What a large US registry study tells us about the timing of vascular access, and what it cannot tell us
In Vascular Access Notes #02, I asked how we should define a successful vascular access. One of the answers in the discussion was: catheter-free days.
A new study by Liu and colleagues in the Journal of Vascular Access approaches this question from a different angle. It does not ask how long an access stays open, but what difference it makes whether a patient already has a fistula or graft when dialysis begins, even if it is not yet ready for use.
The study
The authors analysed data from the United States Renal Data System (USRDS) on 214,673 adults who started haemodialysis in 2018 or 2019 and were still on dialysis after 90 days. Patients were grouped by the access used at the first dialysis session:
- Catheter only: 66%
- Catheter plus a fistula or graft that was not yet usable ("CVC-plus"): 15%
- Functioning fistula or graft: 19%
Median follow-up was 30 months. Using propensity-matched comparisons with the CVC-plus group as reference, the authors found:
- Catheter only: a 31% higher mortality hazard (HR 1.31; 95% CI 1.29–1.35)
- Functioning access: a 19% lower mortality hazard (HR 0.81; 95% CI 0.79–0.83) and more kidney transplants (HR 1.39)
- Transplantation: no difference between catheter-only and CVC-plus patients, although CVC-plus patients were waitlisted more often
The authors' conclusion: early attempts to create an access may benefit patients, even when there is not enough time left for the fistula or graft to mature before dialysis starts.
The message: don't wait.
What the study cannot show
As convincing as the size of the cohort is, the design has clear limits.
Who gets early surgery? Patients in the CVC-plus group had more often received nephrology care before dialysis (73% vs. 58% in the catheter-only group). They had also agreed to an operation in advance. The authors themselves refer to "patient activation", which registry data cannot measure. Part of the survival advantage may therefore reflect the patient rather than the fistula.
Only the first day is captured. The analysis is based on the access used at the first dialysis session. Whether and when the immature access later matured, and how many catheter days were actually avoided, is not reported. This is exactly the outcome suggested in our earlier discussion.
And in Germany?
There is no official German figure for the access used at the start of dialysis. The national quality assurance programme for dialysis (IQTIG) does, however, provide two relevant numbers for 2023:
- 38.8% of new haemodialysis patients were still not dialysed via an AV fistula or graft after 180 days.
- 25.7% of all patients on haemodialysis for at least 180 days were dialysed mainly via a catheter.
For comparison, the corresponding catheter share reported by the G-BA in 2015 was around 17%, although the definitions differ. The direction is nevertheless clear: catheter dependence is not a purely American problem.
Teamwork, and the patient
A functioning access at the start of dialysis is rarely the achievement of a single person. It requires timely referral by the nephrologist, a surgeon with capacity and experience, dialysis nurses who cannulate a new fistula with care, and a patient who is willing to undergo surgery before feeling ill. Liu and colleagues illustrate this process in a separate figure, and it is a long chain.
In my view, this is where the real message of the study lies. Early planning works only if all disciplines start talking to each other early, and if patients are involved as active partners rather than passive recipients. The patient's perspective will also be a topic at our 11th Cologne Dialysis Access Symposium on 17 December.
Conclusion
An immature fistula is not the goal. But in this large registry analysis, it was associated with better survival than a catheter alone.
Three messages:
1. Activate the patient.
2. Don't wait.
3. Start the teamwork early.
How early are your patients referred for access planning? I look forward to your feedback via the contact form or on LinkedIn.
References
1. Liu A, Song RM, Ryno J, Hammes M, Angelos P, Skolarus TA, McGill RL. Clinical significance of maturing vascular access for incident hemodialysis patients. J Vasc Access. 2026;27(6):2584–2591. doi:10.1177/11297298261461909
2. IQTIG. Bundesauswertung QS NET-DIAL, Auswertungsjahr 2024 (Erfassungsjahr 2023).
3. G-BA. QSD-RL Jahresbericht 2015 (Medical Netcare).
4. Viecelli AK, Tong A, et al. Report of the SONG-HD Consensus Workshop on Establishing a Core Outcome Measure for Hemodialysis Vascular Access. Am J Kidney Dis. 2018. doi:10.1053/j.ajkd.2017.12.003
Dr. Vladimir Matoussevitch | VascularAccessTalk
Conflicts of interest: The author declares no conflicts of interest.