REBOA – The What, Why, How and When – Dr Jamie Moran, Retrieval Registrar, Sydney HEMS

This week Jamie Moran presented a summary of Resuscitative Endovascular Balloon Occlusion of the Aorta, or REBOA, based on his expereince with London HEMS.

The talk focused on zone III REBOA in the pre-hospital setting; the equipment needed to perform it, insertion technique and the ongoing care in the Emergency Department once the patient reaches hospital. Clinical examples were given to highlight some of the issues relating to patient selection and challenges of the technique in the field.

What

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is an interventional technique, which may save lives in patients dying from catastrophic, non-compressible haemorrhage from severe pelvic trauma or junctional vascular injury. It involves placement of an endovascular balloon in the aorta to control haemorrhage and to augment afterload in traumatic arrest and haemorrhagic shock states

London’s Air Ambulance has used it in the pre-hospital setting since 2014 and within the Emergency Department at The Royal London Hospital. The numbers of cases so far are small.

Why

Experience from the Royal London Hospital and London’s Air Ambulance shows that non-compressible torso haemorrhage is the leading cause of preventable trauma deaths. Severe pelvic fractures and torso vascular injuries are two important sources of this bleeding and contribute up to one third of all trauma deaths seen by the service. Trauma systems have optimized access to definitive haemorrhage control but many patients die from blood loss before this can be achieved.

REBOA may save lives in this patient group by reducing blood loss in the prehospital and resuscitation room phase, which buys time to get the patient to either the operating room or interventional radiology suite. Experimental evidence, mainly from large animal models, suggests that REBOA may increase myocardial and cerebral perfusion in the shocked state, reduce distal blood loss and promote clot formation. REBOA is likely to cause less physiological stress as a means of haemorrhage control than thoracotomy and aortic cross clamping.

How

Via a simple Seldinger technique – that is; needle puncture, guide wire insertion, over-the-wire balloon catheter. It is inserted under ultrasound guidance via the common femoral artery.

The REBOA catheter is inserted into zone three (based on proven measurements in adults) of the aorta – a region between the most caudal renal artery and the aortic bifurcation.

When

In any adult patient believed to be bleeding to death from a severe pelvic injury or junctional injury, after/during a simultaneous treatment bundle to stabilize the patient and promote blood clot formation. This includes blood transfusion, pelvic splintage, tranexamic acid, intubation and IPPV and addressing of other concurrent life threatening injuries.

By definition, these patients are bleeding to death and the massive transfusion pathway is activated in the receiving trauma unit in a timely manner so that blood products are available as soon as the patient arrives in the hospital or on the helipad. In addition, a specific REBOA activation call is made. This brings the additional expertise of a specifically trained REBOA operator, interventional radiologist and orthopaedic surgeon (in the case of pelvic injury) to the usual trauma response for these patients.

The Future

The UK REBOA trial is a Bayesian group sequential Randomised Controlled Trial (RCT) which will evaluate the use of REBOA in addition to standard treatment alone across the UK. The primary outcome measure is 90-day mortality in each group.

The study will also look into Zone 1 REBOA (insertion of REBOA balloon into the region of the aorta from the left subclavian artery to the coeliac trunk) as a means of controlling more proximal blood loss from, for example, blunt liver and splenic injuries.