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Biomedical subjects

A Carpentier

Publications and source records attributed to A Carpentier.

At least 289 records · Page 16Linked to original sources
PubMed1986

Partial reversal of low molecular weight heparin (PK 10169) anti-Xa activity by protamine sulfate: in vitro and in vivo study during cardiac surgery with extracorporeal circulation.

Neutralization of a low molecular weight (LMW) heparin fraction by protamine sulfate was evaluated in vitro and in vivo. Anti-Xa and anti-IIa activities were measured by amidolytic and coagulation methods (activated partial thromboplastin time, APTT). Fifteen patients (4 males and 11 females) underwent surgery with extracorporeal circulation. In vitro, anti-Xa and anti-IIa activities and APTT of unfractionated heparin were neutralized with a protamine/heparin (P/H) gravimetric ratio of 1.6, 1.33 and about 2, respectively. Anti-IIa activity and APTT induced by PK 10169 were completely corrected at a P/H ratio of 1 and 2, respectively, while anti-Xa activity was incompletely neutralized at a ratio of 5. In vivo, in 9 patients who did not receive intravenous protamine sulfate, a good correlation was found between doses of PK 10169 infused, anti-IIa plasma level and blood loss. In 3 patients who were treated prophylactically with protamine, bleeding was normal or only slightly increased. In 3 patients who received protamine because of hemorrhage, mean anti-Xa and anti-IIa were 2.3 and 0.54 U before and 1.32-0.06 U after neutralization. Bleeding was stopped by a second dose of protamine in 1 patient, but blood loss was abnormal in the other patients. However, a correlation between bleeding and anti-Xa or anti-IIa activities was not clearly evident.

Adolescent↗
PubMed1986

Coronary artery restenosis following transluminal coronary angioplasty.

Morphological changes are described in a case of coronary restenosis occurring three and ten months after transluminal coronary angioplasty. The lesions consisted of severe narrowing of the previously mechanically dilated coronary segments. This narrowing was produced by fibrocellular intimal hyperplasia associated with rupture of the media whereas the atheromatous plaque was not involved. This suggests that medial injury associated with healing intimal hyperplasia could be the major factor resulting in late coronary restenosis.

Angioplasty, Balloon↗
PubMed1986

[Compressive hemopericardium of the right atrium after cardiac surgery].

Between June 1983 and September 1984, 3 patients operated for mitral valve disease presented with acute right heart failure due to right atrial compression. Emergency echocardiography did not show pericardial separation around the ventricles but in the apical 4 chamber view severe right atrial compression by an extracardiac mass was observed. Emergency surgery was performed in all three cases to evacuate a localised haemopericardium despite the absence of pericardial fusion. These cases of acute right ventricular failure underline the importance of multiplying the number of echocardiographic views in order to detect localised pericardial effusion. The diagnosis should be made as soon as possible as clinical deterioration may be rapid despite effusions of small volume. The main differential diagnoses are right atrial thrombosis and acute postoperative pulmonary embolism. In these cases of localised tamponade, the clinical signs are the result of vena caval compression or extrinsic compression of the tricuspid orifice. The preferential localisation of the haemopericardium around the right atrium is difficult to explain. It is probably related to the low pressures in this region. The echocardiographic appearances of this condition have been established allowing reliable diagnosis.

Adolescent↗
PubMed1986

[Sequential internal mammary artery bypass for multiple coronary stenoses].

Long-term studies (10 years) show a 50 per cent patency rate of saphenous vein autograft and 95 per cent patency rate of internal mammary artery coronary bypass grafts. In some situations (after saphenous vein stripping, varicose and fibrotic veins) it is not possible to use venous grafts and the internal mammary artery has to be used. However, the internal mammary artery is usually only used for revascularisation of the left anterior descending artery. Sequential internal mammary artery bypass is a technique which can be used for revascularizing the left anterior descending artery. Seven men aged 44 to 68 years (average 55 years) were operated between November 1983 and February 1985. These patients had clinically stable (4 cases) or instable (3 cases) angina. Two patients had previously undergone bilateral saphenous vein stripping and one patient a terminal anastomosis on the left anterior descending and a latero-lateral anastomosis on the diagonal artery. Three patients had an associated venous bypass graft and one patient also underwent aortic valve replacement. There were no cases of postoperative myocardial infarction. Five control angiographies were carried out during the first postoperative month. In 4 patients the internal mammary graft ant the latero-lateral and termino-lateral anastomoses were patent. In the other case, the latero-lateral anastomosis and the diagonal artery was occluded but the internal mammary graft and the termino-lateral anastomosis on the left anterior descending artery were patent. The average follow-up period is now 18 months: there have been no recurrences of chest pain or any ECG changes. These results show that internal mammary artery bypass grafting is a delicate procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Low molecular weight heparin in extracorporeal circulation. 1st clinical applications].

The haemorrhagic complications inherent to the use of heparin during cardiac surgery led us, after a pilot experimental study, to try out a low molecular weight heparin (LMWH), PK 10169, which has weaker haemorrhagic effects in vitro. Our initial experience was confined to 23 patients with differing pathologies, undergoing cardiopulmonary bypass lasting 30 to 165 minutes. The modes of injection of YK 10169 varied according to the results, especially with respect to the limitation of peaks of anti-Xa activity; 8 patients were given one bolus intravenous injection, 9 were given a bolus injection and a continuous infusion, and 6 were only given the continuous infusion. Biological monitoring of anticoagulation was based on anti-Xa activity. Analysis of the biological results showed that the principal feature was the partial correction, and occasionally the non-correction of anti-Xa activity by protamine sulphate, with no correlation between this anti-Xa activity and postoperative bleeding. The authors report cases of severe postoperative bleeding despite the supposed theoretical and experimental weakly haemorrhagic properties of LMWH, and also discuss the inefficacy of protamine sulphate. The indications for LMWH for cardiopulmonary bypass which were retained, were the rare cases of heparin-induced thrombocytopaenia. In conclusion, it is possible to use LMWH during cardiac surgery but we do not advise using it routinely as its theoretical advantages are not confirmed in practice.

Adolescent↗
PubMed1986

Long-term results of valve repair in children with acquired mitral valve incompetence.

From March 1969 to March 1984, 89 children aged 2 to 12 years (mean 8.3 +/- 2.5) with acquired mitral valve incompetence underwent mitral repair using Carpentier's techniques. There were 84 cases of rheumatic valve disease, four cases of endocarditis, and one case of Barlow's syndrome. Valve dysfunction was classified into three types: type I (normal leaflet motion), five patients; type II (prolapsed leaflet), 74 patients; and type III (restricted leaflet motion), 10 patients. Cumulative follow-up was 546 patient/years. At 10 years, 90% of the patients were still alive, with an incidence of valve-related death of 5.5%; 98% of the patients were free of thromboembolism, 78% were free of reoperation, and 69% of the patients were free of any complications related to valve repair. We conclude that whenever feasible (92% of the cases in our experience), mitral valve repair using valvuloplasty techniques is the preferred procedure in the surgical treatment of acquired mitral valve incompetence in children.

Child↗
PubMed1985

Reversibility of muscular ischemia: a histochemical quantification by the nitroblue tetrazolium (NBT) test.

The degree of muscular ischemia and its reversibility can be quantified in the early stages. This histochemical enzymatic study utilized Nitroblue tetrazolium (NBT) which when reduced by tissue dehydrogenase produces a blue pigment: "formazan." Seventy Wistar rats were subjected to transient hindlimb ischemia by means of a tourniquet for 3, 6, 9, 12, 15 and 18 hours, followed by reperfusion. Microsurgical muscle biopsies were obtained in each rat at 1 and 12 hours, and 3, 7, 14 days after reperfusion. Time increased in muscle staining demonstrated a succino-dehydrogenase deficit confirmed by clinical and histopathological follow-up. NBT staining time was 2 minutes (+/- 8 sec.) in the control group, between 2 and 6 minutes in the reversible ischemia group (rats with 3 and 6 hours of tourniquet), and more than 9 minutes (+/- 14 sec.) in the irreversible ischemia group (animals with more than 9 hours of tourniquet). In vascular surgery and in limb reimplantation this protocol is a practical method of evaluating cytoplasmic enzymatic activity and the status of myofibrillar oxidation in the early phases of ischemic injury, before histologic changes are clearly delineated.

Animals↗
PubMed1985

[Prevertebral lesions of the subclavian artery: long-term results of reconstructive surgery and percutaneous angioplasty].

Short and long-term results were compared after reconstructive surgery and percutaneous transluminal angioplasty (PTA) of aortic arch trunks and subclavian arteries in 2 groups of patients (10 after dilatation and 12 after surgery). The technique used for treatment was selected as a function of distribution of lesions, their number and their appearance. Gruntzig's method was applied for PTA, while surgery consisted of either reimplantation of subclavian arteries into the main carotid artery or prosthetic by-pass procedures. Immediate and long-term (mean: 14 months) review examinations were by Doppler velocimetry and digital subtraction angiography. Thromboembolic complications secondary to PTA were not observed and there were no cases of recurrence of stenosis in the 10 patients after follow up for 13 months. Complications after surgery were one case of recurrence of stenosis requiring a repeat operation after 20 months, one case of thrombosis of carotid-axillary shunt after 19 months and one case of repeat surgery for lymphorrhea. Long-term results were very good in this series of 12 patients. It is difficult to compare results of the two techniques, patients treated by surgery having multiple lesions requiring combined procedures, and the number of cases treated being too low. However, PTA appears to be effective therapy for localized, non-ulcerated stenosis, and surgery for long or ulcerated stenosis, complete thrombosis and multiple lesions of aortic arch trunks justifying associated procedures.

Adult↗
PubMed1985

Deleterious effects of cardiopulmonary bypass. A prospective study of bubble versus membrane oxygenation.

A number of hematologic and immunologic parameters that reflect erythrocyte and platelet damage and host defense mechanisms against infection were studied in 20 patients undergoing cardiopulmonary bypass during coronary operations. The patients were randomly assigned to a group in which a bubble oxygenator or a hollow-fiber membrane oxygenator was used. Hemolysis, thrombocytopenia, and significant release of beta thromboglobulin occurred in patients from the bubble oxygenator group and, to much lesser extent, in patients from the membrane oxygenator group. Polymorphonuclear leukocytes and monocytes from bubble oxygenator patients demonstrated increased generation of reactive oxygen species in the resting state and in the presence of the stimulating agents N-formyl-methionyl-leucyl-phenylalanine, concanavalin A, and opsonized zymosan, as compared with cells from membrane oxygenator patients. No difference was found between bubble and membrane oxygenator patients in the time of occurrence or intensity of leukopenia during bypass, of leukocytosis at the end of bypass, nor in the rate of complement activation, as assessed by quantitation of plasma C3a antigen. Complement activation was dependent on the alternative pathway. Immunoglobulin M concentration significantly decreased during bypass in both groups of patients. The serum opsonizing capacity for endotoxin and serum bactericidal activity for Serratia marcescens were decreased in both groups, mainly because of hemodilution, although they were additionally affected by bubble oxygenation. Several deleterious hematologic consequences of cardiopulmonary bypass can be minimized by the use of a membrane oxygenator. However, complement activation remains a potential risk factor even in membrane oxygenator patients and requires further investigation to obtain better hemocompatible materials for cardiopulmonary bypass circuits.

Blood Bactericidal Activity↗
PubMed1985

[Reoperation after saphenous aortocoronary bypass].

The results of a consecutive series of 24 patients reoperated for coronary bypass grafting between May 1977 and February 1983 are reported. The overall incidence of reoperation was 1.4 p. 100 (24 out of 1 716 cases); the incidence is tending to increase (2.3 p. 100 in 1982). Preoperative assessment revealed the persistence of cardiovascular risk factors: 75 p. 100 of patients had continued to smoke; 61 p. 100 had persistent hyperlipidaemia. The usual presenting syndrome was recurrence of chest pain (21 out of 24 cases) leading to control coronary arteriography on the results of which the surgical indication was based. The average time between the two operations was 38.7 months. The patients were classified into two groups; early reoperation (6 cases) for a technical problem or incomplete revascularisation, and late reoperation (8 cases) for disease of the graft and atherosclerosis. Progression of coronary atherosclerosis was the major long-term cause of occlusion of the saphenous graft (10-14 cases). The arteries most commonly bypassed at reoperation were the left anterior descending and right coronary arteries (12 times each). Reoperation comprised single bypass (13 cases), double bypass (10 cases) and triple bypass (1 case) with an average of 1.5 grafts per patient. The most commonly used vein was the internal saphenous vein (32 out of 36 grafts). Myocardial protection was insured by cardioplegia (13 cases) and intermittent clamping (10 cases) after cooling (general hypothermia at 22 degrees C). Global reoperative mortality (4 p. 100) was higher than for elective primary coronary surgery (2.3 p. 100). The incidence of perioperative infarction was 8 p. 100.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMed1985

[Direct atriopulmonary anastomosis (modified Fontan) for single ventricle and its equivalents].

The modified Fontan procedure is being used in an increasing number of complex cyanotic cardiac lesions with pulmonary stenosis. Seven patients aged 11 to 24 years (average 17.5 years) underwent surgery by a technique derived from the Fontan procedure: direct atriopulmonary anastomosis without a tube or valve. The tricuspid valve when patent was closed with a patch. The diagnoses were: single ventricule (4 cases), Taussig-Bing anomaly (2 cases) and tricuspid atresia (1 case). All patients had associated pulmonary stenosis with low pulmonary vascular resistances. The great vessels were in L-malposition in 3 cases. The hospital mortality was nil. Transient atrial fibrillation was observed in 2 cases and was well tolerated clinically. The follow-up period ranges from 2 months to 4 years (average 2.3 years). All patients are acyanotic with no signs of right-sided failure and in sinus rhythm. Control cardiac catheterisation and angiography were performed in 6 cases and showed good function of the anastomosis and a mean atrial pressure of 14 mmHg. Direct atriopulmonary anastomosis offers a very acceptable surgical solution to certain forms of single ventricle or equivalent with low pulmonary pressures. The short and medium term results seem to be better than those of intraventricular repair.

Adolescent↗
PubMed1985

[Transformation of skeletal muscle by progressive sequential stimulation with a view toward its use as a myocardial substitute].

Progressive sequential stimulation of a skeletal muscle using trains of 30 Hz impulses with increasing frequencies from 20/min. to 80/min. within 3 months, allowed us to obtain in goats a transformation of the fast twitch glycolytic muscular fibers into fatigue resistant slow twitch oxidative muscular fibers. The conditioned muscle can be used in the treatment of various myocardial lesions or to reinforce cardiac contractility in severe cardiac insufficiencies. The first clinical case successfully operated upon is reported.

Adult↗
PubMed1984

Low molecular weight (LMW) heparin derivatives in experimental extra-corporeal circulation (ECC).

Low molecular weight (LMW) heparin has been shown to prevent experimental venous thrombosis. In order to investigate its biological action and its potential use in open heart surgery, we have conducted an experimental study using extracorporeal circulation (ECC) in sheep as an experimental model. 18 sheep were randomly selected to receive either LMW heparin (2 mg/kg), high dose heparin (HD; 160 U/kg), or low dose heparin (LD; 60 U/kg). The HD heparin yielded the same circulating anti-activated factor X (anti-Xa) activities as the LMW heparin and the LD heparin yielded the same anti-thrombin activity. LMW heparin and HD heparin were both effective in preventing blood clotting in the ECC circuit, demonstrating the antithrombotic activity of the LMW heparin. Clotting in the circuit was observed following LD heparin administration showing that the efficacy of LMW heparin does not only rely upon its weak anti-activated partial thromboplastin time (APTT) and anti-thrombin activity. Fibrinogen, fibrinogen degradation products (FDP), factor V (FV), platelet count, antithrombin III (AT III), fast acting antiplasmin (AP) were evaluated during and after ECC. The defects in hemostasis were similar in the three groups. Conclusions were: (1) heparin chain depolymerization diminishes the anti-APTT activity without altering the anti-thrombotic property; (2) LMW heparin is an effective alternative to heparin in cardiac surgery; (3) the absence of postoperative circulating anti-APTT activity might be associated with a reduced incidence of hemorrhagic complication, but we were not able to demonstrate it.

Animals↗