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Biomedical subjects

J C Chachques

Publications and source records attributed to J C Chachques.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Cardiomyoplasty. Experimental bases, operative technic, indications].

Dynamic cardiomyoplasty aims at restoring ventricular contractility by means of a skeletal muscle sutured around the heart. It consists of transferring a latissimus dorsi muscle flap onto the heart through a window created in the thoracic wall by partial resection of the second rib. The skeletal muscle may be used to reinforce the ventricular systole in ischemic or dilated cardiomyopathy, or to replace the myocardium after resection of a large aneurysm or an extensive tumour. The electronic pacing material includes an implantable cardiomyostimulator, muscle stimulating electrodes and R wave detecting electrodes. Muscular pacing begins 2 weeks after the operation, this being the time required for adhesions to be formed between the heart and the muscle. A progressive and sequential electrostimulation procedure results in the transformation of glycolytic muscle fibres that are fatigue-sensitive into fatigue-resistant oxidative fibres. The purpose of this biomechanical cardiac assistance system, where cardiac surgery is combined with plastic surgery and biomedical engineering, is to prolong life and improve its quality in patients with severe heart failure.

Assisted Circulation↗
PubMed1989

[Postoperative iatrogenic coronaro-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.

Aortic Valve↗
PubMed1988

Effect of latissimus dorsi dynamic cardiomyoplasty on ventricular function.

In our approach to dynamic cardiomyoplasty, which consists of wrapping a skeletal muscle around the heart and stimulating the former in synchrony with heart contractions to augment ventricular contractility, we have transferred a latissimus dorsi muscle flap to the heart by way of a partial resection of the second rib and subsequently suturing the muscle flap around the ventricles. The muscle flap is stimulated by a Cardio-Myostimulator burst-pulse generator (Medtronic SP 1005) connected to intramuscular electrodes. In preclinical animal research, the latissimus dorsi muscle flap was shown to maintain adequate contractile force and to increase its fatigue resistance by gradual conversion of glycolytic-fatigue-sensitive-to-oxidative-fatigue-resistant muscular fibers (100%). Histochemical and biochemical studies of chronically stimulated muscles showed a total transformation of muscle fast myosin to slow myosin with characteristics similar to those of myocardium. Electron microscopy showed preserved myofibrillar cytoarchitecture and increased mitochondrial density in the cell. At 9 months, cardiac output and ultrasonic Doppler studies showed a significant increase in ventricular function (cardiac output, +21%; peak blood velocity, +40% -80%; and stroke volume, +98% -102%) during muscle stimulation. In the clinical situation, long-term (range of follow-up interval, 4-42 months) beneficial cardiac effects of cardiomyoplasty have been documented in eight patients with various pathologies (ventricular tumor, left ventricular aneurysm, ischemic disease, and dilated cardiomyopathy). Our current understanding of this process is that dynamic cardiomyoplasty acts in two ways: 1) it promotes more vigorous systolic contraction, and 2) it appears to limit heart dilatation.

Animals↗
PubMed1988

Dynamic cardiomyoplasty: a surgical approach for ventricular assistance.

Dynamic cardiomyoplasty involves the use of an electrically stimulated skeletal muscle wrapped around part of the heart to restore or augment myocardial contractility. In our approach, a Latissimus Dorsi muscle flap (LDMF) is transferred to the heart via a partial resection of the second rib, and sutured around the ventricles. The muscle flap is stimulated in synchrony with the heart contractions with bursts of impulses delivered by a "Cardio-Myostimulator" implantable pulse generator via intramuscular electrodes. The object of this study was to identify features of muscle stimulation and to measure the efficacy of L.D. cardiomyoplasty in increasing cardiac output, using an ultrasonic Doppler technique. This report shows the results obtained for goats in which such procedures were performed. Ultrasonic measurements were recorded at the time of cardiomyoplasty and 3-6 months later, during which period the muscle was put progressively into use by slowly increasing the burst frequency content, number of pulses as well as the heart-muscle contraction ratio (3:1, 2:1, 1:1). This postoperative muscle stimulation protocol takes into account the delay of gradual conversion of fast-twitch glycolytic muscular fibers into slow-twitch oxidative, fatigue-resistant fibers, as well as the healing time after cardiomyoplasty required for the muscle flap to recover collateral blood circulation and to adhere to the heart. Results show that synchronous burst stimulation of the muscle flap increases the blood peak velocity in the descending aorta (+36 +/- 8%) and increases the left ventricular stroke volume (+70 +/- 14%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[Histochemical quantification of muscular ischemia: effect of treatment with naftidrofuryl].

Evaluation of degree of muscle ischemia of a limb and its reversibility is a poorly resolved practical problem, and it has not been clarified whether vasodilatory and circulatory spasmolytic substances possess, in addition to an effect of increasing irrigation, any direct action on muscle cell energy metabolism. An experimental study used histochemical techniques to evaluate oxidative enzyme activity of tissues. The compound tetrazolium nitro-blue (NBT), when reduced by tissue dehydrogenases, has the property of producing a dense non-crystalline blue pigment designated "formazan". During muscle ischemia, the time of appearance of this reaction increases with degree of ischemia through the bias of the decrease or disappearance of succinate-dehydrogenases. Transient ischemia of hindpaw, over 3, 6, 9, 12, 15 and 18 hours, was provoked by tourniquet in 49 rats treated with a vasodilator (naftidrofuryl) and 21 untreated (control) rats. Spontaneous revascularization occurred after removal of the tourniquet. Muscles were studied by microsurgical removal of specimens on removal of tourniquet and 1 and 12 hours and 3, 7 and 14 days after its removal (fig. 1 and 2). Times for staining of muscles with tetrazolium were measured and curves of comparative times established (fig. 3 and 4). Histopathologic specimens were also obtained at the same periods (fig. 5, 6, 7). Results of histochemical studies with tetrazolium and with quantitative determination of degree of cellular anoxia showed the action of naftidrofuryl to be related to mitochondrial metabolism of skeletal muscle, specifically for succinate-dehydrogenase. Clinical application in the determination of therapy and of functional prognosis of an ischemic limb is a possibility by the use of the NBT test in vascular surgery.

Animals↗
PubMed1986

Risk and consequence of infection at the site of microsurgical repair: an experimental model.

The consequences of postoperative infection at the site of microsurgical repair were studied. The experiment used 60 Wistar rats which were divided into 3 groups of 20 each. The femoral artery, vein, and nerve were transected unilaterally and repaired using microsurgical techniques. Staphylococcus aureus was then inoculated into the wound of group 1. Beta-hemolytic Streptococcus was inoculated into the wound of group 2. Group 3 rats served as controls. Clinical, anatomical, bacteriological and histopathological examinations were performed on postoperative days 8 and 30. Wounds in which S. aureus was inoculated demonstrated a significant tendency toward vascular thrombosis with extensive tissue destruction. In the majority of these cases, the necrosis caused by the primary infection engendered an associated, opportunistic infection. Streptococcal inoculations in group 2 demonstrated less severe changes than in group 1. These changes were characterized by injury of the vascular structures themselves with a significant tendency for thickening of the arterial wall, perivascular inflammation, and hematoma formation at the site of the repair. This model allows demonstration of the enzymatic and toxic consequences of bacterial infection in a postoperative site characterized by cellular destruction and interstitial edema surrounding foreign bodies represented by sutures.

Animals↗
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↗
PubMed1985

[Acute suppurative myositis. 4 cases].

Four cases of acute pyomyositis are reported. They were diagnosed at an advanced stage, and the different complementary examinations were of uneven value. The responsible pathogen was Staphylococcus aureus in 3 cases and a strain of Streptococcus in 2 cases (one patient had both germs). Cure was obtained in 3 patients, including one who required amputation; the 4th patient died. In this disease only the finding of purulent fluid at surgery or by needle aspiration has a diagnostic value. Management consists of antibiotic therapy associated with surgical drainage.

Acute Disease↗
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

[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↗
PubMed1985

Comparative evaluation of aortic valve replacement with Starr, Björk, and porcine valve prostheses.

Three groups of 100 consecutive patients with aortic valve disease who were operated on between 1974 and 1978 underwent long-term evaluation. There were 100 aortic valve replacements with porcine bioprosthetic valves (group I), 100 with Starr valves (group II), and 100 with Björk valves (group III). There were no significant differences in the preoperative clinical conditions of the patients in the three groups. Cumulative follow-up was 1688 patient-years. Incidence of valve-related death at 8 years was 4 +/- 2.3% in group I, 13 +/- 3.6% in group II, and 13 +/- 3.8% in group III (p less than .05). At 8 years 95 +/- 2.8% of the patients in group I were free of thromboembolism, compared with 81 +/- 4.8% of those in group II and 84 +/- 4.2% of those in group III (p less than .002). The actuarial risk of a reoperation at 8 years was 16 +/- 6% in group I, 5 +/- 2% in group II, and 2 +/- 1.6% in group III (p less than .025 group I vs group III). At 8 years 98 +/- 1.2% of the patients in group I were free of anticoagulant-related complications, compared with 88 +/- 3.8% of those in group II and 86 +/- 3.9% of those in group III (p less than .005). We conclude that at 8 years porcine bioprosthetic valves performed better than mechanical valves, taking into consideration thromboembolism, anticoagulant-related hemorrhage, and valve-related death.

Actuarial Analysis↗
PubMed1984

[Comparative evaluation of various methods of treatment of mitral valve diseases. Apropos of 4 series of 100 patients operated on using the Starr prosthesis, Bjork prosthesis, bioprosthesis and valve reconstruction].

The results of 4 groups of 100 patients undergoing mitral valvuloplasty (group I), isolated mitral valve replacement by a bioprosthesis (group II), a Starr-Edwards prosthesis (group III) and a Björk prosthesis (group IV) between 1974 and 1977 were compared. The selection of patients for each group was identical and made according to strict criteria. The average age was between 47.1 +/- 12.5 years and 51.8 +/- 10.5 years according to the particular group; the average functional classification was 2.4 +/- 0.4 to 2.5 +/- 0.6; the average cardiothoracic ratio was 0.58 +/- 0.07. Most patients were in atrial fibrillation. Ninety-seven per cent of patients were followed-up by questionnaires. The results were expressed with respect to simple clinical events used in all previously reported series. The long-term mortality was identical in the 3 groups undergoing valve replacement (40 p. 100 at 7 years) but was much less in the group undergoing valvuloplasty (18 p. 100 at 7 years). The mortality rate due to valvular problems was significantly less in the valvuloplasty group (2 p. 100 at 7 years) than in the groups with mechanical prostheses (20 p. 100 at 7 years). Intermediate results were observed in the bioprosthetic group (9 p. 100 at 7 years). Thrombo-embolism was significantly less common in the groups undergoing valvuloplasty and bioprosthetic valve replacement (2 p. 100 and 6 p. 100 at 7 years) than in the group with Starr-Edwards and Björk prostheses (30 p. 100 and 32 p. 100 at 7 years).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗