The Impact of Immediate Postoperative Vein Distention on Primary Maturation of Arteriovenous Fistulas: A Prospective Cohort Study

Background: Autogenous arteriovenous fistula (AVF) maturation is essential for effective hemodialysis access, but varies considerably among patients. Most predictors of maturation rely on postoperative assessments obtained weeks after surgery, limiting early clinical decision-making. Identifying an intraoperative marker associated with subsequent maturation behavior may allow earlier anticipation of access usability. Methods: This prospective analytical study included adult end-stage renal disease patients who underwent autogenous AVF creation with complete ultrasound follow-up at 0, 2, 4 and 6 weeks. Vein diameter was measured preoperatively and immediately postoperatively, with distention defined as the difference between these values. Follow-up ultrasound assessed vein diameter, depth and flow. Time to clinical maturation was recorded as the week the access was cleared for use. Associations were evaluated using correlation analysis, one-way analysis of variance and repeated-measures analysis, with significance set at p<0.05. Results: Eighty-two (82) patients were included and all fistulas achieved functional maturation within the study period. Immediate postoperative distention demonstrated a positive association with vein diameter and flow at 2, 4 and 6 weeks (all p<0.001), but showed no association with vein depth (all p>0.05). Patients who matured earlier exhibited greater immediate distention compared with those requiring longer maturation times (p<0.001). No meaningful differences in ultrasound parameters were observed across sex or renal disease etiologies (all p>0.05). Repeated-measures analysis showed significant changes in diameter, flow and depth over time (all p<0.001). Conclusion: Immediate postoperative vein distention is associated with subsequent structural and hemodynamic changes and earlier AVF maturation. These findings suggest that intraoperative assessment of vein distention may provide clinically useful information for anticipating maturation behavior and guiding early postoperative management.