PubMed HealthSearch

Biomedical subjects

O Bical

Publications and source records attributed to O Bical.

At least 19 recordsLinked to original sources

[False aneurysm of the left ventricle during the acute phase of myocardial infarction: diagnosis by transesophageal echocardiography].

The authors report a case of myocardial infarction complicated by a false aneurysm of the posterior wall of the left ventricle, the diagnosis of which was confirmed, for the first time, by transesophageal echocardiography (TEE) which provided better definition of the anatomical features of the lesion: visualisation of the particularly wide neck (5 cm) and the site of rupture of the myocardium; demonstration of the presence in the false aneurysm with a thin pericardial wall of a large thrombus of different acoustic density, itself overlain by swirling whorls. Colour Doppler combined with TEE clearly showed the acceleration of flow at the neck and its slowing in the newly formed cavity. Once the diagnosis was made, the patient rapidly underwent surgery with a successful outcome. The quality of the images obtained without risk by TEE suggests the important role which this investigation could play in the future in the diagnosis of certain mechanical complications of myocardial infarction.

Diagnosis, Differential

[Decrease of postoperative morbidity in coronary surgery using the two internal mammary arteries].

The surgical risk of bilateral internal mammary artery grafting was analyzed in 100 successive patients separated chronologically into two groups. These groups were not statistically different in terms of age, severity of angina, and extent of coronary artery disease. The number of grafts per patient and the time of aortic cross clamping were not statistically different in the two groups. The postoperative mortality was 1% in the 100 patients. The incidence of perioperative myocardial infarction was not statistically different in the two groups. No mediastinal suppuration was observed. The mean postoperative hemorrhage was 633 +/- 558 ml in the first 50 patients and 560 +/- 410 ml for the last 50 patients (p < 0.05). The percentage of patients receiving no homologous blood transfusion was 64% in the first 50 patients and 94% in the last 50 patients. The percentage of phrenic palsy was 36% in the first 50 patients and 6% in the last 50 patients (p < 0.05). With surgical experience, the risk of coronary bypass with bilateral internal mammary artery was lowered and very similar to the surgical risk of conventional aorto-coronary bypass with saphenous veins or one mammary artery.

Adult

[Tetralogy of Fallot and mitral valve stenosis].

The association of tetralogy of Fallot and mitral stenosis is extremely rare. This is probably the first description of this association. The clinical and haemodynamic presentation is similar to that of cyanotic heart disease with pulmonary stenosis and post-capillary pulmonary hypertension. The mitral stenosis was probably congenital as it was diagnosed at 14 months of age.

Adult

[Coronary artery bypass with 2 internal mammary arteries. Early clinical and angiographic results in 100 patients].

One hundred patients underwent coronary revascularisation with both internal mammary arteries between 1987 and 1990. The average age of the patients was 55 years. The left internal mammary was used in 97 of the 100 cases as a pediculated graft to revascularise the left anterior descending (66 cases), left lateral (27 cases) or a bissecting artery (4 cases). The right internal mammary was used as a pediculated graft in 51 cases and as a free graft to revascularise a left lateral (51 cases), left anterior descending (29 cases) or right coronary artery (20 cases). There was one death in the first 30 postoperative days. Morbidity was low with no cases of sternal infection. The average postoperative bleeding was 633 +/- 550 ml per patient. The incidence of phrenic nerve paralysis decreased from 36% in the first 50 patients to 6% in the second 50 patients. Angiography at the 10th postoperative day showed 4 occlusions out of 132 internal mammary arteries opacified (97% patency). Ninety four patients are asymptomatic and have negative exercise stress tests. Mortality and morbidity of coronary surgery using the two internal mammary arteries are therefore the same as those of conventional coronary surgery using saphenous veinar only one internal mammary artery, providing that it is reserved for patients in good general condition, under 65 years of age, without obesity or diabetes. This technique of coronary artery revascularization should provide better long-term results because of the high patency rate of the grafts.

Adult

Comparison of different types of cardioplegia and reperfusion on myocardial metabolism and free radical activity.

Current techniques of myocardial protection during global ischemia include hypothermia, cardioplegic arrest and controlled reperfusion. To compare different types of cardioplegia and reperfusion techniques we measured the levels of adenine nucleotides and malondialdehyde (MDA, as free radical activity) in 33 patients undergoing heart surgery. The patients were randomized in three groups according to the characteristics of cardioplegia and reperfusion: cold blood cardioplegia with unmodified blood reperfusion (control group, 11 patients), crystalloid cardioplegia and reperfusion (Hôpital Lariboisière protocol, 11 patients) and crystalloid cardioplegia with allopurinol enriched blood reperfusion (Hôpital Broussais protocol, 11 patients). Myocardial biopsy specimens were obtained before cardioplegic arrest (preischemic values), at the end of ischemia and after 30 minutes of reperfusion. Biopsy specimens were analyzed by high performance liquid chromatography for levels of adenine nucleotides and MDA. In the three groups, the preischemic values of adenine nucleotides and MDA were not significantly different. For AMP and ADP concentrations neither treatment nor biopsy-time effects appeared. ATP concentration decreased significantly with biopsy-time without specific treatment effect. For MDA concentration neither treatment nor biopsy-time effects were observed. This study suggests that there is no statistically significant difference between any of the three cardioplegia and reperfusion techniques for either ATP or MDA; the three reperfusion techniques limit the free radical activity but do not prevent the fall in high energy phosphates.

Adenine Nucleotides

[Value of coronary reperfusion in cases of very low cardiac output following coronary artery bypass grafts].

From January 1986 to December 1988, 244 patients had a coronary artery revascularization at St Joseph Hospital. Four patients (1.8%) died in post operative time (less than 30 days). None died directly from cardiogenic shock. Five patients had a severe low cardiac output (2 h to 48 h post-op) and needed cardiac resuscitation. These patients were immediately taken to the operating room. The coronary bypasses were explored (2 technical errors corrected), the metabolic disorders were treated and a coronary reperfusion was done with the Buckberg's technique. All the patients could be weaned from cardiopulmonary bypass, two with intra aortic balloon pumping. One patient died of digestive complication the 10th postoperative day. The four other patients survived and are in good clinical condition. The severe low cardiac output after coronary revascularization can be reversible with resuscitation in operating room, short assistance, and coronary reperfusion.

Aged

[Improvement in the prognosis of severe mediastinitis by the use of muscle flaps].

Between 1984 and 1988, 12 mediastinitis were observed in a series of 1.724 cases of cardiac surgical procedures by sternotomy (0.7%). These 12 patients were retrospectively separated in 2 groups in terms of surgical management. In group I (5 patients in 1984 and 1985) the treatment was mediastinal irrigation and in case of failure, an omental transposition. In group II (7 patients in 1986, 86 and 88) the treatment was mediastinal irrigation and in case of failure, a mobilization of muscle flaps. Four patients died in group I of poly-visceral failure with a persistent severe sepsis. In group II, there was no death and the cicatrization was quickly obtained with an average length of stay in intensive care unit of 62 days. The mediastinal irrigation is the treatment of choice for benign mediastinitis, but the prognosis of severe mediastinitis was in our series greatly improved by muscle flap procedures realized with plastic and reconstructive surgical techniques.

Cardiac Surgical Procedures

[Results of the surgical treatment of tetralogy of Fallot before 6 months of age. A consecutive series of 62 cases with 49 complete repairs].

From January 1980 to July 1988, 62 infants aged under 6 months with an uncomplicated Tetralogy of Fallot (single ventricular septal defect, normal coronary arteries, no localised pulmonary artery branch stenosis) underwent 64 surgical procedures. The indications for surgery were increasing cyanosis and/or anoxic spells. Fourteen systemic-pulmonary shunts (21.5%), 49 complete repairs (75.4%) and one enlargement of the right ventricular outflow tract and of the main pulmonary artery without closure of the ventricular septal defect, were performed. The results of palliative shunts are preoccupying: cumulative mortality of 36 per cent; high rate of early reoperation for complete repair: 14 per cent. Complete repair was associated with an operative mortality of 14 per cent. Only one child had to be reoperated. There was no late death after complete repair compared with 2 late deaths after shunt. Ultimate results of complete repairs are good. Some risk factors were statistically significantly associated with complete repair: age (2.5 months or less), weight (4,500 g or less), measurements of the pulmonary arteries estimated by the diameter of the right pulmonary artery (5 mm or less). Conversely there was no death in the subgroup of 31 infants aged more than 2.5 months without major pulmonary hypoplasia (diameter of the right pulmonary artery over 3.5 mm). One-stage complete repair give the best short and medium-term surgical results in treatment of uncomplicated Tetralogy of Fallot in infants, irrespective of age and weight providing they have no diminutive pulmonary arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors

[Evaluation of 90 normal aortic valve prosthesis of the Saint-Jude Medical type by echocardiography].

Between September 1986 and February 1989, ninety patients undergoing isolated aortic valve replacement were studied on the 15th postoperative day, in the Department of Cardiac Surgery at St Joseph's Hospital, Paris. Patients with a diastolic murmur, fever, significant, pericordial effusions and poor quality Doppler recordings were excluded. The aim of the study was to determine normal Doppler echocardiographic parameters of St Jude medical aortic valve prostheses. Maximum and mean transprosthetic pressure gradients were calculated by the simplified Bernoulli equation. Functional value surface area was assessed by the continuity equation using the diameter of the left ventricular output tract measured by 2D echocardiography (continuity) and the external diameter of the prostheses (modified surface area) to calculate the subaortic surface area. The transprosthetic pressure gradients G max and G mean were inversely correlated to the size of the prostheses (r = 0.42 and r = 0.45). The functional valve surface area calculated by the continuity method gave a poor correlation but this improved considerably when the diameter of the prosthesis (modified surface area) was considered. Finally, the permeability index which is the ratio of subaortic and transaortic velocities seemed to be a good parameter for assessing prosthetic valve function.

Adolescent

Intrauterine versus postnatal repair of created pulmonary artery stenosis in the lamb. Morphologic comparison.

Experimental lamb models were used for intrauterine creation of pulmonary artery stenosis and later intrauterine repair or postnatal repair. Intrauterine creation of pulmonary artery stenosis was performed in 23 fetal lambs at 90 +/- 1 days of gestation. Eight lambs underwent intrauterine repair of pulmonary artery stenosis at 135 +/- 1 days of gestation and were studied 110 +/- 13 days after repair. Seven lambs underwent postnatal repair at 57 +/- 9 days after birth and were studied 162 +/- 32 days after repair. Eight fetal lambs with unrepaired pulmonary artery stenosis were studied 89 +/- 18 days after birth. All study lambs were compared with normal control lambs. The systolic right ventricular pressure was significantly higher after unrepaired stenosis (78.6 +/- 6.8 mm Hg) than in other lambs, but there was no statistically significant difference after intrauterine repair (23.3 +/- 2.9 mm Hg), postnatal repair (25.9 +/- 3.4 mm Hg), and normal lambs (21.6 +/- 1.1 mm Hg). The systolic pulmonary artery pressure was also not statistically different in these three groups. The weight measurements were age-adjusted for comparison of postnatal and intrauterine repair with normal lambs. The adjusted heart weights were similar in the three groups. The comparison of the adjusted heart weight/adjusted body weight ratio (10(-3) showed a significantly higher ratio in postnatal repair (7.4 +/- 0.1) than in intrauterine repair (6.1 +/- 0.1). The adjusted right ventricular weight/adjusted left ventricular weight ratio was significantly higher in the postnatal repair group (0.71 +/- 0.01) than in both the intrauterine repair group (0.59 +/- 0.01) and normal lambs (0.59 +/- 0.01). The transverse myocyte diameter was not statistically different in all groups of animals and there were no ultrastructural changes even when the pulmonary stenosis was unrepaired. We conclude that intrauterine repair was more satisfactory than postnatal repair in terms of age-adjusted heart weight results, but we did not find any advantages of intrauterine repair in terms of histologic and ultrastructural changes.

Animals

[Peroperative autologous transfusion in cardiac surgery. Course, medical and economic evaluation. Prospects].

The authors report their experience since 1979 in the utilization of a system for blood salvaging in cardiac surgery. An initial comparative study showed that the patient group in which blood salvaging was used, received only 0.8 unit of red cells per patient and per hospitalisation and 50% of patients required no transfusion. In the patients receiving ATS, postoperative bleeding was significantly decreased. To confirm the advantages of the technique, a group of 200 patients was studied, consisting of 28 children and 172 adults. Hemodilution was difficult to perform in children weighing less than 15 kg. Nevertheless, ATS allowed for a significant reduction in the number of red cell units transfused. In the adult group, homologous blood consumption was 0.3 unit per patient and per hospitalization. 83% of the patients received no red cells, and 93% had no need for FFP. This reduction in homologous blood transfusion ensures a reduction in the transfusional risk. An improvement in these results will be obtained by a better organization of preoperative ATS and of the retrieval of postoperative blood.

Adolescent

Intrauterine creation and repair of pulmonary artery stenosis in the fetal lamb. Weight and ultrastructural changes of the ventricles.

Fetal lamb experimental models were employed for intrauterine creation and repair of pulmonary artery stenosis. The study group was composed of 51 fetal lambs including 29 models of pulmonary artery stenosis and 22 control lambs. Gestational age was 89 days at creation of pulmonary artery stenosis. Fourteen fetal lambs (Group A) were studied after creation of the stenosis at 131 days of gestation and compared to normal age-matched control lambs. The systolic right ventricular pressure was significantly higher after creation of pulmonary artery stenosis (76.6 +/- 17.8 versus 50.3 +/- 23.5 mm Hg), but the systolic pulmonary artery pressure was unchanged. The mean right ventricular weight and the mean right ventricular/left ventricular weight ratio were significantly greater after pulmonary artery stenosis than in normal control animals. The transverse myocyte diameter was not modified by pulmonary artery stenosis, but on electron microscopic study the myocytes appeared mature. Ten lambs (Group B) underwent intrauterine repair of pulmonary artery stenosis at 131 days of gestation without cardiopulmonary bypass. The pulmonary artery was clamped and patched. Immediately after repair the right ventricular pressure fell significantly from 85.8 +/- 18.9 to 62.2 +/- 14.6 mm Hg. At birth, 7 +/- 6 days after repair, Group B was compared to Group C (unrepaired pulmonary artery stenosis, five fetuses) and to normal control lambs. The mean right ventricular weight and the mean right ventricular/left ventricular weight ratio were not statistically different in Group B and in the control group. There were no ultrastructural changes after intrauterine repair. We conclude that intrauterine creation of pulmonary artery stenosis causes right ventricular hypertrophy with more mature myocytes. Intrauterine repair of pulmonary artery stenosis is feasible without cardiopulmonary bypass and rapidly abolishes the preponderance of right ventricular weight over left ventricular weight.

Animals

[Isolated coarctations of the aorta. Early repair by aortoplasty with the left subclavian artery. 15 cases].

When medical treatment is ineffective, isolated aortic coarctation must sometimes be surgically repaired during the first months of life. For these early operations the Crafoord resection-anastomosis technique seems to be disappointing, with a high recurrence rate. Between 1979 and 1983, 15 infants under 6 months of age underwent repair of their coarctation by a different technique: longitudinal aortoplasty using the left subclavian artery. One child died of septic rupture of the aorta, and another was lost sight of. The remaining patients were examined 35 +/- 15 months after surgery. The blood pressure usually returned to normal with no pressure gradient, at rest, between the right upper limb and the lower limbs. One child, however, had a slight (10 mm Hg) residual gradient corresponding to discreet alterations at two-dimensional echocardiography. These good results at rest after aortoplasty seem to be better in medium term than those of resection-anastomosis. The left subclavian flap aortoplasty appears to be the technique of choice in children under 6 months for the treatment of isolated coarctation.

Aortic Coarctation

Experimental evaluation of porcine-valved conduits processed with a calcium-retarding agent (T6).

The effectiveness of a water-soluble C-12 alkyl sulfate (T6) (U.S. Patent No. 4,323,358) in retarding bioprosthetic calcification was evaluated in 23 porcine-valved conduits (13 T6-treated conduits and 10 controls) implanted in young sheep between the right ventricle and the pulmonary trunk. The grafts were divided into three groups according to the period of function: Group I, less than 2 months; Group II, 2 to 4 months; and Group III, 5 to 7 months. In Group I (four T6 and four controls), endocarditis occurred in five cases. In Group II (three T6 and three controls), four conduits showed severe fibrous peel ingrowth. In Group III (six T6 and three controls), fibrous peel was the main feature in four conduits and calcium deposits occurred in the porcine aortic wall in all cases, with cusp involvement in two; in both T6-treated and control conduits, chemical analysis showed a much lower calcium content of the cusps (8.45 +/- 80 versus 2.95 +/- 1.52 mg/gm dry weight, respectively) than that reported in other animal or human explants. The grade of calcification in control and T6-treated conduits was equal on x-ray analysis, and no differences in calcification patterns were noted on electron microscopy. This experimental model shows a low degree of cusp calcification and no significant differences between T6-treated and control conduits. Peel formation markedly interferes with performance of the porcine-valved conduit. The results of this analysis indicate that valved conduits are not the optimum model for evaluating calcium-retardant agents in biological valves.

Animals

End-systolic left ventricular pressure-dimension shift during acute relief of volume overload in the conscious dog.

To test whether left ventricular (LV) end-systolic dimensions are determined only by end-systolic pressure for a given inotropic state, 7 conscious dogs were studied during abrupt closure of a fistula created between the left subclavian artery and the left atrial appendage. The dogs were instrumented with an LV pressure micromanometer and ultrasonic crystals measuring LV major- and minor-axis diameters and ventricular wall thickness. During beta-blockade treatment and for the same end-systolic pressure, closure of the fistula produced a 40% decrease in cardiac output; end-diastolic diameter decreased by 1.5 mm and end-systolic diameter decreased by 0.9 mm. Calculated end-systolic volume was similarly decreased by 1.3 ml for a decrease of 2.9 ml of end-diastolic volume. Thus, large end-diastolic dimensional variations associated with peripheral resistance decrease significantly modify the end-systolic pressure-diameter (and volume) relations in the conscious animal. It is suggested that indexes obtained from these relations should not be used in patients when systolic pressure variations are associated with large stroke volume variations.

Adrenergic beta-Antagonists

[Antenatal cardiac surgery. Creation of an experimental model of pulmonary stenosis in the fetus and repair in utero].

An experimental model of pulmonary stenosis was created in ewes, fetus and repaired before birth by making use of the materno-foetal circulation. Eighteen ewes fetus underwent pulmonary artery banding at an average of 87 +/- 8 days' gestation (normal 135-145 days). All were reoperated before term at 132 +/- 6 days' gestation. They were divided into two groups : group I (7 fetus) was used to evaluate the experimental model of pulmonary stenosis by measuring right ventricular pressures (80 +/- 16 mmHg compared to 58 +/- 10 mmHg in control models), and the increase in right ventricular mass (2.8 +/- 0.5 X 10(-3) g vs 1.9 +/- 0.2 X 10(-3) g), left ventricular mass (2.2 +/- 0.3 X 10(-3) g vs 1.8 +/- 0.4 X 10(-3) g) and septal mass (1.8 +/- 0.3 X 10(-3) g vs 1.3 +/- 0.2 X 10(-3) g). In group II (11 fetus) the pulmonary stenosis was repaired by total clamping and patch repair. After repair and during the days just before birth, the ventricular masses decreased (RV = 2 +/- 0.3 X 10(-3) g; LV = 1.8 +/- 0.4 X 10(-3) g; septum = 1.8 +/- 0.3 X 10(-3) g) approaching values of normal control fetus. This experimental model shows that it is possible to correct cardiac lesions in utero by making use of the materno-fetal circulation and that antenatal repair of an arterial obstruction can rapidly reverse the reactional ventricular hypertrophy.

Animals