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Biomedical subjects

A Carpentier

Publications and source records attributed to A Carpentier.

At least 199 records · Page 11Linked to original sources
PubMed1991

[Demonstration of abnormalities of myocardial mitochondrial oxygenation in cardiac graft rejection].

Abnormalities of myocardial metabolism during acute rejection may be due to ischemia to primary metabolic changes related to rejection. An experimental study of heterotopic cardiac transplantation in the rat was undertaken to study myocardial mitochondrial oxidation during acute rejection. The receivers were Lewis rats and the donors Fischer (FL: allograft) or Lewis (LL: isograft) rats. The oxygen consumption of the mitochondria (VO2m) isolated from the transplanted and native hearts was measured by oxygraphy six days after transplantation. Using maleate and glutamate substrates, the VO2m of transplanted hearts was significantly lower than that of native hearts in the two groups of rats (FL, p less than 0.01; LL, p less than 0.01). In addition, the VO2m of FL allograft transplanted hearts was significantly lower than in the LL rats (30 +/- 9 vs 100 +/- 15 nanoatoms of oxygen/min.mg/prot, p less than 0.01) as was the VO2m of the native hearts (FL: 106 +/- 23 vs LL: 164 +/- 26, p less than 0.02). The respiratory control ratio (RCR) was significantly lower in the transplanted than in the native hearts in both the FL and LL groups (p less than 0.05 and p less than 0.01 respectively). The comparison of the RCR in the two groups (FL vs LL) showed no significant difference for transplanted or native hearts. Electron microscopy of transplanted (rejected or not) and native hearts showed no morphological abnormality of the mitochondria. The lower VO2m of the allograft group indicates a disturbance in the mitochondrial respiratory pathway during acute rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Valve extension with glutaraldehyde-preserved autologous pericardium. Results in mitral valve repair.

Preliminary experimental studies in our laboratory have shown that autologous pericardium treated with glutaraldehyde prevents late deterioration and calcification of the tissue. For this reason, glutaraldehyde-treated autologous pericardium has been used in a series of 64 patients who underwent operations for leaflet extension of the mitral valve between 1980 and 1989. Ages ranged from 2.5 to 60 years (mean 19 +/- 15). The causes of mitral valve insufficiency were rheumatic fever (69%), bacterial endocarditis (17%), congenital (8%), endomyocardial fibrosis (4.5%), and trauma (1.5%). The autologous tissue was fixed in a 0.62% glutaraldehyde solution for 15 minutes and rinsed in saline for an additional 15 minutes. Patching techniques varied depending on the site and the extent of the lesion. Associated mitral valve repair techniques (Carpentier's techniques) were mandatory in all patients. The period of follow-up extended from 6 months to 9 years (mean 3.1 +/- 2.5 years). There were no operative deaths in this series, and there was one late death (2%). In the six patients (12%) who underwent reoperation, there has been no case of calcification of the pericardial patch. Postoperative mitral valve function was assessed by bidimensional color Doppler echocardiographic techniques. Mitral valve insufficiency was trivial or absent in 80% of the patients. This experience permits us to conclude that leaflet extension is a simple and safe technique in valve reconstruction, allowing repair of mitral valves that otherwise would need to be replaced. It permits use of an adult-size prosthetic ring in children. Glutaraldehyde-treated autologous pericardium is the material of choice for this type of repair.

Adolescent↗
PubMed1991

[Postoperative iatrogenic coronary-ventricular fistula].

Acquired coronary cardiac fistulas are rare. To date, thirty cases have been published in the literature, all secondary to thoracic trauma. The right cardiac chambers were more frequently involved. A recent continuous cardiac murmur is the most constant finding. Nontreated, these lesions tend to induce coronary insufficiency and congestive heart failure. 22 of the 30 reported cases were managed surgically. We hereby report a case of postoperative coronary cardiac fistula secondary to left ventricular venting, in which the fistula involved the left ventricular cavity.

Coronary Vessels↗
PubMed1991

Temporary mechanical circulatory support for severe cardiac failure: experimental study.

We describe a technique for mechanical cardiac assistance in an acute model of severe cardiac failure. Cardiac dysfunction was induced by a high dose of halothane in 13 dogs. Seven served as controls. Following median sternotomy, a pneumatically driven device was implanted in the other six dogs in a para-aortic position, using a simple surgical technique without cardiopulmonary bypass. The aorta was cross-clamped during cardiac assistance. During hemodynamic studies, the seven control animals with induced cardiac failure showed high end-diastolic left ventricular and right atrial pressures with low cardiac index and systolic left ventricular and aortic pressures. All dogs in this group died within 30 minutes. Use of a monovalvular cardiac assist device in the experimental group of six dogs to pump blood from the aortic root to the descending aorta in a counterpulsation manner, confirmed good preservation of systemic hemodynamic parameters after induction of heart failure. All animals in this treated group survived more than 45 minutes. Hemodynamically, the device acts as a new ventricle and the impaired left ventricle functionally becomes a left atrium. This condition is clinically appropriate for recovery of left ventricular function in severe acute myocardial failure.

Animals↗
PubMed1991

Failures in reconstructive mitral valve surgery.

From 1969 to 1985, mitral valve repairs using Carpentier's technique were performed for acquired mitral valve incompetence. 72 patients required a reoperation 3 days to 13 years later (mean 5 +/- 3.5 years). The reoperation rate risk was dependent upon the etiology: Barlow 0.6 +/- 0.2% patient year, fibro-elastic deficiency 0.7 +/- 0.3, endocarditis 1.7% Rheumatic disease 4.6 +/- 1.4%. The risk of reoperation in Rheumatic disease is significantly higher (p less than 0.05) than in degenerative disease. The causes of failures could be categorized into two groups according to whether they are surgeon related or valve related: Group I, Prosthetic ring dehiscence or malposition 15%, anulus dilatation (when no ring was implanted) 4%, triangular resection of the anterior leaflet 4% residual prolapse 8.3%. Group II, Recurrent prolapse 16.6% valve stenosis 17%, leaflet retraction 35%. Failures in Group I can be reduced with "increased" experience as opposed to group II. At reoperation valve repair was possible in 15.3% of the cases whereas valve replacement was necessary in 84.7% with an overall operative mortality of 1.4%. We conclude that mitral valve repair in acquired mitral incompetence carries out a small risk of reoperation. Most of the repair failures are surgeon related in degenerative disease and valve related in rheumatic disease.

Adolescent↗
PubMed1990

[Combined coronary and lower limb revascularization: a new technique].

The management of patients with concomitant coronary and aorto-iliac atherosclerosis is subject to controversy, but it is universally agreed that coronary artery surgery should precede aorto-iliac reconstruction. The technique described here consists of an ascending aorta to bifemoral graft. It allows combined surgery of the coronary and lower limb arteries to be performed without opening the peritoneum.

Angiography↗
PubMed1990

[Acute ischemia of the legs caused by white clot syndrome after cardiac surgery].

A case of post-surgical heparin-induced thrombocytopenia with bilateral aorto-iliac thrombosis (the so-called "white clot syndrome") is reported. The clinical manifestation was acute ischaemia in both lower limbs, requiring surgery. In view of the patient's poor general condition 15 days after a double aorto-coronary bypass, the surgical treatment was limited to ilio-femoral thrombectomy associated with extra-anatomical bypass. This, combined with medical treatment, resulted in resolution of all thrombotic symptoms and disappearance of the intra-aortic thrombi at control Doppler ultrasonography and arteriography performed one month later.

Aorta, Abdominal↗
PubMed1990

Preliminary report: follow-up after dynamic cardiomyoplasty.

Five patients were studied 5-13 months after dynamic cardiomyoplasty for refractory heart failure. In two, muscle flap stimulation caused a pronounced increase in cardiac index (mean 55%) and ejection fraction (mean 75%); no patient showed improvement in cardiac filling pressure. 2 years after surgery, one of the patients with haemodynamic improvement died from ventricular fibrillation, and histochemistry of the stimulated muscle flap revealed predominantly fatigue-resistant type I fibres, without evidence of fibrosis. In selected cases, dynamic cardiomyopathy could be of long-term benefit.

Adult↗
PubMed1990

Perioperative assessment of the quality of myocardial protection.

Perioperative myocardial protection constitutes one of the major advances of modern cardiac surgery, but perioperative assessment of its quality is difficult in clinical practice. This review details our approach to myocardial protection in specific situations, as well as the techniques we use to assess it in three different settings: Is distribution of antegrade cardioplegia homogeneous in patients presenting coronary artery stenosis? The problem was to determine if cardioplegic solutions used antegradely or retrogradely could represent a reliable echographic contrast for myocardial imaging in coronary artery disease patients and normal coronary artery patients, and further if significant differences of myocardial contrast exist between the two methods. Does warm reperfusion cardioplegia improve postoperative myocardial function in patients with an ejection fraction (EF) less than 35%? Pre- and postoperative hemodynamic workup with construction of Starling curves were used to answer this question. Does reperfusion of ischemic hearts induce free radical formation in humans? Deleterious effects of reperfusion are usually determined by studying the effects of free radicals on the myocardium, by determining the concentrations of substances that reflect the degree of membrane phospholipid destruction. However, the specificity and the sensitivity of such assays are low. We recently described white cell chromosomal aberrations secondary to free radical formation, after ischemic and reperfusion injury. Values obtained are expressed as the percentage of the total number of chromosomes. Although specialized laboratory techniques are required, this test is highly accurate.

Chromosome Aberrations↗
PubMed1990

Valve repair in acute endocarditis.

Forty patients were operated on in the early phase of active endocarditis between 1980 and 1988. Indications for operation were heart failure (30 patients), severe valvular regurgitation (4), uncontrolled sepsis (2), septic emboli (3), and other (1 patient). Time between onset of endocarditis symptoms and operation ranged from 12 to 45 days (mean, 30 days). The aortic valve was involved in 3 patients; the mitral valve, in 28; both valves, in 7; and the tricuspid valve, in 2. There was no previous underlying valve pathology in 40%. Lesions found were cusp perforation (17 patients), annular abscess (4), vegetation (13), and chordal rupture (22). Positive blood cultures were found in 30 patients (75%). Bacterial findings were Streptococcus in 12 patients (30%), Staphylococcus in 15 (37.5%), gram-negative in 3 (7.5%), and unknown in 10 (25%). Criteria to perform valve repair were adequate antibiotic therapy for at least 1 week and large excision of all macroscopically involved tissues. In all cases, Carpentier's reconstructive techniques were used. Perioperative mortality was 2.5% (1 patient). Reoperation was necessary in 1 patient. Late mortality was 2.5% (1 patient). Repair was assessed either by angiography or by Doppler echocardiography before hospital discharge: 32 patients showed no regurgitation, whereas 7 had mild regurgitation (3 aortic, 4 mitral). Mean follow-up of 30 months was achieved in all survivors. There was no recurrence of endocarditis and no reoperation for valvular insufficiency. We conclude that valve repair in acute endocarditis is possible and effective in most instances.

Acute Disease↗
PubMed1990

Use of glue without graft replacement for type A dissections: a new surgical technique.

A new surgical technique for treating type A aortic dissections is described. It consists of the exclusive and extensive use of surgical glue without replacing a segment of the ascending aorta. Since 1984, 21 patients were operated on using this technique. No operative mortality occurred and one reoperation for redissection was required. The technique is simple and safe and yields excellent short-term and long-term results.

Aortic Dissection↗
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↗