Relationships Between Clinical Processes and Arteriovenous Fistula Cannulation and Maturation: A Multicenter Prospective Cohort Study

Abstract

Background: Half of surgically created arteriovenous fistulas (AVFs) require additional intervention to effectively support hemodialysis. Postoperative care and complications may affect clinical maturation.

Study design: Hemodialysis Fistula Maturation (HFM) Study, a 7-center prospective cohort study.

Setting & participants: 491 patients with single-stage AVFs who had neither thrombosis nor AVF intervention before a 6-week postoperative ultrasonographic examination and who required maintenance hemodialysis.

Predictors: Postoperative care processes and complications.

Outcomes: Attempted cannulation, successful cannulation, and unassisted and overall clinical maturation as defined by the HFM Study criteria.

Results: AVF cannulation was attempted in 443 of 491 (90.2%) participants and was eventually successful in 430 of these 443 (97.1%) participants. 263 of these 430 (61.2%) reached unassisted and 118 (27.4%) reached assisted AVF maturation (overall maturation, 381/430 [88.6%]). Attempted cannulation was less likely in patients of surgeons with policies for routine 2-week versus later-than-2-week first postoperative visits (OR, 0.21; 95% CI, 0.06-0.70), routine second postoperative follow-up visits (OR, 0.39; 95% CI, 0.15-0.97), and a routine clinical postoperative ultrasound (OR, 0.28; 95% CI, 0.14-0.55). Attempted cannulation was also less likely among patients undergoing procedures to assist maturation (OR, 0.51; 95% CI, 0.27-0.98). Unassisted maturation was more likely for patients treated in facilities with access coordinators (OR, 1.91; 95% CI, 1.17-3.12), but less likely after precannulation nonstudy ultrasounds (OR per ultrasound, 0.42 [95% CI, 0.26-0.68]) and initial unsuccessful cannulation attempts (OR per each additional attempt, 0.90 [95% CI, 0.83-0.98]). Overall maturation was less likely with infiltration before successful cannulation (OR, 0.44; 95% CI, 0.22-0.89). Among participants receiving maintenance hemodialysis before AVF surgery, unassisted and overall maturation were less likely with longer intervals from surgery to initial cannulation (ORs for each additional month of 0.81 [95% CI, 0.76-0.88] and 0.93 [95% CI, 0.89-0.98], respectively) and from initial to successful cannulation (ORs for each additional week of 0.87 [95% CI, 0.81-0.94] and 0.88 [95% CI, 0.83-0.94], respectively).

Limitations: Surgeons' management policies were assessed only by questionnaire at study onset. Most participants received upper-arm AVFs, planned 2-stage AVFs were excluded, and maturation time windows were imposed. Some care processes may have been missed and the observational design limits causal attribution.

Conclusions: Multiple processes of care and complications are associated with AVF maturation outcomes.

Keywords: Vascular access; arteriovenous access; arteriovenous fistula (AVF); cannulation; end-stage renal disease; fistula maturation; hemodialysis; patency; process-of-care.

Fig 1

Cumulative incidences of attempted AVF cannulation and overall maturation after AVF creation surgery, among members of the cannulation-eligible subcohort on dialysis at the time of surgery (N=387), censored for loss to and termination of follow-up, treating kidney transplantation as a competing risk and death as a maturation failure and a competing risk for cannulation.

Fig 2

Cumulative incidences. Top panel, of successful cannulation after first cannulation attempt, among members of the cannulation-eligible subcohort for whom cannulation was attempted (N=443), censored for loss to and termination of follow-up, and treating kidney transplantation and death as competing risks. Bottom panel, of clinical AVF maturation after successful cannulation, in the successfully cannulated subcohort (N=430), censored for loss to and termination of follow-up, and treating death as a maturation failure and kidney transplantation as a competing risk.

Fig 2

Cumulative incidences. Top panel, of successful cannulation after first cannulation attempt, among members of the cannulation-eligible subcohort for whom cannulation was attempted (N=443), censored for loss to and termination of follow-up, and treating kidney transplantation and death as competing risks. Bottom panel, of clinical AVF maturation after successful cannulation, in the successfully cannulated subcohort (N=430), censored for loss to and termination of follow-up, and treating death as a maturation failure and kidney transplantation as a competing risk.

Fig 3

Analysis subcohorts and maturation-related outcomes (N=602).

Fig 4

Forest plots of statistically significant estimated odds ratios, with 95% confidence intervals, relating AVF care processes and complications to attempted cannulation and maturation. a) attempted cannulation (N=491); b) unassisted clinical maturation (N=430); c) overall clinical maturation (N=430).