Utilization of Microaxial Mechanical Circulatory Support Among the Pediatric Population: A Systematic Review

Utilization of microaxial pumps for temporary mechanical circulatory support in children has increased in recent years. However, data on patient selection, implantation techniques, and outcomes remain limited.

A systematic literature search was conducted in July 2025 to identify case reports and case series reporting the use of microaxial pumps in patients aged 18 years or less. Forty-four studies comprising 100 patients were identified, and patient-level data were extracted for analysis.

The median age of the patients was 14 [IQR, 11.5-16] years, with a median weight of 52 [40-73] kg and median body surface area of 1.59 [1.35-1.85] m². The most common diagnoses were cardiomyopathy (29%), heart allograft rejection (26%), and myocarditis (21%). Impella CP was the most frequently used device (48%), followed by Impella 2.5 and Impella 5.5 (each 21%). Access was predominantly obtained via the femoral artery (47%). Percutaneous implantation was performed in 47% of patients. Patients were weaned from microaxial support for cardiac recovery (42%) or heart transplantation (31%). Fourteen patients (14%) died prior to discharge, with significantly higher mortality among patients supported with ECPella (29%) compared with microaxial pump alone (6%; p = 0.01). The median duration of support was 6 [4-13] days. At the median follow-up of 119 [23-180] days overall survival was 84%.

Microaxial pumps represent an important addition to temporary mechanical circulatory support in pediatric patients and can serve as an alternative to VA-ECMO in selected cases. Outcomes were less favorable when used in tandem configurations such as ECPella, reflecting the greater severity of illness in these patients.