Neurological Complications of the Lower Extremities After Femoral Cannulated Extracorporeal Membrane Oxygenation: A Systematic Review

Background Femoral cannulated extracorporeal membrane oxygenation (ECMO) has been associated with neurologic complications in the lower extremity ipsilateral to the cannulation. There is uncertainty about the prevalence of these complications and their mechanisms of development. Objective Aim of this systematic review was to investigate the prevalence of neurological complications after ECMO and to describe possible underlying mechanisms. Method A systematic literature search was performed in Medline-Ovid, Embase, Cochrane Library, CINAHL, and PEDro until April 2021 for clinical trials in English or German language which quantified neurologic complications in the lower extremity ipsilateral to the ECMO cannulation of adults. The complications had to be delimitable to intensive care unit–acquired weakness. Methodological quality was assessed by 2 independent investigators using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies of the National Heart, Lung, and Blood Institute. Results Eight observational studies were included in the synthesis. Study quality was good to fair in 88% of the papers. Overall, 47 of 202 patients (23.3%; ranging from 3% to 48% across studies) with femoral ECMO cannulation showed neurologic complications of the lower extremity ipsilateral to the cannulation. Peripheral ischemia and compression of nerves by the ECMO cannula are discussed as mechanisms of injury. Conclusion The occurrence of neurological complications after ECMO was common and can lead to long-term impairment. The mechanisms are largely unknown but currently there is no sufficient evidence for the involvement of ECMO. Standardized assessments are needed to systematically screen for neurological complications early after ECMO, to enable countermeasures and prevent further complications.