Antithrombotic therapy impact on patency and bleeding complications of arteriovenous graft placement in dialysis patients

Background: Arteriovenous grafts (AVG) can be the only bailout solution for patients who require kidney replacement therapy but are unsuitable for arteriovenous fistula (AVF) creation. Currently, high-level evidence on the effectiveness and safety of antithrombotic therapy in AVG patients is scarce. Materials and methods: Following the PICO (patient; intervention; comparator; outcome) model and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, a data search of the English literature in PubMed, SCOPUS, Central Cochrane was conducted, until March 1st, 2023 (PROSPERO Protocol Number: CRD42023401785). Studies on humans with an AVG receiving any kind of antithrombotic medication, reporting on primary and secondary patency rates, and bleeding complications were included. Due to data heterogeneity, a descriptive report of the outcomes was undertaken. Results: Twelve studies, including 22,436 patients with end-stage renal disease (ESRD) and AVG were included, with patient recruitment spanning over a 41-year time-period (1982-2023). Antithrombotic factors included acetylsalicylic acid (ASA), clopidogrel, dipyridamole, warfarin, unfractioned heparin (UFH), and direct oral anticoagulants (DOACs). Ten studies reported on primary patency rates, and two on secondary patency rates. Primary and secondary patency rates (PPR, SPR) were reported better in four studies, similar in three and worse in one study, regarding patients receiving any kind of antiplatelet therapy. Anticoagulation therapy was not associated with increased PPR or SPR, except for one study on apixaban. Patients receiving single or combined antiplatelets versus patients receiving no treatment presented higher bleeding risk in two studies and similar bleeding risk in three studies. Anticoagulation therapy, excluding apixaban, was associated with higher bleeding risk in three studies, when compared to no anticoagulation. Conclusions: Data derived from the current literature were equivocal regarding the use of antiplatelet treatment in patients with AVG. Studies on anticoagulation therapy are confined. Randomized trials with confounder stratification remain crucial for robust long-term data.