Veno-venous extracorporeal membrane oxygenation using an innovative dual-lumen cannula following implantation of a total artificial heart.

We report our first clinical use of the new Protek DuoTM cannula for peripheral veno-venous extra-corporeal life support (ECLS). A 53-year-old male patient underwent implantation of a total artificial heart (TAH) for biventricular failure. However, due to the development of post-operative respiratory dysfunction, the patient required ECLS for six days.

Hybrid ECMO for a patient in respiratory failure developing cardiac insufficiency.

A 45-year-old patient in lung failure treated with veno-venous extracorporeal membrane oxygenation (VV ECMO) developed subsequent right heart failure and required cardiac support.We present a method of upgrading a VV ECMO to a hybrid system for simultaneous support for respiratory and cardiac failure.

Pearls and pitfalls in short-term mechanical circulatory assist: how to avoid and manage complications.

In today's era, given the worsening risk profiles of patients undergoing cardiac surgery, the increasing number of complex cardiac surgeries, and the increasing number of patients undergoing thoracic organ transplantation, short-term mechanical circulatory assist (MCA) devices are indispensable. MCA devices are capable of supporting heart and lung function and have emerged as potentially lifesaving instruments, but may prove to be as hazardous as helpful due to their inherent tendency toward hemolysis, thromboembolism, and hemorrhage. Although MCA devices are being used regularly at some specialized centers, surgeries involving MCA are not as common as other routine cardiac surgeries, and even though professionals implanting and maintaining short-term MCAs are well acquainted with operating such devices, it is not uncommon to come across complications as a result of minor mistakes committed while dealing with them. Avoiding simple mistakes and taking proper precautions while implanting and maintaining these devices can prevent major catastrophes. We discuss commonly encountered problems and complications during the implantation and maintenance of short-term MCAs and offer reasonable and practical solutions. In addition, crucial issues such as anticoagulation, replacement of the device circuit, and management of the distal perfusion cannula are discussed. Continuous and efficient monitoring of the MCA device and the patient supported on MCA, together with anticipation and avoidance of complications, is key for successful short-term MCA support.

Distal limb perfusion: Achilles' heel in peripheral venoarterial extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) is a temporary mechanical circulatory assist method that offers circulatory as well as respiratory support efficiently via peripheral access; however, it is liable to complications. Limb ischemia is one of the notorious complications of ECMO but can be avoided utilizing a proper distal limb perfusion method. A retrospective study of patients undergoing peripheral venoarterial (VA) ECMO for various reasons between June 2010 and December 2012 was performed. All patients were evaluated by our multidisciplinary team for suitability as candidates for ECMO. A peripheral VA-ECMO circuit was implanted via groin: inflow cannula in the femoral vein, an outflow cannula and distal-perfusion cannula, or an introducer sheath in the femoral artery. During the study period, 83 patients underwent various types of ECMO; 45 received peripheral VA-ECMO. Distal limb perfusion was achieved with an introducer sheath (6-8 Fr) in 13 cases and with a distal-perfusion cannula (10-12 Fr) in 32 cases. Nine (20%) patients developed signs of ischemia; five (11.2%) were treated conservatively, while four (8.8%) required surgical intervention. One patient required a below-knee amputation. The incidences of limb ischemia and limb ischemia requiring surgical intervention were significantly higher for the introducer sheath compared with the cannula (30.6 vs. 15.6% and 15.4 vs. 6.25%, respectively). Moreover, the patients supported on ECMO with a distal-perfusion cannula spent a significantly longer time on ECMO compared with the ones in whom an introducer sheath was used (11.9 ± 9.1 vs. 7.7 ± 4.3 days). The mean cannula size was significantly greater than the mean introducer sheath size (11.1 ± 1.3 vs. 7.0 ± 1.1 Fr). Use of a distal-perfusion cannula is a most reliable method of limb perfusion in peripheral VA-ECMO. The cannula can ensure adequate and smooth perfusion of the limb owing to its large caliber, its less turbulent flow, the ability it provides to monitor the flow, and the option to attach a side port.

Variable Sequestration of Antifungals in an Extracorporeal Membrane Oxygenation Circuit.

Fungal infections are common and frequently associated with clinical failure in patients receiving extracorporeal membrane oxygenation (ECMO). Antifungal drugs have physicochemical characteristics associated with a higher likelihood of sequestration onto ECMO circuitry potentially leading to a subtherapeutic drug concentration. The percentage of sequestration of the antifungal drugs-caspofungin, posaconazole, and voriconazole-was determined using an ex vivo ECMO model. The circuits were primed with whole human blood, sodium chloride 0.9%, and human albumin solution. Serial 2 ml samples were taken at baseline, 0.5, 1, 2, 6, 12, and 24 hours after drug addition, paired with non-ECMO controls stored in a water bath at 37°C. Mean loss from the blood-primed ECMO circuits and controls at 24 hours relative to baseline were 80% and 61% for caspofungin ( p = ns), 64% and 11% for posaconazole ( p < 0.005), and 27% and 19% for voriconazole ( p < 0.05). Calculated AUC 0-24 showed a 44% for caspofungin ( p = ns), 30.6% posaconazole ( p < 0.005), and 9% loss for voriconazole ( p = 0.003) compared with the controls, suggesting therapeutic concentrations of these antifungal agents cannot be guaranteed with standard dosing in patients on ECMO. Posaconazole exhibited the greatest loss to the ECMO circuit correlating with both high lipophilicity and protein binding of the drug.

Utilization of Paragonix SherpaPak for human donor heart preservation.

A heart transplant is the gold standard treatment for end stage heart failure. Preservation of the donor heart during its transfer from the hospital of the donor to that of the recipient has a significant impact on the outcome of the transplant procedure. Icebox storage is a conventional method utilized for this purpose that may not provide uniform cooling of the donor heart and does not allow monitoring of the temperature of the donor heart during preservation. The Paragonix SherpaPak Cardiac Transport System offers uniform cooling by suspending the donor heart in a preservation solution and provides continuous temperature monitoring.

Ex vivo lung perfusion made easy.

Ex vivo lung perfusion is an indispensable tool in the armamentarium of any lung transplant center. It helps to increase an already shrinking donor pool by offering a chance to assess suboptimal donor lungs in a systematic manner and improve them by treating them with low-molecular-weight perfusate. We offer a stepwise guide to carry out ex vivo lung perfusion on the donor lungs and criteria to accept them for transplants.

Direct Heart Procurement After Donation After Circulatory Death With Ex Situ Reperfusion.

The most extended technique of heart procurement from donors after circulatory death involves direct procurement and reperfusion in an ex situ normothermic platform using the Organ Care System (TransMedics, Inc, Andover, MA). This report describes a modified technique (at the Harefield Hospital, London, United Kingdom) with rapid donor blood drainage using a cell-saving device and synchronized perfusion on the Organ Care System.

Comparison of temporary ventricular assist devices and extracorporeal life support in post-cardiotomy cardiogenic shock.

OBJECTIVES: Post-cardiotomy cardiogenic shock (PCCS) results in substantial morbidity and mortality, whereas refractory cases require mechanical circulatory support (MCS). The aim of the study was to compare extracorporeal membrane oxygenation (ECMO) and ventricular assist devices (VADs) utilized in the management of PCCS. METHODS: In total, 56 consecutive patients who developed PCCS from 2005 to 2014 required MCS as a bridge to decision-24 were supported with a VAD and 32 with an ECMO. Groups were compared with respect to pre- and intraoperative characteristics and early and long-term outcomes to evaluate the impact of the type of MCS on complications and survival. Data are mean ± standard deviation and median with quartiles. RESULTS: EuroSCORE II was significantly higher in the VAD group than in the ECMO group (28 ± 20 vs 13 ± 16, P = 0.020) corresponding to significantly higher New York Heart Association (P = 0.031) class and Canadian Cardiovascular Society class (P = 0.040) in the cohort. The median duration of support was 10 (4-23) and 7 (4-10) days in the VAD and ECMO groups, respectively. There were no significant differences in ITU (P = 0.262), hospital stay (P = 0.193) and incidences of most postoperative complications. A significantly higher proportion of patients was successfully weaned/upgraded in the VAD group [13 (54%) vs 4 (13%), P = 0.048] with a trend towards higher discharge rate [9 (38%) vs 5 (16%), P = 0.061]. Overall cumulative survival in early follow-up [Breslow (Generalized Wilcoxon) P = 0.017] and long-term follow-up [Log-rank (Mantel-Cox) p = 0.015] was significantly better in the VAD group. CONCLUSIONS: VAD and ECMO represent essential tools to support patients with PCCS. Our preliminary results might indicate some benefits of using VAD in this group of patients; however, this evidence should be further assessed in larger multicentre trials.

Extracorporeal life support in patients with refractory cardiogenic shock: keep them awake.

OBJECTIVES: Traditionally, patients on extracorporeal life support (ECLS) are sedated and mechanically ventilated and therefore prone to complications related to immobility and ventilation. We adopted this 'Awake ECLS' strategy for the patients with refractory cardiogenic shock (RCS) as a bridge to decision. METHODS: Sixty-eight patients with RCS were supported by ECLS (All veno-arterial) in years 2010-2014. Patients that could not survive 24 h after ECLS implantation (9 patients) were excluded from the study. Study population constituted 59 patients-'Awake' group (n = 18; maintained awake without intubation) and 'Control' group (n = 41; intubated and required mechanical ventilation). RESULTS: Nine (50%) patients were awake at implantation, with 5 of them remaining free of sedation and ventilator support through to explantation. Nine patients were ventilated at the time of implantation but subsequently extubated and remained non-intubated and ventilator free. Post-ECLS survival at 1 month was 78 and 42% while the survival to discharge was 78 and 37% in awake and control group, respectively. CONCLUSIONS: ECLS as a bridge to decision in RCS is effective in restoring adequate systemic perfusion and recovering end-organ function. ECLS can be initiated in awake patients with RCS and patients can be awakened on ECLS. The 'awake ECLS' strategy may avoid complications related to mechanical ventilation, sedation and immobilization. RCS patients supported on ECLS without severe metabolic acidosis, multiorgan failure, intra-aortic balloon pump or uncertain neurological status are more likely to be weaned from the ventilator. Patients that are awake at the time of ECLS implantation are more likely to remain awake during ECLS.

Evaluation of the organ care system in heart transplantation with an adverse donor/recipient profile.

BACKGROUND: A severe shortage of available donor organs has created an impetus to use extended criteria organs for heart transplantation. Although such attempts increase donor organ availability, they may result in an adverse donor-recipient risk profile. The TransMedics Organ Care System (OCS) (TransMedics, Inc, Boston) allows preservation of the donor heart by perfusing the organ at 34°C in a beating state, potentially reducing the detrimental effect of cold storage and providing additional assessment options. We describe a single-center experience with the OCS in high-risk heart transplant procedures. METHODS: Thirty hearts were preserved using the OCS between February 2013 and January 2014, 26 of which (86.7%) were transplanted. Procedures were classified as high risk based on (1) donor factors, ie, transport time more than 2.5 hours with estimated ischemic time longer than 4 hours, left ventricular ejection fraction (LVEF) less than 50%, left ventricular hypertrophy (LVH), donor cardiac arrest, alcohol/drug abuse, coronary artery disease or (2) recipient factors, ie, mechanical circulatory support or elevated pulmonary vascular resistance (PVR), or both. RESULTS: Donor and recipient age was 37 ± 12 years and 43 ± 13 years, respectively. Allograft cold ischemia time was 85 ± 17 minutes and OCS perfusion time was 284 ± 90 minutes. The median intensive care unit stay was 6 days. One death (3.8%) was observed over the follow-up: 257 ± 116 (109-445 days). There was preserved allograft function in 92% of patients, with a mean LVEF of 64% ± 5%. CONCLUSIONS: Use of the OCS is associated with markedly improved short-term outcomes and transplant activity by allowing use of organs previously not considered suitable for transplantation or selection of higher risk recipients, or both.

CentriMag short-term ventricular assist as a bridge to solution in patients with advanced heart failure: use beyond 30 days.

OBJECTIVES: Left ventricular assist devices (LVADs) offer very valuable therapeutic options for patients with advanced heart failure. CentriMag (Thoratec, Pleasanton, CA, USA) is an extracorporeal short-term circulatory assist device Conformité Européenne-marked in Europe for use up to 30 days. METHODS: Retrospective analysis of 41 patients with advanced heart failure who, from 2003 to 2011, were supported with CentriMag for >30 days as a bridge to recovery, long-term VAD or transplantation. RESULTS: Forty-one adult patients were supported with 46 CentriMag devices for a total of 2695 days with a mean support time of 59 (range: 31-167) days. Indications were post-cardiotomy cardiogenic shock (PC = 4), primary graft failure (PGF = 7) and refractory heart failure (RHF = 35). Six devices were used to support the left ventricle, 19 to support the right ventricle and 21 to support both the ventricles (biventricular support considered as single device unit). In the PC cohort, 3 (75%) patients were weaned from support, while 4 (57%) were weaned from support in the PGF cohort. In the RHF cohort, 8 patients were bridged to long-term VAD and 5 were bridged to transplantation; heart function recovered and device explanted in 14, while 8 patients died on support. There were no device failures. Overall, 34 (74%) patients were recovered or bridged, with a 1-year survival of 54%. CONCLUSIONS: CentriMag proved to be a versatile, safe and effective short-term circulatory support for patients with advanced heart failure as a bridge to solution. Its use over 30 days is associated with acceptable survival and does not increase device-related complications.

Superior flow for bridge to life with self-expanding venous cannulas.

BACKGROUND: Recently, a compact cardiopulmonary support (CPS) system designed for quick set-up for example, during emergency cannulation, has been introduced. Traditional rectilinear percutaneous cannulas are standard for remote vascular access with the original design. The present study was designed to assess the potential of performance increase by the introduction of next-generation, self-expanding venous cannulas, which can take advantage of the luminal width of the venous vasculature despite a relatively small access orifice. METHODS: Veno-arterial bypass was established in three bovine experiments (69+/-10 kg). The Lifebridge (Lifebridge GmbH, Munich, Germany) system was connected to the right atrium in a trans-jugular fashion with various venous cannulas; and the oxygenated blood was returned through the carotid artery with a 17 F percutaneous cannula. Two different venous cannulas were studied, and the correlation between the centrifugal pump speed (1500-3900 RPM), flow and the required negative pressure on the venous side was established: (A) Biomedicus 19 F (Medtronic, Tolochenaz, Switzerland); (B) Smart canula 18 F/36 F (Smartcanula LLC, Lausanne, Switzerland). RESULTS: At 1500 RPM, the blood flow was 0.44+/-0.26 l min(-1) for the 19 F rectilinear cannula versus 0.73+/-0.34 l min(-1) for the 18/36 F self-expanding cannula. At 2500 RPM the blood flow was 1.63+/-0.62 l min(-1) for the 19F rectilinear cannula versus 2.13+/-0.34 l min(-1) for the 18/36 F self-expanding cannula. At 3500 RPM, the blood flow was 2.78+/-0.47 l min(-1) for the 19 F rectilinear cannula versus 3.64+/-0.39 l min(-1) for the 18/36 F self-expanding cannula (p<0.01 for 18/36 F vs 19 F). At 1500 RPM, the venous line pressure was 18+/-8 mmHg for the 19F rectilinear cannula versus 19+/-5 mmHg for the 18/36 F self-expanding cannula. At 2500 RPM the venous line pressure accounted for -22+/-32 mmHg for the 19 F rectilinear cannula versus 2+/-5 mmHg for the 18/36 F self-expanding cannula. At 3500 RPM, the venous line pressure was -112+/-42 mmHg for the rectilinear cannula versus 28+/-7 mmHg for the 18/36 F self-expanding cannula (p<0.01 for 18 F/36 F vs 19 F). CONCLUSIONS: The negative pressure required to achieve adequate venous drainage with the self-expanding venous cannula accounts for approximately 31% of the pressure necessary with the 19 F rectilinear cannula. In addition, a pump flow of more than 4 l min(-1) can be achieved with the self-expanding design and a well-accepted negative inlet pressure for minimal blood trauma of less than 50 mmHg.

Temporary caval stenting improves venous drainage during cardiopulmonary bypass.

OBJECTIVES: Assess the benefit of temporary caval stenting for remote venous drainage during cardiopulmonary bypass (CPB). METHODS: Temporary caval stenting was realized in bovine experiments (65+/-6 kg) by the means of self-expanding (18F for insertion, 36F in situ) venous cannulas (Smartcanula LLC, Lausanne, Switzerland) with various lengths: 43 cm, 53 cm, 63 cm vs. a standard 28F wire armed cannula in trans-jugular fashion. Maximal blood flows were assessed for 20, 25 and 30 mmHg of driving pressure with a motorized table height adjustment system. In addition, the inferior caval diameters (just above its bifurcation) were measured in real time with intra-vascular ultrasound (IVUS). RESULTS: Venous drainage (flow in l/min) at 20 mmHg, 25 mmHg, and 30 mmHg drainage load was 3.5+/-0.5, 3.7+/-0.7 and 4.0+/-0.6 for the 28F standard vs. 4.1+/-0.7, 4.0+/-1.3 and 3.9+/-1.1 for the 36F smart 43 cm, vs. 5.0+/-0.7, 5.3+/-1.3 and 5.4+/-1.4 for the 36F smart 53 cm, vs. 5.2+/-0.5*, 5.6+/-1.1* and 5.8+/-1.0* for the 36F smart 63 cm. The inferior vena caval diameters at 30 mmHg were 13.5+/-4.8 mm for 28F standard, 11.1+/-3.6 for 36F smart 43 cm, 11.3+/-3.2 for 36F 53 cm, and 17.0+/-0.1* for 36F 63 cm (*P<0.05 for 28F standard vs. 36F smart 63 cm long) CONCLUSIONS: The 43 cm self-expanding 36F smartcanula outperforms the 28F standard wire armed cannula at low drainage pressures and without augmentation. Temporary caval stenting with long self-expanding venous cannulas provides even better drainage (+51%).

Routine use of self-expanding venous cannulas for cardiopulmonary bypass: benefits and pitfalls in 100 consecutive cases.

OBJECTIVE: Assess the performance of self-expanding venous cannulas for routine use in open-heart surgery. METHODS: Prospective study in 100 unselected consecutive patients undergoing open-heart surgery with either remote or central smart venous cannulation. RESULTS: The study focuses on the 76 consecutive adult patients (mean age 59.2+/-17.3 years; 60 males, 16 females) undergoing surgical procedures with total cardiopulmonary bypass for either valve procedures (42/76 patients=55.3%), ascending aorta and arch repair (20/76 patients=26.3%), coronary artery revascularization (13/76 patients=17.1%) or other procedures (11/76 patients=14.5%) with 14/76 patients (18.4%) undergoing redo surgery and 6/76 patients (7.9%) undergoing small access surgery. The mean pump flow achieved by gravity drainage alone accounted for 5.0+/-0.6l/min (=114% of target) in the entire study population (n=76) as compared to the calculated, theoretical pump flow of 4.4+/-0.5l/min (p<0.0001). For the femoral cannulation sub-group (n=35) pump flow achieved by gravity drainage alone accounted for 4.9+/-0.6l/min (=114% of target) as compared to the calculated theoretical pump flow of 4.3+/-0.4l/min (p<0.0001). The corresponding numbers for trans-subclavian cannulation (n=7) are 5.2+/-0.5l/min (111%) for the pump flow achieved by gravity drainage as compared to the theoretical target flow of 4.7+/-0.4l/min. For the central cannulation sub-group (n=34) mean flow achieved by gravity drainage with a self-expanding venous cannula accounted for 5.1+/-0.7l/min (=116% of target) as compared to the calculated theoretical flow of 4.4+/-0.6l/min (p<0.0001). CONCLUSION: Full or more than target flow was achieved in 97% of the patients studied undergoing CPB with self-expanding venous cannulas and gravity drainage. Remote venous cannulation with self-expanding cannulas provides similar flows as central cannulation. Augmentation of venous return is no longer necessary.