Objectives & BackgroundResuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) aims to improve trauma survival by controlling torso haemorrhage. Selective Aortic Arch Perfusion (SAAP) is an experimental resuscitative technique that, in addition to controlling torso haemorrhage, allows infusion of oxygenated blood into the proximal aorta - theoretically providing coronary perfusion pressures adequate for return of spontaneous circulation (ROSC) in cardiac arrest (figure 1). Prolonged cardiac support can subsequently be achieved by converting the SAAP blood supply from exogenous to autologous via a central venous catheter–an extra-corporeal life support circuit (SAAP-ECLS).Hypotheses–1. Swine in haemorrhage-induced traumatic cardiac arrest that do not achieve a ROSC with initial therapy (REBOA), will have ROSC with more advanced therapy (SAAP). 2. Animals that do not achieve ROSC with REBOA and subsequent SAAP will achieve ROSC with SAAP-ECLS.Methods70–90 kg swine underwent a combination of non-compressible torso and arterial haemorrhage. Arrest was defined as a systolic blood pressure (SBP) <10 mm Hg, together with an inappropriate bradycardia. All animals initially received REBOA (inflation of zone 1 REBOA and four units of intravenous blood). Those that did not achieve ROSC (defined as SBP >50 mm Hg) subsequently received SAAP (800 ml/minute of intra-aortic oxygenated blood, up to 4000 ml). Animals that did not have a ROSC after SAAP received continuous SAAP-ECLS (at 800 ml/minute). The protocol end-point was 60 minutes from the start of the REBOA intervention. Data are descriptive, and presented as mean (+/−standard deviation) and number (percent).ResultsEight animals were included; weight 75.0 kg (+/−3.6); time from the start of the injury to onset of arrest was 9.9 minutes (+/−1.4). Two (25.0%) animals had a ROSC with REBOA, and out of the remaining six a further two (25.0%) had a ROSC with SAAP. The four remaining animals, that had not achieved ROSC with REBOA and subsequent SAAP, all had a ROSC with SAAP-ECLS (figure 2).ConclusionA step-wise approach of more complex endovascular intervention in haemorrhage-induced traumatic cardiac arrest may be an effective clinical paradigm – in this swine model all animals had short-term survival following escalating intervention: REBOA, followed by SAAP, followed SAAP-ECLS as required.Figure 1Figure 2

Objectives & BackgroundHaemorrhage is the leading cause of potentially survivable trauma death. Selective Aortic Arch Perfusion (SAAP) is an experimental resuscitative intervention that has the potential to improve trauma survival: a trans-femoral intra-aortic balloon controls torso haemorrhage, while the catheter's large central lumen allows oxygenated blood to be delivered to the proximal aorta–theoretically providing coronary perfusion pressures adequate for return of spontaneous circulation in cardiac arrest (figure 1).Hypothesis–In haemorrhage-induced traumatic cardiac arrest, SAAP with oxygenated blood will infer a short-term survival advantage over both closed chest compressions (CPR) with intravenous blood, and Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) with intravenous blood.Methods70–90 kg swine underwent a non-compressible torso haemorrhage (NCTH) and controlled arterial haemorrhage. Arrest was defined as a systolic blood pressure (SBP) <10 mm Hg, together with an inappropriate bradycardia. Animals were allocated to one of three groups: CPR with four units of intravenous blood, REBOA with four units of intravenous blood, and fresh whole blood SAAP (FWB-SAAP) with 1600 ml of oxygenated intra-aortic blood. Primary outcome was 60-minute ‘pre-hospital’ survival. Data are described as mean (+/− standard devation). Multi-group analyses were by ANOVA, and survival was analysed by Log-rank (Mantel-Cox) test.ResultsThere were ten animals per group, a total of 30 swine. Mean weight of 79.9 kg (+/−5.5) p=0.3. Mean time from the start of the injury to onset of arrest was 11.2 minutes (+/−1.9) p=0.2. Prior to intervention the mean SBP was 2.9 mm Hg (+/−3.2) p=0.7, and the mean heart rate was 41 bpm (+/−32) p=0.5.Primary outcome – FWB-SAAP demonstrated an 80% 60-minute ‘pre-hospital’ survival, compared to 10% with CPR, and 0% with REBOA, p<0.001 (figure 2).ConclusionIn this swine model of haemorrhage-induced traumatic cardiac arrest with NCTH, SAAP infers a short-term survival advantage over both conventional therapy (CPR), and over evolving therapy (REBOA). Of note, SAAP induced return of spontaneous circulation from cardiac electrical asystole.Figure 1Figure 2