Cardiopulmonary Bypass Circuit Research Articles

The effect of air-free administration of intravenous drugs on microemboli during cardiopulmonary bypass.

During cardiopulmonary bypass (CPB), gaseous microemboli (GME) that originate from the extracorporeal circuit are released into the arterial blood stream of the patient. Gaseous microemboli may contribute to adverse outcome after cardiac surgery with CPB. Possibly, air may be collected in the right atrium during induction of anesthesia and released during CPB start. The aim of this study was to assess if the GME load entering the venous line of the CPB circuit could be reduced by training of anesthesia personal in avoiding air introduction during administration of intravenous medication. In 94 patients undergoing coronary artery bypass grafting with CPB, GME number and volume were measured intraoperatively with a bubble counter (BCC300). The quantity and the relationship between GME number and volume in the venous and arterial line were determined in 2 periods before and after education of the anesthesiologists and nurses. In the venous line no significant differences were observed between numbers and volumes of GME between groups. Comparing patients with low versus high GME load, showed significantly more patients from the intervention group in the low GME-load group, namely 29 versus 18. Administration of medication by anesthesia was confirmed as a clear cause of GME/air-introduction into the venous circulation. Scavenging properties of the CPB circuit including the oxygenator showed a 99.9% reduction of GME. A wide spread of GME generation during perfusion was present with no difference in generation of GME between groups. Lower GME load observed in patients (intervention group) and examples of air introduction during drug administration suggest that air introduced by anesthesia contributes to the GME load during CPB. Scavenging properties of the CPB circuit contribute very much to patient safety regarding reduction of venous air. Awareness and education create the possibilities for further reduction of GME during cardiopulmonary bypass.

Characterization and comparative evaluation of polysulfone and polypropylene hollow fiber membranes for blood oxygenators

AbstractBlood oxygenators are used to saturate oxygen levels and remove carbon dioxide from the body during cardiopulmonary bypass. Although the natural lung is hydrophilic, commercially used oxygenator materials are hydrophobic. Surface hydrophobicity weakens blood compatibility, as long‐term contact with the blood environment may lead to different degrees of blood activity. Polysulfone may be considered an alternative hydrophilic material in the design of oxygenators. Therefore, it may be directed toward developing hydrophilic membranes. This study aims to investigate the feasibility of achieving blood gas transfer with a polysulfone‐based microporous hollow fiber membrane and compare it with the commercially available polypropylene membranes. Structural differences in the membrane morphology, surface hydrophilicity, tortuosity, mass transfer rate, and material properties under different operation conditions of temperature and flow rates are reported. The polysulfone membrane has a water contact angle of 81.3°, whereas a commercial polypropylene membrane is 94.5°. The mass transfer resistances (s/m) for the polysulfone and polypropylene membranes are calculated to be 4.8 × 104 and 1.5 × 104 at 25°C, respectively. The module made of polysulfone was placed in the cardiopulmonary bypass circuit in parallel with the commercial oxygenator, and pH, pO2, pCO2 levels, and metabolic activity were measured in blood samples.

The Number of Microbubbles Generated During Cardiopulmonary Bypass Can Be Estimated Using Machine Learning From Suction Flow Rate, Venous Reservoir Level, Perfusion Flow Rate, Hematocrit Level, and Blood Temperature.

Microbubbles (MBs) are known to occur within the circuits of cardiopulmonary bypass (CPB) systems, and higher-order dysfunction after cardiac surgery may be caused by MBs as well as atheroma dispersal associated with cannula insertion. As complete MB elimination is not possible, monitoring MB count rates is critical. We propose an online detection system with a neural network-based model to estimate MB count rate using five parameters: suction flow rate, venous reservoir level, perfusion flow rate, hematocrit level, and blood temperature. Perfusion experiments were performed using an actual CPB circuit, and MB count rates were measured using the five varying parameters. Bland-Altman analysis indicated a high estimation accuracy (R2 > 0.95, p < 0.001) with no significant systematic error. In clinical practice, although the inclusion of clinical procedures slightly decreased the estimation accuracy, a high coefficient of determination for 30 clinical cases (R2 = 0.8576) was achieved between measured and estimated MB count rates. Our results highlight the potential of this system to improve patient outcomes and reduce MB-associated complication risk.

Breaches in Infection Prevention and Controls Discovered During an Outbreak Investigation of Two Unlinked Cases of Pseudomonas aeruginosa Bloodstream Infections in a Cardiovascular Thoracic Surgery Unit

Two patients with Pseudomonas aeruginosa bloodstream infections were diagnosed a week apart in a cardiovascular thoracic (CVT) surgery unit where there had been no cases of P. aeruginosa infections in the preceding 6 months. An outbreak investigation was conducted. Medical records were reviewed to identify potential common exposure in both patients. Outbreak investigation procedures included cultures of intravenous infusions and various solutions in the operating theatre and the general CVT surgery unit, the intensive care unit and the intermediate care unit, and monitoring compliance with the central line associated bloodstream infection prevention bundle. Both the blood cultures of the two patients as well as the liquid soap used for hand washing in the unit grew P. aeruginosa. However, there were three clonalities of isolates, the first from patient A, the second from patient B, and the third from the liquid soap. Other intravenous infusions and various solutions, i.e., normal saline solution, lactate ringer solutions, solutions for cardiopulmonary bypass circuits, and skin antisepsis, did not grow potential pathogens. In conclusion, although these were unlinked cases, investigation of the cases uncovered breaches in infection control practices and provided an opportunity to improve the infection control strategies in our institution.. KEYWORDS P. aeruginosa, bloodstream infection, outbreak, outbreak investigation, infection control

Temporary Right Ventricular Support Using the Existing Bypass Circuit During LVAD Implantation

BackgroundRight-sided heart failure after left ventricular assist device (LVAD) implantation carries high morbidity. We sought to develop a technique for expedient short-term right ventricular (RV) support with the cardiopulmonary bypass (CPB) circuit already in use during the LVAD implantation procedure. MethodsPatients at high risk for RV failure during LVAD implantation were supported by a modified CPB circuit. A standard CPB circuit was modified to include a series of 4 wye (Y) bridge connections, allowing the ability to exclude the venous reservoir and oxygenator and to flow venous blood or arterialized blood in the same CPB outflow line. ResultsFrom 2019 to 2022 at a single institution, 6 patients were identified as high risk for early RV failure. Preoperative mean clinical values included central venous pressure of 16.3 ± 3.2 mm Hg, pulmonary capillary wedge pressure of 26.7 ± 3.2 mm Hg, tricuspid annular plane systolic excursion of 1.2 ± 0.23 cm, RV stroke work index of 311.7 ± 32.5, and central venous pressure/pulmonary capillary wedge pressure of 0.61 ± 0.10. All 6 patients were successfully weaned from CPB to LVAD support without the need for RV support at the conclusion of the implantation procedure. ConclusionsWe describe a configuration that supports the right ventricle during the critical period after CPB when it is at high risk of failure while the patient is being resuscitated with transfusions and volume. This technique provides flexibility in the management of complex, critically ill patients with RV failure, increasing the possibility of intraoperative RV recovery and successful separation from CPB during LVAD implantation.

Heparin consumption and inflammatory response according to the coating of cardiopulmonary bypass circuits in cardiac surgery: A retrospective analysis.

There are several types of surface treatments (coatings) aimed at improving the biocompatibility of cardiopulmonary bypass (CPB) circuit. Some coatings appear to require higher doses of heparin to maintain anticoagulation goals, and some of them might induce postoperative coagulopathy. In this study, we compared the amount of heparin required, postoperative bleeding, and inflammatory response according to three types of coatings. We retrospectively included 300 consecutive adult patients who underwent cardiac surgery with CPB and received one of three coatings (Phisio®, Trillium®, and Xcoating™). Our primary objective was to compare, according to coating, the amount of heparin required to maintain an ACT > 400s during CPB. Our secondary objectives were to compare postoperative bleeding for 48h and CRP rate. Baseline characteristics were comparable between groups except for age and preoperative CRP. We did not find a significant difference between the 3 coatings regarding the amount of heparin reinjected. However, we found less postoperative bleeding with the Xcoating™ circuit compared to the Phisio® circuit (-149mL [-289; -26.5]; p = 0.02) and a lower elevation of CRP with the Phisio® circuit (2.8times higher than preoperative CRP) compared to Trillium® (4.9times higher) and Xcoating™ (6.4times higher); p < 10-3. The choice of coating did not influence the amount of heparin required during CPB; however, the post-CPB inflammatory syndrome may be impacted by this choice.

Performance Evaluation of Geometrically Different Pediatric Arterial Cannulae in a Pediatric Cardiopulmonary Bypass Model.

To define a reference chart comparing pressure drop vs. flow generated by a set of arterial cannulae currently utilized in cardiopulmonary bypass conditions in pediatric surgery. Cannulae from two manufacturers were selected considering their design and outer and inner diameters. Cannula performance was evaluated in terms of pressure drop vs. flow during simulated cardiopulmonary bypass conditions. The experimental circuits consisted of a Jostra HL-20 roller pump, a Quadrox-i pediatric oxygenator (Maquet Cardiopulmonary AG, Rastatt, Germany), and a custom pediatric tubing set. The circuit was primed with lactated Ringer's solution only (first condition) and with human packed red blood cells added (second condition) to achieve a hematocrit of 30%. Cannula sizes 8 to 16 Fr were inserted into the cardiopulmonary bypass circuit with a "Y" connector. The flow was adjusted in 100 ml/min increments within typical flow ranges for each cannula. Pre-cannula and post-cannula pressures were measured to calculate the pressure drop. Utilizing a pressure drop limit of 100 mmHg, our results suggest a recommended flow limit of 500, 900, 1400, 2600, and 3100 mL/min for Braile arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, respectively. For Medtronic DLP arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, the recommended flow limit is 600, 1100, 1700, 2700, and 3300 mL/min, respectively. This study reinforces discrepancies in pressure drop between cannulae of the same diameter supplied by different manufacturers and the importance of independent translational research to evaluate components' performance.

Abstract 12644: FlowTriever Percutaneous Aspiration Thrombectomy: A Promising Approach to Catch a (Throm)Bus In-Transit

Introduction: Clot-in-transit (CIT) is a life-threatening emergency that occurs in about 25,000 patients annually and is associated with high mortality due to rapid cardiopulmonary collapse. This is a case of right atrial (RA) CIT extending from existing IVC filter in a patient with pulmonary embolism (PE) who underwent successful FlowTriever® catheter-based thrombectomy. Description of Case: A 60-year-old male presented with progressively worsening dyspnea on exertion, generalized weakness and fatigue, intermittent chest pain, and right leg pain with immobility for several weeks. He had a history of deep vein thrombosis (DVT), PE in 2008 treated with 18-month of warfarin. IVC filter was placed at that time for unclear indication. His initial labs showed elevated troponin-I of 34 ng/mL and NT pro-BNP of 3542 pg/mL, atrial flutter with 2:1 conduction, incomplete right bundle branch block, and old inferior infarct on ECG. Imaging revealed an extensive bilateral PE with right ventricle (RV) to left ventricle (LV) ratio of 2.3. Transthoracic echocardiogram (TTE) showed global LV dysfunction with ejection fraction of 44%, RV strain, dilated IVC, and an 8.7-cm mobile CIT in IVC extending into RA. Despite being treated with Heparin infusion, patient remained persistently tachycardic and dyspneic. Given his clinical stagnation due to CIT and submassive PE, he underwent an invasive TTE-guided percutaneous IVC and pulmonary arterial thrombectomy using Inari FlowTriever® catheter. Repeated TTE showed complete resolution of atrial thrombus. There was improvement in pulmonary arterial pressure and symptoms immediately post thrombectomy, but atrial flutter persisted. He was eventually discharged the following day with betablocker and life-long duration of anticoagulation. At follow up, he had complete resolution of symptoms and normal sinus rhythm on ECG. Discussion: Although surgical embolectomy is considered first-line therapy, percutaneous thrombectomy should be considered early for CIT to prevent of cardiopulmonary deterioration and shorter hospital course. FlowTriever® is the first device not requiring a cardiopulmonary bypass circuit to be FDA cleared for RA CIT, particularly benefiting patients who are poor surgical candidates.

Sternal protection technique for open chest management

On some occasions, postoperative mediastinal bleeding or right ventricular failure forces surgical teams to pursue a strategy of open-chest management and delayed sternal closure. One notable source of postoperative bleeding is the sternum, either due to medullar bleeding or bone margin oozing, which may be difficult to control. Furthermore, in cases with right ventricular failure or dilatation needing an open-chest strategy, sternal margins might erode and injure the right ventricular anterior wall. We propose a simple but effective sternal protection technique during open-chest management and further delayed chest closure. Using leftover tubing from the cardiopulmonary bypass circuit or a mediastinal 32 Fr drain, both sternal margins are covered and secured with sutures. Moreover, in case of profuse bleeding, a thrombin-derived haemostatic agent can be applied between the bone marrow and the tube for an additional level of haemostasis. The sternal wound is isolated with a latex membrane and covered with transparent sterile adhesive sheets to achieve vacuum sealing.

Effects of Blood Hemoadsorption Therapy with HA-380 in Total Arch Replacement for Acute Type A Aortic Dissection: A Retrospective Observational Study

Introduction: This study aimed to evaluate whether the addition of a hemoadsorption (HA) cartridge, HA-380, in the cardiopulmonary bypass (CPB) circuit in acute type A aortic dissection (ATAAD) surgery reduced inflammatory cytokine levels and decreased postoperative complications. Methods: A retrospective observational cohort study was conducted between March 1, 2021, and February 28, 2022. Patients with ATAAD undergoing emergent total arch replacement surgery were divided into the control (CON) and HA groups on the basis of the addition of the HA-380 cartridge in the CPB circuit. Results: Overall, 121 patients met the eligibility criteria; 2 patients in each group who died within the first postoperative week were excluded. Further, 57 and 60 patients in the CON and HA groups, respectively, were included in the pooled analysis. The major perioperative data, baseline values of interleukin-6 (IL-6) and C-reactive protein, and therapeutic interventions were similar in the two groups (all, p > 0.05). The serum IL-6 levels increased more rapidly in the CON group than those in the HA group postoperatively (205.73 ± 174.72 vs. 146.13 ± 64.15 pg/mL, p = 0.020). The HA group had a lower incidence of postoperative acute kidney injury (AKI) and severe acute respiratory distress syndrome than the CON group (25.4 vs. 44.6%, p = 0.032 and 18.3 vs. 35.1%, p = 0.040, respectively). Logistic regression analyses showed that HA may be a protective factor against postoperative AKI. The incidence of bleeding, delirium, and stroke as well as the lengths of intensive care unit and hospital stay in both groups were similar (all, p > 0.05). Conclusions: The use of HA-380 in the CPB circuit may attenuate inflammatory response and reduce major complications following ATAAD surgery. HA may be associated with lower rate of postoperative AKI.

IS THERE ANY SIGNIFICANT IMPACT OF TWO DIFFERENT BIO-COMPATIBLE COATED CARDIOPULMONARY BYPASS CIRCUITS ON CIRCULATING PLATELET DROP

Bleeding is common in cardiopulmonary bypass (CPB) surgery due to malfunctioning platelets. This study investigated the effect of a phosphorylcholine (PC)-coated CPB circuit and a balanced CPB circuit on platelet function. We conducted a descriptive, randomized trial at the Punjab Institute of Cardiology with 50 patients undergoing coronary artery bypass graft (CABG) surgery (n=34), valve surgery (n=10), and CABG plus valvular replacement (n=6) using CPB. The patients were divided into groups 1, which had phosphoryl-coated CPB, and 2, which had balanced-coated CPB. We measured and recorded pre- operative and post-operative levels of platelet count, white blood cells, and hemoglobin for both groups. We used the Student's t- test to make comparisons among groups, and the P values for both groups were less than 0.05 at a 95% confidence interval, indicating a significant impact of biocompatible coated CPB circuits on circulating platelet drop. Cohen's d formula showed that group 1 (Phosphoryl choline coating) had a more substantial effect on platelet drop than group 2 (Balanced coating). Blood component conservation, particularly platelet conservation, depends on the non-endothelium biocompatible surface used; the better the character, the more blood cells may be conserved. We looked at two coatings, phosphoryl coating, and balanced coating, to see if they substantially influenced platelet drop. According to the findings of our investigation, phosphoryl-coated CPB had a more significant influence on platelet drop than balanced coating.

Initial experience and outcomes with a hybrid extracorporeal membrane oxygenation and cardiopulmonary bypass circuit for lung transplantation

BackgroundThe utilization of extracorporeal life support (ECLS) for intraoperative support during lung transplantation has increased over the past decade. Although veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has recently emerged as the preferred modality over cardiopulmonary bypass (CPB), many centers continue to use both forms of ECLS during lung transplantation. Our novel hybrid VA-ECMO/CPB circuit allows for seamless transition from VA-ECMO to CPB at a significant cost savings compared to a standalone VA-ECMO circuit. This study describes our initial experience and outcomes in the first 100 bilateral lung transplantations using this novel hybrid VA-ECMO/CPB circuit. MethodsMedical records from September 2017 to May 2021 of the first 100 consecutive patients undergoing bilateral lung transplantation with intraoperative hybrid VA-ECMO support were examined retrospectively. We excluded patients with single lung transplants, retransplantations, preoperative ECLS bridging, and veno-venous (VV) ECMO and those supported with CPB only. Perioperative recipient, anesthetic, perfusion variables, and outcomes were assessed. ResultsOf the 100 patients supported with VA-ECMO, 19 were converted intraoperatively to CPB. Right ventricular dysfunction was seen in 37% of patients, and the median mean pulmonary artery pressure was 28 mm Hg. No oxygenator clotting was observed with a median heparin dose of 13,000 units in the VA-ECMO group. Primary graft dysfunction grade 3 at 72 hours was observed in 10.1% of all patients and observed 1-year mortality was 4%. ConclusionsThe use of a hybrid VA-ECMO/CPB circuit in our institution allows for rapid conversion to CPB with acceptable outcomes across a diverse recipient group at a significantly reduced cost compared to standalone VA-ECMO circuits.

A novel survival rat model of hyperkalemia and landiolol induced cardioplegic arrest and resuscitation via cardiopulmonary bypass.

A small animal model would be an effective tool for research on the pathophysiology of cardiopulmonary bypass (CPB). However, numerous CPB models do not involve myocardial arrest and resuscitation. The aim of this research is to establish an easily achievable myocardial arrest and resuscitation CPB model through hyperkalemia and landiolol, simulating clinical cardiac surgery. Ten Sprague-Dawley rats were chosen for CPB. Rats underwent sevoflurane inhalation induction anesthesia and were sustained in an anesthesia state by intubation and intraperitoneal injection's of esketamine and propofol. The entire CPB circuit include a reservoir, a membrane oxygenator and a roller pump, which were connected into a complete loop via silicon tubes and infusion tube.After CPB was established through the tail artery and internal jugular vein, cardioplegic arrest was induced and maintained for 5min at a rectum temperature of 28.5 ± 0.5°C with hyperkalemia and landiolol. Calcium chloride, epinephrine and insulin were then used for resuscitation. All rats successfully finished cardioplegic arrest, resuscitation procedure and survived 2h postoperatively. Mean hematocrit during CPB was significantly lower than physiologic values of the baseline. The mean time of arrest-resuscitation and CPB was 5.4 ± 0.8min and 98.5 ± 5.0min. The blood gas at each detection point were in range with the normal standard requirement of CPB. The establishment of cardioplegic arrest and resuscitation procedure via hyperkalemia and landiolol during CPB of WD rat could be achieved successfully. This animal model could be an alternative organ injury research on organ injury of patients undergoing cardiac surgery.

Plasmalyte and Ringer Lactate as Priming Solutions in Pediatric Cardiopulmonary Bypass: A Comparative Study

Background: Pediatric heart surgery, particularly for cyanotic congenital heart conditions, commonly requires the utilization of cardiopulmonary bypass (CPB) to assist with surgical interventions. The choice of priming solution for the CPB circuit can influence postoperative outcomes. This study aimed to assess the impact of two different priming solutions, Plasmalyte and Ringer's Lactate, on postoperative outcomes, blood biochemistry, pulmonary and renal function, bleeding, and hemostasis in children undergoing open cardiac surgery with CPB. Methods: This randomized prospective study was conducted on 80 pediatric patients aged 1 to 10 years, undergoing elective cardiac surgery with CPB. Patients were randomly assigned to receive either Plasmalyte (Group A) or Ringer's Lactate (Group B) as their CPB circuit priming solution. Standardized protocols for anesthesia, CPB circuit components, and surgical techniques were maintained. Postoperative parameters including blood chemistry, perfusion indicators, and physiological measurements were recorded and analyzed. Results: After CPB initiation, lactate levels were significantly higher in Group B (Ringer's Lactate) compared to Group A (Plasmalyte) (P-value &lt;0.001). Calcium levels also showed a significant difference between the two groups (P-value &lt;0.001). Postoperative lactate levels remained higher in Group B (P-value &lt;0.001), while bicarbonate, calcium, urine output, urea, and creatinine levels at 6th hour postoperatively were statistically significant (p&lt;0.05). Conclusions: Priming the CPB circuit with Plasmalyte may be associated with favorable outcomes in terms of lactate and calcium levels compared to Ringer Lactate in pediatric patients undergoing cardiac surgery.

Temporary venovenous extracorporeal membrane oxygenation after cardiopulmonary bypass in minimally invasive cardiac surgery via right minithoracotomy.

In minimally invasive cardiac surgery, it can be difficult at times to maintain adequate oxygenation with single-lung ventilation after weaning from cardiopulmonary bypass (CPB), and intermittent double-lung ventilation is required during hemostasis. Venovenous extracorporeal membrane oxygenation (VV-ECMO) after weaning from CPB eliminates the necessity of overinflation of the left lung and intermittent double-lung ventilation and enables secure and fast hemostasis. We investigated the effectiveness and safety of temporary VV-ECMO in MICS. Between May 2018 and March 2021, 149 patients underwent temporary VV-ECMO during minimally invasive cardiac surgery in our institutions. After weaning from CPB, the arterial circuit was reconnected to the right internal jugular venous cannula, the femoral venous cannula was pulled down by 20cm, and VV-ECMO was established using the CPB machine and cannulas. After starting VV-ECMO, we administered protamine and performed hemostasis. Operative data and outcomes were retrospectively reviewed. The mean VV-ECMO time and flow were 26 ± 13minutes and 2.38 ± 0.40L/m2, respectively. There was no thrombus in the CPB circuit, including the oxygenator. The trans-oxygenator pressure gradient index at the end of VV-ECMO significantly correlated with that at the start of VV-ECMO (r=0.88; 95% CI, 0.79-0.94; P=.01). The 30-day mortality rate was 2.0%. The incidences of unilateral pulmonary edema, prolonged ventilation, and re-exploration for bleeding were 2.7%, 5.4%, and 2.0%, respectively. Temporary VV-ECMO is safe and useful to maintain single-lung ventilation without overinflation after weaning from CPB for secure and fast hemostasis in minimally invasive cardiac surgery. No thrombotic event was found during temporary VV-ECMO without heparinization.

Utilizing retrograde autologous priming for blood conservation in cardiac surgery.

The use of crystalloid priming for extracorporeal circuit in adult cardiac surgery causes inevitable haemodilution. The haemodilution can be reduced by using methods such as retrograde autologous priming (RAP) with the patient's blood. This study compares the RAP technique with standard priming with regards to safety and the impact on haemodilution. This was a retrospective cohort study between a control group (n = 100) consisting of consecutive patients undergoing first time isolated coronary artery bypass surgery (CABG) with crystalloid priming solution in the circuit, and the RAP group (n = 100) consisting of patients undergoing isolated first time CABG with the RAP method. All demographics, procedure and perfusion data were gathered from the local surgical and perfusion database. Despite starting with comparable mean pre-operative haemoglobin (Hb) levels (control 127 mg/dL versus RAP 129 mg/dL), the RAP group had significantly higher mean post-op Hb level (109 mg/dL versus 92 mg/dL, P < 0.01). Crystalloid use was also significantly lower in RAP group (3.15 L versus 4.17 L P < 0.02). Freedom from red blood cell transfusion (86% versus 76% P = 0.038) and freedom from blood products (78% versus 66%, P = 0.032) was also significantly better in the RAP group. This study demonstrates that retrograde autologous priming is a safe and effective method for priming the cardiopulmonary bypass circuit in adult cardiac surgery, with significantly beneficial effects on transfusion rates and intra operative fluid requirements. Given these results the RAP method should be considered as a routine step in priming an extracorporeal circuit for adult cardiac operations.

#3285 EXTRACORPOREAL BLOOD PURIFICATION DURING OPEN HEART SURGERY WITH PROLONGED CPB: CYTOSORB 300 VS JAFRON HA330

Abstract Background and Aims Cardiac surgery is maintained by various complications. Major contribution associated with cardiopulmonary bypass (CBP). Cardiac surgery with CPB provokes activation of the cascade mechanism of inflammation with releasing of cytokines and a systemic inflammatory response syndrome (SIRS). Activation of the contact system due to exposure of artificial surface of the bypass circuit to blood cells, endotoxemia, ischemia and reperfusion injury and surgical trauma are all potential triggers of inflammation following CPB. This inflammatory reaction may leads to the development of postoperative complications, including vasoplegia, cytokine storm, myocardial dysfunction, respiratory failure, acute kidney injury, coagulopathy bleeding, and multiple organ dysfunction syndrome (MODS). A number of different strategies, including new pharmacologic agents, CPB circuits and components, and surgical techniques, have been employed during the last few years in attempts to minimize the impact of SIRS on the outcome of cardiac surgical patients. However, the complex pathophysiology of this problem has not allowed, until now, the use of a single strategy. The aim of our study is assessment of early application of extracorporeal cytokine adsorbers to the inflammation system during open-heart surgery with prolonged cardiopulmonary bypass. Method This prospective randomized single-center controlled trial observed patients, who were assigned a planned open cardiac surgery with a duration of cardiopulmonary bypass (CPB) more than 120 minutes between January 2021 to January 2023. Patients were randomized into three groups: CytoSorb -300 group, HA 330 group and the control group. A simple 1:1:1 randomization method was applied. Cytokine hemadsorption was conducted intraoperatively. Two types of cytokine cartridges were applied CytoSorb 300 (Cytosorbents Europe GmbH). НА330 (Jafron Biomedical Co., Ltd. China). The inclusion criteria: age ≥18 years, informed consent to participate in the study, CPB more than 120 min. The exclusion criteria: Age less than 18 years; refusal to participate in the study. Results The data of the HA 330 (n = 22) and CytoSorb300 (n = 22) groups were compared with the data of the control group (n = 22). The primary results and details of the work are given in Tables 1-3. Conclusion Intraoperative hemadsorption may be beneficial for patients who underwent open-heart surgery with prolonged CPB. The early hemadsorption has positive impact to postoperative period after cardiac surgery and may reduce requirement of renal replacement therapy.

P25: Assessment of VentriFlo True Pulse Pump in Cardiopulmonary Bypass Circuit In vivo

Objective: The objective of this study was to evaluate the hemodynamic and laboratory data during the post-cardiopulmonary bypass (CPB) phase in vivo in cardiovascular surgery utilizing the VentriFlo True Pulse Pump, a novel pulsatile extracorporeal blood pump capable of generating a natural-like pulse through standard oxygenators, cannulas, and tubing sets. Methods: The surgical procedure in porcine animal model (n=2, weight 26 and 23 kg) consisted of full median sternotomy access, central aortic cannulation, transatrial venous cannula insertion under general anesthesia. The intended duration of 3 hours has been maintained. In one case, a roller pump (RP) has been instituted. Second case has received the VentriFlo pulsatile pump (VentriFlo Inc., Pelham, NH). Hemodynamics were recorded during the CPB support period and for 3 hours post-CPB, and blood sampling was performed every hour. Results: The aortic pulse pressure was consistently higher with the VentriFlo pump compared to the RP (47 mm Hg vs. 25 mm Hg) (Figure 1). Although the pump flow during CPB was comparable (Both approximately 1.3 L/min), cardiac output was higher in the VentriFlo pig during the post-CPB period (1-3 hours) compared to the RP pig (2.2 L/min vs. 1.1 L/min). Regarding blood tests, the RP group exhibited a higher white blood cell count (21,800/uL vs. 13,150/uL in the VentriFlo pig). Conclusion: The VentriFlo pulsatile pump demonstrated the capability to deliver and maintain normal pulsatile flow and optimal cardiac output during and after CPB. More studies will be necessary to elucidate longer duration postoperative outcomes in cardiovascular surgical setup.Figure 1. Left – Aortic pulse pressure during the study. Middle – cardiac output post CPB. Right – WBC, white blood cell count. CPB, cardiopulmonary bypass.

TOP2: Miniature Extravascular Aortic Sensor for Continuous Blood Pressure Measurement: In-vivo Validation Under Pathological Conditions

Purpose of the Study: In individuals suffering from cardiovascular diseases, and especially in heart failure patients supported with left ventricular assist devices (VADs), the long-term monitoring of arterial blood pressure (ABP) holds significant value for assessing the disease progression, monitoring patient compliance, and evaluating the treatment efficacy. Hence, it is imperative to advance and extensively validate new, accurate and robust sensory technologies for this purpose. Methods: The present study aimed to evaluate the performance of a newly developed hall-based magnetic aortic sensor (HBSD) in monitoring arterial blood pressure (ABP) in conditions of low pulse pressures that simulate the hemodynamic conditions of VAD supported patients (Magkoutas et al, JACC: Basic to Translational Science, 2023). To this end, twelve acute in-vivo experiments were performed using pigs that were connected to a cardiopulmonary bypass circuit, and their hemodynamic state was regulated through adjustments to the support rate and pharmacological stimulation. In each experiment, two HBSDs were implanted, one in the ascending and one in the descending aorta. The reference ABP measurements were obtained using an intravascular fluid-filled catheter. Results: The pressure signal provided by the HBSD accurately captured the highly varying pressure profiles, regardless of the pressure level, CPB support level, and effective pulse pressure. The analysis of the difference between the end-diastolic (EDP), systolic (SP), and mean arterial (MAP) pressure values measured with the HBSDs and the reference sensors (Figure 1B) demonstrates that the HBSDs provide highly accurate measurements with a mean absolute error less than 5 mm Hg, except for two cases. Furthermore, the comparison of the entire dataset of the HBSD and the reference sensor during one of the in-vivo experiments reveals a high linear association between the two methods, confirmed by an intraclass coefficient higher than 0.95 (Figure 1C). The results of the Bland-Altman plot in Figure 1D also indicate that the developed HBSD has a mean bias of 0 mmHg, with limits of agreement approximately equal to 8.5 mmHg, compared to the reference pressure sensor. Conclusion: This study provides evidence supporting the accuracy of the proposed HBSD in measuring the ABP waveform in pathological and varying hemodynamic conditions. This constitutes a crucial preliminary stage in advancing the HBSD towards clinical utilization, thereby unlocking the valuable information contained in the ABP waveform and enhancing patient surveillance and therapeutic intervention in individuals supported by VADs.Figure 1. A) Implantation procedure and components of the hall-based aortic sensor. B) Boxplots of the difference between the end-diastolic (EDP), systolic (SP), and mean arterial (MAP) pressure values measured with the HBSDs and the reference sensors. C) The intraclass coefficient (ICC) with 95% confidence intervals for the ABP measured with the HBSD and the reference ABP. D) Bland-Altman plot with the representation of the mean difference, the limits of agreement (LoA) (dashed line) from −1.96s to +1.96s, and 95% confidence intervals (CI).

Exogenous nitric oxide delivery protects against cardiopulmonary bypass–associated acute kidney injury: Histologic and serologic evidence from an ovine model

ObjectiveSeveral human studies have associated nitric oxide administration via the cardiopulmonary bypass circuit with decreased incidence of cardiopulmonary bypass–associated acute kidney injury, but histopathologic and serologic evidence of nitric oxide efficacy for acute kidney injury attenuation are lacking. MethodsBy using a survival ovine model (72 hours), acute kidney injury was induced by implementing low-flow cardiopulmonary bypass for 2 hours, followed by full-flow cardiopulmonary bypass for 2 hours. The nitric oxide cohort (n = 6) received exogenous nitric oxide through the cardiopulmonary bypass circuit via the oxygenator, and the control group (n = 5) received no nitric oxide. Serial serologic biomarkers and renal histopathology were obtained. ResultsBaseline characteristics (age, weight) and intraoperative parameters (cardiopulmonary bypass time, urine output, heart rate, arterial pH, and lactate) were equivalent (P > .10) between groups. Postoperatively, urine output, heart rate, respiratory rate, and peripheral arterial saturation were equivalent (P > .10) between groups. Post–cardiopulmonary bypass creatinine elevations from baseline were significantly greater in the control group versus the nitric oxide group at 16, 24, and 48 hours (all P < .05). Histopathologic evidence of moderate/severe acute kidney injury (epithelial necrosis, tubular slough, cast formation, glomerular edema) occurred in 60% (3/5) of the control group versus 0% (0/6) of the nitric oxide group. Cortical tubular epithelial cilia lengthening (a sensitive sign of cellular injury) was significantly greater in the control group than in the nitric oxide group (P = .012). ConclusionsIn a survival ovine cardiopulmonary bypass model, nitric oxide administered with cardiopulmonary bypass demonstrated serologic and histologic evidence of renal protection from acute kidney injury. These results provide insight into 1 potential mechanism for cardiopulmonary bypass–associated acute kidney injury and supports continued study of nitric oxide via cardiopulmonary bypass circuit for prevention of acute kidney injury.