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Olivier Chavanon

Publications and source records attributed to Olivier Chavanon.

14 recordsLinked to original sources
PubMed2006

Emergency endovascular stent graft repair for acute blunt thoracic aortic injury: a retrospective case control study.

OBJECTIVE: To compare surgical and endovascular stent graft (ESG) treatment of blunt thoracic aortic injury (BAI) in the emergency setting. DESIGN AND SETTING: Retrospective case control study in two surgical intensive care units of a university hospital. PATIENTS: 30 patients who presented with BAI between 1995 and 2005: 17 treated surgically and 13 by ESG. The two groups were comparable for the severity of trauma and mean delay before treatment; the mean age was higher in the ESG group (46+/-18 vs. 35+/-15 years). RESULTS: In the surgical group time spent in the operating theater was longer (310+/-130 vs. 140+/-48 min) and blood losses higher (2000+/-1300 vs. no significant bleeding); aortic clamping time was 48+/-20 min. The mortality rate was 15% with ESG (n=2) and 23% with surgery (n=4). Complications of the procedure were more frequent in the surgical group (1 vs. 7). In the ESG group there was one pulmonary embolism. In the surgical group there were three neurological complications, one acute aortic dissection, one perioperative rupture, one periprosthetic leak, and one septic shock. Two complications (postoperative aortic dissection and paraplegia) appeared in the same patient in the surgical group. Intensive care unit length of stay, duration of mechanical ventilation, and catecholamine support were similar in the two groups. CONCLUSIONS: Stent graft for emergency treatment of BAI is efficient and is associated with fewer complications than surgical treatment.

Adult↗
PubMed2005

Functional coupling of adenine nucleotide translocase and mitochondrial creatine kinase is enhanced after exercise training in lung transplant skeletal muscle.

Mechanisms responsible for limitation of exercise capacity in lung transplant recipients (LR) and benefits gained by exercise training were studied. Mitochondrial respiration parameters, energy transfer, and cell structure were assessed in vastus lateralis biopsies using the permeabilized fiber technique with histochemical and morphometric measurements. Twelve male controls (C) and 12 LR performed exercise training over 12 wk. Before exercise training, there were strong correlations between exercise capacity (maximal O(2) consumption and endurance time at 70% maximal power output) and cellular events, as assessed by percentage of type I fibers and apparent K(m) for exogenous ADP. Anticalcineurins were not involved in LR exercise limitation, since there were no differences in maximal mitochondrial rate of respiration before exercise training and no abnormalities in respiratory chain complexes compared with C. Training resulted in a significant increase in physiological parameters both at the cellular (apparent K(m) for exogenous ADP and stimulating effect of creatine) and integrated (maximal O(2) consumption, power output at ventilatory threshold, maximal power output, and endurance time at 70% maximal power output) levels in LR and C. After the training period, improvements in maximal O(2) consumption and in maximal mitochondrial rate of respiration were noted, as well as changes in endurance time and percentage of type I fibers. Because there were no changes in diameters and fiber types, baseline alteration of apparent K(m) for exogenous ADP and its improvement after training might be related to changes within the intracellular energetic units. After the training period, intracellular energetic units exhibited a higher control of mitochondrial respiration by creatine linked to a more efficient functional coupling adenine nucleotide translocase-mitochondrial creatine kinase, resulting in better exercise performances in C and LR.

Adaptation, Physiological↗
PubMed2005

Aortic arch embolization of an Amplatzer occluder after an atrial septal defect closure: hybrid operative approach without circulatory arrest.

Percutaneous closure of the secundum type atrial septal defects is becoming increasingly popular. We report the case of a 49-year-old man who presented for an unusual embolization of an Amplatzer occluder (AO) 6 weeks after a percutaneous closure of his secundum type atrial septal defect. Emergency cardiac surgery was performed and the device was safely removed by a combined surgical and endovascular approach with no need of circulatory arrest or of profound hypothermia.

Aorta, Thoracic↗
PubMed2005

Esophageal fistula after endovascular treatment in a type B aortic dissection of the descending thoracic aorta.

We report a type B aortic dissection treated with stenting of the descending thoracic aorta that subsequently developed an ischemic necrosis of the esophagus with a posterior mediastinum abscess. The surgical treatment consisted of an extra-anatomic bypass to revascularize the supra-aortic trunks and the distal abdominal aorta through a middle sternal laparotomy, the resection of the thoracic aorta, and the drainage of the mediastinal abscess. Despite this aggressive surgical approach and an initial favorable postoperative course, the patient suddenly died 3 weeks later, likely from a rupture of the aortic stump.

Aortic Dissection↗
PubMed2005

CASPER, a Computer ASsisted PERicardial puncture system: first clinical results.

Pericardial puncture is the percutaneous insertion of a needle into the pericardial space to drain a pathological pericardial effusion. The challenge for the operating surgeon is to reach percutaneously a target zone in the vicinity of the mobile heart, in a soft-tissue environment. The surgeon's ability to accomplish this depends on his own mental picture of the effusion. CASPER is a navigation software using an optical localizer which assists the surgeon by enhancing the representation of the effusion and guiding the needle's progress. Using a localized and calibrated echographic probe, the surgeon acquires a set of images in the region of interest. This zone is then manually segmented on each image, a common zone is computed, and the surgeon defines a trajectory for the needle. During the puncture procedure, the surgeon follows the position of the localized needle on a computer monitor. After initial validation on an experimental phantom, a feasibility study was performed using canine and porcine models. The optical localization device was changed from an Optotrak to a Polaris device for easier use in the clinical setting. Prior to clinical application, various tests were performed concerning the mobility of the thoracic cage, the reproducibility of the thoracic position over several apneas, and the stability of anatomic structures relative to the thoracic cage. Finally, a first clinical application was successfully performed using this system. The present paper reports on these last two stages.

Echocardiography↗
PubMed2002

Coronary artery bypass grafting with left internal mammary artery and right gastroepiploic artery, with and without bypass.

BACKGROUND: Total arterial and off-pump revascularization are increasingly used in coronary artery bypass grafting. This study describes our experience with the exclusive use of both left internal thoracic artery and gastroepiploic artery by means of a median sternotomy, with and without cardiopulmonary bypass, in a subgroup of patients with two-vessel disease. METHODS: From January 1995 to July 2000, 171 consecutive patients were reviewed in a prospective database. Ninety-one patients underwent coronary artery bypass grafting without cardiopulmonary bypass (group A), and 80 patients were operated on under cardiopulmonary bypass with aortic cross-clamp and cardioplegia (group B). RESULTS: Patient data were similar in both groups except for the Euroscore (mean; 3.4+/-6.1, group A versus 2.5+/-4.5, group B; Euroscore > 6: 26.4%, group A versus 10%, group B; p < 0.05) and ejection fraction (mean, 54.6%+/-15.8%, group A versus 63.1%+/-12.7%, group B; p < 0.001). Severe aortic calcification was present in 6 group A patients, versus no patient in group B. Operative time was shorter in group A (185 versus 213 minutes, p < 0.0001), with less distal anastomoses (2.26 versus 2.5, p < 0.05). Conversion to cardiopulmonary bypass occurred in 1 patient, who was excluded from the study. Bleeding was higher in group A (852.6+/-288 mL versus 712.4+/-274 mL, p < 0.05), but transfusion was similar in both groups. Atrial fibrillation, postoperative inotropic support, and hospital stay were similar in both groups. Myocardial infarction was less frequent in group A (1 versus 4). Postoperative intraaortic balloon pump was used in 2 patients (group B). One patient died (group A) and 1 had an embolic stroke (group B). After discharge, 2 more patients died (group A, day 91; group B day 141), and 1 patient suffered an embolic stroke (group B). One patient in each group presented with dysfunction of the gastroepiploic artery graft requiring successful percutaneous transluminal angioplasty on the right posterolateral artery. CONCLUSIONS: These results suggest that off-pump coronary artery bypass grafting using the left internal thoracic artery and gastroepiploic artery is safe even in high-risk patients. This approach allows an absolute no-touch technique of the aorta.

Aged↗
PubMed2002

Hemodynamic changes during off-pump CABG surgery.

OBJECTIVES: The purpose of this study was to assess the patients' hemodynamics during off-pump coronary artery bypass graft (OPCABG) surgery. METHODS: Continuous monitoring of the mean systemic arterial pressure (SAP), mean pulmonary arterial pressure (PAP), mixed venous oxygen saturation (SvO(2)) and cardiac output index (COI) was done on 55 patients undergoing complete OPCAB revascularization. Hemodynamic changes were recorded at the completion of the anastomosis before releasing coronary snaring and stabilization and compared to baseline. RESULTS: The mean age of the patients was 66.4+/-9.2 years, and on average 3.3+/-0.8 grafts per patient were performed. The average SAP drop after manipulations was -8.3+/-16.9 mmHg for the left anterior descending artery (LAD), -13.5+/-19.6 mmHg for the diagonal artery (DG), -14.6+/-13 mmHg for the optuse marginal artery (OM), and -14.2+/-13.5 mmHg for the right coronary artery. This was significant for all territories (P<0.01). The PAP significantly increased in all territories except OM (LAD: 3.7+/-6.3 mmHg, DG: 4.3+/-8.6 mmHg, OM: 1.1+/-7.2 mmHg, posterior descending artery: 2.7+/-5.6 mmHg; P<0.05). Variations in COI were significant in all territories (P<0.01) but more significantly in LAD and DG territories (-15+/-3% and -13+/-9%, respectively). The SvO(2) variations were <10% for all territories and reached only borderline significance (P=0.05) in all territories except OM. All these hemodynamic changes were well tolerated by all patients. CONCLUSIONS: Manipulation of the beating heart during OPCABG surgery brings significant fluctuations in the patients' hemodynamics. Mean PAP increase and COI drop were more significant during manipulation of the anterior territories suggesting a more severe diastolic restrictive disease during anterior wall manipulation.

Aged↗
PubMed2002

The 5-series F(2)-isoprostanes possess no vasomotor effects in the rat thoracic aorta, the human internal mammary artery and the human saphenous vein.

1. Among the F(2)-isoprostanes, the 15- and the 5-series are currently used as markers of lipid peroxidation in vascular diseases. 15-F(2t)-IsoP (also named iPF(2 alpha)-III) exerts a vasoconstriction in most vessels, whereas no data is available concerning 5-F(2t)-IsoP (also named iPF(2 alpha)-VI), which is more abundant in plasma. 2. The aim of this study was to determine whether 5-F(2t)-IsoP possess any vascular effects on various vessels including the isolated rat thoracic aorta, the human internal mammary artery and the saphenous vein. 3. In organ baths, 5-F(2t)-IsoP and its 5-epimer did not affect the basal tone of any vessel, unlike 15-F(2t)-IsoP. These compounds possessed no antagonist effects on 15-F(2t)-IsoP-induced contractions, No dilator effect was observed in comparison with sodium nitroprusside and acetylcholine on the rat aorta. 4. In conclusion, we show that unlike 15-F(2t)-IsoP, 5-F(2t)-IsoP and its 5-epimer possess no vasomotor effects and as such are unlikely to be involved in the pathogenesis of vascular diseases. Further studies are required to test whether these mediators may have effects on systems not being measured in the current study.

Animals↗
PubMedDate not supplied

Right ventricular function after coronary surgery with or without bypass.

BACKGROUND AND OBJECTIVE: Myocardial protection during aortic clamp period may sometimes be inadequate, especially for the right. The aim of this study was to compare right ventricle function after cardiac surgery with or without bypass. METHODS: Patients undergoing multivessel coronary surgery with proximal severe right coronary lesion were included in a prospective observational cohort study including 29 patients undergoing coronary surgery with or without bypass. All patients were monitored with a pulmonary artery catheter with continuous right ventricular function. Right ventricular ejection fraction was measured at the arrival in ICU, 1, 3, 6, and 18 hours later. RESULTS: The number of grafts that was higher in the bypass group (4.0 +/- 1.3) than in the off-pump group (2.6 +/- 0.6, p = 0.001). In the on-pump group, the right ventricular ejection fraction significantly decreased from 32.9 +/- 2.8 at arrival in ICU to 26.1 +/- 2.4, 6 hours later whereas in the off-pump group, it did not significantly change (32.4 +/- 1.8 to 31.9 +/- 2.3). Meanwhile, at the same time intervals, CVP was significantly lower in the off-pump group. CONCLUSIONS: In patients with severe right coronary stenosis, off-pump cardiac surgery seemed to provide better right ventricular protection.

Adult↗