Vascular access use and outcomes: an international perspective from the Dialysis Outcomes and Practice Patterns Study.

BACKGROUND: A well-functioning vascular access (VA) is essential to efficient dialysis therapy. Guidelines have been implemented improving care, yet access use varies widely across countries and VA complications remain a problem. This study took advantage of the unique opportunity to utilize data from the Dialysis Outcomes and Practice Patterns Study (DOPPS) to examine international trends in VA use and trends in patient characteristics and practices associated with VA use from 1996 to 2007. DOPPS is a prospective, observational study of haemodialysis (HD) practices and patient outcomes at >300 HD units from 12 countries and has collected data thus far from >35,000 randomly selected patients. METHODS: VA data were collected for each patient at study entry (1996-2007). Practice pattern data from the facility medical director, nurse manager and VA surgeon were also analysed. RESULTS: Since 2005, a native arteriovenous fistula (AVF) was used by 67-91% of prevalent patients in Japan, Italy, Germany, France, Spain, the UK, Australia and New Zealand, and 50-59% in Belgium, Sweden and Canada. From 1996 to 2007, AVF use rose from 24% to 47% in the USA but declined in Italy, Germany and Spain. Moreover, graft use fell by 50% in the USA from 58% use in 1996 to 28% by 2007. Across three phases of data collection, patients consistently were less likely to use an AVF versus other VA types if female, of older age, having greater body mass index, diabetes, peripheral vascular disease or recurrent cellulitis/gangrene. In addition, countries with a greater prevalence of diabetes in HD patients had a significantly lower percentage of patients using an AVF. Despite poorer outcomes for central vein catheters, catheter use rose 1.5- to 3-fold among prevalent patients in many countries from 1996 to 2007, even among non-diabetic patients 18-70 years old. Furthermore, 58-73% of patients new to end-stage renal disease (ESRD) used a catheter for the initiation of HD in five countries despite 60-79% of patients having been seen by a nephrologist >4 months prior to ESRD. Patients were significantly (P < 0.05) less likely to start dialysis with a permanent VA if treated in a faciity that (1) had a longer time from referral to access surgery evaluation or from evaluation to access creation and (2) had longer time from access creation until first AVF cannulation. The median time from referral until access creation varied from 5-6 days in Italy, Japan and Germany to 40-43 days in the UK and Canada. Compared to patients using an AVF, patients with a catheter displayed significantly lower mean Kt/V levels. CONCLUSIONS: Most countries meet the contemporary National Kidney Foundation's Kidney Disease Outcomes Quality Initiative goal for AVF use; however, there is still a wide variation in VA preference. Delays between the creation and cannulation must be improved to enhance the chances of a future permanent VA. Native arteriovenous fistula is the VA of choice ensuring dialysis adequacy and better patient outcomes. Graft is, however, a better alternative than catheter for patients where the creation of an attempted AVF failed or could not be created for different reasons.

Enhanced training in vascular access creation predicts arteriovenous fistula placement and patency in hemodialysis patients: results from the Dialysis Outcomes and Practice Patterns Study.

OBJECTIVE: To investigate whether intensity of surgical training influences type of vascular access placed and fistula survival. SUMMARY BACKGROUND DATA: Wide variations in fistula placement and survival occur internationally. Underlying explanations are not well understood. METHODS: Prospective data from 12 countries in the Dialysis Outcomes and Practice Patterns Study were analyzed; outcomes of interest were type of vascular access in use (fistula vs. graft) in hemodialysis patients at study entry and time from placement until primary and secondary access failures, as predicted by surgical training. Logistic and Cox regression models were adjusted for patient characteristics and time on hemodialysis. RESULTS: During training, US surgeons created fewer fistulae (US mean = 16 vs. 39-426 in other countries) and noted less emphasis on vascular access placement compared with surgeons elsewhere. Significant predictors of fistula versus graft placement in hemodialysis patients included number of fistulae placed during training (adjusted odds ratio [AOR] = 2.2 for fistula placement, per 2 times greater number of fistulae placed during training, P < 0.0001) and degree of emphasis on vascular access creation during training (AOR = 2.4 for fistula placement, for much-to-extreme emphasis vs. no emphasis, P = 0.0008). Risk of primary fistula failure was 34% lower (relative risk = 0.66, P = 0.002) when placed by surgeons who created > or = 25 (vs. < 25) fistulae during training. CONCLUSIONS: Surgical training is key to both fistula placement and survival, yet US surgical programs seem to place less emphasis on fistula creation than those in other countries. Enhancing surgical training in fistula creation would help meet targets of the Fistula First Initiative.

Haemodialysis vascular access problems in Canada: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS II).

BACKGROUND: The optimal vascular access for chronic maintenance haemodialysis (HD) is the native arteriovenous fistula (AVF). Vascular access practice patterns are reported for a Canadian cohort of patients from the Dialysis Outcomes and Practice Patterns Study (DOPPS II). METHODS: DOPPS II is a prospective, observational study in 12 countries, including Canada. A representative random sample of 20 Canadian HD facilities and patients within those units were studied during 2002-2004. Canadian results were compared with those found in Europe and the USA. RESULTS: AVF use in Canadian prevalent (53%) and incident (26%) patients was lower than Canadian guidelines recommend (60%), and lower than in Europe [prevalent (74%), incident (50%)]. Despite 85% of Canadian HD patients having seen a nephrologist for > 1 month prior to starting dialysis, central venous catheter use in Canada (33% in prevalent patients, 70% in incident patients) was much higher than in Europe (prevalent 18%, incident 46%) and slightly higher than in the USA (prevalent 25%, incident 66%). This pattern is contrary to the preferences of Canadian medical directors and vascular access surgeons. The typical time from referral until permanent vascular access creation is substantially longer in Canada (61.7 days) than in Europe (29.4 days) or the USA (16 days). This longer delay time and higher catheter use in Canada may be a consequence of the significantly lower number of access surgeons per 100 HD patients in Canada (2.9) compared with the USA (8.1) and Europe (4.6). Furthermore, the median hours per week devoted to vascular access-related surgery per 100 patients is substantially lower in Canada (0.027 h) compared with the USA (0.082 h) and Europe (0.059 h). CONCLUSION: These findings suggest that Canadian chronic HD patients often rely on central venous catheters for vascular access, despite their known association with numerous detrimental outcomes in HD. Nephrologists, vascular access surgeons, interventional radiologists, other physicians and health care funding bodies must be more broadly educated about the priority of AVF creation as the preferred vascular access for chronic HD patients. They must work together to secure both the human and financial resources and other health care system enhancements to increase AVF creation rates in a timely manner.