Description

The prevalence of post-cardiotomy extracorporeal life support (PC-ECLS) varies between 0.6% and 3.6% of all cardiac surgical cases and represents one of the most common applications of ECLS. While a majority of patients can be weaned from cardiopulmonary bypass using inotropic and vasoactive medication, some experience refractory cardiac and/or pulmonary dysfunction requiring prolonged postoperative mechanical circulatory support. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support is a respected therapeutic option for short-term mechanical circulatory support in these critically ill patients. Indications for PC-ECLS usually include intra-operative failure to wean from cardiopulmonary bypass due to perioperative left, right or biventricular failure, or refractory cardiogenic shock/cardiac arrest in the postoperative period. While ECLS can be a life-saving therapy, it is characterized by a high mortality and morbidity due to neurologic and vascular complications amongst others.

Recently published studies reported that long-term prognosis of in-hospital survivors after ECMO support following cardiovascular surgery remains unsatisfactory, however, patients who survive have the chance to make a full recovery despite a very unfavorable prognosis without VA-ECMO. Predisposing risk factors influencing long-term survival are not fully known, however this knowledge is necessary for adequate patient selection and comprehensive decision-making prior to ECMO implantation in order to identify those patients who will truly benefit from ECMO support, since unrestrained use might disproportionately increase hospital costs and consume valuable resources.

Recently, the Extracorporeal Life Support Organization (ELSO) Registry reported a remarkable increase in the use of ECLS as a supportive therapy after cardiac surgery. However, a disappointing trend was observed with regards to the in-hospital survival rate, reaching only 15% in the latest period.

Despite this increase in use and new technological developments in this area, only a few comprehensive and dedicated reports about PC-ECLS have been presented. Nevertheless, PC-ECLS has represented the main indication for ECLS utilization and is characterized by specific aspects (duration and type of underlying disease, severity of comorbidities, indication and type of surgical procedure, modality of access and timing of implant, complication types and rates) when compared to other ECLS indication Cardiovascular diseases (CVD) are responsible for more than 4 million deaths in Europe per year. Thereby, CVD account for approximately 45% of mortality in Europe. Apart from medical and ethical aspects, this poses an economical disaster: annual costs of roughly 210 trillion USD. Among cardiovascular diseases, coronary heart disease alone is responsible for 1 million deaths per year. Myocardial infarction (MI) is often the initial manifestation of coronary heart disease, caused by myocardial ischemia and necrosis leading to an acute decrease of cardiac function. Clinically, patients in cardiogenic shock present hypotensive, unresponsive to intravenous fluid challenge and with clinical and laboratory signs of critical end organ malperfusion requiring pharmacologic and/or mechanical circulatory support.

Cardiogenic shock (CS) is the leading cause of death after myocardial infarction and occurs in 5-10% of all cases of MI. Trials such as SHOCK, IABP-SHOCK II and IMPRESS in Severe Shock all revealed a one-year mortality of approximately 50%, which reflects constant mortality rates over the last 20 years, in spite of the applied therapeutic strategies and devices.

The unacceptably high mortality and morbidity in CS is an unsolved clinical problem despite all available treatment options.

Protected PCI is the application of Mechanical Circulatory Support (MCS) during percutaneous coronary intervention in high-risk patients, meaning that in such cases MCS systems are implanted prophylactically despite hemodynamic stability to avoid deleterious complications. The overall patient condition and temporary impairment based on the acute situation of an underlying myocardial infarction or coronary ischemia, without a manifested cardiogenic shock, are potential reasons for a "prophylactic" use of MCS.

Due to the increasing complexity of procedures and patients, feasibility of such interventions is becoming more dependent on the availability of MCS, in order to guarantee hemodynamic support during revascularization. Safety and outcome of such high-risk PCIs can potentially be improved by the application of MCS and the onset of complications such as arrhythmias, hemodynamic instability and related complications during the procedure can be reduced.

In Patient without ROSC (return of spontaneous circulation) during CPR, reestablishment of circulation by emergent VA-ECLS implantation may be indicated, since eCPR is able to improve the outcome of patients after prolonged resuscitation and no-ROSC scenario.

In 2019, at the Medical University of Vienna 25 patients were treated with eCPR (approximately 9% of all CPR-patients), 20 of these patients after OHCA (out of hospital cardiac arrest). Five patients (20%) survived with a good neurologic outcome.

In the eCPR setting, time between circulatory arrest and its recovery by the ECMO circuit, is a major crucial and impacting factor as well. The ease of use in terms of device implantation would be of high importance in those cases in particular.

In summary, for every indication, devices used in ECLS require maximum reliability and must be able to generate adequate flow for full circulatory support and minimize blood trauma especially in the setting of prolonged support. Additionally, handling and monitoring should be non-complicated, the need for frequent patient transports (operating room - ICU - remote hospital facilities as required) should be taken into account. New devices should be evaluated considering these factors- next to assessment of outcome and device-related and unrelated ECLS complications.