Selective Aortic Arch Perfusion Research Articles

Selective aortic arch perfusion: a first-in-human observational cadaveric study

BackgroundSelective aortic arch perfusion (SAAP) is a novel endovascular technique that combines thoracic aortic occlusion with extracorporeal perfusion of the brain and heart. SAAP may have a role in both haemorrhagic shock and in cardiac arrest due to coronary ischaemia. Despite promising animal studies, no data is available that describes SAAP in humans. The primary aim of this study was to assess the feasibility of selective aortic arch perfusion in humans. The secondary aim of the study was to assess the feasibility of achieving direct coronary artery access via the SAAP catheter as a potential conduit for salvage percutaneous coronary intervention.MethodsUsing perfused human cadavers, a prototype SAAP catheter was inserted into the descending aorta under fluoroscopic guidance via a standard femoral percutaneous access device. The catheter balloon was inflated and the aortic arch perfused with radio-opaque contrast. The coronary arteries were cannulated through the SAAP catheter.ResultsThe procedure was conducted four times. During the first two trials the SAAP catheter was passed rapidly and without incident to the intended descending aortic landing zone and aortic arch perfusion was successfully delivered via the device. The SAAP catheter balloon failed on the third trial. On the fourth trial the left coronary system was cannulated using a 5Fr coronary guiding catheter through the central SAAP catheter lumen.ConclusionsFor the first time using a perfused cadaveric model we have demonstrated that a SAAP catheter can be easily and safely inserted and SAAP can be achieved using conventional endovascular techniques. The SAAP catheter allowed successful access to the proximal aorta and permitted retrograde perfusion of the coronary and cerebral circulation.

Renal cell carcinoma with intracardiac tumor thrombus extension: Radical surgery yields 2 years of postoperative survival in a single-center study over a period of 30 years.

Renal cell carcinoma (RCC) with tumor thrombus extension into the right atrium (level IV) is a rare life-threatening clinical condition that can only be managed by means of a combined urological and cardiac surgical approach. The early and late outcomes of this radical treatment were analyzed in a large single-institution series over a period of 30 years. In 37 patients with RCC and intracardiac tumor thrombus extension, nephrectomy was performed followed by the extraction of the intracaval and intracardiac tumor thrombus under direct visual control during deep hypothermic circulatory arrest (DHCA). Recently, in 13 patients, selective aortic arch perfusion (SAAP) was instituted during DHCA. In all patients, precise removal of the tumor thrombus was accomplished in a bloodless field. The mean duration of isolated DHCA was 15 ± 6min, and 31.5 ± 10.2min in the case of DHCA + SAAP, at a mean hypothermia of 22.7 ± 4°C. In-hospital mortality was 7.9% (3 patients). In Kaplan-Meier analysis, the estimated median survival was 26.4 months whereas the 5-year cancer-related survival rate was 51%. Despite its complexity, this extensive procedure can be performed safely with a generally uneventful postoperative course. The use of cardiopulmonary bypass with DHCA, with the advantage of SAAP, allows for a safe, precise, and complete extirpation of intracaval and intracardiac tumor mass. Late outcomes after radical surgical treatment in patients with RCC and tumor thrombus reaching up in the right atrium in our series justify this extensive procedure.

Whole Blood Selective Aortic Arch Perfusion for Exsanguination Cardiac Arrest: Assessing Myocardial Tolerance to the Duration of Cardiac Arrest.

Selective aortic arch perfusion (SAAP) is an endovascular technique that consists of aortic occlusion with perfusion of the coronary and cerebral circulation. It been shown to facilitate return of spontaneous circulation (ROSC) after exanguination cardiac arrest (ECA), but it is not known how long arrest may last before the myocardium can no longer be durably recovered. The aim of this study is to assess the myocardial tolerance to exsanguination cardiac arrest before successful ROSC with SAAP. Male adult swine (n = 24) were anesthetized, instrumented, and hemorrhaged to arrest. Animals were randomized into three groups: 5, 10, and 15 min of cardiac arrest before resuscitation with SAAP. Following ROSC, animals were observed for 60 min in a critical care environment. Primary outcomes were ROSC, and survival at 1-h post-ROSC. Shorter cardiac arrest time was associated with higher ROSC rate and better 1-h survival. ROSC was obtained for 100% (8/8) of the 5-min ECA group, 75% (6/8) of the 10-min group, 43% (3/7) of the 15-min group (P = 0.04). One-hour post-ROSC survival was 75%, 50%, and 14% in 5-, 10-, and 15-min groups, respectively (P = 0.02). One-hour survivors in the 5-min group required less norepinephrine (1.31 mg ± 0.83 mg) compared with 10-SAAP (0.76 mg ± 0.24 mg), P = 0.008. Whole blood SAAP can accomplish ROSC at high rates even after 10 min of unsupported cardiac arrest secondary to hemorrhage, with some viability beyond to 15 min. This is promising as a tool for ECA, but requires additional optimization and clinical trials.Animal Use Protocol, IACUC: 0919015.

Open chest selective aortic arch perfusion vs open cardiac massage as a means of perfusion during in exsanguination cardiac arrest: a comparison of coronary hemodynamics in swine.

To describe and compare the aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) generated during open chest selective aortic arch perfusion (OCSAAP) with those generated during open cardiac massage (OCM) in hypovolemic swine. Ten male Hanford swine utilized in a prior poly-trauma study were included in the study. Animals were rendered hypovolemic via a 30% volume bleed. Upon confirmation of death, animals underwent immediate clamshell thoracotomy and aortic cross-clamping followed by 5min of OCM. A catheter suitable for OCSAAP was then inserted into the aorta and animals underwent 1min of OCSAAP at a rate of 10mL/kg/min. Aortic and right atrial pressures were recorded continuously using solid-state blood pressure catheters. Representative 10-s intervals from each resuscitation method were extracted. Hemodynamic parameters including AoP-RAP gradients and CPPs were calculated and compared. At baseline, time from death to intervention was significantly shorter for OCM. However, mean CPPs and AoP-RAP gradients were significantly higher in animals undergoing OCSAAP. 98% of OCSAAP segments had a mean CPP > 15, compared to 35% of OCM intervals. While OCM had a significant negative correlation between time to intervention and maximum CPP, this correlation was not significant for OCSAAP. OCSAAP generates favorable and potentially time-resistant pressure gradients when compared to those generated by OCM. Further investigation of the technique of OCSAAP is warranted, as it may have potential utility as a therapy during resuscitative thoracotomy (RT).

O10 Myocardial tolerance to exsanguination and retrieval using whole blood-selective aortic arch perfusion

Abstract Introduction Exsanguination cardiac arrest is the leading preventable cause of death in trauma. Treatment modalities are limited, and prognosis remains dismal. Selective aortic arch perfusion (SAAP) is an emerging endovascular resuscitation technique consisting of aortic occlusion and perfusion of coronary and cerebral circulation with oxygenated resuscitation fluid. Translational research has demonstrated promising outcomes; however, little is known about the duration of cardiac arrest beyond which the myocardium cannot be resuscitated. The aims of this study are to assess the myocardial tolerance to exsanguination cardiac arrest before successful return of spontaneous circulation (ROSC) following resuscitation with SAAP, and 1-hour survival. Method 23 male adult swine were anaesthetised and instrumented. Controlled hemorrhage was performed until cardiac arrest defined by MAP <20 mmHg. Animals were randomized into 3 groups: 5, 10 and 15 minutes of cardiac arrest before resuscitation with SAAP. Following ROSC animals were observed for 60 minutes. Result Baseline characteristics were similar between groups (P > 0.05). ROSC was 100% (8/8) in the 5 min group, 75% (6/8) and 43% (3/7) in 10- and 15-min groups respectively (P = 0.042). 60 min survival was 75%, 50% and 14% in 5-, 10- and 15-min groups respectively (P = 0.015). 1-hour survivors in the 5 min group required less noradrenaline 23.6 (±7.4) compared to other animals 40.9 (±25.8), (P = 0.008). Conclusion Selective aortic arch perfusion is an effective resuscitative tool in eliciting ROSC in a swine model of exsanguination cardiac arrest lasting >5 min. Sustainable resuscitability using SAAP declines after 10 min of exsanguination cardiac arrest. Take-home Message SAAP is an emerging resuscitation technique with promising outcomes in exsanguination cardiac arrest and may be a segway to Extracorporeal life support. The time limit for resuscitability of the myocardium lies somewhere between 10 and 15 min after the start of exsanguination cardiac arrest.

Selective aortic arch perfusion versus open cardiac massage in exsanguination cardiac arrest: A comparison of coronary pressure dynamics in swine

AimTo evaluate the mean aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) observed during open cardiac massage (OCM) versus those obtained with selective aortic arch perfusion (SAAP) in post-mortem hypovolemic swine. MethodsPost-mortum, male swine, utilized in prior studies of hemorrhage, were included in the study. Animals were bled ∼25–50% of circulating volume prior to death. Animals either underwent clamshell thoracotomy and OCM immediately after death was confirmed (n = 6) or underwent SAAP within 5−15 min of death (n = 6). Aortic root and right atrial pressures were recorded continuously during each method of resuscitation using solid state blood pressure catheters. Representative five beat samples were extracted; short, similarly timed segments of SAAP were also extracted. Mean AoP-RAP gradient and CPPs were calculated and compared. ResultsMean AoP-RAP gradient and CPP were significantly higher in SAAP animals compared to OCM animals (mean ± SD; 29.1 ± 8.4 vs. 24.5 ± 5.0, p < 0.001; 28.9 ± 8.5 vs. 9.9 ± 6.0, p < 0.001). Mean CPP was not significantly different from mean AoP-RAP gradient in SAAP animals (p = 0.92); mean CPP was significantly lower than mean AoP-RAP gradient in OCM animals (p < 0.001). While 97% of SAAP segments had a CPP > 15 mmHg, only 17% of OCM segments had a CPP > 15 mmHg (p < 0.001). ConclusionSAAP appears to create a more favorable and efficient hemodynamic profile for obtaining ROSC when compared to OCM in this preclinical porcine study.

A technique for open chest selective aortic arch perfusion.

A technique for open chest selective aortic arch perfusion.

State-of-the-art methods for the treatment of severe hemorrhagic trauma: selective aortic arch perfusion and emergency preservation and resuscitation-what is next?

Trauma is a primary cause of death globally, with non‐compressible torso hemorrhage constituting an important part of “potentially survivable trauma death.” Resuscitative endovascular balloon occlusion of the aorta has become a popular alternative to aortic cross‐clamping under emergent thoracotomy for non‐compressible torso hemorrhage in recent years, however, it alone does not improve the survival rate of patients with severe shock or traumatic cardiac arrest from non‐compressible torso hemorrhage. Development of novel advanced maneuvers is essential to improve these patients’ survival, and research on promising methods such as selective aortic arch perfusion and emergency preservation and resuscitation is ongoing. This review aimed to provide physicians in charge of severe trauma cases with a broad understanding of these novel therapeutic approaches to manage patients with severe hemorrhagic trauma, which may allow them to develop lifesaving strategies for exsanguinating trauma patients. Although there are still hurdles to overcome before their clinical application, promising research on these novel strategies is in progress, and ongoing development of synthetic red blood cells and techniques that reduce ischemia‐reperfusion injury may further maximize their effects. Both continuous proof‐of‐concept studies and translational clinical evaluations are necessary to clinically apply these hemostasis approaches to trauma patients.

The Effect of Chest Compression Location and Aortic Perfusion in a Traumatic Arrest Model

BackgroundRecent evidence demonstrates that closed chest compressions directly over the left ventricle (LV) in a traumatic cardiac arrest (TCA) model improve hemodynamics and return of spontaneous circulation (ROSC) when compared to traditional compressions. Selective aortic arch perfusion (SAAP) also improves hemodynamics and controls hemorrhage in TCA. We hypothesized that chest compressions located over the LV would result in improved hemodynamics and ROSC in a swine model of TCA using SAAP. Materials and methodsTransthoracic echo was used to mark the location of the aortic root (Traditional location) and the center of the LV on animals (n = 24), which were randomized to receive chest compressions in one of the two locations. After hemorrhage, ventricular fibrillation (VF) was induced to simulate TCA. After a period of 10 min of VF, basic life support (BLS) with mechanical CPR was initiated and performed for 10 min, followed by advanced life support (ALS) for an additional 10 min. SAAP balloons were inflated at min 6 of BLS. Hemodynamic variables were averaged over the final 2 min of the BLS and ALS periods. Survival was compared between this SAAP cohort and a control group without SAAP (No-SAAP) (n = 26). ResultsThere was no significant difference in ROSC between the two SAAP groups (P = 0.67). There was no ROSC difference between SAAP and No-SAAP (P = 0.74). ConclusionsThere was no difference in ROSC between LV and Traditional compressions when SAAP was used in this swine model of TCA. SAAP did not confer a survival benefit compared to historical controls.

State-of-the-Art Review-Endovascular Resuscitation.

The emerging concept of endovascular resuscitation applies catheter-based techniques in the management of patients in shock to manipulate physiology, optimize hemodynamics, and bridge to definitive care. These interventions hope to address an unmet need in the care of severely injured patients, or those with refractory non-traumatic cardiac arrest, who were previously deemed non-survivable. These evolving techniques include Resuscitative Endovascular Balloon Occlusion of Aorta, Selective Aortic Arch Perfusion, and Extracorporeal Membrane Oxygenation and there is a growing literature base behind them. This review presents the up-to-date techniques and interventions, along with their application, evidence base, and controversy within the new era of endovascular resuscitation.

Development of a Selective Aortic Arch Perfusion System in a Porcine Model of Exsanguination Cardiac Arrest.

Hemorrhage constitutes the majority of potentially preventable deaths from trauma. There is growing interest in endovascular resuscitation techniques such as selective aortic arch perfusion (SAAP) for patients in cardiac arrest. This involves active perfusion of the coronary circulation via a thoracic aortic balloon catheter and is approaching clinical application. However, the technique is complex and requires refinement in animal models before human use can be considered. This paper describes a large animal model of exsanguination cardiac arrest treated with a bespoke SAAP system. Swine were anesthetized, instrumented and a splenectomy was performed before a controlled, logarithmic exsanguination was initiated. Animals were heparinized and the shed blood collected in a reservoir. Once cardiac arrest was observed, the blood was pumped through an extra-corporeal circuit into an oxygenator and then delivered through a 10 Fr balloon catheter placed in the thoracic aorta. This resulted in the return of a spontaneous circulation (ROSC) as demonstrated by ECG and aortic root pressure waveform. This model and accompanying SAAP system allow for standardized and reproducible recovery from exsanguination cardiac arrest.

Emerging hemorrhage control and resuscitation strategies in trauma: Endovascular to extracorporeal.

This article reviews four emerging endovascular hemorrhage control and extracorporeal perfusion techniques for management of trauma patients with profound hemorrhagic shock including hemorrhage-induced traumatic cardiac arrest: resuscitative endovascular balloon occlusion of the aorta, selective aortic arch perfusion, extracorporeal life support, and emergency preservation and resuscitation. The preclinical and clinical studies underpinning each of these techniques are summarized. We also present an integrated conceptual framework for how these emerging technologies may be used in the future care of trauma patients in both resource-rich and austere environments.

Abstract 253: The Efficacy of Left Ventricular versus Traditional Chest Compressions During Selective Aortic Arch Perfusion to Treat Traumatic Cardiopulmonary Arrest in a Swine Model

Introduction: Recent evidence has demonstrated that closed chest compressions (CC) directly over the left ventricle (LV) during traumatic cardiopulmonary arrest (TCPA) improve hemodynamics and return of spontaneous circulation (ROSC) when compared to traditional chest compressions. Selective Aortic Arch Perfusion (SAAP) is also able to improve hemodynamics as well as control hemorrhage during TCPA. Hypothesis: We hypothesized that LV compressions would increase ROSC when compared to traditional compressions in an animal model of TCPA where SAAP was being used. We also compared LV and Traditional compressions with SAAP to historical controls that received compressions without SAAP. Methods: Transthoracic echo was used to mark the location of the aortic root and the center of the left ventricle on animals (n=24, 12 in each arm) which were randomized to receive chest compressions in one of the two locations. One third of each animal’s blood volume was removed and ventricular fibrillation (VF) was induced to simulate traumatic cardiac arrest. After a period of ten minutes of VF, basic life support (BLS) with mechanical CPR was initiated and performed for ten minutes followed by advanced life support (ALS) and blood transfusion for an additional ten minutes. The SAAP balloon was inflated at minute 6 of BLS. Hemodynamic variables were averaged every two minutes. The same model was used for historical controls (n=26, 13 in each arm) without the use of SAAP, so comparisons were treated as a single study with a factorial design. Results: There were no differences in hemodynamic variables, ROSC (p=0.67) or survival (p=0.64) between SAAP groups. However, when the LV animals were compared to historic controls without SAAP, LV animals had higher ROSC (p=0.02) and survival rates (p=0.04) than Traditional animals. Conclusions: SAAP does not appear to show a synergistic effect with LV compressions, however, SAAP combined with LV compressions improves ROSC and survival when compared to Traditional compressions in our swine model of TCPA. More investigation into SAAP and compression position should be studied to improve treatment of TCPA.

Selective aortic arch perfusion with fresh whole blood or HBOC-201 reverses hemorrhage-induced traumatic cardiac arrest in a lethal model of noncompressible torso hemorrhage.

Hemorrhage-induced traumatic cardiac arrest (HiTCA) has a dismal survival rate. Previous studies demonstrated selective aortic arch perfusion (SAAP) with fresh whole blood (FWB) improved the rate of return of spontaneous circulation (ROSC) after HiTCA, compared with resuscitative endovascular balloon occlusion of the aorta and cardiopulmonary resuscitation (CPR). Hemoglobin-based oxygen carriers, such as hemoglobin-based oxygen carrier (HBOC)-201, may alleviate the logistical constraints of using FWB in a prehospital setting. It is unknown whether SAAP with HBOC-201 is equivalent in efficacy to FWB, whether conversion from SAAP to extracorporeal life support (ECLS) is feasible, and whether physiologic derangement post-SAAP therapy is reversible. Twenty-six swine (79 ± 4 kg) were anesthetized and underwent HiTCA which was induced via liver injury and controlled hemorrhage. Following arrest, swine were randomly allocated to resuscitation using SAAP with FWB (n = 12) or HBOC-201 (n = 14). After SAAP was initiated, animals were monitored for a 20-minute prehospital period prior to a 40-minute damage control surgery and resuscitation phase, followed by 260 minutes of critical care. Primary outcomes included rate of ROSC, survival, conversion to ECLS, and correction of physiology. Baseline physiologic measurements were similar between groups. ROSC was achieved in 100% of the FWB animals and 86% of the HBOC-201 animals (p = 0.483). Survival (t = 320 minutes) was 92% (11/12) in the FWB group and 67% (8/12) in the HBOC-201 group (p = 0.120). Conversion to ECLS was successful in 100% of both groups. Lactate peaked at 80 minutes in both groups, and significantly improved by the end of the experiment in the HBOC-201 group (p = 0.001) but not in the FWB group (p = 0.104). There was no significant difference in peak or end lactate between groups. Selective aortic arch perfusion is effective in eliciting ROSC after HiTCA in a swine model, using either FWB or HBOC-201. Transition from SAAP to ECLS after definitive hemorrhage control is feasible, resulting in high overall survival and improvement in lactic acidosis over the study period.

Novel Interventions for Non-Compressible Torso Hemorrhage: Secondary Considerations in Consequences of Aortic Occlusion

Non-compressible torso hemorrhage in trauma remains a leading cause of death in austere environments. Advancements for treatment include resuscitative endovascular balloon occlusion of the aorta (REBOA), selective aortic arch perfusion (SAAP), and external compression approaches (junctional tourniquets and abdominal aortic tourniquets), which have provided several promising avenues. However, the application of these devices carries the risk of distal ischemia and the consequences associated with reperfusion injury. This review aims to look at these novel interventions and the physiologic burden associated with them. Following a review of these new advents, we will evaluate the possible solutions to reverse the physiologic penalties.

A comparison of Selective Aortic Arch Perfusion and Resuscitative Endovascular Balloon Occlusion of the Aorta for the management of hemorrhage-induced traumatic cardiac arrest: A translational model in large swine.

BackgroundSurvival rates remain low after hemorrhage-induced traumatic cardiac arrest (TCA). Noncompressible torso hemorrhage (NCTH) is a major cause of potentially survivable trauma death. Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) at the thoracic aorta (Zone 1) can limit subdiaphragmatic blood loss and allow for IV fluid resuscitation when intrinsic cardiac activity is still present. Selective Aortic Arch Perfusion (SAAP) combines thoracic aortic balloon hemorrhage control with intra-aortic oxygenated perfusion to achieve return of spontaneous circulation (ROSC) when cardiac arrest has occurred.Methods and findingsMale Yorkshire Landrace cross swine (80.0 ± 6.0 kg) underwent anesthesia, instrumentation for monitoring, and splenectomy. TCA was induced by laparoscopic liver lobe resection combined with arterial catheter blood withdrawal to achieve a sustained systolic blood pressure <10 mmHg, cardiac arrest. After 3 min of arrest, swine were allocated to one of three interventions: (1) REBOA plus 4 units of IV fresh whole blood (FWB), (2) SAAP with oxygenated lactated Ringer’s (LR), 1,600 mL/2 min, or (3) SAAP with oxygenated FWB 1,600 mL/2 min. Primary endpoint was survival to the end of 60 min of resuscitation, a simulated prehospital phase. Thirty animals were allocated to 3 groups (10 per group)—5 protocol exclusions resulted in a total of 35 animals being used. Baseline measurements and time to cardiac arrest were not different amongst groups. ROSC was achieved in 0/10 (0%, 95% CI 0.00–30.9) REBOA, 6/10 (60%, 95% CI 26.2–87.8) SAAP-LR and 10/10 (100%, 95% CI 69.2–100.0) SAAP-FWB animals, p < 0.001. Survival to end of simulated 60-minute prehospital resuscitation was 0/10 (0%, 95% CI 0.00–30.9) for REBOA, 1/10 (10%, 95% CI 0.25–44.5) for SAAP-LR and 9/10 (90%, 95% CI 55.5–99.7) for SAAP-FWB, p < 0.001. Total FWB infusion volume was similar for REBOA (2,452 ± 0 mL) and SAAP-FWB (2,250 ± 594 mL). This study was undertaken in laboratory conditions, and as such may have practical limitations when applied clinically. Cardiac arrest in this study was defined by intra-aortic pressure monitoring that is not feasible in clinical practice, and as such limits the generalizability of findings. Clinical trials are needed to determine if the beneficial effects of SAAP-FWB observed in this laboratory study will translate into improved survival in clinical practice.ConclusionsSAAP conferred a superior short-term survival over REBOA in this large animal model of hemorrhage-induced traumatic cardiac arrest with NCTH. SAAP using an oxygen-carrying perfusate was more effective in this study than non-oxygen carrying solutions in TCA. SAAP can effect ROSC from hemorrhage-induced electrocardiographic asystole in large swine.

A comparison of Selective Aortic Arch Perfusion and Resuscitative Endovascular Balloon Occlusion of the Aorta for the management of hemorrhage-induced traumatic cardiac arrest: A translational model in large swine

A comparison of Selective Aortic Arch Perfusion and Resuscitative Endovascular Balloon Occlusion of the Aorta for the management of hemorrhage-induced traumatic cardiac arrest: A translational model in large swine

A DESCRIPTIVE PARADIGM OF ESCALATING ENDOVASCULAR INTERVENTION FOR THE MANAGEMENT OF TRAUMATIC CARDIAC ARREST IN A SWINE MODEL OF NON-COMPRESSIBLE TORSO HAEMORRHAGE

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,...

SELECTIVE AORTIC ARCH PERFUSION FOR THE REVERSAL OF HAEMORRHAGE-INDUCED TRAUMATIC CARDIAC ARREST IN A SWINE MODEL OF NON-COMPRESSIBLE TORSO HAEMORRHAGE

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:...

Aortic Hemostasis and Resuscitation: Preliminary Experiments Using Selective Aortic Arch Perfusion With Oxygenated Blood and Intra-aortic Calcium Coadministration in a Model of Hemorrhage-induced Traumatic Cardiac Arrest.

Selective aortic arch perfusion (SAAP) uses a thoracic aortic balloon occlusion catheter for heart and brain perfusion in cardiac arrest to achieve return of spontaneous circulation (ROSC). SAAP with oxygenated stored blood was studied in a model of hemorrhage-induced cardiac arrest. The study hypothesis was that intra-aortic calcium coadministration would be required to maintain normal aortic arch blood ionized calcium during SAAP and to achieve ROSC. Twelve anesthetized, domestic swine underwent severe hemorrhage and liver injury resulting in cardiac arrest. Whole blood and packed red blood cells (RBCs) stored in citrate anticoagulant served as perfusates for SAAP. Experiments were performed with four combinations of SAAP with oxygenated stored blood and intra-aortic calcium gluconate infusion: 1) whole blood without calcium, 2) whole blood with calcium, 3) lactated Ringers-diluted packed RBCs with calcium, and 4) normal saline-diluted packed RBCs with calcium. Aortic arch blood ionized calcium was monitored. Occurrence of ventricular dysrhythmias, success rate for ROSC, and the need for simultaneous intra-aortic calcium infusion were assessed. Selective aortic arch perfusion using whole blood without intra-aortic calcium (n = 2) resulted in severe aortic blood ionized hypocalcemia, refractory ventricular fibrillation, and no ROSC. SAAP using whole blood with intra-aortic calcium (n = 4) resulted in ROSC in all four animals. Two of four developed ventricular fibrillation that was successfully defibrillated. SAAP using packed RBCs with intra-aortic calcium resulted in ROSC in all six animals, but the intra-aortic calcium dose needed to maintain normal aortic arch blood ionized calcium levels was one-third of that needed for SAAP with whole blood. Dilution of packed RBCs with lactated Ringers (n = 2) resulted in formation of small clots in the perfusion circuit which were not seen with packed RBCs diluted with normal saline (n = 4). Selective aortic arch perfusion with stored whole blood or packed RBCs requires simultaneous intra-aortic calcium infusion to overcome citrate anticoagulant calcium binding, avoid refractory ventricular fibrillation, and allow for ROSC.