The impact of haemodilution and bypass pump flow on cerebral oxygen desaturation during cardiopulmonary bypass--A comparison of two systems of cardiopulmonary bypass

Comparison of postoperative cognitive decline in patients undergoing conventional vs miniaturized cardiopulmonary bypass: A randomized, controlled trial

Background:

Neurocognitive dysfunction is a common complication of coronary artery bypass grafting (CABG) with incidence of 19–38%. The miniaturized cardiopulmonary bypass (MCPB) system was developed to reduce hemodilution and inflammation and provides better cerebral protection than conventional cardiopulmonary bypass (CCPB). In a meta-analysis, MCPB was associated with a 10-fold reduction in the incidence of strokes. However, its effect on postoperative cognitive decline (POCD) is unknown. We assessed if MCPB decreases POCD after CABG and compared the risk factors.

Methods:

A total of 71 Asian patients presenting for elective CABG at a tertiary center were enrolled. They were randomly assigned to MCPB (n = 36) or CCPB group (n = 35) and followed up in a single-blinded, prospective, randomized controlled trial. The primary outcome was POCD as measured by the repeatable battery of neuropsychological status (RBANS). Inflammatory markers (tumor necrosis factor-alpha and interleukin-6), hematocrit levels, and neutron-specific enolase (NSE) levels were studied.

Results:

Overall, the incidence of POCD at 3 months was 50%, and this was not significantly different between both groups (51.4 vs 50.0%, P = 0.90). Having <6 years of formal education [risk ratio (RR) = 3.014, 95% confidence interval (CI) = 1.054–8.618, P = 0.040] was significantly associated with POCD in the CCPB group, while the lowest hematocrit during cardiopulmonary bypass was independently associated with POCD in the MCPB group (RR = 0.931, 95% CI = 0.868–0.998, P = 0.044). The postoperative inflammatory markers and NSE levels were similar between the two groups.

Conclusions:

This study shows that the MCPB was not superior to CCPB with cell salvage and biocompatible tubing with regard to the neurocognitive outcomes measured by the RBANS.

Is there really a benefit of using minimized cardiopulmonary bypass in CABG? A retrospective propensity score-matched study with 5000 cases

The concept of minimized cardiopulmonary bypass targets at reduction of adverse effects triggered by extracorporeal circulation. In this study, benefits of minimized bypass in CABG were evaluated under particular consideration of patient body mass index and surgeon impact. From 2004 to 2014, 5164 patients underwent coronary bypass surgery (CABG). Conventional cardiopulmonary bypass (CCPB) was used in 2376 patients, minimized cardiopulmonary bypass (MCPB) in 2788 cases. Multivariate regression models were used in the entire cohort and in a propensity score-matched subgroup after expert CABG to figure out clinical differences such as mortality, postoperative renal function, and thromboembolic events. Overall mortality was 1.5% (n = 41) in the MCPB group and 3.5% (n = 82) in CCPB patients (p < 0.001). Postoperative renal failure and hemodialysis occurred in 2.6% (n = 72/MCPB) vs. 5.3% (n = 122/CCPB (p < 0.001). Multivariable regression revealed use of CCPB as risk factor for increased mortality (OR 2.01, p = 0.001), renal failure (OR 1.79, p < 0.001), and myocardial infarction (OR 1.98, p < 0.001) comparable to risk factors such as preoperative ventilation (OR 2.26, p = 0.048), diabetes mellitus (OR 1.68, p = 0.001), and cardiogenic shock (OR 3.81, p = 0.002). Body mass index had no effect on the analyzed outcome parameters (OR 0.92, p = 0.002). Propensity score-matching analysis of an expert CABG subgroup revealed CCPB as risk factor for mortality (OR 2.26, p = 0.004) and postoperative hemodialysis (OR 1.74, p = 0.017). Compared to conventional circuits, minimized bypass use in CABG is associated with lower mortality and less postoperative renal failure. A high body mass index is feasible and not a risk factor for MCPB surgery.

Mini-extracorporeal circulation technology, conventional bypass and prime displacement in isolated coronary and aortic valve surgery: a propensity-matched in-hospital and survival analysis

OBJECTIVES

Conventional cardiopulmonary bypass is the most commonly used means of artificial circulation in cardiac surgery. However, it suffers from the effects of haemodilution and activation of inflammatory/coagulation cascades. Prime displacement (PD) can offset haemodilution and mini-extracorporeal technology (MIECT) can offset both. So far, no study has compared all of these modalities together; hence, we compared the outcomes of these 3 modalities at our institution.

METHODS

This was a retrospective analysis of our cardiac surgical database. A total of 9626 patients underwent conventional bypass (CB), 3125 patients underwent a modification of CB, called PD, and 904 underwent MIECT. A 1:1 propensity-matching algorithm was employed using IBM SPSS 24 to match (i) 813 MIECT patients with 813 CB patients and (ii) 717 MIECT patients with 717 PD patients. The patients included coronary artery bypass grafting and valve surgery.

RESULTS

MIECT had significantly (P < 0.05) longer bypass and cross-clamp times compared to CB and PD. MIECT had significantly higher rates of postoperative atrial fibrillation associated with it compared to CB. The mean red cell blood transfusion was significantly lower in the MIECT group compared to the CB group as was the mean platelet transfusion and fresh frozen plasma transfusion. The overall 5-year survival was higher in the MIECT group compared to the CB group (log-rank, P = 0.018). Between the MIECT and the PD groups, we found the incidence of renal failure and gastrointestinal complications to be significantly higher in the PD group compared to the MIECT group.

CONCLUSIONS

MIECT has short-term advantages over CB and PD. However, due to the retrospective limitations of the study, including calendar time bias, a multicentre randomized controlled trial comparing all 3 modalities will be beneficial for the larger cardiac community.

Near-infrared spectrometry in pregnancy: progress and perspectives, a review of literature

Near-infrared spectroscopy (NIRS) allows continuous noninvasive monitoring of in vivo oxygenation in selected tissues. It has been used primarily as a research tool for several years, but it is seeing wider application in the clinical arena all over the world. It was recently used to monitor brain circulation in cardiac surgery, carotid endarteriectomy, neurosurgery and robotic surgery. According to the few studies used NIRS in pregnancy, it may be helpful to assess the impact of severe forms of preeclampsia on brain circulation, to evaluate the efficacy of different treatments. It may also be used during cesarean section to detect earlier sudden complications. The evaluation of placental function via abdominal maternal approach to detect fetal growth restriction is a new field of application of NIRS.

Use of minimal invasive extracorporeal circulation in cardiac surgery: principles, definitions and potential benefits. A position paper from the Minimal invasive Extra-Corporeal Technologies international Society (MiECTiS)

Minimal invasive extracorporeal circulation (MiECC) systems have initiated important efforts within science and technology to further improve the biocompatibility of cardiopulmonary bypass components to minimize the adverse effects and improve end-organ protection. The Minimal invasive Extra-Corporeal Technologies international Society was founded to create an international forum for the exchange of ideas on clinical application and research of minimal invasive extracorporeal circulation technology. The present work is a consensus document developed to standardize the terminology and the definition of minimal invasive extracorporeal circulation technology as well as to provide recommendations for the clinical practice. The goal of this manuscript is to promote the use of MiECC systems into clinical practice as a multidisciplinary strategy involving cardiac surgeons, anaesthesiologists and perfusionists.