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Biomedical subjects

O Chavanon

Publications and source records attributed to O Chavanon.

45 records · Page 3Linked to original sources
PubMed1998

Exposed prosthesis of a complex reconstruction of the ascending aorta and aortic arch in a sternal wound infection: Successful treatment by a pectoral muscle flap.

A local wound infection developed in a 42-year-old female patient after replacement of ascending aorta, aortic arch and supra-aortic vessels, following aortic dissection. Because of the high risk of infection due to the vascular prosthesis and its location at the upper part of the sternum, a right pectoral muscular flap, detached from the humerus and vascularized by medial perforators originating from the internal mammary artery, was isolated. The postoperative course was uneventful and the patient remains well 16 months after the operation.

Adult↗
PubMed1998

Frusemide inhibits angiotensin II-induced contraction on human vascular smooth muscle.

AIMS: Frusemide is widely used in the treatment of acute pulmonary oedema, chronic congestive heart failure and, to a lesser degree, in the treatment of hypertension. Evidence suggests that frusenuide exerts an anti-vasoconstrictor effect independent of its diuretic properties. Since angiotensin II is a highly potent vasoconstrictor involved in the pathophysiology of these diseases, we have investigated the effect of frusemide on the contraction elicited by angiotensin II on human internal mammary artery (IMA) and saphenous vein (SV). METHODS: Rings of IMA and SV were suspended for isometric tension recording in organ baths. Concentration-response curves to angiotensin II were performed in the absence (control) or in the presence of frusemide (10(-6) to 10(-3) M). In addition, the effect of frusemide was evaluated after cyclooxygenase inhibition by indomethacin (10(-6) M) and was compared with those of the other loop diuretic bumetanide (10(-4) M). RESULTS: Frusemide induced a concentration-dependent decrease of the contraction elicited by angiotensin II on IMA and SV. On both vessels, the inhibitory effect on the maximal contraction to angiotensin II was significant with concentrations of frusemide from 10(-5) to 10(-3) M. Angiotensin II potency (pD2) was only reduced by 10(-3) M frusemide. The effect of frusemide was not altered in the presence of indomethacin. Bumetanide was less potent than frusemide in inhibiting angiotensin II-induced contractions in both IMA and SV. CONCLUSIONS: Frusemide, at concentrations in the therapeutic range (10(-5) M), inhibits angiotensin II-induced contraction on human isolated IMA and SV. This inhibitory effect is cyclooxygenase independent and appears mediated, at least in part, by inhibition of Na+/K+/2Cl- symport. Reduction in the vasoconstrictor effect of angiotensin 1 may be involved in the therapeutic efficacy of frusemide.

Angiotensin II↗
PubMed1997

Computer assisted pericardial puncture: work in progress.

Until now, computer assisted surgery has focused primarily on surgical procedures involving rigid anatomical structures. Because soft tissues can be highly mobile and deformable, they may require specific imaging devices, suitable modeling tools, and guiding systems. Percutaneous pericardial puncture is a good clinical target for computer assisted surgery; this procedure is often performed without direct visualization and is dangerous even though echographic control is used. Computer assistance can greatly improve this technique and will allow accurate puncture of preplanned targets. This paper describes a new approach for computer assisted pericardial punctures (CASPER) and describes a first feasibility analysis of CASPER demonstrated with anesthetized animals. The approach is based on the use of echographic data localized in space, from which an optimal strategy is defined. Because of the specificity of the pericardial effusion, a stable target can be selected despite the heart motions. A passive guiding system is used. We have demonstrated the feasibility of the approach.

Animals↗
PubMed1997

Effect of low-dose positive inotropic drugs on human internal mammary artery flow.

BACKGROUND: Dobutamine (a beta-receptor agonist), enoximone (a type III selective phosphodiesterase inhibitor), and epinephrine (an alpha- and beta-mimetic) frequently are used in the perioperative management of patients undergoing coronary artery bypass grafting. METHODS: We performed a double-blind clinical study to compare the effects on internal mammary artery free flow of low doses of these three positive inotropic drugs. Thirty patients in whom the left internal mammary artery was used for coronary artery bypass grafting were randomized into three groups. Internal mammary artery free flow and hemodynamic measurements were evaluated before and 10 minutes after the intravenous infusion of dobutamine (3 microg x kg(-1) x min(-1)), enoximone (200 microg/kg), or epinephrine (0.05 microg x kg(-1) x min(-1)). RESULTS: A significant increase in free flow occurred only in the dobutamine group (33 +/- 7.5 and 42.2 +/- 7.9 mL/min before and after drug infusion, respectively; p = 0.013). Comparison of the increase in flow between the groups, however, showed no difference. These drugs, at doses designed to produce a positive inotropic effect, caused little increase in the free flow of the internal mammary artery. CONCLUSIONS: The use of dobutamine, enoximone, and epinephrine as low-dose positive inotropic treatments in the perioperative and postoperative periods of coronary artery bypass grafting should depend on their positive inotropic effects rather than their vasodilative effects on the arterial grafts.

Adrenergic beta-Agonists↗
PubMed1997

[Primary cardiac sarcoma treated by orthoptic cardiac transplantation. Apropos of a case].

The authors report a new case of cardiac sarcoma treated by cardiac transplantation. This treatment has been proposed for these malignant tumours of poor prognosis when simple excision is impossible, with variable results. This patient is in good general condition 20 months after transplantation. Transplantation is a therapeutic procedure which should be considered in malignant tumours limited to the heart.

Adult↗
PubMedDate not supplied

Effect of aprotinin on postoperative blood loss in off-pump coronary artery bypass surgery.

BACKGROUND AND AIM OF THE STUDY: Off-pump coronary artery bypass (OPCAB) enables a reduction in postoperative complications, particularly bleeding and transfusion. Nevertheless, a significant percentage of patients still needs transfusion. The effect of antifibrinolytic therapy on postoperative bleeding as part of OPCAB is still not widely described. The purpose of this study was to investigate the potential benefit of aprotinin in OPCAB. METHODS: We conducted a retrospective comparative study with a historical control group. Consecutive patients undergoing off-pump coronary bypass were divided in two groups: 40 patients were operated without any antifibinolytic drug (group C); 40 patients received aprotinin (group A) during surgery. Patients in group A received a bolus of 2 x 10(6) KIU during 30 minutes, followed by a continuous infusion of 0.5 x 10(6) KIU per hour until the end of surgery. The same protocol was used during the whole study period. RESULTS: Preoperative data of the two groups did not differ except for the number of grafts performed, which was higher in group A. Prothrombin time and activated clotting time increased in both groups after surgery. The use of packed red blood cells or fresh frozen plasma was not significantly different between both groups. Postoperative blood loss was significantly reduced in the aprotinin group (540 mL +/- 320 vs. 770 mL +/- 390, p = 0.006). No increase in postoperative troponin values was found in group A. CONCLUSIONS: Aprotinin significantly reduced postoperative blood loss without reducing the transfusion rate. Aprotinin was not associated with any increase in postoperative complications.

Aged↗
PubMedDate not supplied

[Salmonella aortitis complicated by rupture. Diagnostic and therapeutic problems].

We observed a case of aortitis due to Salmonella in a patient with spondylodiscitis. Outcome was fatal despite resection and grafting, extensive drainage and adapted but unsuccessful antibiotic treatment. Based on the literature, suggested treatment for patients with spondylodiscitis includes extra-anatomic bypass combined with resection of the infected tissue and adapted antibiotherapy. In these emergency cases, computed tomography is the most useful exploration and also gives the diagnosis of spondylodiscitis. It is also necessary to identify the infectious agent to adapt the antibiotics.

Aged↗