TITLE：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.
SOURCE: Jasty VS, Haddad D, Mohan B, et al. Tapered and non-tapered prosthetic grafts in upper extremity dialysis access: A systematic review and meta-analysis[J]. J Vasc Access, 2020 :1129729820974177. DOI: 10.1177/1129729820974177.
目的：尚不清楚在预防上肢窃血综合症时，锥形动静脉移植物（AVG）是否优于非锥形AVG。我们旨在使用系统评价和荟萃分析来评估锥形和非锥形AVG的结果。
方法：系统地进行了文献检索，以评估1999年至2019年间所有英语出版物，这些出版物直接比较了上肢锥形和非锥形AVG的结果。评估的结果是：1年时的一期通畅率（研究数（n）= 4），1年时的二期通畅率（n = 3）以及窃血（n = 5）和感染的风险（n = 4） 。使用随机效应模型汇总单个研究的效应量，并使用I2统计量评估研究之间的异质性。
结果：在筛选的5808项研究中，涉及4397例患者的5项研究符合纳入标准并纳入分析。荟萃分析显示，锥形和非锥形缺血性盗窃综合征的风险无显着性差异（合并优势比（OR）为0.92，95％可信度（CI）为0.29-2.91，p = 0.89，I2 = 48％），上肢AVG 1年时的一期通畅率（OR 1.33，95％CI 0.93-1.90，p = 0.12，I2 = 10％）和二期通畅性（OR 1.49，95％CI 0.84-2.63，p = 0.17，I2 = 13％）锥形和非锥形AVG的感染率（OR 0.62，95％CI 0.30-1.27，p = 0.19，I2 = 29％）也相似。
结论：上肢锥形和非锥形AVG的窃血综合征风险和通畅率类似。相对于非锥形移植物，该荟萃分析不支持常规使用锥形移植物以防止上肢透析通路中的窃血综合征。但是，由于研究数量少，样本量大以及基于风险因素的结果分层有限，因此未来的研究应在设计更可靠的方案以阐明此问题时考虑到这些局限性。
启发：锥形AVG的在窃血综合征、通畅率方面均无显著性优势。
