Afksendyios Kalangos

University of Geneva, Genève, GE, Switzerland

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Publications (24)81.62 Total impact

  • Article: Clinical review: management of weaning from cardiopulmonary bypass after cardiac surgery.
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    ABSTRACT: A sizable number of cardiac surgical patients are difficult to wean off cardiopulmonary bypass (CPB) as a result of structural or functional cardiac abnormalities, vasoplegic syndrome, or ventricular dysfunction. In these cases, therapeutic decisions have to be taken quickly for successful separation from CPB. Various crisis management scenarios can be anticipated which emphasizes the importance of basic knowledge in applied cardiovascular physiology, knowledge of pathophysiology of the surgical lesions as well as leadership, and communication between multiple team members in a high-stakes environment. Since the mid-90s, transoesophageal echocardiography has provided an opportunity to assess the completeness of surgery, to identify abnormal circulatory conditions, and to guide specific medical and surgical interventions. However, because of the lack of evidence-based guidelines, there is a large variability regarding the use of cardiovascular drugs and mechanical circulatory support at the time of weaning from the CPB. This review presents key features for risk stratification and risk modulation as well as a standardized physiological approach to achieve successful weaning from CPB.
    Annals of Cardiac Anaesthesia 07/2012; 15(3):206-23.
  • Article: Isolated bilateral profunda femoris artery aneurysm.
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    ABSTRACT: Isolated bilateral profunda femoris artery aneurysm (PFAA) is a very rare entity. Most of the cases are unilateral and occur with synchronous aneurysms elsewhere. Symptoms range from none to limb ischemia or hemorrhage because of rupture. We present a rare case of PFAA. In contrast to the general rule, the patient had a bilateral PFAA which was isolated to the deep femoral artery. The aneurysm was discovered after signs of acute limb ischemia caused by distal embolization. The patient was treated surgically with open aneurysmectomy and ligation of a branch of the deep femoral artery. PFAA are asymptomatic most of the time. Surgical repair is always recommended to prevent such life-threatening complications. Different treatment modalities are offered, including endovascular options. The presence of a PFAA should prompt screening for concomitant aneurysms.
    Annals of Vascular Surgery 08/2010; 24(6):824.e11-3. · 1.03 Impact Factor
  • Article: Isolated cleft mitral valve with posterior and anterior clefts: a rare cause of congenital valve regurgitation.
    Hajo Müller, Afksendyios Kalangos, Amir-Ali Fassa, René Lerch
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    ABSTRACT: We report a case of isolated cleft mitral valve with two clefts in the posterior and one in the anterior leaflet. Our case adds to the few reports of posterior and multiple mitral valve clefts and to our knowledge is the first using real-time transoesophageal three-dimensional echocardiography (3DE) for assessment of isolated cleft mitral valve. (Echocardiography 2010;27:E50-E52).
    Echocardiography 05/2010; 27(5):E50-2. · 1.24 Impact Factor
  • Article: Central venous hypoxemia is a determinant of human atrial ATP-sensitive potassium channel expression: evidence for a novel hypoxia-inducible factor 1alpha-Forkhead box class O signaling pathway.
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    ABSTRACT: ATP-sensitive potassium channels couple cell excitability to energy metabolism, thereby providing life-saving protection of stressed cardiomyocytes. The signaling for ATP-sensitive potassium channel expression is still unknown. We tested involvement of biochemical and biophysical parameters and potential transcription factors Forkhead box (FOX) and hypoxia-inducible factor (HIF-1alpha). Right atrial tissues were obtained during surgery from 28 children with heart disease. Expression of K(+)-inward-rectifier subunits Kir6.1/Kir6.2; sulfonyl urea receptors (SURs) SUR1A/B and SUR2A/B; and FOX class O (FOXO) 1, FOXO3, FOXF2, and HIF-1alpha were related to 31 parameters, including personal data, blood chemistry, and echocardiography. Venous hypoxemia (but not other ischemia indicators, such as venous hypercapnia or low glucose) predicts increased Kir6.1 (P<0.003) and Kir6.2 (P<0.03) protein. Kir6.1 associates with SUR2A/B mRNA (P<0.05) and correlates with FOXOs (P<0.002). FOXOs correlate with HIF-1alpha (P<0.01) and HIF-1alpha with venous hypoxemia (P<0.003). Electrophoretic mobility-shift assays suggest causal links among hypoxia, HIF-1alpha, FOXO1, and Kir6.1. To mimic mild ischemia encountered in some patients, cultured rat atrial myocytes were tested in hypoxia, hypercapnia, or low glucose, with normal conditions serving as the control. Mild hypoxia (24-hour) increases expression of HIF-1alpha, FOXO1, and SUR2A/B/Kir6.1 in culture (P<0.01), whereas hypercapnia and low glucose have no or opposite effects. Gene knockdown of HIF-1alpha or FOXO1 by small-interfering RNAs abolishes hypoxia-induced expression of FOXO1 and SUR2A/B/Kir6.1. These results suggest that low tissue oxygen determines increased expression of the atrial SUR2A/B/Kir6.1 gene via activation of HIF-1alpha-FOXO1. Because increased SUR2A/B/Kir6.1 has known survival benefits, this pathway offers novel therapeutic targets for children with heart disease.
    Hypertension 03/2010; 55(5):1186-92. · 6.21 Impact Factor
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    Article: Preoperative diastolic function predicts the onset of left ventricular dysfunction following aortic valve replacement in high-risk patients with aortic stenosis.
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    ABSTRACT: Left ventricular (LV) dysfunction frequently occurs after cardiac surgery, requiring inotropic treatment and/or mechanical circulatory support. In this study, we aimed to identify clinical, surgical and echocardiographic factors that are associated with LV dysfunction during weaning from cardiopulmonary bypass (CPB) in high-risk patients undergoing valve replacement for aortic stenosis. Perioperative data were prospectively collected in 108 surgical candidates with an expected operative mortality >or=9%. All anesthetic and surgical techniques were standardized. Reduced LV systolic function was defined by an ejection fraction <40%. Diastolic function of the LV was assessed using standard Doppler-derived parameters, tissue Doppler Imaging (TDI) and transmitral flow propagation velocity (Vp). Doppler-derived pulmonary flow indices and TDI could not be obtained in 14 patients. In the remaining 94 patients, poor systolic LV was documented in 14% (n = 12) and diastolic dysfunction in 84% of patients (n = 89), all of whom had Vp <50 cm/s. During weaning from CPB, 38 patients (40%) required inotropic and/or mechanical circulatory support. By multivariate regression analysis, we identified three independent predictors of LV systolic dysfunction: age (Odds ratio [OR] = 1.11; 95% confidence interval (CI), 1.01 to 1.22), aortic clamping time (OR = 1.04; 95% CI, 1.00 to 1.08) and Vp (OR = 0.65; 95% CI, 0.52 to 0.81). Among echocardiographic measurements, Vp was found to be superior in terms of prognostic value and reliability. The best cut-off value for Vp to predict LV dysfunction was 40 cm/s (sensitivity of 72% and specificity 94%). Patients who experienced LV dysfunction presented higher in-hospital mortality (18.4% vs. 3.6% in patients without LV dysfunction, P = 0.044) and an increased incidence of serious cardiac events (81.6 vs. 28.6%, P < 0.001). This study provides the first evidence that, besides advanced age and prolonged myocardial ischemic time, LV diastolic dysfunction characterized by Vp <or= 40 cm/sec identifies patients who will require cardiovascular support following valve replacement for aortic stenosis.
    Critical care (London, England) 01/2010; 14(3):R101. · 4.61 Impact Factor
  • Chapter: Mitral Valve Anomalies and Related Disorders
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    ABSTRACT: This chapter will discuss mitral disorders with the exception of mitral stenosis to which a specific chapter has been dedicated in this book. It will also provide information about some associated entities such as Marfan syndrome (MFS) and rheumatic disease.
    12/2009: pages 273-299;
  • Article: Value of brain natriuretic peptide in the perioperative follow-up of children with valvular disease.
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    ABSTRACT: To characterize N-terminal pro-brain natriuretic peptide (N-proBNP) and troponin I (TnI) profile following mitral and/or aortic valve surgery and to evaluate correlations with echocardiography measures and outcome criteria. Prospective cross-controlled study in a university children's hospital. Twenty children with acquired valvular disease requiring valvular surgery. We prospectively studied clinical, biochemical, and echocardiographic characteristics at baseline and 6, 12, 24 h and 3-4 weeks postoperatively. TnI peaked 6 h after surgery and remained elevated during the first 24 h. N-proBNP was significantly lower 3-4 weeks after surgery than during the perioperative period. Overall, N-proBNP was correlated with the Pediatric Heart Failure Index, left ventricle shortening fraction, left atrium to aorta ratio, left ventricle mass index, end-systolic wall stress, and with outcome measures such as inotropic score, duration of inotropic support, and ICU length of stay. Preoperative N-proBNP was significantly more elevated in patients with complicated outcome than in patients with uneventful postoperative course. In pediatric valvular patients, perioperative N-proBNP is a promising risk stratification predicting factor. It is correlated with evolutive echocardiographic measures, need for inotropic support, and ICU length of stay.
    Intensive Care Medicine 07/2008; 34(6):1109-13. · 5.40 Impact Factor
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    Article: Fate of undifferentiated mouse embryonic stem cells within the rat heart: role of myocardial infarction and immune suppression.
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    ABSTRACT: Abstract It has recently been suggested that the infarcted rat heart microenvironment could direct pluripotent mouse embryonic stem cells to differentiate into cardiomyocytes through an in situ paracrine action. To investigate whether the heart can function as a cardiogenic niche and confer an immune privilege to embryonic stem cells, we assessed the cardiac differentiation potential of undifferentiated mouse embryonic stem cells (mESC) injected into normal, acutely or chronically infarcted rat hearts. We found that mESC survival depended on immunosuppression both in normal and infarcted hearts. However, upon Cyclosporin A treatment, both normal and infarcted rat hearts failed to induce selective cardiac differentiation of implanted mESC. Instead, teratomas developed in normal and infarcted rat hearts 1 week and 4 weeks (50% and 100%, respectively) after cell injection. Tight control of ESC commitment into a specific cardiac lineage is mandatory to avoid the risk of uncontrolled growth and tumourigenesis following transplantation of highly plastic cells into a diseased myocardium.
    Journal of Cellular and Molecular Medicine 04/2008; 13(1):188-201. · 4.13 Impact Factor
  • Article: Aortic arch repair and cold-reactive agglutinins: what to do?
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    ABSTRACT: We describe a modified perfusion technique for aortic arch repair under mild hypothermia and continuous cerebral and systemic perfusion.
    The Annals of thoracic surgery 11/2007; 84(4):1403-4. · 3.74 Impact Factor
  • Article: Long intraaortic balloon treatment time leads to more vascular complications.
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    ABSTRACT: Intraaortic balloon counterpulsation is an established and efficient therapy. Limb ischemia is the most common complication. The impact of treatment duration on balloon-related complications was analyzed retrospectively in 135 patients who underwent balloon counterpulsation between 1998 and 2004. Thirty high-risk coronary patients required preoperative intraaortic balloon therapy, 41 were in preoperative cardiogenic shock, and 64 needed support for difficulties in weaning from cardiopulmonary bypass. No balloon-related mortality occurred. The overall balloon-related complication rate was 20/135 (14.8%); 18 had limb ischemia, of whom 6 (4.4%) required vascular interventions. Intraaortic balloon treatment time was significantly longer in patients who developed limb ischemia (99.8 +/- 54.1 h) compared to those who did not (34.4 +/- 30.4 h). Preoperative therapy had short treatment times and few complications. Intraaortic balloon pumping provides effective circulatory support with a low complication rate. A clear relationship was established between duration of treatment and balloon-related complications. Independent risk factors for balloon-related complications were long treatment time, acute myocardial infarction, age over 65 years, and ejection fraction less than 0.30.
    Asian cardiovascular & thoracic annals 11/2007; 15(5):408-12.
  • Article: Mechanical support availability in pediatric cardiac surgery: program size should not matter.
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    ABSTRACT: Intractable heart failure may require Extracorporeal Life Support (ECLS) techniques for rescue therapy. Nevertheless, in many small to middle-sized centers in Europe, this valuable resource is not available. In our University pediatric intensive care unit 0.9% of 1360 open-heart surgical patients required mechanical assistance over the latest 9 years with a survival rate of 69.2% and low residual morbidity. This favorable overall outcome suggests that regardless of the program size, it is possible to ensure the availability of efficient mechanical assistance that appears to be fundamental in a center performing surgery for complex congenital or acquired cardiac diseases.
    International journal of cardiology 09/2007; 129(2):282-4. · 7.08 Impact Factor
  • Article: Traumatic isthmic aortic rupture associated with renal fracture in a child.
    The Journal of trauma 07/2007; 62(6):1501-3. · 2.48 Impact Factor
  • Article: Tissue plasminogen activator for a left atrial thrombus after Senning repair.
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    ABSTRACT: To avoid the surgical removal of an obstructive thrombus in a Senning baffle by the administration of recombinant tissue-type plasminogen activator. A pediatric intensive care unit in a children's university hospital. A 3-yr-old male was diagnosed with a large left atrial thrombus 2 wks after Senning repair for D-transposition of the great arteries. The child presented with massive chylous pleural, pericardial effusions, and cardiac tamponade, secondary to partial obstruction of the pulmonary venous channel. Thrombolysis with recombinant tissue-type plasminogen activator was instituted. We observed a resolution of the thrombus in <48 hrs. Minor local bleeding was the only noted side effect. No signs of systemic thromboembolization were detected. Early thrombolysis with recombinant tissue-type plasminogen activator could be considered a possible alternative to surgical thrombectomy in selected postoperative pediatric cases, although there may be a potential risk of serious bleeding.
    Pediatric Critical Care Medicine 05/2007; 8(3):279-81. · 3.13 Impact Factor
  • Article: Left ventricular epicardial VVI pacing for a congenital complete heart block with severe myocardial dysfunction: shall epicardial pacing wires be positioned left?
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    ABSTRACT: We present the case of a patient with a congenital complete heart block (CHB) who developed a severe dilated hypokinetic cardiomyopathy whilst paced with a right-sided epicardial wire inserted by an anterior approach. She dramatically and rapidly improved both clinically and echocardiographically, once a single pacing wire was inserted on the left ventricular (LV) wall towards the apex by left thoracotomy. Based upon recent literature, attention is drawn to the fact that left-inserted epicardial pacing wires should probably be considered for pediatric patients in whom atrio-ventricular or inter-ventricular pacing might not be possible to achieve, or else as a consistent approach for small patients requiring VVI epicardial pacing.
    International journal of cardiology 04/2007; 116(1):e7-9. · 7.08 Impact Factor
  • Article: The Lecompte maneuver as an alternative to reduction pulmonary arterioplasty for relief of airway compression in absent pulmonary valve syndrome.
    The Annals of thoracic surgery 03/2007; 83(2):727; author reply 727-8. · 3.74 Impact Factor
  • Article: Comparison of classifications for heart failure in children undergoing valvular surgery.
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    ABSTRACT: To characterize correlations between clinical classifications of heart failure and diagnostic workup. Pre- and postoperative characteristics of 20 children with heart failure secondary to valvular rheumatic disease were studied. Both scoring systems correlated with N-terminal pro-brain natriuretic peptide (N-proBNP) but not with troponin I (TnI). The PHFI correlated with N-proBNP, end-systolic wall stress, left ventricular mass index and left atrium to aorta diameter ratio. No correlation could be established between modified Ross score, or the New York Heart Association (NYHA) grade and echocardiographic measurements. Cardiothoracic and Sokolow indexes were correlated with the PHFI as well as to the NYHA classification. In this study, PHFI seems better correlated with radiologic, electrocardiographic, echocardiographic, and biologic assessment of heart failure in children. Clinical severity was correlated with N-proBNP but not with TnI.
    Journal of Pediatrics 09/2006; 149(2):210-5. · 4.11 Impact Factor
  • Article: Late cardiac tamponade after percutaneous closure of a patent foramen ovale.
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    ABSTRACT: We report the case of a 35-year-old man who had a transient ischemic cerebral attack and then underwent a percutaneous closure of the patent foramen ovale (PFO) with a Cardiastar device. One year later, the patient developed a cardiac tamponade due to an important hemorrhagic pericardial effusion. Transoesophageal echocardiography showed that one of the struts had impinged on the aortic root in the region adjacent to the transverse pericardial sinus. Therefore, we speculated that the strut had passed through the aortic wall by slow erosion, leading to the pericardial effusion. Cardiac CT and subsequent surgery confirmed the perforation of the left atrial roof and the aortic root by two struts of the device. This is the first reported case of late cardiac tamponade and underscores the importance of long-term follow-up after PFO closure device implantation.
    European Heart Journal – Cardiovascular Imaging 01/2006; 6(6):465-9. · 2.32 Impact Factor
  • Article: Asymptomatic traumatic pericardial rupture with partial right atrial herniation: case report.
    The Journal of trauma 06/2005; 58(5):1068-72. · 2.48 Impact Factor
  • Article: Extratracheal biodegradable splint to treat life-threatening tracheomalacia.
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    ABSTRACT: A 9-month-old girl presented with life-threatening acute respiratory failure 1 week after the surgical correction of a double aortic arch, which was due to a severe bulging of the pars membranacea into the lumen of the trachea that produced a complete obstruction of the lower trachea. Under cardiopulmonary bypass, a Y-shaped posterior biodegradable splint was placed behind the trachea and sutured to the posterior trachea, and a simultaneous right aortic arch aortopexy was performed. Thereafter, the child recovered normal respiratory function. Follow-up bronchoscopy showed a posterior dip at the splint level and an asymptomatic persistent posterior compression of the right main bronchus.
    The Annals of thoracic surgery 11/2004; 78(4):1446-8. · 3.74 Impact Factor
  • Article: Early clinical results of the telemetric adjustable pulmonary artery banding FloWatch-PAB.
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    ABSTRACT: Adjustment of pulmonary artery banding (PAB) may be a challenging procedure in complex congenital heart defects. Whatever the technique used, subsequent re-operations are frequently needed to control the pulmonary blood flow or pressures. To report the efficacy of a new telemetric adjustable PAB (FloWatch-PAB) operated with the help of an external control unit that transmits to the implant energy and commands to further narrow or release the pulmonary artery using radiofrequency waves. In a multicenter, prospective, nonrandomized, single-arm clinical investigation, 13 children (median age, 4.5 months; range, 6 days to 11 years; median weight, 4.2 kg; range, 3.1 to 27 kg) underwent implantation of the FloWatch-PAB through median sternotomy in 8 and left thoracotomy in 5. The diagnosis was multiple ventricular septal (VSD) defects with complex anatomy in 3, single ventricle without pulmonary stenosis in 2, VSD with elevated pulmonary vascular resistance (PVR) in 2, atrio-ventricular canal (AVC) with elevated pulmonary vascular resistance in 1, AVC with diminutive right ventricle in 1, complex transposition of the great arteries in 3, and pulmonary atresia with complex pulmonary arteries anatomy in 1. All patients had normosystemic systolic pulmonary artery pressure. Additional procedures were performed in 7: atrial septectomy in 2, double aortic arch division in 1, patent ductus arteriosus ligation in 2, and coarctation repair in 2. There were no early or late deaths or device-related complications in a mean follow-up of 24 weeks (range, 18 to 42 weeks). A mean of 5.8 telemetric regulations per patient using the FloWatch-PAB were required to adjust the tightening of the PAB to the clinical needs (narrowing 74%, releasing 26%). At last follow-up, systolic pulmonary artery pressure was within normal range in all patients but 1. Systemic oxygen saturation demonstrated optimal regulation of the pulmonary blood flow in all according to each specific defect. Four patients were successfully corrected (VSD closure, AVSD repair, and 2 arterial switches with VSD closure). The device was easily removed and the pulmonary artery re-expanded spontaneously. This new device is safe and allows optimal adjustment of PAB in complex heart defects. In children requiring PAB, the use of this technology can obviate the need for early re-operations and appears to be a valuable option in the panel of surgical alternatives for selected infants.
    Circulation 10/2004; 110(11 Suppl 1):II158-63. · 14.74 Impact Factor