2007 Abstracts: Autologous Access For Dialysis: Does DOQI Have the Answer?

Background: In 2001, approximately 300,000 individuals underwent hemodialysis and the numbers continue to rise. Effective and durable hemodialysis vascular access is the goal for any surgeon caring for these patients. Unfortunately complications associated with hemodialysis access are the most common reason for hospitalizations in this patient population. There is no absolute algorithm in creating hemodialysis access.
The Dialysis Outcomes and Practice Patterns Study (DOPPS), a prospective observational study spanning 7 countries, demonstrated significant differences in the creation and use of hemodialysis access between the United States and Europe. In Europe, 80% of newly created hemodialysis accesses are arteriovenous fistula (AVF), compared to 30 % in the U.S. In addition, 80% of hemodialysis is performed via an AVF, compared to 24% in the U.S. AV grafts were most commonly utilized as hemodialysis access in the U.S. (58%).
In 2001, The National Kidney Foundation (NKF), as part of the Dialysis Outcomes Quality Initiative (DOQI), published hemodialysis vascular access guidelines. A panel of experts deemed that the creation of AVF should be the goal. Specifically, an AVF should be the access of choice if undergoing a first-time permanent hemodialysis access procedure and the guidelines propose a goal of having 40% of hemodialysis treatments via an AVF. Of note, this is based on level III evidence.
The NKF-DOQI recommendation has lead to an increase in AVF procedures. Ascher et al. reviewed a single center experience of hemodialysis access procedures pre- and post-NKF-DOQI. Their experience showed a highly significant increase in AVF creation (5% vs. 68%, p<0.001). In addition, they reported a significant increase in primary patency at one-year between AVF and AV grafts (85% vs. 54%, respectively, p<.001). These results certainly support the NKF-DOQI guidelines. Unfortunately the report does not mention the rate of actual utilization of the AVF for dialysis.
The prevalence of hemodialysis will continue to increase as the population ages and hemodialysis access will significantly contribute to morbidity, hospitalizations, and resource utilization. At this time, it seems an AVF is the top access choice among most vascular surgeons. This study examines the natural history of AVF in patients whom require first-time permanent hemodialysis vascular access, within a large academic open and endovascular vascular surgery practice.
Methods: This is a retrospective review of patients undergoing AVF creation, in which this is the first-time permanent hemodialysis access procedure performed between January, 2005 and June, 2005. The practice consists of 14 board-certified vascular surgeons and 1 board-certified transplant surgeon, all of whom have expertise and are credentialed in endovascular techniques. Charts were reviewed for patient demographics, co-morbidities, procedural details, and postoperative outcomes. Follow-up was one year. All preoperative evaluation, operations, and post-operative follow up were performed by surgeons in the practice. All subsequent endovascular and open interventions on AVF were performed by the surgeons in the practice. A patent AVF was defined as one that has a palpable thrill on clinical exam. A functioning AVF was defined as one that was patent and was being cannulated at the end of the follow up. An abandoned AVF is one which was left in place or ligated and the patient received a permanent access at another location. A percutaneous procedure was defined as being performed in an operating room or angiosuite and all parts of the procedure were performed via an access sheath. An open procedure was defined as being done in the operating room via an incision but could also have a portion performed in a percutaneous fashion. Differences between groups were analyzed using a chi-squared statistical analysis.
Results: In this six month period, a total of 383 new hemodialysis access procedures were performed, which included AVF, prosthetic grafts, and vein transpositions. Out of this group, 81 were AVF which were first-time permanent access procedures. Mean age was 59 years and 55 patient were male (67.9 %). In this group, ethnicities included 31 whites (38.3 %), 45 African-Americans (55.5%), 2 Latinos (2.5 %), and 3 Asians (3.7 %). Nearly all patients had a history of hypertension (96.3 %), with 27 requiring one medication (34.6%), 28 requiring two medications (35.9 %), and 23 requiring three medications (29.5 %) for blood pressure optimization. Forty-four patients had diabetes (53.6 %), with 21 managed by diet or oral medications and 23 requiring insulin. Twenty-four patients reported either current tobacco use or tobacco use within the last 10 years (29.6 %). Sixty-eight patients (83%) were receiving hemodialysis via a transvenous catheter at the time of AVF creation.
At initial evaluation, 62 patients had a pre-operative duplex ultrasound evaluation of the upper extremity veins (76.5%). The mean smallest diameter was 0.23 cm and the mean largest diameter was 0.41cm. There were 26 radiocephalic fistulas (32.1 %) and 55 brachiocephalic fistulas (67.9 %).
At one year, there were 5 deaths (6.1%) and 4 patients were lost to follow-up. Seventy-two patients are included in the follow up analysis (88.9%). In this group, 43 AVF were patent (59.7 %), 36 were being cannulated (50 %), and 29 (40.3%) were abandoned. There were 25 radiocephalic fistulas and 47 brachiocephalic fistulas remaining. Average time until an AVF was accessed was 181 days.
A total of 82 interventions were performed in 47 patients. There were 57 percutaneous and 25 open procedures. Of the patients requiring intervention, the indications included poor maturation (48.7 %), poor performance on dialysis (17 %), high venous pressures (13.4 %), thrombosis (11%), arm edema/infiltration (7.3 %), steal syndrome (1.3 %), and aneurysm (1.3 %). In regards to the number of overall interventions performed, 26 patients received one (55.3 %), 12 patients received two (25.5 %), 4 patients received three (8.5%) and 5 patients received four (10.7 %).
In the 36 patients with AVF which were being cannulated at one year, 10 received no interventions (13.3 %), 14 had one intervention (38.9 %), 7 had two interventions (19.4 %), 2 had three interventions (5.6 %), and 3 had four interventions (8.3 %). The most common percutaneous intervention was transluminal angioplasty and the most common open procedure was ligation of branch veins. In the 29 patients with abandoned AVF, 13 had no interventions (44.8 %), 9 had one intervention (31 %), 4 had two interventions (13.7 %), 1 had three interventions (3.4 %), and 1 had four interventions (3.4 %).
In the radiocephalic AVF subgroup, 14 remained patent (56 %) and 11 were abandoned (44 %). In patients with a patent radiocephalic AVF, 3 received no intervention and 11 had one or more interventions. In the brachiocephalic AVF subgroup, 29 (61.7 %) were patent and 18 (38.3 %) were abandoned. In patients with patent brachiocephalic AVF, 10 received no intervention and 19 received one or more interventions, which was not significant compared to the radiocephalic group. The patients with function AVF requiring no interventions consisted of 2 radiocephalic AVF and 8 brachiocephalic AVF.
There were 41 patients who were age 59 years or less. In this subgroup, there were 26 AVF patent, 15 AVF abandoned, and 22 AVF functioning at one year. There were 31 patients who were age 60 or greater. In this subgroup 17 AVF were patent, 14 AVF were abandoned, and 14 AVF were functioning at one year. There was no significant difference between these groups.
Conclusions: The spirit of the DOQI recommendations is clear and the goal of hemodialysis access surgery is to create effective and durable access for a relatively ill population. Our six month experience follows a group of patients in whom an AVF is a first-time permanent access, a major recommendation of DOQI. Since this is retrospective, the patient selection was based on the clinical expertise of the operating surgeon and can be assumed that all patients were considered good candidates for an AVF. A majority of the patients also had vein mapping to plan out an optimal AVF procedure, which is another DOQI recommendation.
This well selected group of individuals underwent AVF creation by any one of the 15 board-certified surgeons who in all perform over 750 new hemodialysis access procedures per year, which should limit any operator bias. All percutaneous and open interventions were performed by the same surgeons who have expertise in endovascular techniques. Yet only 13.3 % of first-time AVF matured and functioned without any intervention. Even with interventions the maturation rate was only 50%. In addition the average time to cannulation in this group was approximately 180 days, which exposes these ill patients to the risks of having a transvenous hemodialysis catheter for an extended period of time.
While the DOQI guidelines encourage AVF creation for first-time permanent accesses, in our experience, a significant portion of AVF will fail or not mature even with aggressive intervention. A new paradigm for first-time permanent access creation may be necessary.