Conventional versus miniaturized cardiopulmonary bypass: A systematic review and meta-analysis

Association of Anaesthetists guidelines: the use of blood components and their alternatives 2024

BACKGROUND

The administration of blood components and their alternatives can be lifesaving. Anaemia, bleeding and transfusion are all associated with poor peri-operative outcomes. Considerable changes in the approaches to optimal use of blood components and their alternatives, driven by the findings of large randomised controlled trials and improved haemovigilance, have become apparent over the past decade. The aim of these updated guidelines is to provide an evidence-based set of recommendations so that anaesthetists and peri-operative physicians might provide high-quality care.

METHODS

An expert multidisciplinary, multi-society working party conducted targeted literature reviews, followed by a three-round Delphi process to produce these guidelines.

RESULTS

We agreed on 12 key recommendations. Overall, these highlight the importance of organisational factors for safe transfusion and timely provision of blood components; the need for protocols that are targeted to different clinical contexts of major bleeding; and strategies to avoid the need for transfusion, minimise bleeding and manage anticoagulant therapy.

CONCLUSIONS

All anaesthetists involved in the care of patients at risk of major bleeding and peri-operative transfusion should be aware of the treatment options and approaches that are available to them. These contemporary guidelines aim to provide recommendations across a range of clinical situations.

Benefit of minimally invasive extracorporeal circulation on minimally invasive aortic valve replacement through right lateral mini-thoracotomy using femoral cannulation: a propensity-matched analysis

OBJECTIVES

The objective of this study was to evaluate the impact of minimally invasive extracorporeal circulation on blood transfusion and asymptomatic brain injury in comparison to conventional extracorporeal circulation in the context of minimally invasive aortic valve replacement through right lateral mini-thoracotomy surgery.

METHODS

This was a retrospective observational study. Patients who underwent isolated aortic valve replacement through right lateral mini-thoracotomy surgery were divided into two groups: the minimally invasive extracorporeal circulation group and the conventional extracorporeal circulation group. Propensity matching was employed for further analysis.

RESULTS

Of 242 patients, the minimally invasive group and conventional group comprised 166 patients and 76 patients, respectively. In the matched cohort of 71 pairs, the two groups had similar preoperative characteristics. Extracorporeal circulation time was similar between the minimally invasive and conventional groups: 113 and 115 min, respectively, as was aortic clamp time: 86 and 82 min, respectively. Estimated amount of haemodilution was lower in the minimally invasive group (16.8 vs. 18.8%, P = 0.006). Blood transfusion frequency during surgery was less than half of conventional in the minimally invasive group (12.7 vs. 31.0%, P = 0.01). There were no deaths or stroke in either group during the hospital stay. Asymptomatic brain injury rate was the same for the two groups (35.2 vs. 35.2%, P = 1.00).

CONCLUSIONS

Minimally invasive extracorporeal circulation was associated with fewer patients requiring transfusion than conventional extracorporeal circulation without an increase of asymptomatic brain injury in minimally invasive aortic valve replacement through right lateral mini-thoracotomy surgery.

Enhancing lung transplantation with ECMO: a comprehensive review of mechanisms, outcomes, and future considerations

BACKGROUND

Lung transplantation (LTx) is a critical intervention for patients with end-stage lung disease. However, challenges such as donor organ scarcity and post-transplant complications significantly affect its success. Recent advancements in Extracorporeal Membrane Oxygenation (ECMO) have shown promise in improving the outcomes and expanding eligibility for LTx.

METHODS

A comprehensive literature review was conducted, focusing on studies that explore the use of ECMO in lung transplantation. A thorough search of relevant studies on ECMO and LTx was conducted using multiple scholarly databases and relevant keywords, resulting in 73 studies that met the inclusion criteria. Sources included peer-reviewed journals and clinical trial results, with emphasis on articles captured recent advancements in ECMO technology and techniques.

RESULTS

ECMO has been crucial in supporting patients before, during, and after LTx. It serves as a bridge to transplantation by maintaining pulmonary and circulatory stability in critically ill patients awaiting donor organs. ECMO also aids in the evaluation of marginal donor lungs and supports patients through acute post-transplant complications. Recent technological advancements have improved the safety and efficacy of ECMO, further solidifying its role in LTx.

CONCLUSION

In conclusion, this review underscores ECMO's critical role in enhancing outcomes across all stages of lung transplantation. Its various configurations and strategies have shown promise in stabilizing critically ill patients and improving transplant success rates. Looking ahead, it's important to gather more information about the long-term outcomes and potential complications associated with ECMO use. More research and data collection will help us understand the benefits and risks better, leading to improved decision-making and patient care in this field.

Comparable bleeding and inflammation outcomes between heparin-coated and uncoated minimal invasive extracorporeal circuits in isolated coronary artery bypass surgery - A double-blinded randomized control trial

OBJECTIVE

Minimally invasive extracorporeal circulation has been shown to be non-inferior or even superior to conventional cardiopulmonary bypass circuits in isolated coronary artery bypass grafting, but there is little evidence whether the addition of a heparin-coated circuit can further reduce the inflammatory response and amount of bleeding in these patients.

METHODS

A single-center randomized control trial enrolled 49 adult patients scheduled to undergo isolated coronary artery bypass grafting with minimally invasive extracorporeal circulation (MiECC) between January 2015 and December 2018. Patients were randomized 1:1 to either the heparin-coated circuit group, or the uncoated (control) circuit group. The primary outcome was chest tube output 18 h after weaning from MiECC, and secondary outcomes included inflammatory (TNF-α, IL-6, IL-8, IL-10) and complement (C3a, C4d, C5a, sC5b-9) biomarkers, platelet count and function (D2D, TAT, SDC1, PF4), number of transfused blood products, and 30-day survival.

RESULTS

Patients were randomized to undergo myocardial revascularization using heparin-coated circuits (n = 25), and to the uncoated MiECC circuit (n = 24), with comparable baseline demographics. No significant difference was observed in chest tube output and for all secondary outcomes. IL-6 and IL-8 were increased from baseline at 18 h after weaning (effect size 0.29 and 0.05, respectively) and sC5b-9 was lower (effect size 0.11) in the heparin-coated than in the uncoated MiECC, although not significantly different.

CONCLUSIONS

Compared with an uncoated MiECC circuit, heparin-coated MiECC circuit was not associated with a reduction in postoperative bleeding, transfusion, inflammation, complement activation, and platelet biomarkers, following isolated coronary artery bypass grafting.

Minimally invasive extracorporeal circulation versus conventional cardiopulmonary bypass in patients undergoing cardiac surgery (MiECS): Rationale and design of a multicentre randomised trial

INTRODUCTION

The ultimate answer to the question whether minimal invasive extracorporeal circulation (MiECC) represents the optimal perfusion technique in contemporary clinical practice remains elusive. The present study is a real-world study that focuses on specific perfusion-related clinical outcomes after cardiac surgery that could potentially be favourably affected by MiECC and thereby influence the future clinical practice.

METHODS

The MiECS study is an international, multi-centre, two-arm randomized controlled trial. Patients undergoing elective or urgent coronary artery bypass grafting (CABG), aortic valve replacement (AVR) or combined procedure (CABG + AVR) using extracorporeal circulation will be randomized to MiECC or contemporary conventional cardiopulmonary bypass (cCPB). Use of optimized conventional circuits as controls is acceptable. The study design includes a range of features to prevent bias and is registered at clinicaltrials.gov (NCT05487612).

RESULTS

The primary outcome is a composite of postoperative serious adverse events that could be related to perfusion technique occurring up to 30 days postoperatively. Secondary outcomes include use of blood products, ICU and hospital length of stay (30 days) as well as health-related quality of life (30 and 90 days).

CONCLUSIONS

The MiECS trial has been designed to overcome perceived limitation of previous trials of MiECC. Results of the proposed study could affect current perfusion practice towards advancement of patient care.

Conventional versus minimally invasive extra-corporeal circulation in patients undergoing cardiac surgery: A randomized controlled trial (COMICS)

INTRODUCTION

The trial hypothesized that minimally invasive extra-corporeal circulation (MiECC) reduces the risk of serious adverse events (SAEs) after cardiac surgery operations requiring extra-corporeal circulation without circulatory arrest.

METHODS

This is a multicentre, international randomized controlled trial across fourteen cardiac surgery centres including patients aged ≥18 and <85 years undergoing elective or urgent isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR) surgery, or CABG + AVR surgery. Participants were randomized to MiECC or conventional extra-corporeal circulation (CECC), stratified by centre and operation. The primary outcome was a composite of 12 post-operative SAEs up to 30 days after surgery, the risk of which MiECC was hypothesized to reduce. Secondary outcomes comprised: other SAEs; all-cause mortality; transfusion of blood products; time to discharge from intensive care and hospital; health-related quality-of-life. Analyses were performed on a modified intention-to-treat basis.

RESULTS

The trial terminated early due to the COVID-19 pandemic; 1071 participants (896 isolated CABG, 97 isolated AVR, 69 CABG + AVR) with median age 66 years and median EuroSCORE II 1.24 were randomized (535 to MiECC, 536 to CECC). Twenty-six participants withdrew after randomization, 22 before and four after intervention. Fifty of 517 (9.7%) randomized to MiECC and 69/522 (13.2%) randomized to CECC group experienced the primary outcome (risk ratio = 0.732, 95% confidence interval (95% CI) = 0.556 to 0.962, p = 0.025). The risk of any SAE not contributing to the primary outcome was similarly reduced (risk ratio = 0.791, 95% CI 0.530 to 1.179, p = 0.250).

CONCLUSIONS

MiECC reduces the relative risk of primary outcome events by about 25%. The risk of other SAEs was similarly reduced. Because the trial terminated early without achieving the target sample size, these potential benefits of MiECC are uncertain.

Comparison of minimal invasive extracorporeal circulation versus standard cardiopulmonary bypass systems on coronary artery bypass surgery

Background

In this study, we shared our experience with the minimal invasive extracorporeal circulation system for coronary artery bypass grafting patients.

Methods

A total of 163 patients were included in the retrospective study, with 83 patients (63 males, 20 females; mean age: 61.9±8.9 years; range, 35 to 81 years) undergoing coronary artery bypass grafting with minimal invasive extracorporeal circulation and 80 patients (65 males, 15 females; mean age: 60.5±8.8 years; range, 43 to 82 years) undergoing coronary artery bypass grafting with conventional cardiopulmonary bypass between July 2021 and April 2023. Elective coronary bypass performed by same surgical team were included in the study. Mortality, major adverse cardiac and cerebrovascular event, hospital stays and transfusion requirements were evaluated.

Results

There were no significant differences in sex distribution, age, comorbidities, and blood values between the two groups. Intraoperatively, the minimal invasive extracorporeal circulation group had a slightly higher number of distal anastomoses and comparable times for aortic cross-clamp and cardiopulmonary bypass. Postoperative outcomes such as tamponade, bleeding, atrial fibrillation, left ventricular ejection fraction improvement or reduction, and postoperative drainage were similar between the two groups. However, the minimal invasive extracorporeal circulation group had fewer transfusions of packed red blood cells and fresh frozen plasma and a shorter length of stay in the intensive care unit.

Conclusion

The minimal invasive extracorporeal circulation system effectively preserves blood, works with lower activated clotting time values without additional complications in coronary artery bypass grafting, and could present a better option for patients with anemia or patients with a relatively high risk for high-dose heparinization.

Alterations to Kidney Physiology during Cardiopulmonary Bypass-A Narrative Review of the Literature and Practical Remarks

INTRODUCTION

According to different authors, cardiac surgery-associated acute kidney injury (CSA-AKI) incidence can be as high as 20-50%. This complication increases postoperative morbidity and mortality and impairs long-term kidney function in some patients. This review aims to summarize current knowledge regarding alterations to renal physiology during cardiopulmonary bypass (CPB) and to discuss possible nephroprotective strategies for cardiac surgeries. Relevant sections: Systemic and renal circulation, Vasoactive drugs, Fluid balance and Osmotic regulation and Inflammatory response.

CONCLUSIONS

Considering the available scientific evidence, it is concluded that adequate kidney perfusion and fluid balance are the most critical factors determining postoperative kidney function. By adequate perfusion, one should understand perfusion with proper oxygen delivery and sufficient perfusion pressure. Maintaining the fluid balance is imperative for a normal kidney filtration process, which is essential for preserving the intra- and postoperative kidney function.

FUTURE DIRECTIONS

The review of the available literature regarding kidney function during cardiac surgery revealed a need for a more holistic approach to this subject.

Biochemical Changes in Cardiopulmonary Bypass in Cardiac Surgery: New Insights

Patients undergoing coronary revascularization with extracorporeal circulation or cardiopulmonary bypass (CPB) may develop several biochemical changes in the microcirculation that lead to a systemic inflammatory response. Surgical incision, post-CPB reperfusion injury and blood contact with non-endothelial membranes can activate inflammatory signaling pathways that lead to the production and activation of inflammatory cells, with cytokine production and oxidative stress. This inflammatory storm can cause damage to vital organs, especially the heart, and thus lead to complications in the postoperative period. In addition to the organic pathophysiology during and after the period of exposure to extracorporeal circulation, this review addresses new perspectives for intraoperative treatment and management that may lead to a reduction in this inflammatory storm and thereby improve the prognosis and possibly reduce the mortality of these patients.

2021 MiECTiS focused update on the 2016 position paper for the use of minimal invasive extracorporeal circulation in cardiac surgery

The landmark 2016 Minimal Invasive Extracorporeal Technologies International Society (MiECTiS) position paper promoted the creation of a common language between cardiac surgeons, anesthesiologists and perfusionists which led to the development of a stable framework that paved the way for the advancement of minimal invasive perfusion and related technologies. The current expert consensus document offers an update in areas for which new evidence has emerged. In the light of published literature, modular minimal invasive extracorporeal circulation (MiECC) has been established as a safe and effective perfusion technique that increases biocompatibility and ultimately ensures perfusion safety in all adult cardiac surgical procedures, including re-operations, aortic arch and emergency surgery. Moreover, it was recognized that incorporation of MiECC strategies advances minimal invasive cardiac surgery (MICS) by combining reduced surgical trauma with minimal physiologic derangements. Minimal Invasive Extracorporeal Technologies International Society considers MiECC as a physiologically-based multidisciplinary strategy for performing cardiac surgery that is associated with significant evidence-based clinical benefit that has accrued over the years. Widespread adoption of this technology is thus strongly advocated to obtain additional healthcare benefit while advancing patient care.

Effect of different coronary artery revascularization procedures on cognition: A systematic review

Coronary revascularization interventions have been associated with post-intervention cognitive decline. Hence, this systematic review aims to compare the long-term effects of different coronary revascularization interventions on cognition. The Cochrane Library and MEDLINE databases were searched for articles published between January 2009 and January 2023. Articles on clinical trials and cohort studies that compared at least two different interventions with a minimum three months follow up were included to evaluate the consequences of different intervention techniques on cognition. Each selected study was evaluated using a revised tool to assess the risk of bias in randomized trials (RoB 2), and Risk of Bias In Non-Randomized Studies - of Interventions(ROBINS-1) was used for evaluating non-randomized studies. Five eligible studies, with four different comparisons, were included. Out of these studies, three RCTs and two cohort studies were included A participants gone through different procedures; on-pump and off-pump coronary artery bypass grafting (CABG), Percutaneous coronary intervention (PCI conventional cardiopulmonary bypass (CCPB), the miniaturized cardiopulmonary bypass (MCPB) and endoscopic coronary artery bypass grafting (Endo-CABG). These comparisons showed that different interventions have different effects on cognition; however, there is no solid evidence of correlations between them. Thus, the results of this review suggest that there should be greater focus on comparing interventions and that a reasonable follow-up duration should be set to avoid the influence of confounders. There is also a need to determine the effect of long-term cognitive decline while reducing interference by other variables.