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Dive into the research topics where Olivier Chevallier is active.

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Featured researches published by Olivier Chevallier.


The Journal of Clinical Endocrinology and Metabolism | 2016

Effect of liraglutide therapy on liver fat content in patients with inadequately controlled type 2 diabetes. The Lira-NAFLD study

Jean-Michel Petit; Jean-Pierre Cercueil; Romaric Loffroy; Damien Denimal; B. Bouillet; Coralie Fourmont; Olivier Chevallier; Laurence Duvillard; Bruno Vergès

Background: Nonalcoholic fatty liver disease is very frequent in type 2 diabetes, with increased risk of further development of liver fibrosis. Animal studies have shown that GLP-1 receptor agonists may reduce liver lipogenesis. However, data in humans are scarce. Objective: To study the effect of liraglutide 1.2 mg/d on liver fat content (LFC) in patients with uncontrolled type 2 diabetes and to evaluate the factors potentially associated with liraglutide-induced modification of LFC. Design, Setting, Participants: LFC was measured by proton magnetic resonance spectroscopy before and after 6 months of liraglutide treatment in 68 patients with uncontrolled type 2 diabetes mellitus. Intervention: Liraglutide 1.2 mg/d. Outcome measure: Change in LFC. Results: Treatment with liraglutide was associated with a significant decrease in body weight, HbA1C, and a marked relative reduction in LFC of 31% (P < 0.0001). No significant modification of LFC was observed in a parallel group of patients 6 months after intensification of the antidiabetic treatment with insulin. The reduction in LFC and body weight were highly correlated (r = 0.490; P < 0.0001). In multivariate analysis, the reduction in LFC was independently associated with baseline LFC (P < 0.0001), age (P = 0.010), and reduction in body weight (P < 0.0001), triglycerides (P = 0.019), and HbA1c (P = 0.034). In the patients who had no significant decrease in body weight, no significant reduction in LFC was observed. Conclusions: Six months of treatment with liraglutide 1.2 mg/d significantly reduced LFC in patients with inadequately controlled type 2 diabetes and this effect was mainly driven by body weight reduction. Further studies are needed to confirm that this reduction in LFC may significantly reduce fibrosis progression.


Quantitative imaging in medicine and surgery | 2015

Current role of multiparametric magnetic resonance imaging for prostate cancer.

Romaric Loffroy; Olivier Chevallier; Morgan Moulin; Sylvain Favelier; Pierre-Yves Genson; Pierre Pottecher; G. Créhange; Alexandre Cochet; Luc Cormier

Multiparametric magnetic resonance imaging (mp-MRI) has shown promising results in diagnosis, localization, risk stratification and staging of clinically significant prostate cancer, and targeting or guiding prostate biopsy. mp-MRI consists of T2-weighted imaging (T2WI) combined with several functional sequences including diffusion-weighted imaging (DWI), perfusion or dynamic contrast-enhanced imaging (DCEI) and spectroscopic imaging. Recently, mp-MRI has been used to assess prostate cancer aggressiveness and to identify anteriorly located tumors before and during active surveillance. Moreover, recent studies have reported that mp-MRI is a reliable imaging modality for detecting local recurrence after radical prostatectomy or external beam radiation therapy. Because assessment on mp-MRI can be subjective, use of the newly developed standardized reporting Prostate Imaging and Reporting Archiving Data System (PI-RADS) scoring system and education of specialist radiologists are essential for accurate interpretation. This review focuses on the current place of mp-MRI in prostate cancer and its evolving role in the management of prostate cancer.


Canadian Journal of Cardiology | 2014

Relationship Between Fragmented QRS and No-Reflow, Infarct Size, and Peri-Infarct Zone Assessed Using Cardiac Magnetic Resonance in Patients With Myocardial Infarction

Alexandre Cochet; Olivier Chevallier; Marion Angue; Aurélie Gudjoncik; Alain Lalande; Marianne Zeller; Philippe Buffet; François Brunotte; Yves Cottin

BACKGROUND The relation between fragmented QRS complex (fQRS) and cardiac magnetic resonance parameters is poorly documented in ischemic cardiopathy. METHODS Among 209 consecutive patients, those with fQRS were compared with those without fQRS. Cardiac magnetic resonance studies with late gadolinium-enhanced sequences were done during the week after acute myocardial infarction. RESULTS fQRS was present in 113 (54%) patients, and associated with a significantly lower left ventricular ejection fraction, increased left ventricular volumes, a larger infarct size (IS), and a larger peri-infarct zone. Microvascular obstruction was more frequent in patients with fQRS (62% vs 45%; P = 0.014) and the extent of the microvascular obstruction was significantly larger (1.6% [range, 0.0-4.4] vs 0.0 [range, 0.0-2.1]; P = 0.004). Finally, the transmurality score in the 2 study populations was identical (48% vs 47%; P = 0.895). In multivariate logistic regression analysis, only IS (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.03-1.09; P < 0.001), systolic blood pressure (OR, 1.02; 95% CI, 1.01-1.04; P < 0.001), and left ventricular end-systolic volume (OR, 1.02; 95% CI, 1.00-1.03; P = 0.013) remained independent predictors of fQRS. CONCLUSIONS This study revealed that fQRS was associated with increased IS, myocardial perfusion abnormalities, decreased left ventricular ejection fraction, and increased left heart volumes. These findings show that fQRS is a reliable marker of infarct size and acute ventricular remodelling.


Quantitative imaging in medicine and surgery | 2017

Selective arterial embolization of symptomatic and asymptomatic renal angiomyolipomas: a retrospective study of safety, outcomes and tumor size reduction

Florian Bardin; Olivier Chevallier; Aurélie Bertaut; Emmanuel Delorme; Morgan Moulin; Pierre Pottecher; Lucy Di Marco; Sophie Gehin; Eric Mourey; Luc Cormier; Christiane Mousson; Marco Midulla; Romaric Loffroy

BACKGROUND Angiomyolipoma (AML) is the most common renal benign tumor. Treatment should be considered for symptomatic patients or for those at risk for complications, especially retroperitoneal bleeding which is correlated to tumor size, grade of the angiogenic component and to the presence of tuberous sclerosis complex (TSC). This study reports our single-center experience with the use of selective arterial embolization (SAE) in the management of symptomatic and asymptomatic renal AMLs. METHODS In this retrospective mono-centric study, all demographic and imaging data, medical records, angiographic features, outpatient charts and follow-up visits of patients who underwent prophylactic or emergency SAE for AMLs between January 2005 and July 2016 were reviewed. Tumor size and treatment outcomes were assessed at baseline and after the procedure during follow-up. Computed tomography (CT), magnetic resonance imaging (MRI) or ultrasonography was used to evaluate AML shrinkage. Renal function was measured pre- and post-procedure. RESULTS Twenty-three patients (18 females, 5 males; median age, 45 years; range, 19-85 years) who underwent SAE either to treat bleeding AML (n=6) or as a prophylactic treatment (n=17) were included. Overall, 34 AMLs were embolized. TSC status was confirmed for 6 patients. Immediate technical success rate was 96% and 4 patients benefitted from an additional procedure. Major complications occurred in 3 patients and minor post-embolization syndrome (PES) in 14 patients. The mean AML size reduction rate was 26.2% after a mean follow-up was 20.5 months (range, 0.5-56 months), and only non-TSC status was significantly associated with better shrinkage of tumor (P=0.022). Intralesional aneurysms were significantly more frequent in patients with hemorrhagic presentation (P=0.008). There was no change in mean creatinine level after SAE. CONCLUSIONS SAE is a safe and effective technique to manage renal AMLs as a preventive treatment as well as in emergency setting, with significant reduction in tumor size during follow-up. A multidisciplinary approach remains fundamental, especially for TSC patients. In addition to size, the presence of intralesional aneurysms should be considered in any prophylactic treatment decision.


Quantitative imaging in medicine and surgery | 2017

Endovascular management of arterial injuries after blunt or iatrogenic renal trauma

Romaric Loffroy; Olivier Chevallier; Sophie Gehin; Marco Midulla; Pierre-Emmanuel Berthod; Christophe Galland; Pascale Briche; Céline Duperron; Nabil Majbri; Christiane Mousson; Nicolas Falvo

The kidney is the third most common abdominal organ to be injured in trauma, following the spleen and liver, respectively. The most commonly used classification scheme is the American Association for the Surgery of Trauma (AAST) classification of blunt renal injuries, which grades renal injury according to the size of laceration and its proximity to the renal hilum. Arteriovenous fistula and pseudoaneurysm are the most common iatrogenic biopsy-related or surgery-related vascular injuries in native kidneys. The approach to renal artery injuries has changed over time from more aggressive intervention to more conservative observational or endovascular management, including selective transcatheter arterial embolization (TAE) and the placement of stents/stent grafts. In this article, we describe the role and technical aspects of endovascular interventions in the management of arterial injuries after blunt or iatrogenic renal trauma.


Quantitative imaging in medicine and surgery | 2018

Embolization with ethylene vinyl alcohol copolymer (Onyx ® ) for peripheral hemostatic and non-hemostatic applications: a feasibility and safety study

Romaric Né; Olivier Chevallier; Nicolas Falvo; Olivier Facy; Pierre-Emmanuel Berthod; Christophe Galland; Sophie Gehin; Marco Midulla; Romaric Loffroy

Background Onyx® is a liquid embolic agent, which is approved for the treatment of cerebral vascular lesions but still rarely used in peripheral interventional radiology. The goal of this study is to report the feasibility and safety of embolization with Onyx® for peripheral hemostatic and non-hemostatic endovascular procedures. Methods Retrospective study of all consecutive patients who underwent visceral or peripheral embolization with Onyx® for hemostatic or non-hemostatic purpose in our department between May 2014 and November 2016. Demographic data, clinical presentation, underlying etiology, culprit vessel, endovascular procedure, pain during embolization, outcomes, and follow-up data were collected. Results Fifty patients (males, 34; females, 16; mean age, 56±18 years; range, 15-89 years) were included. Twenty-nine (58%) of patients underwent hemostatic embolization for arterial (n=22, 44%) or venous (n=7, 14%) bleeding lesions, whereas 21 (42%) of patients underwent non-hemostatic embolization for arterial aneurysms (n=8, 16%), preoperative portal vein deprivation (n=6, 12%) or other indications (n=7, 14%). Onyx-18 was used in 37 (74%) patients, Onyx-34 in 9 (18%) patients, and a combination of both in 4 (8%) patients. Onyx was used alone in 25 (50%) patients and in combination with other agent in 25 (50%) patients. Mean number of Onyx® vials used was 3.7 (range, 1-17). Immediate technical success rate was 100%. Primary clinical success was achieved in all patients. Recurrent bleeding occurred in two patients. Significant pain (pain score ≥3) was noted during injection in 10 (20%) patients. No major complication or side effects were noted within 1 month. Conclusions Transcatheter embolization with Onyx® is feasible and safe in the peripheral arterial or venous vasculature for both bleeding and non-bleeding patients whatever the anatomic site.


European Radiology | 2018

CT analysis of the aorta in giant-cell arteritis: a case-control study

Pierre Emmanuel Berthod; Serge Aho-Glélé; Paul Ornetti; Olivier Chevallier; Hervé Devilliers; F. Ricolfi; Bernard Bonnotte; Romaric Loffroy; M. Samson

ObjectivesGiant cell arteritis (GCA) is a large-vessel vasculitis whose diagnosis is confirmed by temporal artery biopsy. However, involvement of large vessels, especially the aorta, can be shown by imaging, which plays an increasing role in GCA diagnosis. The threshold above which aortic wall thickening, as measured by computed tomography (CT), is considered pathological is controversial, with values ranging from 2 to 3 mm. This study assessed aortic morphology by CT scan and its diagnostic value in GCA.MethodsAltogether, 174 patients were included (64 with GCA, 43 with polymyalgia rheumatica and 67 controls). All patients had a CT scan at diagnosis or at inclusion for controls. Aortic wall thickness, aortic diameter and scores for atheroma were measured. Assessor was blinded to each patient’s group.ResultsAortic diameters and atheroma scores were similar between groups. Aortic wall thickness was greater in the GCA group, even after the exclusion of GCA patients with aortic wall thickness ≥3 mm. The receiver operating characteristic (ROC) curve showed that a wall thickness of 2.2 mm was the optimal threshold to diagnose GCA (sensitivity, 67%; specificity, 98%).ConclusionsMeasuring aortic wall thickness by CT scan is effective to diagnose GCA. The optimal threshold to regard aortic wall thickening as pathological was ≥2.2 mm.Key points• Imaging, including CT scan, plays an increasing role in GCA diagnosis• CT measurement of aortic wall thickness is useful to diagnose GCA• A 2.2-mm threshold allows the diagnosis of thickened aortic wall in GCA


CardioVascular and Interventional Radiology | 2018

Ethylene Vinyl Alcohol Copolymer as First Hemostatic Liquid Embolic Agent for Non-variceal Upper Gastrointestinal Bleeding Patients: Pros and Cons

Romaric Loffroy; Marco Midulla; Nicolas Falvo; Olivier Chevallier

To the Editor, We read with great interest the article by Tipaldi et al. recently published in Cardiovascular and Interventional Radiology and reporting safety and efficacy of transcatheter arterial embolization (TAE) using ethylene vinyl alcohol (EVOH) copolymer (Onyx ) in patients with nonvariceal upper gastrointestinal bleeding as compared to coils [1]. We have several comments. First of all, we would like to congratulate the authors for their study which represents the first series to date comparing results of TAE with Onyx versus coils in such a setting. Onyx is a biocompatible polymer, which is EVOH copolymer that is dissolved in an organic solvent—dimethylsulfoxide (DMSO). It becomes radiopaque by mixing with micronized tantalum powder. When Onyx is injected into the vessels, the DMSO rapidly diffuses, and EVOH solidifies at the tip of the catheter in a shape that conforms to the target area. The main advantage of Onyx is that, unlike other liquid embolic agents, such as cyanoacrylates, it does not adhere to the endothelial wall and catheter tip, allowing better control of delivery over the embolization procedure [2]. However, Onyx has some limitations that should be emphasized for use in interventional radiology and that the authors did not bring to attention of readers. First, DMSO can cause severe vasospasm, which is most likely to occur in the early phase of the procedure, especially in small and distal vessels. This limitation may be avoided by using no more than 0.2 ml of DMSO in the first minute of injection. Second, we find the duration of injection often time-consuming, at least under local anesthesia, depending of the amount of Onyx needed [3]. Procedural time, although not reported in this series, is often of essence when used on an emergency basis, and the use of Onyx may lead to a loss of precious time compared to other faster liquid embolic agents like glue in such a setting. Furthermore, reflux is frequent at the beginning of injection and waiting for solidification of the first cast before reinjection is often necessary, taking some additional time. Third, DMSO is volatile and is excreted via respiration and sweat. This has a typical smell not unlike that of diabetic ketoacidosis and may last a few days. The patient and ward staff should be warned to expect this [2, 3]. Last but not least, chemical irritation by DMSO is usually painful depending on the territory to be embolized. It is recommended to use sedation to ensure patient comfort during embolization. No data about tolerance and protocol used for adjuvant analgesia medication were reported in the present study. In conclusion, in our experience, TAE with Onyx is a very interesting and promising liquid embolic agent for the management of acute upper gastrointestinal bleeding. Onyx seems to provide controlled embolization due to slow polymerization which enables deep penetration with less risk of catheter gluing due to its non-adhesive nature. Currently available data in the literature are very limited. Further studies are needed to better characterize its safety profile in visceral vasculature.


Quantitative imaging in medicine and surgery | 2017

Endovascular management of a giant symptomatic gluteal artery aneurysm with selective arterial embolization

Valentin Crespy; Olivier Chevallier; Joaquim Dominguez; Caroline Kazadjian; Eric Steinmetz; Pierre Pottecher; Romaric Loffroy

A 78-year-old female presented to our department with pain and swelling in the left gluteal region. Physical examination revealed a large tender swelling in the left gluteal area simulating an abscess. However, pulsation was observed over the swelling that raised the suspicion of a vascular lesion. Therefore, contrast-enhanced computed tomography (CT) was done before trying any intervention. The scan demonstrated a large aneurysm originating from the left superior gluteal artery measuring 65 mm × 38 mm with a small intra-pelvic component and large extra-pelvic component in the gluteal area ( Figure 1 ).


Quantitative imaging in medicine and surgery | 2016

Ethylene-vinyl alcohol copolymer (Onyx®) transarterial embolization for post-traumatic high-flow priapism

Olivier Chevallier; Sophie Gehin; Alain Foahom-Kamwa; Pierre Pottecher; Sylvain Favelier; Romaric Loffroy

We report a case of high-flow priapism treated successfully with superselective embolization of the cavernous artery. A 16-year-old male developed post-traumatic priapism subsequent to a fall causing blunt perineal trauma. He presented to our hospital four days after trauma. Immediately after the injury, he suffered painless sustained incomplete erection. High-flow priapism was diagnosed on the basis of color doppler ultrasonography findings. Computed tomography scan showed a high-flow arterio-venous fistula with feeders from branches of the right internal iliac artery. Selective arteriography of the right internal pudendal artery demonstrated an arterio-cavernous fistula. The fistula was superselectively embolized with ethylene-vinyl alcohol copolymer (Onyx(®)) liquid agent and disappeared completely. Improvement was noted, with significant detumescence on table. This was later confirmed on repeat color Doppler imaging. At follow-up 3 months later, he had normal erectile function. To our knowledge, transarterial embolization of high-flow priapism with Onyx(®) has never been reported and appears to be a safe and effective treatment for managing patients with such a condition.

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Alexandre Cochet

Centre national de la recherche scientifique

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Luc Cormier

University of California

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