Outcomes Of Axillary-first Approach For Impella 5.5 Placement:Insights For Successful Support

Abstract

Background

Axillary artery (AA) insertion of Impella 5.5, often placed from the right side, can present unique challenges due to the need for AA diameter >7mm to accommodate the device's size (21 Fr). Left AA insertion involves crossing the aortic arch and more anatomical turns to reach the aortic valve. No data exists on the impact of small AA diameter and the laterality on Impella insertion.

Methods

We retrospectively reviewed consecutive Impella 5.5 placement patients from June 2020 to Jan 2024 at our institution (N=75), classifying patients by AA diameter (small, <7 mm vs. normal, ≥7 mm) and access laterality (left vs. right).

Results

The AA 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. Indication for Impella placement is shown in Figure. The median delivery time was 7.0 (25^th, 75^thpercentiles: 4.0,11.5) minutes with a median support duration of 13 (7.7,24) days.

Ten patients (10.6%) had a small AA, with a mean diameter of 6.3±0.5 mm and was more likely to be younger compared to normal AA with diameter of 8.7±1.2 mm. The smallest AA attempted with successful insertion measured 5.5 mm in 2 young patients. Despite the differences, the delivery time was similar (small, 5.4 [3.5,10.9]) vs. normal, 7 [4.0,12.1] min, P=0.59).

Regarding laterality of access, 59 patients (79.7%) underwent right AA implantation. The median delivery time was comparable (left, 6 [3.7,10.4) vs. right, 10.4 [5.3,15.2] min, P=0.35). Delivery failures in 3 female patients (mean age 66±3 years and AA diameter, 7.2±0.5 mm) were due to arterial calcification and tortuosity at subclavian to innominate artery or aortic arch on computed tomography, necessitating Impella CP device (N=2) or abandonment (N=1). The overall postoperative outcomes including stroke, vascular complications, infection, and hospital mortality was similar between either groups with respect to diameter as well as laterality (Table).

Conclusion

Axillary Impella 5.5 placement can be safely inserted in most patients, with adaptability in AAs <7 mm, potentially due to underestimation of diameters in shock patients and lower atherosclerosis in younger individuals. Challenges exist for older female patients with significant calcifications and tortuosity near bifurcation. Laterality of access also does not seem to influence outcomes.