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Alain Carpentier

Publications and source records attributed to Alain Carpentier.

36 records · Page 2Linked to original sources
PubMed2003

Exhaled carbon monoxide and inducible heme oxygenase expression in a rat model of postperfusion acute lung injury.

OBJECTIVE: Expression of inducible heme oxygenase has been shown to be increased in various visceral inflammatory disorders, which may confer a protective role. The purpose of our study was to determine whether the expression of inducible heme oxygenase was up-regulated within lungs in a rat model of extracorporeal circulation. METHODS: Wistar rats underwent either a partial femoro-femoral extracorporeal circulation in normothermia for 3 hours (n = 5) or a sham procedure (n = 5). Exhaled carbon monoxide concentration was monitored with an infrared analyzer. After the rats were killed, lungs were harvested for determination of heme oxygenase activity and inducible heme oxygenase expression (by Western blot and immunohistochemistry). Lung injury was also assessed by arterial blood gas analysis and microscopic study. RESULTS: Extracorporeal circulation was responsible for a lung injury characterized by decreased arterial blood oxygen saturation and typical morphologic findings (marked alveolar neutrophil infiltration; interstitial edema). Exhaled carbon monoxide concentration remained stable throughout the experiment in all sham rats, whereas it increased after extracorporeal circulation (from 0.16 +/- 0.05 ppm at baseline to 0.7 +/- 0.2 ppm at end of experiment; P =.0001). Pulmonary heme oxygenase activity and inducible heme oxygenase content (assessed by Western blot) were increased within lungs of rats that underwent extracorporeal circulation. Immunohistochemistry revealed that the expression of inducible heme oxygenase was mainly localized to inflammatory cells. CONCLUSIONS: Post-extracorporeal circulation acute lung injury in rats was associated with an increased expression of inducible heme oxygenase, the functional significance of which remains to be determined.

Acute Disease↗
PubMed2003

Leaflet concavity: a rapid visual clue to the presence and mechanism of functional mitral regurgitation.

Repairing mitral regurgitation (MR) requires an understanding of its mechanism. Evaluating restricted leaflet closure in functional MR is challenging. Tenting area between leaflets and annulus in long-axis (LAX) views correlates with MR, but is positive even in control subjects; in the 4-chamber view, the incomplete mitral leaflet closure (IMLC) tenting pattern may be subtle and variable. We tested the hypothesis that leaflet concavity toward the left atrium in the LAX view, a rapid visual clue indicating abnormal tethering predominantly by intermediate chords, is a strong indicator of functional MR. We reviewed 90 patients: 40 with inferior myocardial infarction and ejection fraction > or = 50%; 40 with global left ventricular dysfunction and ejection fraction < 50%; and 10 control subjects. We assessed leaflet shape (concave or convex toward the left atrium) and maximum systolic proximal MR jet width in the LAX views. To quantify shape, we measured the leaflet concavity area between the anterior leaflet and a line connecting its ends. Conventional IMLC area was also assessed. Patients with leaflet concavity had significantly greater MR than those without this finding (jet width of 4.6 +/- 0.7 vs 0.5 +/- 0.1 mm, P <.0001), indicating mild-moderate versus trace MR, with differences comparable in those with inferior myocardial infarction and left ventricular dysfunction. Leaflet concavity area most strongly predicted MR by multivariate regression (R(2) = 0.7). Conventional IMLC area did not uniquely distinguish patients with or without MR and correlated more weakly with MR (R(2) = 0.30 vs 0.73). Mitral leaflet concavity in the LAX view provides rapid and reliable recognition of functional MR, with greater reliability than IMLC area. This shape, consistent with tethering by intermediate chords, may have implications for potential intervention.

Aged↗
PubMed2003

Exhaled nitric oxide and acute lung injury in a rat model of extracorporeal circulation.

Exhaled nitric oxide (NO) concentration, a marker of pulmonary inflammation, has been shown to be elevated in various models of acute lung injury (ALI). This study was undertaken to evaluate the pulmonary NO production in a rat model of postextracorporeal circulation (ECC) ALI. Wistar rats underwent either a partial femorofemoral ECC in normothermia for 3 h (n = 10) or a sham procedure (n = 10). The extracorporeal circuit consisted of a roller pump and a membrane oxygenator. Exhaled NO concentration was monitored with a chemiluminescence analyzer. After sacrifice, lungs were harvested for microscopic studies and to analyze the inducible nitric oxide synthase (iNOS) activity and expression (Western blot). ECC was responsible for an ALI characterized by a decreased arterial blood oxygen saturation (88.9% [51.7-94.2] vs. 93.7% [91.4-98.6] P = 0.005) and pulmonary histological changes (marked alveolar neutrophil infiltration; interstitial edema; intraalveolar hemorrhage). The lung injury score was significantly higher in the ECC group (n = 5; 3.0 [2-4]) in comparison to the sham group (n = 5; 1.0 [0-2]). Exhaled NO concentration remained stable throughout the experiment in all sham rats whereas it significantly increased in the ECC group from baseline (2 ppb [1-5]) until the end of experiment (33.5 ppb [1-47]). Lung iNOS activity and expression were also significantly increased in the ECC group. An increase in exhaled NO, however, did not correlate with the decrease in arterial oxygen pressure. ECC was responsible for an ALI in rats and for an elevated pulmonary NO production. Determination of the relationship between exhaled NO and the severity of the inflammatory process in ALI will require further studies.

Acute Disease↗
PubMed2003

Planning, simulation, and augmented reality for robotic cardiac procedures: The STARS system of the ChIR team.

This paper presents STARS (Simulation and Transfer Architecture for Robotic Surgery), a versatile system that aims at enhancing minimally invasive robotic surgery through patient-dependent optimized planning, realistic simulation, safe supervision, and augmented reality. The underlying architecture of the proposed approach is presented, then each component is detailed. An experimental validation is conducted on a dog for a coronary bypass intervention using the Da Vinci(TM) surgical system focusing on planing, registration, and augmented reality trials.

Animals↗
PubMed2002

Reflex regulation during sustained and intermittent submaximal contractions in humans.

To investigate whether the intensity and duration of a sustained contraction influences reflex regulation, we compared sustained fatiguing contractions at 25 % and 50 % of maximal voluntary contraction (MVC) force in the human abductor pollicis brevis (APB) muscle. Because the activation of motoneurones during fatigue may be reflexively controlled by the metabolic status of the muscle, we also compared reflex activities during sustained and intermittent (6 s contraction, 4 s rest) contractions at 25 % MVC for an identical duration. The short-latency Hoffmann(H) reflex and the long-latency reflex (LLR) were recorded during voluntary contractions, before, during and after the fatigue tests, with each response normalised to the compound muscle action potential (M-wave). The results showed that fatigue during sustained contractions was inversely related to the intensity, and hence the duration, of the effort. The MVC force and associated surface electromyogram (EMG) declined by 26.2 % and 35.2 %, respectively, after the sustained contraction at 50 % MVC, and by 34.2 % and 44.2 % after the sustained contraction at 25 % MVC. Although the average EMG increased progressively with time during the two sustained fatiguing contractions, the amplitudes of the H and LLR reflexes decreased significantly. Combined with previous data (Duchateau & Hainaut, 1993), the results show that the effect on the H reflex is independent of the intensity of the sustained contraction, whereas the decline in the LLR is closely related to the duration of the contraction. Because there were no changes in the intermittent test at 25 % MVC, the results indicate that the net excitatory spinal and supraspinal reflex-mediated input to the motoneurone pool is reduced. This decline in excitation to the motoneurones, however, can be temporarily compensated by an enhancement of the central drive.

Action Potentials↗
PubMed2002

Frequency, predictors, and consequences of atrioventricular block after mitral valve repair.

This study examines the incidence, predictors, and evolution of postoperative atrioventricular block (AVB) after mitral valve repair (MVR) in 115 consecutive patients using Carpentier's technique (between November 1996 and April 1997). Postoperative AVB occurred in 27 patients (23%). Third-degree AVB was found in 7 patients (6%) in the immediate postoperative period, but in 4 it was transient, resolving partially or completely before the seventh postoperative day. Second-degree AVB (Mobitz type I) occurred in 4 patients (3%) immediately after operation and resolved in all before hospital discharge. Isolated first-degree AVB occurred in 16 patients (14%) and was permanent in 12. Neither the preoperative variables nor the mitral procedures including anterior versus posterior leaflet repair were related to postoperative AVB. A lesser systemic hypothermia during surgery was the only, modestly independent predictor of postoperative AVB (odds ratio 1.53; 95% confidence interval 1.04 to 2.25; p = 0.031). Three patients (2.6%) had permanent pacemaker implantation, on average 18 days after operation, and all had persistent third-degree AVB. With a mean follow-up of 3 years, no recurrence or worsening of conduction disturbances, no further pacemaker implantation, and no late deaths were observed.

Adolescent↗
PubMed2002

Human leukocyte antigen-G expression after heart transplantation is associated with a reduced incidence of rejection.

BACKGROUND: Human leukocyte antigen (HLA)-G, a nonclassic major histocompatibility complex class I molecule expressed in the extravillous cytotrophoblast at the feto-maternal interface, is known to protect the fetus from maternal cellular immunity. In a preliminary study, we showed that HLA-G is expressed in the hearts of some patients after heart transplantation. METHODS AND RESULTS: In the present study, a larger number of patients was investigated to confirm this finding and to look for possible correlations between HLA-G expression and the number and types of rejection. Expression of HLA-G in endomyocardial biopsy specimens was investigated by immunohistochemical analysis, and detection of the soluble HLA-G in the serum was performed by immunoprecipitation followed by Western blot analysis. HLA-G was detected in the biopsy specimens and serum of 9 of 51 patients (18%). The number of episodes of acute rejection was significantly lower in HLA-G-positive patients (1.2+/-1.1) as compared with HLA-G-negative patients (4.5+/-2.8) (P<0.001). No chronic rejection was observed in HLA-G-positive patients, whereas 15 HLA-G-negative patients had chronic rejection (P<0.032). A longitudinal study of these patients reveals that the status of HLA-G expression was maintained after 6 months both in serum and in biopsy specimens. During this period, HLA-G-positive patients did not have chronic rejection. CONCLUSIONS: There is a significant correlation between rejection and HLA-G expression in the heart after transplantation. HLA-G expression and its effect in reducing the incidence and severity of rejection seem to be stable throughout the evolution.

Adult↗
PubMed2002

Treatment of heart failure with autologous skeletal myoblasts.

BACKGROUND: The management of patients with heart failure is a daily challenge for cardiologists and cardiac surgeons. Pharmacotherapy, atrio-biventricular resynchronization, myocardial revascularization, valve repair techniques, latissimus dorsi cardiomyopathy, acorn cardiac support device, heart transplantation and mechanical assist devices do not cover all the needs. The recent progress in cellular and molecular biology allows the development of new therapies for heart failure. TRANSPLANTATION OF AUTOLOGOUS CELLS: One of the most innovative consists in the transplantation of autologous ex-vivo expanded cells into the myocardium for heart muscle regeneration. This approach is called "cellular cardiomyoblasty".

Animals↗
PubMed2002

Triple valve repair for young rheumatic patients.

BACKGROUND: Facing young foreign polyvalvular rheumatic patients, for which long-term anticoagulation is not available, we have chosen to attempt triple valve repair procedures in order to avoid prosthetic implantation in this particular population suffering from triple valve disease. METHODS: Twenty-one young rheumatic patients (mean age:11+/-4 years) underwent triple valve repair procedures including cusp extension on the aortic valve aortic between September, 1992 and December, 2000. Valvular pathology characteristics according to Carpentier's classification included mitral insufficiency type III post+II ant (n=10), type III post (n=4), type II ant (n=2), mitral stenosis (n=5), type III aortic insufficiency (n=21), type I (n=13) and type III (n=8) tricuspid insufficiency. RESULTS: Firstly, the mitral valve disease were corrected using Carpentier's techniques of repair: prosthetic ring annuloplasty (n=16), commissurotomy (n=12), chord transposition (n=11) or shortening (n=4), papillary muscle sliding plasty (n=4) and pericardial patch leaflet enlargement (n=6). Secondly, aortic lesions were corrected using glutaraldehyde stabilized autologous pericardium triple cusps extension technique (n=21). Lastly, tricuspid repairs were always performed on beating hearts using commissurotomy (n=8), prosthetic ring (n=12) or other techniques (n=9) of annuloplasty. The operative mortality was 4.7% (one patient died). Echocardiograms before discharge showed grade I mitral insufficiency in seven patients and grade I aortic insufficiency in five patients. There was no late death during a mean follow-up of 51+/-31 months. Two patients underwent valvular redo surgery because of aortic and mitral plasty deterioration due to rheumatic disease progress. After 5 years, 90% of the patients were free from redo valvular surgery. CONCLUSIONS: In rheumatic patients, autologous pericardial patch extension of the aortic valve permitted widespread use of reconstructive surgery even in patients suffering from triple valve disease. Triple valve repair, in this particular challenging setting of patients, has provided satisfactory initial and mid-term results and could be considered as an interesting palliative surgical approach.

Child↗
PubMed2002

[Planning and simulation of minimally-invasive robotic heart surgery].

Due to their numerous advantages, mainly in terms of patient benefit, mini-invasive robotically assisted interventions are gaining in importance in various surgical fields. However, this conversion has its own challenges that stem from both its novelty and complexity. In this paper we propose to accompany the surgeons in their transition, by offering an integrated environment that enables them to make better use of this new technology. The proposed system is patient-dependent, and enables the planning, validation, simulation, teaching and archiving of robotically assisted interventions. The approach is illustrated for a coronary bypass graft using the daVinci tele-operated robot.

Cardiac Surgical Procedures↗
PubMed2002

Robotic-assisted cardiac surgery: anesthetic and postoperative considerations.

OBJECTIVE: To assess the feasibility of endoscopic telemanipulated cardiac surgery and describe the anesthetic, postoperative, and surgical implications of minimally invasive robotic-assisted cardiac surgery. DESIGN: Prospective study. SETTING: Cardiovascular and transplant center, university hospital. PARTICIPANTS: Twenty patients (13 men, 7 women) scheduled for either coronary artery bypass graft surgery or valve surgery. Mean age was 53 +/- 5 years (range, 31 to 75 years) and mean New York Heart Association class was 2.4. Three patients (6 %) were having redo procedures, and 1 patient had bacterial endocarditis. INTERVENTIONS: Surgery was done with the aid of the daVinci surgical robot (Intuitive Surgical, Mountain View, CA). Induction and maintenance of anesthesia consisted of a target-controlled infusion of remifentanil and propofol. In 11 cases (55%), cardiopulmonary bypass was performed with Port-Access technology (Heartport, Redwood City, CA), and in the remaining 9 cases (45%), conventional femorofemoral bypass was used. MEASUREMENTS AND MAIN RESULTS: Fifteen patients (75 %) were extubated within 6 hours and discharged from the cardiac surgery intensive care unit on postoperative day 1. Two patients (10%) were reexplored in the immediate postoperative period. Two conversions to thoracotomy were reported. One reoperation at 6 months and 1 late death occurred. At 1-year follow-up, excellent functional results were observed in 18 cases. CONCLUSION: Caution should be used when assessing innovative medical-surgical techniques. Despite technical difficulties and lengthy procedures, results were satisfactory. The feasibility of robotic-assisted surgery for coronary artery bypass graft and valve procedures is intuitively appealing.

Adult↗
PubMed2002

Exhaled nitric oxide does not reflect the severity of acute lung injury: an experimental study in a rat model of extracorporeal circulation.

OBJECTIVE: This study was undertaken to determine whether an increase in exhaled nitric oxide would reflect the severity of the acute lung injury caused by extracorporeal circulation. DESIGN: Prospective, controlled animal laboratory investigation. SETTING: University laboratory. SUBJECTS: Male, anesthetized, paralyzed, and mechanically ventilated Wistar rats (n = 34). INTERVENTIONS: Twenty-three Wistar rats underwent a partial (100 mL.kg(-1).min(-1)) femoro-femoral extracorporeal circulation in normothermia for 90 mins. Eleven time-matched rats formed the sham group. MEASUREMENTS AND MAIN RESULTS: Exhaled nitric oxide was monitored with a chemiluminescence analyzer. Acute lung injury was assessed by blood gas analysis and lung water content. Lung Evans blue dye content, lung myeloperoxidase, and heme oxygenase activities were determined. Compared with the sham rats, extracorporeal circulation was responsible for acute lung injury characterized by an increased lung water content (82.4 +/- 1.3% vs. 77.9 +/- 1.1%; p<.05), an increased Evans blue dye content (191.8 +/- 15.8 vs. 112.5 +/- 16.8 mg/g tissue wet weight; <.01), and an increased pulmonary heme oxygenase activity (332.9 +/- 107 vs. 113.7 +/- 46.5 pmol. hr(-1).mg of protein(-1); p<.05). Exhaled nitric oxide remained stable throughout the experiment in all sham rats. Among the 23 rats that underwent extracorporeal circulation, eight rats (35%) experienced an increase in exhaled nitric oxide concentration (16.9 +/- 12.7 ppb). There was no significant difference between rats that did or did not experience an increase in exhaled nitric oxide regarding each index of acute lung injury. CONCLUSIONS: An increase in exhaled nitric oxide did not reflect the severity of the acute lung injury caused by extracorporeal circulation. Its significance remains to be determined.

Animals↗
PubMed1999

Mitral valve repair in children using Carpentier's techniques.

Controversy remains regarding whether valve repair is preferable to valve replacement in children suffering from rheumatic mitral valve disease. To answer this question, 130 children aged 3 to 15 years (mean age, 11.8 +/- 2.8 years) undergoing surgery between January 1992 and December 1997 using Carpentier's techniques were reviewed. There were 111 cases of rheumatic valve diseases (85%), 17 cases of congenital mitral valve malformations (13%), one case of Barlow's syndrome (1%), and one case of bacterial endocarditis (1%). Valve dysfunction was classified into three types according to Carpentier's classification. There were 14 type II (leaflet prolapse), 78 type III (restricted leaflet motion), and 38 associated type II (anterior leaflet) and III (posterior leaflet) cases. There was one early (in-hospital) death (0.7%); the remaining 129 children were examined every 6 months. At the last examination, 99.2% of the patients were still alive, 96.8% were free of reoperation, and 89% showed no sign of significant residual stenosis or insufficiency on echocardiography. There have been no thromboembolisms. We conclude that mitral valve repair using Carpentier's techniques is the preferred procedure in the surgical treatment of mitral valve incompetence in children, even in those with rheumatic valvular disease. Copyright 1999 by W.B. Saunders Company

Journal Article↗
PubMedDate not supplied

Induction of chronic cardiac insufficiency by arteriovenous fistula and doxorubicin administration.

OBJECTIVES: Large animal experimental models of chronic heart failure (HF) permit repeated invasive assessment of cardiovascular function, and evaluation of new medical or surgical therapies. The existing models however fail to achieve stable and long-term HF. The aim of this study was to create a simple and stable chronic model of HF in goat, using both arteriovenous fistula and weekly intravenous doxorubicin injections. METHODS: After a preliminary experiment on four goats receiving weekly 1 to 2 mg/kg of doxorubicin, six adult female goats, having had an arteriovenous fistula without signs or symptoms of heart failure, received weekly two different dosages of doxorubicin for 13 weeks: group A (n = 3) received 0.5 mg/kg and group B (n = 3) received 1 mg/kg. After a three-month period without medication, both groups received again 1 mg/kg for four weeks. Cardiac function was assessed by repeated electrocardiographic and echocardiographic examinations. RESULTS: Four goats died during the medication period (one in group A, three in group B). During the period without medication a stable ventricular hypocontractility with left ventricular dilation was observed. Left ventricular dysfunction was more pronounced in group B, and was associated with clinical symptoms of HF. CONCLUSIONS: Arteriovenous fistula alone did not produce HF. Its association with doxorubicin injections provides a simple and stable chronic model of HF. This association allows reduction of the required doxorubicin dose and toxicity in animals and in the environment. Depending of the dose of doxorubicin, it is possible to obtain a model of heart dilatation and ventricular hypokinesia with or without clinical symptoms of HF, with a different mortality.

Animals↗
PubMedDate not supplied

From dynamic to cellular cardiomyoplasty.

Dynamic Cardiomyoplasty. Latissimus dorsi dynamic cardiomyoplasty has been used in our institution for heart failure patients refractory to medical therapy; 113 cases were operated at Broussais and Pompidou Hospitals and 75 patients by our team abroad, in the scope of an international cooperative program. Cardiomyoplasty has been associated with better results due to technical improvements, the most significant mini-invasive techniques, the latest the use of growth factors to enhance muscle vascularization. Risk factors have been identified, resulting in more precise indications, a lower hospital mortality, and a wider use of this operation. There has been a new tendency to associate cardiomyoplasty with electrophysiological therapies: implantation of ventricular defibrillators and multisite cardiac pacing (for atrioventricular and interventricular resynchronization). Cellular Cardiomyoplasty. Adult myocardium cannot repair after infarction due to the absence of stem cells. Cell transplantation strategies for heart failure have been designed to replace damaged cells with cells that can perform cardiac work. Current possibilities in cell therapy for heart failure is the transplantation into the infarcted myocardium of autologous myoblasts (satellite cells originated from skeletal muscle), fetal cardiomyocytes, autologous heart cells, cells derived from bone marrow stem cells, and smooth muscle cells. Experimental studies demonstrated that cell transplantation into the myocardium was associated with the recovery of myocardial contractility and compliance, as well as the diastolic pressure-strain relationship in animal models (infarctlike myocardial lesions and dilated cardiomyopathy models). Healthy myoblasts and myotubes were observed 2 months after myocardial implantation. Clinical studies are now in progress.

Cardiac Surgical Procedures↗