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Background: Pump exchange is an established strategy to treat LVAD‐related complications such as thrombosis, infection, and driveline failure. Pump upgrades with an exchange to newer generation devices are being performed to the advantage of the patient on long‐term support. The safety and efficacy of a repeat LVAD exchange with a concomitant upgrade to a third‐generation pump have not been reported. Methods: We performed a retrospective analysis of all consecutive patients who underwent a repeat LVAD device exchange and upgrade to HeartMate III (HMIII) at Houston Methodist Hospital between December 2018 and December 2020. Results: Five patients underwent exchange and upgrade to HMIII within the specified timeframe. Four patients had already had two prior exchanges (all HMII to HMII), and one patient had one prior exchange (HVAD to HVAD). In all cases, implantation was performed as destination therapy. The surgical exchange was performed via redo median sternotomy on full cardiopulmonary bypass. No unplanned redo surgery of the device component was required. In‐hospital mortality was 20% in this very high‐risk population. At 1‐, 3‐, and 6‐month follow‐up, all discharged patients were on HMIII support, with no major LVAD‐related adverse events reported. Conclusion: We report the feasibility and safety of a repeat pump exchange with an upgrade to HMIII in a high‐volume center. The decision for medical therapy versus surgical exchange has to be tailored to individual cases based on risk factors and clinical stability but in expert hands, even a re‐redo surgical approach grants options for good medium‐term outcomes. [ABSTRACT FROM AUTHOR]

Background: Extracorporeal life support (ECLS) has extensive applications in managing patients with acute cardiac and pulmonary failure. Two primary modalities of ECLS, cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO), include several similarities in their composition, complications, and patient outcomes. Both CPB and ECMO pose a high risk of thrombus formation and platelet activation due to the large surface area of the devices and bleeding due to system anticoagulation. Therefore, novel methods of anticoagulation are needed to reduce the morbidity and mortality associated with extracorporeal support. Nitric oxide (NO) has potent antiplatelet properties and presents a promising alternative or addition to anticoagulation with heparin during extracorporeal support. Methods: We developed two ex vivo models of CPB and ECMO to investigate NO effects on anticoagulation and inflammation in these systems. Results: Sole addition of NO as an anticoagulant was not successful in preventing thrombus formation in the ex vivo setups, therefore a combination of low‐level heparin with NO was used. Antiplatelet effects were observed in the ex vivo ECMO model when NO was delivered at 80 ppm. Platelet count was preserved after 480 min when NO was delivered at 30 ppm. Conclusion: Combined delivery of NO and heparin did not improve haemocompatibility in either ex vivo model of CPB and ECMO. Anti‐inflammatory effects of NO in ECMO systems have to be evaluated further. [ABSTRACT FROM AUTHOR]

Background: Left ventricular assist device (LVAD) implantation via thoracotomy has many potential advantages compared to conventional sternotomy, including improved inflow cannula (IFC) positioning. We compared the difference in IFC angles, postoperative, and long‐term outcomes for patients with LVADs implanted via thoracotomy and sternotomy. Methods: A single‐center, retrospective analysis of 14 patients who underwent thoracotomy implantation was performed and matched with 28 patients who underwent sternotomy LVAD implantations for a total of 42 patients. Inclusion required a minimum LVAD support duration of 30 days and excluded concomitant procedures. A postoperative CT‐chest was used to measure the angle the between the IFC and mitral valve in two‐dimensions and results were compared with three‐dimensional reconstruction using the same CT chest. Outcome data were extracted from medical records. Results: There was no significant difference in gender, INTERMACS score, BMI, or age between the two groups. Median cardiopulmonary bypass time was longer in the thoracotomy group compared to the sternotomy group, 107 min (86–122) versus 76 min (56–93), p < 0.01. 3D reconstructions revealed less deviation of the IFC away from the mitral valve in devices implanted via thoracotomy compared to sternotomy, median (IQR) angle 16.3° (13.9°–21.0°) versus 23.2° (17.9°–26.4°), p < 0.01. Rates of pump thrombosis, stroke, and gastrointestinal bleeding were not significantly different. Conclusions: Devices implanted via thoracotomy demonstrated less deviation away from mitral valve. However, there was no difference in morbidity between the two approaches. 3D reconstruction of the heart is an innovative technique to measure angulation and is clinically advantageous when compared to 2D imaging. [ABSTRACT FROM AUTHOR]

Background: Processes that activate the immune system during lung transplantation can lead to primary graft dysfunction (PGD) or allograft rejection. Methods: We analyzed cytokine expression profiles after reperfusion and allograft outcomes in a cohort of patients (n = 59) who underwent lung transplantation off‐pump (n = 26), with cardiopulmonary bypass (CPB; n = 18), or with extracorporeal membrane oxygenation (ECMO; n = 15). Peripheral blood was collected from patients at baseline and at 6 and 72 h after reperfusion. To adjust for clinical differences between groups, we utilized a linear mixed model with overlap weighting. Results: PGD3 was present at 48 or 72 h after reperfusion in 7.7% (2/26) of off‐pump cases, 20.0% (3/15) of ECMO cases, and 38.9% (7/18) of CPB cases (p = 0.04). The ECMO and CPB groups had greater reperfusion‐induced increases in MIP‐1B, IL‐6, IL‐8, IL‐9, IL1‐ra, TNF‐alpha, RANTES, eotaxin, IP‐10, and MCP‐1 levels than the off‐pump group. Cytokine expression profiles after reperfusion were not significantly different between ECMO and CPB groups. Conclusion: Our data suggest that, compared with an off‐pump approach, the intraoperative use of ECMO or CPB during lung transplantation is associated with greater reperfusion‐induced cytokine release and graft injury. [ABSTRACT FROM AUTHOR]

Over the last half‐century, left ventricular assist device (LVAD) technology has progressed from conceptual therapy for failed cardiopulmonary bypass weaning to an accepted destination therapy for advanced heart failure. The history of LVAD engineering is defined by an initial development phase, which demonstrated the feasibility of such an approach, to the more recent three major generations of commercial devices. In this review, we explore the engineering challenges of LVADs, how they were addressed over time, and the clinical outcomes that resulted from each major technological development. The first generation of commercial LVADs were pulsatile devices, which lacked the appropriate durability due to their number of moving components and hemocompatibility. The second generation of LVADs was defined by replacement of complex, pulsatile pumps with primarily axial, continuous‐flow systems with an impeller in the blood passageway. These devices experienced significant commercial success, but the presence of excessive trauma to the blood and in‐situ bearing resulted in an unacceptable burden of adverse events. Third generation centrifugal‐flow pumps use magnetically suspended rotors within the pump chamber. Superior outcomes with this newest generation of devices have been observed, particularly with respect to hemocompatibility‐related adverse events including pump thrombosis, with fully magnetically levitated devices. The future of LVAD engineering includes wireless charging foregoing percutaneous drivelines and more advanced pump control mechanisms, including synchronization of the pump flow with the native cardiac cycle, and varying pump output based on degree of physical exertion using sensor or advanced device‐level data triggers. [ABSTRACT FROM AUTHOR]

Background: Extracorporeal membrane oxygenation (ECMO) represents an advanced option for supporting refractory respiratory and/or cardiac failure. Systemic anticoagulation with unfractionated heparin (UFH) is routinely used. However, patients with bleeding risk and/or heparin‐related side effects may necessitate alternative strategies: among these, nafamostat mesilate (NM) has been reported. Methods: We conducted a systematic literature search (PubMed and EMBASE, updated 12/08/2021), including all studies reporting NM anticoagulation for ECMO. We focused on reasons for starting NM, its dose and the anticoagulation monitoring approach, the incidence of bleeding/thrombosis complications, the NM‐related side effects, ECMO weaning, and mortality. Results: The search revealed 11 relevant findings, all with retrospective design. Of these, three large studies reported a control group receiving UFH, the other were case series (n = 3) or case reports (n = 5). The main reason reported for NM use was an ongoing or high risk of bleeding. The NM dose varied largely as did the anticoagulation monitoring approach. The average NM dose ranged from 0.46 to 0.67 mg/kg/h, but two groups of authors reported larger doses when monitoring anticoagulation with ACT. Conflicting findings were found on bleeding and thrombosis. The only NM‐related side effect was hyperkalemia (n = 2 studies) with an incidence of 15%–18% in patients anticoagulated with NM. Weaning and survival varied across studies. Conclusion: Anticoagulation with NM in ECMO has not been prospectively studied. While several centers have experience with this approach in high‐risk patients, prospective studies are warranted to establish the optimal space of this approach in ECMO. [ABSTRACT FROM AUTHOR]

Background: Non‐pulsatile cardiopulmonary bypass (CPB) may induce microvascular dysregulation. In piglets, we compared ocular surface microcirculation during pulsatile versus continuous flow (CF) bypass. Methods: Ocular surface microcirculation in small tissue volumes (~0.1 mm3) at limbus (high metabolic rate) and bulbar conjunctiva (low metabolic rate) was examined in a porcine model using computer assisted video microscopy and diffuse reflectance spectroscopy, before and after 3 and 6 h of pulsatile (n = 5 piglets) or CF (n = 3 piglets) CPB. Functional capillary density, capillary flow velocity and microvascular oxygen saturation were quantified. Results: At limbus, velocities improved with pulsatility (p < 0.01) and deteriorated with CF (p < 0.01). In bulbar conjunctiva, velocities were severely reduced with CF (p < 0.01), accompanied by an increase in capillary density (p < 0.01). Microvascular oxygen saturation decreased in both groups. Conclusion: Ocular surface capillary densities and flow patterns are better preserved with pulsatile versus CF during 6 h of CPB in sleeping piglets. [ABSTRACT FROM AUTHOR]

Background: Cardiopulmonary bypass (CPB) during left ventricular assist device (LVAD) implantation provides circulatory support and allows for safe inspection of the left ventricle (LV), whereas circulatory support by veno‐arterial extracorporeal life support (va‐ECLS) or off‐pump implantation may reduce postoperative bleeding and inflammatory response. Methods: Retrospective analysis of 616 consecutive adult patients who received an LVAD via median sternotomy between January 1, 2015 and December 31, 2019. All patients undergoing concomitant intracardiac procedures other than closure of persistent foramen ovale or atrial septal defect and redo surgeries were excluded from the analysis. The remaining patients (n = 222) were divided into two groups and 1:1 propensity score‐matched regarding preoperative parameters: patients who underwent LVAD implantation with LV inspection employing CPB (CPB group, n = 62) and without LV inspection on va‐ECLS or off‐pump (non‐CPB group, n = 62). Results: The groups were well balanced with regard to preoperative baseline characteristics (standard difference <0.1). Patients in the CPB group required more blood transfusions (median 2 vs. 0 units, p = 0.031) during surgery and in the first 24 h afterwards. The median intensive care unit stay was longer in the CPB group (18 vs. 11 days, p = 0.021). The CPB group showed an absence of perioperative stroke and a smaller number of events per patient‐year for postoperative ischemic stroke (0.02 vs. 0.12, p = 0.003). 30‐day survival (87% vs. 87.1%) and 1‐year survival (80.3% vs. 74%) were similar in both groups (p = 0.78). Conclusion: Visual LV inspection on CPB may reduce the risk of postoperative ischemic stroke. Despite the negative effects of employing CPB in lieu of other intraoperative strategies, survival was similar in both groups. [ABSTRACT FROM AUTHOR]

Background: Data from large cardiac surgery registries have been depicting a downward trend of mortality and morbidities in the last 20 years. However, despite decades of medical evolution, cardiac surgery and cardiopulmonary bypass still provoke a systemic inflammatory response, which occasionally leads to worsened outcome. This article seeks to outline the mechanism of the phenomenon. Methods: A thorough review of the literature has been performed. Criteria for considering studies for this non‐systematic review were as follows: observational and interventional studies investigating the systemic inflammatory response to cardiac surgery, experimental studies describing relevant molecular mechanisms, and essential review studies pertinent to the topic. Results: The intrinsic variability of the inflammatory response to cardiac surgery, together with its heterogenous perception among clinicians, as well as the arduousness to early discriminate high‐responder patients from those who will not develop a clinically relevant reaction, concurred to hitherto unconclusive randomized controlled trials. Furthermore, peremptory knowledge about the pathophysiology of maladaptive inflammation following heart surgery is still lacking. Conclusions: Systemic inflammation following cardiac surgery is a frequent entity that occasionally becomes clinically relevant. Specific genomic differences, age, and other preoperative factors influence the magnitude of the response, which elements display extreme redundancy and pleiotropism that the target of a single pathway cannot represent a silver bullet. [ABSTRACT FROM AUTHOR]

Background: The VentriFlo® True Pulse Pump (VentriFlo, Inc, Pelham, NH, USA) is a new pulsatile blood pump intended for use during short‐term circulatory support. The purpose of this study was to evaluate the feasibility of the VentriFlo and compare it to a conventional centrifugal pump (ROTAFLOW, Getinge, Gothenberg, Sweden) in acute pig experiments. Methods: Pigs (40–45 kg) were supported by cardiopulmonary bypass (CPB) with the VentriFlo (n = 9) or ROTAFLOW (n = 5) for 6 h. Both VentriFlo and ROTAFLOW circuits utilized standard CPB components. We evaluated hemodynamics, blood chemistry, gas analysis, plasma hemoglobin, and microcirculation at the groin skin with computer‐assisted video microscopy (Optilia, Sollentuna, Sweden). Results: Pigs were successfully supported by CPB for 6 h without any pump‐related complications in either group. The VentriFlo delivered an average stroke volume of 29.2 ± 4.8 ml. VentriFlo delivered significantly higher pulse pressure (29.1 ± 7.2 mm Hg vs. 4.4 ± 7.0 mm Hg, p < 0.01) as measured in the carotid artery, with mean aortic pressure and pump flow comparable with those in ROTAFLOW. In blood gas analysis, arterial pH was significantly lower after five hours support in the VentriFlo group (7.30 ± 0.07 vs. 7.43 ± 0.03, p = 0.001). There was no significant difference in plasma hemoglobin level in both groups after six hours of CPB support. In microcirculatory assessment, VentriFlo tended to keep normal capillary flow, but it was not statistically significant. Conclusions: VentriFlo‐supported pigs showed comparable hemodynamic parameters with significantly higher pulse pressure compared to ROTAFLOW without hemolysis. [ABSTRACT FROM AUTHOR]

Background: Major airway surgery can pose a complex problem to perioperative central airway management. Adjuncts to advanced ventilation strategies have included cardiopulmonary bypass, veno‐arterial, or veno‐venous extracorporeal life support. We performed a systematic review to assess the existing evidence utilizing these strategies. Methods: An electronic search was conducted to identify studies written in English reporting the use of extracorporeal life support (ECLS) during central airway surgery. Thirty‐six articles consisting of 78 patients were selected and patient‐level data were analyzed. Results: Median patient age was 47 [IQR: 34‐53] and 59.0% (46/78) were male. Indications for surgery included central airway or mediastinal cancer in 57.7% (45/78), lesion or injury in 15.4% (12/78), and stenosis in 12.8% (10/78). Support was initiated pre‐operatively in 9.9% (7/71) and at the time of induction in 55.3% (42/76). It was most commonly used at the time of tracheal resection/repair [93.2% (68/73)], intubation of the tracheal stump [94.4% (68/72)], and re‐anastomosis [94.2% (65/69)]; 13.7% (10/73) patients were supported post‐operatively. The most commonly performed surgery was tracheal repair or resection in 70.3% (52/74). Median hospital stay was 12 [8, 25] days and in‐hospital mortality was 7.9% (6/76). There was no significant difference in survival between the three groups (p =.54). Conclusions: Extracorporeal membrane oxygenation offers versatility in timing, surgical approach, and ECLS runtime that makes it a viable addition to the surgical armamentarium for treating complex central airway pathologies. [ABSTRACT FROM AUTHOR]

Coagulopathy is common during left ventricular assist device (LVAD) implantation, treatment of which can be challenging given the often‐limited ability for the right ventricle to accommodate volume transfusion after device initiation with 20% to 40% of patients developing right ventricular failure (RVF). Transfusion of plasma late on cardiopulmonary bypass (CPB) combined with ultrafiltration may replace clotting factors while reducing volume administration. We compared outcomes in patients undergoing LVAD implantation receiving plasma on CPB and ultrafiltration with traditional transfusion practices. Co‐primary outcomes needed for blood product transfusion in the first 6 and 24 hours after CPB. Secondary outcomes included metrics of morbidity and mortality. 396 patients were analyzed (59 plasma on CPB). Patients receiving plasma on CPB had a greater volume of blood products transfused (3764 vs. 2741 mL first 6 hours; 6059 vs. 4305 mL first 24 hours) in unadjusted analysis. In adjusted analysis, plasma transfusion on CPB with ultrafiltration had no significant effect on the primary outcomes of blood products given in the first 6 hours (estimated effect size 982 [−428, 2392] mL, P =.17) and 24 hours (estimated effect size 1076 [−904, 3057] mL, P =.29). Patients receiving plasma on CPB were more likely on either vasopressors or inotropes at 24 hours after ICU admission (P =.01), however, indices of coagulopathy and RVF were similar between groups. While prospective studies would be necessary to definitively evaluate the clinical utility of this strategy, no signal for benefit was observed suggesting plasma should not be used for this purpose. [ABSTRACT FROM AUTHOR]

Although de‐airing procedures are commonly performed during cardiac surgery, use of these procedures is not necessarily based on evidence. Uncertainly remains around the size of bubbles that can be detected by echocardiography, whether embolized air or carbon dioxide can be absorbed, and the reasons for embolic events occurring despite extensive de‐airing. Since air bubbles are invisible in the blood, we used simple experimental models employing water and 10% dextran solution to determine the correlation between actual bubble size and the depicted size on echocardiography, bubble size, and floatation velocity and the absorption of carbon dioxide under embolization and irrigation conditions. Bubbles depicted as larger than 1 mm were overestimated by echocardiography: the actual size was larger than 0.4 mm in diameter. While bubbles of 0.5 mm had a floatation velocity of 2 to 3 cm/s, the buoyancy of bubbles smaller than 0.3 mm was negligible. Thus, bubbles that are depicted as larger than 1 mm on echocardiography or that present with apparent buoyancy should be visible and need to be meticulously removed. However, echocardiography cannot distinguish bubbles of around 0.1 mm in diameter from those of capillary size (<10 μm). Thus, we advise continuous venting of dense bubbles until they become sparse. While carbon dioxide was rapidly absorbed when circulating, the absorption of embolized carbon dioxide was negligible. These results suggest that detected intracardiac air represents residual "air," with carbon dioxide already absorbed. Therefore, the use of conventional de‐airing procedures needs reconsideration: air and buoyant bubbles should be removed from the heart before they are expelled into the aorta; this requires timely and precise assessment with transesophageal echocardiography and effective collaboration between surgeons, anesthesiologists, and perfusionists. [ABSTRACT FROM AUTHOR]

The use of pulsatile perfusion instead of nonpulsatile perfusion during cardiopulmonary bypass continues to be a source of debate. The disagreements among the conclusions of the published studies may be due to different factors: differences in the type of patients included in the studies, differences in the protocol of the studies, and difficulty to quantify the pulsatility of the flow. In the present paper, we propose a quantitative evaluation of Shepard's energy equivalent pressure index, based on the harmonic decomposition of the physiological aortic pressure and flow rate signal. It is thus demonstrated that the surplus energy provided by pulsatile flow remains moderate (of order 10 mm Hg), but that it can be improved by changing the relative shapes of the pressure and flow waves. [ABSTRACT FROM AUTHOR]

Pediatric patients are particularly prone to cardiopulmonary bypass (CPB)‐induced coagulopathy mainly due to hemodilution, consumption of coagulation factors and hypothermia. The aim of the present study was to examine the possible role of platelet count and function as it relates to the bleeding risk after CPB in the pediatric population. All consecutive patients (age <13 years) scheduled for elective cardiac surgery between January 2019 and November 2019 were retrospectively considered for the study. We gathered demographic characteristics, perioperative laboratory data (mainly platelet count and function), transfusion requirements, and blood loss for each patient. Patients with a chest tube output during the first 24 hours after surgery >75th percentile were bleeders (cases). Controls were nonbleeders. A total of 31 patients were enrolled [median age 17 (4‐57) months]. A significant postoperative reduction in platelet count (P <.001) and function either in ADP‐test (P <.001), TRAP‐test (P <.001) and ASPI‐test (P <.001) was found, with positive correlations between chest tube output within the first 24 hours after surgery and postoperative impairment of platelet count (R = 0.553, P =.001), ADP‐test (R = 0.543, P =.001), TRAP‐test (R = 0.627, P <.001) and ASPI‐test (R = 0.436, P =.014). Eight children (26%) experienced major postoperative bleeding. Bleeders were significantly younger (P =.015) and underwent longer CPB duration (P =.015). Despite no significant differences in postoperative platelet count and function between cases and controls, the postoperative reduction (Δ) in platelet count (P =.002) and function in ADP‐test (P =.007), TRAP‐test (P =.020) and ASPI‐test (P =.042) was significantly greater in bleeders vs. nonbleeders. A ΔPLT >262 500 ×109/L, a ΔADP‐test >29 U, a ΔTRAP‐test >44 U and a ΔASPI‐test >26 U showed to be predictive of major postoperative bleeding. Postoperative bleeding in children undergoing cardiac surgery with CPB was linked to younger age, longer CPB duration, and significant postoperative reduction in platelet count and function. Larger studies are needed to confirm our results and define strategies to reduce postoperative bleeding in these patients. [ABSTRACT FROM AUTHOR]

Neurological dysfunction commonly occurs after cardiac surgery with deep hypothermic circulatory arrest (DHCA). The mechanisms underlying DHCA‐associated brain injury remain poorly understood. This study determined the changes in expression profiles of circular RNAs (circRNAs) in the hippocampus in rats that underwent DHCA, with an attempt to explore the potential role of circRNAs in the brain injury associated with DHCA. Adult male Sprague Dawley rats were subjected to cardiopulmonary bypass with DHCA. Brain injury was evaluated by neurological severity scores and histological as well as transmission electron microscope examinations. The expression profiles of circRNAs in the hippocampal tissues were screened by microarray. Quantitative real‐time PCR (RT‐qPCR) was used to validate the reliability of the microarray results. Bioinformatic algorithms were applied to construct a competing endogenous RNA (ceRNA) network, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to explore the potential biological roles of the circRNAs. Out of 14 145 circRNAs screened, 56 were differentially expressed in the hippocampus between the DHCA and sham‐operated rats, including 30 upregulated and 26 downregulated circRNAs. The expression changes of six selected circRNAs (upregulated: rno_circRNA_011190, rno_circRNA_012988, rno_circRNA_000544; downregulated: rno_circRNA_010393, rno_circRNA_012043, rno_circRNA_015149) were further confirmed by RT‐qPCR. Bioinformatics analysis showed the enrichment of these confirmed circRNAs and their potential target mRNAs in several KEGG pathways including histidine metabolism, adipocytokine signaling, and cAMP signaling. By revealing the change expression profiles of circRNAs in the brain after DHCA, this study indicates possible involvements of these dysregulated circRNAs in brain injury and suggests a potential of targeting circRNAs for prevention and treatment of neurological dysfunction associated with DHCA. [ABSTRACT FROM AUTHOR]

Perventricular pulmonary valve implantation (PPVI) of a xenograft valve can be a less invasive technique that avoids cardiopulmonary bypass in patients who require pulmonary valve replacement. We compared the hemodynamics, durability, and histologic changes between two different xenogenic valves (pericardial vs. aortic valve porcine xenografts) implanted into the pulmonary valve position using a PPVI technique and evaluated the safety and efficacy of PPVI as a preclinical study. In 18 sheep, pericardial (group porcine pericardial [PP], n = 9) or aortic valve (group porcine aortic valve [PAV], n = 9) xenogenic porcine valves manufactured as a stented valve were implanted using a PPVI technique. The porcine tissues were decellularized, alpha‐galactosidase treated, fixed with glutaraldehyde after space‐filler treatment, and detoxified to improve durability. Hemodynamic and immunohistochemical studies were performed after the implantation; radiologic and histologic studies were performed after a terminal procedure. All stented valves were positioned properly after the implantation, and echocardiography and cardiac catheterization demonstrated good hemodynamic state and function of the valves. All the anti‐α‐Gal IgM and IgG titers were below 0.3 optical density. Computed tomography of extracted valves demonstrated no significant differences in the degree of calcification between the two groups (P =.927). Microscopic findings revealed a minimal amount of calcification and no significant infiltration of macrophage or T‐cell in both groups, regardless of the implantation duration. The PPVI is a feasible technique. Both stented valves made of PP and PAV showed no significant differences in hemodynamic profile, midterm durability, and degree of degenerative dystrophic calcification. [ABSTRACT FROM AUTHOR]

In donation after circulatory death heart transplantation, the donor heart is exposed to circulatory load. The right ventricle, due to its structure, has high compliance for volume load but is particularly vulnerable to increased pressure load. This study used a porcine model to conduct a functional assessment of the hemodynamics of the heart, with a focus on the right ventricle. Six pigs weighing 24.6 ± 1.4 kg were used. Circulatory death was induced by asphyxiation after median sternotomy. After 30 minutes in the state of global warm ischemia, the ascending aorta was clamped, followed by a 20‐minute reperfusion of the heart with a 20°C blood cardioplegia solution. Systemic circulation was established by cardiopulmonary bypass after aortic cross‐clamping. After initial reperfusion, the blood cardioplegia solution was replaced with blood. The blood was then rewarmed while the heart was still in a non‐working state. Cardiac function was assessed twice in situ, first by the thermodilution method, and then, by the pressure–volume measurement both at preischemia and at three hours after initiation of reperfusion. The recovery rate of cardiac output was 75%. End‐systolic elastance (P =.02) and pulmonary arterial elastance significantly increased (P =.03), but the ratio of arterial elastance to end‐systolic elastance was preserved (P =.91) in the right ventricle. Despite a decrease in cardiac output after reperfusion from warm ischemia, the right ventricle had a potential to respond the elevated afterload. It is important that donations after circulatory death heart transplantation should be performed with attention to avoiding right ventricular distension. [ABSTRACT FROM AUTHOR]

Hemolysis in cardiac surgery is often related to the contact of blood with air or artificial surfaces. Variations of negative pressure in the suction cannulas may represent an additional factor. Limited data exist on the contribution of a roller pump‐assisted (RPA) cardiotomy suction unit to hemolysis. Elevation of free hemoglobin (fHb) following air suction (AS) or suction tip occlusion (STO) events of a pump‐assisted cardiotomy suction unit was investigated in a mock circuit filled with blood from slaughtered domestic pigs. AS‐associated hemolysis was measured over 240 minutes with 2 minutes of AS occurring every 10 minutes. STO‐associated hemolysis was analyzed over 80‐minute periods: configuration 1 (c1) comprised a cycle of 20 minutes (min) occlusion and 60 minutes RPA flow (20/60 minutes); c2 comprised 20 cycles of 1/3 minutes; c3 comprised 40 cycles of 0.5/1.5 minutes; and c4 comprised 80 cycles of 0.25/0.75 minutes. The AS setup did not lead to significant hemolysis after 2 (P =.97), 3 (P =.40) or 4 (P =.11) hours. The STO setup showed the greatest hemolysis (ΔfHb of 30 mg/dL) in c1 after 20 minutes. ΔfHb was different in c1 from all other configurations at 20 minutes (P <.0001) and 80 minutes (P <.05). Ex vivo generation of large negative pressures by STO events is the main cause of cardiotomy suction‐associated hemolysis. The clinical relevance of this mechanism needs further investigations. [ABSTRACT FROM AUTHOR]

Our objective was to assess the effect of nitric oxide added to the sweep gas of the oxygenator during cardiopulmonary bypass (CPB) in infants on platelet count, platelet function, clinical outcomes, and safety. A randomized, double‐blinded, placebo‐controlled clinical trial in infants less than a year of age undergoing cardiac surgery requiring CPB was undertaken. Nitric oxide at a dose of 20 ppm was added to the sweep gas in the treatment group. Blood was collected at baseline and prior to separation from CPB to measure platelet count and function as determined by responsiveness to specific agonists. Clinical outcomes were observed through hospital discharge. Methemoglobin levels were measured preoperatively, at the conclusion of CPB, and upon admission to the ICU. Forty patients consented and were randomized in the trial. Eighteen patients were randomized to the treatment group and 22 were included in the placebo group. The groups were similar in terms of age, weight, gender, and surgical complexity. No significant differences were found in measures of platelet count, platelet response to agonist, or clinical outcomes. Patients in the treatment group had higher methemoglobin levels after receiving nitric oxide, but no levels approached toxicity (maximum 2.4%). Nitric oxide added to the sweep gas of the oxygenator during CPB in infants did not have an appreciable effect on the preservation of platelet count, platelet responsiveness to agonist, or clinical outcomes. Methemoglobin levels were increased after receiving nitric oxide but were far below a toxic level of 15%. [ABSTRACT FROM AUTHOR]

Mechanical heart valves left in situ at the time of left ventricular assist device (LVAD) implantation are thought to potentially increase the risk of thromboembolism. Recommendations exist to replace dysfunctional mechanical mitral valves and any mechanical aortic valves at the time of LVAD implantation. Due to potential increases in cardiopulmonary bypass time and associated comorbidities with valve replacement, leaving a functional mechanical valve in place at LVAD implantation has been suggested to be a safe option. We retrospectively reviewed all patients with prior mechanical mitral or aortic valves undergoing LVAD implantation at our center between 2012 and 2017. Echocardiograms were read by a single cardiologist to assess for mechanical valve dysfunction. We identified 15 patients. Five patients had major bleeding requiring transfusion. On follow‐up, 2 patients had hemorrhagic stroke and 2 had transient ischemic attach/ischemic stroke. In addition, 2 patients had LVAD thrombosis and 2 patients had LVAD driveline malfunction. Mild mechanical valve regurgitation was identified on follow‐up echocardiograms of 2 patients. Rate of complications in patients with mechanical valves undergoing LVAD implantation was comparable to that reported for the general LVAD population. Leaving a functional mechanical valve in place at the time of LVAD implantation could be a reasonable alternative to valve replacement. More data are required to further guide patient care in these individuals. [ABSTRACT FROM AUTHOR]

Having physiological correct flow waveforms is a key feature for experimental studies of blood flow, especially in the process of developing and testing a new medical device such as stent, mechanical heart valve, or any implantable medical device that involves circulation of blood through the device. It is also a critical part of a perfusion system for cardiopulmonary bypass and extracorporeal membrane oxygenation procedures. This study investigated the feasibility of a novel roller pump for use in experimental flow phantoms. Flow rates of carotid flow profile measured directly with the ultrasonic flow meter matched well with the reference flow rates programmed into the machine with similarity index of 0.97 and measured versus programmed flow rates at specific time‐points of peak systolic velocity (PSV): 0.894 vs 0.880, end systolic velocity (ESV): 0.333 vs 0.319, and peak diastolic velocity (PDV): 0.514 vs 0.520 L/min. Flow rates derived from video analysis of the pump motion for carotid, suprarenal, and infrarenal flows also matched well with references with similarity indices of 0.99, 0.99, and 0.96, respectively. Measured flow rates (mean/standard deviation) at PSV, ESV, and PDV time‐points for carotid: 0.883/0.016 vs 0.880, 0.342/0.007 vs 0.319, and 0.485/0.009 vs 0.520; suprarenal: 3.497/0.014 vs 3.500, 0.004/0.003 vs 0, and 1.656/0.073 vs 1.453; infrarenal: 4.179/0.024 vs 4.250, −1.147/0.015 vs −1.213, and 0.339/0.017 vs 0.391 L/min, respectively. The novel roller pump is suitable for benchtop testing of physiological flow. [ABSTRACT FROM AUTHOR]

Only a small number of English hospitals provide postcardiotomy venoarterial extracorporeal membrane oxygenation (VA‐ECMO) and there are doubts about its efficacy and safety. The aim of this service evaluation was to determine local survival rates and report on patient demographics. This was a retrospective service evaluation of prospectively recorded routine clinical data from a tertiary cardiothoracic center in the United Kingdom offering services including cardiac and thoracic surgery, heart and lung transplantation, venovenous extracorporeal membrane oxygenation (VV‐ECMO) for respiratory failure, and all types of mechanical circulatory support. In six years, 39 patients were supported with VA‐ECMO for refractory postcardiotomy cardiogenic shock (PCCS). We analyzed survival data and looked for associations between survival rates and patient characteristics. The intervention was venoarterial‐ECMO in patients with PCCS either following weaning from cardiopulmonary bypass or following a trial of inotropes and intra‐aortic balloon counterpulsation on the intensive care unit. 30‐day, hospital discharge, 1‐year and 2‐year survivals were 51.3%, 41%, 37.5%, and 38.5%, respectively. The median (IQR [range]) duration of support was 6 (4‐9 [1‐35]) days. Nonsurvival was associated with advanced age, shorter intensive care length of stay, and the requirement for postoperative hemofiltration. Reasonable survival rates can be achieved in selected patients who may have been expected to have a worse mortality without VA‐ECMO. We suggest postoperative VA‐ECMO should be available to all patients undergoing cardiac surgery be it in their own center or through an established pathway to a specialist center. [ABSTRACT FROM AUTHOR]

The use of extracorporeal membrane oxygenator instead of standard cardiopulmonary bypass during lung transplantation is debatable. Moreover, recently, the concept of prolonged postoperative extracorporeal membrane oxygenator (ECMO) support has been introduced in many transplant centers to prevent primary graft dysfunction (PGD) and improve early and long‐term results. The objective of this study was to review the results of our extracorporeal life support strategy during and after bilateral sequential lung transplantation (BSLT) for pulmonary artery hypertension. We review retrospectively our experience in BSLT for pulmonary artery hypertension between January 2010 and August 2018. A total of 38 patients were identified. Nine patients were transplanted using cardiopulmonary bypass (CPB), in eight cases CPB was followed by a prolonged ECMO (pECMO) support, 14 patients were transplanted on central ECMO support, and seven patients were transplanted with central ECMO support followed by a pECMO assistance. The effects of different support strategies were evaluated, in particular in‐hospital morbidity, mortality, incidence of PGD, and long‐term follow‐up. The use of CPB was associated with poor postoperative results and worse long‐term survival compared with ECMO‐supported patients. Predictive preoperative factors for the need of intraoperative CPB instead of ECMO were identified. The pECMO strategy had a favorable effect to mitigate postoperative morbidity and mortality, not only in intraoperative ECMO‐supported patients, but even in CPB‐supported cases. In our experience, ECMO may be considered as the first choice circulatory support for lung transplantation. Sometimes, in very complex cases, CBP is still necessary. The pECMO strategy is very effective to reduce incidence of PGD even in CPB‐supported patients. [ABSTRACT FROM AUTHOR]

Cardiopulmonary bypass (CPB) is often necessary for congenital cardiac surgery, but CPB can alter drug pharmacokinetic parameters resulting in underdosing. Inadequate plasma levels of antibiotics could lead to postoperative infections with increased morbidity. The influence of pediatric CPB systems on cefazolin and clindamycin plasma levels is not known. We have measured plasma levels of cefazolin and clindamycin in in vitro pediatric CPB systems. We have tested three types of CPB systems. All systems were primed and spiked with clindamycin and cefazolin. Samples were taken at different time points to measure the recovery of cefazolin and clindamycin. Linear mixed model analyses were performed to assess if drug recovery was different between the type of CPB system and sampling time point. The experiments were conducted at a tertiary university hospital. 81 samples were analyzed. There was a significant difference in the recovery over time between CPB systems for cefazolin and clindamycin (P <.001). Cefazolin recovery after 180 minutes was 106% (95% CI: 91‐123) for neonatal, 99% (95% CI: 85‐115) for infant, and 77% (95% CI: 67‐89) for pediatric systems. Clindamycin recovery after 180 minutes was 143% (95% CI: 116‐177) for neonatal, 111% (95% CI: 89‐137) for infant, and 120% (95% CI: 97‐149) for pediatric systems. Clindamycin recovery after 180 minutes compared to the theoretical concentration was 0.4% for neonatal, 1.2% for infants, and 0.6% for pediatric systems. The recovery of cefazolin was high in the neonatal and infant CPB systems and moderate in the pediatric system. We found a large discrepancy between the theoretical and measured concentrations of clindamycin in all tested CPB systems. [ABSTRACT FROM AUTHOR]

Cardiopulmonary bypass (CPB) requirement in infants presents a unique challenge because of the large prime volume‐to‐blood volume ratio. Packed red blood cells (PRBCs) tend to deteriorate with long‐term storage owing to their unphysiological composition and osmolality. Given that blood priming is inevitable in neonates, it is suggested that the metabolic load and osmolality are diminished before CPB initiation. We conducted the present study to test the hypothesis that the zero‐balance ultrafiltration (Z‐BUF) of the priming blood with 0.45% saline might be sufficient for modifying the metabolic load and osmolality and, thus, achieving a physiological state. Sixty infants with a weight below 10 kg undergoing CPB were randomly assigned either to a control group or to a Z‐BUF group and the Z‐BUF of the priming blood was performed in the latter group. Electrolytes and osmolality were measured in the priming blood. The bleeding volume, the blood transfusion rate, the length of mechanical ventilation, the length of stay in the intensive care unit (ICU), the body temperature, and renal biomarkers were compared between the 2 groups. The osmolality and the levels of potassium, sodium, glucose, chloride, and lactate in the priming blood were significantly decreased after Z‐BUF (P <.01). The Z‐BUF group showed significant reductions in postoperative blood loss; postoperative blood transfusion; time to extubation; the length of stay in the ICU; the levels of lactate, sodium, and blood urea nitrogen at 24 hours postoperatively and the body temperature at 18 hours postoperatively (P <.05). However, no statistically significant differences were found between the 2 groups regarding the body temperature and the levels of serum creatinine and blood urea nitrogen after admission to the ICU. The results of the present study demonstrated that the Z‐BUF of the priming blood could be a useful strategy in infants undergoing CPB insofar as it significantly modified the composition of the priming blood and improved the clinical outcome among our patients. [ABSTRACT FROM AUTHOR]

Simple regional cerebral perfusion (SRCP) or cerebro‐myocardial perfusion (CMP) is selectively used in one‐stage complex aortic arch malformation repair. This analysis was performed to investigate the effect of CMP and SRCP on perioperative blood product consumption, and to evaluate whether these two strategies have different effects on the clinical outcomes. A retrospective analysis of 284 children with complicated aortic malformation from January 2010 to June 2018 was performed. The overall cohort was divided into SRCP group (n = 202) and CMP group (n = 82). A comprehensive comparison of perioperative blood product consumption‐related indexes was performed. Cardiopulmonary bypass time, cardiac arrest time, cooling, and rewarming time in the CMP group were significantly shorter than those in the SRCP group (P < .05). Chest tube time was 3.82 ± 1.33 days in the SRCP group compared to 3.42 ± 0.97 days in the CMP group (P =.005). Moreover, intraoperative platelet (PLT) transfusion volume (mL/kg) and rate (%) were significantly lower in the CMP group (P <.001). Multivariate regression analysis found that intraoperative PLT transfusion was significantly negatively correlated with CMP management [OR = 0.237 (0.110‐0.507), P <.001] and CPB time was independently associated with delayed chest tube removal (>3 days) [OR = 1.010 (1.001‐1.020), P =.031]. In‐hospital mortality and early postoperative adverse events were not significantly different between the two groups. In children with on‐pump complex aortic arch surgeries, CMP is more preferable than SRCP in blood protection. However, overall prognosis was not remarkably different between these two perfusion groups. They are both safe and feasible. [ABSTRACT FROM AUTHOR]

Our aim was to explore the effect of two different priming strategies (artificial colloid only vs. artificial colloid combined with human serum albumin) on the prognosis of children weighing less than 5 kg undergoing on‐pump congenital heart disease (CHD) surgery. A total of 65 children weighing less than 5 kg who underwent on‐pump CHD surgery in our hospital from September 2016 to December 2017 were enrolled in this study. The children were randomly divided into two groups: artificial colloid priming group (AC group, n = 33) and artificial colloid combined albumin priming group (ACA group, n = 32). The primary clinical endpoint was the peri‐CPB colloid osmotic pressure (COP). Secondary clinical endpoints included perioperative blood product and hemostatic drug consumption, postoperative renal function, coagulation function, postoperative renal function, and postoperative recovery parameters. COP values were not significant in the priming system as well as peri‐CPB time points between the two groups (P > .05). Platelet consumption in the AC group was significantly lower than that in the ACA group (P < .05). There were no significant differences in the use of other blood products and hemostatic drugs as well as perioperative coagulation parameters between the two groups (P > .05). Postoperative length of stay in the AC group was significantly lower than that in the ACA group (P < .05). There were no significant differences in mortality, postoperative mechanical ventilation time, ICU time, and perioperative adverse events (including postoperative AKI) occurrences between the two groups (P > .05). In the on‐pump cardiac surgeries of patients weighing less than 5 kg, total colloidal priming would not affect peri‐CPB COP values, postoperative coagulation function, and blood products consumption. Total artificial colloidal priming strategy is feasible in low‐weight patients. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the hemodynamic properties and microemboli capture associated with different vacuum‐assisted venous drainage (VAVD) vacuum levels and venous reservoir levels in a neonatal cardiopulmonary bypass circuit. Trials were conducted in 2 parallel circuits to compare the performance of Capiox Baby RX05 oxygenator with separate AF02 arterial filter to Capiox FX05 oxygenator with integrated arterial filter. Arterial cannula flow rate to the patient was held at 500 mL/min and temperature maintained at 32°C, while VAVD vacuum levels (0 mm Hg, −15 mm Hg, −30 mm Hg, −45 mm Hg, −60 mm Hg) and venous reservoir levels (50 mL, 200 mL) were evaluated in both oxygenators. Hemodynamic parameters measuring flow, pressure, and total hemodynamic energy were made in real time using a custom‐made data acquisition system and Labview software. Nearly 10 cc bolus of air was injected into the venous line and gaseous microemboli detected using an Emboli Detection and Classification Quantifier. Diverted blood flow via the arterial filter's purge line and mean pressures increased with increasing VAVD levels (P < 0.01). Mean pressures were lower with lower venous reservoir levels and were greater in RX05 groups compared to FX05 (P < 0.01). Microemboli detected at the preoxygenator site increased with higher VAVD vacuum levels and lower venous reservoir levels (P < 0.01). The amount of microemboli captured by the FX05 oxygenator with integrated arterial filter was greater than by the RX05 oxygenator alone, although both oxygenators were able to clear microemboli before reaching the pseudo‐patient. [ABSTRACT FROM AUTHOR]

In a typical open‐heart surgery, the blood flow through the aortic cannula is a critical element of the cardiopulmonary bypass (CPB) procedure. Especially for the neonatal and pediatric CPB flow conditions, the need for small hydraulic diameter and large blood flow results confined turbulent jet flow regimes that exacerbate blood damage and platelet activation. Simultaneously, the confined jet wake leads to complex stagnation and recirculating flows that cause considerable thrombosis, blood, and endothelial cell damage through the aorta. Thus, an ideal neonatal CPB cannula should be able to generate optimal jet expansion so that sufficient cerebral perfusion is achieved through the head‐neck vessels to avoid postoperative neurological complications and developmental defects in children. To address these challenges, a formal bio‐inspired design framework is conducted to reach the desired cannula function through novel analogous biological components, first‐time in literature. Among the biological jet flow regimes studied, the ventricle filling‐jet generated through the atrio‐ventricle (AV) valves are found to be the most promising. Inspired from human AV valve shapes, 8 different novel cannula designs, considering the size constrains of neonatal and pediatric patients are built via high‐accurate micro stereo‐lithography. Using 2‐dimensional time‐resolved particle image velocimetry the turbulent jet wake characteristics are measured and compared. The proposed designs have exhibited a significant improvement as compared to standard circular cannula by around 30% reduction in maximum outflow velocity and more than 80% reduction in potential core length and spatial energy dissipation which results in a lower risk of cardiovascular and blood damage. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate whether processing residual pump blood with ultrafiltration could increase the increment of hemoglobin after residual pump blood reinfusion and evaluate its influence on plasma‐free hemoglobin (pFHb) level and postoperative renal function. Sixty adult patients undergoing elective cardiac surgery with cardiopulmonary bypass were assigned to 2 groups, based on pump blood processing strategy: ultrafiltration plus reinfusion (n = 30) or reinfusion (control; n = 30). Increment in hemoglobin and pFHb after reinfusion (ΔHgb, ΔpFHb), reinfusion volume, postoperative chest drainage volume (first 24 h), duration of mechanical ventilation, changes in serum creatinine, and prevalence of AKI were compared between the 2 groups. Higher levels of both ΔHgb and ΔpFHb were observed after reinfusion in the ultrafiltration group [ΔHgb 1.8 ± 1.1 g/dL vs. 1.2 ± 0.6 g/dL, P = 0.03, ΔpFHb 100 (0, 200) mg/L vs. 0 (−100, 0) mg/L, P = 0.03]. The reinfusion volume was lower in the ultrafiltration group [550 (325, 615) mL vs. 1000 (900, 1180) mL, P < 0.001]. No differences were found in postoperative chest drainage volume (first 24 h), duration of mechanical ventilation, changes in serum creatinine, and prevalence of AKI. Compared to the unprocessed group, ultrafiltration before reinfusion of residual pump blood improved the hemoglobin level and reduced volume loading. Despite an increase in pFHb, the processing procedure was not related to postoperative kidney injury. [ABSTRACT FROM AUTHOR]

Brain injury associated with deep hypothermic circulatory arrest (DHCA) has been recognized in patients with congenital heart diseases and those undergoing aortic arch surgeries. However, the preclinical investigation of long‐term cerebral injury and recovery mechanisms related to DHCA has been restricted to a satisfactory recovery animal model with a determined recovery time. This study aimed to evaluate the feasibility of a long‐term surviving DHCA model without blood priming in rats, in order to investigate the pathophysiology of long‐term complications in further studies. Twelve Sprague‐Dawley rats were divided into 2 groups: sham group (n = 3) and DHCA group (n = 9). The DHCA group was further assigned to the surviving time of postoperative day 2, 14, and 30 (n = 3, respectively). The entire cardiopulmonary bypass (CPB) circuit consisted of a modified reservoir, a custom‐designed small‐volume membrane oxygenator, a roller pump and a heater/cooler. A 24‐G catheter was cannulated in the branch of the left femoral artery for arterial blood pressure monitoring. Cardiopulmonary bypass was established via the right external jugular vein–right atrium and tail artery. Rats were cooled to a rectal temperature of 18°C, followed by 30 minutes of DHCA with global ischemia. After re‐warming for approximately 40 minutes, the animals were weaned from the CPB at 35.5°C. Blood gas and hemodynamic parameters were recorded preoperatively and intraoperatively, and at 2, 14, and 30 days postoperatively. Thereafter, the brains were perfusion fixed and histologically analyzed. All DHCA processes were successfully achieved, and none of the rats died. Blood gas analysis and hemodynamic parameters at each time point were normal, and vital signs of all rats were stable. Histopathologic deficits in the hippocampus (pathological score, surviving hippocampal neurons, and Ki67‐positive neurons) manifested after 30 minutes of DHCA, which persisted for at least 14 days and recovered after 30 days. A novel and simple long‐term recovery model of DHCA in rats was established in the present study, and histopathologic deficits were observed after clinically relevant 30‐minute DHCA durations, in order to determine the 30‐day recovery time frame. [ABSTRACT FROM AUTHOR]

The use of minimized cardiopulmonary bypass support to reduce the side effects of extracorporeal circulation is still contradictorily discussed. This study compares perfusion operated by conventional (CCPB) and minimized (MCPB) cardiopulmonary bypass support during coronary artery bypass grafting (CABG). This study includes the data of 5164 patients treated at our department between 2004 and 2014. Tissue perfusion during cardiopulmonary bypass support and cardiac arrest was assessed by means of body mass index, hemodilution, blood pressure with corresponding pump flow and venous oxygen saturation, serum lactate, and serum pH. Hemodilution was more pronounced after CCPB: hemoglobin had dropped to 4.47 ± 0.142 g/dL after CCPB and to 2.77 ± 0.148 g/dL after MCPB (P = 0.0022). Despite the higher pump flow in conventional circuits (4.86–4.95 L/min vs. 4.1–4.18 L/min), mean blood pressure was higher during minimized bypass support (53 ± 10 vs. 56 ± 13 mm Hg [aortic clamping], 57 ± 9 vs. 61 ± 12 mm Hg [34°C], 55 ± 9 vs.59 ± 11 mm Hg [aortic clamp removal], P < 0.0001) at all time points. Venous oxygen saturation remained on comparable levels of >70% during both conventional and minimized cardiopulmonary bypass support. The increase in serum lactate was more pronounced after CCPB (8.98 ± 1.28 vs. 3.66 ± 1.25 mg/dL, P = 0.0079), corresponding to a decrease in serum pH to acidotic levels (7.33 ± 0.06 vs. 7.35 ± 0.06, P < 0.0001). These effects were evident in all BMI ranges. Minimized cardiopulmonary bypass support provides efficient perfusion in all BMI ranges and is thus equivalent to conventional circuits. [ABSTRACT FROM AUTHOR]

Robotic surgery for intracardiac pathologies in children is relatively uncommon. This study presents our initial experience with robotic‐assisted cardiac surgery in children. We also present the feasibility and safety of robotic surgery in children. From May 2013 to June 2018, 30 children underwent totally endoscopic robotic atrial septal defect closure (n = 22), right‐sided (n = 5) or left‐sided (n = 1) partial anomalous pulmonary venous connection repair, tricuspid valve annuloplasty (n = 4), and mitral valve replacement (n = 2, due to Barlow and rheumatic diseases). The mean age of the patients was 16.1 ± 1.1 years (range, 13–17) and the mean weight was 56.7 ± 0.1 kg (range, 42–77). Associated anomalies included left persistent superior vena cava (n = 2) and the absence of innominate vein (n = 1). All procedures were completed uneventfully. Operation time was 4.1 ± 0.6 h. No patient was converted to thoracotomy or sternotomy. Cardiopulmonary bypass and aortic clamping times were 90.6 ± 28.0 (range, 45–136) and 48.6 ± 24.9 (range, 15–94) min, respectively. The mean ventilation time was 3.7 ± 1.2 h and hospital stay time was 3.3 ± 0.7 days. No right phrenic nerve injury, hemorrhage, or blood transfusion were noted. One patient had postoperative pneumothorax, and 1 had supraventricular arrhythmia. Follow‐up was a mean of 1.7 years (range, 1–52 months). Patients were healthy and no residual intracardiac defect was observed on echocardiography examinations. There was no operative or follow‐up mortality. Robotically assisted cardiac surgery is a feasible and safe approach in selected pediatric patients. In the future, new generation robotic devices may offer an alternative surgical approach in cardiac surgery for younger children with lower body weight. [ABSTRACT FROM AUTHOR]

Blood priming is needed for cardiopulmonary bypass (CPB) in neonates and infants to avoid exceeding hemodilution; however, transfusion‐related inflammation affects post‐CPB outcomes in infant open‐heart surgery. Procalcitonin, a newly detected inflammatory moderator and a sensitive parameter for predicting pulmonary dysfunction secondary to CPB, rises after CPB. We hypothesized that the hemofiltration of priming blood before CPB might decrease inflammatory mediators in the blood and post‐CPB inflammatory replications, thereby improving the respiratory function after CPB in infants. Sixty infants with a weight below 10 kg were divided randomly into two equal groups of CPB with the zero‐balance ultrafiltration (Z‐BUF) of priming blood and CPB without it. The procalcitonin level was measured before anesthesia, after admission to the intensive care unit (ICU), and 24 h afterward. The respiratory index and pulmonary compliance were measured after anesthesia, at the end of CPB, and 2 h after admission to the ICU. Additionally, time to extubation was recorded. The Z‐BUF of priming blood maintained electrolytes within a physiologic level, and procalcitonin had a slighter rise in the Z‐BUF Group at 24 h after admission to the ICU (P = 0.05). The respiratory index was decreased in the Z‐BUF Group, but the difference with the control group did not reach statistical significance (P > 0.05). The change in pulmonary compliance was significantly increased in the cyanotic patients in the intervention group, but there was no significant difference between the two groups. The time to extubation and the ICU stay were shorter in the Z‐BUF Group (P < 0.05). A positive correlation was found between the peak procalcitonin concentration and the time to extubation directly and pulmonary compliance reversely. These results suggest that the Z‐BUF of priming blood may have some beneficial clinical effects such as improved respiratory function and attenuated procalcitonin. [ABSTRACT FROM AUTHOR]

Measurement of lactate concentrations during cardiac surgery with cardiopulmonary bypass (CPB) is a reliable monitoring tool for the assessment of the adequacy of perfusion, and a predictor of poor outcome. However, increased lactate production, which is multifactorial (anaerobic metabolism, hyperglycemia), increased lactate load by packed red blood cell (PRBC) transfusions, and decreased lactate clearance may all result in hyperlactatemia. The aim of this study was to estimate the clearance of lactate in infants undergoing surgery with CPB, using the lactate load from the PRBCs transfusions received during CPB. Retrospective cohort of infants <1 year of age with repeated lactate measurements during CPB, and a known lactate concentration in the PRBCs used during CPB were evaluated. All patients received PRBCs in the prime and during CPB to maintain hematocrit >35% and venous saturation >70%. Lactate kinetics were estimated across several time intervals between two lactate measurements, using a single compartment model. The lactate load was calculated as the product: PRBC‐lactate concentration * volume. The rate of endogenous lactate production was assumed to be unchanged (maintenance of high oxygen deliveries and normoglycemia throughout CPB). Overall, 87 calculations were performed in 27 patients, then averaged per patient. The mean lactate half‐life was 12.36 min [10.67–14.06], the mean clearance was 0.09 L/min [0.06–0.11], the indexed lactate clearance was 0.36 L/min/m2 [0.28–0.44]. Lactate clearance increased significantly with age. The half‐life of lactate in infants is comparable with that reported in adults with CPB, and lactate clearance is higher. Knowing the high lactate content of PRBCs, lactate clearance rather than absolute concentration is potentially a better indicator of the adequacy of perfusion during CPB in infants. [ABSTRACT FROM AUTHOR]

The I First International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion i was held at the Hotel Hershey, Hershey, Pennsylvania, in 2005.1 Since then, we have organized 16 annual conferences nationally and internationally. We will continue to use the multi-disciplinary team approach to minimize the morbidity and mortality of underserved congenital heart surgery patients and share additional novel solutions in the future for this particular high-risk patient population. Also, the significant amount of funds from the Department of Pediatrics (Dr. Ündar's seed funds) of the Penn State College of Medicine along with Dr. Ündar's personal TIAA-CREF retirement account were used to balance the conference budgets during the past 16 years. [Extracted from the article]

An editorial is presented on the works of John H. Gibbon Jr., the surgeon and the inventor of the heart-lung machine. Topics discussed include his work related to the open cardiotomy in a human in the year 1953, his initiatives for the heart-lung machine's development, and his non-medical interests work done by him following his retirement.

Abstract: Design of contemporary oxygenators requires better understanding of the influence of hydrodynamic patterns on gas exchange. A decrease in blood path width or an increase in intraoxygenator turbulence for instance, might increase gas transfer efficiency but it will increase shear stress as well. The aim of this clinical study was to examine the association between shear stress and oxygen and carbon dioxide transfer in different contemporary oxygenators during cardiopulmonary bypass (CPB). The effect of additional parameters related to gas transfer efficiency, that is, blood flow, gas flow, sweep gas oxygen fraction (FiO2), hemoglobin concentration, the amount of hemoglobin pumped through the oxygenator per minute—Qhb, and shunt fraction were contemplated as well. Data from 50 adult patients who underwent elective CPB for coronary artery bypass grafting or aortic valve replacement were retrospectively analyzed. Data included five different oxygenator types with an integrated arterial filter. Relationships were determined using Pearson bivariate correlation analysis and scatterplots with LOESS curves. In the Capiox FX25, Fusion, Inspire 8F, Paragon, and Quadrox‐i groups, mean blood flows were 4.8 ± 0.9, 5.3 ± 0.7, 4.9 ± 0.7, 5.0 ± 0.6, and 5.7 ± 0.6 L/min, respectively. The mean O2 transfer/m2 membrane surface area was 44 ± 14, 51 ± 9, 60 ± 10, 63 ± 14, and 77 ± 18, respectively, whereas the mean CO2 transfer/m2 was 26 ± 14, 60 ± 22, 73 ± 29, 74 ± 19, and 96 ± 20, respectively. Associations between oxygen transfer/m2 and shear stress differed per oxygenator, depending on oxygenator design and the level of shear stress (r = 0.249, r = 0.562, r = 0.402, r = 0.465, and r = 0.275 for Capiox FX25, Fusion, Inspire 8F, Paragon, and Quadrox‐i, respectively, P < 0.001 for all). Similar associations were noted between CO2 transfer/m2 and shear stress (r = 0.303, r = 0.439, r = 0.540, r = 0.392, and r = 0.538 for Capiox FX25, Fusion, Inspire 8F, Paragon, and Quadrox‐i, respectively, P < 0.001 for all). In addition, O2 transfer/m2 was strongly correlated with FiO2 (r = 0.633, P < 0.001), blood flow (r = 0.529, P < 0.001), and Qhb (r = 0.589, P < 0.001). CO2 transfer/m2 in contrast was predominately correlated to sweep gas flow (r = 0.567, P < 0.001). The design‐dependent relationship between shear stress and gas transfer revealed that every oxygenator has an optimal range of blood flow and thus shear stress at which gas transfer is most efficient. Gas transfer is further affected by factors influencing the O2 or CO2 concentration gradient between the blood and the gas compartment. [ABSTRACT FROM AUTHOR]

Abstract: Physiologically, blood ejected from the left ventricle in systole exhibited spiral flow characteristics. This spiral flow has been proven to have several advantages such as lateral reduction of directed forces and thrombus formation, while it also appears to be clinically beneficial in suppressing neurological complications. In order to deliver spiral flow characteristics during cardiopulmonary bypass operation, several modifications have been made on an aortic cannula either at the internal or at the outflow tip; these modifications have proven to yield better hemodynamic performances compared to standard cannula. However, there is no modification done at the inlet part of the aortic cannula for inducing spiral flow so far. This study was carried out by attaching a spiral inducer at the inlet of an aortic cannula. Then, the hemodynamic performances of the new cannula were compared with the standard straight tip end‐hole cannula. This is achieved by modeling the cannula and attaching the cannula at a patient‐specific aorta model. Numerical approach was utilized to evaluate the hemodynamic performance, and a water jet impact experiment was used to demonstrate the jet force generated by the cannula. The new spiral flow aortic cannula has shown some improvements by reducing approximately 21% of impinging velocity near to the aortic wall, and more than 58% reduction on total force generated as compared to standard cannula. [ABSTRACT FROM AUTHOR]

Abstract: Implantation of left ventricular assist devices typically requires cardiopulmonary bypass support, which is associated with postoperative complications. A novel suture‐less inflow cannula, which can be implanted without bypass, uses mild myocardial compression to seal the interface, however, this may lead to necrosis of the myocardium. To circumvent this issue, a bilayered scaffold has been developed to promote tissue growth at the interface between cannula and myocardium. The bilayered scaffold consists of a silicone base layer, which mimics the seal, and a melt electrospun polycaprolactone scaffold to serve as a tissue integration layer. Biocompatibility of the bilayered scaffolds was assessed by analyzing cell viability, morphology, and metabolic activity of human foreskin fibroblasts cultured on the scaffolds for up to 14 days. There was no evidence of cytotoxicity and the cells adhered readily to the bilayered scaffolds, revealing a cell morphology characteristic of fibroblasts, in contrast to the low cell adhesion observed on flat silicone sheets. The rate of cell proliferation on the bilayered scaffolds rose over the 14‐day period and was significantly greater than cells seeded on the silicone sheets. This study suggests that melt electrospun bilayered scaffolds have the potential to support tissue integration of a suture‐less inflow cannula for cardiovascular applications. Furthermore, the method of fabrication described here and the application of bilayered scaffolds could also have potential uses in a diverse range of biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to compare the Capiox FX15 oxygenator with integrated arterial filter to the Capiox RX15 oxygenator with separate Capiox AF125 arterial filter in terms of hemodynamic properties and gaseous microemboli (GME) capturing. Trials were conducted at varying flow rates (2.0 L/min, 3.0 L/min, 4.0 L/min), temperatures (30°C, 35°C), and flow modalities (pulsatile, nonpulsatile). Pressure and flow waveforms were recorded using a custom‐made data acquisition system. GME data were recorded using an Emboli Detection and Classification Quantifier after injecting a 5 mL air bolus into the venous line. Maximum instantaneous pre‐oxygenator flows reached 7.4 L/min under pulsatile conditions when the roller pump was set to a flow rate of 4 L/min. Mean pressure drops were slightly greater in the FX15 group (P < 0.0001), and the diverted flow from the arterial purge line was slighter greater in the FX15 group at 3 L/min and 4 L/min (P < 0.0001). There was a slight generation of surplus hemodynamic energy (SHE) at the pre‐oxygenator site for both oxygenators under “nonpulsatile mode.” However, higher pre‐oxygenator SHE levels were recorded for both groups with “pulsatile mode.” The RX15 and FX15 groups were both able to remove all microemboli from the circuit at 2 L/min and 3 L/min in “nonpulsatile mode.” Microemboli were delivered to the patient at 4 L/min with pulsatile flows in both groups. The RX15 oxygenator with separate AF125 arterial filter and FX15 oxygenator with integrated arterial filter performed similarly in terms of hemodynamic performance and microemboli capturing. Pulsatile flows at 4 L/min produced instantaneous flow rates that surpassed the documented maximum flow rates of the oxygenators and might have contributed to the delivery of GME to the pseudo‐patient. [ABSTRACT FROM AUTHOR]

Abstract: We aimed to evaluate the timing of preoperative intra‐aortic balloon pump (IABP) placement and outcomes in patients undergoing off‐pump coronary artery bypass grafting (OPCAB). Patients with prophylactic IABP placement before OPCAB presenting between January 1, 2010 and December 31, 2013 were included. Patients were categorized into two groups based on the timing of preoperative IABP placement: less than 2 h (Group A, n = 223) and more than 2 h (Group B, n = 94). According to the European System for Cardiac Operative Risk Evaluation (EuroSCORE), patients were divided into two subgroups: middle‐low EuroSCORE (<6, Groups A1 and B1) and high EuroSCORE (≥6, Groups A2 and B2). Clinical data were compared between groups. Groups contained the following numbers of patients: Group A1, 163; Group A2, 60; Group B1, 60; and Group B2, 34. There was a significant difference in length of ICU and hospital stay between Group A and Group B, respectively (40.5 [22, 64] vs. 26.25 [18, 46.5] hours, P = 0.006; 16 [11, 22] vs. 11 [8, 14] days, P = 0.000). Duration of IABP support, ICU length of stay, hospital length of stay, and cost of hospitalization were significantly higher in Group A1 than in Group B1, respectively (73.69 ± 44.12 vs. 64.03 ± 40.93 h, P = 0.013; 36 [20, 56.5] vs. 25.5 [17, 43.75] hours, P = 0.035; 15(11,21) vs. 9(7.25, 12) days, P = 0.000; 109.53(101.20, 131.1) vs. 102.7(95.94, 115.32) thousands CNY, P = 0.009). The length of hospital stay was also significantly higher in Group A2 than in Group B2 (18(13, 26) vs. 13(11, 15) hours, P = 0.000). Preoperative placement of IABP greater than 2 h prior to OPCAB is of benefit, especially in those with high EuroSCORE. The optimal time for prophylactic IABP placement requires further study. [ABSTRACT FROM AUTHOR]

Abstract: The V entriF lo True Pulse Pump (Design Mentor, Inc., Pelham, NH, USA) is the first blood pump designed to mimic human arterial waveforms in a standard oxygenation circuit. Our aim was to demonstrate the feasibility and safety of this pump in preparation for future studies to determine possible clinical advantages. We studied four piglets (41.4–46.2 kg): three with an implanted V entriF lo pulsatile pump and one with the nonpulsatile ROTAFLOW pump (MAQUET Holding B.V. & Co. KG, Rastatt, Germany) as a control. Hemodynamics was monitored during 6‐h cardiopulmonary bypass (CPB) support and for 2 h after weaning off CPB. The V entriF lo demonstrated physiologic arterial waveforms with arterial pulse pressure of 24.6 ± 5.7 mm Hg. Pump flows (2.0 ± 0.1 L/min in ROTAFLOW; 1.9 ± 0.1 L/min in V entriF lo) and plasma free hemoglobin levels (27.9 ± 12.5 mg/dL in ROTAFLOW; 28.5 ± 14.2 mg/dL in V entriF lo) were also comparable, but systemic O2 extraction (as measured by arterial minus venous O2 saturation) registered slightly higher with the V entriF lo (63.2 ± 6.9%) than the ROTAFLOW (55.4 ± 6.5%). Histological findings showed no evidence of ischemic changes or thromboembolism. This pilot study demonstrated that the V entriF lo system generated pulsatile flow and maintained adequate perfusion of all organs during prolonged CPB. [ABSTRACT FROM AUTHOR]