TIMING MATTERS: COMPARATIVE OUTCOMES OF NATIVE ARTERIOVENOUS FISTULA CREATION BEFORE VERSUS AFTER INITIATION OF HEMODIALYSIS

Abstract

Background: Timely creation of a native arteriovenous fistula (AVF) is recommended as the preferred vascular access for hemodialysis (HD), yet many patients in resource-limited settings undergo AVF creation only after HD has already begun.

Objective: To compare maturation, complication, and patency outcomes between native AVFs created before versus after HD initiation.

Methods: This prospective observational cohort study was conducted at the Department of Cardiovascular Surgery, Imran Idrees Teaching Hospital, Sialkot, Pakistan (20 February 2025–29 February 2026. Of 700 consecutive patients screened, 244 meeting eligibility criteria were analyzed: 122 with pre-dialysis AVF creation and 122 with post-dialysis AVF creation. Groups were compared using t-tests/Mann–Whitney U, chi-square/Fisher's exact tests, and multivariable logistic regression.

Results: Baseline demographics and comorbidities were comparable between groups. Post-dialysis AVFs showed significantly lower functional maturation (63.1% vs. 84.4%, p<0.001), higher early thrombosis (17.2% vs. 5.7%, p=0.009) and steal syndrome (9.0% vs. 0.8%, p=0.008), markedly longer catheter dependence (median 42.0 vs. 0.0 days, p<0.001), and lower primary (45.1% vs. 69.7%, p<0.001) and secondary patency (61.5% vs. 82.8%, p<0.001). Early AVF failure was more frequent post-dialysis (36.9% vs. 18.0%, p=0.001), and post-dialysis timing remained an independent predictor on multivariable analysis (adjusted OR 3.24, 95% CI 1.71–6.15, p<0.001).

Conclusion: Pre-dialysis AVF creation is associated with superior maturation, fewer complications, and better patency than post-dialysis creation. Strengthening early nephrology referral and structured pre-ESKD vascular access planning is warranted, particularly in resource-limited settings.