Vascular Access Patency and Complications in Patients on Maintenance Haemodialysis: A Prospective Observational Cohort Study

Abstract

Background: Vascular access failure is a leading cause of morbidity, hospitalisation and treatment interruption in maintenance haemodialysis. Prospective data on patency and complications using standardised definitions remain limited in Indian dialysis populations, in which late referral and catheter-based initiation are common. Methods: A prospective observational cohort study enrolled 160 adults on maintenance haemodialysis with a functioning vascular access at a tertiary care centre. Access type comprised arteriovenous fistula in 112, arteriovenous graft in 20 and tunnelled central venous catheter in 28 patients. Participants were followed for 12 months with clinical and duplex surveillance. Patency followed Society for Vascular Surgery reporting standards. The primary outcome was primary patency at 12 months; secondary outcomes were assisted primary and secondary patency, complications, interventions and abandonment. Kaplan-Meier and Cox regression methods were used. Results: Primary patency at 12 months was 68.8 per cent for fistulas, 45.0 per cent for grafts and 39.3 per cent for catheters (log-rank p<0.001); corresponding secondary patency was 87.5, 70.0 and 57.1 per cent. Complications occurred in 71 patients (44.4 per cent). Thrombosis was commonest in grafts (40.0 per cent) and access infection in catheters (39.3 per cent, p<0.001). On multivariable analysis, catheter use (adjusted hazard ratio 2.34, 95 per cent CI 1.29 to 4.25, p=0.005), diabetes (1.78, 1.09 to 2.91, p=0.021) and raised C-reactive protein (1.66, 1.02 to 2.71, p=0.043) independently predicted loss of primary patency. Conclusion: Arteriovenous fistulas showed clearly superior patency and the lowest complication burden. Diabetes, inflammation and catheter dependence predicted access failure, supporting early fistula creation and structured surveillance.