Background

Distal radial access (DRA) represents a promising alternative to conventional proximal radial access (PRA) for coronary angiography. Regarding various complications following transradial access, radial arterial occlusion (RAO) requires special attention. Despite substantial advantages have been suggested for DRA, the ideal radial access route remains controversial. Therefore, the aim of this study was to compare safety, efficacy and feasibility of DRA compared to PRA by performing a comprehensive up-to-date meta-analysis. 

Methods and Results 

National Library of Medicine PubMed, Web of Science, clinicaltrials.gov and Cochrane Library were systematically searched for randomized controlled trials and registry studies comparing DRA and PRA that were published between January 1, 2017 and September 2022. 11 randomized controlled trial studies (RCT) and 19 non-RCTs studies were identified. Primary endpoint was the rate of radial arterial occlusion (RAO). Secondary endpoints were access failure, access time, procedure time, arterial spasm, hematoma, and hemostasis time. Relative risks were aggregated using a random effects model. 

We found a significantly lower rate of RAO after DRA (DRA 1.20%, PRA 4.46%, p < .001) with a 2.79 times lower risk compared to the proximal approach (k = 30, p < .001). Selective analysis of the RCT-only subgroup did not alter the results. Conversely, the risk for access failure was 2.42 times higher for DRA compared to PRA (k = 27, p <.001). In meta-regression, the enhanced risk for access failure in the DRA group was most pronounced in studies with a low proportion of PCIs (b = -1.49, p = 0.008), while studies with >80% PCI showed no difference in the rate of access failure between groups. Proximal access was achieved 51 seconds faster on average than distal access (k = 19, p <.001 for all studies, 55sec, k = 6, p =.017 for RCTs only). Procedural time was on average 4 minutes, 25 seconds longer after DRA than after PRA, yielding a non-significant difference (k = 14, p=.122). No significant difference was also found with respect to the occurrence of arterial spasms (k = 20, p = 0.280; k_RCT = 7, p = 0.403) or hematoma (k = 22, p = 0.796, k_RCT= 7, p = 0.733). 

Conclusion

Rates of RAO are reduced with DRA compared to conventional PRA for coronary interventions. Though access failure was higher and access time longer, DRA appears to be a safe alternative to PRA.