An arterio-venous bridge for gradual weaning from adult veno-arterial extracorporeal life support

Abstract

Purpose: Weaning from extracorporeal life support (ELS) is particularly challenging when cardiac recovery is slow, largely incomplete and hard to predict. Therefore, we describe an individualized gradual weaning strategy using an arterio-venous (AV) bridge incorporated into the circuit to facilitate weaning. Methods: Thirty adult patients weaned from veno-arterial ELS using an AV bridge were retrospectively analyzed. Serial echocardiography and hemodynamic monitoring were used to assess cardiac recovery and load responsiveness. Upon early signs of myocardial recovery, an AV bridge with an Hoffman clamp was added to the circuit and weaning was initiated. Support flow was reduced stepwise by 10-15% every 2 to 8 hours while the circuit flow was maintained at 3.5-4.5 L/min. Results: The AV bridge facilitated gradual weaning in all 30 patients (median age: 66 [53-71] years; 21 males) over a median period of 25 [8-32] hours, with a median support duration of 96 [31-181] hours. During weaning, the median left ventricular ejection fraction was 25% [15-32] and the median velocity time integral of the aortic valve was 16 cm [10-23]. Through the weaning period, the mean arterial blood pressure was maintained at 70 mmHg and the activated partial thromboplastin time was 60±10 seconds without additional systemic heparinization. Neither macroscopic thrombus formation in the ELS circuit during and after weaning nor clinically relevant thromboembolism was observed. Conclusion: Incorporation of an AV bridge for weaning from veno-arterial ELS is safe and feasible to gradually wean patients with functional cardiac recovery without compromising the circuit integrity.