Smoking is associated with a higher complication and failure rate in arteriovenous grafts for haemodialysis: A multi-centre experience

Abstract

Introduction: Arteriovenous grafts (AVG) for haemodialysis (HD) access are recommended as a second line modality due to higher morbidity and mortality rates than arteriovenous fistulae (AVF). Smoking is already established as a risk factor in lower extremity bypass graft failure used for peripheral vascular disease, but its effect on AVGs remains unclear. We aimed to investigate the relationship of smoking on AVG outcomes. Methods: A 3 year (01/08/2015–01/08/2018) multi-centre retrospective study was carried out on patients receiving an AVG for HD. Data included patient demographics, medical history, operation, type of graft, postoperative course and primary and secondary patency rates. Statistical analyses performed were Kaplan-Meier curves and Cox’s proportional hazard regression. Results: Fifty-five AVGs were performed (1052 AVF performed) in this period. The most common complication was thrombosis (38.9%). Primary patency at 6, 12 and 24 months were 55%, 45% and 44% respectively. Secondary patency at 6, 12 and 24 months were 63%, 56% and 54% respectively. Smoking was found to be a poor prognostic factor for primary (HR 3.734 (1.818–7.668 95% CI) p < 0.001) and secondary patency (HR 6.238 (2.729–14.257) p < 0.001). Smoking was also significantly associated with graft thrombosis (HR 5.741 (2.380–13.848 95% CI) p < 0.001). Discussion: Primary patency rates are lower than previous reports whilst secondary patency is equivalent. Smoking results in a greater risk of thrombosis and poorer primary and secondary patency. This is recognised in vascular surgical grafts, but has not been previously described in AVGs for HD access. Smoking is a modifiable risk factor and as AVGs are typically used for end-stage vascular access patients. Pre-operative strategies to promote smoking cessation, including patient education and prehabilitation should be employed to improve outcomes.