Radial artery occlusion (RAO) is a major impediment to reintervention in patients who underwent proximal transradial access (p-TRA) for coronary catheterization. Distal transradial access (d-TRA) at the level of snuffbox distal to the radial artery bifurcation is a novel alternative to p-TRA. We conducted an updated meta-analysis of all available randomized controlled trials (RCTs) to compare the incidence of RAO between p-TRA and d-TRA, along with access site-related complications. PubMed, Web of Science, and Google Scholar were searched for RCTs published since 2017 to October 2023 comparing d-TRA and p-TRA for coronary angiography and/or intervention. Risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals were calculated using the random-effects model for procedural and clinical outcomes for the 2 approaches. A total of 18 RCTs with 8,205 patients (d-TRA n = 4,096, p-TRA n = 4,109) were included. The risk of RAO (RR 0.31, 0.21 to 0.46, p ≤0.001) and time to hemostasis (minutes) (MD -51.18, -70.62 to -31.73, p <0.001) was significantly lower in the d-TRA group. Crossover rates (RR 2.39, 1.71 to 3.32, p <0.001), access time (minutes) (MD 0.93, 0.50 to 1.37, p <0.001), procedural pain (MD 0.46, 0.13 to 0.79, p = 0.006), and multiple puncture attempts (RR 2.13, 1.10 to 4.11, p = 0.03) were significantly higher in the d-TRA group. The use of d-TRA for coronary angiography and/or intervention is associated with a lower risk of RAO at the forearm and may preserve p-TRA site for reintervention in selective patients by reducing the incidence of RAO.

Distal Versus Proximal Radial Arterial Access for Percutaneous Coronary Angiography and Intervention: Updated Meta-Analysis of Randomized Controlled Trials.

The previous meta-analysis has assessed that distal transradial access (dTRA) in anatomical snuffbox is safe and effective for coronary angiography and intervention and can reduce radial artery occlusion. However, since the publication of the previous meta-analysis, several observational studies have been added, so we performed an updated meta-analysis to include more eligible studies to compare distal transradial access in anatomical snuffbox with conventional transradial access (cTRA).
Pubmed, Embase, and Cochrane Library databases were searched for relevant studies from the literature published until 5 January 2021 to evaluate catheterization/puncture failure, hematoma, radial artery spasm, radial artery occlusion (RAO), access time, fluoroscopy time, radiation dose area product, total procedure time, and hemostatic device removal time. The pooled odds ratio (OR), weighted mean difference (WMD), and standardized mean difference (SMD) with 95% confidence interval (95% CI) were calculated for dichotomous and continuous variables, respectively.
A total of 9,054 patients from 14 studies were included in the meta-analysis, and we found no significant difference in catheterization/puncture failure (OR = 1.94, 95CI [0.97, 3.86], 
Compared with the cTRA, the dTRA has a lower incidence of radial artery occlusion and shorter hemostatic device removal time, which is worthy of further evaluation in clinical practice.

Distal Transradial Access in Anatomical Snuffbox for Coronary Angiography and Intervention: An Updated Meta-Analysis.

The distal radial artery (DRA) access is an alternative to the conventional radial artery (CRA) access for coronary angiography and interventions and appears to be associated with reduced incidence of certain outcomes.
A systematic review was performed to evaluate differences between DRA versus CRA access for coronary angiography and/or interventions. Following preferred reporting items for systematic review and meta-analysis-protocols guidelines, two reviewers independently selected studies published in the electronic databases (MEDLINE, EMBASE, SCOPUS, CENTRAL) from inception to October 10, 2022, followed by data extraction, meta-analysis, and quality assessment.
The final review included 28 studies with (total: 9151 patients [DRA: 4474; CRA: 4677]). Compared with CRA, DRA access was found to be associated with a shorter time to achieve hemostasis (mean difference, MD: -32.49 [95% confidence interval, CI: -65.53, -2.46], p < 0.00001), and reduced incidence of radial artery occlusion (RAO) (risk ratio, RR: 0.38 [95% CI: 0.25, 0.57], p < 0.00001), any bleeding (RR: 0.44 [95% CI: 0.22, 0.86], p = 0.02), and pseudoaneurysm (RR: 0.41 [95% CI: 0.18, 0.99], p = 0.05). However, DRA access has increased access time (MD: 0.31 [95% CI: -0.09, 0.71], p < 0.00001) and crossover rates (RR: 2.75 [95% CI: 1.70, 4.44], p < 0.00001). There were no statistically significant differences in other technical aspects and complications.
DRA access is a safe and feasible approach for coronary angiography and interventions. Compared to CRA, DRA provides a shorter hemostasis time, lower incidence of RAO, any bleeding, and pseudoaneurysm, and is associated with increased access time and crossover rates.

Distal versus conventional radial artery access for coronary catheterization: A systematic review and meta-analysis.

Searching the literature for coronary angiography (CAG) or intervention through distal radial access (DRA) and performing a meta-analysis.
Coronary angiography (CAG) or intervention through distal radial access (DRA) may have a similar success rate, low radial artery occlusion rate, low radial artery spasm rate, and low rate of puncture site hematoma for patients with coronary heart disease. Therefore, the randomized controlled trials (RCTs) were searched, and the data were pooled for meta-analysis to evaluate the effectiveness and safety of DRA.
RCTs comparing the CAG or intervention through DRA vs. transradial access (TRA) published between January 1, 2017, and May 4, 2021, were searched in the PubMed, Embase, and Cochrane databases. The endpoints included the rate of access success and the number of radial artery occlusions, radial artery spasms, and puncture site hematomas. The data were extracted, and a random-effects model was used for analysis.
Among 204 studies, 6 RCTs (with 2825 participants) met the inclusion criteria. Compared to TRA, the access success rate in DRA (
In summary, DRA has a similar access success rate and incidence of hematoma at the puncture site, but a lower incidence of RAO and spasm compared to TRA. These findings demonstrated that DRA is a safe and effective access for CAG or intervention.

Safety and Effectiveness of Coronary Angiography or Intervention through the Distal Radial Access: A Meta-Analysis.

Magnetic resonance spectroscopy studies measuring brain glutamate separately from glutamine are helping elucidate schizophrenia pathophysiology. An expanded literature and improved methodologies motivate an updated meta-analysis examining effects of measurement quality and other moderating factors in characterizing abnormal glutamate levels in schizophrenia.
Searching previous meta-analyses and the MEDLINE database identified 83 proton magnetic resonance spectroscopy datasets published through March 25, 2020. Three quality metrics were extracted-Cramér-Rao lower bound (CRLB), line width, and coefficient of variation. Pooled effect sizes (Hedges' g) were calculated with random-effects, inverse variance-weighted models. Moderator analyses were conducted using quality metrics, field strength, echo time, medication, age, and stage of illness.
Across 36 datasets (2086 participants), medial prefrontal cortex glutamate was significantly reduced in patients (g = -0.19, confidence interval [CI] = -0.07 to -0.32). CRLB and coefficient of variation quality subgroups significantly moderated this effect. Glutamate was significantly more reduced in studies with lower CRLB or coefficient of variation (g = -0.44, CI = -0.29 to -0.60, and g = -0.43, CI = -0.29 to -0.57, respectively). Studies using echo time ≤20 ms also showed significantly greater reduction in glutamate (g = -0.41, CI = -0.26 to -0.55). Across 11 hippocampal datasets, group differences and moderator effects were nonsignificant. Group effects in thalamus and dorsolateral prefrontal cortex were also nonsignificant.
High-quality measurements reveal consistently reduced medial prefrontal cortex glutamate in schizophrenia. Stricter CRLB criteria and reduced nuisance variance may increase the sensitivity of future studies examining additional regions and the pathophysiological significance of abnormal glutamate levels in schizophrenia.

Medial Prefrontal Cortex Glutamate Is Reduced in Schizophrenia and Moderated by Measurement Quality: A Meta-analysis of Proton Magnetic Resonance Spectroscopy Studies.

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