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C Latremouille

Publications and source records attributed to C Latremouille.

At least 19 recordsLinked to original sources
PubMed2005

In vitro speed of sound measurement at intact human femur specimens.

Quantitative ultrasound has been recognized as a useful tool for fracture risk prediction. Current measurement techniques are limited to peripheral skeletal sites. Our objective was to demonstrate the in vitro feasibility of ultrasonic velocity measurements on human proximal femur and to investigate the relationship between velocity and bone mineral density (BMD). Sound velocity images were computed from 2-D scans performed on 38 excised human femurs in transmission at 0.5 MHz. Different regions-of-interest were investigated. Dual x-ray absorptiometry scans have been achieved for BMD measurements in site-matched regions. Our study demonstrates the feasibility of ultrasonic velocity measurements at the hip with reasonable precision (coefficient of variation of 0.3%). The best prediction of BMD was reached in the intertrochanter region (r(2) = 0.91, p < 10(-4)), with a residual error of 0.06 g/cm(2) (10%). Because BMD measured at the femur is the best predictor of hip fracture risk, the highly significant correlation and small residual error found in this study suggest that speed of sound measurement at the femur might be a good candidate for hip fracture risk prediction.

Absorptiometry, Photon↗
PubMed2004

In vitro ultrasound measurement at the human femur.

Measurements of broadband ultrasonic attenuation (BUA) represent an established means of skeletal status assessment in osteoporosis. Today, the skeletal site that is the most widely used clinically is the calcaneus (heel bone). However, we hypothesized that fracture risk predictions could be improved if ultrasound measurements were performed directly at the main site of fracture, e.g., the proximal femur. The goal of this paper is to demonstrate in vitro the feasibility of quantitative ultra sound (QUS) imaging at the upper part of fee femur, and to investigate the relationships of BUA to bone mineral density (BMD). Forty-four excise human femurs were measured in transmission with a pair of focused 0.5-MHz central frequency transducers. Two-dimensional scans were performed, and the radio frequency (rf) signals were recorded at each measurement point. A data acceptance criterion for region of interest (ROI) selection was established based on the linearity of the frequency-dependent attenuation. Five measurements with repositioning were performed on each sample to determine the reproducibility. Dual energy x-ray absorptiometry (DXA) scans have been performed on the samples for BMD measurements: Three ROIs were selected in the specimens: greater, trochanter intertrochanteric, and femoral neck regions. Coefficient of variations were in the range 1.6% to 2.5%. The determination coefficients (r(2)) between BUA and BMD in site-matched ROIs were 0.81, 0.78, and 0.73, respectively, for the greater trochanteric, intertrochanteric, and femoral neck regions. Our results are consistent with data previously shown at the calcaneus and demonstrate the feasibility of QUS measurements at the femur in vitro, with reasonable reproducibility.

Absorptiometry, Photon↗
PubMed2001

Left ventricular reconstruction after resection of a large fibroma.

Cardiac fibromas are rare tumors that are histologically benign but potentially lethal because of their location. The prognosis is related to complete resection. We report the case of a 15-year-old boy who, 1 year after partial excision of a large fibroma, underwent successful complete resection through a conventional surgical approach with left ventricular reconstruction.

Adolescent↗
PubMed2001

[Effect of aortic valve replacent for aortic stenosis on cervical arterial blood flow].

Aortic stenosis is known to modify initial upstroke time (IUT) of velocity in peripheral arteries and carotid velocities. The authors conducted a prospective study in 30 patients scheduled for aortic valve replacement for aortic stenosis. The goal was to establish postoperative correction of carotid flow disorders. In the preoperative period, a positive correlation (p < 0.01) was observed between IUT and mean pressure gradient, and a negative correlation (p < 0.02) between IUT and aortic valve area. Post-operatively, the authors observed a large decrease (p < 0.0001) of IUT, and higher (p < 0.05) systolic peaks of velocity (PSV) in all studied arteries. In this article, the authors confirmed the few previous studies which described preoperative velocity modifications in aortic stenosis population, but they also described for the first time their postoperative correction. Therefore, identifying these patterns of peripheral circulatory alterations is important and underestimation of carotid stenosis, currently estimated preoperatively, must be avoided.

Adult↗
PubMed2000

[Cardiac fibroelastoma. Six operated cases and review of the literature].

The authors reviewed the cases of 6 patients operated between September 1994 and February 1999 for a rare benign tumour: papillary fibroelastoma of the heart. These patients, aged 51 +/- 14 years, all have single valvular involvement: mitral (N = 3), aortic (N = 2), tricuspid (N = 1). Five patients were symptomatic: transient ischaemic cerebral events (N = 3) associated with mesenteric infarction requiring ileal resection in 1 case; constituted cerebrovascular accident (N = 1); syncope (N = 1). In this last patient, the fibroelastoma was diagnosed fortuitously on the tricuspid valve. The features and location of the tumours were determined by transoesophageal echocardiography. Surgical treatment in all patients consisted in excising the tumour and preserving the valve. One aortic cusp was reconstructed after excising the tumour with a cryopreserved partial aortic homograft. Peroperative transoesophageal echocardiography confirmed the absence of regurgitation after the procedures in all patients. There were no postoperative complications in any of the cases. No cases of valvular regurgitation or of tumour recurrence were observed during follow-up. Despite the benign histology, cardiac fibroelastomas should be excised because of their embolic complications. Absence of recurrence justifies conservative reconstruction of the affected valve.

Adult↗
PubMed2000

[Left ventricular reconstruction after excision of a large fibroma].

The authors report the case of a 15 year old boy with a large left ventricular fibroma discovered after a series of syncopal episodes due to obstruction to ejection. The first attempt to remove the fibroma in Columbia was only partially successful. In view of the risk of death associated with this type of tumour, it was decided to offer the patient complete excision after a full morphological and functional evaluation of myocardial function and the consequences of the tumour on mitral valve function and on the coronary circulation. The operation was performed under cardiopulmonary bypass and aortic clamping by conventional surgery, associated with reconstruction of the cardiac free wall with a large patch of autologous pericardium which was necessary to avoid cardiac transplantation, the ultimate sanction in this indication.

Adolescent↗
PubMed1999

[The pericardium: a heterogeneous tissue. Anatomic and morphometric considerations].

BACKGROUND AND AIMS OF THE STUDY: Short-term glutaraldehyde fixed autologous pericardium is widely used in cardiac valve repair or in autologous pericardial bioprosthesis construction. The thinner the tissue, the better the fixation. The aim of this study was to determine thickness and useful surface area of pericardium in relation to harvesting site using a digital thickness counter (0.01 mm precision). Parietal pericardium fragments were obtained from the pericardial sac of six fresh cadavers (group I). In the other groups, pericardial strips (80 x 30 mm) were obtained from patients undergoing surgery: group II patients (n = 5 females) and group III (n = 10 males) were non-cardiomegalic (cardiothoracic ratio (CTR) < 0.5)), while group IV patients (n = 5) were all cardiomegalic (CTR > 0.5). Results were reported on a coloric scale according to measurement position. In group I, mean surface area was 93 +/- 18 cm2, and thickness gradually increased from 0.1 to 0.6 mm, maximally on the diaphragm, along the left heart side. In other groups, a gradual increase in thickness was identified towards the diaphragmatic zone. Significant differences in tissue thickness appear as a result of cardiomegaly, but are not related to the sex of the patients. Pericardium taken from the right anterior aspect of the pericardial sac in patients without cardiomegaly is the most appropriate tissue for valve reconstructive surgery, due to its thin nature and hence better fixation properties.

Analysis of Variance↗
PubMed1998

Intravenous immunoglobulins for therapeutic use contain anti-idiotypes against xenophile antibodies and prolong discordant graft survival.

Xenotransplantation between discordant species leads to a graft survival of a few minutes, due to binding of natural antibodies to the xenogeneic endothelial cells, complement activation, and endothelial cell activation. Polyclonal human immunoglobulins for intravenous use (IVIg) from normal donors have been proven effective in a variety of antibody-mediated disorders and contain anti-idiotypic antibodies directed against a number of disease-associated and natural antibodies. We have shown that administration of IVIg delays rejection of a guinea pig heart to a rat. We demonstrate herein that IVIg can inhibit the binding of xenoreactive rat IgG antibodies to guinea pig endothelial cells. This inhibition is likely due to the presence, among IVIg, of anti-idiotypic antibodies as F(ab')2 fragments of IVIg were as effective as whole IVIg. In addition, natural anti-endothelium rat antibodies were retained on a column of F(ab')2 fragments of IVIg coupled to Sepharose. The degree of inhibition of binding of IgG natural antibodies correlated with the survival of the xenograft when IVIg was administered prior to transplantation. Thus IVIg prolong xenograft survival through idiotypic-anti-idiotypic interactions with natural xenoreactive antibodies of the IgG isotype.

Animals↗
PubMed1997

Normal human immunoglobulins for intravenous use (IVIg) delay hyperacute xenograft rejection through F(ab')2-mediated anti-complement activity.

Xenotransplantation between discordant species leads to a hyperacute rejection mediated by natural antibodies, both of the IgG and IgM isotypes, activation of complement and endothelial cell activation. The combination of these mechanisms leads to a transplant survival of minutes to a few hours. Polyclonal human immunoglobulins for intravenous use (IVIg) from normal donors have proved effective in a number of antibody-mediated disorders, as well as in inflammatory disorders. We demonstrate that administration of IVIg in a guinea pig to rat model of cardiac xenografting can effectively delay hyperacute rejection. This effect is mediated by the F(ab')2 fragments of IVIg, and is correlated to an anti-complementary activity.

Acute Disease↗
PubMed1993

Cardiac hemangiomas.

Cardiac hemangiomas are rare benign vascular tumors of the heart. To date, 23 cases have been reported. Symptoms are usually due to compression of cardiac structures or obstruction of outflow tracts. Echocardiography usually directs the diagnosis toward a cardiac mass. Enhanced-contrast computed tomographic scan or magnetic resonance imaging establishes the diagnosis of hypervascularized cardiac tumor. Coronary arteriography establishes the diagnosis by showing the characteristic tumor blush. Surgical resection is done using cardiopulmonary bypass. Long-term outcome is favorable.

Adult↗
PubMed1993

Left ventricular outflow tract obstruction after mitral valve repair. Results of the sliding leaflet technique.

BACKGROUND: Left ventricular outflow tract obstruction (LVOTO) occurs in 4% to 5% of patients after prosthetic ring mitral valve repair. Major anatomic factors incriminated in the genesis of LVOTO include degenerative mitral valve insufficiency with excess leaflet tissue, nondilated left ventricular cavity, and narrow mitro-aortic angle. We have previously reported a 14% incidence of LVOTO after prosthetic ring mitral valve repair in this high-risk group of patients. Serial echo Doppler studies demonstrated an overlapping and/or inversion of the left ventricular functional compartments generating systolic anterior motion of the posterior leaflet and paradoxical opening (eversion) of the anterior leaflet. In an attempt to eliminate LVOTO after mitral valve repair, a new surgical procedure was developed in 1988 by Carpentier: the sliding leaflet technique, which reduces the height of the posterior leaflet. The purpose of this study was to analyze the results of the new technique in terms of the occurrence of LVOTO: METHODS AND RESULTS: Eighty-two patients undergoing prosthetic ring mitral valve repair between 1988 and 1991 and identified as high risk for LVOTO were operated on using the sliding leaflet technique. There were 52 men and 30 women. Ages ranged from 28 to 75 years. The surgical techniques used included prosthetic ring annuloplasty (n = 82), leaflet resection (n = 82), chordal shortening or transposition (n = 36), and other (n = 19). Intraoperative and/or immediate postoperative echo Doppler studies were obtained in all cases. Two patients (2.4%) died, and 2 (2.4%) required reoperation. Nonsignificant LVOTO was identified in 2 cases (2.4%), in whom instantaneous maximal subaortic gradients were 20 and 18 mm Hg, respectively. CONCLUSIONS: This study was not done on a concomitant series of patients but on patients with the same type of pathology. It demonstrates that (1) the sliding leaflet technique eliminates significant LVOTO in the high-risk patients; (2) the sliding leaflet technique is associated with a low mortality; and (3) no reoperations for mitral insufficiency were required in this series.

Echocardiography, Transesophageal↗
PubMed1990

Dynamic aortomyoplasty to assist left ventricular failure.

The efficacy of skeletal muscle contractile force to augment left ventricular function has been demonstrated experimentally and clinically by the cardiomyoplasty procedure. Another approach in biomechanical cardiac assistance is the use of electrostimulated skeletal muscle in an extracardiac position. We describe an autologous counterpulsating device using the native ascending aorta as a ventricular chamber wrapped by an electrostimulated latissimus dorsi muscle flap (LDMF). This model avoids thrombotic complications observed in skeletal muscle neo-ventricles associated with prosthetic chambers. In 8 goats, a right LDMF was transferred to the thoracic cavity by removal of the second rib. In 4 goats, the diameter of the aorta was enlarged by surgical implantation (using lateral clamping) of an autologous pericardial patch. The LDMF was wrapped around the ascending aorta and electrostimulated using an external diastolic pulse generator connected to a sensing myocardial lead and to LDMF pacing electrodes. Hemodynamic studies were performed (left ventricular, aortic, and pulmonary artery pressures and rate of rise of left ventricular pressure). The LDMF diastolic counterpulsation was performed using a burst of 30 Hz, with a delay from the R wave adjusted to provide optimal diastolic augmentation. Percent increase in the subendocardial viability index was calculated during unassisted and assisted cardiac cycles (1:2) at baseline and after acute heart failure induced by the administration of high doses of propranolol hydrochloride (3 mg/kg intravenously). Diastolic aortic counterpulsation by the stimulated LDMF resulted in a significant improvement in the subendocardial viability index both at baseline and after induced cardiac failure in both groups, though the increase was greater in the group with aortic enlargement.

Animals↗
PubMed1990

Absorbable rings for pediatric valvuloplasty. Preliminary study.

Secondary valvular stenosis is a significant risk of annular ring implantation during valvular repair in children. To avoid this problem, we have developed an absorbable prosthetic ring (APR), which induces the generation of a biologic fibroelastic ring with mitotic capability and thereby allows atrioventricular annulus growth with age. Twelve polydioxanone (PDS) biodegradable APRs were surgically implanted in immature goats. To avoid possible embolic complications from ring fragments during the absorption period, APRs were covered with an extensible sewing sheath of high-porosity polyester, allowing contact between the PDS, blood, and endocardium. Four APRs were implanted into the right atrial cavity, four in the tricuspid position, and four in the mitral position. Histological studies at 6 months showed a considerable amount of remaining PDS. At 1 year, only small residual fragments of PDS were present, surrounded by collagen and elastic fibers as well as fibroblasts with mitotic activity. This histological structure represents a new biologic fibroelastic ring, which has originated from PDS rings. Echocardiography at 12 months showed that the elasticity of APRs and fibrotic tissue allows normal systolic and diastolic valve motions. These findings, which demonstrate histological changes in native valve annuli as well as stable and elastic annuloplasty without secondary stenosis in growing animals, call for new studies involving hearts with valvular disease.

Animals↗
PubMed1990

Atrial cardiomyoplasty after Fontan-type procedures.

The purpose of right atrial cardiomyoplasty is to increase atrial-pulmonary flow in patients undergoing Fontan-type procedures. We developed two surgical techniques to bypass the right ventricle, followed by right atrial cardiomyoplasty with a stimulated latissimus dorsi muscle flap (LDMF). In 10 goats, the left LDMF was transferred into the chest by removal of the second rib. After sternotomy, the right atrial appendages of five goats (group 1) were connected to the distal main pulmonary artery with polytetrafluoroethylene tubing and the proximal pulmonary trunks were ligated. In the other five goats (group 2), under cardiopulmonary bypass, bioprosthetic valves were implanted into the inferior venae cavae. The tricuspid orifice was closed, and the atriopulmonary connection was performed. The left LDMF was sutured over the right atrium and stimulated using synchronous 30-Hz bursts of impulses delivered by a Medtronic Cardiomyostimulator. Hemodynamic studies were performed in the acute phase. Right atrial, pulmonary arterial, and aortic pressures were assessed. Cardiac output was measured using ultrasonic flow studies. LDMF stimulation restored pulsatile pressure patterns in the pulmonary artery and increased the cardiac output. These observations were more evident in the model with caval valvular implant. This functional "ventricularization" of the right atrium could improve long-term results after Fontan-type procedures and extend operative indications. Chronic experimental studies are necessary to evaluate the diastolic and systolic functions of the neo-right ventricle.

Animals↗