Stéphane Aubert

Pierre and Marie Curie University - Paris 6, Lutetia Parisorum, Île-de-France, France

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Publications (52)94.62 Total impact

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    ABSTRACT: Valve repair is currently performed to treat mitral regurgitation, but aortic valve repair remains a surgical challenge. In contrast, aortic valve replacement leads to complications and constraints on the patients' quality of life and valve durability. The mechanisms that produce malcoaptation of the aortic leaflets, with resultant insufficiency, are mainly due to prolapse or retraction of the leaflets. Thus, a new strategy has been proposed to correct valvular insufficiency, using magnetic force. Low-profile permanent magnets were implanted in seven sheep, under cardiopulmonary bypass (CPB), through a transverse aortotomy, and maintained in place for three months. No aortic insufficiency was created in these first experiments. Two-dimensional color Doppler echocardiography was used to assess the function and safeguarding of the aortic valve. Blood samples were withdrawn to assess hemolysis, and histopathologic examinations performed at necropsy. Direct implantation of the three permanent magnets was possible in all seven animals, but the surgical procedure resulted in major complications in three cases. Only five animals could be weaned from CPB, and only four survived the procedure at three months. One magnet was also shown to have migrated postoperatively. Echocardiography confirmed the stability of the aortic leaflet contours. The biocompatibility of the implanted magnets (i.e., absence of hemolytic reaction) was found to be satisfactory, without a need for postoperative anticoagulation. The use of magnetic force to correct valvular insufficiency has not previously been reported, and is an interesting field of investigation. Whilst these experiments are at an early stage of development, future changes in magnet design and surgical approach are indicated.
    The Journal of heart valve disease 01/2011; 20(1):70-4. · 1.07 Impact Factor
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    Stéphane Aubert, Erwan Flecher
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    ABSTRACT: Quadrangular resection is the gold standard in the treatment of posterior leaflet prolapse. Anterior leaflet prolapse has been considered a more challenging problem; several techniques are available to treat it, all with the same goal - mitral valve competency. Nowadays, good long-term results are reported, similar to those for posterior leaflet prolapse. Certain improvements may explain these results, especially improvements in transesophageal echocardiography (including three-dimensional echocardiography), which allow the detection of atypical mitral regurgitation and its mechanism.
    Archives of cardiovascular diseases 03/2010; 103(3):192-5. · 0.66 Impact Factor
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    ABSTRACT: Morbidity from calcific aortic valve disease (CAVD) is increasing. Recent studies suggest early reversible changes involving inflammation and neoangiogenesis. We hypothesized that microcalcifications, chemokines, and growth factors are present in unaffected regions of calcific aortic valves. We studied aortic valves from 4 patients with CAVD and from 1 control, using immunohistochemistry, scanning electron microscopy, and infrared spectrography. We revealed clusters of capillary neovessels in calcified (ECC), to a lesser extent in noncalcified (ECN) areas. Endothelial cells proved constant expression of SDF-1 in ECC, ECN, and endothelial cells from valvular surface (ECS). Its receptor CXCR4 was expressed in ECC. IL-6 expression correlated with CXCR4 staining and presence of lymphocytes. VEGF was expressed by ECS, its receptor by ECC and ECN. Crystalline ultrastructures were found on the surface of histologically noncalcified areas (HNCAs), spectrography revealed calcium hydroxylapatite. Our results demonstrate that crystalline ultrastructures are present in HNCAs, undergoing neoangiogenesis in an inflammatory context. These alterations could be an early witness of disease and an opening to therapy.
    Cardiology research and practice. 01/2010; 2010:685926.
  • Journal of Heart and Lung Transplantation - J HEART LUNG TRANSPLANT. 01/2010; 29(2).
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    ABSTRACT: Early graft failure (EGF) is a major risk for death after heart transplantation. We studied the impact of an extra-corporeal membrane oxygenation (ECMO) temporary support on the operative mortality and the mean-term survival after EGF. Between January 2000 and December 2006, 394 patients underwent orthotopic heart transplantation at our institution. EGF was observed in 90 (23%) patients. Fifty-four patients (14%) were treated with ECMO support, eight (2%) with other assisting devices, and 28 (7%) received maximal inotropic drug support only. The overall mortality was 21% (83 patients). EGF was a major risk for death: 13% (35 patients) without EGF versus 58% (49 patients) with EGF, p<0001. Among patients supported with ECMO, 36 (67%) were weaned from the assisting device and 27 (50%) were discharged from the hospital. Overall survival was 73% at 1 year and 66% at 5 years. Absence of EGF improved long-term survival: 78% at 1 year and 70% at 5 years without EGF versus 37% at 1 year and 35% at 5 years with EGF. Patients treated with ECMO have the same 1-year conditional survival as patients not having suffered EGF: 94% at 3 years. ECMO support is a reliable therapeutic option in severe EGF after cardiac transplantation; furthermore, patients treated with ECMO have the same 1-year conditional survival as patients not having suffered EGF.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 08/2009; 37(2):343-9. · 2.40 Impact Factor
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    ABSTRACT: Aortic valve replacement (AVR) in patients who have undergone previous coronary artery bypass grafting (CABG) is a challenging redo surgery. We undertook this study to evaluate the early and late outcomes of patients operated upon using a simplified surgical approach. Between January 2001 and December 2005, 2238 patients underwent AVR in our institution. We reviewed retrospectively the 57 patients who had AVR following previous CABG. All patients underwent cardiopulmonary bypass with a mild-to-moderate systemic hypothermia (mean temperature: 29.7 +/- 2.5 degrees C). Patent internal thoracic artery (IMA) grafts were never dissected, controlled or clamped. A mechanical or biological prosthesis was implanted considering the patient's age. The mean cardiopulmonary bypass (CPB) time was 93 +/- 29 min (median: 80 min, range: 43-244 min) and the mean aortic cross-clamp (AoX) time was 63 +/- 18 min (median: 59 min, range: 31-125 min). The early mortality was 10.5% and the late mortality was 9.8% (mean follow-up time: 38 months). The survival was 81% at 5 years and the freedom from major cardiac events was 77%. In conclusion, from our experience, the operating quickness and a simplified approach ('open IMA technique', anterograde cardioplegia, mild-to-moderate hypothermia and minimal dissection of the mediastinal structures) represent two fundamental choices to perform this type of surgery easily, safely and with optimal results.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 07/2009; 36(2):404-6. · 2.40 Impact Factor
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    ABSTRACT: The role of oligo-elements such as Zn in the genesis of pathological calcifications is widely debated in the literature. An essential element of discussion is given by their localisation either at the surface or within the Ca apatite crystalline network. To determine the localisation, X-ray absorption experiments have been performed at SOLEIL. The Exafs results suggest that Zn atoms, present in the Zn(2+) form, are bound to about 4 O atoms at a distance of 2.00 A, while the interatomic distance R(CaO) ranges between 2.35 A and 2.71 A. Taking into account the content of Zn (around 1000 ppm) and the difference in ionic radius between Zn(2+) (0.074 nm) and Ca(2+) (0.099 nm), a significant longer interatomic distance would be expected in the case of Zn replacing Ca within the apatite crystalline network. We thus conclude that Zn atoms are localised at the surface and not in the apatite nanocrystal structure. Such structural result has essential biological implications for at least two reasons. Some oligoelements have a marked effect on the transformation of chemical phases, and may modify the morphology of crystals. These are both major issues because, in the case of kidney stones, the medical treatment depends strongly on the precise chemical phase and on the morphology of the biological entities at both macroscopic and mesoscopic scales.
    Biochimie 07/2009; 91(10):1294-300. · 3.14 Impact Factor
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    Stéphane Aubert, Christophe Acar
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    ABSTRACT: Naturally occurring clefts in the posterior leaflet of the mitral valve and/or the mitral commissures themselves may become the foci of residual mitral regurgitation when distorted by an adjacent rigid suture line. Herein are reported the details of three cases in which cleft/commissure closure resolved such leaks. The anatomical substrate which predisposed to this problem is also discussed.
    The Journal of heart valve disease 06/2009; 18(3):290-1. · 1.07 Impact Factor
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    ABSTRACT: Biventricular assist device support with a paracorporeal pulsatile device is known to be an efficient bridge to recovery for patients with fulminant myocarditis-related cardiogenic shock. Whether these patients can be as efficiently supported with femorofemoral extracorporeal membrane oxygenation remains unclear. From 2001 to 2006, 11 patients were referred to our cardiac surgery department for fulminant myocarditis-related cardiogenic shock. The first 5 patients (mean age, 32 +/- 2 years) were supported with a biventricular assist device (Thoratec, Pleasanton, Calif; group I), whereas the remaining patients (40 +/- 4 years) were supported with femorofemoral extracorporeal membrane oxygenation (group II). Preimplantation probability of death was calculated by using the APACHE II score, which was 11 +/- 9 in group I versus 24 +/- 18 in group II. One patient in each group died while receiving support. In group I the death occurred after 18 days of support in a patient who had 45 minutes of external resuscitation before biventricular assist device implantation. In group II a patient who remained unstable during extracorporeal membrane oxygenation was switched to a biventricular assist device 13 days later and eventually died of tamponade after 45 days. All other patients were weaned from the device after a mean duration of support of 21 +/- 5 days in group I versus 13 +/- 4 days in group II. At hospital discharge, the mean ejection fraction was 45% +/- 5% in both groups, and at 6 months' follow-up, it was 65% and 75%, respectively, in groups I and II. In our experience extracorporeal membrane oxygenation is as efficient as use of a biventricular assist device as a bridge to recovery for patients with fulminant myocarditis-related cardiogenic shock and facilitates renal and hepatic recovery on support.
    The Journal of thoracic and cardiovascular surgery 02/2009; 137(1):194-7. · 3.41 Impact Factor
  • Journal of Heart and Lung Transplantation - J HEART LUNG TRANSPLANT. 01/2009; 28(2).
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    ABSTRACT: Using echocardiography, perioperative assessment of systolic function by fractional area change (FAC) is questionable in patients suffering from mitral regurgitation (MR). Tei index, an index expressing global cardiac function, has been reported to be unchanged after mitral valve surgery. We tested the hypothesis where the Tei index could be useful in assessing the perioperative cardiac function in patients undergoing mitral valve repair (MVR). Twenty-five patients were enrolled. Transoesophageal echocardiography was performed perioperatively before and after the correction of MR. We compared the impact of the MVR on the left ventricular FAC and the Tei index. FAC was calculated from the transgastric short-axis view and Tei index was determined from the four chambers and deep transgastric views. Two patients were excluded because of poor acoustic windows. FAC significantly decreased after MVR from 53 (9)% to 42 (10)% (P<0.001), while Tei index was unaffected [0.46 (0.16) vs 0.47 (0.17), NS]. A significant relationship was found between the preoperative Tei index and the postoperative FAC (R=-0.64, P<0.001). Moreover, a significant and clinically relevant relationship was determined between the predicted (using preoperative Tei index) and the measured postoperative FAC (R=0.64, P<0.001). FAC but not the Tei index is influenced by MVR. The preoperative determination of the Tei index allows predicting postoperative FAC and offers the opportunity to identify patients in whom a severe unsuspected systolic dysfunction could render difficult the weaning from cardiopulmonary bypass.
    BJA British Journal of Anaesthesia 10/2008; 101(4):479-85. · 4.24 Impact Factor
  • European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 10/2008; 34(5):1109. · 2.40 Impact Factor
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    ABSTRACT: Iatrogenic injury to the circumflex coronary artery following mitral annuloplasty is a potentially fatal complication. It can be clinically silent or else be responsible for a cardiogenic shock. The diagnosis should be suspected on EKG changes with segmental dysfunction of the lateral wall on the intraoperative echography. The author reports one case whose recognition relied on emergency angiography; the patient was successfully treated by angioplasty and stenting. The management of this complication remains controversial and the various treatment modalities are discussed.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 09/2008; 34(4):922-4. · 2.40 Impact Factor
  • Nicola Vistarini, Stéphane Aubert, Iradj Gandjbakhch
    The Annals of thoracic surgery 08/2008; 86(1):314. · 3.45 Impact Factor
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    ABSTRACT: The number of heart transplants in France has begun to increase again in the past few years, albeit slowly. Indications for transplants must be discussed on a case-by-case basis and no contraindication should be considered absolute. Heart transplant results have not been modified by the expansion of the selection criteria for donors. The "super-urgent" list makes it possible to provide transplants for the patients at highest risk of imminent death, with encouraging results. The repercussions of "super-urgent" transplants must be analyzed regularly. Quality of life must be taken into account in the analysis of heart transplant results, just like survival. New circulatory assist devices can be offered to some patients as an alternative to transplantation.
    La Presse Médicale 07/2008; 37(6 Pt 2):1085-92. · 0.87 Impact Factor
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    ABSTRACT: A 50-year-old female operated of Bentall five years before was referred to our hospital for an aneurysm of both right subclavian artery and brachiocephalic trunk associated with a false anastomotic aneurysm on the insertion of the left coronary artery. The procedure was performed under moderate hypothermic circulatory arrest; the false aneurysm was repaired, the brachiocephalic trunk and the subclavian aneurysm were resected, an aorto-carotid and axillary bypass were finally performed. The postoperative course was uneventful. She was discharged to home on postoperative day 7. At six-month follow-up, she was still asymptomatic.
    Journal of Cardiac Surgery 04/2008; 23(5):513-4. · 1.35 Impact Factor
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    ABSTRACT: Optimal treatment of type B dissections is open to debate. The use of endoprostheses is an option that requires evaluation. To report our experience with endoprostheses in type B aortic dissections. We report our short- and medium-term results with covered prostheses for the treatment of acute (n=7) and chronic (n=28) type B aortic dissections. The criteria used to indicate treatment were the same as those usually used for surgery: acute complications or dilated aneurysm. Cover of the main intimal tear was obtained in all cases with an improvement in symptoms in patients with acute dissections. Early mortality was 14.3% (five patients), linked in three cases to the occurrence of a retrograde dissection of the ascending aorta. No neurological complications were observed. Four patients required an additional endovascular and/or surgical procedure. On early control scans, complete thrombosis of the false lumen at the thoracic level was observed in 40% of cases, partial thrombosis in 42.8% and an absence of thrombosis in 11.4%. After a mean follow-up of 20.8 months, one patient died of a pneumopathy. No secondary aneurysm expansion was noted at the thoracic stage whereas three patients presented with dilation of the abdominal aorta. The results of treatment of type B dissections with covered endoprostheses are encouraging. However, the morbimortality associated with treatment and the uncertainty of long-term results do not allow the use of this therapeutic option outside the criteria usually recognized to indicate surgery.
    Archives of Cardiovascular Diseases 03/2008; 101(2):94-9. · 1.66 Impact Factor
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    ABSTRACT: We present a rare case of bullet embolism from the left brachiocephalic vein to the right ventricle, following a chest gunshot wound, in a 56-year-old soldier. The bullet was accidentally discovered on a systematic chest X-ray. The bullet was very close to the tricuspid subvalvular apparatus and was about to come out from the ventricle. We removed it under cardiopulmonary bypass.
    Journal of Cardiac Surgery 01/2008; 23(2):176-7. · 1.35 Impact Factor
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    Archives of Cardiovascular Diseases 01/2008; 101(11-12):793-4. · 1.66 Impact Factor
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    ABSTRACT: The study aim was to assess the characteristics of bacterial endocarditis complicating mitral annulus calcification, and to evaluate the surgical results. Twenty-four patients (mean age 64 years) underwent surgery for mitral insufficiency secondary to mitral endocarditis with annulus calcification (acute, n = 18; healed, n = 6). Surgery was performed as an emergency in seven cases for septic (n = 3) or cardiogenic (n = 4) shock. An aortic prosthesis had previously been placed in three cases. Comorbidities noted included chronic renal insufficiency/dialysis (n = 8), cancer (n = 6), coronary disease (n = 6), and obstructive cardiomyopathy (n = 1). Nine patients suffered an embolic complication, such as stroke (n = 7, of which three had coma), splenic (n = 3), or lower limb (n = 1). The microorganism present was identified as Staphylococcus aureus (n = 9), Streptococcus/ Enterococcus sp. (n = 12), or others (n = 3). The left atrial diameter was 48 mm, the ejection fraction 63%, and the septal thickness 13 mm. The mean severity score of annulus calcifications (range: 1 to 5) was 1.9. The anatomical lesions included: vegetations (n = 16, of which eight were > 10 mm), leaflet perforation (n = 9), chordae rupture (n = 9), aortic abscess (n = 2) and mitral annular abscess (n = 9), and one fistulation into the pericardium. The valve was repaired in 15 cases, and replaced in nine (seven bioprostheses, two mechanical). Associated procedures included aortic valve replacement (n = 7) and coronary artery bypass (n = 3). The in-hospital mortality was 29% (n = 7); all patients who died were operated on during the acute phase. All patients who presented with septic shock or coma died. After a mean follow up of 46 months, six patients had died (overall survival was 46% at 33 months), and 11 were in NYHA class I/II. One recurrence of endocarditis was treated medically. Bacterial endocarditis complicating mitral annulus calcification has a poor prognosis due to the frequent comorbidity and severity of the infectious complications. Patients in septic shock or coma do not appear to be suitable candidates for surgery. Valve repair was possible in two-thirds of the present patients; otherwise, a bioprosthetic replacement was the option of choice.
    The Journal of heart valve disease 11/2007; 16(6):611-6. · 1.07 Impact Factor

Publication Stats

276 Citations
94.62 Total Impact Points

Institutions

  • 2007–2009
    • Pierre and Marie Curie University - Paris 6
      Lutetia Parisorum, Île-de-France, France
    • Instituto do Coração
      San Paulo, São Paulo, Brazil
    • Hôpital La Pitié Salpêtrière (Groupe Hospitalier "La Pitié Salpêtrière - Charles Foix")
      Lutetia Parisorum, Île-de-France, France
  • 2008
    • Texas Heart Institute
      Houston, Texas, United States
  • 2005–2006
    • Royal Brompton and Harefield NHS Foundation Trust
      Harefield, England, United Kingdom
  • 2004–2005
    • Claude Bernard University Lyon 1
      Villeurbanne, Rhône-Alpes, France