Assad Haneya

Minimal Extracorporeal Circulation : An Alternative for On-Pump and Off-Pump Coronary Revascularization

BACKGROUND Coronary artery bypass surgery employing minimal extracorporeal circulation (MECC) was compared with standard extracorporeal circulation (ECC) and off-pump coronary artery bypass graft surgery (OPCABG) with regard to the perioperative course. METHODS From January 2004 to December 2007, 1,674 patients (n = 558 MECC, n = 558 ECC, n = 558 OPCABG) who underwent coronary bypass surgery were studied. The primary end point was in-hospital mortality; secondary end points were perioperative variables, intensive care, and in-hospital course. RESULTS Demographic data, comorbidity, and the European System for Cardiac Operative Risk Evaluation score (MECC 3.0%, ECC 3.5%, OPCABG 3.2%) were similar among the groups, but in-hospital mortality for elective and urgent/emergent patients was lower in the MECC and OPCABG groups (MECC 3.2%, OPCABG 3.7%, ECC 6.9%; p < 0.05). The number of distal anastomoses was lowest in the OPCABG group, but comparable for MECC and ECC patients. Postoperative ventilation time, release of creatinine kinase, catecholamine therapy, drainage loss, and transfusion requirements were lower in the MECC and OPCABG groups, whereas stay in the intensive care unit was shorter only in the latter (p < 0.05). CONCLUSIONS Minimal extracorporeal circulation is an easy and safe procedure for coronary artery bypass graft surgery. In selected patients, the advantages of MECC equal those of OPCABG. MECC should be considered as an alternative to OPCABG and standard ECC procedures.

Extracorporeal Circulatory Systems as a Bridge to Lung Transplantation at Remote Transplant Centers

BACKGROUND Worsening of lung function in patients awaiting lung transplantation can lead to ventilation-refractory hypoxemia or hypercapnia and respiratory acidosis. This report describes the successful use of different extracorporeal circulatory systems as a bridge to transplantation at remote centers. METHODS Between January 2003 and December 2009, we had 10 requests for implantation of extracorporeal circulatory systems (pumpless extracorporeal lung assist [PECLA] or extracorporeal membrane oxygenation [ECMO]) in patients decompensating on the waiting list to bridge to transplantation at three different transplant centers between 150 km and 570 km apart. Cannulas were inserted percutaneously with Seldingers technique. RESULTS The median patient age was 36 years (range, 24 to 53). Three patients were supported with PECLA and 7 with ECMO. The median duration of support was 23 days (range, 5 to 73). Two patients were initially provided with ECMO and then changed to PECLA after hemodynamic stabilization in the face of persisting pulmonary failure. Two patients died of multiorgan failure on ECMO while on the waiting list. One PECLA patient was successfully weaned and waiting for LTx. Before transplantation, 5 patients (4 PECLA and 1 ECMO) were successfully weaned from mechanical ventilation, and 3 PECLA patients were successfully weaned from the system. Seven patients were successfully bridged and transplanted. Five of 7 patients were discharged from the transplant centers. CONCLUSIONS This report suggests that implantation of extracorporeal circulatory systems is a safe method to bridge patients decompensating on the waiting list for transplantation. Support intervals of several weeks are possible.

Extracorporeal circulatory systems in the interhospital transfer of critically ill patients: experience of a single institution.

Background and Objectives: Critically ill patients with acute circulatory failure cannot be moved to other institutions unless stabilized by mechanical support systems. Extracorporeal heart and lung assist systems are increasingly used as a bridge to end-organ recovery or transplantation, and as an ultimate rescue tool in cardiopulmonary resuscitation. Patients and Methods: From July 2001 to April 2008, we had 38 requests for extracorporeal support for interhospital transfer carried out by the air medical service. Respiratory failure was present in 29 patients, who were provided with pumpless extracorporeal lung assist (PECLA) or veno-venous extracorporeal membrane oxygenation (ECMO). Cardiac failure dominated in 9 patients, who underwent implantation of extracorporeal life support (ECLS). Underlying diseases were acute respiratory distress syndrome in 15 patients, pneumonia in 7, prior lung transplant status in 4, cardiogenic shock in 7, and septic shock in 4. Results: All assist systems were connected via peripheral vessels by the Seldinger technique. Transport was uneventful in all cases with no technical failures. On arrival at the specialized care hospital, two patients had leg ischemia and underwent relocation of the arterial cannula. After a mean (SD) support of 5.1 (3.0) days for PECLA, 3.5 (2.9) days for ECLS, and 7.3 (5.8) days for ECMO, 60%, 66%, and 66% of patients, respectively,could be successfully weaned from the systems. Discharge rates were 45% for PECLA, 44% for ECLS, and 56% for ECMO. Conclusion: Our experience proves that minimized extracorporeal assist devices allow safe assistance of patients with isolated or combined heart and lung failure in need of interhospital transfer. Critically ill patients get a chance to reach a center of maximum medical care.

Management of anticoagulation in patients with subacute heparin-induced thrombocytopenia scheduled for heart transplantation

Anticoagulation management of patients with recent heparin-induced thrombocytopenia (HIT) requiring cardiopulmonary bypass (CPB) surgery is a serious challenge, and especially difficult in patients requiring urgent heart transplantation. As nonheparin anticoagulants during CPB bear a high risk of major bleeding, these patients are at risk of being taken off the transplant list. Short-term use of unfractionated heparin (UFH) for CPB, with restriction of UFH to the surgery itself, is safe and effective in patients with a history of HIT who test negative for antiplatelet factor 4 (PF4)/heparin antibodies. We present evidence that it is safe to expand the concept of UFH reexposure to patients with subacute HIT (ie, those patients with recent HIT in whom the platelet count has recovered but in whom anti-PF4/heparin IgG antibodies remain detectable) requiring heart transplantation, if they test negative by a sensitive functional assay using washed platelets. This can be lifesaving in patients with end-stage heart failure.

Temporary percutaneous right ventricular support using a centrifugal pump in patients with postoperative acute refractory right ventricular failure after left ventricular assist device implantation

OBJECTIVE Acute right ventricular (RV) failure is a life-threatening condition with a poor prognosis, and sometimes the use of mechanical circulatory support is inevitable. In this article, we describe our experience using a centrifugal pump as a temporary percutaneous right ventricular assist device (RVAD) in patients with postoperative acute refractory RV failure after left ventricular assist device (LVAD) implantation. METHODS We retrospectively reviewed eight consecutive patients with acute RV failure who underwent temporary percutaneous RVAD implantation using a centrifugal pump after LVAD implantation between April 2008 and February 2011. A Dacron graft was attached to the main pulmonary artery and passed through a subxiphoid exit, where the outflow cannula was inserted. The inflow cannula was percutaneously cannulated using Seldingers technique in the femoral vein. The chest was definitely closed. The technique allowed bedside removal, avoiding chest re-opening. RESULTS The median patient age was 52 years (range: 41-58). The median duration of support was 14 days (range: 12-14). RV systolic function improved; central venous pressure and mean pulmonary artery pressure decreased significantly after RVAD support. In three patients, an oxygenator was integrated into the RVAD due to impaired pulmonary function. Six patients were successfully weaned. Five patients survived to hospital discharge. Technical problems or serious complications concerning decannulation were not observed. CONCLUSION This report suggests that implantation of temporary percutaneous RVAD using a centrifugal pump is a safe alternative in the treatment of postoperative acute refractory RV failure. Ease of device implantation, weaning, explantation, and limited number of complications justify a liberal use.

First experience with the new portable extracorporeal membrane oxygenation system Cardiohelp for severe respiratory failure in adults.

Background: Over the last decade, technical improvements in extracorporeal membrane oxygenation (ECMO) equipment have reduced procedure-related complications and have made ECMO an effective option for patients with acute respiratory distress syndrome (ARDS) if conventional therapy fails. Methods: In this report, we present our early experience with the Cardiohelp, a new portable miniaturized ECMO system, in 22 consecutive patients with ARDS. All patients were placed on venovenous ECMO. Cannulas were inserted percutaneously, employing the Seldinger technique. Data were collected prospectively. Results: The median patient age was 47 years (36 to 61). Fifteen patients from regional hospitals were too unstable for conventional transport and were placed on Cardiohelp at the referring hospital and then transported to our institution. The patients were transported by ambulance (n=2) or helicopter (n=13) over a distance of 50-250 km. Cardiohelp support resulted in immediate improvement of gas exchange and highly protective ventilation. The median duration of support was 13 days (8 to 19). An exchange of the device was necessary in 9 patients. Sixteen patients (72.7%) were successfully weaned from ECMO and fifteen patients (68.2%) survived. Device-related complications were not observed. Conclusions: The compact portable ECMO device Cardiohelp is a highly effective method to secure vital gas exchange and to reduce further ventilator-induced lung injury in patients with acute respiratory failure. Crucial technical innovations and ease of device transport and implantation allow location-independent stabilization with consecutive inter-hospital transfer.

Minimized extracorporeal circulation system in coronary artery bypass surgery: a 10-year single-center experience with 2243 patients

OBJECTIVE Coronary artery bypass grafting (CABG) is the gold standard for the surgical therapy of multivessel coronary artery disease. To reduce the side effects, associated with standard extracorporeal circulation (ECC), a concept of minimal extracorporeal circulation (MECC) was devised in our center. We report on our 10-year experience with the MECC for coronary revascularization. METHODS From January 1998 to August 2009, 2243 patients underwent CABG with MECC in our center. In a retrospective observational study, we analyzed indication, preoperative patient co-morbidity, postoperative clinical course, and perioperative outcome of all patients operated on with MECC. Furthermore, the risk factors for mortality in the MECC group were assessed. RESULTS Patients showed a mean logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) of 4.5±0.1%. The mean age of the patients was 66.8±9.1 years. The overall 30-day mortality after CABG with MECC was 2.3%, ranging from 1.1% for elective to 13.0% for emergent patients and was significantly better than standard ECC. Only 15.3% (n=344) of patients with MECC required intra-operative blood transfusion. Postoperative catecholamine support, red blood cell transfusion, need for hemodialysis, release of creatinine kinase, incidence of stroke, and postoperative delirium were low after MECC revascularization. Ejection fraction below 30% (odds ratio (OR): 5.1), emergent operation (OR: 9.4), and high-dose catecholamine therapy (OR: 2.6) were associated predictors for mortality. CONCLUSION MECC until now is an established concept and has become an alternative for ECC in routine CABG in our center. The use of the MECC system is associated with low mortality and conversion rate. Excellent survival rates and low transfusion requirements in the perioperative course were achieved.

Technical Complications during Veno-Venous Extracorporeal Membrane Oxygenation and Their Relevance Predicting a System-Exchange – Retrospective Analysis of 265 Cases

Objectives Technical complications are a known hazard in veno-venous extracorporeal membrane oxygenation (vvECMO). Identifying these complications and predictive factors indicating a developing system-exchange was the goal of the study. Methods Retrospective study on prospectively collected data of technical complications including 265 adult patients (Regensburg ECMO Registry, 2009-2013) with acute respiratory failure treated with vvECMO. Alterations in blood flow resistance, gas transfer capability, hemolysis, coagulation and hemostasis parameters were evaluated in conjunction with a system-exchange in all patients with at least one exchange (n = 83). Results Values presented as median (interquartile range). Patient age was 50(36–60) years, the SOFA score 11(8–14.3) and the Murray lung injury Score 3.33(3.3–3.7). Cumulative ECMO support time 3411 days, 9(6–15) days per patient. Mechanical failure of the blood pump (n = 5), MO (n = 2) or cannula (n = 1) accounted for 10% of the exchanges. Acute clot formation within the pump head (visible clots, increase in plasma free hemoglobin (frHb), serum lactate dehydrogenase (LDH), n = 13) and MO (increase in pressure drop across the MO, n = 16) required an urgent system-exchange, of which nearly 50% could be foreseen by measuring the parameters mentioned below. Reasons for an elective system-exchange were worsening of gas transfer capability (n = 10) and device-related coagulation disorders (n = 32), either local fibrinolysis in the MO due to clot formation (increased D-dimers [DD]), decreased platelet count; n = 24), or device-induced hyperfibrinolysis (increased DD, decreased fibrinogen [FG], decreased platelet count, diffuse bleeding tendency; n = 8), which could be reversed after system-exchange. Four MOs were exchanged due to suspicion of infection. Conclusions The majority of ECMO system-exchanges could be predicted by regular inspection of the complete ECMO circuit, evaluation of gas exchange, pressure drop across the MO and laboratory parameters (DD, FG, platelets, LDH, frHb). These parameters should be monitored in the daily routine to reduce the risk of unexpected ECMO failure.

Support time-dependent outcome analysis for veno-venous extracorporeal membrane oxygenation §,§§

OBJECTIVE The majority of patients suffering from pulmonary failure refractory to mechanical ventilation require extracorporeal membrane oxygenation (ECMO) support between 1 and 2 weeks. This study was designed to evaluate differences in outcome depending on ECMO duration. METHODS A retrospective analysis on n = 127 patients requiring veno-venous (VV) ECMO support at our institution between April 2006 and March 2010 was applied. The patient population was divided into three groups according to the support duration (A: 0-10 days), 75 patients; B: 11-20 days, 32 patients; C: >21 days, (max. 67 days), 19 patients). Statistical comparisons between groups were calculated. RESULTS Mean age of all patients (♀ = 42 patients ♂=85 patients) was 48 ± 16 years (range 15-78 years). Bilateral pneumonia due to bacterial infection (n = 45 patients) or due to aspiration (n = 19 patients) was the main cause for pulmonary failure, other causes were extrapulmonary sepsis (n = 27 patients), major surgery (n = 17 patients), and severe trauma (n = 12 patients). Mean lung injury score (LIS) according to Murray was 3.4 ± 0.4, and mean sequential organ failure assessment (SOFA) score was 12.6 ± 3.7. Statistical comparisons revealed no significant difference in demographic parameters between groups. VV ECMO support immediately improved oxygenation, within 2h the PaO(2)/FiO(2) ratio rose from 80 ± 42 mm Hg to 129 ± 72 mm Hg (p = 0.001). Overall survival to discharge was 51.2%. There was a statistical difference in survival between groups (A = 59%, B = 31%, C = 52%; p = 0.029). Multivariate logistic regression analysis revealed renal failure (odds ratio (OR) 12.1; confidence interval (CI) 3.9-30.0; p < 0.001) and the use of NO (OR=5.8; CI=1.9-24.9; p=0.002) as risk factors for mortality. Complications consisted of cannula-related complications (14%), bleeding issues (13%), partial vein thrombosis of the cannulated vessels (9.5%), and pumphead failure (1.5%). CONCLUSION VV ECMO in patients suffering from severe lung failure is effective in improving gas exchange with an overall survival of higher than 50%. Prolonged need of ECMO support does not have an impact on survival.

Minimised versus conventional cardiopulmonary bypass: outcome of high-risk patients

BACKGROUND Coronary artery bypass grafting (CABG) with extracorporeal circulation (ECC) is the gold standard for surgical coronary re-vascularisation. Recently, minimised extracorporeal circulation system (MECC) has been postulated a safe and advantageous alternative for multi-vessel CABG. METHOD Between January 2004 and December 2007, 244 high-risk patients (logistic EuroScore (ES)>10%) underwent CABG in our institution. ECC was used in 139 (57%) and MECC in 105 (43%) patients. Demographic data including age (MECC: 73.4+/-7.4 years; ECC: 73.3+/-6.4 years), ES (MECC: 19.2+/-9.8%; ECC: 21.4+/-11.9%), left-ventricular ejection fraction (MECC: 45.6+/-16.1%; ECC: 43.1+/-15.3%), diabetes mellitus (MECC: 14.3%; ECC: 15.1%) and COPD (MECC: 6.7%; ECC: 7.9%) did not differ between the two groups. Preoperative end-stage renal failure was an exclusion criterion. The clinical course and serological/haematological parameters in the ECC and MECC patients were compared in a retrospective manner. RESULTS Although the numbers of distal anastomoses did not differ between the two groups (MECC: 3.0+/-0.9; ECC: 2.9+/-0.9), ECC time was significantly shorter in the MECC group (MECC: 96+/-33 min; ECC: 120+/-50 min, p<0.01). Creatinine kinase (CK) levels were significantly lower 6 h after surgery in the MECC group (MECC: 681+/-1505 U l(-1); ECC: 1086+/-1338 U l(-1), p<0.05) and the need of red blood cell transfusion was significantly less after MECC surgery (MECC: 3 [range: 1-6]; ECC: 5 [range: 2-9] p<0.05). Moreover, 30-day mortality was significantly lower in the MECC group as compared to the ECC group (MECC: 12.4%; ECC: 26.6, p<0.01). DISCUSSION MECC is a safe alternative for CABG surgery. A lower 30-day mortality, lower transfusion requirements and less renal and myocardial damage encourage the use of MECC systems, especially in high-risk patients.