ECMO cannulation by non-surgeons is safe

Abstract

The extracorporeal membrane oxygenation (ECMO) cannulae can be safely inserted into the jugular and femoral regions using a percutaneous dilation technique or by open surgical cannulation. Percutaneous dilation that avoids skin cutting can achieve a tight seal between skin, vessels and cannulae. This avoids bleeding associated with surgical dissection and limits tissue damage. Surgical dissection is also associated with additional risks of wound breakdown and seroma formation in critically ill patients (particularly those requiring long-term immunosuppression). Non-surgical cannulation also offers the advantage of avoiding the need for additional patient transfer to the operating theatre. Moreover, it has been safely performed in a variety of settings, without affecting surgical workflow. Percutaneous cannulation can be performed by a broad range of hospital medical specialists and obviates the need for surgical attendance in time critical settings. Non-surgical cannulation for both veno-arterial and veno-venous ECMO is well established in many experienced ECMO centres and is an entrenched practice.1,2 Risks associated with “blind” percutaneous cannulation can be greatly reduced with the use of real-time vascular ultrasound, which is now commonplace in modern intensive care and anaesthetic settings. In conjunction with real-time echocardiography, complete visualisation of guide-wire and cannula insertion is possible. Other radiological support can also increase the safety of percutaneous insertion. Technical training and skill acquisition is required for safe percutaneous cannulation with ultrasound. It should not be performed by those without training and credentialing. Direct visualisation of the vessel does not remove the risks of serious complications from ECMO cannulation. Utility of ultrasound in ECMO cannulation include: • Anatomical assessment of the target vessel and cannulation planning. This includes the detection of intravascular thrombosis prior to cannulation as well as the detection of peripheral vascular disease; • Real-time needle localisation facilitates accurate needle insertion, which reduces the risks of inadvertent sapheno-femoral junction venous cannulation and inadvertent profunda femoris artery injury (femoral artery cannulation), and ultrasound assessment of guidewire placement allows confirmation of position prior to dilation; • Optimal siting of venous cannulae tips; • Detection and avoidance of cardiac abnormalities – particularly involving the right atrium such as Chiari network or prominent, remnant eustachian and thebesian valves which can have an impact on correct siting of access cannulae. Surgical cannulation is required for subclavian arterial return ECMO configurations and central ECMO configurations. Central cannulation should not be used unless adequate support cannot be achieved by peripheral cannulation due to the very high rates of bleeding and serious complications. Surgical repair is also standardly required for vascular repair following the removal of an arterial ECMO cannula. Ideally patients should have access to timely ECMO support and should have their configuration modified to best meet their needs when required. Thus, access to timely non-surgical cannulation and recourse to surgical cannulation for specific needs is the optimal model of care.