• The major rate limiting step with REBOA is accurate and expedient common femoral artery (CFA) access. Ultrasound guided access is the preferred method for CFA access; however, in early experience, up to 50% of cases required open exposure. Smaller access sheaths are associated with improved outcomes.^31-34 As early CFA access has become more routine in select trauma centers, the need for open CFA exposure has decreased to below 10%.³⁵
• Literature for REBOA are mixed; some demonstrate a survival benefit^20-21 while others suggest REBOA may actually worsen mortality.^22-23 The advent of the wireless ER-REBOA™ and COBRA-OS®, combined with a better understanding of REBOA indications led to recent studies demonstrating the non-inferiority of REBOA. In patients that do not require cardiopulmonary resuscitation (CPR), REBOA has now shown a survival benefit.^24-27,15 In 2018, a prospective analysis documented that REBOA improved survival beyond the emergency department and to hospital discharge compared to ERT when applied prior to traumatic cardiac arrest in patients with hemorrhagic shock.¹⁵
• A primary limitation of first generation REBOA (ER-REBOA-PLUS™ and COBRA-OS®) is the short Zone 1 aortic occlusion time prior to the increasing risk of distal ischemia (See page 10 for an Illustration of the zones of the aorta). The AAST AORTA database revealed that 63% of REBOA cases exceeded 30 minutes in Zone 1 and the median occlusion time was 40 minutes.¹ Partial REBOA (pREBOA) addresses some of these limitations by allowing a small volume of blood to continuously flow past the balloon and perfuse distal tissues and organs while mitigating ongoing hemorrhage. The patient selection and indication guidelines for pREBOA are largely based on consensus guidelines from select civilian trauma centers.^36,75,77
• In a preclinical study done by Polcz et al. 2021, Targeted Regional Optimization (TRO), a partial REBOA strategy, enhanced blood flow to vital organs like the heart and brain while maintaining a minimum level of perfusion to the lower body and limbs. Furthermore, partial occlusion facilitated faster renal function recovery. Finally, a linear correlation between distal Mean Arterial Pressure (MAP) and distal aortic flow rate was observed, providing a valuable clinical metric for informed decision-making.³⁷
• Third generation pREBOA-PRO™ devices allow prolonged partial aortic occlusion in Zone 1 for at least 2 hours without increase in ischemic complications.³⁸ In animal and civilian studies, it has been shown that Zone 1 partial occlusion can increase to 4 hours with treatable distal ischemic changes.³⁹ In civilian trauma centers utilizing this technique, partial REBOA use has reduced cardiac arrest and blood product usage, and increased use of angioembolization with reduced distal ischemia.⁴⁰
• Critical hemorrhage models in swine demonstrate that pREBOA can extend aortic occlusion time to at least 2 hours with continuous controlled pulsatile distal pressure of at least 20 mmHg systolic blood pressure (SBP) without increased distal ischemic complications.³⁹ Clinical data in civilian trauma centers and early military data from the Ukraine War^41-42 demonstrate similar results. Partial REBOA with an extension of occlusion time of up to 4 hours without compromising survival or worsening ischemic injury may be feasible.