Pre-operative ultrasound mapping before arteriovenous fistula formation: an updated systematic review and meta-analysis

BACKGROUND

Arteriovenous fistula represents the preferred vascular access for patients with kidney failure requiring hemodialysis. Surgeons have traditionally used physical examination to identify the most suitable vessels. This meta-analysis aims to evaluate whether ultrasound mapping should be routinely performed before arteriovenous fistula creation.

METHODS

Medline, Scopus, Web of Science and CENTRAL were systematically searched from inception to November 1, 2022. Randomized controlled trials and cohort studies comparing routine ultrasound mapping to physical examination in terms of arteriovenous fistula patency were included. Meta-analysis was performed by fitting random-effects models. The study protocol has been prospectively registered in PROSPERO (CRD42023402390).

RESULTS

Overall, 18 studies were included, comprising 3655 participants. Routine pre-operative ultrasound mapping was associated with significantly lower rates of primary arteriovenous fistula failure (Risk Ratio-RR: 0.56, 95% confidence intervals-CI: 0.37-0.84, low certainty). A significant outcome was observed by separately pooling randomized controlled trials (RR: 0.37, 95% CI: 0.25-0.54). Routine ultrasound mapping was also associated with significantly higher rates of 1-year primary arteriovenous fistula patency (RR: 1.33, 95% CI: 1.19-1.47, moderate certainty). This effect remained significant in the analysis of randomized controlled trials (RR: 1.26, 95% CI: 1.02-1.56).

CONCLUSIONS

Implementing routine pre-operative ultrasound mapping of vessels is associated with significantly better outcomes in terms of early arteriovenous fistula failure and primary patency rates at 12 months. Further research should confirm the long-term benefits of routine ultrasound examination and evaluate its cost-effectiveness in different populations.

Argatroban as an Add-On to rtPA in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Current treatment options for acute ischemic stroke, including intravenous thrombolysis (IVT) and mechanical thrombectomy, have undoubtedly revolutionized stroke care. The need for additional treatment options has brought into the light direct thrombin inhibitors (DTIs) and, specifically, argatroban as a promising candidate. However, there is uncertainty regarding the safety of adding argatroban to IVT, mainly due to the increased hemorrhagic risk. In this study, we performed a systematic review and meta-analysis examining the safety and efficacy of argatroban as an add-on treatment for IVT. The following databases were searched from inception until the 14th of May 2023: Pubmed/MEDLINE, ClinicalTrials.gov, the EU Clinical Trials Register, EMBASE/Scopus, and the Cochrane Library. Only randomized clinical trials (RCTs) enrolling patients with acute ischemic stroke who underwent IVT evaluating the add-on use of any DTIs were selected for the systematic review and further meta-analysis. The PRISMA guidelines were followed at all stages. Four studies with argatroban were included in the final analysis. Analysis of risk ratio and relative risk shows that the add-on therapy with argatroban seems to be effective and favors a good clinical outcome (mRS 0-2) at 90 days, similar to that of alteplase. All studies showed a low pooled incidence of symptomatic intracerebral hemorrhage (5%), parenchymal hematoma (3%), and other major bleeding (1%). Argatroban as an add-on treatment to IVT seems not to be associated with excessive bleeding risk; however, its efficacy remains unproven. According to this synopsis of the currently available evidence, it is premature to use argatroban as an add-on to IVT treatment outside the current clinical trial setting.

Efficacy and safety of direct oral anticoagulants vs vitamin K antagonists in patients with atrial fibrillation and end-stage renal disease on hemodialysis: A systematic review and meta-analysis

BACKGROUND

The prevalence of atrial fibrillation (AF) in individuals with end-stage renal disease (ESRD) on chronic hemodialysis is increasing. The optimal anticoagulant choice in this population is unclear since these patients were excluded from the pivotal randomized controlled trials (RCTs) of direct oral anticoagulants (DOACs) vs. vitamin K antagonists (VKAs) in the general AF population. We aimed to assess the efficacy and safety of DOACs vs. VKAs in patients with AF and ESRD on chronic hemodialysis through a systematic review and meta-analysis of all available evidence.

PATIENTS/METHODS

We performed a systematic search in MEDLINE and Scopus for RCTs or observational studies of patients with AF and ESRD on chronic hemodialysis who were treated with DOACs or VKAs. The outcomes of interest included ischemic stroke, the composite of ischemic stroke or systemic embolism, major bleeding, gastrointestinal bleeding, minor bleeding events and all-cause mortality.

RESULTS

Among 397 studies identified from the literature search, six studies (three RCTs and three observational studies) were included in the meta-analysis. Compared with VKA-treated patients, those treated with DOACs had similar risk of ischemic stroke (RR:0.76, 95% CI:0.41-1.41), ischemic stroke or systemic embolism (RR:0.65, 95% CI:0.38-1.10), major bleeding (RR:0.79, 95% CI:0.49-1.28) and all-cause death (RR:0.79, 95% CI:0.56-1.12). The risk of gastrointestinal bleeding was lower in DOAC- vs VKA-treated patients in three eligible observational studies (RR:0.73, 95% CI: 0.54-0.99, I2 = 79%) but this was not confirmed in two eligible RCTs (RR:0.69, 95% CI: 0.33-1.43, I2 = 0%).

CONCLUSIONS

Among AF patients with ESRD on chronic hemodialysis, the risk of ischemic stroke, ischemic stroke or systemic embolism, minor bleeding, major bleeding, and all-cause mortality is similar in patients treated with DOACs compared to VKAs. Given that the meta-analysis of RCTs on gastrointestinal bleeding did not confirm the results of the meta-analysis of the observational studies, it cannot be concluded that gastrointestinal bleeding is lower among DOAC-treated patients.

PROTOCOL REGISTRATION

PROSPERO CRD42023391966.