%. This suggests there are still substantial barriers to fistula use. Some of the factors include the aging population on dialysis in the U.S., the high prevalence of diabetes, obesity, presence of vascular disease, female gender, African-American race, the preference and training of surgeons, the preference of patients, and the lack of a coordinated vascular access management program.

Several authors have written much about the improvement in vascular access outcomes by having an integrated vascular access management program in place (Allon & Robbin, 2002; Beathard, 2003; Duda et al., 2000; Sands & Perry, 2003). This involves many things and requires much willpower and effort to establish. Components of such a program include education of referring primary care physicians, patient education, early referral to vascular surgeons, vessel mapping prior to surgery, the presence of an interventional facility whose staff is well educated in the needs of both the dialysis clinics and patients on dialysis as well as knowledgeable about proper techniques to assist fistula maturation and salvage, and a program of access monitoring and surveillance coupled with proper protocols for referral when necessary. Given the scope of a vascular access management program, having a vascular access coordinator position within a dialysis system is felt to be essential for success (Allon et al., 1998). The purpose of this article is to describe how one component of this integrated vascular access management system – the dedicated vascular access center (VAC) – can be extremely beneficial in both increasing the prevalence of fistulas and making them more usable.

How a Vascular Access Center Operates As Part of a Quality Management Program
A dedicated VAC is a facility specializing in radiographic imaging and interventional procedures required for the vascular access care of patients with ESRD. It can be hospital or office based, but is generally more cost-effective as an outpatient facility. It provides care for the patient who is pre-ESRD (with chronic kidney disease) as well as for the patient with ESRD. It functions best when it exists as part an integrated vascular access management program. It is to be emphasized that the VAC is only one component of the vascular access management program that exists within a given dialysis system. It does not replace the role of the vascular access coordinator and it will only truly be useful if the other components of the vascular access management program are in place and strong.

It is imperative that the VAC is operated in accordance with the guidelines established by K/DOQI and Fistula First. Several of these are important to mention here. The K/DOQI tells us we should time the placement of the access well in advance of the need to initiate hemodialysis (NKF, 2001b) and that a system should be in place to maximize creation of AV fistulas (NKF, 2001a). Then, once chronic access is established, there should be a defined system in place to detect potential access problems. This should be coupled with a way to obtain diagnostic testing to confirm the problem (NKF, 2001c; NKF, 2001d).

Fistula First contains an 11-step “Change Package” (see Table 1). Taken individually or in groups, these steps have been shown to lead to increased fistula prevalence if fully adopted. Many of these steps could potentially involve the type of activities carried out in a dedicated VAC.

Change Package Step 3 calls for early referral to a surgeon for “AVF only” and suggests that the nephrologist should ensure that vessel mapping be done prior to surgery. As we will discuss for each of these FF items, this is something that can be done in a VAC. Step 6 calls for a strong effort to create a fistula in patients who already have a graft, especially if that AV graft is becoming dysfunctional. This is called a secondary AV fistula and will be discussed later. While an appropriate vein can sometimes be found by physical examination at dialysis, the information generated at the VAC while the patient undergoes intervention on the AV graft may provide more information to the surgeon. Step 7 calls for patients with a catheter for dialysis access to be considered for AV fistula creation. Vessel mapping done at the VAC can often locate blood vessels suitable for this purpose. Step 9 calls for monitoring and maintenance of AV fistulas to ensure adequate function. Having a VAC in place that can rapidly schedule a patient visit for evaluation and potential intervention is very helpful to busy dialysis clinic staff when an access problem is detected. When intervention at the outpatient VAC is well coordinated with the needs of the dialysis clinic, there are usually no missed dialysis visits. Step10 calls for education for both caregivers and patients. It is possible for the VAC to carry out continuing education activities for dialysis staff, give written and verbal feedback on the findings and intervention required after a patient referral, and also help the patient better understand their fistula and the problems that are occurring. Step 11 suggests that outcomes feedback be provided to the dialysis clinic and nephrology practice to help with ongoing improvement initiatives. As part of the service of the VAC, vascular access data are sent back to the referring clinic for use in their continuous quality improvement (CQI) activities.


Vascular Access Center Services

The general areas of service done at the VAC that are of importance to fistula establishment and usability include preoperative vessel mapping, fistula maturation procedures, fistula maintenance procedures, and identification of opportunities for secondary AVFs.

Vessel Mapping
It has been shown that knowledge of the patient’s venous and arterial anatomy prior to surgery can improve the rate of fistula placement and also increase the rate of successful development of the fistula. Silva and colleagues (1998) used preoperative ultrasonography to detect the most suitable location for a fistula. Additionally, they used a set of strict criteria of minimum arterial and venous diameters at that location before proceeding. Continuity of the venous outflow through the central veins, lack of segmental vein stenosis, patent arterial blood flow to the hand (palmar arch), and less than 20 mmHg blood pressure differential between the arms were other criteria. This group has been extremely successful with both increasing prevalence of AV fistulas and with successful maturation of fistulas after placement. It should be pointed out that this surgeon does his own ultrasonic study preoperatively. Another study by Sedlacek, Teodorescu, Falk, Vassalotti, and Jaime (2001) showed preoperative ultrasonography evaluation was associated with a working fistula in 62% of patients with diabetes.

Ultrasonography can also be used to assess whether or not a young fistula is properly developing. A study by Robbin and colleagues (2002) looked at the developing fistula by Doppler ultrasonography. They found that the chance of usability at dialysis was much greater if the diameter of the fistula was 0.4 cm or more. Also, it was greater if the intrinsic blood flow rate through the AV fistula was 500 ml/min or more. If both were present, then the fistula was usable in 95% of cases. But in 80% of cases, an experienced nurse at the dialysis clinic, well trained in AV fistula physical examination techniques, could discern whether or not the fistula was developing well.

Patients may be referred to a VAC for preoperative mapping by either the nephrologist or surgeon. Prior to the procedure, a directed vascular history and physical examination should be carried out. During the directed vascular history, the clinician should inquire about a history of previous subclavian vein catheter insertion, shoulder or clavicle trauma, pacemaker insertion, smoking, prior ischemic events, and diabetic status. The physical examination should look for strength of arterial pulsation, presence of abnormal venous distribution, extremity edema, and blood pressure in each arm. An Allen test can be done to test arterial flow in the hand. The vessel mapping can be done either as a venogram with contrast, by ultrasonography, or with a combination of each.

The disadvantages of contrast venography include the potential for an acute worsening of intrinsic renal function in the patient prior to initiation of dialysis, allergic reactions, and the lack of arterial study. Yet some surgeons prefer this technique since the entire length and continuity of the venous drainage can be well seen. The ultrasonic study requires more operator expertise and more procedure time, but it yields quality information about both the arterial and venous circulation. If suitable fistula anatomy in one extremity is lacking, then bilateral vessel mapping should be done. Both a written report and copies of images from the study should be sent to the surgeon. The patient should be instructed to not allow any further venipunctures in the selected extremity. The physician operator of the VAC should be committed to fistula creation whenever possible, be knowledgeable about surgical options, and look diligently for all fistula possibilities.

It should not be forgotten that vessel mapping is useful even if the patient is already on dialysis. Despite the fact that initiation of hemodialysis with a catheter is a very undesirable option, the reality is that it occurs in over half of patients in the United States. There has been a tendency to place only a graft in those patients because of the time to maturation for a fistula. But Fistula First’s Step 7 in the Change Package suggests we attempt to place a fistula even in those patients. Vessel mapping can potentially find a location for an excellent fistula. Sands, Espada, Ferrell and Lazarus (2001a) showed that 65% of patients who receive hemodialysis with a cuffed catheter have suitable vessels for AV fistula creation. Once a fistula is placed, maturation techniques as described below can shorten the time of first use. This approach should be coupled with a strict protocol at the dialysis clinic of catheter management and quality control. The referral for vessel mapping should occur shortly after initiation of dialysis to keep the total time of catheter usage as short as possible. But given the long-term benefits of a fistula compared to any other type of access, this controlled time of exposure to a catheter might be reasonable. Again, it is to be emphasized that the most desirable situation is for a patient new to dialysis is to start dialysis with a fistula, not a catheter.

Another situation in which vessel mapping is useful in a patient already receiving dialysis is when the AV graft access is failing. Sands Espada, Ferrell and Lazarus (2001b) showed that 73% of such patients had vessels suitable for AV fistula creation. A fistula that is created in a patient with an existing AV graft is referred to as a secondary fistula. It usually is located in the venous outflow of the AV graft, but a secondary fistula can also be one placed in an extremity other than that of the AV graft. The most likely situation is that the long-term presence of a forearm graft has caused the upper arm outflow vein to greatly dilate and become arterialized. This may already be known at the dialysis clinic because it is visible by physical examination (“sleeves up exam”) or at the VAC by venography done during salvage procedures for the graft. Beathard (2004) emphasizes that it is one of the roles of the operator of a VAC to identify suitable vessels and begin the process of having a secondary AV fistula created.

Often a fistula created in this type vessel needs little or no maturation time after surgery. Some patients who have had multiple failed grafts can be found to have a forearm vein capable of fistula development. An example would be the forearm basilic vein, located in the medial aspect of the forearm, which has been missed in earlier evaluations. It can be transposed to either the proximal (loop formation) or distal radial artery, often with success. Or the vein for the new fistula might be found in another extremity. A group in Olympia, Washington lead by Dr. Nguyen has had great success in increasing their fistula prevalence mainly through the technique of secondary AVF creation (Nguyen, Tomford, Jackson, & Griffith, 1999; Nguyen, Griffith, & Robinson, 2001). The main point is that the providers of care need to be constantly thinking about the possibility of fistula creation and looking at all reasonable options. Having a VAC operated as part of a comprehensive vascular access program makes this much more likely to occur.

Maturation Procedures
Assessment of the maturation rate of a young fistula should be started at the clinic, not in the VAC. Physical examination is often sufficient to judge whether or not the access is maturing properly. Physical examination of the vascular access has been described by Beathard (1998; 2002). Keep in mind that the flow rate in the AV fistula at 4 weeks postoperatively is close to its maximum value (Yerdel et al., 1997). However, the wall of the vein has not become arterialized at that point. It has been suggested that 12 weeks is a reasonable time for an anatomically normal fistula to mature to time of first use. Therefore, if the development of the fistula, as judged by physical examination, is lagging at 8 weeks, or if other aspects of the physical examination are abnormal, it would be reasonable to refer the patient to the VAC at that point for study of the fistula and possible maturation intervention.

At the VAC, a fistulogram can be carried out. The entire vascular circuit should be examined in this study. This would include the native artery above the anastamosis, the anastamosis, the juxta-anastamotic segment, the main fistula channel, the outflow veins, and the central veins. Also, the presence of accessory veins would be noted, as well as whether or not compression of them caused a significant increase in flow in the fistula. Abnormalities in any of these areas could be the cause of reduced blood flow and delayed maturation of the fistula. Statistically, the most likely source of a problem at this stage is stenosis of the juxta-anastamotic area (Romero et al., 1986). This segment is immediately downstream from the arterial anastamosis and has usually required mobilization or “swinging” by the surgeon at the time of the fistula surgery. It is not fully understood why stenoses are so typical there, but if present the stenosis will limit blood flow into the vein that is to become the fistula and it will not properly enlarge and undergo arterialization.

It has been demonstrated that angioplasty of the early fistula is not only safe but leads to increased longevity of the AVF (Beathard, Arnold, Jackson, Litchfield, & Physician Operators Forum of RMS Lifeline, 2003; Beathard, Settle, & Shields, 1999). In a study of 100 patients with new AV fistulas and delayed maturation, angioplasty was carried out in 72 patients and obliteration of accessory veins in 43 patients. Juxta-anastomotic stenoses were present in 43 patients while stenoses higher in the fistula, outflow vein, or central veins were present in 45 patients. After these interventions, 92 of the patients were able to undergo hemodialysis using the AV fistula. After 3 months post-intervention, 84% of the fistulas were still functional, while at 6 months this was down to 72% and at 12 months to 68%. Our approach for juxta-anastomotic stenoses involves staged, sequential angioplasty. The vein is very delicate at this stage and can be easily damaged, so the angioplasty cannot be overly aggressive. Usually only a 4 mm balloon is used at the first intervention. Then, after a 2-3 week time interval, the patient returns to the VAC for further angioplasty using a slightly larger balloon. Often this is enough to see rapid maturation of the AVF, allowing use for dialysis within a few more weeks.

Ligation and coil-obliteration of accessory veins are procedures done at the VAC to help in fistula maturation (Faiyaz, Abreo, & Work, 2002), but these are more controversial (Turmel-Rodrigues et al., 2001). Occlusion of such veins may result in a dramatic increase in size of the main fistula channel. In that case, the accessory vein probably should be obliterated. But if there is any obstruction to venous outflow, correction of it with angioplasty usually causes blood flow through the accessory vein to greatly diminish. Whether or not to obliterate these veins requires great judgment on the part of the proceduralist and can wait until one sees the effect of angioplasty.

Maintenance of AVFs
The remaining category of procedures used by a VAC in promotion of AV fistulas is that of maintenance of well-matured AV fistulas. Even though AV fistulas have fewer problems than AV grafts, they can develop stenoses over time or can occasionally clot. The dedicated VAC has expertise in carrying out corrective angioplasty and, if necessary, thrombectomy. It is the role of caregivers in the dialysis clinic to monitor AV fistulas for signs of dysfunction. Here again, physical examination is most important and should be taught in the clinics. Abnormal parameters measured during the dialysis process can also lead to suspicion of fistula dysfunction. Examples would include abnormally high negative pre-pump pressures, high venous pressures, evidence of recirculation, reduced intrinsic blood flow rate in the fistula, and decline in urea kinetics. A trend of deterioration in one of these parameters is more significant than one isolated abnormal value. Monitoring in the dialysis clinic has been shown to reduce costs as well as morbidity for the patient with ESRD (McCarley et al., 2001). Lok and Oliver (2003) present an excellent discussion of monitoring of access function as well as operation of a CQI program for access management.

Abnormal findings would then trigger a referral for study at the VAC. The actual procedures for fistula maintenance are similar to those of maturation, but the location of stenoses varies from that of the early fistula. And since the fistula is now well established, the angioplasty can be more aggressive, rather than using the staged sequential approach. Tessitore and colleagues (2003) showed prospectively that angioplasty for stenoses in AV fistulas resulted in prolonged survival of the AV fistula as well as a reduction in hospitalization rate, catheter use, and thrombotic events. Thrombosis of the AV fistula can occur, and when it does, an effort should be made to restore flow rather than abandoning it. Turmel-Rodrigues et al. (2000) showed a high rate of success in carrying out thrombectomy in AV fistulas.

Our VAC Experience

To illustrate, we will describe our VAC, how it fits into our system of care for the patient with ESRD, and show, as an example, our activity relating to AVF promotion, maturation, and maintenance during the past year.

Our VAC is part of the RMS Lifeline, Inc. group of centers and is located in Birmingham, Alabama. It is operated as part of a community-based practice consisting of 10 nephrologists who care for over 800 patients with ESRD and who follow a large group of patients prior to the initiation of dialysis. Four of those nephrologists carry out all the interventional procedures at this VAC. Our VAC outcomes data was part of a study demonstrating that nephrologists as interventionalists obtain safe and effective results (Beathard, Litchfield, & Physician Operators Forum of RMS Lifeline, 2004). Each nephrologist who works in this VAC also participates in patient care in the clinic and in hospital settings, thereby not losing touch with the more traditional aspect of nephrology. All our interventionalists are committed to the tenets of the Fistula First program and see their role in the VAC as an extension of good overall care for the patient. Patients are referred to the VAC from the dialysis clinics as well as from the pre-dialysis clinic and the hospital. As seen in Table 2, during the past year we carried out vein mapping in 220 patients at the VAC. The findings from these studies were communicated to either the patient’s primary nephrologist or directly to the surgeon. Whenever possible, we encouraged AV fistula construction. Additionally, we have just instituted a program to identify patients who are suitable for a secondary AVF creation. Such patients have an identifier placed on their chart and will be referred for fistula construction when there is evidence of increasing dysfunction of the AV graft. Additionally, each interventionalist understands that angioplasty should be avoided in the identified outflow vein in order to avoid injury of the vessel wall.

As can be seen, 89% of the patients studied had not yet started dialysis, consistent with both K/DOQI and Fistula First guidelines. Unfortunately, at the time of this writing, we do not have follow-up data on the types of surgical procedures done. But we are seeing a steady increase in both incident and prevalent fistulas and hope to publish outcome data later.

Table 3 and Table 4 show details of our work in patients with existing AVFs. We carried out 427 interventional procedures in 207 individual patients, a ratio of 2.06 procedures per patient. However, excluding the Venogram Only category, this resulted in 1.63 procedures per patient during 2004. Of the total, 46% were considered maturation procedures, and 54% were considered maintenance procedures. (If intervention was carried out within the first 6 months after initial surgery for fistula creation, it was considered a maturation intervention. Those after 6 months were considered maintenance.) The data is subdivided by type of fistula. Although not shown, the overall complication rate was 1.9% with all of these being minor complications and none resulting in loss of the AV fistula or requiring surgical intervention or hospitalization.

The maturation procedures included venography, angioplasty, thrombectomy, and accessory vein ligation. If listed as a venogram, then no other type of intervention was done at that visit. Potential outcomes after venogram included notification of the dialysis clinic that the fistula was ready for use, that the fistula was progressing well but needed more time for development, or that there was a problem requiring surgical intervention. In the latter case, a surgical referral was made directly from the VAC. Angioplasties included both arterial and venous angioplasty. The staged sequential approach for maturation of early fistulas required multiple procedures over time, partially explaining the relatively high number of interventions per patient. Thrombectomies were fortunately a rare event in this early fistula population. For these more recently created fistulas, we are seeing an even distribution between radial-cephalic (forearm) and brachial-cephalic (upper arm) types. There has been a slight increase in the transposition type of AV fistulas. The “Other” category includes several forearm basilic vein transposition AV fistulas.

Maintenance procedures bear more scrutiny. These occurred in patients more than 6 months postoperatively. Review of the medical literature would suggest that fistulas require far fewer interventions than grafts to maintain patency. Our program has been strongly encouraging fistulas only since 2003, so it is possible that further surgical experience will result in fewer problematic AV fistulas. Additionally, all our vessel mappings in 2004 were of the contrast venography type. The addition of Doppler ultrasonography is anticipated and this could give additional benefits. Our number of brachial-basilic transposition AV fistulas is not large enough in the maintenance group to draw firm conclusions, but from this preliminary data it would appear that in our practice the brachial-cephalic fistula has been more problematic than other types. The radial-cephalic AV fistulas required 1.68 interventional procedures per patient during the year (non-actuarial analysis) while the brachial-basilic transposition types fistulas required 1.30 and the brachial-cephalic types required 1.89. In a study by Oliver, McCann, Indridason, Butterfly, & Schwab (2001) comparing brachial-basilic transposition fistulas to brachial-cephalic fistulas, the former were more prone to clotting and stenosis, different than our preliminary results, but not enough so to draw firm conclusions. It will be interesting to see if our results change over time.

Conclusions
AV fistulas are by far the more healthy form of vascular access for patients on hemodialysis. CMS is encouraging a fairly rapid increase in the prevalence of this type access at our dialysis clinics. Achieving this end result will be difficult and will require a rational and methodical approach with variation in the program for each practice situation. The presence of an integrated vascular access management program is of utmost importance. Part of this program requires that there be a diagnostic and treatment center willing and able to care for that particular patient’s specific problem. The burden of finding the physician and facility for referral often falls on the patient’s caregiver at dialysis. The dedicated Vascular Access Center has the attributes of rapid scheduling, knowledge of best-demonstrated practices for both diagnosis and treatment, abilities in a fairly comprehensive set of skills to reach quality results, and the ability to carry out those treatments with an acceptably low complication rate. Additionally, it is ideally situated to participate fully in the Fistula First program and to address many of the items in its Change Package. This activity in a well functioning VAC should promote increased prevalence of fistulas as well as increased percentages of fistulas that properly mature.

While the Fistula First program offers the prospect of tremendous improvement in dialysis outcomes over time, the rapid change from a “graft and catheter culture” to a “fistula culture” will undoubtedly result in challenges while progressing to quality fistula outcomes. If most of the community based nephrology practices are similar to ours, then we might expect the need for much more fistula maintenance intervention over the next few years, compared to those results published from academic centers during previous years.

Our VAC’s experience in 2004 was really the first full year of high volume involvement with AV fistulas. We are expanding our own vascular access management program by the addition of a vascular access coordinator and more robust data collection and analysis. Our challenge, as will be that for most dialysis practices, will be to move from simply a focus on individual problem solving to participation in vascular access continuous quality improvement. This will entail improvement in our methodology of vessel mapping, tracking of outcome data for surgical referrals, quantification of usage rates of fistulas after interventions, and increase in creation of secondary fistulas. Each of these steps will require local protocols for tracking and clinical management, and these will need to be updated over time as new information accrues. Regardless of the difficulties in reaching the goals set by the Breakthrough Initiative of CMS, it is exciting to speculate on the possibility of greatly improved outcomes for patients with ESRD through this process.

References
Allon, M., Bailey, R., Ballard, R., Deieroi, M.H., Hamrick, K., Oser, R., et al. (1998). A multidisciplinary approach to hemodialysis access: Prospective evaluation. Kidney International, 53, 473-479.

Allon, M., & Robbin, M.L. (2002). Increasing arteriovenous fistulas in hemodialysis patients: Problems and solutions. Kidney International, 62, 1109-1124.

Ayus, J.C., & Sheikh-Hamad, D. (1998). Silent infection in clotted haemodialysis access grafts. Journal of the American Society of Nephrology, 9, 1314-1321.

Beathard, G.A. (1998). Physical examination of the dialysis vascular access. Seminars in Dialysis, 11, 231-236.

Beathard, G.A. (2002). Physical examination: The forgotten tool. In R. Gray & J. Sands (Eds.), A multidisciplinary approach for hemodialysis access (pp. 111-118). New York: Lippincott Williams & Wilkins.

Beathard, G.A. (2003). Integrated vascular access management. Blood Purification, 21, 89-98.

Beathard, G.A. (2004). Interventionalist’s role in identifying candidates for secondary fistulas. Seminars in Dialysis, 17, 233-236.

Beathard, G.A., Arnold, P., Jackson, J., Litchfield, T., & Physician Operators Forum of RMS Lifeline. (2003). Aggressive treatment of early fistula failure. Kidney International, 64, 1487-1494.

Beathard, G.A., Litchfield, T., & Physician Operators Forum of RMS Lifeline, Inc. (2004). Effectiveness and safety of dialysis vascular access procedures performed by interventional nephrologists. Kidney International, 66, 1622-1632.

Beathard, G.A., Settle, S.M., & Shields, M.W. (1999). Salvage of the nonfunctioning arteriovenous fistula. American Journal of Kidney Disease, 33, 910-916.

Centers for Medicare & Medicaid Services (CMS). (2005). CMS launches breakthrough initiative for major improvement in care for kidney patients. Retrieved June 1, 2005, from http://www.cms.hhs.gov/media/press/release.asp?Counter=1386

Dhingra, R..K., Young, E.W., Hulbert-Shearon, T.E., Leavey, S.F., & Port, F.K. (2001). Type of vascular access and mortality in U.S. hemodialysis patients. Kidney International, 60, 1443-1451.

Duda, C.R., Spergel, L.M., Holland, J., Tucker, C.T., Bander, S.J., & Bosch, J.P. (2000). How a multidisciplinary vascular access care program enables implementation of the DOQI guidelines. Nephrology News & Issues, 14, 13-17.
Faiyaz, R., Abreo, K., & Work, J. (2002). Salvage of poorly developed arterio-venous fistula (AVFs) with percutaneous ligation of accessory veins. American Journal of Kidney Disease, 39, 824-827.

Lee, H., Manns, B., Taub, K., Ghali, W., Dean, S., & Johnson, D., et al. (2002). Cost analysis of ongoing care of patients with end stage renal disease: The impact of daily modality and dialysis access. American Journal of Kidney Disease, 40, 611-622.
Lok, C.E., & Oliver, M.J. (2003). Overcoming barriers to arteriovenous fistula creation and use. Seminars in Dialysis, 16, 189-196.

McCarley, P., Wingard, R.L., Shyr, Y., Pettus, W., Hakim, R.M., & Ikizler, T.A. (2001). Vascular access blood flow monitoring reduces access morbidity and costs. Kidney International, 60, 1164-1172.

Menon, V., Wang, X., Greene, T., Beck, G.J., Kusek, J.W., & Marcovina, S.M., et al. (2003). Relationship between C-reactive protein, albumin, and cardiovascular disease in patients with chronic kidney disease. American Journal of Kidney Disease, 42, 44-52.

National Kidney Foundation (NKF). (2001a). NKF-K/DOQI clinical practice guidelines for vascular access. Guideline 29: Goals of access placement – Maximizing primary AV fistulae. American Journal of Kidney Disease, 37(Suppl 1), S169.

National Kidney Foundation (NKF). (2001b). NKF-K/DOQI clinical practice guidelines for vascular access: Update 2000. Guideline 8: Timing of access placement. American Journal of Kidney Disease, 37(Suppl 1), S147-S148.

National Kidney Foundation (NKF). (2001c). NKF-K/DOQI clinical practice guidelines for vascular access: Update 2000. Guideline 10: Monitoring, surveillance, and diagnostic testing. American Journal of Kidney Disease, 37(Suppl 1), S150-S154.

National Kidney Foundation (NKF). (2001d). NKF-K/DOQI clinical practice guidelines for vascular access. Guideline 11: Monitoring primary AV fistulae for stenosis. American Journal of Kidney Disease, 37(Suppl 1), S154-S155.

Nguyen, V., Griffith, C., & Robinson, K. (2001). Graft-free hemodialysis practice is achievable despite high patient comorbid factors in a community-based dialysis program. Journal of the American Society of Nephrology, 12, 299A.

Nguyen, V., Tomford, R., Jackson, A., & Griffith, C. (1999). Should we stop revising thrombosed hemodialysis grafts? A 2-year experience at Providence St Peter Hospital Dialysis Program. Journal of the American Society of Nephrology, 10, A1085.

Oliver, M.J., McCann, R.L., Indridason, O.S., Butterfly, D.W., & Schwab, S.J. (2001). Comparison of transposed brachiobasilic fistulas to upper arm grafts and brachiocephalic fistulas. Kidney International, 60, 1532-1539.

Paston, S., Soucie, J.M., & McClellan, W.M. (2002). Vascular access and increased risk of death among hemodialysis patients. Kidney International, 62, 620-626.

Robbin, M.L., Chamberlain, N.E., Lockhart, M.E., Gallichio, M.H., Young, C.J., & Deierhoi, M.H., et al. (2002). Hemodialysis arteriovenous fistula maturity: U.S. evaluation. Radiology, 225, 59-64.

Romero, A., Polo, J.R., Garcia Morato, E., Garcia Sabrido, J.L., Quintans, A., & Ferreiroa, J.P. (1986). Salvage of angioaccess after late thrombosis of radiocephalic fistulas for hemodialysis. International Surgery, 71, 122-124.

Sands, J., Espada, C., Ferrell, L., & Lazarus, J. (2001a). 65% of patients with cuffed catheters have adequate vasculature for arterio-venous fistula creation [Abstract]. New York: National Kidney Foundation.

Sands, J., Espada, C., Ferrell, L., & Lazarus, J. (2001b). 73% of patients with prosthetic bridge grafts have suitable sites for secondary arterio-venous fistula creation [Abstract]. New York: National Kidney Foundation.

Sands, J.J., & Perry, M.A. (2003). Improving vascular access outcomes: A systems approach to eliminating structural barriers. Blood Purification, 21, 111-117.

Sedlacek, M., Teodorescu, V., Falk, A., Vassalotti, J.A., & Jaime, U. (2001). Hemodialysis access placement with preoperative non-invasive vascular mapping: Comparison between patients with and without diabetes. American Journal of Kidney Disease, 38, 560-564.

Silva, M.B., Hobson, R.W., Pappas, P.J., Jamil, Z., Araki, C.T., & Goldberg, M.C., et al. (1998). A strategy for increasing use of autogenous hemodialysis access procedures: Impact of preoperative noninvasive evaluation. Journal of Vascular Surgery, 27, 302-308.

Tessitore, N., Mansueto, G., Bedogna, V., Lipari, G., Poli, A., & Gammaro, L., et al. (2003). A prospective controlled trial on effect of percutaneous transluminal angioplasty on functioning arteriovenous fistulae survival. Journal of the American Society of Nephrology, 14, 1623-1627.

Turmel-Rodrigues, L., Mouton, A., Birmele, B., Billaux, L., Ammar, N., & Grezard, O., et al. (2001). Salvage of immature fistulas for haemodialysis by interventional radiology. Nephrology Dialysis Transplantation, 16, 2365-2371.
Turmel-Rodrigues, L., Pengloan, J., Rodrigue, H., Brillet, G., Lataste, A., & Pierre, D., et al. (2000). Treatment of failed native arterio-venous fistulae for hemodialysis by interventional radiology. Kidney International, 57, 1124-1140.

Yerdel, M.A., Kesenci, M., Yazicioglu, K.M., Doseyen, Z., Turkcapar, A.G., & Anadol, E. (1997). Effect of haemodynamic variables on surgically created arteriovenous fistula flow. Nephrology Dialysis Transplantation, 12, 1684-1688.