The Pre-brief
We’ve all heard of the potential benefit and immense controversy associated with resuscitative endovascular balloon occlusion of the aorta (REBOA). Whether you use it or not, certainly I feel in select cases in the right system, it is a useful tool in the hemorrhage resuscitation box. One of the biggest challenges with REBOA devices has been the necessary size of the access sheath placed in the common femoral artery (CFA). This started with devices requiring 12-14 French (Fr) sheaths, and the latest FDA-approved device in the US goes through a 7-French sheath. This innovation has made immense improvements in the risk of vessel injury.
So, not to sound too crass, but size does matter! Now, our Canadian friends seem to have improved on this even further.
The News
A company in Canada has developed a new 4-Fr device that just received the equivalent of FDA approval in Canada. It’s always essential to have a cool name, and this one is called the COBRA-OS (Control of Bleeding, Resuscitation, Arterial Occlusion System).
This may be a real game changer, as this small size that allows much less traumatic access to the CFA and may make it more feasible to use in patients who may have smaller vessels (either as their anatomic baseline or due to vasoconstriction from hemorrhagic shock). Importantly this may open up the device to be used, in appropriate circumstances, in pediatric patients.
Importantly, however, this does not solve the significant challenge of actually accessing the CFA in the first place in someone trying to die on you – this remains the rate-limiting step for this procedure.
The COBRA-OS is pictured here. Like the 7-Fr ER-REBOA catheter, it is a guidewire-free device, meaning the catheter is inserted directly through the vascular access sheath introducer without the need for inserting a guidewire. See the full video of inserting the device here.
Has It Been Tested?
Yes – the clinicians who developed this device have recently published a human study to show device feasibility, published in Trauma Surgery Acute Care Open.
The study authors used patients who were deemed organ donors after a declaration of neurologic death in order to test feasibility. This has been a method utilized in prior studies, especially when a procedure is dependent on specific clinical situations to be effectively trialed.
4-Fr sheaths were placed in both CFAs during the organ retrieval phase of these patients’ care. The REBOA catheter was inserted on one side in both the Zone 1 (descending thoracic aorta) and Zone 3 (aortic bifurcation) positions, and arterial pressure below the occlusion was measured through the sheath placed on the left side (essentially acting as a femoral arterial line).
The study enrolled seven patients. The highlights of their findings included:
- 71% male and 29% female
- Mean age was 46.6 years
- Mean time to placement of the 4-Fr access sheaths was 47.7 seconds (range 28-66s)
- Mean time from skin puncture to Zone 1 occlusion was 70.1 seconds (58-105s)
- Mean balloon volumes were 15mL for Zone 1, and 9mL for Zone 3
- When the aorta was visually inspected after sheath removal, there was no evidence of injury from device insertion
The Debrief
As the evidence evolves for REBOA, the technology must also. This device’s arrival is exciting news for those whose systems already support REBOA use and may allow some others who have been on the fence to consider implementing it.
