Comparison of two ultrasound guided approaches for axillary vein catheterization: a randomized controlled non-inferiority trial

Background: Axillary vein catheterization via a distal approach is an alternative to the proximal approach to axillary/subclavian vein catheterization under ultrasound (US) guidance. The aim of this trial was to compare the two approaches.

Methods: In a randomized single-centre study, all patients requiring central vein catheterization in intensive care or the operating room were randomly assigned to proximal or distal approach groups. If catheterization failed after two attempts using the approach allocated, the non-allocated approach was used. The primary endpoint was the initial success rate of distal to compared with the proximal approach, using a non-inferiority analysis (lower limit 90% CI greater than -8% non-inferiority margin for group difference). The secondary endpoints were: overall success rates, catheter position and complications.

Results: 119/122 included patients were analysed (57 and 62 in the proximal and distal axillary approach groups, respectively). Primary success rates for proximal and distal sites were 87.7 and 85.5%, respectively (difference -2.2%, 90% CI [-12.5-8.1%], non-inferiority P=0.18). The proximal and distal overall success rates were 96.5 and 98.4%, respectively (difference -1.9%, 90% CI [-4.9-8.7%], non-inferiority P<0.01). Thrombogenic catheter positions were 7 (12.3%) in proximal approach group vs 19 (31.7%) in the distal approach group (P=0.01). Complications were comparable in the two groups (2 (3.3%) vs 4 (6.5%), P=0.68).

Conclusion: In terms of absolute and overall success rates, a distal approach is not non-inferior to a proximal approach. Although associated with a more thrombogenic catheter extremity position, the distal approach can be considered as a rescue alternative after failure of a proximal approach.

Clinical trial registration: ClinicalTrials.gov identifier: NCT01543360.