Publications by authors named "Reiner Koerfer"

109 Publications

Prototype Development of an Implantable Compliance Chamber for a Total Artificial Heart.

Artif Organs 2017 Feb 1;41(2):122-129. Epub 2016 Sep 1.

Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH-Aachen University, Aachen.

At our institute a total artificial heart is being developed. It is directly actuated by a linear drive in between two ventricles, which comprise membranes to separate the drive and blood flow. A compliance chamber (CC) is needed to reduce pressure peaks in the ventricles and to increase the pump capacity. Therefore, the movement of the membrane is supported by applying a negative pressure to the air volume inside the drive unit. This study presents the development of the implantable CC which is connected to the drive unit of the total artificial hearts (TAH). The anatomical fit of the CC is optimized by analyzing CT data and adapting the outer shape to ensure a proper fit. The pressure peaks are reduced by the additional volume and the flexible membrane of the CC. The validation measurements of change in pressure peaks and flow are performed using the complete TAH system connected to a custom mock circulation loop. Using the CC, the pressure peaks could be damped below 5 mm Hg in the operational range. The flow output was increased by up to 14.8% on the systemic side and 18.2% on the pulmonary side. The described implantable device can be used for upcoming chronic animal trials.
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http://dx.doi.org/10.1111/aor.12738DOI Listing
February 2017

Liver failure in total artificial heart therapy.

J Thorac Dis 2016 Jul;8(7):1546-9

Department of Cardiac Surgery, University Heart Center Graz, Medical University of Graz, Austria.

Background: Congestive hepatopathy (CH) and acute liver failure (ALF) are common among biventricular heart failure patients. We sought to evaluate the impact of total artificial heart (TAH) therapy on hepatic function and associated clinical outcomes.

Methods: A total of 31 patients received a Syncardia Total Artificial Heart. Preoperatively 17 patients exhibited normal liver function or mild hepatic derangements that were clinically insignificant and did not qualify as acute or chronic liver failure, 5 patients exhibited ALF and 9 various hepatic derangements owing to CH. Liver associated mortality and postoperative course of liver values were prospectively documented and retrospectively analyzed.

Results: Liver associated mortality in normal liver function, ALF and CH cases was 0%, 20% (P=0.03) and 44.4% (P=0.0008) respectively. 1/17 (5.8%) patients with a normal liver function developed an ALF, 4/5 (80%) patients with an ALF experienced a markedly improvement of hepatic function and 6/9 (66.6%) patients with CH a significant deterioration.

Conclusions: TAH therapy results in recovery of hepatic function in ALF cases. Patients with CH prior to surgery form a high risk group with increased liver associated mortality.
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http://dx.doi.org/10.21037/jtd.2016.05.81DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4958784PMC
July 2016

Applicability of cardiogoniometry as a non-invasive screening tool for the detection of graft vasculopathy in heart transplant recipients.

Interact Cardiovasc Thorac Surg 2016 12 1;23(6):976-978. Epub 2016 Aug 1.

Department of Cardiac Surgery, University Heart Center Graz, Medical University of Graz, Graz, Austria.

Currently available diagnostic modalities for the detection of graft vasculopathy following orthotopic heart transplantation are subject to various restrictions. We hypothesized that cardiogoniometry, a novel non-invasive diagnostic tool for the detection of atherosclerotic coronary vessel disease, is applicable in the graft vasculopathy setting. Cardiogoniometric results were obtained during routine follow-up in 49 consecutive, unselected heart transplant recipients and then retrospectively correlated blindly by an independent reader to recent angiographic findings. Sensitivity of cardiogoniometry was 100%, specificity 62.3%, positive predictive value 68.75%, negative predictive value 100%, negative likelihood ratio 0 and positive likelihood ratio 2.888. Cardiogoniometry is potentially applicable as an easy-to-perform, non-invasive screening tool predominantly for the exclusion but also for the detection of graft vasculopathy in heart transplant recipients.
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http://dx.doi.org/10.1093/icvts/ivw237DOI Listing
December 2016

Occult bleeding in left ventricular assist device recipients: It is the patient rather than the pump.

J Thorac Cardiovasc Surg 2016 Jul;152(1):289-90

Department for the Surgical Therapy of End-Stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, Duisburg, Germany.

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http://dx.doi.org/10.1016/j.jtcvs.2016.01.040DOI Listing
July 2016

Early Outcomes With Marginal Donor Hearts Compared With Left Ventricular Assist Device Support in Patients With Advanced Heart Failure: Could the Cardiac Allocation Score Be the Solution to the Dilemma of Therapy Selection?

Ann Thorac Surg 2016 Apr;101(4):1630

Department for the Surgical Therapy of End-Stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, Fahrner St 133-135, 47169 Duisburg, Germany.

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http://dx.doi.org/10.1016/j.athoracsur.2015.08.082DOI Listing
April 2016

Nocardiosis in Heart Transplant Recipients.

Heart Surg Forum 2015 Dec 14;18(6):E250-2. Epub 2015 Dec 14.

Heart and Vascular Institute, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania.

Nocardia has emerged as an important opportunistic pathogen, especially in organ transplant recipients. Heart transplant (HT) recipients initially had an especially high rate of Nocardia infection, but this could be reduced by the routine use of cyclosporine. Our objective was to clarify the prevalence and presentation of Nocardiosis in HT recipients in a retrospective cross-sectional analysis.
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http://dx.doi.org/10.1532/hsf.1372DOI Listing
December 2015

Speed modulation alone is not enough.

J Heart Lung Transplant 2016 Feb 29;35(2):260. Epub 2015 Oct 29.

Department for the Surgical Therapy of End-stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, Duisburg, Germany.

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http://dx.doi.org/10.1016/j.healun.2015.10.034DOI Listing
February 2016

Implantation technique of the 50-cm3 SynCardia Total Artificial Heart: does size make a difference?

Multimed Man Cardiothorac Surg 2015 5;2015. Epub 2015 Oct 5.

Department for the Surgical Therapy of End-Stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, Duisburg, Germany.

Despite downsizing, implantation technique of the 50-cm(3) SynCardia Total Artificial Heart and settings of the Companion driver remain unchanged. Owing to the absence of de-airing nipples, de-airing procedure is even more crucial and has to be performed carefully.
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http://dx.doi.org/10.1093/mmcts/mmv029DOI Listing
April 2016

Acute myocardial infarction complicated by cardiogenic shock: results of primary percutaneous coronary interventions are insufficient.

Eur J Cardiothorac Surg 2016 Apr 15;49(4):1298. Epub 2015 Sep 15.

Department for the Surgical Therapy of End-stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, Duisburg, Germany.

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http://dx.doi.org/10.1093/ejcts/ezv331DOI Listing
April 2016

Expanding Applicability of Total Artificial Heart Therapy: The 50-cc SynCardia Total Artificial Heart.

Ann Thorac Surg 2015 Sep;100(3):e55-7

Department for the Surgical Therapy of End-Stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, Duisburg, Germany.

The 50-cc SynCardia total artificial heart is designed to facilitate orthotopic replacement of the native ventricles in patients with a body surface area below 1.7 m(2) in need of long-term circulatory support as a result of end-stage biventricular heart failure. We describe the implementation of this technology in a female patient with irreversible cardiogenic shock on the grounds of acute myocardial infarction and chronic ischemic cardiomyopathy.
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http://dx.doi.org/10.1016/j.athoracsur.2015.04.010DOI Listing
September 2015

Delayed sternal closure after total artificial heart implantation.

J Thorac Cardiovasc Surg 2015 Aug 7;150(2):417-8. Epub 2015 May 7.

Department for the Surgical Therapy of End-stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, Duisburg, Germany.

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http://dx.doi.org/10.1016/j.jtcvs.2015.04.057DOI Listing
August 2015

Percutaneous dilatational tracheostomy following total artificial heart implantation.

Interact Cardiovasc Thorac Surg 2015 Jul 25;21(1):117-8. Epub 2015 Mar 25.

Department for the Surgical Therapy of End-stage Heart Failure and Mechanical Circulatory Support, Heart- and Vascular Center Duisburg, Duisburg, Germany.

Coagulation disorders and an immune-altered state are common among total artificial heart patients. In this context, we sought to evaluate the safety of percutaneous dilatational tracheostomy in cases of prolonged need for mechanical ventilatory support. We retrospectively analysed the charts of 11 total artificial heart patients who received percutaneous dilatational tracheostomy. We focused on early and late complications. We observed no major complications and no procedure-related deaths. Early minor complications included venous oozing (45.4%) and one case of local infection. Late complications, including subglottic stenosis, stomal infection or infections of the lower respiratory tract, were not observed. In conclusion, percutaneous dilatational tracheostomy in total artificial heart patients is safe. Considering the well-known benefits of early tracheotomy over prolonged translaryngeal intubation, we advocate early timing of therapy in cases of prolonged mechanical ventilation.
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http://dx.doi.org/10.1093/icvts/ivv071DOI Listing
July 2015

Diagnosis of obstructive coronary artery disease by cardiogoniometry: a field test in a real-life setting.

J Electrocardiol 2015 May-Jun;48(3):420-2. Epub 2015 Jan 29.

Department for the Surgical Therapy of End-Stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duiburg, Duisburg, Germany.

Cardiogoniometry is an electrocardiographic and vectorcardiographic method utilizing computer-assisted analysis of cardiac potentials focusing on T-wave abnormalities resulting from myocardial malperfusion. We describe a case of diagnosis of obstructive coronary artery disease with this method and discuss the possible implications for the clinical setting.
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http://dx.doi.org/10.1016/j.jelectrocard.2015.01.012DOI Listing
February 2016

Paving the way for destination therapy of end-stage biventricular heart failure: the ReinHeart total artificial heart concept.

Eur J Cardiothorac Surg 2014 Dec 18;46(6):935-6. Epub 2014 Sep 18.

Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany.

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http://dx.doi.org/10.1093/ejcts/ezu317DOI Listing
December 2014

System overview of the fully implantable destination therapy--ReinHeart-total artificial heart.

Eur J Cardiothorac Surg 2015 Jan 18;47(1):80-6. Epub 2014 Sep 18.

Department for the Surgical Therapy of end-stage Heart Failure and Mechanical Circulatory Support, Heart- and Vascular Center Duisburg, Duisburg, Germany.

Objectives: Owing to the lack of suitable allografts, the demand for long-term mechanical circulatory support in patients with biventricular end-stage heart failure is rising. Currently available Total Artificial Heart (TAH) systems consist of pump units with only limited durability, percutaneous tubes and bulky external equipment that limit the quality of life. Therefore we are focusing on the development of a fully implantable, highly durable destination therapy total artificial heart.

Methods: The ReinHeart-TAH system consists of a passively filling pump unit driven by a low-wear linear drive between two artificial ventricles, an implantable control unit and a compliance chamber. The TAH is powered by a transcutaneous energy transmission system. The flow distribution inside the ventricles was analysed by fluid structure interaction simulation and particle image velocimetry measurements. Along with durability tests, the hydrodynamic performance and flow balance capability were evaluated in a mock circulation loop. Animal trials are ongoing.

Results: Based on fluid structure interaction simulation and particle image velocimetry, blood stagnation areas have been significantly reduced. In the mock circulation loop the ReinHeart-TAH generated a cardiac output of 5 l/min at an operating frequency of 120 bpm and an aortic pressure of 120/80 mmHg. The highly effective preload sensitivity of the passively filling ventricles allowed the sensorless integration of the Frank Starling mechanism. The ReinHeart-TAH effectively replaced the native heart's function in animals for up to 2 days.

Conclusions: In vitro and in vivo testing showed a safe and effective function of the ReinHeart-TAH system. This has the potential to become an alternative to transplantation. However, before a first-in-man implant, chronic animal trials still have to be completed.
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http://dx.doi.org/10.1093/ejcts/ezu321DOI Listing
January 2015

Normothermic ex vivo allograft blood perfusion in clinical heart transplantation.

Heart Surg Forum 2014 Jun;17(3):E141-5

Departmant of Heart and Vascular Surgery, Division for Surgical Therapy of End-Stage Heart Failure and Artificial Heart Support, Evangelisches und Johanniter Klinikum Niederrhein, Duisburg, NRW, Germany.

Background: Cold ischemia associated with cold static storage is an independent risk factor for primary allograft failure and survival of patients after orthotopic heart transplantation. The effects of normothermic ex vivo allograft blood perfusion on outcomes after orthotopic heart transplantation compared to cold static storage have been studied.

Methods: In this prospective, nonrandomized, single-institutional clinical study, normothermic ex vivo allograft blood perfusion has been performed using an organ care system (OCS) (TransMedics, Andover, MA, USA). Included were consecutive adult transplantation patients who received an orthotopic heart transplantation (oHTx) without a history of any organ transplantation, in the absence of a congenital heart disorder as an underlying disease and not being in need of a combined heart-lung transplantation. Furthermore, patients with fixed pulmonary hypertension, ventilator dependency, chronic renal failure, or panel reactive antibodies >20% and positive T-cell cross-matching were excluded. Inclusion criteria for donor hearts was age of <55 years, systolic blood pressure >85 mmHg at the time of final heart assessment under moderate inotropic support, heart rate of <120 bpm at the time of explantation, and left ventricular ejection fraction >40% assessed by an transcutaneous echo/Doppler study with the absence of gross wall motion abnormalities, absence of left ventricular hypertrophy, and absence of valve abnormalities. Donor hearts which were conventionally cold stored with histidine-tryptophan-ketoglutarate solution (Custodiol; Koehler Chemie, Ansbach, Germany) constituted the control group. The primary end point was the recipients' survival at 30 days and 1 and 2 years after their heart transplantation. Secondary end points were primary and chronic allograft failure, noncardiac complications, and length of hospital stay.

Results: Over a 2-year period (January 2006 to July 2008), 159 adult cardiac allografts were transplanted. Twenty-nine were assigned for normothermic ex vivo allograft blood perfusion and 130 for cold static storage with HTK solution. Cumulative survival rates at 30 days and 1 and 2 years were 96%, 89%, and 89%, respectively, whereas in the cold static storage group survival after oHTx was 95%, 81%, and 79%. Primary graft failure was less frequent in the recipients of an oHTx who received a donor heart which had been preserved with normothermic ex vivo allograft blood perfusion using an OCS (6.89% versus 15.3%; P = .20). Episodes of severe acute rejection (23% versus 17.2%; P = .73), as well as, cases of acute renal failure requiring haemodialysis (25.3% versus 10%; P = .05) were more frequent diagnosed among recipients of a donor heart which had been preserved using the cold static storage. The length of hospital stay did not differ (26 days versus 28 days; P = .80) in both groups.

Conclusions: Normothermic ex vivo allograft blood perfusion in adult clinical orthotopic heart transplantation contributes to better outcomes after transplantation in regard to recipient survival, incidence of primary graft dysfunction, and incidence of acute rejection.
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http://dx.doi.org/10.1532/HSF98.2014332DOI Listing
June 2014

B-type natriuretic peptide therapy in total artificial heart implantation: renal effects with early initiation.

J Heart Lung Transplant 2014 Jun 12;33(6):662-3. Epub 2014 Mar 12.

Heart and Vascular Center Duisburg, Department for the Surgical Therapy of End-stage, Heart Failure and Mechanical Circulatory Support, Duisburg, Germany.

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http://dx.doi.org/10.1016/j.healun.2014.03.001DOI Listing
June 2014

A first step beyond traditional boundaries: destination therapy with the SynCardia total artificial heart.

Interact Cardiovasc Thorac Surg 2014 Jun 14;18(6):855-6. Epub 2014 Mar 14.

Department of Surgical Therapy of End-stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, Duisburg, Germany.

The SynCardia total artificial heart is currently used as a bridge to transplantation therapy in cases of irreversible, acute or chronic, biventricular heart failure. We describe the implementation of this technology in the context of destination therapy in a patient with an end-stage heart failure on grounds of primary amyloidosis.
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http://dx.doi.org/10.1093/icvts/ivu065DOI Listing
June 2014

Home discharge and out-of-hospital follow-up of total artificial heart patients supported by a portable driver system.

ASAIO J 2014 Mar-Apr;60(2):148-53

From the *Penn State Milton S. Hershey Medical Center, Heart and Vascular Institute, Hershey, PA; †Heart and Diabetes Center North Rhine-Westphalia, Department of Thoracic and Cardiovascular Surgery, Bad Oeynhausen, Germany; ‡Berlin Heart, Berlin, Germany; and §Sarver Heart Center, University of Arizona, Tucson, AZ.

To enhance ambulation and facilitate hospital discharge of total artificial heart (TAH)-supported patients, we adapted a mobile ventricular assistance device (VAD) driver (Excor) for TAH use and report on the performance of Excor-driven TAH patients discharged home. Ten patients stabilized on a TAH, driven by the CSS ("Circulatory Support System"), were progressively switched over to the Excor in hospital over 14 days as a pilot, with daily hemodynamics and laboratory parameters measured. Twenty-two stable TAH patients were subsequently placed on the Excor, trained, and discharged home. Clinical and hemodynamic parameters were followed. All pilot study patients were clinically stable on the Excor, with no decrease in TAH output noted (6.3 + 0.3 L/min [day 1] vs. 5.8 + 0.2 L/min [day 14], p = 0.174), with a trend suggesting improvement of both hepatic and renal function. Twenty-two TAH patients were subsequently successfully discharged home on the portable driver and were supported out of hospital for up to 598 days (range, 2-598; mean = 179 ± 140 days), remaining ambulatory, New York Heart Association (NYHA) class I or II, and free of readmission for 88.5% of the time of support. TAH patients may be effectively and safely supported by a mobile drive system. As such, the utility of the TAH may be extended to support patients beyond the hospital, at home, with overall ambulatory freedom.
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http://dx.doi.org/10.1097/MAT.0000000000000046DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3942352PMC
October 2014

A monitoring and physiological control system for determining aortic valve closing with a ventricular assist device.

Eur J Cardiothorac Surg 2014 Sep 4;46(3):356-60; discussion 360. Epub 2014 Feb 4.

Department for the Surgical Therapy of End-stage Heart Failure and Mechanical Circulatory Support, Heart- and Vascular Center Duisburg, Duisburg, Germany.

Objectives: Real-time monitoring of the aortic valve function and the loading state of the left ventricle (LV) during mechanical circulatory support is essential. Therefore, we developed a system that determines accurately the aortic valve closing moment based on integrals derived from the pump inlet pressure and the pump power [pressure-power area (PPA)].

Methods: A Deltastream diagonal pump was implanted in 10 healthy Rhoen sheep. Changes in ventricular volume and pressure in different assist levels were measured by a conductance catheter placed in the LV and were correlated with intrinsic pump signals, motor power, voltage and current. Measurements were obtained in the state of normal as well as decreased left ventricular contractility induced by β-blockers.

Results: Complete datasets were obtained in seven animals. The PPA-feedback signal reached its maximum at the speed of aortic valve closing. This was validated by pressure-volume (PV)-catheter measurements both at the baseline and in the state of decreased contractility. In both cases, zero-crossing occurred at the point of aortic valve closing speed.

Conclusions: With this trial, we deliver the experimental basis for the development of an automatic feedback controller that would allow periodic speed changes in accordance with the loading state of the native ventricle and the opening state of the aortic valve. This would deliver real-time data to treating physicians and enable the establishment of a standard weaning protocol.
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http://dx.doi.org/10.1093/ejcts/ezu006DOI Listing
September 2014

Repair of left ventricular driveline tear in a SynCardia-total artificial heart patient.

J Cardiothorac Surg 2014 Jan 7;9. Epub 2014 Jan 7.

Department for the Surgical Therapy of End-stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, Fahrner street 135-137, Duisburg 47169, Germany.

We report the case of a 64-year old Caucasian male patient with a tear of the left ventricular driveline just above the driveline-air tube junction. We describe the repair technique and the necessary set of tools.
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http://dx.doi.org/10.1186/1749-8090-9-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3892055PMC
January 2014

Image based evaluation of mediastinal constraints for the development of a pulsatile total artificial heart.

Biomed Eng Online 2013 Aug 14;12:81. Epub 2013 Aug 14.

Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH-Aachen University, Aachen, Germany.

Background: Good anatomical compatibility is an important aspect in the development of cardiovascular implants. This work analyzes the interaction of the pump unit of an electrically driven pulsatile Total Artificial Heart (TAH) and the mediastinum. For an adequate compliance, both overall dimensions and alignment of inlets and outlets must be matched.

Methods: Cross-sectional medical image data of 27 individuals, including male and female patients suffering from end stage heart failure, was segmented and reconstructed to three dimensional (3D) surface models. Dimensions and orientations of relevant structures were identified and analyzed. The TAH surface model was virtually placed in orthotopic position and aligned with atrioventricular valves and big vessels. Additionally seven conventional cadaver studies were performed to validate different pump chamber designs based on virtual findings. Thereby 3D-coordinates were captured and introduced to the virtual environment to allow quantitative comparison between different individuals.

Results: Spatial parameters varied more in male patients with higher values if heart failure persists. Good correlation of the virtual analysis both to literature data and conventional cadaver studies could be shown. The full data of the 27 individuals as well as the summarized values found in literature are enclosed in the appendix. By superimposing the TAH-volume model to the anatomy, various misalignments were found and the TAH-design was adjusted.

Conclusions: Virtual fitting allows implant design adjustments in realistic anatomy which has not been influenced by thoracotomy. Higher numbers of relevant individuals can be reasonably investigated in the virtual environment and quantitatively correlated. Using this approach, conventional cadaver studies can be significantly reduced but not obviated, due to the unavailable haptic feedback and immobility of potentially compressed structures.
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http://dx.doi.org/10.1186/1475-925X-12-81DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3751639PMC
August 2013

Veno-venous extracorporeal membrane oxygenation with a bicaval dual-lumen catheter in a SynCardia total artificial heart patient.

J Cardiothorac Surg 2013 Aug 5;8:179. Epub 2013 Aug 5.

We report the case of a 55 years old caucasian male patient with cardiogenic shock due to an extended myocardial infarction who underwent SynCardia Total Artificial Heart implantation and veno-venous extracorporeal membrane oxygenation with a bicaval dual-lumen cannula for the treatment of adult respiratory distress syndrome.
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http://dx.doi.org/10.1186/1749-8090-8-179DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3737105PMC
August 2013

Beneficial aspects of real time flow measurements for the management of acute right ventricular heart failure following continuous flow ventricular assist device implantation.

J Cardiothorac Surg 2012 Nov 12;7:119. Epub 2012 Nov 12.

Department for the Surgical Management of End-stage Heart Failure and Mechanical Circulatory Support, Heart and Vascular Center Duisburg, 47169 Duisburg, Germany.

Background: Optimal management of acute right heart failure following the implantation of a left ventricular assist device requires a reliable estimation of left ventricular preload and contractility. This is possible by real-time pump blood flow measurements.

Clinical Case: We performed implantation of a continuous flow left ventricular assist device in a 66 years old female patient with an end-stage heart failure on the grounds of a dilated cardiomyopathy. Real-time pump blood flow was directly measured by an ultrasonic flow probe placed around the outflow graft.

Diagnosis: The progressive decline of real time flow and the loss of pulsatility were associated with an increase of central venous pressure, inotropic therapy and progressive renal failure suggesting the presence of an acute right heart failure. Diagnosis was validated by echocardiography and thermodilution measurements.

Treatment: Temporary mechanical circulatory support of the right ventricle was successfully performed. Real time flow measurement proved to be a useful tool for the diagnosis and ultimately for the management of right heart failure including the weaning from extracorporeal membrane oxygenation.
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http://dx.doi.org/10.1186/1749-8090-7-119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3514258PMC
November 2012

Results of the European clinical trial of Arrow CorAide left ventricular assist system.

Artif Organs 2013 Feb 9;37(2):121-7. Epub 2012 Oct 9.

Heart Center North Rhine-Westphalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany.

The aim of this study was to evaluate the safety and performance of the Arrow CorAide left ventricular assist system (LVAS) (Arrow International, Reading, PA, USA), a continuous-flow left ventricular assist device, as bridge to transplantation or recovery as well as destination therapy in patients with New York Heart Association (NYHA) class IV heart failure. Twenty-one patients were implanted with the CorAide LVAS between February 2005 and February 2006 in a prospective, multicenter, nonrandomized trial. Seventeen patients (81%) survived to >180 days or to transplantation. The cumulative time on device was 16.58 patient years (range 23-796 days, median 192 days). No intraoperative technical issues were observed at the time of implantation. Of the 21 implants, nine patients died on device, two were converted to other devices, and 10 were transplanted. Three patient deaths were attributed to pump polymer coating delamination. Postmortem device inspection determined delamination of the polymer coating on the pump's internal surface to be the cause of the late hemolysis and sudden fatal pump stops. No embolic or driveline infection event was recorded. The automatic flow control algorithm functioned reliably throughout the trial. Primary performance trial endpoint was achieved with 81% survival to 180 days or transplantation. Delamination of the polymer coating on the internal surface of the pump with resultant hemolysis and pump stops was the sole major device event in this trial. Elimination of the polymer coating and replacement with an amorphous carbon coating has resolved this in preclinical testing, prior to initiation of further clinical testing of this device.
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http://dx.doi.org/10.1111/j.1525-1594.2012.01539.xDOI Listing
February 2013

Extracorporeal life support in pediatric cardiac dysfunction.

J Cardiothorac Surg 2010 Nov 17;5:112. Epub 2010 Nov 17.

Department of Thoracic and Cardiovascular Surgery, University of Göttingen, Göttingen, Germany.

Background: Low cardiac output (LCO) after corrective surgery remains a serious complication in pediatric congenital heart diseases (CHD). In the case of refractory LCO, extra corporeal life support (ECLS) extra corporeal membrane oxygenation (ECMO) or ventricle assist devices (VAD) is the final therapeutic option. In the present study we have reviewed the outcomes of pediatric patients after corrective surgery necessitating ECLS and compared outcomes with pediatric patients necessitating ECLS because of dilatated cardiomyopathy (DCM).

Methods: A retrospective single-centre cohort study was evaluated in pediatric patients, between 1991 and 2008, that required ECLS. A total of 48 patients received ECLS, of which 23 were male and 25 female. The indications for ECLS included CHD in 32 patients and DCM in 16 patients.

Results: The mean age was 1.2 ± 3.9 years for CHD patients and 10.4 ± 5.8 years for DCM patients. Twenty-six patients received ECMO and 22 patients received VAD. A total of 15 patients out of 48 survived, 8 were discharged after myocardial recovery and 7 were discharged after successful heart transplantation. The overall mortality in patients with extracorporeal life support was 68%.

Conclusion: Although the use of ECLS shows a significantly high mortality rate it remains the ultimate chance for children. For better results, ECLS should be initiated in the operating room or shortly thereafter. Bridge to heart transplantation should be considered if there is no improvement in cardiac function to avoid irreversible multiorgan failure (MFO).
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http://dx.doi.org/10.1186/1749-8090-5-112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2993705PMC
November 2010

Intra-abdominal hypertension due to heparin - induced retroperitoneal hematoma in patients with ventricle assist devices: report of four cases and review of the literature.

J Cardiothorac Surg 2010 Nov 10;5:108. Epub 2010 Nov 10.

Herzzentrum Essen, Herwarthstrasse 100, 45138 Essen, Germany.

Introduction: Elevated intra-abdominal pressure (IAP) has been identified as a cascade of pathophysiologic changes leading in end-organ failure due to decreasing compliance of the abdomen and the development of abdomen compartment syndrome (ACS). Spontaneous retroperitoneal hematoma (SRH) is a rare clinical entity seen almost exclusively in association with anticoagulation states, coagulopathies and hemodialysis; that may cause ACS among patients in the intensive care unit (ICU) and if treated inappropriately represents a high mortality rate.

Case Presentation: We report four patients (a 36-year-old Caucasian female, a 59-year-old White-Asian male, a 64-year-old Caucasian female and a 61-year-old Caucasian female) that developed an intra-abdominal hypertension due to heparin-induced retroperitoneal hematomas after implantation of ventricular assist devices because of heart failure. Three of the patients presented with dyspnea at rest, fatigue, pleura effusions in chest XR and increased heart rate although b-blocker therapy. A 36-year old female (the forth patient) presented with sudden, severe shortness of breath at rest, 10 days after an "acute bronchitis". At the time of the event in all cases international normalized ratio (INR) was <3.5 and partial thromboplastin time <65 sec. The patients were treated surgically, the large hematomas were evacuated and the systemic manifestations of the syndrome were reversed.

Conclusion: Identifying patients in the ICU at risk for developing ACS with constant surveillance can lead to prevention. ACS is the natural progression of pressure-induced end-organ changes and develops if IAP is not recognized and treated in a timely manner. Failure to recognize and appropriately treat ACS is fatal while timely intervention - if indicated - is associated with improvements in organ function and patient survival. Means for surgical decision making are based on clinical indicators of adverse physiology, rather than on a single measured parameter.
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http://dx.doi.org/10.1186/1749-8090-5-108DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2992055PMC
November 2010

Efficacy and safety of very low-dose self-management of oral anticoagulation in patients with mechanical heart valve replacement.

Ann Thorac Surg 2010 Nov;90(5):1487-93

Clinic for Thoracic and Cardiovascular Surgery, Heart Center North Rhine-Westphalia, Ruhr University Bochum, Bad Oeynhausen, Germany.

Background: Self-management improves oral anticoagulation control. Here we provide data of a preplanned interim analysis of very low-dose early self-controlled anticoagulation.

Methods: In a prospective, randomized, multicenter trial, 1,137 patients performed low-dose international normalized ratio (INR) self-management with a target INR range of 1.8. to 2.8 for aortic valve replacement recipients and 2.5 to 3.5 for mitral or double valve replacement recipients for the first six postoperative months. Thereafter, 379 patients continued to achieve the aforementioned INR target range (LOW group), whereas the INR target value was set at 2.0 (range, 1.6 to 2.1) for the remaining patients with aortic valve replacement and 2.3 (range, 2.0 to 2.5) for the remaining patients with mitral valve or double valve replacement. One half of this latter group had to check their INR values once a week (VL1 group) the other half twice a week (VL2 group). Patients were followed up for 24 months.

Results: Beyond study month six, the incidence of thromboembolic events that required hospital admission was 0.58%, 0.0%, and 0.58% in the LOW, VL1, and VL2 groups, respectively (p = 0.368). The incidence of bleeding events per patient-year was 1.16%, 1.07%, and 0.58% in the LOW, VL1, and VL2 groups, respectively (p = 0.665). Mortality rate did not differ among study groups.

Conclusions: Data demonstrate the efficacy and safety of very low-dose INR self-management.
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http://dx.doi.org/10.1016/j.athoracsur.2010.06.069DOI Listing
November 2010

Thrombosis of the ascending aorta during mechanical circulatory support in a patient with cardiogenic shock.

Interact Cardiovasc Thorac Surg 2010 Oct 23;11(4):510-1. Epub 2010 Jul 23.

Department of Thoracic and Cardiovascular Medicine, Heart and Diabetes Center North-Rhine Westphalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany.

Cardiogenic shock after percutaneous coronary intervention (PCI) is a life-threatening complication and is most often related to abrupt vessel closure. We present the case of a patient who developed cardiogenic shock after PCI and was supported with intra-aortic balloon counterpulsation and the Levitronix CentriMag short-term mechanical circulatory support. He was evaluated for implantation of a ventricular assist device as bridge-to-transplantation. Preoperative transesophageal echocardiography revealed a massive thrombus of the aortic root and ascending aorta despite optimal anticoagulation regimen. The patient succumbed due to multiorgan failure.
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http://dx.doi.org/10.1510/icvts.2010.240689DOI Listing
October 2010