A Meta-Analysis of Traditional Radial Access and Distal Radial Access in Transradial Access for Percutaneous Coronary Procedures

Distal Transradial Access Optimization: A Prospective Trial of Ultrasound-Guided Radial Artery Characterization for the Anatomical Snuffbox

Background/Objectives: The distal transradial approach (dTRA) is increasingly used in interventional cardiology. Doppler Ultrasound (DUS) effectively assesses radial artery (RA) characteristics. This study aims to identify specific RA DUS characteristics in patients undergoing coronary procedures via dTRA. Methods: Participants from the ANTARES trial who completed the intervention per-protocol and retained RA patency were included. DUS was performed at baseline, 1 day, and 60 days post-procedure. Results: Among 400 participants, 348 had either dTRA (n = 169) or conventional transradial access (cTRA) (n = 179). Distal RA lumen diameter was 12% smaller than that of the proximal RA (p < 0.001). Men had a 14% larger distal RA diameter than women (2.33 ± 0.31 mm vs. 2.04 ± 0.27 mm, p < 0.0001), similar to the proximal RA relationship. Peak flow velocities were similar between the sexes. Univariate linear regression showed that height, weight, body mass index, and body surface area (BSA) predicted arterial size, with BSA remaining significant in multivariate analysis (beta coefficient 0.62; confidence interval 0.49-0.75; p < 0.0001). Distal RA diameter correlated positively with palpable pulse at the snuffbox and wrist. The dTRA resulted in an immediate 14% and 11% increase in distal and proximal RA diameter, respectively (both p < 0.05). Sixty days after dTRA, the distal RA remained slightly dilated (p < 0.05), while the proximal RA returned to baseline. Conclusions: Distal RA diameter is significantly associated with sex, measuring smaller than the forearm segment. A strong palpable pulse correlates with larger distal RA size. The dTRA induces RA lumen expansion. A thorough understanding of distal RA anatomy is essential for optimizing patient selection and refining techniques for transradial procedures.

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

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.

How to Omit the Potential Pitfalls in Distal Radial Access: Lessons From Cadaveric and CTA Analysis

OBJECTIVES

To verify the anatomical basis, ideal puncture sites, and potential pitfalls of the distal radial artery (dRA) in the anatomical snuffbox region for distal radial access (dTRA).

MATERIALS AND METHODS

Overall, 26 formalin-fixed upper limbs and computed tomography angiography (CTA) of the upper limbs of 168 consecutive patients were studied. Cadaveric dissection and dRA 3D reconstruction were used to evaluate the dRA route for dTRA. The puncture sites, dRA diameter, and angle of the dRA and tendons of the extensor pollicis brevis were also measured in the patients and cadavers.

RESULTS

The cadaver dissection provided more insights than did the dRA 3D reconstruction. However, preoperative evaluation had better diagnostic accuracy (p=0.024). Puncture sites 1 and 3 had a high success rate (63.2% possible success rate, 191/302). The DISFAVOR theory was put forward, in which 8 types of potential pitfalls that may interrupt puncture procedure or lead to a surgical failure were observed, including occlusion, stenosis, tortuosity, arteriovenous fistula, angioma, different radial artery (RA) ramifications, radial veins, and cephalic veins. The mean diameter of dRA based on cadaver dissection and CTA was 2.53 (SD=0.73) and 2.63 (SD=0.69) mm, respectively. Furthermore, the minimum distance from the outer layer of dRA to the skin was 5.71 (SD=2.0) mm based on CTA. The angle between the dRA and tendons of extensor pollicis brevis (TEPB) based on cadaver dissection and CTA was 58.0° (SD=21.5°) and 51.8° (SD=16.6°), respectively.

CONCLUSIONS

Puncture sites 1 and 3 were more suitable for the dTRA, and we put forward the DISFAVOR theory to summarize the 8 types of potential pitfalls during the use of dTRA.

Distal radial approach for arterial pressure monitoring with a long catheter provides safe and stable monitoring in the intensive care unit: A single-center retrospective study

BACKGROUND

To compare the distal radial artery approach (DRA) with a longer catheter to DRA with a shorter catheter in arterial catheter (AC) placement in the intensive care unit (ICU).

METHODS

This was a single-center retrospective cohort study of DRA with a long catheter (60 mm) for arterial catheterization in the ICU. DRA with a short catheter (25-30 mm) was used in the control group, and the groups were compared using multivariate regression analysis. The primary study endpoint was the incidence of unplanned AC removal. The secondary endpoint was the incidence of other inappropriate events, namely loss of arterial pressure waveforms, bleeding, catheter-related infection, pressure ulcer, and other complications associated with the AC.

RESULTS

In this study, the DRA with a long catheter was used in 50 patients. No unplanned AC removals or other inappropriate events occurred, and there were no complications associated with the DRA. The DRA procedural success rate was 100%. There was no significant difference in hemostasis times between the groups. Loss of arterial waveforms was an early predictor of unplanned AC removal.

CONCLUSIONS

The DRA with a long catheter provided stable monitoring and was associated with a low unplanned removal rate. This method has the advantages of fewer complications and shorter hemostasis time compared with the DRA with a short catheter, and may become a new AC option in the ICU.

Distal Radial Approach in Coronary Angiography Using a Transdermal Nitroglycerin Patch: Double-Blinded Randomized Trial

Nitroglycerin dilates the radial artery and prevents spasm, which increases the success rate of sheath cannulation through the conventional transradial approach. However, the effects of nitroglycerin on distal radial approach (DRA) procedures are not known. The aim of this study is to elucidate whether a transdermal nitroglycerin patch improves the rate of successful DRA cannulation. A total of 92 patients scheduled for coronary angiography by means of DRA randomly received (1:1) a transdermal nitroglycerin patch preintegrated with the covering material or only the covering material on their upper arm on the side of the puncture. The diameter of the distal radial artery was evaluated with ultrasound at baseline and after application. DRA procedures were performed in a double-blind fashion. The primary outcome was the rate of successful palpation-guided distal radial artery cannulation with the first puncture. The nitroglycerin group had larger distal radial artery diameter after patch application than that of the no-treatment group (mean, 3.21 mm vs 2.71 mm, p <0.001), but not at baseline (mean, 2.64 mm vs 2.64 mm, p = 0.965).The nitroglycerin group had a significantly higher success rate of DRA cannulation with the first puncture than that of the no-treatment group (59% vs 24%, p = 0.001; odds ratio 4.5, 95% confidence interval 1.9 to 11.0). The nitroglycerin group required fewer punctures than did the no-treatment group (median, 1 vs 3, p = 0.019). There were no significant differences in the occurrence of hypotension between the 2 groups. No patients experienced radial artery occlusion. In conclusion, transdermal nitroglycerin patch application safely facilitates DRA cannulation. Trial Registration: Japan Registry of Clinical Trials, https://jrct.niph.go.jp/ (identifier: jRCTs051210128).