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Biomedical subjects

J C Gaux

Publications and source records attributed to J C Gaux.

At least 19 recordsLinked to original sources
PubMed2000

Spontaneous renal artery dissection revealed by helical CT angiography.

Spontaneous renal artery dissection is rare and may be misdiagnosed because its clinical presentation is confusing. Diagnosis is usually made by intra-arterial angiography. We report a case where a spontaneous renal artery dissection was initially misdiagnosed as a renal abscess. Diagnosis was made later with helical CT for suspicion of renal artery stenosis in a patient with recent onset of hypertension. This unusual case shows that helical CT can be useful for non-invasive diagnosis of renal artery dissection.

Abscess↗
PubMed2000

[Pulmonary embolism: is scintigraphy useful after initial angio-CT?].

PURPOSE: To assess the value of ventilation-perfusion scintigraphy after an initial helical CT with absence of pulmonary embolism (PE). MATERIAL: and methods. Twenty eight consecutive patients with clinical suspicion of pulmonary embolism underwent helical CT scan to look for an intra-luminal clot. When the CT-scan was positive for PE, diagnosis was retained. If the result was negative, a ventilation-perfusion scintigraphy was performed. If the result was also negative, diagnosis of PE was excluded. In case of discrepancy, a pulmonary angiography was performed and used as gold-standard. RESULTS: Twenty-one patients showed PE at CT-angio and 7 did not. Two of these 7 had normal or low probability scintigraphy, excluding diagnosis of PE. One had intermediate V/P scan and 4 had high probability V/P scan. For these 5 discrepancies, none of them had PE on angiography. CONCLUSION: In this population, scintigraphy was not appropriate after a negative CT-angio for PE. In case of persistent doubt after a normal initial helical CT, pulmonary angiography is required

Aged↗
PubMed2000

[Left ventricular thrombus revealed by electron bean computed tomography, in a patient with antiphospholipid syndrome].

The authors report a case of a 48 year old woman admitted to hospital because of digital ischemia, in a context of antiphospholipid syndrome. The electrocardiogram-triggered electron beam computed tomography revealed an apical thrombus associated with a thinning left ventricular wall, suggesting painless myocardial infarction. The diagnosis was secondary confirmed by coronarography.

Antiphospholipid Syndrome↗
PubMed1999

Preoperative assessment of the efficacy of distal radial artery ligation in treatment of steal syndrome complicating access for hemodialysis.

Hand ischemic steal syndrome due to a forearm arteriovenous fistula is a rare occurrence. We report here a case in which we applied a new diagnostic method to assess the efficacy of distal radial ligation to treat this syndrome. A favorable comparison of distal radial artery pressure measurements before and after temporary occlusion of the artery with a balloon catheter indicated that perfusion of the hand would be dramatically improved after surgical artery ligation.

Angiography↗
PubMed1999

[Immediate results and 2-year follow-up of percutaneous transluminal angioplasty in intermittent claudication in patients over 70 years of age].

PURPOSE: This retrospective study was aimed at assessing immediate and mid-term results of percutaneous transluminal angioplasty for intermittent claudication in patients over 70 years of age, and the overall morbidity and mortality during follow-up. METHODS: Fifty-one percutaneous transluminal angioplasties were performed between 1993 and 1997 in 30 men and eight women (mean age: 78 +/- 5.2; range 71-91) for intermittent claudication (walking distance < 250 m). RESULTS: Angioplasties were supra-inguinal in 24 cases (47%) and infra-inguinal in 27 cases (53%). Clinical success (walking distance > 500 m) was obtained in 92% of the patients. Significant complications (5.9%) were inguinal hematoma requiring subsequent surgery in one patient and common femoral false aneurysms in two patients. Mean duration of hospitalization was 3 days and a half. After a mean follow-up of 25 months (range: 4-51 months), improvement in the walking distance was still present in 31 patients (82%). The condition of seven (18%) patients did not improve. No patient presented with critical ischemia. As well, no patient underwent surgical revascularization or amputation. However, the condition of eight (21%) patients required subsequent percutaneous transluminal angioplasty. Four (10.5%) patients died. Following percutaneous transluminal angioplasty, six (18%) patients presented with a major non-fatal clinical event. All the patients lived at home. CONCLUSION: Percutaneous transluminal angioplasty has little immediate risk when lesions are accessible and leads to positive mid-term clinical results in the treatment of intermittent claudication in patients over 70 years of age.

Age Factors↗
PubMed1999

Idiopathic dilatation of the pulmonary artery: report of four cases.

Idiopathic dilatation of the pulmonary artery (IDPA) is a rare congenital disease which is usually detected fortuitously on chest x-ray, thus radiologists must be aware of this clinical entity. This report describes four cases to which Magnetic Resonance Imaging (MRI) played a major role in diagnosing IDPA and in detecting the concomitant findings observed in this disease. MRI is a non-invasive procedure with many advantages for the accurate and reproducible measurement of artery structures, which makes it the preferred option for combined use with echocardiography in the diagnosis and follow-up of patients with IDPA.

Adolescent↗
PubMed1999

Pulmonary arterial resistance: noninvasive measurement with indexes of pulmonary flow estimated at velocity-encoded MR imaging--preliminary experience.

Cardiac output and pulmonary vascular resistance (PVR) were measured in 19 patients by means of catheterization of the right side of the heart. Results were compared with the cardiac output and indexes of pulmonary arterial blood flow estimated with velocity-encoded magnetic resonance (MR) imaging. Correlations were good between estimates with right-sided heart catheterization and those with velocity-encoded MR imaging. By providing accurate pulmonary arterial blood flow measurements, velocity-encoded MR imaging allowed distinction of patients with high PVR from subjects with normal PVR.

Adult↗
PubMed1999

Electron beam CT features of the pulmonary artery in Takayasu's arteritis.

OBJECTIVE: Pulmonary artery involvement in Takayasu's arteritis is suggestive of the disease. Our aim was to use electron beam CT to study pulmonary artery changes in patients with Takayasu's arteritis. CONCLUSION: Diffuse wall thickening and dilatation or stenosis were significantly more frequent on CT in patients with Takayasu's arteritis than in the control subjects. Knowledge of these findings may be of value when assessing pulmonary artery involvement and thus may be helpful for the diagnosis of Takayasu's arteritis.

Adult↗
PubMed1999

Interobserver variability in the interpretation of renal digital subtraction angiography.

OBJECTIVE: Our purpose was to analyze interobserver variability in the interpretation of renal digital subtraction angiography and to describe the main factors associated with observer discrepancies. MATERIALS AND METHODS: Forty-nine cases of unilateral atheromatous renal artery stenosis of more than 60% were quantified first by local investigators in a multicenter study and then by five other radiologists. Differences between radiologists for the minimum diameter (Dmin), the reference diameter (Dref), and the percentage of stenosis of the renal arteries were analyzed. Interpretations by the local investigators were then compared with the gold standard, defined as the mean for the five radiologists. RESULTS: The average SD for estimation of all renal artery stenoses by all radiologists was 7% for stenosis percentage, 0.5 mm for Dmin, and 0.7 mm for Dref. Main discrepancies occurred more frequently in cases of weakly opacified renal artery stenosis and poststenotic dilatation. The observations of local investigators disagreed by more than two SDs (14%) with the gold standard for 11 of 49 cases (22%). CONCLUSION: The accuracy of digital subtraction angiography in renal artery interpretations is poor because of variations in evaluating both Dmin and Dref. Precise and reproducible methods for quantification of renal artery stenosis are required.

Adult↗
PubMed1999

[Spontaneous regression of a false aneurysm of the ascending aorta following surgery for dissection].

We report the case of a 50-year-old man admitted to hospital for a type A aortic dissection. After conventional surgical repair, he was asymptomatic and underwent computed tomography imaging at 15 days, 3 and 6 months. The first CT scan showed a small perigraft circulating false aneurysm which totally disappeared on the last exam. This case emphasizes the potential role of CT scan in the follow-up of patient after aortic surgery and the likely favorable outcome of some false aneurysm.

Aortic Dissection↗
PubMed1999

[Role of endovascular treatments in the management of arteriopathies of the aged subject].

Endovascular procedures have deeply modified the treatment of patients with peripheral arterial diseases. However risks of transluminal angioplasty are increased with patient age. In patients with acute ischemia by distal embolism or in situ thrombosis percutaneous thromboaspiration is an alternative to the Fogarty catheter. In patients with chronic critical ischemia, revascularization is necessary. Risks of surgical treatment are rather in favour of endovascular procedures. In patients suffering of intermittent claudication, results of a series of 38 patients confirm the efficacy of angioplasty. Thus endovascular procedures can be proposed in alternative to medical treatment to patients over 70 years of age.

Aged↗
PubMed1998

Cardiac metastatic melanoma investigated by magnetic resonance imaging.

There is a high rate of cardiac involvement in malignant melanoma (MM), but such cardiac metastases are usually diagnosed late. This report describes four cases with different clinical presentations of MM cardiac involvement that were investigated by magnetic resonance imaging (MRI). The MM cardiac involvement was asymptomatic in one case, detected because of a superior vena cava syndrome in a second, and because a tamponade in the remaining two cases. MRI permitted the diagnosis of cardiac metastases of MM, which was not made by echocardiography in one case. By precisely detecting the extent of the tumors, MRI was a great help in management, especially when an isolated cardiac metastasis was suitable for surgical ablation (two cases). Because both clinical signs and transthoracic echocardiogram are not very sensitive for diagnosing MM myocardial involvement, MRI can help provide such a diagnosis and ensure better treatment-monitored decisions.

Aged↗
PubMed1998

Sialic acid content of LDL in coronary artery disease: no evidence of desialylation in subjects with coronary stenosis and increased levels in subjects with extensive atherosclerosis and acute myocardial infarction: relation between desialylation and in vitro peroxidation.

We recently showed that sialic acid content of LDL was not a marker of early cardiovascular disease (Arterioscler Thromb Vasc Biol. 1995;15:334-339). Here, we investigated this parameter in patients with advanced coronary artery disease (CAD). We first examined 100 patients having undergone coronary angiography. The distribution of LDL sialic acid values was very similar in subjects with no coronary stenosis (31.3+/-3.7 nmol/mg LDL protein, mean+/-SD) and those with > or = 75% stenosis in at least one main coronary artery or > or = 50% stenosis in at least two main coronary arteries (32.1+/-5.5 nmol/mg LDL protein). In contrast, LDL sialic acid content was significantly increased in patients with both coronary stenosis and peripheral arterial atherosclerotic lesions compared with those with either no lesion or only one or the other type of lesion. We then examined LDL sialic acid content in 20 patients with acute myocardial infarction. LDL sialic acid content was significantly higher (35.9+/-3.2 nmol/mg LDL protein) than that in the CAD(-) control group. These data suggest that LDL sialic acid content increases with the extension of atherosclerosis and its progression to acute complications. To explain the discordance with Orekhov and coworkers (Atherosclerosis. 1991;86:153-161), who showed that LDL sialic acid content in patients with advanced CAD was lower than that in healthy subjects, we studied the time courses of sialic acid, TBARS, and vitamin E levels in LDL dialyzed in different experimental conditions. A continuous decrease in both sialic acid and vitamin E levels and an increase in TBARS levels were observed in LDL samples containing less than 1 mmol/L EDTA, the intensity and rapidity of which varied with the EDTA concentration in the buffer. Our data support the idea that desialylation may result from in vitro peroxidation of LDL.

Acute Disease↗
PubMed1997

Percutaneous recanalization of acutely thrombosed vessels by hydrodynamic thrombectomy (Hydrolyser).

A hydrodynamic thrombectomy catheter was prospectively evaluated for the treatment of recently thrombosed vessels. A total of 52 consecutive patients (42 males and 10 females; mean age 64 +/- 15 years) presenting with acute or subacute occlusion of dialysis shunts (n = 25), peripheral bypass (n = 14) or native arteries (n = 15) were treated with the Hydrolyser (Cordis Europa NV, Roden, The Netherlands). Mean occlusion time was 4 days (range 1-17 days) and mean thrombus length 19 +/- 11 cm. The Hydrolyser was effective and fast in removing thrombus, regardless of the thrombus length. No major complications were reported. The immediate procedure success rates were 82, 100, 87 and 79 % for Brescia Cimino, dialysis shunt, native arteries and bypass grafts, respectively. Adjunctive thrombolysis (applied for persistence of residual thrombus or thrombosed distal vessels too small for hydrolytic thrombectomy) was required in 4 % of thrombotic dialysis shunts, in 20 % of native arteries and in 50 % of bypass graft occlusions. On angiographic controls, distal embolizations were reported only in native arteries (13 %) and bypasses (14 %); all were successfully treated percutaneously, except for one case treated by Fogarty balloon. Cumulative primary patency rates were respectively at 6 months 56, 62, 78 and 65 % for each indication. We conclude from this preliminary clinical study that hydrodynamic thrombectomy with a Hydrolyser is a promising technique to treat acute occlusions. This device can reduce complications as well as the time required to remove large amounts of thrombus and the use of expensive thrombolytic drugs.

Angiography↗
PubMed1997

Automatic stenosis detection and quantification in renal arteriography.

Visual assessment of the degree of renal artery stenosis on renal arteriography has a large inter- and intraobserver variability. This degree is usually estimated by the ratio between the most narrowed portion of the artery and the reference diameter. The latter is a priori unknown information and thus operator dependent. The objective of the present work was to test the performances of a computer system that was designed to analyze and quantify lesions on 2D renal arteriograms. The main hypothesis was to consider that the most frequent diameter computed along the artery was a good candidate to approximate the reference diameter. Forty nine patient images were collected from the EMMA randomized trial, a multicenter study comparing two treatment strategies in unilateral atheromatous renal artery stenosis of at least 60%. For each image, the degree of stenosis was evaluated by five independent experts and the mean value was used to represent the gold standard for the computer system. The system is based on a fuzzy automaton and performs a syntactic analysis of the arterial segment providing automatic and reproducible quantification of lesions. Both the radiologist caring for the patient and the system were compared to the gold standard. Compared to individual radiologists, the computer system gave a more precise estimation of percent stenosis and did not over or under estimate the severity of the lesion.

Fuzzy Logic↗
PubMed1997

[Renal stenosis in hypertensive children. Doppler/arteriographic correlation].

To evaluate the reliability of Doppler-ultrasonography in identifying children with renal artery stenosis among those with hypertension, we compared Doppler ultrasonography results in 29 hypertensive children (mean age: 8.3 +/- 4.7 years) with angiography. Doppler-ultrasonography and arteriography were performed within a period less than two months. First, we established normal values in 40 normotensive children (mean age: 8.4 +/- 4.5 years). The diagnosis of renal artery stenosis was settled when maximal systolic velocities where > or = to 1.70 m.s-1. Peak systolic velocities values of Doppler-ultrasonography were significantly higher in patients with proven angiographic renal artery stenosis (3.56 +/- 0.70 m.s-1) than in hypertensive patients with normal renal arteries at angiography (1.02 +/- 0.29 m.s-1, p < 0.0001), and than in normotensive healthy children (1.05 +/- 0.33 m.s-1, p < 0.0001). We observed 3 false negative and 2 false positive diagnoses with Doppler-ultrasonography. Of the 3 false negatives, one had a stenosis on a right and posterior segmental artery and the other had bilateral and multiply intra-renal artery stenosis with few hemodynamic significance. The 2 false positives were due to a sinuous main renal artery and to a technical mistake, respectively. In another patient, Doppler-ultrasonography revealed a tight main renal artery stenosis, not detected by arteriography. Renal artery stenosis was subsequently confirmed by a second arteriography. Our results showed a sensitivity of 88%, a specificity of 93%, a positive predictive value of 92% and a negative predictive value of 89%, demonstrating the reliability of Doppler-ultrasonography for the diagnosis of renal artery stenosis in hypertensive children. With the use of a rigorous methodology and the increasing experience of the operators, diagnostic errors of renal artery stenosis are currently avoidable. Nevertheless, it is not excluded that intra-renal artery stenosis with few hemodynamic significance might be missed by Doppler-ultrasonography.

Adolescent↗