Extracorporeal Membrane Oxygenation System Research Articles

Management of Circuit Air in Extracorporeal Membrane Oxygenation: A Single Center Experience.

Air in circuit in patients receiving extracorporeal membrane oxygenation (ECMO) is an emergency. Different protocols have been suggested to deal with this rare but fatal complication, but their efficacies are rarely reported. We report our institutions' experience in the management of circuit air in Cardiohelp HLS ECMO system. Between October 2009 and July 2020, 4 out of 116 patients developed gas bubbles in ECMO circuit or systemic gas embolism. The clinical characteristics of these patients, source of air, presence of arterial air or pump airlock, cardiorespiratory status during the event, techniques employed to re-establish flow, ECMO downtime, neurologic, and other clinical outcomes were reported. In all cases, the source of air was located, with three of them being on the venous side of the circuit. Centrifugal pump airlock with cessation of ECMO flow was reported in two patients. Strategies used to re-establish ECMO flow included circuit change or deairing using backflush technique. All patients were weaned from ECMO, and three of them were discharged from hospital alive. With effective management, systemic gas embolism could be avoided during air in circuit emergencies. Backflush technique is a safe and effective deairing method to overcome centrifugal pump airlock in Cardiohelp HLS system.

Extracorporeal Membrane Oxygenation (ECMO) System for Respiratory and Circulatory Support

Extracorporeal membrane oxygenation (ECMO) is a respiratory or cardiac life support consisting of a vascular access cannula, a blood pump, and an artificial lung that removes carbon dioxide and adds oxygen. Venovenous ECMO is typically used for various forms of critical respiratory failure including severe pneumonia due to the new coronavirus, whereas venoarterial (VA) ECMO sees greater utilization in the patient with heart failure such as cardiac arrest or other clinical states in which cardiac dysfunction is a significant component of illness. The transference of gases occurs due to diffusion across the hollow fiber membranes packed in the module of the oxygenator. Emergence of microporous membrane tremendously enhanced gas diffusion, and currently microporous membrane with a dense layer on the blood-contacting surface is widely used for longer period of usage over weeks. As the usage period for respiratory failure is getting longer, development of more durable ECMO system is required in the future.

Platelet count reduction during in vitro membrane oxygenation affects platelet activation, neutrophil extracellular trap formation and clot stability, but does not prevent clotting.

Introduction:Due to improved technology and increased application the mortality during extracorporeal membrane oxygenation (ECMO) is constantly declining. Nevertheless, complications including haemorrhage or thrombus formation remain frequent. Local mitigation of coagulation within an ECMO system to prevent thrombus formation on ECMO components and optimizing systemic anticoagulation is an approach to reduce clotting and bleeding complications at once. Foreign surfaces of ECMO systems, activate platelets (PLTs), which besides their major role in coagulation, can trigger the formation of neutrophil extracellular traps (NETs) contributing to robust thrombus formation. The impact of a reduced PLT count on PLT activation and NET formation is of paramount importance and worth investigating.Methods:In this study platelet poor (PLT–) and native (PLT+) heparinized human blood was circulated in two identical in vitro test circuits for ECMO devices for 6 hours. PLT reduction was achieved by a centrifugation protocol prior to the experiments. To achieve native coagulation characteristics within the test circuits, the initial heparin dose was antagonized by continuous protamine administration.Results:The PLT– group showed significantly lower platelet activation, basal NET formation and limited clot stability measured via thromboelastometry. Fluorescent and scanning electron microscope imaging showed differences in clot composition. Both groups showed equal clot formation within the circuit.Conclusions:This study demonstrated that the reduction of PLTs within an ECMO system is associated with limited PLT activation and NET formation, which reduces clot stability but is not sufficient to inhibit clot formation per se.

Autopsy findings after long-term treatment of COVID-19 patients with microbiological correlation

Between April and June 2020, i.e., during the first wave of pandemic coronavirus disease 2019 (COVID-19), 55 patients underwent long-term treatment in the intensive care unit at the University Hospital of Regensburg. Most of them were transferred from smaller hospitals, often due to the need for an extracorporeal membrane oxygenation system. Autopsy was performed in 8/17 COVID-19-proven patients after long-term treatment (mean: 33.6 days). Autopsy revealed that the typical pathological changes occurring during the early stages of the disease (e.g., thrombosis, endothelitis, capillaritis) are less prevalent at this stage, while severe diffuse alveolar damage and especially coinfection with different fungal species were the most conspicuous finding. In addition, signs of macrophage activation syndrome was detected in 7 of 8 patients. Thus, fungal infections were a leading cause of death in our cohort of severely ill patients and may alter clinical management of patients, particularly in long-term periods of treatment.

Extracorporeal Membrane Oxygenation for COVID-19 Respiratory Distress Syndrome: An Italian Society for Cardiac Surgery Report.

An increased need of extracorporeal membrane oxygenation (ECMO) support is going to become evident as treatment of SARS-CoV-2 respiratory distress syndrome. This is the first report of the Italian Society for Cardiac Surgery (SICCH) on preliminary experience with COVID-19 patients receiving ECMO support. Data from 12 Italian hospitals participating in SICCH were retrospectively analyzed. Between March 1 and September 15, 2020, a veno-venous (VV) ECMO system was installed in 67 patients (94%) and a veno-arterio-venous ECMO in four (6%). Five patients required VA ECMO after initial weaning from VV ECMO. Thirty (42.2%) patients were weaned from ECMO, while 39 (54.9%) died on ECMO, and six (8.5%) died after ECMO removal. Overall hospital survival was 36.6% (n = 26). Main causes of death were multiple organ failure (n = 14, 31.1%) and sepsis (n = 11, 24.4%). On multivariable analysis, predictors of death while on ECMO support were older age (p = 0.048), elevated pre-ECMO C-reactive protein level (p = 0.048), higher positive end-expiratory pressure on ventilator (p = 0.036) and lower lung compliance (p = 0.032). If the conservative treatment is not effective, ECMO support might be considered as life-saving rescue therapy for COVID-19 refractory respiratory failure. However warm caution and thoughtful approaches for timely detection and treatment should be taken for such a delicate patients population.

Analysis of extracorporeal membrane oxygenation in trauma patients with acute respiratory distress syndrome: A case series.

Thoracic trauma is the most common injury in polytrauma patients. Often associated with the development of an acute respiratory distress syndrome (ARDS), conservative treatment options are very restricted and reach their limits quickly. Extracorporeal membrane oxygenation (ECMO) is a wellestablished therapy in cardio-thoracic surgery and internal medicine intensive care units. The purpose of this study is to analyse the potential benefit of ECMO therapy in ARDS treatment in polytrauma patients. Retrospective case series. Level 1 trauma centre, Germany, 04/2011-04/2019. Nineteen patients with ARDS treated with a veno-venous ECMO system. This study focused on the time leading to therapy initiation, the severity of thoracic and overall injury. The Sequential Organ Failure Assessment (SOFA) Score, the Murray Score, the Abbreviated Injury Scale (AIS) 2005 level and the Injury Severity Score (ISS) were analysed. The results were analysed regarding survival and death. The survival rate was 53%. The ISS was the same for survivors and deceased patients (p = 0.604). Early initiation of ECMO therapy showed a significant trend for survivors (p = 0.071). The SOFA Score level before ECMO therapy was significantly lower in the survivors than in those who died (p = 0.035). The AISThorax level for survivors showed a significantly higher score level than the one for deceased patients (p = 0.05). ECMO therapy in polytrauma patients is a safe and effective option, in particular when used early in ARDS treatment. The overall severity of organ failure determined the likelihood of survival rather than the thoracic trauma itself.

Severe Ischemic Cardiogenic Shock: Biventricular Impella®, VA-ECMO and Extracorporeal LVAD as Bridge to a Permanent LVAD

Background: Cardiogenic shock (CS) is the clinical representation of circulatory failure with a state of critical end-organ hypoperfusion due to primary cardiac dysfunction. A severe cardiogenic shock can present with clinical complications such as arrhythmias, ischemia and organ failure and even today is associated with a high mortality of 40-50%. Extracorporeal life support (ECLS) by veno-arterial extracorporeal membrane oxygenation (VA-ECMO), Impella® and other mechanical circulatory support systems can reduce the acute circulatory failure and therefore constitute an important treatment option in the management of severe CS as a bridge to long-term strategies.

Predictors of mortality following extracorporeal membrane oxygenation support in an unselected, critically ill patient population.

IntroductionMechanical circulatory support (MCS) has been established as a means of augmenting circulation in patients with critically decreased systolic function due to a variety of underlying clinical reasons. Different methods of MCS may be used, with the venous-arterial extracorporeal membrane oxygenation system (VA-ECMO) being one of the most utilized devices in everyday care.AimTo determine independent predictors influencing mortality outcomes following VA-ECMO therapy in a large, unselected, adult, critically ill patient population in cardiogenic shock (CS).Material and methodsData on 235 consecutive, real-world VA-ECMO treatments were assessed. Analysis was conducted for all subjects requiring MCS with the VA-ECMO as the first instalment, regardless of underlying cause or eventual upgrade. All potential clinical factors influencing mortality were examined and evaluated.ResultsOverall mortality was ~66% at median 28 days follow-up and significantly depended upon pH < 7.3 (HR = 3.56; p < 0.001), and age ≥ 65 years (HR = 1.96; p = 0.001). Acute coronary syndrome (ACS) as an indication for VA-ECMO displayed a nearly significant value (HR = 1.44; p = 0.07). Heart transplant (hTX) primary graft failure as an indication for the VA-ECMO displayed a clearly favorable outcome (HR = 0.51, p = 0.025); all data based on multivariate Cox regression analysis.ConclusionsMortality in patients requiring VA-ECMO remains high. We conclude that only decreased pH values and advanced age clearly influence mortality in this MCS scenario. ACS also bodes unfavorably, whereas hTX as an indication clearly shows better survival.

Use of A New Extracorporeal Membran Oxygenator System and First Experiences

Objective: In this study, we aimed to share our first experiences about the extracorporeal membrane oxygenator (ECMO) system that we have just started to use and compare it with the system we used before.&#x0D; Methods: Between January 2019 and December 2019, 27 consecutive patients under the age of 18 who were operated for congenital heart disease and needed ECMO support were retrospectively analyzed. İn this period The Medos Deltastream diagonal pump and Sorin Revolution ECMO systems were used.&#x0D; Results: Successful wean was observed in six (42.9%) patients in Medos ECMO group and two (15.4%) in Sorin ECMO group. Five (35.7%) patients discharged in the Medos ECMO group. In Sorin ECMO group all patients died. The difference between the groups in terms of the number of patients discharged was statistically significant (p = 0.02). Lactate clearance was 14 hours in Medos ECMO and 48 hours in Sorin ECMO (p = 0.02).&#x0D; Conclusion: In this study, in which we shared our first experiences regarding the first use of the Sorin ECMO system in the postcardiac pediatric patient group, we observed slower lactate clearance, lower succesful wean and higher mortaly rates. Therefore, this should be taken into account during the use of this system.

Coagulation complications after conversion from roller to centrifugal pump in neonatal and pediatric extracorporeal membrane oxygenation

Background/purposeCoagulation complications are frequent, unwanted occurrences in extracorporeal membrane oxygenation (ECMO) treatment, possibly influenced by the pump in the ECMO-circuit. We hypothesized that fewer complications would occur with a smaller, heparin-coated ECMO system with a centrifugal pump (CP) than with one with a roller pump (RP) and that after conversion, complication rates would decrease over time. MethodsThis single-center, retrospective chart study included all first neonatal and pediatric ECMO runs between 2009 and 2015. Differences between groups were assessed with Mann–Whitney U tests and Kruskal–Wallis tests. Determinants of complication rates were evaluated through Poisson regression models. The CP group was divided into three consecutive groups to assess whether complication rates decreased over time. ResultsThe RP group comprised 90 ECMO runs and the CP group 82. Hemorrhagic complication rates were significantly higher with the CP than with the RP, without serious therapeutic consequences, while thrombotic complications rates were unaffected. Intracranial hemorrhage rates and coagulation-related mortality rates were similar. Gained experience with the CP did not improve complication rates or survival over time. ConclusionsAlthough the CP seems safe, it does not seem beneficial over the RP. Further research is warranted on how pump type affects coagulation, taking into account the severity and implications of coagulation complications. Level of EvidenceLevel III.

Intravascular Hemolysis and Complications During Extracorporeal Membrane Oxygenation.

Venovenous and venoarterial extracorporeal membrane oxygenation (ECMO) remains a crucial lifesaving therapy for critically ill neonates with severe cardiorespiratory failure. Both the roller pump as well as the centrifugal pump are safe and efficient systems, and some red blood cell breakdown and hemolysis occurs in all ECMO systems. The roller pump functions by gravity whereas the centrifugal pump promotes the flow of blood by a magnetically driven spinning rotor to generate negative pressure. Extracorporeal Life Support Organization data indicate a significant increase in intravascular hemolysis in neonatal and pediatric patients receiving ECMO when the centrifugal pump is used compared with its use in adults. Risk factors for developing hemolysis during ECMO are small cannula size, high negative inlet pressure in the pump head, and thrombosis in the pump head and oxygenator. Excessive red blood cell breakdown and release of plasma free hemoglobin (pfHb) saturate physiologic neutralizing mechanisms such as haptoglobin and hemopexin. The increase in pro-oxidant and proinflammatory pfHb levels causes endothelial dysfunction in a dose-dependent manner. Hemolysis also increases the risk of in-hospital morbidities such as renal injury, direct hyperbilirubinemia, and thrombosis without an increase in mortality in patients receiving ECMO. Hemolysis is an unavoidable side effect of current ECMO technology and there are no approved treatments or treatment guidelines for the neonatal population. Therefore, increased vigilance, recognition of the severity of the hemolytic process, and prompt management are essential to prevent severe endothelial injury leading to proinflammatory and prothrombotic events.

Continuous amplitude-integrated electroencephalography for prognostication of cardiac arrest patients undergoing extracorporeal cardiopulmonary resuscitation with targeted temperature management

BackgroundExtracorporeal cardiopulmonary resuscitation (ECPR) has been increasingly used for adult cardiac arrest (CA) patients refractory to conventional CPR. However, data on early prognosticators of neurological outcome are lacking. MethodsCA patients undergoing ECPR were prospectively monitored via amplitude-integrated EEG (aEEG). Targeted temperature management (TTM) was induced using an extracorporeal membrane oxygenation system. aEEG background patterns were classified into continuous normal voltage (CNV), discontinuous normal voltage (DNV), low voltage (LV), flat trace (FT), burst suppression (BS), and status epilepticus (SE). The Cerebral Performance Category (CPC) scale scores at hospital discharge and at 6 months after discharge were assessed, as was wakefulness after TTM. Good neurological outcome was defined as a CPC score of 1 or 2. ResultsTwenty-two patients were studied. Six patients who showed CNV within 24 hours after arrival, including one with initial FT and two with initial LV, regained consciousness and had good neurological outcome except for one who died of haemorrhagic complication. Patients with persistent FT or BS at any time did not regain consciousness. Regarding 19 patients in whom aEEG data were obtained within 24 hours, CNV background predicted good outcome at 6 months with 100% sensitivity, 93% specificity, 83% positive predictive values, and 100% negative predictive values. All these indices were 100% concerning wakefulness after TTM. ConclusionaEEG monitoring was feasible and practical in adult CA patients undergoing ECPR and TTM. Evolution of aEEG background within 24 hours provides early accurate information for neurological prognostication.

Neonatal extra corporeal membrane oxygenation.

Extracorporeal life support (ECLS) has been proven to be very useful in the neonatal period. For reversible respiratory and cardiac disorders, when maximal conventional measures have failed to provide life support, extracorporeal membrane oxygenation (ECMO) becomes the treatment of choice. The indications, contra-indications for ECMO, optimization of the care prior to embracing ECMO, cannulation techniques, daily management of ECMO from the practical standpoint, weaning and decannulation, complications, and special circumstances in neonatal period have been described. The follow-up of neonatal ECMO and various system manifestations necessitating careful review will be highlighted.

ECMO-Challenges, strategies, and preparation from Spain.

Providing complex therapies such as extracorporeal membrane oxygenation (ECMO) during outbreaks of infectious diseases has singular challenges. The impact of the SARS‐CoV‐2 pandemic has implied a mentality change by force of circumstances, and cardiac surgery has not been stranger to this trend. The need to treat critically ill patients with an unknown evolution has compelled cardiovascular surgeons to decide whether or not to implant an ECMO system, despite the limited scientific evidence available in the context of COVID‐19. To add some confusion, doubts were raised about its potential deleterious outcome in COVID‐19 patients, due to its effect on lymphocyte counts and interleukin‐6 concentrations. The care of the critically ill patient in a moment of national emergency in Spain took precedence over those possible formal doubts. The Spanish perspective on ventricular assist devices during and after the COVID‐19 pandemic, focused on ECMO as a particular case of mechanical circulatory support, is presented. We address both the challenges posed by the pandemic and the organizational model established in Spain; changes in ECMO therapy and some lessons learned for the next outbreaks are also described. It is not about reinventing the wheel in each country; it is enough to learn from experience and take advantage of the knowledge generated by those who have already gone through similar situations in our environment.

Lean Ad hoc Extracorporeal Membrane Oxygenation Systems for COVID-19.

Coronavirus disease (COVID-19) is overwhelming hospitals with patients requiring respiratory support, including ventilators and Extracorporeal Membrane Oxygenation (ECMO). Bottlenecks in device availability may contribute to mortality, and limited device availability even in ECMO centers has led to rationing recommendations. Therefore, we explored options for ad hoc construction of venovenous ECMO using readily available components, essentially, large cannulas, membrane oxygenators, and blood pumps. As thousands of certified cardiac Impella pumps are distributed worldwide, we assembled lean ECMO by embedding Impella pumps coaxially in tubes, combined with standard gas exchangers. Ad hoc integration of Impella blood pumps with gas exchange modules, large-bore venous cannulas, regular ECMO tubing, Y-pieces, and connectors led to lean ECMO systems with stable performance over several days. Oxygenation of 2.5-5 L of blood per minute is realistic. Benefit/risk analysis appears favorable if a patient needs respiratory support but required support systems in a center are exhausted. Ad hoc assembly of venovenous ECMO is feasible using Impella blood pumps, results in stable blood flow across gas exchange modules, and thus may offer another opportunity to oxygenate, "recover the lungs" and hopefully save lives in selected patients with severe COVID-19 disease even when conventional life support equipment is exhausted. The lean design also yields inspirations for future ECMO systems.

Chlorine inhalation injury with acute respiratory distress syndrome treated by extra-corporeal membrane oxygenation system

Chlorine inhalation related Acute Respiratory Distress Syndrome (ARDS) is rare in clinical practice. Although full recovery from chlorine inhalation injuries remains the most likely outcome, it is true that permanent disability of lung function or even a fatal outcome are possible in severe cases. Reviewing the literature, there are some reports wherein severely injured cases have a mortal outcome. We report a case of high-dose chlorine inhalation injury which induced ARDS and severe acidosis with refractory shock status 4 hours after the initial insult. A vein to artery Extra-Corporeal Membrane Oxygenation (ECMO) system was applied for the ARDS and systemic steroid therapy was also administered. The patient had a good recovery of the pulmonary oxygenation after 70 hours of ECMO support and intubation and ventilation support for five days. He was then transferred to the ward after a one-week stay in the intensive care unit. Oral steroids were gradually tapered over 4 weeks. The follow-up pulmonary function test, performed 6 weeks after the injury, revealed fair recovery without remarkable sequelae while the high resolution pulmonary computed tomography showed bilateral pulmonary fibrosis. To the best of our knowledge, this is the first case report wherein an ECMO system has succeeded in salvaging a patient who suffered from chlorine inhalation injury complicated with ARDS and refractory shock. It is noteworthy that the ECMO system may be deemed beneficial for this group of patients so long as there is no clinical contraindication for the use of such a therapeutic strategy.

Influence of Extracorporeal Membrane Oxygenation Circuit on Nutritional Supplements

Background The main function of extracorporeal membrane oxygenation (ECMO) is to provide systemic perfusion and gas exchange for patients with severe, acute respiratory or cardiac illness. The ECMO system consists of blood pump and a membrane oxygenator. ECMO oxygenator fibers, blood pump and tubing may bind circulating compounds such as drugs and nutritional components during ECMO support. Any loss of vital nutrients due to adsorption to the ECMO circuits may lead to further nutritional debilitation in critical ill patients. Objective The purpose of study is to analyze the amount of nutritional supplements adsorbed to the ECMO circuit under controlled ex vivo conditions Methods Six identical ECMO circuits were primed with fresh human whole blood and maintained under physiological conditions at 36°C for 24 hours. A dose of nutritional supplement calculated for a 70 kg patient was added. 150 mL volume was drawn from priming bag for control samples and kept under similar conditions. Blood samples were obtained at predetermined time points and analyzed for concentrations of vitamins, minerals, lipids, and proteins. Statistical analyses were performed using mixed models with robust standard errors, which allows for repeated samples within each setup and incomplete data. Results No significant differences were found between the ECMO circuits and controls for any of the measured variables: cobalamin, folate, vitamin A, glucose, concentration of minerals, HDL cholesterol, LDL cholesterol, total cholesterol, triglycerides, and total proteins. There was an initial decrease and then and increase in the concentration of cobalamin and folate. Vitamin A concentrations decreased in both groups over time. There was a decrease in concentration of glucose and an increased concentration of lactate dehydrogenase over time in both groups. Conclusion There were no changes in the concentrations of nutritional supplements in an ex vivo ECMO circuit compared to control samples, indicating that parenteral nutrition can be given during ECMO support. However, the time span of this study was limited, and the design made it impossible to investigate any functional and structural changes over time in nutritional supplements which lead to diminished effects through the ECMO circuit.

Extracorporeal membrane oxygenation without therapeutic anticoagulation in adults: A systematic review of the current literature

Extracorporeal membrane oxygenation is essential for the treatment of refractory cardiopulmonary failure. Its use may be complicated by worse haemorrhagic complications exacerbated by extracorporeal membrane oxygenation-related therapeutic anticoagulation. Progressive technological advancements have made extracorporeal membrane oxygenation components less thrombogenic, potentially allowing its application with temporary avoidance of systemic anticoagulants. A systematic review of all the available experiences, reporting the use of extracorporeal membrane oxygenation without systemic anticoagulation in the published literature was performed. Only patient series were included, irrespective of the clinical indication. The survival, extracorporeal membrane oxygenation system-related dysfunction and complications rates, as well as in-hospital outcome, were analysed. Six studies were selected for the analysis. Veno-arterial extracorporeal membrane oxygenation was used in 84% of patients, while veno-venous extracorporeal membrane oxygenation was applied in the remaining cases. Anticoagulation was avoided because of the high risk of bleeding after cardiac surgery (64%), active major bleeding (23%) or presence of severe traumatic injury (9%). Duration of support ranged from 0.3 to 1128 h. Heparin was antagonized by protamine in all the post-cardiotomy cases. Successfully extracorporeal membrane oxygenation weaning was achieved in 74% of the treated cases, with a hospital discharge of 58% of patients. Rates of extracorporeal membrane oxygenation malfunctioning due to clot formation and blood transfusion requirement varied remarkably in the published series. Extracorporeal membrane oxygenation without systemic anticoagulation appears feasible in selected circumstances. Further investigations are warranted to elucidate actual aspects regarding extracorporeal membrane oxygenation system performance, related adverse events and benefits associated with this management.

Addition of a bilateral access form of peripheral extracorporeal membrane oxygenation rescued a patient with idiopathic pulmonary arterial hypertension who developed circulatory collapse immediately after childbirth

Pregnancy is not advised for patients with Pulmonary hypertension (PH) because of high risk of PH crisis. However, some patients have undiagnosed idiopathic pulmonary arterial hypertension (IPAH) before pregnancy. Upfront combination therapy has high efficacy for patients with IPAH. However, some patients are unable to stand until upfront combination therapy has worked sufficiently. The extracorporeal membrane oxygenation (ECMO) system has been proposed as a bridging therapy to recovery for patients with IPAH. Here, we report a case where a novel form of peripheral ECMO assist plus upfront combination therapy containing intravenous epoprostenol rescued a female patient diagnosed with IPAH just after childbirth. Following this treatment, the patient could successfully transition from intravenous epoprostenol to oral selexipag.

In vivo perfusion of free skin flaps using extracorporeal membrane oxygenation

BackgroundThe vessel-depleted, irradiated, and frozen neck, as well as severe atherosclerosis of recipient vessels represent challenging problems in free flap transfer. Extracorporeal free flap perfusion theoretically allows free flap reconstructions in the absence of local donor vessels, but is associated with a number of technical issues. In this study, a novel technique is presented using a commercially available system for extracorporeal membrane oxygenation (ECMO), modified for small blood volumes. MethodsAfter preclinical testing, an ECMO system certified for lung support was used to establish blood flow through the flap's artery with oxygenation, decarboxylation and warming of diluted packed blood cells. Venous blood was allowed to flow passively into a separate container. Perfusion was performed for 15 min at intervals of 4 h over 4–6 days. ResultsFive patients with soft tissue defects requiring free flap reconstruction were included. Either primarily thinned anterolateral thigh (ALT) flaps (n = 3) or radial forearm flaps (n = 2) were used. We observed infection of the perfusate, with consequent subtotal flap loss, in one patient, complete epithelial loss in two patients, venous congestion in one case, and almost uneventful healing in the fifth patient. With conservative wound care and a split thickness skin graft in one case, stable wound coverage was achieved in all patients except one, who had secondary healing. None of the patients required a second flap for sufficient coverage. ConclusionsThe technique described is associated with the risks of infection, flap congestion, nutritive hypoperfusion, and consequent tissue loss. Nevertheless, stable defect closure seems to be achievable even in patients with depleted recipient vessels.