Axillary artery access considerations in Impella 5.5insertion: Insights from exclusive axillary approach forsuccessful support.

Abstract

The Impella 5.5® is commonly inserted via the axillary artery (AX) in patients with cardiogenic shock. The right AX has traditionally been preferred to avoid crossing the aortic arch, and a minimum diameter of 7 mm has been recommended to accommodate the device (21 Fr). There is limited data on choice of laterality of access and AX size required, both in terms of technicality of the procedure as well as outcomes. We performed a single-center retrospective cohort analysis of patients who underwent Impella 5.5® implantation between December 2020 and February 2024 (N = 75). Data including demographics and outcomes were stratified both by diameter (small, <7 mm vs. normal, ≥7 mm) and laterality of access (right vs. left). Adverse events included stroke, limb ischemia, procedural bleeding or infection, and unplanned explant due to complications. Delivery time was defined as time from advancing the first wire to activation of the device. AX approach was attempted in all (N = 74) but one requiring innominate access, with a technical success rate of 95.9% (N = 71/74). The mean age was 58.8 ± 13.3 years, with 81.1% males. The median delivery time was 7.0 (25th, 75th percentiles: 4.0, 11.5) min with a median support duration of 13 (7.7, 24) days. Ten patients (13.5%) had a small AX, with a mean diameter of 6.3 ± 0.5 mm and were more likely to be younger compared to the normal AX group. Fifty-nine patients (79.7%) had insertion via the right AX. Median delivery time was comparable across all groups (small, 5.4 [3.5, 10.9] vs. normal, 7 [4.0, 12.1] min, p = 0.59) and (right, 10.4 [5.3, 15.2] vs. left, 6 [3.7, 10.4] min, p = 0.35). There was no difference between the rates of stroke, ischemia, bleeding, or infection when comparing by size or laterality. Survival to discharge was 59.5%, with 21.1% mortality on support, all in patients with a normal AX diameter, but with no difference between right versus left. In our study, laterality and a small diameter of AX access did not affect outcomes of Impella 5.5®, with a similar safety profile.