Minimized extracorporeal circulation in non-coronary surgery

Minimally invasive extracorporeal circulation (MiECC) technology is characterized by improved biocompatibility due to closed-loop design, minimized priming, and markedly reduced artificial surface. Despite well-evidenced clinical advantages in coronary surgery, MiECC penetration in complex open-heart surgery is low. Concerns have been raised by surgeons and perfusionist regarding safety of perfusion in situations when the heart is opened and air is entering the closed system. Moreover, issues of blood and volume management are deemed impractical without having a reservoir. In the evolution of MiECC safety aspects as well as means of air and volume management have been addressed. The integration of active air removal devices, and the possibility of venting and volume buffering made MiECC suitable for valvular or even more complex surgery. However, typical clinical benefits found with MiECC in coronary artery bypass grafting (CABG) surgery, in particular blood sparing effects, were not reproducible. Air handling and blood management remain the main issues of MiECC in non-coronary surgery. With the introduction of modular (type IV) MiECC systems containing a second, accessory circuit for immediate conversion to open cardiopulmonary bypass (CPB), the last obstacles seem to be cleared away. The first reports using this latest development in MiECC technology sound promising. It is now up to the cardiac surgical community to adopt this technology and produce data helping to answer the question whether MiECC is the best perfusion strategy for all comer's cardiac surgery.

A Meta-Analysis of Miniaturized Versus Conventional Extracorporeal Circulation in Valve Surgery

The effects of miniaturized extracorporeal circulation in patients operated on for heart valve surgery are still inconsistent. We performed a meta-analysis of eight studies involving 1,011 patients to evaluate the comprehensive effects of miniaturized extracorporeal circulation. The results suggested its application significantly reduced the length of stay in the intensive care unit and total hospital stay after heart valve surgery, but no significant effects on reducing postoperative morbidity and mortality were observed. Further studies with long-term follow-up are needed to confirm our results.

Pulmonary complications of cardiopulmonary bypass

Pulmonary complications after the use of extracorporeal circulation are common, and they range from transient hypoxemia with altered gas exchange to acute respiratory distress syndrome (ARDS), with variable severity. Similar to other end-organ dysfunction after cardiac surgery with extracorporeal circulation, pulmonary complications are attributed to the inflammatory response, ischemia-reperfusion injury, and reactive oxygen species liberated as a result of cardiopulmonary bypass. Several factors common in cardiac surgery with extracorporeal circulation may worsen the risk of pulmonary complications including atelectasis, transfusion requirement, older age, heart failure, emergency surgery, and prolonged duration of bypass. There is no magic bullet to prevent or treat pulmonary complications, but supportive care with protective ventilation is important. Targets for the prevention of pulmonary complications include mechanical, surgical, and anesthetic interventions that aim to reduce the contact activation, systemic inflammatory response, leukocyte sequestration, and hemodilution associated with extracorporeal circulation.

Miniaturized extracorporeal circulation vs. off-pump coronary artery bypass grafting: What the evidence shows?

Recognition of the potentially deleterious effects of esxtracorporeal circulation led to off-pump coronary artery surgery (OPCAB) experiencing a surge in popularity in the initial decade after its conception. However, OPCAB has its own limitations and technical difficulties, such as coronary access, increased left ventricular size and reduced function, which may lead to the potential for suboptimal revascularization. As an alternative technique, miniaturized extracorporeal circulation (mECC) may provide a more controlled operative field in which the heart may be manipulated whilst minimizing the inflammatory, coagulopathic and haemodilutional effects of cardiopulmonary bypass. In this review, we outline the proposed benefits of the mECC system, discuss the pitfalls associated with mECC, and directly compare mECC to ‘off-pump’ coronary surgery for a variety of clinical and non-clinical outcomes.