Bedside repositioning of a dislocated Avalon-cannula in a running veno-venous ECMO

Bicaval dual lumen cannula placement using transthoracic echocardiography in COVID-19 scenario: pearls and pitfalls

A woman in her 50s who had been diagnosed with COVID-19 developed deep vein thrombosis in the left femoral vein extending into inferior vena cava (IVC). An IVC filter was placed to prevent fatal pulmonary embolism. Her respiratory failure subsequently deteriorated despite optimal mechanical ventilation and required venovenous extracorporeal membrane oxygenation (VV-ECMO) as a rescue therapy. Femoro-jugular VV-ECMO configuration was not suitable due to the IVC filter, hence a single-site venous cannulation using bicaval dual lumen (AvalonElite) cannula was selected. Placement of the Avalon cannula conventionally requires guidance by fluoroscopy or transoesophageal echocardiography, which were not feasible in COVID-19 patients. Hence, transthoracic echocardiography guidance was chosen. Guidewire looping into the right ventricle might lead to cannula malposition and imminent right ventricular rupture, but these could be detected by 'bending' sign. Transthoracic echocardiography could be a feasible guidance method for Avalon cannulation, nonetheless a thorough protocol should be followed to avoid cannula malposition during the procedure.

In Vitro and In Vivo Feasibility Study for a Portable VV-ECMO and ECCO2R System

Extracorporeal membrane oxygenation (ECMO) is an established rescue therapy for patients with chronic respiratory failure waiting for lung transplantation (LTx). The therapy inherent immobilization may result in fatigue, consecutive deteriorated prognosis, and even lost eligibility for transplantation. We conducted a feasibility study on a novel system designed for the deployment of a portable ECMO device, enabling the physical exercise of awake patients prior to LTx. The system comprises a novel oxygenator with a directly connected blood pump, a double-lumen cannula, gas blender and supply, as well as control and energy management. In vitro experiments included tests regarding performance, efficiency, and blood damage. A reduced system was tested in vivo for feasibility using a novel large animal model. Six anesthetized pigs were first positioned in supine position, followed by a 45° angle, simulating an upright position of the patients. We monitored performance and vital parameters. All in vitro experiments showed good performance for the respective subsystems and the integrated system. The acute in vivo trials of 8 h duration confirmed the results. The novel portable ECMO-system enables adequate oxygenation and decarboxylation sufficient for, e.g., the physical exercise of designated LTx-recipients. These results are promising and suggest further preclinical studies on safety and efficacy to facilitate translation into clinical application.

Migrated Avalon-Elite cannula in an infant transcatheter repositioning without interruption of ECMO flow

Inadvertent migration of Avalon-Elite cannula in patients receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO) support is often difficult to manage. Cannula repositioning conventionally requires temporary discontinuation of the ECMO support which is often poorly tolerated in small infants with poor pulmonary reserve. We reported a case of a small infant weighing 3.9 kg requiring VV-ECMO support with a 13Fr Avalon-Elite cannula for respiratory failure secondary to severe pneumonitis, complicated by 2 episodes of cannula migration which were both successfully managed by transcatheter repositioning in the cardiac catheterization laboratory without interruption of ECMO flow.

Safely repositioning dual-lumen ECMO cannulas with a transfemoral lasso snare

INTRODUCTION

Dual-lumen cannulas were designed to provide venovenous extracorporeal membrane oxygenation (VV ECMO) with single-vessel access. Anatomic and size considerations may make appropriate placement challenging in children. Dual-lumen cannulas are repositioned in 20-69% of pediatric patients, which can be difficult without transient discontinuation of ECMO support.

METHODS

We repositioned three dual-lumen ECMO cannulas introduced via the right internal jugular vein using a transfemoral snare technique under real-time ultrasound and fluoroscopy.

RESULTS

Two of three patients were supported on VV ECMO and one on veno-veno-arterial (VV-A) ECMO. Two of the three patients had their dual-lumen cannula repositioned under ultrasound and fluoroscopy guidance and one was repositioned just with ultrasound. No patient experienced a complication from the transfemoral snare technique such as femoral hematoma, hemorrhage or limb ischemia.

CONCLUSION

We describe three patients who successfully had dual-lumen cannulas repositioned without cessation of ECMO using a transfemoral "lasso" technique.

Echo-Guided Insertion of a Dual-Lumen Cannula for Venovenous Extracorporeal Membrane Oxygenation

We provide a step-by-step description of the insertion of a dual-lumen cannula, for venovenous extracorporeal membrane oxygenation support and how a close monitoring by combined transthoracic and transesophageal techniques ensures a safe procedure and can promptly detect complications.