Minimal invasive extracorporeal circulation an alternative to ECMO in ventricular tachycardia ablation.

BACKGROUND: The advantages of mechanical assistance during ventricular tachycardia (VT) ablation have not been clinically demonstrated. We propose and discuss a technique, set up by us, that makes use of minimally invasive extra-corporeal circulation (MiECC) type III associated with a venous reservoir system, which allows complete cardiac flow support and blood oxygenation as well as hemodynamic stability during long-lasting procedures. METHODS: We present a retrospective case series of ten patients with valvular heart disease and unresponsive Ventricular Tachycardia (VT) who underwent VT ablation with MiECC support. The mean age of the patients was 72 ± 8 years and the left ventricular ejection fraction was 36 ± 12%. All patients underwent a clinical evaluation to identify the cause of VT unresponsiveness (e.g., ischemic heart disease). RESULTS: A total of 140 min, the following parameters were evaluated and recorded for 140 min. Central venous pressure (CVP) was used to evaluate excess volume. During the first 5 min, the mean was 15 mmHg, with a pump flow of 1.5 L/min and a mean systemic arterial pressure of 100 mmHg while setting up the circulation support. Following drainage in a volumetric bag of 1 L of blood, CVP was reduced to a value of 5 mmHg with a flow rate of 5 L/min and a mean systemic arterial pressure of 65 mmHg. In the case of small and low-weight patients our "1 L protocol" can be modified. CONCLUSIONS: In this preliminary retrospective case series, the MiECC type III system may represent the ideal support system during VT ablation, and further studies are needed to support this preliminary report.

Influence of minimal invasive extracorporeal circuits on dialysis dependent patients undergoing cardiac surgery.

INTRODUCTION: Cardiac surgery in patients on chronic renal dialysis is associated with significant morbidity and mortality. Minimally invasive extracorporeal circuits (MiECC) have shown a positive impact on patient outcome in different high-risk populations. This retrospective study compares the outcome of these high-risk patients undergoing heart surgery either with a MiECC or a conventional extracorporeal circulation (CECC). METHODS: This is a single-center experience including 131 consecutive dialysis dependent patients undergoing cardiac surgery between January 2006 and December 2016. A propensity score matching was employed leaving 30 matched cases in each group. RESULTS: After propensity score matching the 30-day mortality was significantly lower in the MiECC group (n = 3 (10%) vs n = 10 (33%) in the CECC group, p = .028). Further, intraoperative transfused units of packed red blood cells were lower in the MiECC group (1.4 ± 1.8 units vs 2.8 ± 1.7, p < .001). CONCLUSIONS: There are evident advantages to using MiECC in dialysis dependent patients, especially regarding mortality. These findings necessitate additional research in MiECC usage in high-risk populations.

Impact of minimal invasive extracorporeal circulation on perioperative intravenous fluid management in coronary artery bypass surgery.

OBJECTIVE: Compare the use of blood products and intravenous fluid management in patients scheduled for coronary artery bypass surgery and randomized to minimal invasive extracorporeal circulation (MiECC) and conventional extracorporeal circulation (CECC). METHODS: A total of 240 patients who were scheduled for their first on-pump CABG, were randomized to MiECC or CECC groups. The study period was the first 84 hours after surgery. Hemoglobin <80 g/l was used as transfusion trigger. RESULTS: Red blood cell transfusions intraoperatively were given less often in the MiECC group (23.3% vs 9.2%, p = 0.005) and the total intravenous fluid intake was significantly lower in the MiECC group (3300 ml [2950-4000] vs 4800 ml [4000-5500], p < 0.001). Hemoglobin drop also was lower in the MiECC group (35.5 ± 8.9 g/l vs 50.7 ± 9 g/l, p < 0.001) as was hemoglobin drop percent (25.3 ± 6% vs 35.3 ± 5.9%, p < 0.001). Chest tube drainage output was higher in the MiECC group (645 ml [500-917.5] vs 550 ml [412.5-750], p = 0.001). Particularly, chest tube drainage in up to 600 ml category, was in benefit of CECC group (59.1% vs 40.8%, p = 0.003). ROC curve analysis showed that patients with hemoglobin level below 95 g/l upon arrival to intensive care unit was associated with increased risk of developing postoperative atrial fibrillation (POAF) (p = 0.002, auc = 0.61, cutoff <95, sensitivity = 0.47, positive predictive value = 0.64). CONCLUSION: MiECC reduced the intraoperative need for RBC transfusion and intravenous fluids compared to the CECC group, also reducing hemoglobin drop compared to the CECC group in CABG surgery patients. Postoperative hemoglobin drop was a predictor of POAF.

The use of minimal invasive extracorporeal circulation for rewarming after accidental hypothermia and circulatory arrest.

BACKGROUND: Extracorporeal cardiopulmonary resuscitation has become a recommended treatment option for patients with severe hypothermia with cardiac arrest. Minimal invasive extracorporeal circulation (MiECC) may offer advantages over the current standard extracorporeal membrane oxygenation (ECMO). METHODS: Retrospective cohort analysis of hospital database for patients with accidental hypothermia and extracorporeal rewarming with MiECC admitted between 2010 and 2019. RESULTS: Overall, six of 17 patients survived to hospital discharge. Eleven patients suffered accidental hypothermia in an alpine and six in an urban setting. Sixteen patients arrived at the hospital under ongoing cardiopulmonary resuscitation (CPR). CPR time was 90 minutes (0-150). Four patients survived from an alpine setting and two from an urban setting with CPR duration of 90 minutes (0-150) and 85 minutes (25-100), respectively. Asphyctic patients tended to have lower survival (one of seven patients). Two patients of six with major trauma survived. CONCLUSION: MiECC for extracorporeal rewarming from severe accidental hypothermia is a feasible alternative to ECMO, with comparable survival rates.

Hematic Antegrade Repriming: A Reproducible Method to Decrease the Cardiopulmonary Bypass Insult.

The current practice of cardiopulmonary bypass (CPB) requires a preoperative priming of the circuit that is frequently performed with crystalloid solutions. Crystalloid priming avoids massive embolism but is unable to eliminate all microbubbles contained in the circuit. In addition, it causes a sudden hemodilution which is correlated with transfusion requirements and an increased risk of cognitive impairment. Several repriming techniques using autologous blood, collectively termed retrograde autologous priming (RAP), have been demonstrated to reduce the hemodilutional impact of CPB. However, the current heterogeneity in the practice of RAP limits its evidence and benefits. Here, we describe hematic antegrade repriming as an easy and reliable method that could be applied with any circuit in the market to decrease transfusion requirements, emboli, and inflammatory responses, reducing costs and the impact of CPB on postoperative recovery.

Minimally invasive aortic valve replacement: extracorporeal circulation optimization and minimally invasive extracorporeal circulation system evolution.

Treatment of aortic valve disease has become less and less invasive during the last years, thanks to progress in anesthesiology, surgical techniques, and perfusion management. In fact, it has been demonstrated that shorter skin incision, combined with ultra-fast-track anesthesia and minimized extracorporeal circuit could improve clinical outcomes. Current evidence shows that minimally invasive extracorporeal circulation system is associated with reduced red blood cells' transfusion rate, improved end-organ perfusion, decreased incidence of postoperative atrial fibrillation, air embolism leakage, and so less cerebral accidents with better neurological outcomes. Moreover, the use of a closed circuit seems to be more physiologic for the patients, reducing systemic inflammatory response due to less air-blood contact and the use of biocompatible surfaces. In the literature, the benefits of minimally invasive extracorporeal circulation are described mostly for coronary surgery but few data are nowadays available for minimally invasive extracorporeal circulation during aortic valve replacement. In this article, we describe our perfusion protocol in minimally invasive aortic valve replacement.

Hemodynamic energy during pulsatile extracorporeal circulation using flexible and rigid arterial tubing: a reassessment.

INTRODUCTION: Pulsatile extracorporeal circulation may improve organ perfusion during cardiac surgery. Some minimally invasive extracorporeal circulation (MiECC) systems allow pulsatile perfusion. The present study investigated the influence of arterial tubing compliance on hemodynamic energy transfer into the patient. METHODS: Aortic models with adult human geometry were perfused in a mock circulation. A MiECC system was connected using either high-compliance silicone tubing or standard kit tubing. Energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE) were computed from flow and pressure data. Aortic models with physiological and sub-physiological compliance were tested to assess the influence of the pseudo-patient. RESULTS: Non-pulsatile flow did not generate SHE. SHE during pulsatile flow in the compliant aortic model was significantly higher with kit tubing compared to silicone tubing. Maximum SHE was achieved at 1.6 L/min with kit tubing (7.7% of mean arterial pressure) and with silicone tubing (4.9%). Using the low-compliance aortic model, SHE with kit tubing reached a higher maximum of 14.2% at 1.8 L/min compared to silicone tubing (11.8% at 1.5 L/min). CONCLUSIONS: Flexible arterial tubing did not preserve more hemodynamic energy from a pulsatile pump compared to standard kit tubing in a model of adult extracorporeal circulation. The pseudo-patient's compliance significantly affected the properties of the mock circulation.

Shed-blood-separation and cell-saver: an integral Part of MiECC? Shed-blood-separation and its influence on the perioperative inflammatory response during coronary revascularization with minimal invasive extracorporeal circulation systems - a randomized controlled trial.

OBJECTIVE: The postoperative systemic inflammatory response after cardiopulmonary bypass (CPB) is still an undesirable side-effect after cardiac surgery. It is most likely caused by blood contact with foreign surfaces and by the surgical trauma itself. However, the recirculation of activated shed mediastinal blood is another main cause of blood cell activation and cytokine release. Minimal invasive extracorporeal circulation (MiECC) comprises a completely closed circuit, coated surfaces and the separation of suction blood. We hypothesized that MiECC, with separated cell saved blood, would induce less of a systemic inflammatory response than MiECC with no cell-saver. The aim of this study was, therefore, to investigate the impact of cell washing shed blood from the operating field versus direct return to the ECC on the biomarkers for systemic inflammation. MATERIAL AND METHODS: In the study, patients with MiECC and cell-saver were compared with the control group, patients with MiECC and direct re-transfusion of the drawn blood shed from the surgical field. RESULTS: High amounts of TNF-α (+ 120% compared to serum blood) were found in the shed blood itself, but a significant reduction was demonstrated with the use of a cell-saver (TNF-α ng/l post-ECC 10 min: 9.5±3.5 vs. 19.7±14.5, p<0.0001). The values for procalcitonin were not significantly increased in the control group (6h: 1.07±3.4 vs. 2.15±9.55, p=0.19) and lower for C-reactive protein (CRP) (24h: 147.1±64.0 vs.134.4±52.4 p=0.28). CONCLUSION: The use of a cell-saver and the processing of shed blood as an integral part of MiECC significantly reduces the systemic cytokine load. We, therefore, recommend the integration of cell-saving devices in MiECC to reduce the perioperative inflammatory response.

A comparison between minimized extracorporeal circuits and conventional extracorporeal circuits in patients undergoing aortic valve surgery: is 'minimally invasive extracorporeal circulation' just low prime or closed loop perfusion ?

INTRODUCTION: Even though results have been encouraging, an unequivocal conclusion on the beneficial effect of minimally invasive extracorporeal circulation (MiECC) in patients undergoing aortic valve surgery cannot be derived from previous publications. Long-term outcomes are rarely reported and a significant decrease in operative mortality has not been shown. Most studies have a limited number of patients and are underpowered. They merely report on short-term results of a heterogeneous intraoperative group using different types of ECC system in aortic valve surgery. The aim of the present study was to determine whether MiECC systems are more beneficial than conventional extracorporeal systems (CECC) with regard to mortality, hospital stay and inflammation and with only haemodilution and blood-air interface as differences. METHODS: We retrospectively analysed data regarding mortality, hospital stay and inflammation in patients undergoing isolated aortic valve surgery. Forty patients were divided into two groups based on the type of extracorporeal system used; conventional (n=20) or MiECC (n=20). RESULTS: Perioperative blood product requirements were significantly lower in the MiECC group (MiECC: 0.2±0.5 units vs CECC: 0.9±1.2 units, p=0.004). No differences were seen postoperatively regarding mortality (5% vs 5%, p=0.99), total length of hospital stay (10.6±7.2 days (MiECC) vs 12.1±5.9 days (CECC), p=0.39) or inflammation markers (CRP: MiECC: 7.09±13.62 mg/L vs CECC: 3.4±3.2 mg/L, p=0.89). CONCLUSION: MiECC provides circulatory support that is equally safe and feasible as conventional extracorporeal circuits. No differences in mortality, hospital stay or inflammation markers were observed.

Minimally invasive extracorporeal circulation in end-stage coronary artery disease patients undergoing myocardial revascularization.

BACKGROUND: Patients with coronary artery disease and concomitant heart failure (left ventricular ejection fraction < 35%) requiring myocardial revascularization are at risk of poor long-term prognosis and higher mortality. The benefits of minimally invasive extracorporeal circulation (MiECC), particularly in end-stage coronary artery disease patients undergoing myocardial revascularization, have not been completely described. MATERIALS AND METHODS: In this single-centre control study, 60 end-stage coronary artery disease patients undergoing isolated coronary artery bypass grafting (CABG) were included. Patients were divided into two groups of 30 patients each undergoing CABG using MiECC or conventional extracorporeal circulation (cECC). RESULTS: In the MiECC group, oxygen delivery index (DO2i) was 305 mL/min/m2 in relation to indexed oxygen extraction ratio (O2ERi) 21.5%, whereas in the cECC group DO2i was 288 mL/min/m2 in relation to O2ERi 25.6% (p = 0.037). Lactate levels > 3 mmol/L were reported in 7 MiECC patients vs 20 cECC patients (p = 0.038), with blood glucose peak. Mean nadir hemoglobin values during cardiopulmonary bypass (CPB) were 9.7 g/dL in the MiECC group vs 7.8 g/dL in the cECC group (p = 0.044). Cardiac index during CPB was 2.4 L/min/m2 in both groups. Red blood cell units administered were 8 vs 21 units in the MiECC vs cECC group (p = 0.022). A glycemic peak was recorded in 7 patients of the MiECC group and in 20 patients of the cECC group (p = 0.037). CONCLUSION: In end-stage coronary artery disease, the MiECC technique was associated with a higher DO2i compared to cECC. MiECC patients showed a significant reduction in red blood cell unit administration and peak intraoperative lactate levels, which correlated with better postoperative outcome.

From less invasive to minimal invasive extracorporeal circulation.

Development of minimally invasive cardiac surgery (MICS) served the purpose of performing surgery while avoiding the surgical stress triggered by a full median sternotomy. Minimizing surgical trauma is associated with improved cosmesis and enhanced recovery leading to reduced morbidity. However, it has to be primarily appreciated that the extracorporeal circulation (ECC) stands for the basis of nearly all MICS procedures. With some fundamental modification and advancement in perfusion techniques, the use of ECC has become the enabling technology for the development of MICS. Less invasive cardiopulmonary bypass (CPB) techniques are based on remote cannulation and optimization of perfusion techniques with assisted venous drainage and use of centrifugal pump, so as to facilitate the demanding surgical maneuvers, rather than minimizing the invasiveness of the CPB. This is reflected in the increased duration of CPB required for MICS procedures. Minimal invasive Extracorporeal Circulation (MiECC) represents a major breakthrough in perfusion. It integrates all contemporary technological advancements that facilitate best applying cardiovascular physiology to intraoperative perfusion. Consequently, MiECC use translates to improved end-organ protection and clinical outcome, as evidenced in multiple clinical trials and meta-analyses. MICS performed with MiECC provides the basis for developing a multidisciplinary intraoperative strategy towards a "more physiologic" cardiac surgery by combining small surgical trauma with minimum body's physiology derangement. Integration of MiECC can advance MICS from non-full sternotomy for selected patients to a "more physiologic" surgery, which represents the real face of modern cardiac surgery in the transcatheter era.

Initial experiences with a centrifugal-pump based minimal invasive extracorporeal circulation system in pediatric congenital cardiac surgery.

BACKGROUND: Minimal invasive extracorporeal circulation (MiECC) circuits are an established alternative to conventional extracorporeal circulation (CECC). Based on the positive effects and improved perioperative outcomes of MiECC in adult cardiac surgery, this perfusion concept appears particularly attractive to pediatric cardiac surgery. So far, there are no reports on the clinical application of a MiECC system for corrective surgery in neonates and children. We report our initial experiences by using a MiECC system in pediatric cardiac surgery. METHODS: A total of 38 pediatric patients underwent surgical interventions for a variety of congenital heart disease from March 2017 until August 2018 with a MiECC. Following the classification of MiECC circuits by the Minimal invasive Extra-Corporeal Technologies International Society (MiECTIS), type I and type III perfusion circuits were assembled depending on the planned intervention: type I for closed heart interventions and type III for open heart procedures. Primary outcome was conversion to CECC, secondary endpoints included major adverse cardiac or cerebrovascular events (MACCE). RESULTS: MiECC perfusion was successfully performed in all patients (100%). Median patient age was 9.5 months (range, 0.2-176 months) with a median weight of 8.1 kg (range, 2.3-49 kg). For both MiECC types no system related technical complications were encountered. Beating heart procedures were performed in 23 cases (60%) at normothermia, while in 15 (40%) interventions cardioplegic cardiac arrest was induced at mild hypothermia. All patients had an uneventful perioperative course with no in-hospital mortality. MACCE did not occur during the hospitalization period. CONCLUSIONS: MiECC can be performed by using standard techniques for closed and open cardiac procedures for the correction of a variety of malformations in neonates and children with good results and uneventful postoperative course.

Inflammation and coagulation following minimally invasive extracorporeal circulation technologies.

Minimally invasive extracorporeal perfusion technologies are based on the use of a minimally invasive extracorporeal circulation (MiECC) system. This includes a closed CPB circuit; biologically inert blood contact surfaces; reduced priming volume; a centrifugal pump; a membrane oxygenator; a heat exchanger; a cardioplegia system; a venous bubble trap/venous air removing device; and a shed blood management system. Some of these items, alone or in combination, are able to modify the blood activation usually elicited by cardiopulmonary bypass (CPB). The hemostatic system activation is less activated and lower degrees of thrombin generation and platelet activation have been found in numerous studies. Additionally, the reduced level of hemodilution plays an important role in preserving clot firmness after CPB with MiECC. These biochemical changes are reflected by a blood loss containment, a reduced need for allogeneic blood transfusions, and, in some studies, by a lower thromboembolic complications rate. The activation of the inflammatory cascade is in turn limited by MiECC, both directly (through a blunting of the contact-phase activation) and indirectly (through a limited thrombin generation, platelet activation, and consequent lower release of pro-inflammatory cytokines). The clinical consequences of this are mainly demonstrated by a lower rate of postoperative atrial fibrillation; other inflammation-derived outcomes appear favorably affected by MiECC (lung function, acute kidney injury) but the multi-factorial nature of these complications makes difficult to clearly attribute this pattern to a lower degree of inflammation. Overall, the existing body of evidence is in favor of MiECC with respect to standard CPB.

Monitoring and optimization of the microcirculation during CPB.

In this review the impact of cardiopulmonary bypass (CPB) on the microcirculation is discussed. The impact of conventional non-pulsatile perfusion is contrasted with the microcirculatory impact of pulsatile CPB which is associated with better preservation of microcirculatory function. Evidence that alterations in microcirculatory function that persist following cardiac surgery are associated with adverse clinical outcomes is reviewed. Recent studies using novel techniques employing near infrared reflectance spectroscopy (NIRS) and sublingual microscopy to explore alterations in microcirculatory function during CPB are reviewed and the implications of these observations for studies investigating minimally invasive extracorporeal circulation (MiECC) are discussed.

Ultra fast track surgery: a rapid deployment aortic valve replacement through a J-ministernotomy.

Aortic valve surgery has been undergone continuous development over the last years, involving less invasive techniques and the use of new technologies to reduce the traumatic impact of the intervention and extend the operability toward increasingly high-risk patients. Minimally invasive aortic valve replacement (AVR) has gradually been recognized as a less traumatic technique compared to median sternotomy, becoming first choice approach in numerous experienced centers. Herein we present our multidisciplinary minimally invasive approach for AVR, involving: (I) reduced chest incision; (II) rapid deployment AVR; (III) minimally invasive extracorporeal circulation system; and (IV) ultra fast track (UFT) anaesthetic management.