Biomedical subjects
Publications and source records attributed to A Ravel.
We report two cases of percutaneous transhepatic stenting of the portal vein to treat stenosis and occlusion disclosed 5 and 18 months, respectively, after orthotopic liver transplantation in two adult patients. If long-term patency is satisfactory, this technique should allow long-term management of portal vein stenosis and occlusion without the use of thrombolysis.
BACKGROUND: The solitary fibrous tumor (SFT) is a spindle-cell tumor that very rarely involves the orbit. We report a new case that we compare to reports in the literature. CASE: A 72-year-old woman presented a conjunctival inflammation of the right eye developing over 5 months with progressive proptosis. Magnetic resonance imaging revealed an extraconal and homogeneous mass, which showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images, without specificity. Histological examination of the lesion removed by anterior orbitotomy confirmed the diagnosis of the SFT of the orbit. The patient was doing well without recurrence after 9 months. DISCUSSION: The diagnosis of SFT is histological. It is a mesenchymal tumor. Immunohistochemically, the tumor cells are strongly positive for CD34 and vimentin. CONCLUSION: The SFT of the orbit is a very rare and generally benign tumor. It must be immunohistochemically differentiated from other spindle-cell tumors of the orbit. The treatment is a complete surgical excision, and long-term follow-up is necessary because recurrence may appear long after treatment.
The purpose was to illustrate that single or multirow spiral CT angiography has become the main modality for the examination of the abdominal aorta. Our multidisciplinary group investigates weekly 15 abdominal aortas, with a single slice spiral CT since 1995, and a 4 row detector spiral CT since 1999. CT scans protocols and parameters optimization for the 2 CT systems are described. Indications and results of CT to investigate the various abdominal aortic diseases are illustrated and discussed: aneurisms (pretherapeutic staging, selection of indications of endovascular stent-grafting); obstructive aorto-arteriopathies (pretherapeutic staging, follow up after endovascular revascularization); dissection (diagnosis, pretherapeutic staging, follow up); inflammatory diseases; normal patterns and principal complications after surgery. Situations where multislice CT is superior to single slice CT and compared advantages of MRI are discussed. CT is at the present time the main technique to image abdominal aorta. Multislice CT is especially interesting to explore the whole aorta, poly traumatisms, and to plan and follow up endovascular treatments.
OBJECTIVE: To evaluate immediate results, clinical improvement, long-term patency and predictive factors of long-term outcome after superficial femoral artery percutaneous angioplasty. PATIENTS AND METHODS: Restrospective monocentric study of 101 patients (142 lesions: 105 stenoses and 37 occlusions) technical results, long-term patency (19 months), and clinical improvement (27,5 months) were analyzed. A multifactorial analysis was performed. RESULTS: Technical success was obtained in 99%, complications and mortality rates were respectively 3% and 2%. At the end of follow-up, 55 patients were clinically improved (20 lost to follow-up), and femoral artery remained patent in 62 patients (10 to follow-up). Statistical analyses revealed 8 significant predictive factors of a good outcome (P<0.05): female gender, non-diabetic, at least one patent artery below the knee, AHA classification <2, no stent, treatment of an occlusion, number of dilatations<3, treatment by statins for hypercholesterolemia. CONCLUSION: Femoral superficial artery angioplasty is usually achieved with low complication rate. We found eight factors predictive of long-term outcome, to keep in mind when indications are discussed.
We studied the normal evolution over time of the diameter of the healthy descending aorta in patients suffering from aneurysm or dissection of the ascending aorta, in order to anticipate potential complications of endoprosthetic treatment in this aortic segment. During their follow-up (average 35.9 months), 52 patients suffering from aneurysm or dissection of the ascending aorta had 168 aortic MRI examinations (2-7; average 3). Measurements were taken according to conventional reference landmarks making it possible to study the evolution of the diameter of the supposed healthy descending thoracic aorta. The variations in diameter with time were on average 5 mm, and there was no significant variation in this diameter, either for early controls or for the controls carried out after more than 1 year or 3 years, whatever the age group. Thus according to our series it seems that patients with a descending aorta endoprosthesis are not exposed to graft endoleak due to inadequate contact of the prosthesis and aorta within the 5 years following its implantation.
We report on embolization in 36 cases of postpartum hemorrhage (PPH). The 36 patients with severe PPH, including one patient who had undergone an emergency hysterectomy, were transferred to the regional interventional vascular radiology unit in a mean time of 6 hours 12 min. Bilateral occlusion of the anterior trunk of the hypogastric arteries was carried out using gelatin sponge. Immediate success was achieved in all cases. In 3 cases, however, a second embolization was necessary before day 2. In 17%, complementary nonvascular surgery was performed. Complications included one puncture site false aneurysm treated by compression, two cases of regressive lower limb paraesthesia, one femoral vein thrombosis, and nonsignificant puncture site hematomas (19.5%). Long-term follow-up was conducted in 23 patients: 91% resumed regular menstrual cycles, 8.7% dysmenorrhea. New pregnancy occurred in 13% (two full-term pregnancies and one voluntary termination). Immediate efficacy, low morbidity and preservation of fertility make embolization the technique of choice for severe PPH.
PURPOSE: To retrospectively evaluate the contribution of MRI to the diagnosis of arrhythmogenic right ventricular dysplasia (ARVD). PATIENTS AND METHODS: Thirty two men and 18 women (mean age: 48.7 years) were imaged using gated spin echo scans and short axis cine MR. References were McKenna criteria (gold standard), and also what we called "strong presumption" which may correspond to early or localized patterns, but correspond to negative McKenna scores. RESULTS: One patient was claustrophobic; another one was lost to follow-up. In reference to McKenna score, diagnosis of ARVD was established in 12 patients (2 of whom had familial dilated biventricular cardiomyopathy with rhythmic expression). Sensitivity, specificity, positive predictive value, negative predictive value and prevalence were respectively: 75%, 75%, 50%, 90% and 25%. Using "strong presumption" criteria, we observed 14 true positives (with sensitivity of 82%, specificity of 87%, PPV of 78%, NPV of 90% and prevalence of 35%). CONCLUSION: In our group, MRI was always performed before angiography. In our series, right ventricular wall T1W hyperintensity was the most frequent finding.
OBJECTIVE: We conducted a retrospective analysis of short- and mid-term results of endoluminal treatment of obstruction lesions involving the terminal aorta and the initial portions of the iliac arteries in 28 patients. PATIENTS AND METHODS: Twenty-eight patients (9 women, 19 men, mean age 57.5 Years) presented 52 obstructive atheromatous lesions of the aorto-iliac bifurcation. The lesions were divided into three topographic groups (9 unilateral lesions, 19 bilateral ostial lesions, 5 widespread lesions of the terminal aorta) and identified as simple (44%) or complex (56%, more than 2 cm in length and/or calcified and/or eccentric). RESULTS: Technical success was achieved in 93% of the cases with only one hematoma of the puncture site. Primary and secondary patencies were 78.9% and 93% after a mean follow-up of 50 Months (range 4-85). Clinical outcome remained good at this term for all cases of technical success but complete resolution of the symptoms was more frequent when a stent was used (84%) than for simple balloon dilatation (49%). CONCLUSION: Percutaneous treatment of obstructive lesions of the aorto-iliac bifurcation may be proposed when possible as a first-line treatment.
To determine the evolution of the diameter of the thoracic aorta with age in order to detect dilatation more reliably by imaging, we performed a retrospective analysis of the MRI examinations of the normal thoracic aorta of 66 subjects aged 44.1+/-19.1 years (range 19.1-82.4 years) obtained between 1991 and 2000 on a Magnetom SP 42 1T apparatus (Siemens) using T1-weighted spin echo sequences with electrocardiographic synchronization. Sixteen measurements were made in the axial plane, the oblique sagittal plane in the axis of the aortic arch, and the oblique frontal plane perpendicular to the latter at the level of the ascending aorta, the arch and the descending thoracic aorta. We found an increase in the thoracic aorta diameter and a significant relationship between this diameter and the age of our subjects, wherever the measure was performed. However, there was no systematic correlation between aortic diameter and age. The aortic diameter evolved with age and a marked difference seemed to exist in measurements made in groups younger and older than 40 years. This study, conducted on a small population of 66 patients, thus helps to define a normal aortic diameter, thereby making the diagnosis of pathological dilatation of the aorta more reliable.
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Fluoroscopic nonsurgical placement of an expandable polyurethane stent is less invasive than surgery for the treatment of epiphora due to obstruction of the nasolacrimal duct. It needs to be performed with the collaboration of an ophthalmologist, using a high resolution digital subtraction imaging unit.
OBJECTIVE: Immunosuppressive treatments may be usefull when Graves' ophthalmopathy is active. We evaluated the interest of hypertrophied muscle T2 weighted signal intensity as an argument of disease activity, to help for the therapeutic decision. PATIENTS AND METHODS: 46 MRI in 37 patients with Graves' ophthalmopathy were retrospectively studied. RESULTS: During the active phase of the disease, centro-muscular hypersignal was always observed (6 cases); signal intensity was not so bright or even disappeared with immunosuppressive treatment (7 cases). We never observed hypersignal when the disease was inactive (4 cases). When there was no hypersignal on T2 weighted images, the disease was inactive in 70% cases, and of low activity in the other cases. CONCLUSION: T2 weighted centro-muscular signal intensity analyse helps for the therapeutic decision in Graves' ophthalmopathy.
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PURPOSE: To evaluate the frequency, morphology and clinical long term evolution of pineal cysts depicted on MRI. PATIENTS AND METHODS: one thousand eight hundred and forty four (1 532 women and 126 men) MRI examinations were retrospectively reviewed. Coronal and sagittal spin echo T1 weighted sequences without and with gadolinium injection were performed, completed with spin echo T2 weighted images when a cystic sellar lesion was suspected. A pineal cyst was diagnosed as a rounded well defined lesion, with fluid signal in an enlarged pineal gland. Follow-up examinations were performed to evaluate the efficacy of the treatment of the sellar lesion. RESULTS: Twenty one epiphyseal cysts (1.27%) were diagnosed in 20 women (1.31%) and one man (0.79%). Their size was 1,2 +/- 0,4 cm (0,3 to 2 cm). They were asymptomatic. In 10 patients, follow-up MRI examinations did not show any change in size. During the clinical follow-up, these twenty-one patients remained asymptomatic (6 months to 5 years). CONCLUSION: The incidental detection of a pineal cyst at MRI is not exceptional. This lesion's pattern appears characteristic and their reputation of benignity is confirmed in our study.
OBJECTIVES: Dacryographies and CT dacryographies are usually performed after catheterization of a lacrimal canaliculus. We evaluated the quality of opacification on CT scan after simple instillation of contrast medium, without any catheterization. PATIENTS AND METHODS: 39 patients (78 nasolacrimal ducts) were examined for lacrimal pathways obstruction by CT scan after instillation of diluted contrast medium. Additional CT scan imaging was performed after catheterization when the first study did not provide adequate opacification. RESULTS: CT dacryography after instillation is a well tolerated technique. In our study, it allowed detection of all pathologic lacrimal ducts; 7 normal lacrimal pathways (after catheterization) were not opacified after instillation (false positives). The sensitivity of the method was 100%, its specificity 84%. CONCLUSION: CT dacryography after instillation is a physiologic, simple and sensitive method to evaluate lacrimal obstruction. We propose it as a first step, catheterization being used only in the absence of opacification after instillation.
The retention and separation of a series of D,L dansyl amino acids (used as test solutes) on a teicoplanin stationary phase were investigated over a wide range of mobile phase (citrate buffer-methanol, 90:10, v/v) pH. An approach based on the development of various equilibria was carried out in order to describe the retention behavior of the solute in the chromatographic system. The equilibrium constants corresponding to the transfer of the anionic and zwitterionic forms of the dansyl amino acids from the mobile to the stationary phase were determined. These values allowed one to explain the decrease in the retention factor and the associated increase in the separation factor as the eluent pH was increased. Thermodynamic parameter variations were calculated so that the driving forces of the solute association with the teicoplanin phase were derived. This approach indicated that the chiral discrimination was principally controlled by the interaction between the anionic form of the solute and the stationary phase.
The aim of this study was to evaluate renal function changes after percutaneous transluminal renal artery angioplasty (PTRA) done to treat atheromatous renal artery stenosis with renal failure. Between 1990 and 1995, PTRA was performed in 99 renal failure patients (creatinine clearance less than 80 ml/min) with atheromatous stenosis of one or more native renal arteries. Indications for PTRA were chronic renal failure with poorly controlled hypertension (group A, 67 patients) or rapidly deteriorating renal function (group B, 32 patients). Renal function changes after PTRA were evaluated based on the percentages of patients with improved, stabilized, and worsened serum creatinine and creatinine clearance values, and on mean differences between final and baseline creatinine clearances. At the end of follow-up (19+/-10 months), group A had a significantly smaller creatinine clearance gain (42.9 ml/min before PTA to 44.5 ml/min after PTA, D=1.6 ml/min, in group A, vs 24.1-28.4 ml/min, D=4.3, in group B, p=0.03), and a significantly smaller percentage of improved patients (36 vs 62%) than group B. Most stenoses in group B either were bilateral or occurred on a solitary kidney ( p=0.001). Percutaneous transluminal renal artery angioplasty combined with aggressive medical treatment may be useful in maintaining or improving renal function, particularly in patients with a recent, sharp deterioration in renal function.