Centrifugal Pump and Roller Pump in Adult Cardiac Surgery: A Meta-Analysis of Randomized Controlled Trials

Cardiopulmonary bypass associated acute kidney injury: better understanding and better prevention

Cardiopulmonary bypass (CPB) is a common technique in cardiac surgery but is associated with acute kidney injury (AKI), which carries considerable morbidity and mortality. In this review, we explore the range and definition of CPB-associated AKI and discuss the possible impact of different disease recognition methods on research outcomes. Furthermore, we introduce the specialized equipment and procedural intricacies associated with CPB surgeries. Based on recent research, we discuss the potential pathogenesis of AKI that may result from CPB, including compromised perfusion and oxygenation, inflammatory activation, oxidative stress, coagulopathy, hemolysis, and endothelial damage. Finally, we explore current interventions aimed at preventing and attenuating renal impairment related to CPB, and presenting these measures from three perspectives: (1) avoiding CPB to eliminate the fundamental impact on renal function; (2) optimizing CPB by adjusting equipment parameters, optimizing surgical procedures, or using improved materials to mitigate kidney damage; (3) employing pharmacological or interventional measures targeting pathogenic factors.

Hemolysis during open heart surgery in patients with hereditary spherocytosis - systematic review of the literature and case study

BACKGROUND

Due to the distinctive nature of cardiac surgery, patients suffering from hereditary spherocytosis (HS) are potentially at a high risk of perioperative complications resulting from hemolysis. Despite being the most prevalent cause of hereditary chronic hemolysis, the standards of surgical management are based solely on expert opinion.

OBJECTIVE

We analyze the risk of hemolysis in HS patients after cardiac surgery based on a systematic review of the literature. We also describe a case of a patient with hereditary spherocytosis who underwent aortic valve repair.

METHODS

This systematic review was registered in the PROSPERO international prospective register of systematic reviews (CRD42023417666) and included records from Embase, MEDLINE, Web of Science, and Google Scholar databases. The case study investigates a 38-year-old patient who underwent surgery for an aortic valve defect in mid-2022.

RESULTS

Of the 787 search results, 21 studies describing 23 cases of HS undergoing cardiac surgery were included in the final analysis. Hemolysis was diagnosed in five patients (one coronary artery bypass graft surgery, two aortic valve bioprosthesis, one ventricular septal defect closure, and one mitral valve plasty). None of the patients died in the perioperative period. Also, no significant clinical hemolysis was observed in our patient during the perioperative period.

CONCLUSIONS

The literature data show that hemolysis is not common in patients with HS undergoing various cardiac surgery techniques. The typical management of a patient with mild/moderate HS does not appear to increase the risk of significant clinical hemolysis. Commonly accepted beliefs about factors inducing hemolysis during cardiac surgery may not be fully justified and require further investigation.

Hemolysis and cardiopulmonary bypass: meta-analysis and systematic review of contributing factors

BACKGROUND

The use of cardiopulmonary bypass (CPB) is almost inevitable in cardiac surgery. However, it can cause complications, including hemolysis. Until now, there have not been any standards for reducing hemolysis from CPB. Therefore, this systematic review was conducted to determine the factors that increase or reduce hemolysis in the use of CPB.

METHODS

Keywords Earches (cardiac surgery AND cardiopulmonary bypass AND hemolysis) were done on PubMed databases and Cochrane CENTRAL from 1990-2021 for published randomized controlled trials (RCTs) that studied interventions on CPB, in cardiac surgery patients, and measured hemolysis as one of the outcomes. Studies involving patients with preoperative hematological disorders, prosthetic valves, preoperative use of intra-aortic balloon pumps and extracorporeal circulation, emergency and minimally invasive surgery are excluded RESULTS: The search yielded 64 studies that met the inclusion criteria, which involved a total of 3,434 patients. The most common surgery was coronary revascularization (75%). Out of 64 studies, 33 divided into 7 analyses. Remaining 31 studies were synthesized qualitatively. Significant decreases were found in centrifugal vs roller pumps for PFHb (p = 0.0006) and Hp (p < 0.0001) outcomes, separated vs combined suctioned blood (p = 0.003), CPB alternatives vs conventional CPB (p < 0.0001), and mini extracorporeal circulation (MiniECC) vs conventional CPB for LDH (p = 0.0008). Significant increases were found in pulsatility (p = 0.03) and vacuum-assisted venous drainage (VAVD) vs gravity-assisted venous drainage (GAVD) (p = 0.002).

CONCLUSION

The review shows that hemolysis could be caused by several factors and efforts have been made to reduce it, combining significant efforts could be beneficial. However, this review has limitations, such as heterogeneity due to no standards available for conducting CPB. Therefore, further research with standardized guidelines for CPB is needed to yield more comparable studies. Meta-analyses with more specific parameters should be done to minimize heterogeneity.

Turbulence in surgical suction heads as detected by MRI

BACKGROUND

Blood loss is common during surgical procedures, especially in open cardiac surgery. Allogenic blood transfusion is associated with increased morbidity and mortality. Blood conservation programs in cardiac surgery recommend re-transfusion of shed blood directly or after processing, as this decreases transfusion rates of allogenic blood. But aspiration of blood from the wound area is often associated with increased hemolysis, due to flow induced forces, mainly through development of turbulence.

METHODS

We evaluated magnetic resonance imaging (MRI) as a qualitative tool for detection of turbulence. MRI is sensitive to flow; this study uses velocity-compensated T1-weighted 3D MRI for turbulence detection in four geometrically different cardiotomy suction heads under comparable flow conditions (0-1250 mL/min).

RESULTS

Our standard control suction head Model A showed pronounced signs of turbulence at all flow rates measured, while turbulence was only detectable in our modified Models 1-3 at higher flow rates (Models 1 and 3) or not at all (Model 2).

CONCLUSIONS

The comparison of flow performance of surgical suction heads with different geometries via acceleration-sensitized 3D MRI revealed significant differences in turbulence development between our standard control Model A and the modified alternatives (Models 1-3). As flow conditions during measurement have been comparable, the specific geometry of the respective suction heads must have been the main factor responsible. The underlying mechanisms and causative factors can only be speculated about, but as other investigations have shown, hemolytic activity is positively associated with degree of turbulence. The turbulence data measured in this study correlate with data from other investigations about hemolysis induced by surgical suction heads. The experimental MRI technique used showed added value for further elucidating the underlying physical phenomena causing blood damage due to non-physiological flow.

Impact of mechanical stress on flexible tubing used for biomedical applications: Characterization of the damages and impact on the patient's health

Flexible tubing is a key part of a lot of medical devices used in hospital, but may be subjected to a lot of various mechanical stresses that can led to the failure or to complications for the patients. The nature and causes of these mechanical stresses were listed for peristaltic pump tubing, infusion set tubing and catheters. Their consequences in term of tubing damages and particular contamination were reported. The impact of the chemical nature of the tubing, of its size and also the impact of various parameters of the clinical acts were reviewed. Last the consequences for the patient's health were discussed.

Origins and Evolution of Extracorporeal Circulation: JACC Historical Breakthroughs in Perspective

Midway through the 20th century, direct open-heart operations were not yet a reality, awaiting safe methods to support the cardiopulmonary circulation during cardiac surgery. The scientific advancements collectively leading to safe cardiopulmonary bypass are considered some of the most impactful advances of modern medicine. Stimulated by the work of physiologists and engineers in the late 19th century, primitive pump and oxygenator designs were the forerunners of major work by DeBakey and others in roller pump design and by Gibbon in oxygenator development. Following Gibbon's historic successful closure of an atrial septal defect in 1953 with his heart-lung machine, it was left to Lillehei and Kirklin to first successfully repair large series of cardiac malformations. The history leading to these historic events and the subsequent evolution of cardiopulmonary bypass machines for short- and longer-term support is filled with engineering and surgical brilliance, daring innovations, and serendipity.

The impact of roller pump-assisted cardiotomy suction unit on hemolysis

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.

Fluid dynamics characterization and thrombogenicity assessment of a levitating centrifugal pump with different impeller designs

Technical guidelines nowadays recommend and regulate the use Computational Fluid Dynamics (CFD) to assess the performance of medical devices. CFD coupled to blood damage models has emerged as a powerful tool to evaluate the hemocompatibility of blood recirculating devices. The present study is aimed at evaluating the hydrodynamic performance and the thrombogenic potential of two prototypes of magnetically levitating centrifugal pumps. The two devices differ in the impeller configuration - 6-blades vs. 12-blades - and have been designed to be used in Cardiopulmonary Bypass (CPB) circuits during open heart surgery and in Extracorporeal Membrane Oxygenation (ECMO) to support patients with severe cardiac or respiratory failure. The pumps have been modelled using Direct Numerical Simulation coupled to Lagrangian analysis to predict platelet activation due to abnormal shear stress histories. Numerical results have been compared with experimental data in terms of head generation for different working points. Results show that the 6-blades pump has i) smaller stagnation areas, ii) lower stress levels and iii) higher strain rate, resulting in a lower thrombogenic potential, whereas the 12-blade impeller guarantees a more stable performance at high flow rates, suggesting its preferential use for more demanding applications, such as CPB.

Cardiopulmonary bypass and internal thoracic artery: Can roller or centrifugal pumps change vascular reactivity of the graft? The IPITA study: A randomized controlled clinical trial

Background

Cardiopulmonary bypass (CPB) induces a systemic inflammatory response (SIRS) and affects the organ vascular bed. Experimentally, the lack of pulsatility alters myogenic tone of resistance arteries and increases the parietal inflammatory response. The purpose of this study was to compare the vascular reactivity of the internal thoracic arteries (ITAs) due to the inflammatory response between patients undergoing coronary artery bypass grafting (CABG) under CPB with a roller pump or with a centrifugal pump.

Methods

Eighty elective male patients undergoing CABG were selected using one or two internal thoracic arteries under CPB with a roller pump (RP group) or centrifugal pump (CFP group). ITA samples were collected before starting CPB (Time 1) and before the last coronary anastomosis during aortic cross clamping (Time 2). The primary endpoint was the endothelium-dependent relaxation of ITAs investigated using wire-myography. The secondary endpoint was the parietal inflammatory response of arteries defined by the measurements of superoxide levels, leukocytes and lymphocytes rate and gene expression of inflammatory proteins using. Terminal complement complex activation (SC5b-9) and neutrophil activation (elastase) analysis were performed on arterial blood at the same times.

Results

Exposure time of ITAs to the pump flow was respectively 43.3 minutes in the RP group and 45.7 minutes in the CFP group. Acetylcholine-dependent relaxation was conserved in the two groups whatever the time. Gene expression of C3 and C4a in the artery wall decreased from Time 1 to Time 2. No oxidative stress was observed in the graft. There was no difference between the groups concerning the leukocytes and lymphocytes rate. SC5b-9 and elastase increased between Time 1 and Time 2.

Conclusion

Endothelium-dependent relaxation of the internal thoracic arteries was preserved during CPB whatever the type of pump used. The inflammatory response observed in the blood was not found in the graft wall within this time frame.

Trial registration

Name of trial study protocol: IPITA

Registration number (ClinicalTrials.gov): NCT04168853.

The effect of roller head pump on platelet deterioration during the simulated extracorporeal circulation

Roller pumping results in hemolysis and adverse effects on coagulation, but there are few reports on the influence of roller heads on platelets. Here, we evaluate the interaction between roller pumping and platelet function using a simulated extracorporeal circuit incorporating a vinyl chloride tube and roller head pump with 30 min recirculation. Platelet aggregation, platelet count, microparticle, P-selectin, Phosphatidylserine (PS) exposure and Ricinus Communis Agglutinin 1 (RCA-1) were measured before, 5, 10, 20, and 30 min after the recirculation using 100 ml of fresh human blood that had obtained from healthy volunteers (n = 9). Platelet aggregation and platelet count gradually decreased but microparticles significantly increased after the recirculation (P < 0.05). P-selectin, PS exposure and RCA-1 were measured using flow cytometry. There were no significant differences in the P-selectin and PS exposure expression during recirculation. RCA-1, a platelet apoptosis markers, significantly increased 30 min after recirculation (P < 0.05). We thus conclude that roller pumping induced platelet apoptosis and caused decreases in platelet count and aggregation after the recirculation.

Impact of Vacuum-Assisted Venous Drainage on Forward Flow in Simulated Pediatric Cardiopulmonary Bypass Circuits Utilizing a Centrifugal Arterial Pump Head

Objective

To analyze the impact of vacuum-assisted venous drainage (VAVD) on arterial pump flow in a simulated pediatric cardiopulmonary bypass circuit utilizing a centrifugal pump (CP) with an external arterial filter.

Methods

The simulation circuit consisted of a Quadrox-I Pediatric oxygenator, a Rotaflow CP (Maquet Cardiopulmonary AG, Rastatt, Germany), and a custom pediatric tubing set primed with Lactated Ringer's solution and packed red blood cells. Venous line pressure, reservoir pressure, and arterial flow were measured with VAVD turned off to record baseline values. Four other conditions were tested with progressively higher vacuum pressures (-20, -40, -60, and -80 mmHg) applied to the baseline cardiotomy pressure. An arterial filter was placed into the circuit and arterial flow was measured with the purge line in both open and closed positions. These trials were repeated at set arterial flow rates of 1500, 2000, and 2500 mL/min.

Results

The use of progressively higher vacuum caused a reduction in effective arterial flow from 1490±0.00 to 590±0.00, from 2020±0.01 to 1220±0.00, and from 2490±0.0 to 1830±0.01 mL/min. Effective forward flow decreased with increased levels of VAVD.

Conclusion

The use of VAVD reduces arterial flow when a CP is used as the main arterial pump. The reduction in the forward arterial flow increases as the vacuum level increases. The loss of forward flow is further reduced when the arterial filter purge line is kept in the recommended open position.

An independent flow probe is essential to monitor pump flow during cardiopulmonary bypass.

Hemolysis and Inflammatory Response to Extracorporeal Circulation during On-Pump CABG: Comparison between Roller and Centrifugal Pump Systems

Objective

To compare the perioperative incidence rates of hemolysis and inflammatory response in patients undergoing coronary artery bypass grafting with the two main types of cardiopulmonary bypass, centrifugal and roller pumps, and establish correlations among hemolytic and inflammatory changes.

Methods

This was a prospective, randomized trial of 60 patients assigned to either roller pump (G1, n=30) or centrifugal pump (G2, n=30) bypass. Markers of hemolysis (serum haptoglobin, lactate dehydrogenase [LDH]) and inflammation (interleukin [IL]1ß, IL-6, and TNF-α) were measured and analyzed.

Results

There was no significant between-group difference in the variables of interest. In G1, there was a positive association with IL-6 and TNF-α (P<0.01 and P<0.05, respectively). In G2, there was a positive association with LDH in the postoperative period (P<0.5). At 24h post-cardiopulmonary bypass, there were positive associations between LDH and IL-1ß (P<0.05), LDH and TNF-α (P<0.01), haptoglobin and TNF-α (P<0.05), and LDH and TNF-α (P<0.01) in G1, and between LDH and IL-6 (P<0.01), LDH and TNF-α (P<0.01), and LDH and IL-6 (P<0.01) in G2.

Conclusion

There were no significant between-group differences in markers of hemolysis or inflammation. IL-6 and TNF-α were positively associated with duration of cardiopulmonary bypass in G1, while LDH was positively associated with duration of cardiopulmonary bypass in G2. The rate of significant associations between markers of hemolysis and inflammation was higher in the roller pump group (G1).

Registration number

ReBEC (RBR-92b9dg).

Cardiopulmonary bypass: development of John Gibbon's heart-lung machine

Objective

To provide a brief review of the development of cardiopulmonary bypass.

Methods

A review of the literature on the development of extracorporeal circulation techniques, their essential role in cardiovascular surgery, and the complications associated with their use, including hemolysis and inflammation.

Results

The advancement of extracorporeal circulation techniques has played an essential role in minimizing the complications of cardiopulmonary bypass, which can range from various degrees of tissue injury to multiple organ dysfunction syndrome. Investigators have long researched the ways in which cardiopulmonary bypass may insult the human body. Potential solutions arose and laid the groundwork for development of safer postoperative care strategies.

Conclusion

Steady progress has been made in cardiopulmonary bypass in the decades since it was first conceived of by Gibbon. Despite the constant evolution of cardiopulmonary bypass techniques and attempts to minimize their complications, it is still essential that clinicians respect the particularities of each patient's physiological function.

Extracorporeal Membrane Oxygenation (ECMO)/Extracorporeal Carbon Dioxide Removal (ECCO2R)

Extracorporeal membrane oxygenation (ECMO) is a means of supporting severe pulmonary and cardiac dysfunction. It stabilizes critical derangements of oxygenation and ventilation, allowing time to diagnose, treat, and recover from the underlying cause of organ failure. The extracorporeal circuit has three main components: large-bore cannulae and circuit tubing to provide access to the native circulation, an artificial membrane lung to provide gas exchange, and an active pump to facilitate perfusion. Multiple clinical studies have evaluated this technology, the strongest evidence to date supporting its use being the Conventional Ventilation or ECMO for Severe Adult Respiratory Failure (CESAR) trial, which showed survival advantage when patients were treated with a protocol that included ECMO. Extracorporeal carbon dioxide removal (ECCO₂R) is similar in concept to ECMO, but has a lower flow rate and does not significantly oxygenate the patient. It is a primary treatment for hypercarbic respiratory failure or is an adjunct to reduce potentially injurious levels of mechanical ventilator support in hypoxemic respiratory failure. Complications are common occurrences on both types of therapy. Strong institutional commitment and a team approach are critical to successful implementation. Additional randomized trials are needed to clarify the appropriate indications and best practices for these lifesaving therapies.

First clinical use of a bioprosthetic total artificial heart: report of two cases

BACKGROUND

The development of artificial hearts in patients with end-stage heart disease have been confronted with the major issues of thromboembolism or haemorrhage. Since valvular bioprostheses are associated with a low incidence of these complications, we decided to use bioprosthetic materials in the construction of a novel artificial heart (C-TAH). We report here the device characteristics and its first clinical applications in two patients with end-stage dilated cardiomyopathy. The aim of the study was to evaluate safety and feasibility of the CARMAT TAH for patients at imminent risk of death from biventricular heart failure and not eligible for transplant.

METHODS

The C-TAH is an implantable electro-hydraulically actuated pulsatile biventricular pump. All components, batteries excepted, are embodied in a single device positioned in the pericardial sac after excision of the native ventricles. We selected patients admitted to hospital who were at imminent risk of death, having irreversible biventricular failure, and not eligible for heart transplantation, from three cardiac surgery centres in France.

FINDINGS

The C-TAH was implanted in two male patients. Patient 1, aged 76 years, had the C-TAH implantation on Dec 18, 2013; patient 2, aged 68 years, had the implantation on Aug 5, 2014. The cardiopulmonary bypass times for C-TAH implantation were 170 min for patient 1 and 157 min for patient 2. Both patients were extubated within the first 12 postoperative hours and had a rapid recovery of their respiratory and circulatory functions as well as a normal mental status. Patient 1 presented with a tamponade on day 23 requiring re-intervention. Postoperative bleeding disorders prompted anticoagulant discontinuation. The C-TAH functioned well with a cardiac output of 4·8-5·8 L/min. On day 74, the patient died due to a device failure. Autopsy did not detect any relevant thrombus formation within the bioprosthesis nor the different organs, despite a 50-day anticoagulant-free period. Patient 2 experienced a transient period of renal failure and a pericardial effusion requiring drainage, but otherwise uneventful postoperative course. He was discharged from the hospital on day 150 after surgery with a wearable system without technical assistance. After 4 months at home, the patient suffered low cardiac output. A change of C-TAH was attempted but the patient died of multiorgan failure.

INTERPRETATION

This preliminary experience could represent an important contribution to the development of total artificial hearts using bioprosthetic materials.

FUNDING

CARMAT SA.

Inverted-Takotsubo cardiomyopathy: severe refractory heart failure in poly-trauma patients saved by emergency extracorporeal life support

OBJECTIVES

The sequelae of severe poly-trauma may include myocardial dysfunction followed by acute heart failure and death. Inverted-Takotsubo cardiomyopathy (ITC) is a variant of stress cardiomyopathy, characterized by a contractile abnormality with extensive left ventricular circumferential dyskinesia or akinesia with a hyperkinetic apex. We report our experience with refractory cardiogenic shock and/or cardiac arrest, treated with extracorporeal life support.

METHODS

From June 2008 to December 2011, we treated 4 adult poly-trauma patients (3 men, 1 woman, mean age: 27.7 ± 13.5 years, mean ISS score 53.2 ± 15.9) with veno-arterial (V-A) extracorporeal life support for cardiopulmonary failure/cardiac arrest refractory to conventional treatment, due to inverted-Takotsubo cardiomyopathy. We used a miniaturized extracorporeal life support (ECLS) device.

RESULTS

ITC myocardial dysfunction appeared 15.4 ± 11.6 h after intensive care unit admission and rapidly evolved to refractory cardiopulmonary failure and cardiac arrest (within 4.8 ± 2.5 h of the onset). At ECLS, initiation median pH was 7.12 ± 0.14 (6.91-7.25), median lactate was 6.7 ± 2.8 (4-10) mmol/l and median vasoactive-inotropic score was 192.1 ± 50.6 µg/kg/min. Tissue perfusion improved significantly within 4 h on ECLS. Cardiac function improved gradually but consistently. Initial median ejection fraction was 14.2 ± 4.7% and median global longitudinal strain test was -7.4 ± 4.7. At complete cardiac recovery, they were 62.73 ± 7.8 and -18.43 ± 2.4%, respectively. After that, 2 patients survived and were sent to neurological rehabilitation before hospital discharge. In the other 2 cases, post-traumatic cerebral death occurred and they underwent organ explantation.

CONCLUSIONS

Rapid heparin-free ECLS may improve outcome in the most severe cases of poly-traumatized patients demonstrating refractory inverted-Takotsubo cardiomyopathy.

A randomised controlled trial of roller versus centrifugal cardiopulmonary bypass pumps in patients undergoing pulmonary endarterectomy

Objectives:

There is some controversy as to whether there is a benefit from the use of a centrifugal pump compared with a roller pump during cardiopulmonary bypass to facilitate cardiac surgery. We compared the two pumps, with the primary aim of determining any difference in the effects on inflammation after pulmonary endarterectomy surgery which required prolonged cardiopulmonary bypass and deep hypothermic circulatory arrest.

Methods:

Between September 2010 and July 2013, 58 elective patients undergoing pulmonary endarterectomy were included in this prospective, randomised, controlled study; 30 patients were randomly allocated to the control group, which used a roller pump, and 28 patients to the treatment group, which used a centrifugal pump. Interleukin-6, procalcitonin, C-reactive protein, thromboelastographic parameters, P-selectin, international normalised ratio, activated prothrombin time, free haemoglobin, haematocrit, red blood cell count, white blood cell count, platelet count and protein S100β were recorded during and after the procedure. We also recorded the length of intensive care unit stay, blood loss and transfusion, neurological outcomes and respiratory and renal failure.

Results:

There was a significant difference in the primary outcome measure: Interleukin-6 was significantly higher in the roller pump group (587±38 ng·l-1 vs. 327±37 ng·l-1; p<0.001) 24 hours after surgery, which we interpreted as an increased inflammatory response. This was confirmed by a significant rise in the procalcitonin level in the roller pump group 48 hours following surgery (0.79 (0.08-25.25) ng·ml-1 vs. 0.36 (0.02-5.83) ng·ml-1; p<0.05). There were, however, no significant differences in clinical outcome data.

Conclusions:

We have shown that the use of a centrifugal pump during prolonged cardiopulmonary bypass and deep hypothermic circulatory arrest is associated with a reduced inflammatory response compared to the standard roller pump. Larger multi-centre trials in this area of practice are required.

Perfusionist techniques of reducing acute kidney injury following cardiopulmonary bypass: an evidence-based review

Cardiac surgery utilizing cardiopulmonary bypass has come a long way since its introduction nearly 60 years ago. In the early days, end-organ damage was linked to contact of the blood with the extracorporeal circuit. One potential cardiac surgery complication known to result in significant morbidity and mortality is acute kidney injury (AKI). Causes of AKI are multifaceted, but most of them are associated with techniques that perfusionists employ during extracorporeal circuit management. These can cause patients to either go on dialysis or renal replacement therapy. Patients with AKI have longer lengths of stay and consume significant resources beyond those with normal kidney function. Few current evidence-based markers determine if the kidneys are adequately protected during surgery. Most relevant literature does not address perfusion-specific techniques that reduce the incidence of AKI. This paper reviews the pathophysiology of the kidney and focuses on perfusion techniques that may reduce the incidence of AKI.

Overcoming Challenges in the Management of Critical Events During Cardiopulmonary Bypass

Critical events during cardiopulmonary bypass (CPB) can challenge the most experienced perfusionists, anesthesiologists, and surgeons and can potentially lead to devastating outcomes. Much of the challenge of troubleshooting these events requires a key understanding of these situations and a well-defined strategy for early recognition and treatment. Adverse situations may be anticipated prior to going on CPB. Atherosclerosis is pervasive, and a high plaque burden may have implications in surgical technique modification and planning of CPB. Hematologic abnormalities such as cold agglutinins, antithrombin III deficiency, and hemoglobin S have been discussed with emphasis on managing complications arising from their altered pathophysiology. Jehovah’s witness patients require appropriate techniques for cell salvage to minimize blood loss. During initiation of CPB, devastating situations leading to acute hypoperfusion and multiorgan failure may be encountered in patients undergoing surgery for aortic dissection. Massive air emboli during CPB, though rare, necessitate an urgent diagnosis to detect the source and prompt management to contain catastrophic outcomes. Gaseous microemboli remain ubiquitous and continue to be a major concern for neurocognitive impairment despite our best efforts to improve techniques and refine the CPB circuit. During maintenance of CPB, adverse events reflect inability to provide optimal perfusion and can be ascribed to CPB machine malfunction or physiological aberrations. We also discuss critical events that can occur during perfusion and the need to monitor for organ perfusion in altered physiologic states emanating from hemodilution, hypothermia, and acid–base alterations.

Overview of the 2012 Food and Drug Administration circulatory system devices panel meeting on the reclassification of external counterpulsation, intra-aortic balloon pump, and non-roller-type cardiopulmonary bypass blood pump devices

The Food and Drug Administration held a Circulatory System Devices Advisory Panel meeting, December 5 and 6, 2012, to review the classification or potential reclassification of the following device types: external counterpulsation, intra-aortic balloon pump (IABP), and non-roller-type cardiopulmonary bypass blood pumps. These 3 devices are preamendment (Medical Device Amendments of 1976) class III devices. The advisory panel discussed the data and provided recommendations for reclassification of these devices. The panel recommended reclassification of ECP to class II for stable angina pectoris and to retain a class III for all other indications. For IABP, the recommendation was to reclassify IABP to class II for several indications (acute coronary syndrome, cardiac and noncardiac surgery, and heart failure complications) and remain class III for all other indications. As for non-roller type, the panel recommended that for cardiopulmonary bypass and temporary circulatory bypass, these devices should be reclassified to class II while retaining a class III device status for all other indications, including ventricular support both for hemodynamically unstable patients and for prophylactic support in high-risk percutaneous interventions.