Improved outcomes with a stepwise ventricular assist device strategy in Glenn physiology: A single-center experience

Patients with failing single-ventricle physiology at the bidirectional Glenn stage remain among the most challenging candidates for mechanical circulatory support. Historically, outcomes after ventricular assist device (VAD) implantation were poor with early reports describing survival as low as 30%; unique aspects of Glenn circulation may limit effective ventricular decompression and exacerbate cyanosis. More contemporary multicenter experience suggests improving survival. We evaluated the outcomes of a stepwise VAD strategy in patients with failing Glenn circulation, consisting of initial centrifugal-flow support with an oxygenator, followed by transition to durable pulsatile support.

We reviewed 9 consecutive Glenn patients who underwent VAD implantation at our institution between 2018 and 2025. Temporary centrifugal devices were used in all cases, with routine incorporation of an oxygenator in the final 7 patients. Patients demonstrating stabilization were subsequently converted to Berlin Heart EXCOR support. The primary outcome was survival to transplant.

The median age at implantation was 1.4 years (interquartile range [IQR], 1.05-2.72 years), and the median body surface area was 0.45 m² (IQR, 0.38-0.49 m²). Two (20%) were bridged from extracorporeal membrane oxygentaion. The median time from Glenn to VAD implantation was 11 months (IQR, 7-22 months). Oxygenators were used in 8 patients (80%) for a median of 4 days (IQR, 3-8 days). Seven patients (70%) underwent conversion to Berlin Heart after a median of 19 days (IQR, 15-34 days). Adverse events were universal, with a median of 3 complications per patient (IQR, 2-3), most commonly infection, bleeding, hemolysis, and hepatic dysfunction. At a median wait time of 97.5 days (IQR, 67-184 days), 6 patients (60%) underwent successful transplantation, 2 (20%) remain alive on support, and 2 (20%) died while on VAD support. The deaths occurred in the smallest patient in the cohort, who had a preexisting neurologic injury and persistently elevated Glenn pressures, and in a patient with severe pulmonary vein stenosis and fungal sepsis who was transferred in salvage condition.

A staged strategy employing temporary centrifugal-flow support with routine use of an oxygenator, followed by transition to durable pulsatile support, enabled improved survival in patients with failing Glenn circulation compared with historical outcomes. Although adverse events remained common, the majority of patients were successfully bridged to transplantation. This experience highlights the potential importance of a stepwise approach in this uniquely high-risk population and warrants validation in larger, multicenter studies.