Frank Born

Percutaneous extracorporeal life support for patients in therapy refractory cardiogenic shock: initial results of an interdisciplinary team

OBJECTIVES Therapy refractory cardiogenic shock is associated with dismal outcome. Percutaneous implantation of an extracorporeal life support (ECLS) system achieves immediate cardiopulmonary stabilization, sufficient end-organ perfusion and reduction of subsequent multiorgan failure (MOF). METHODS Forty-one patients undergoing percutaneous ECLS implantation for cardiogenic shock from February 2012 until August 2013 were retrospectively analysed. Mean age was 52 ± 13 years, 6 (15%) were female. Mean pH values obtained before ECLS implantation were 7.15 ± 0.24, mean lactate concentration was 11.7 ± 6.4 mmol/l. Levels obtained 6 h after ECLS implantation were 7.30 ± 0.14 and 8.7 ± 5.0 mmol/l, respectively. In 23 patients (56%) cardiogenic shock resulted from an acute coronary syndrome in 13 (32%) from cardiomyopathy, in 5 (12%) from other causes. Twenty-seven (66%) had been resuscitated, in 14 (34%) implantation was performed under ongoing cardiopulmonary resuscitation (CPR). Of note, 97% of the acute coronary syndrome patients underwent percutaneous coronary intervention (PCI) either before ECLS implantation or under ECLS support. Extracorporeal life support implantation was performed on scene (Emergency Department, Cath Lab, Intensive Care Unit) by a senior cardiac surgeon and a trained perfusionist, in 8 cases (20%) in the referring hospital. RESULTS Thirty-day mortality was 51% [21 patients, due to MOF (n = 14), cerebral complications (n = 6) and heart failure (n = 1)]. Logistic regression analysis identified 6-h pH values as an independent risk factor of 30-day mortality (P < 0.001, OR = 0.000, 95% CI 0.000-0.042). Neither CPR nor implantation under ongoing CPR resulted in significant differences. In 26 cases (63%), the ECLS system could be explanted, after mean support of 169 ± 67 h. Seven of these patients received cardiac surgery [ventricular assist device implantation (n = 4), heart transplantation (n = 1), other procedures (n = 2)]. CONCLUSIONS Due to the evolution of transportable ECLS systems and percutaneous techniques implantation on scene is feasible. Extracorporeal life support may serve as a bridge-to-decision and bridge-to-treatment device. Neurological evaluation before ventricular assist device implantation and PCI under stable conditions are possible. Despite substantial mortality, ECLS implantation in selected patients by an experienced team offers additional support to conventional therapy as well as CPR and allows survival in patients that otherwise most likely would have died. This concept has to be implemented in cardiac survival networks in the future.

When all else fails: extracorporeal life support in therapy-refractory cardiogenic shock

OBJECTIVES No guidelines for mechanical circulatory support in patients with therapy-refractory cardiogenic shock and multiorgan failure including ongoing cardiopulmonary resuscitation (CPR) exist. To achieve immediate cardiopulmonary stabilization, we established an interdisciplinary concept with on-site percutaneous extracorporeal life support (ECLS) implantation. METHODS From February 2012 to November 2014, 96 patients were deemed eligible for ECLS implantation. Establishing ECLS was successful in 87 patients (mean age 54 ± 13 years, 16% female, initial flow 4.4 ± 0.9 l/min). Aetiologies included acute coronary syndromes (n = 52, 60%), cardiomyopathies (n = 25, 29%) and other pathologies. Fifty-nine patients (68%) had been resuscitated, and in 27 (31%), implantation was performed during CPR; 11 patients (13%) were awake at implantation and 20 (23%) underwent implantation in the referring hospital. RESULTS Metabolic parameters differed in non-survivors versus survivors before ECLS implantation (pH 7.15 ± 0.23 vs. 7.27 ± 0.18, P = 0.007; lactate levels 10.90 ± 6.00 mmol/l vs. 8.79 ± 5.78 mmol/l, P = 0.091) and 6 h postimplantation (pH 7.27 ± 0.11 vs. 7.37 ± 0.11, P < 0.001; lactate levels 10.19 ± 5.52 mmol/l vs. 5.52 ± 4.17 mmol/l, P < 0.001). Altogether 44 patients could be weaned, and 9 were bridged to assist device implantation and 1 to heart transplantation. The mean time of support was 6 days, and the 30-day survival rate was 47% (n = 41). CONCLUSIONS ECLS serves as a bridge-to-decision and bridge-to-treatment device. Our interdisciplinary ECLS programme achieved acceptable survival of critically ill patients despite a substantial percentage of patients having been resuscitated and no absolute exclusion criteria. Further studies defining inclusion- and exclusion criteria might additionally improve outcome.

Extracorporeal life support and left ventricular unloading in a non-intubated patient as bridge to heart transplantation.

Introduction Veno-arterial extracorporeal life support (ECLS) is a well-established bridging therapy in patients with cardiac or pulmonary failure to maintain organ function and is frequently performed in patients who are not intubated. However, severly impaired cardiac function can occur pulmonary edemy in these patients, necessitating left ventricular unloading. Methods and Results In this study we report a 37-year old female patient with familiar dilated cardiomyopathy suffering from acute biventricular heart failure. After implantation of a peripheral ECLS, the decreased ventricular led to refractory pulmonary edema. To unload the left ventricle, an percutaneous balloon atrioseptostomy was performed without intubating the patient. The left ventricle was vented by the venous cannula resting inside the atrioseptostomy. After twelve days on ECLS, the patient underwent orthotopic heart transplantation. The postoperative course was uneventful and the patient discharged from intensive care unit four days after surgery. Conclusions In this report we present a patient in which the hybrid technique of ECLS with secondary left ventricular unloading was successfully used as a bridge to transplant therapy. This procedure may offer an alternative bridge-to-decision options in selected patients, including those that were not intubated or anaesthetized.

Extracorporeal Circulation During Lung Transplantation Procedures: A Meta-analysis

Extracorporeal circulation (ECC) is an invaluable tool in lung transplantation (lutx). More than the past years, an increasing number of centers changed their standard for intraoperative ECC from cardiopulmonary bypass (CPB) to extracorporeal membrane oxygenation (ECMO) – with differing results. This meta-analysis reviews the existing evidence. An online literature research on Medline, Embase, and PubMed has been performed. Two persons independently judged the papers using the ACROBAT-NRSI tool of the Cochrane collaboration. Meta-analyses and meta-regressions were used to determine whether veno-arterial ECMO (VA-ECMO) resulted in better outcomes compared with CPB. Six papers – all observational studies without randomization – were included in the analysis. All were considered to have serious bias caused by heparinization as co-intervention. Forest plots showed a beneficial trend of ECMO regarding blood transfusions (packed red blood cells (RBCs) with an average mean difference of −0.46 units [95% CI = −3.72, 2.80], fresh-frozen plasma with an average mean difference of −0.65 units [95% CI = −1.56, 0.25], platelets with an average mean difference of −1.72 units [95% CI = −3.67, 0.23]). Duration of ventilator support with an average mean difference of −2.86 days [95% CI = −11.43, 5.71] and intensive care unit (ICU) length of stay with an average mean difference of −4.79 days [95% CI = −8.17, −1.41] were shorter in ECMO patients. Extracorporeal membrane oxygenation treatment tended to be superior regarding 3 month mortality (odds ratio = 0.46, 95% CI = 0.21–1.02) and 1 year mortality (odds ratio = 0.65, 95% CI = 0.37–1.13). However, only the ICU length of stay reached statistical significance. Meta-regression analyses showed that heterogeneity across studies (sex, year of ECMO implementation, and underlying disease) influenced differences. These data indicate a benefit of the intraoperative use of ECMO as compared with CPB during lung transplant procedures regarding short-term outcome (ICU stay). There was no statistically significant effect regarding blood transfusion needs or long-term outcome. The superiority of ECMO in lutx patients remains to be determined in larger multi-center randomized trials.

Patient management in aortic arch surgery

Summary Aortic arch surgery requires complex patient management beyond the manual replacement of the diseased vessel. These procedures include (i) a thorough and pathologically adjusted preoperative evaluation, (ii) initiation and control of cardiopulmonary bypass, (iii) cerebral protection strategies and (iv) techniques to protect the abdominal end organs during prolonged operations. Due to the complexity of aortic arch procedures, multimodal real-time surveillance is required during all stages of the operation. Although having the patient survive the operation is the major goal, further observation is necessary because of the chronicity of the disease. This review summarizes specific aspects of patient management during and after operations requiring periods of circulatory arrest, without necessarily referring to all studies on this topic. The pros and cons of different strategies are weighed against each other, including the personal experience of the authors. A number of questions are raised without providing a ‘right’ or ‘wrong’ answer. We show that a number of different well-established strategies can result in comparable excellent long-lasting surgical results.

Diagnosis of coronary affection in patients with AADA and treatment of postcardiotomy myocardial failure using extracorporeal life support (ECLS).

BACKGROUND Myocardial ischemia due to concomitant coronary artery disease (CAD) or coronary dissection in patients with acute aortic dissection type Stanford A (AADA) is associated with myocardial failure and poor outcomes. Preoperative coronary angiography in this group of patients is still debated. The use of CT scan to diagnose coronary affection along with the establishment of high-pitched dual-spiral CT protocols are essential for improving outcomes. METHODS We retrospectively analyzed six AADA patients with heart failure who were treated using extracorporeal life support (ECLS). Options for diagnosing coronary affection and different therapeutic strategies for postcardiotomy cardiogenic shock in this patient cohort are discussed. RESULTS Retrospective review of CT images showed coronary abnormalities in 83% (n=5). Four patients (67%) underwent unplanned coronary artery bypass grafting (CABG). ECLS was instituted in 67% (n=4) due to left heart failure and in 33% (n=2) due to right heart failure. Thirty day mortality was 67% (n=4). The two patients that received ECLS for right ventricular support survived and both had undergone CABG. CONCLUSION Besides preoperative evaluation of the extent of the dissection, focus on coronary affection in CT-scans helps to triage the operative procedure. Hybrid operating rooms allow for immediate interventional and/or surgical treatment and enable for immediate control of revascularization results. The use of ECLS over other types of ventricular support systems may allow for myocardial recovery in selected cases.

The cardiotomy reservoir – a preliminary evaluation of a new cell source for cardiovascular tissue engineering

Objectives: Cell sources for cardiovascular tissue engineering (TE) are scant. However, the need for an ideal TE cardiovascular implant persists. We investigated the cardiotomy reservoir (CR) as a potential cell source that is more accessible and less ethically problematic. Methods: CR (n = 10) were removed from the bypass system after surgery. Isolation was performed using different isolation methods: blood samples were taken from the cardiopulmonary bypass and centrifuged at low density. The venous filter screen was cut out and placed into petri dishes for cultivation. The spongelike filter was removed, washed and treated in the same way as the blood samples. After cultivation, cell lines of fibroblasts (FB) and endothelial cells (EC) were obtained for analysis. The cells were seeded on polyurethane patches and analyzed via scanning electron microscopy (SEM), Life/Dead assay and immunohistochemistry. Results: No correlation between age, time of surgery and quality of cells was observed. The successful extraction of FB and was proven by positive staining results for TE-7, CD31 and vWF. Cell morphology, cytoskeleton staining and quantification of proliferation using WST-1 assay resembled the cells of the control group in all ways. The topography of a confluent and vital cell layer after cell seeding was displayed by SEM analysis, Life/Dead Assay and immunohistochemistry. The establishment of an extracellular matrix (ECM) was proven by positive staining for collagen IV, laminin, fibronectin and elastin. Conclusions: Viable FB and EC cell lines were extracted from the CR after surgery. Easy access and high availability make this cell source destined for widespread application in cardiovascular tissue engineering.

Recommendations for extracorporeal cardiopulmonary resuscitation (eCPR): consensus statement of DGIIN, DGK, DGTHG, DGfK, DGNI, DGAI, DIVI and GRC

Extracorporeal cardiopulmonary resuscitation (eCPR) may be considered as a rescue attempt for highly selected patients with refractory cardiac arrest and potentially reversible aetiology. Currently, there are no randomised, controlled studies on eCPR. Thus, prospective validated predictors of benefit and outcome are lacking. Currently, selection criteria and procedure techniques differ across hospitals and standardised algorithms are lacking. Based on expert opinion, the present consensus statement provides a first standardised treatment algorithm for eCPR.

Potential impact of oxygenators with venous air trap on air embolism in veno-arterial Extracorporeal Life Support

BACKGROUND Air embolism is a potentially fatal but underrecognized complication in Extracorporeal Life Support (ECLS). Oxygenators containing venous air traps have been developed to minimize the risk of air embolism in daily care. OBJECTIVE We reproduced air embolism as occurring via a central venous catheter in an experimental setting to test the potential of oxygenators with and without venous bubble trap (VBT) to withhold air. METHODS An in vitro ECLS circuit was created and a central venous catheter with a 3-way stopcock and a perforated male luer cap was inserted into the inflow line. Three different oxygenators with and without VBT and their capability to withhold air were examined. After 60 seconds of stable ECLS flow, the stopcock was opened towards the atmosphere for 3 minutes. Afterwards, air accumulation within the oxygenator was determined. RESULTS Comparison of the total air entrapment showed a significant superiority of the oxygenators with VBT (p < 0.001). All oxygenators were able to partly withhold macro air boli, however, the capacity of oxygenators with VBT was higher. Passing through the oxygenator resulted in a reduction of microbubbles in all cases. CONCLUSIONS Macro air emboli can be substantially reduced by usage of oxygenators that contain a VBT, whereas the capability to withhold microbubbles to a vast extent seems to depend on the intrinsic oxygenators membrane.

Herz-Lungen-Maschine

Die Herz-Lungen-Maschine (HLM) ist eine Geratekombination, die in Verbindung mit der extrakorporalen Zirkulation (EKZ) zur Durchfuhrung von Operationen am offenen Herzen und an Gefasen als Standardmethode eingesetzt wird. Die HLM ubernimmt in Verbindung mit dem EKZ-System bei offenen Herzoperationen im Wesentlichen die Pumpfunktion des Herzens, den Gasaustauschfunktion der Lunge sowie die Regelung der Bluttemperatur. Die wichtigsten Grundkomponenten einer modernen Herz-Lungen-Maschine sind Messgerate zur Online-Gas- und Blutgasanalyse, eine fahrbare Konsole, ein verstellbares Mastsystem, Blutpumpen, Steuer- und Uberwachungsgerate, ein Anzeige- und Bedienpanel, ein elektronischer oder mechanischer Gasblender, ein Vakuumkontroler, ein Narkosegasverdampfer und ein elektronisches Dokumentationssystem. HLM-Gerate werden unter Berucksichtigung der Funktionalitat, maximaler Zuverlassigkeit, sicherheitstechnischer und ergonomischen Aspekten, der Pramisse einer optimalen Benutzerfuhrung und einer intuitiv begreifbaren Bedienung konstruiert und entwickelt. Das wesentliche konstruktive Unterscheidungsmerkmal von Herz-Lungen-Maschinen ist primar die modulare oder semimodulare Bauweise.