Tapered and non-tapered prosthetic grafts in upper extremity dialysis access: A systematic review and meta-analysis

Objective: It is unclear whether tapered arteriovenous grafts (AVGs) are superior to non-tapered AVGs when it comes to preventing upper extremity ischemic steal syndrome. We aimed to evaluate the outcomes of tapered and non-tapered AVGs using systematic review and meta-analysis. Methods: A literature search was systemically performed to identify all English publications from 1999 to 2019 that directly compared the outcomes of upper extremity tapered and non-tapered AVGs. Outcomes evaluated were the primary patency at 1-year (number of studies (n) = 4), secondary patency at 1-year (n = 3), and risk of ischemic steal (n = 5) and infection (n = 4). Effect sizes of individual studies were pooled using random-effects model, and between-study variability was assessed using the I² statistic. Results: Of 5808 studies screened, five studies involving 4397 patients have met the inclusion criteria and included in the analysis. Meta-analyses revealed no significant difference for the risk of ischemic steal syndrome (pooled odds ratio (OR) 0.92, 95% Confidence Incidence (CI) 0.29–2.91, p = 0.89, I² = 48%) between the tapered and non-tapered upper extremity AVG. The primary patency (OR 1.33, 95% CI 0.93–1.90, p = 0.12, I² = 10%) and secondary patency at 1-year (OR 1.49, 95% CI 0.84–2.63, p = 0.17, I² = 13%), and rate of infection (OR 0.62, 95% CI 0.30–1.27, p = 0.19, I² = 29%) were also similar between the tapered and non-tapered AVG. Conclusions: The risk of ischemic steal syndrome and patency rate are comparable for upper extremity tapered and non-tapered AVGs. This meta-analysis does not support the routine use of tapered graft over non-tapered graft to prevent ischemic steal syndrome in upper extremity dialysis access. However, due to small number of studies and sample sizes as well as limited stratification of outcomes based on risk factors, future studies should take such limitations into account while designing more robust protocols to elucidate this issue.