Biomedical subjects

François Laborde

Publications and source records attributed to François Laborde.

At least 19 recordsLinked to original sources

PubMed2006

Expandable right ventricular-to-pulmonary artery conduit: an animal study.

This study was performed to assess a new vascular stent graft as an expandable valved conduit for right ventricular outflow tract (RVOT) reconstruction in sheep. Conduits were constructed by sewing an 18-mm valved conduit inside a stent. Crimped to 16 mm, they were implanted either under or without extracorporeal circulation in seven (group A) and in five (group B) sheep, respectively. Six weeks and 3 mo after their insertion, conduits were dilated intraluminally. A valved stent was implanted percutaneously into conduits before they were killed. Two animals from group A recovered normally, whereas five animals had a complicated postoperative course. In group B, one died acutely due to kinking of the conduit. Balloon dilatations were performed in all surviving animals. First dilatations had a slight impact on valvular function in all animals but one, whereas second dilatations led to significant PR in all. Transcatheter valve implantation was performed successfully. When animals were killed, no bleeding was found around the surgically implanted device. In conclusion, we designed a biologic valved conduit for RVOT reconstruction that can be dilated sequentially to follow animal growth. This new device can have tremendous applications in children with congenital heart diseases involving the RVOT.

Animals↗

PubMed2006

Mitral valve repair robotic versus sternotomy.

OBJECTIVE: Robotically assisted mitral valve repair were compared with sternotomy mitral valve repair. Prospectively we evaluated safety and efficacy in performing simple mitral repairs. METHODS: Between February 2004 and September 2005, 25 patients with posterior leaflet insufficiency underwent mitral valve repair using the da Vinci system. They were matched retrospectively with 25 patients who underwent the same repair via a median sternotomy. The minimal invasive repairs were performed with peripheral cardiopulmonary bypass, transthoracic aortic cross-clamp, and antegrade cardioplegia. Repair was performed with two ports and a 4-cm intercostals lateral incision in the right chest for access. All patients had posterior leaflet resection and placement of a ring annuloplasty. RESULTS: All patients had successful valve repairs. There were no deaths. There was one conversion to an extended thoracotomy in the minimal invasive group due to a bleeder on the left atrial appendage. Overall mean study times showed a longer aortic cross-clamp (range, 96.1 min vs 69.6 min) and cardiopulmonary bypass (range, 122.1 min vs 85.7 min) for the minimal invasive group. Length of stay was less for the minimal group (7 days vs 9 days). At postoperative echocardiography two patients in both group developed 2+ mitral regurgitations. All other patients had a competent mitral valve repair with no insufficiency. CONCLUSIONS: Simple mitral valve repair can be successfully performed with the da Vinci robotic system. This approach is as safe as a sternotomy and long-term follow-up is needed to determine the durability of the mini invasive repair.

Aged↗

PubMed2006

Video-assisted thoracoscopic clipping of patent ductus arteriosus: close to the gold standard and minimally invasive competitor of percutaneous techniques.

OBJECTIVE: To review our 12-year experience in video-assisted thoracoscopic surgery (VATS) for patent ductus arteriosus. METHODS: VATS was performed in 743 patients. Three groups were compared: 24 low-birth-weight infants (LBWIs), 676 children between 2.5-25 kg and 43 boys > 25 kg. A diameter of > 8 mm was the main contraindication. For 85 consecutive patients, hospital stay underwent cost analysis. RESULTS: Median age was 1.6 years (range 5 days-33 years) and median weight 9.0 kg (range 1.2-65 kg). Mortality was nil. Median operative time was 20 min and hospital stay 2 days. Residual patency at discharge was 0% in LBWIs, 0.7% in children, and 4.7% in boys (P = NS) and 0, 0.3, and 4.7% at follow-up (P = 0.001). Persistent recurrent laryngeal nerve dysfunction was recorded in 4.2% of LBWIs, 0.3% of children and 0% of boys (P = 0.012). Total mean cost was Euro 5954 +/- 2110. CONCLUSIONS: The success rate of VATS clipping compares favorably with the thoracotomic approach but without chest wall trauma and it may have a very favorable cost-effective therapeutic balance compared to transcatheter techniques.

Adolescent↗

PubMed2005

Early experience with robotic aortic valve replacement.

We report our initial experience with aortic valve replacement using robotic assistance. All procedures were performed with peripheral cardiopulmonary bypass, transthoracic aortic cross-clamp, and antegrade cold crystalloid cardioplegia. One or two ports and a 5-cm intercostal incision in the right chest were used for access. All patients had aortic valve replacement performed robotically. Between February and September 2004, five patients underwent robotic aortic valve replacement. The mean age was 59 years (range 35-82 years). There were no incisional conversions, death, stokes, or reoperations for bleeding. Overall mean study times were as follows: procedure, 231.2 min (range 180-315 min); cardiopulmonary bypass, 121.5 min (range 83-173 min), and cross-clamp, 98.2 min (range 67-140 min). One patient developed postoperative pneumonia. Aortic valve replacement can be successfully performed with the da Vinci robotic system.

Adult↗

PubMed2005

Cardiac "fitness" training: an experimental comparative study of three methods of pulmonary artery banding for ventricular training.

BACKGROUND: When the left ventricle is unable to sustain a systemic pressure in transposition of the great arteries (TGA), left ventricular retraining is mandatory before the morphologic left ventricle under the aorta is switched. This is currently achieved by creating a ventricular overload through pulmonary artery banding, usually associated with an aortopulmonary shunt in case of a TGA with an intact ventricular septum. Our experimental study compared three different modes of increased ventricular afterload to obtain ventricular hypertrophy. METHODS: Fifteen lambs (mean weight 48 kg) underwent pulmonary artery banding. Five animals (group I) received a classic band; 5 (group II) received a classic band which was adjusted at week 1 and 3; and 4 (group III) received a band which was tightened for 1 hour, twice a day (early morning and late afternoon). After 5 weeks, the lambs were evaluated hemodynamically before they were sacrificed and their hearts harvested for histologic examination. RESULTS: No difference was noted in the hemodynamic data between groups 1 and II. Group III showed a greater ability to increase ventricular pressure in this model. No significant difference was noted between the three groups in terms of macroscopic alterations, but all animals demonstrated an increase in right ventricular wall thickness compared with control animals. Several fibrosis areas were evident in group I and II but none in group III. CONCLUSIONS: Intermittent pulmonary artery banding is able to induce hemodynamically sufficient ventricular hypertrophy without fibrosis.

Animals↗

PubMed2005

Detection of prominent left anterior descending coronary artery stenosis for patients with stable angina using Doppler tissue echocardiography.

The midseptum has an elective left anterior descending coronary artery (LAD) supply. Septal peak velocity (PkV) and myocardial velocity gradient (MVG) were studied at rest with M-mode Doppler tissue echocardiography during the cardiac cycle including the septal active relaxation (SAR) outward wall motion preceding isovolumic relaxation. In all, 33 patients had significant multivessel coronary artery disease. Group A (15 patients) had prominent LAD stenosis. Group B (18 patients) had prominent circumflex (15) or right (3) coronary artery stenoses. The goal was to detect a prominent LAD stenosis. During SAR, sensitivity to detect a prominent LAD stenosis was 86% for PkV < 20 mm/s and 80% for MVG < 1.1 s(-1); specificity was 83% for both variables. During systole, sensitivity was 86% with a 55% specificity for MVG < 2.0 s(-1), whereas sensitivity was 73% and specificity 66% for PkV < 30 mm/s. Areas under receiver operating characteristic curves were over 0.90 during SAR and only 0.70 for PkV and 0.80 for MVG during systole. In multivessel coronary artery disease, SAR variables better identified a prominent LAD stenosis than systolic variables. Moreover, SAR PkVs were informative per se, whereas systole required MVG calculation.

Aged↗

PubMed2005

Noncultured cell transplantation in an ovine model of right ventricular preparation.

OBJECTIVE: Beyond the first 2 months of life, pulmonary artery banding is warranted before two-stage arterial switch operation. The aim of this study was to explore whether myogenic cell transplantation could contribute to right ventricular function during pulmonary artery constriction in an ovine model. METHODS: Sixteen rams were assigned to one of the following groups: group 1, simple pulmonary artery banding (n = 5); group 2, pulmonary artery banding and cell implantation in the right ventricle (n = 7); and group 3, pulmonary artery banding and placebo injection in the right ventricle (n = 4). Hemodynamic assessment with pressure-volume loops was performed on days 0 and 60. The pulmonary artery banding and the injections were achieved through a left fourth intercostal thoracotomy. Autologous myogenic cell implantation was carried out with a noncultured cell preparation, as previously described by our group. Implanted sites were processed with monoclonal antibodies to a fast skeletal-specific isoform of myosin heavy chain (MY32). RESULTS: Skeletal myosin heavy chain expression was detected at 2 months after noncultured cell implantation in all grafted animals. Right ventricular training resulted in statistically significant increased signs of contractility in all three groups. There was no observed difference, however, between the cell therapy group and the other two groups with respect to signs of cardiac function. CONCLUSION: Successful engraftment of noncultured cells into right ventricular myocardium did not translate into a functional benefit that we could demonstrate in our ovine model. Cellular therapy thus is probably not useful to strengthen a left ventricle being retrained through pulmonary artery banding before arterial switch operation. However, cell transplantation may affect the outcome of right ventricular failure long term after atrial switch operation. Although preliminary, this investigation paves the way for further research into cellular cardiomyoplasty, right ventricular failure, and congenital heart disease.

Age Factors↗

PubMed2005

Tissue Doppler echocardiographic and color M-mode estimation of left atrial pressure in infants.

OBJECTIVES: Using recorded flow and tissue Doppler, we evaluated the relation of peak velocity of early transmitral Doppler filling (E)/early diastolic velocity of the lateral mitral annulus (Ea) ratio and of E/flow propagation velocity (Vp) ratio to mean left atrial pressure in infants after surgery for congenital heart disease. DESIGN: Experimental design. SETTING: Pediatric intensive care unit. PATIENTS: Thirty-seven infants aged 4 (3-8) months. INTERVENTIONS: Patients underwent postoperative invasive hemodynamic monitoring with simultaneously obtained Doppler measurements. MEASUREMENTS AND MAIN RESULTS: Values are expressed as median (25th-75th percentiles). Heart rate was 145 (135-157) beats/min. Left atrial pressure was 10 (8-12) mm Hg with E/Ea 16 (12-19) and E/Vp 1.9 (1.3-2.4). E/Ea and E/Vp ratios were higher in patients with left atrial pressure >10 mm Hg (n = 18), than in patients with left atrial pressure < or =10 mm Hg (n = 19) (E/Ea, 16 [15-25] vs. 12 [9-17], p = .01; E/Vp, 2.3 [1.9-2.8] vs. 1.4 [1-1.9]. respectively, p = .001). At a cutoff point of 15, E/Ea sensitivity for left atrial pressure >10 mm Hg was 17 of 18 (94%) with specificity 13 of 18 (72%). At a cutoff point of 2, E/Vp sensitivity for left atrial pressure >10 mm Hg was 15 of 18 (83%) with specificity 16 of 18 (89%). Areas under the receiver operating characteristic curves were 0.76 (E/Ea) and 0.83 (E/Vp). CONCLUSIONS: Doppler ratios might be considered as promising noninvasive tools for left atrial pressure evaluation in infants after cardiac surgery.

Blood Flow Velocity↗

PubMed2004

Pulmonary artery dissection and rupture associated with aortopulmonary window.

A 31-year-old man with uncorrected aortopulmonary window and fixed pulmonary hypertension experienced dissection of the pulmonary artery, rapidly complicated by a fatal spontaneous rupture into the pericardium. In the setting of pulmonary hypertension, the diagnosis of dissection and rupture of the pulmonary artery should be considered in cases of thoracic pain or cardiogenic shock.

Adult↗

PubMed2004

A new Doppler tissue ratio to revisit systole: the pre-ejectional isovolumic to ejectional velocity ratio-application to aging.

Most diagnostic applications of Doppler tissue echocardiography rely on peak (Pk) velocity (V) values of single variables or myocardial V gradient. Whereas age-related changes in diastolic V are well-known, previous Doppler tissue echocardiography studies of systolic function showed no age effect for pre-ejectional (Ej) isovolumic (PEI) and Ej inward wall motion Pk V. In addition to myocardial V gradient, ratios were calculated between PEI and Ej Pk V, and mean V averaged over systole (PEI/Ej V ratios) at each layer of the posterior wall using M-mode color on two control groups: A (27 +/- 5 years) and B (54 +/- 10 years). The only changes were for PEI/Ej V ratios (mean V endocardial 21 +/- 7% vs 34 +/- 20%, P = .01; mean V epicardial 27 +/- 8% vs 40 +/- 18%, P = .006; Pk epicardial V 21 +/- 10% vs 30 +/- 16%, P = .04 for groups A and B, respectively). Correlation versus age were r = 0.52 and P = .005 (mean V endocardial), r = 0.50 and P = .007 (mean V epicardial), and r = 0.32 and P = .03 (Pk epicardial V). PEI/Ej V ratios and mean V studied in separate layers showed that the new systolic approach had advantages over single variable or Pk V to study age-related changes.

Adult↗

PubMed2004

Paediatric video-assisted thoracoscopic clipping of patent ductus arteriosus: experience in more than 700 cases.

OBJECTIVE: To overcome drawbacks of thoracotomy and percutaneous techniques, we have performed video-assisted thoracoscopic surgery (VATS) since 1991 to treat patent ductus arteriosus (PDA). This retrospective study aims to analyse morbidity and outcome in order to add data in the evaluation of minimally invasive operations. METHODS: From September 1991 to March 2003, 703 patients underwent PDA clipping by VATS. The indications for operation were clinically significant patency or failure to close in older children. Diameter >8 mm, previous thoracotomy, calcifications, infection, or aneurysm were contraindications to VATS. In right decubitus, only two thoracostomy incisions (for 5-mm trocars) and a smaller one (for direct hook insertion) were required. In the post-operative stay two echocardiographic controls were scheduled, the first before extubation and the second before discharge. Referring cardiologists assured follow-up. RESULTS: Mean age was 3.0+/-3.8 years (5 days-33 years), mean weight 10.7+/-8.0 kg (1.2-65 kg), and 3.1% of our activity were low birth-weight infants (LBWIs) weighting < or =2.5 kg. Operative and 30-day mortality was nil. Median operative time was 20 min and median stay 2 days. Unfavourable events globally occurred in 6.8% of cases (13.6% of the LBWIs, RR 4.0, CL 95% 1.5-10.4). Recurrent laryngeal nerve injury was noted in 3% (13.6% of the LBWI, RR 5.1, CL 95% 1.6-15), but only 0.4% had long lasting dysfunction. Incidence of chylothorax was 0.6%, thoracotomy 1%, transfusion for bleeding 0.1%, pneumothorax 1.3%. LBWIs were at increased risk for the latter two events. Residual patency was detected immediately in 1.4% (all non-LBWI) and underwent additional surgery. Incidence of residual patency at follow-up was 0.6% (0% LBWI, 0.6% in 2.5-25 kg group, 5.0% in >25 kg group, P=0.001). CONCLUSIONS: This study records a long experience of PDA treatment in a wide range of body size and age. VATS clipping is safe, but LBWIs are at augmented risk of complication. It may be carried out with a high degree of efficacy in all the ductus diameters <9 mm. VATS clipping requires minimal operating time and avoids morbidity related to chest wall trauma, percutaneous vascular access, and intravascular foreign bodies.

Adolescent↗

PubMed2004

Robotic aortic valve replacement: case report.

We have developed a technique that enables robotic aortic valve replacement with port access via a small right anterior thoracotomy and minimally invasive aortic cross clamping. The procedure is performed under video guidance with all the annular sutures placed with the robot. In the case we report, the patient's postoperative course was extremely simple and pain was minimal. We believe that this is the first reported aortic valve replacement using robotic technology and that it opens a new field of application for robotic assisted surgery.

Aortic Valve Insufficiency↗

PubMed2003

Noncultured, autologous, skeletal muscle cells can successfully engraft into ovine myocardium.

BACKGROUND: There is compelling evidence showing that cellular cardiomyoplasty can improve cardiac function. Considering the potential benefit of using noncultured muscle cells (little time, lower cost, reduced risk of contamination), we investigated the feasibility of grafting cells obtained directly after enzymatic dissociation of skeletal muscle biopsies into ovine myocardium. We hypothesized that those noncultured muscle cells would engraft massively. METHODS AND RESULTS: Autologous, intramyocardial skeletal muscle cell implantation was performed in 8 sheep. A skeletal muscle biopsy sample ( approximately 10 g) was explanted from each animal. The sheep were left to recover for approximately 3 hours and reanesthetized when the cells were ready for implantation. A left fifth intercostal thoracotomy was performed, and 10 epicardial injections of the muscle preparation (between 10 and 20 million cells) were carried out. All sheep were euthanized 3 weeks after myocardial implantation. Immunohistochemistry was performed with monoclonal antibodies to a fast skeletal isoform of myosin heavy chain. Skeletal myosin heavy-chain expression was detected in all slides at 3 weeks after implantation in 8 of 8 animals, confirming engraftment of skeletal muscle cells. Massive areas of engraftment (from 2 to 9 mm in diameter) or discrete loci were noted within the myocardial wall. CONCLUSIONS: Our results indicate that noncultured skeletal muscle cells can successfully and massively engraft in ovine myocardium. Thus, avoiding the cell culture expansion phase is feasible and could become a promising option for cellular cardiomyoplasty.

Animals↗

PubMed2003

Carbon-coated stents implanted in porcine iliac and renal arteries: histologic and histomorphometric study.

PURPOSE: To test in a pig model the biocompatibility and effectiveness of carbon-coated renal and iliac artery stent systems during implantation procedures and at different follow-up periods. MATERIALS AND METHODS: Twenty-two miniature pigs received carbon-coated balloon-expandable stainless-steel stents in their renal and iliac arteries. Animals were killed at 7, 30, or 180 days for evaluation of acute, subacute, and chronic biologic response to the implanted devices. Histologic, histomorphometric, and scanning electron microscopy (SEM) analyses were performed to assess inflammatory reaction, endothelialization process, and neointimal growth. RESULTS: Forty-four iliac stents and 42 renal stents were successfully implanted. Mural thrombi were not observed by angiography or histologic examinations. Histologically, no significant inflammatory reaction was detected: the stents appeared covered by a thin monolayer of endothelial cells even at 7-day follow-up. The neointima showed homogeneous growth and moderate thickness at 30-day and 180-day explantations (0.09 mm +/- 0.06 and 0.15 mm +/- 0.13, respectively, for renal arteries; 0.12 mm +/- 0.04 and 0.21 mm +/- 0.12, respectively, for iliac arteries). Internal and external elastic laminae were intact in 82 of 86 cases (95%) of stent-implanted arteries. Histologic validations were obtained with SEM observations for each follow-up group. CONCLUSIONS: This study showed good technical results of deployment of carbon-coated renal and iliac stents and very satisfactory biologic behavior in terms of tissue and hematologic compatibility. The devices do not induce thrombus formation.

Animals↗

PubMed2002

Percutaneous transcatheter implantation of an aortic valve prosthesis for calcific aortic stenosis: first human case description.

BACKGROUND: The design of a percutaneous implantable prosthetic heart valve has become an important area for investigation. A percutaneously implanted heart valve (PHV) composed of 3 bovine pericardial leaflets mounted within a balloon-expandable stent was developed. After ex vivo testing and animal implantation studies, the first human implantation was performed in a 57-year-old man with calcific aortic stenosis, cardiogenic shock, subacute leg ischemia, and other associated noncardiac diseases. Valve replacement had been declined for this patient, and balloon valvuloplasty had been performed with nonsustained results. METHODS AND RESULTS: With the use of an antegrade transseptal approach, the PHV was successfully implanted within the diseased native aortic valve, with accurate and stable PHV positioning, no impairment of the coronary artery blood flow or of the mitral valve function, and a mild paravalvular aortic regurgitation. Immediately and at 48 hours after implantation, valve function was excellent, resulting in marked hemodynamic improvement. Over a follow-up period of 4 months, the valvular function remained satisfactory as assessed by sequential transesophageal echocardiography, and there was no recurrence of heart failure. However, severe noncardiac complications occurred, including a progressive worsening of the leg ischemia, leading to leg amputation with lack of healing, infection, and death 17 weeks after PHV implantation. CONCLUSIONS: Nonsurgical implantation of a prosthetic heart valve can be successfully achieved with immediate and midterm hemodynamic and clinical improvement. After further device modifications, additional durability tests, and confirmatory clinical implantations, PHV might become an important therapeutic alternative for the treatment of selected patients with nonsurgical aortic stenosis.

Amputation, Surgical↗

PubMed2002

Aortic pulse pressure and extent of coronary artery disease in percutaneous transluminal coronary angioplasty candidates.

BACKGROUND: Pulse pressure and aortic stiffness are both predictors of coronary artery disease. Whether these parameters are directly related to coronary structural alterations has never been studied. METHODS: From September 1999 to September 2000, the following data were collected from 99 eligible patients: invasive intra-aortic systolic and diastolic blood pressures (BP), extent of coronary artery disease, cardiovascular risk factors, and the incidence of angiographically documented restenosis after coronary angioplasty. RESULTS: In the study population, independent determinants of aortic pulse pressure were age, gender, aortic mean BP, heart rate, and extent of coronary artery disease (r2 = 0.57, P < .0001). In univariate analysis, invasive aortic, but not noninvasive brachial, mean pressure (P = .017) and pulse pressure (P = .027) were significantly associated to the extent of coronary artery disease. In a multiple regression analysis, only male gender (P = .013) and the level of aortic pulse pressure (P = .023) were independently associated with the extent of coronary heart disease. Restenosis was angiographically documented in 11 patients (11%). There was a borderline significant association of restenosis to aortic mean BP (P = .05) and to a past history of multiple previous angioplasties (P = .03). CONCLUSIONS: In this study, aortic pulse pressure was a significant risk factor for the extent of coronary artery disease. There was only a borderline significant association of restenosis to the steady, but not pulsatile, component of aortic BP in the stent era.

Aged↗

PubMed2002

Interruption of patent ductus arteriosus in children: robotically assisted versus videothoracoscopic surgery.

OBJECTIVES: If robotic surgery is to be widely used, the risks must be equivalent to those of standard techniques. This study analyzes the feasibility, safety, and efficiency of a robotically assisted technique for patent ductus arteriosus closure and compares the results with those of the videothoracoscopic technique. METHODS: During 2000, 56 children weighing 2.3 to 57 kg (mean, 12 kg) underwent surgical closure of a patent ductus arteriosus. They were distributed into 2 groups: 28 patients (group 1) underwent the videothoracoscopic technique, and 28 (group 2) underwent a robotically assisted (Zeus; Computer Motion, Inc, Goleta, Calif) approach. Operative and postoperative surgical data were studied. RESULTS: Operative time was significantly higher in the robotically assisted group. One conversion in videothoracoscopy was necessary, but no thoracotomy was required. Three persistent shunts were detected at postoperative echocardiography and were treated by means of application of a new clip with videothoracoscopy (1 in group 1 and 2 in group 2). No permanent laryngeal nerve injury and no hemorrhage were noted. The mean hospital stay was 3 days in both groups. CONCLUSIONS: Robotically assisted closure of a patent ductus arteriosus is comparable with closure by means of the videothoracoscopic technique. However, it requires a longer operative time because of the increment in complexity.

Adolescent↗

PubMed2002

Left main artery dissection during 4 French coronary angiography in elderly patient with severe aortic stenosis: "speedy recovery" using emergency primary stenting.

A 70-year-old woman was referred due to a symptomatic severe calcific aortic stenosis. An iatrogenic dissection of the left main artery with total occlusion and arrest (asystole) occurred during preoperative 4Fr coronography. "Speedy recovery" is achieved with a strategy of percutaneous primary stenting revascularization combined with cardiopulmonary maneuvers.

Aged↗