[Show abstract][Hide abstract] ABSTRACT: Cerebral thromboembolism builds the Achilles heel for patients on left ventricular support (LVAD). Thrombolytic therapy is usually contraindicated considering the increased risk of intracranial hemorrhage in LVAD patients under therapeutic oral anticoagulation with concomitant platelet inhibition. We report on an alternative approach to this dilemma. On day 1091 of LVAD support (INCOR(R) Berlin Heart) a 69-year-old male patient was admitted to a rural hospital unconscious with a left sided hemiplegia. Cerebral computed tomography (cCT) with CT-angiography revealed a thrombembolic distal basilar artery occlusion. The patient was immediately transported to our medical center, where an interventional thrombectomy restored full patency of the vessel. The patient recovered without neurological sequelae within days. This case highlights the fact that patients on LVAD support with a neurological event should be immediately transferred to a neurovascular center for appropriate treatment including a neurointervention.
[Show abstract][Hide abstract] ABSTRACT: Objectives:
We demonstrate a multislice computed tomography (MSCT)-based method to calculate the prediction of the so-called 'line of perpendicularity' (LOP) and the 'implanter's views' (IVs) for transcatheter aortic valve implantation (TAVI) procedures. The LOP represents all possible angiographic angulations that result in an orthogonal view to the aortic annulus plane. The IVs allow visual confirmation of correct implantation planes, and are crucial for the commissural aligned implantation of second-generation TAVI prostheses.
The LOP and IVs of 335 concomitant patients were prospectively analysed using multiple plane reconstruction (MPR) of the patient's MSCT scans. Exclusion criteria were bicuspid valves (n = 18) and valve-in-valve TAVI (n = 15). In the MPRs, the aortic cusps' lowest points were marked. With the marker's three-dimensional coordinates, the graph of the LOP with the IVs was calculated and plotted using vector mathematics. In the last 244 cases, the IV with the right coronary cusp in front was chosen for the first aortic root angiogram of the TAVI procedure. The finally used angulation was confirmed by aortic angiogram prior to the valve implantation. Solid angle differences that show the combined left anterior oblique/right anterior oblique and cranio/caudal movement of the C-arm allow quantification of corrections as well as demonstrate interindividual variations.
There is a broad interindividual variation of the aortic valve's topology with solid angle variations of up to 74°. The shape of the LOPs is extremely varying, especially regarding the slope of the curve that indicates differences in valve orientations. Among the 244 patients for whom we used the prediction for the procedure, the first angiogram was considered perfect for implantation without further corrections in 97% (n = 237) of them. In case of the 7 patients with subsequent corrections, the mean solid angle between the prediction and the final angiogram prior to implantation was 6.2° (±5°); the largest correction was 14°.
Prediction of the implantation plane by analysing the patient's MSCT is highly reliable in achieving an adequate view of the aortic annulus in TAVI. The analysis of LOPs showed the large interindividual differences that permit using a standard implantation plane. Therefore, we strongly recommend determining the LOP and IVs during the patient's screening process in each single TAVI case.
European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 03/2015; DOI:10.1093/ejcts/ezv095 · 3.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Anti-endothelial cell antibodies (AECA) may be involved in the development of heart allograft rejection. Its detection might be a cheap and noninvasive method to identify high-risk patients. An indirect immunofluorescence method on human umbilical vein endothelial cells was used to investigate the presence of AECAs in 260 pre- and post-transplant serum samples sequentially collected from 34 patients within the first year after heart transplantation (HTX). The presence of AECAs before (23.5 %) and early after HTX (14.7 %) was associated with a significantly increased risk of early acute rejection (75 and 60 %, respectively) compared to 33 % in AECA-negative patients (p = 0.049). Moreover, rejections from AECA-positive patients were more severe (p = 0.057) with a significantly increased incidence of multiple (p = 0.025). The mean number of the sum of rejection episodes was significantly higher in AECA-positive patients (p ≤ 0.05). Patients free of AECAs mainly received mycophenolate mofetil as primary immunosuppression (p = 0.067). Nevertheless, the presence of AECAs did not affect long-term outcome and mortality of HTX patients. Despite a low number of patient samples, the detection of AECAs before and early after HTX could be used as a biomarker for an increased risk of early acute rejection in high-risk patients. This easy method might be a valuable tool to support screening procedures to improve individualized immunosuppressive therapy.
Heart and Vessels 03/2015; DOI:10.1007/s00380-015-0666-0 · 2.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Technical complications are a known hazard in veno-venous extracorporeal membrane oxygenation (vvECMO). Identifying these complications and predictive factors indicating a developing system-exchange was the goal of the study.
Retrospective study on prospectively collected data of technical complications including 265 adult patients (Regensburg ECMO Registry, 2009-2013) with acute respiratory failure treated with vvECMO. Alterations in blood flow resistance, gas transfer capability, hemolysis, coagulation and hemostasis parameters were evaluated in conjunction with a system-exchange in all patients with at least one exchange (n = 83).
Values presented as median (interquartile range). Patient age was 50(36-60) years, the SOFA score 11(8-14.3) and the Murray lung injury Score 3.33(3.3-3.7). Cumulative ECMO support time 3411 days, 9(6-15) days per patient. Mechanical failure of the blood pump (n = 5), MO (n = 2) or cannula (n = 1) accounted for 10% of the exchanges. Acute clot formation within the pump head (visible clots, increase in plasma free hemoglobin (frHb), serum lactate dehydrogenase (LDH), n = 13) and MO (increase in pressure drop across the MO, n = 16) required an urgent system-exchange, of which nearly 50% could be foreseen by measuring the parameters mentioned below. Reasons for an elective system-exchange were worsening of gas transfer capability (n = 10) and device-related coagulation disorders (n = 32), either local fibrinolysis in the MO due to clot formation (increased D-dimers [DD]), decreased platelet count; n = 24), or device-induced hyperfibrinolysis (increased DD, decreased fibrinogen [FG], decreased platelet count, diffuse bleeding tendency; n = 8), which could be reversed after system-exchange. Four MOs were exchanged due to suspicion of infection.
The majority of ECMO system-exchanges could be predicted by regular inspection of the complete ECMO circuit, evaluation of gas exchange, pressure drop across the MO and laboratory parameters (DD, FG, platelets, LDH, frHb). These parameters should be monitored in the daily routine to reduce the risk of unexpected ECMO failure.
PLoS ONE 12/2014; 9(12):e112316. DOI:10.1371/journal.pone.0112316 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Patients with left ventricular assist devices (LVADs) who develop stage IV sacral pressure sores (SPS) have an increased procedural risk. We present the complications, including severe intra- and postoperative bleeding, diarrhea with metabolic acidosis, volume loss and acute on chronic renal failure, flap dehiscence and late LVAD outflow cannula thrombosis, in a 54-year-old male who underwent diverting ileostomy (DI) and subsequent fasciocutaneous flap (FCF) surgery for stage IV SPS while supported with an LVAD. Our experience suggests that, despite continuous heparinization, life-threatening thrombotic complications, such as device clotting, can occur. Therefore, the benefit of intervention has to outweigh the risk of bleeding, which should be managed with meticulous surgical technique and substitution of red blood cells rather than the reversal of heparinization or the substitution of clotting factors. Continuation of double anti-platelet therapy should also be considered.
[Show abstract][Hide abstract] ABSTRACT: Purpose:
Polymethylpentene membrane oxygenators used in venovenous extracorporeal membrane oxygenation (vvECMO) differ in their physical characteristics. The aim of the study was to analyze the gas transfer capability of different ECMO systems in clinical practice, as the choice of the appropriate system may be influenced by the needs of the patient.
Retrospective study on prospectively collected data of adults with severe respiratory failure requiring vvECMO support (Regensburg ECMO Registry, 2009-2013). Oxygen (O2) transfer and carbon dioxide (CO2) elimination of four different ECMO systems (PLS system, n = 163; Cardiohelp system (CH), n = 59, Maquet Cardiopulmonary, Rastatt, Germany; Hilite 7000 LT system, n = 56, Medos Medizintechnik, Stolberg, Germany; ECC.05 system, n = 39, Sorin Group, Mirandola (MO), Italy) were analyzed.
Gas transfer depended on type of ECMO system, blood flow, and gas flow (p ≤ 0.05, each). CO2 removal is dependent on sweep gas flow and blood flow, with higher blood flow and/or gas flow eliminating more CO2 (p ≤ 0.001). CO2 elimination capacity was highest with the PLS system (p ≤ 0.001). O2 transfer at blood flow rates below 3 l/min depended on blood flow, at higher blood flow rates on blood flow and gas flow. The system with the smallest gas exchange surface (ECC.05 system) was least effective in O2 transfer, but in terms of the gas exchange surface was the most effective.
Our analysis suggests that patients with severe hypoxemia and need for high flow ECMO benefit more from the PLS/CH or Hilite 7000 LT system. The ECC.05 system is advisable for patients with moderate hypoxemia and/or hypercapnia.
Intensive Care Medicine 10/2014; DOI:10.1007/s00134-014-3489-z · 7.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives:
Re-exploration after cardiac surgery remains a frequent complication with adverse outcomes. The aim of this study was to evaluate the impact of timing and indication of re-exploration on outcome.
A retrospective, observational study on a cohort of 209 patients, who underwent re-exploration after cardiac surgery between January 2005 and December 2011, was performed. The cohort was matched for age, gender, and procedure with patients who were not re-explored during the same period.
The intraoperative and postoperative transfusion requirements were higher in the re-exploration group (p < 0.01). Patients in the re-exploration group had significantly higher incidences of postoperative acute renal injury (10.0 vs. 3.3%), sternal wound (9.1 vs. 2.4%) and pulmonary (13.4 vs. 4.3%) infections, longer ventilation time (22 [range, 14-52] vs. 12 [range, 9-16] hours) and intensive care unit stay (5 [range, 3-7] vs. 2 [range, 2-4] days), and higher mortality rate (9.6 vs. 3.3%). However, the multivariate logistic regression analysis demonstrated that not the re-exploration itself, but the deleterious effects of re-exploration (blood loss and transfusion requirement) were independent risk factors for mortality. Mortality was 5.3% for patients who were re-explored within the first 12 hours and 20.3% for patients who were re-explored after 12 hours (p = 0.003). Mortality was 3.6% for patients with bleeding and 31.4% for patients with cardiac tamponade for indication of re-exploration (p < 0.001).
This study suggests that re-exploration after cardiac surgery is associated with increased mortality and morbidity. Patients with delayed re-exploration and suffering from cardiac tamponade have adverse outcome.
The Thoracic and Cardiovascular Surgeon 09/2014; 63(01). DOI:10.1055/s-0034-1390154 · 0.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Objective of this study was to evaluate the impact of age on comparative early outcomes after coronary artery bypass graft surgery (CABG) with minimized (MECC) and conventional extracorporeal circulation (CECC).
A retrospective age-, gender- and operation-matched cohort analysis between January 2005 and December 2010 with a total of 2274 patients undergoing CABG with MECC (n = 1137; 50%) or CECC was performed. Patients were stratified into 4 groups according to age: <59 years, 60–69 years, 70–79 years, and 80 years of age or older. Outcomes were compared within each age group. Patients with preoperative dialysis were excluded from analysis. Primary endpoint was 30-day mortality.
Patients treated with CECC had a significantly higher mean logistic EuroSCORE (6.3% vs. 5.0%; p < 0.001), a slightly lower rate of preoperative myocardial infarction (46% vs. 51%; p = 0.01) and a higher rate of impaired renal function (eGFR < 60 mL/min/1.73 m2: 24% vs. 20%; p = 0.01) compared to MECC-patients. Left internal mammary artery was significantly used more often in MECC patients (93% vs. 86%; p < 0.001). Cardiopulmonary bypass and aortic-cross clamping time were significantly lower in the MECC group (p < 0.001). Overall 30-day mortality was significantly higher in patients treated with CECC (4.4% vs. 2.2%; p = 0.002). Within the different age groups mortality rates were not significantly different except for patients aged 60–69 years (4.5% vs. 1.8%; p = 0.03). Postoperative requirement of renal replacement therapy (4% vs. 2.2%; p = 0.01), respiratory insufficiency (9.9% vs. 6.6%; P = 0.004) and incidence of low cardiac output syndrome (3% vs. 1.2%; p = 0.003) were significantly increased in patients with CECC. Multivariate analysis identified age (p = 0.005; 95% CI 1.01 to 1.08; OR 1.05) among other parameters as an independent risk factor, whereas conventional extracorporeal circulation itself did not present as an independent risk factor for 30-day mortality.
In this matched study sample early outcome was significantly better in patients with MECC compared to CECC, irrespective of age. Prior myocardial infarction estimated GFR < 60 mL and waiving the use of LIMA were independent risk factors for 30-day mortality, which were more present in the CECC group.
Journal of Cardiothoracic Surgery 08/2014; 9(1):143. DOI:10.1186/s13019-014-0143-3 · 1.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Oxygenator thrombosis is a serious complication in extracorporeal membrane oxygenation (ECMO) and may necessitate a system exchange. Coagulation and fibrinolysis parameters, flow dynamics and gas transfer performance are currently used to evaluate the degree of oxygenator thrombosis, but there is no technical approach for direct visualization and quantification of thrombotic deposits within the membrane oxygenator (MO).We used multidetector computed tomography (MDCT) with 3D post-processing to assess the incidence of oxygenator thrombosis, to quantify thrombus extent, and to localize clot distribution. Twenty heparin-coated MOs after successful weaning were analyzed. Mean ECMO support time was 7 ± 4 days, mean activated partial thromboplastin time (aPTT) during ECMO was 59 ± 20 seconds. Thrombotic deposits were detected in all MOs. The mean clot volume was 51.7 ± 22.3 cm³. All thrombotic deposits were located in the venous, i.e. inlet part of the device, without apparent evidence of embolization in patients. There was no correlation between clot volume and ECMO support time or aPTT.Clot formation within the MO is a common finding in ECMO despite adequate systemic anticoagulation. The clinical significance of thrombus formation and its influence on gas exchange capacity and hemostatic complications have to be addressed in further studies.
ASAIO journal (American Society for Artificial Internal Organs: 1992) 08/2014; 60(6). DOI:10.1097/MAT.0000000000000133 · 1.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Zusammenfassung Eine pulmonale Hypertonie kann sowohl kardiale als auch pulmonale Ursachen haben und führt in der Herz-Thorax-Chirurgie zu
einer signifikant erhöhten Letalität. Nachfolgend werden die medikamentösen und chiurgischen Therapieansätze dafür erläutert.
Zeitschrift für Herz- Thorax- und Gefäßchirurgie 06/2014; 16(3). DOI:10.1007/s00398-002-0346-0
[Show abstract][Hide abstract] ABSTRACT: Background
LVAD speed adjustment according to a functioning aortic valve has hypothetic advantages but could lead to submaximal support. The consequences of an open aortic valve policy on exercise capacity and hemodynamics have not yet been investigated systematically.
Ambulatory patients under LVAD support (INCOR®, Berlin Heart, mean support time 465 ± 257 days, average flow 4.0 ± 0.3 L/min) adjusted to maintain a near normal aortic valve function underwent maximal cardiopulmonary exercise testing (CPET) and right heart catheterization (RHC) at rest and during constant work rate exercise (20 Watt).
Although patients (n = 8, mean age 45 ± 13 years) were in NYHA class 2, maximum work-load and peak oxygen uptake on CPET were markedly reduced with 69 ± 13 Watts (35% predicted) and 12 ± 2 mL/min/kg (38% predicted), respectively. All patients showed a typical cardiac limitation pattern and severe ventilatory inefficiency with a slope of ventilation to carbon dioxide output of 42 ± 12. On RHC, patients showed an exercise-induced increase of mean pulmonary artery pressure (from 16 ± 2.4 to 27 ± 2.8 mmHg, p < 0.001), pulmonary artery wedge pressure (from 9 ± 3.3 to 17 ± 5.3 mmHg, p = 0.01), and cardiac output (from 4.7 ± 0.5 to 6.2 ± 1.0 L/min, p = 0.008) with a corresponding slight increase of pulmonary vascular resistance (from 117 ± 35.4 to 125 ± 35.1 dyn*sec*cm−5, p = 0.58) and a decrease of mixed venous oxygen saturation (from 58 ± 6 to 32 ± 9%, p < 0.001).
An open aortic valve strategy leads to impaired exercise capacity and hemodynamics, which is not reflected by NYHA-class. Unknown compensatory mechanisms can be suspected. Further studies comparing higher vs. lower support are needed for optimization of LVAD adjustment strategies.
Journal of Cardiothoracic Surgery 05/2014; 9(1):93. DOI:10.1186/1749-8090-9-93 · 1.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Veno-venous extracorporeal membrane oxygenation (vvECMO) can be a life-saving therapy in patients with severe acute lung failure refractory to conventional therapy. Nevertheless, vvECMO is a procedure associated with high costs and resource utilization. The aim of this study was to assess published models for prediction of mortality following vvECMO and optimize an alternative model.
Established mortality risk scores were validated to assess their usefulness in 304 adult patients undergoing vvECMO for refractory lung failure at the University Medical Center Regensburg from 2008 to 2013. A parsimonious prediction model was developed based on variables available before ECMO initiation using logistic regression modelling. We then assessed whether addition of variables available one day after ECMO implementation enhanced mortality prediction. Models were internally validated and calibrated by bootstrapping (400 runs). Predictive ability, goodness-of-fit and model discrimination were compared across the different models.
In the present study population, existing mortality prediction tools for vvECMO patients showed suboptimal performance. Evaluated before vvECMO initiation, a logistic prediction model comprising age, immunocompromised state, artificial minute ventilation, pre-ECMO serum lactate and haemoglobin concentrations showed best mortality prediction in our patients (area under curve, AUC: 0.75). Additional information about norepinephrine dosage, fraction of inspired oxygen, C-reactive protein and fibrinogen concentrations the first day following ECMO initiation further improved discrimination (AUC: 0.79, P = 0.03) and predictive ability (likelihood ratio test, P < 0.001). When classifying patients as lower (<40%) or higher (>80%) risk based on their predicted mortality, the pre-ECMO and day1-on-ECMO models had negative/positive predictive values of 76%/82% and 82%/81%, respectively.
While pre-ECMO mortality prediction remains a challenge due to large patient heterogeneity, evaluation one day after ECMO initiation may improve the ability to separate lower- and higher-risk patients. Our findings support the clinical perception that chronic health condition, high comorbidity and reduced functional reserves are strongly related to survival during and following ECMO support. Renewed evaluation the first day after ECMO initiation may provide enhanced guidance for further handling of ECMO patients. Despite the usefulness of prediction models, thorough clinical evaluation should always represent the cornerstone in decision for ECMO.