Refractory Hypoxemia After Left Ventricular Assist Device Implantation: Underestimated Patent Foramen Ovale and Venovenous Extracorporeal Membrane Oxygenation-Associated Sump Effect on Bubble Study.
Makoto Kataoka, Satoshi Hanada, Edwin Becher et al.
✦ AI-curated · Sources linked
Case in brief
A 63-year-old man developed severe refractory hypoxemia after left ventricular assist device (LVAD) implantation due to significant right-to-left shunting through a previously underestimated patent foramen ovale (PFO). Initially deemed mild, the PFO led to critical hypoxemia on postoperative day 1, necessitating venovenous extracorporeal membrane oxygenation (ECMO) for rescue. The case highlights the importance of reevaluating PFO significance during LVAD procedures.
What made this case unusual
The bubble study, performed during ECMO support, was confounded by the sump effect of the venous drainage cannula, leading to an underestimation of the shunt's severity.
Diagnostic / clinical pearl
Clinicians should maintain a low threshold for PFO closure during LVAD implantation, as even mild defects can pose significant risks postoperatively.
Why it matters
This case underscores the limitations of preoperative echocardiographic assessments in advanced heart failure and the potential for ECMO to obscure intracardiac shunting during diagnostic studies.