Evaluation of Impella 5.5 access site thrombosis with cross-sectional imaging

10158 

Abstract Submission 

Jacob Watson (1), Tommaso Cambiaghi (1), Fatima Qamar (1), Therese Hoof (2), Memhet Akay (2)

(1) Houston Methodist Hospital, Houston, TX, (2) Houston Methodist, Houston, TX

Jacob Watson    -  Contact Me
Houston Methodist Hospital

Tommaso Cambiaghi    -  Contact Me
Houston Methodist Hospital

Fatima Qamar    -  Contact Me
Houston Methodist Hospital

Therese Hoof    -  Contact Me
Houston Methodist

Memhet Akay    -  Contact Me
Houston Methodist

Tommaso Cambiaghi    -  Contact Me
Houston Methodist Hospital

Objective:
The objective of this single center study was to evaluate the impact of Impella 5.5 prolonged use on the access site vessel, to determine whether prolonged use is associated with dissection or thrombosis at the insertion site.

Methods:
This retrospective observational study included all patients who underwent Impella 5.5 support between February 2020 and March 2024. Data collection included baseline demographics, risk factors, procedural details, and clinical outcomes such as mortality, complications related to Impella use and ability to wean from mechanical circulatory support. Statistical analysis included descriptive statistics and appropriate inferential tests for comparison between groups.
Patients who underwent contrast enhanced CT scan during their mechanical circulatory support with Impella 5.5 were included in the review. The images were evaluated for presence of any dissection or thrombosis (partial or complete), or any other vascular complication related to the site of Impella device insertion.

Results:
A total of 145 patients (mean age 57.7, 88% male) were treated with Impella 5.5 during the study period. 29 (20%) had cross-sectional imaging performed in the time between device insertion and its removal. 7 of these scans were without contrast and therefore excluded from final review.

Of the 22 contrast-enhanced CT scans visualizing the area of interest 6 (27%) had evidence of partial thrombosis of the subclavian or axillary artery. Notably only one of these patients (4.5%) had clinical evidence of acute limb ischemia requiring revascularization procedure. More importantly 2 (33%) of the patients with imaging evidence of vessel thrombus developed an ischemic stroke while on mechanical circulatory support. Another 1 patient with evidence of thrombus burden developed ischemic strokes after MCS discontinuation 6 months later.

Of the original 29 patients with cross-sectional imaging performed in the time between device insertion and its removal, 17 of them also had additional contrast-enhanced CT scans after removal of the Impella 5.5. These scans ranged from 1 day post removal to 7 months post removal. 2 (11.7%) of these patients had new non-flow limiting dissections at the access site vessel that were not visualized on prior imaging. 6 (35%) of these patients had evidence of non-occlusive thrombus in the axillary or subclavian artery. 1 of these (16.7%) patients with new imaging evidence of vessel thrombus developed an ischemic stroke on post device removal day 4.

Conclusions:
Thrombosis at the site of Impella 5.5 insertion is a potentially under-diagnosed complication of this mechanical circulatory support device. Performing contrast-enhanced cross-sectional imaging on patients on prolonged support may help tailor anti-thrombotic therapy and prevent clinically significant complications.

ECMO/Mechanical Support