Search PubMed⌕ Search

Biomedical subjects

Serge Willoteaux

Publications and source records attributed to Serge Willoteaux.

15 recordsLinked to original sources
PubMed2006

Fibromuscular dysplasia of the main renal arteries: comparison of contrast-enhanced MR angiography with digital subtraction angiography.

PURPOSE: To retrospectively evaluate the sensitivity and specificity of contrast material-enhanced magnetic resonance (MR) angiography by using digital subtraction angiography as the reference standard in patients with hypertension and renal artery fibromuscular dysplasia (FMD). MATERIALS AND METHODS: Institutional review board approval was obtained, with waiver of informed consent. The results of renal contrast-enhanced MR angiography were retrospectively analyzed in 25 patients with hypertension (24 women, one man; mean age, 48 years +/- 19 [standard deviation]; age range, 18-72 years) who had FMD diagnosed on the basis of clinical and angiographic features. All examinations were performed at 1.5 T. Results were analyzed by two readers, and a third reader established a consensus in case of discrepancy. Sensitivity, specificity, and 95% confidence intervals (CIs) were calculated for FMD and for each possible type of FMD lesion ("string of pearls" appearance, stenosis, and aneurysm). A linear-weighted kappa statistic was calculated to determine agreement between digital subtraction angiography and contrast-enhanced MR angiography for the diagnosis of FMD and to determine inter- and intraobserver agreement regarding FMD diagnosis. RESULTS: Fifty main renal arteries were analyzed, 35 of which demonstrated abnormal arteriographic features of FMD (stenosis, 22 arteries; string of pearls, 21 arteries; and aneurysm, four arteries). The sensitivity and specificity of contrast-enhanced MR angiography for the diagnosis of FMD were 97% (95% CI: 83%, 100%) and 93% (95% CI: 66%, 100%), respectively. Sensitivity was 68% (95% CI: 83%, 100%), 95% (95% CI: 74%, 100%), and 100% (95% CI: 40%, 100%) for the diagnosis of stenosis, string of pearls, and aneurysm, respectively. Linear-weighted kappa statistics for inter- and intraobserver agreement regarding FMD diagnosis were 0.63 and 0.92, respectively. CONCLUSION: In patients with renal FMD, contrast-enhanced MR angiography can reliably facilitate diagnosis by demonstrating characteristic lesions.

Adolescent↗
PubMed2006

Midterm results of aortic diameter outcomes after thoracic stent-graft implantation for aortic dissection: a multicenter study.

PURPOSE: To evaluate aortic diameter outcomes after stent-graft implantation for aortic dissection in the descending thoracic aorta. METHODS: Fifty patients with type A dissection after ascending aortic surgery (n = 10), type B dissection (n = 34), or intramural hematoma (n = 6) underwent stent-graft repair in 3 centers. Thrombosis and aortic diameter were analyzed by computed tomographic angiography at different levels of the aorta before stent-graft implantation, at discharge, and at follow-up. Measurements were standardized. RESULTS: In all, 67 stent-grafts were implanted for acute (n = 18) and chronic (n = 32) dissection. Stent-graft placement was successfully performed with high technical success (100%) despite 4 major complications (iliac thrombosis in 2 cases, aortic rupture, and a type A dissection) in 3 (6%) patients. Complete thrombosis of the thoracic false lumen was observed in 42% and 63% of cases at discharge and at follow-up (mean 15 months), respectively. At follow-up, the diameters of the entire aorta (mean 5 mm, p < 0.05) and the false lumen (mean 11 mm, p < 0.0001) decreased. Diameters of the abdominal aorta remained stable in association with persistent false lumen perfusion at this level. Aortic diameter results were better in the subgroup of patients with intramural hematoma compared to patients with Marfan syndrome. Three early deaths unrelated to the stent-graft procedure occurred; 2 patients with partial thrombosis of the false lumen died in follow-up secondary to aortic diameter growth. CONCLUSION: Complete thrombosis of the false lumen by stent-graft coverage of the entry tear results in decreased diameter of the entire aorta. In patients with partial thrombosis of the false lumen, the aneurysm continues to enlarge.

Adult↗
PubMed2006

Multislice computed tomographic angiography versus digital subtraction angiography in the follow-up of nitinol stents in the superficial femoral artery.

PURPOSE: To compare quantitative and qualitative parameters obtained from digital subtraction angiography (DSA) with multislice computed tomographic angiography (MSCTA) in the follow-up of superficial femoral artery (SFA) stents. METHODS: Thirteen patients who had SMART stents implanted in the SFA were examined systematically with DSA and MSCTA (16-row scanner) at 6 months. Quantitative analysis and morphological assessment were performed on DSA images by an independent core laboratory, while the MSCTA images were analyzed by 2 radiologists in consensus. DSA measurements included stent length, minimal lumen diameter and reference diameter at mid stent and 5 mm either side of the stent, and percentage of stenosis. For MSCTA images, lumen area and the minimum, maximum, and mean diameters were also recorded. The images were analyzed qualitatively for diameter stenosis (<50%, 50% to 70%, 71% to 99%, and occlusion), bends, fractures, and calcifications. RESULTS: There were no statistical differences between lengths of stented segments, diameter measurements, or percentages of stenosis from DSA and MSCTA images. The Bland-Altman method showed good agreement between the 2 methods of measurement. MSCTA detected in-stent proliferation with a diameter stenosis <50% in all 13 cases diagnosed on DSA (there was no stenosis >50%). There were no bends or stent fractures on either set of images. The agreement between DSA and MSCTA for the presence and grading of calcifications was moderate (kappa=0.5). CONCLUSION: MSCTA provided quantitative and qualitative data comparable with DSA in the analysis of SFA nitinol stents.

Aged↗
PubMed2005

Effect of iodinated contrast agents on residual renal function in PD patients.

BACKGROUND: Residual renal function (RRF) is an important predictor of outcome in peritoneal dialysis (PD) patients. Although increasing emphasis has been placed on preserving RRF, the nephrotoxicity associated with contrast medium administration in PD patients remains a controversial issue. In the present prospective study, we evaluated the evolution of RRF 2 weeks after iodinated contrast medium administration (ICMA) in a group of stable PD patients, and compared it with that in a non-treated control group of stable PD subjects. METHODS: The study was conducted from January 2003 to October 2004. RRF was quantified by the average of 24 h urinary urea and creatinine clearance and peritoneal creatinine clearance (PcrCl) were analyzed, the levels of which were analysed prior to and 2 weeks following ICMA in 36 PD patients and also assessed at the same time points in a group of 36 PD non-ICMA control subjects, matched according to RRF characteristics. Two weeks following ICMA, the values for RRF, daily urine volume and PcrCl were assessed against those at baseline, and the evolution of RRF was compared between the two groups. In the ICMA group, this study was performed with adequate pre-hydration and a minimum dose of contrast medium. RESULTS: Compared with baseline values, RRF, daily urine volume and PcrCl were not found to be significantly different 2 weeks after ICMA (7.0+/-4.3 vs 7.2+/-4.3 ml/min/1.73 m(2), P = 0.12; 1324+/-696 vs 1360+/-755 ml/day, P = 0.5; and 41.1+/-9 vs 40.6+/-9 l/week/1.73 m(2), P = 0.6, respectively). Following ICMA, variations in RRF and daily urine volume were found to be comparable with those of the control group (0.1+/-0.5 vs 0.1+/-0.5 ml/min/1.73 m(2), P = 0.9; 36+/-440 vs 40+/-493 ml/day, P = 0.8, respectively). CONCLUSION: In this study, 2 weeks following ICMA, no accelerated decline in RRF was determined in stable PD patients with adequate pre-hydration, i.e. subjects treated under optimal circumstances compared with the control group.

Case-Control Studies↗
PubMed2005

[Diagnosis and non-invasive evaluation of a patient with obliterating arteriopathy of the lower limbs].

Obliterating arteriopathy of the lower limbs (OALL) is a pathology that manifests itself late in the natural history of an atheromatous patient. It is largely a localised pathology but should be considered as a marker for more generalised disease, for which the prognosis is modified by cardiac and cerebrovascular complications. Measurement of the systolic blood pressure index at the ankles is indispensable for initial management, with measures inferior to 0.90 correlating with an arterial stenosis of more than 50%, even in the absence of symptoms. Although the diagnosis is above-all clinical, further investigations complete the initial management by estimating the severity of the lesions, identifying the threatening lesions, allowing an overview of the general disease and a follow-up of the patient. Undoubtedly, the Doppler ultrasound remains the first-line investigation of choice. Helical computerised tomography and angiography by magnetic resonance imaging complete the initial investigation when a revascularisation procedure is envisaged, their respective indications depending on the protocols of each Vascular Centre. The walking-on-a-rolling-carpet test allows evaluation of residual functional capacity of the patient at the stage of claudication. The discovery of OALL calls for at least coronary screening, whatever be the stage of severity, with one patient in four dying of a coronary complication in 5 years. Other vascular localisations should be screened for depending on the clinical symptomatology. The medico-economic value of an extensive systematic vascular work-up is, in effect, still only demonstrated for the stage of claudication.

Ankle↗
PubMed2005

False aneurysm formation following cutting balloon angioplasty in the renal artery of a child.

PURPOSE: To report the fortuitous discovery of a false aneurysm 7 years after cutting balloon angioplasty for severe renal artery fibromuscular dysplasia in a child. CASE REPORT: A 3-year-old girl with neurofibromatosis was referred to our institution because of high blood pressure (220/160 mmHg). Computed tomography identified coarctation of the aorta and severe bilateral renal artery stenoses. The coarctation was successfully resected. One month later, bilateral renal artery angioplasty with a 3-mm balloon was unsatisfactory, so a second angioplasty one month later was done with a 3.25-mm cutting balloon. This procedure was complicated by a minimal arterial rupture, which resolved spontaneously after inflation of a regular balloon. Normal blood pressure was restored. The child was lost to follow-up until 7 years later, when recurrent hypertension (200 mmHg systolic) prompted referral again. Arteriography showed a very severe stenosis on the right side and a 30-mm false aneurysm of the left renal artery at the rupture site. Due to her age, the patient underwent surgery, which brought the blood pressure under control. CONCLUSIONS: False aneurysm of the renal arteries is a rare complication of percutaneous angioplasty. In a child, the cutting balloon would appear to be contraindicated for concentric dysplastic stenoses that are resistant to regular balloon angioplasty.

Aneurysm, False↗
PubMed2004

Imaging of aortic dissection by helical computed tomography (CT).

Aortic dissection is the most frequent cause of aortic emergency, and its outcome is still frequently fatal. The management of this pathology has changed with the development of endovascular means. Nowadays, imaging modalities are helpful in management decision-making by providing information such as identification of entry tears along the aorta and involvement of the visceral branches of the abdominal aorta. Multi-slice CT scanning now appears to be the modality of choice for complete examination of the entire aorta. We review the parameters of image acquisition and contrast injection; appearances on CT of acute and chronic dissection are illustrated. Diagnostic pitfalls in CT imaging of acute dissection are discussed. Imaging of the post-surgical aorta and of chronic dissection is outlined. Intra-mural hematoma and penetrating aortic ulcer are subtypes of aortic dissection, and their appearances on CT scanning are also presented.

Aortic Dissection↗
PubMed2004

Observations from multidetector CT imaging of different types of renal artery stents.

PURPOSE: To present an optimized protocol for acquisition and reconstruction of multidetector computed tomographic angiographic (CTA) images of the stents most commonly used in renal arteries. TECHNIQUE: CTA was performed on a 16-detector row CT scanner using 0.75-mm collimation. Multiplanar reformatted images perpendicular to the stents and 2-dimensional curved reformatted images were displayed. Two different view windows ("vascular" and "stent") were used, each adapted to the stent density, the vascular wall density, and the aortic enhancement. Five different types of stainless steel balloon-expandable stents were examined; all caused discernable artifacts. These artifacts became more prominent as the stent density increased, becoming most significant when 2 stents were positioned one inside the other. The "stent" window allowed better appreciation of the stent shape and its position compared to the aortic wall and ostial calcifications. The "vascular" window afforded a better view of the vascular lumen, in addition to visualizing the stent in several planes. CONCLUSIONS: Multidetector CTA using dedicated acquisition and reconstruction protocols is capable of visualizing the vascular lumen of different types of renal stents while avoiding metallic artifacts.

Angiography↗
PubMed2003

Relationship of intimal flap position to endovascular treatment of malperfusion syndromes in aortic dissection.

PURPOSE: To propose a classification system based on the position and extension of the intimal flap to assist in the endovascular repair of aortic dissection complicated by a malperfusion syndrome. METHODS: Forty-one patients (34 men; mean age 58 years, range 22-78) with 19 type A and 22 type B dissections complicated by a malperfusion syndrome were treated with stenting, fenestration, or both for the peripheral ischemia. A retrospective review of the preprocedural imaging studies (computed tomographic angiography and arteriography) was performed to determine and categorize the position of the aortic intimal flap. In type 1, the flap was either parallel to or perpendicular to the origin of the malperfused collateral artery; type 2 referred to extension of the dissection into the collateral vessel, while type 3 represented the presence or absence of an avulsed branch ostium. RESULTS: Patients treated with stenting (n=19) alone had type 2 or type 3 arterial dissections, whereas the 12 patients who were treated with fenestration alone had type 1 lesions. Ten patients treated with stenting and fenestration had arterial lesions in which a type 1 dissection was associated with types 2 or 3. CONCLUSIONS: This appearance-based imaging approach combined with the symptoms of malperfusion syndromes during aortic dissection can help guide the endovascular treatment strategy.

Adult↗
PubMed2002

Preoperative fenestration for type A acute aortic dissection with mesenteric malperfusion.

We report a case of a 71-year-old man presenting with acute type A aortic dissection and mesenteric ischemia due to extension of the intimal flap to the mesenteric artery. Because of the severity of the abdominal symptoms, surgical correction of the ascending aorta was delayed. Preoperative percutaneous fenestration was performed successfully, allowing ascending aortic replacement 6 days later. Transverse colon stenosis secondary to preoperative ischemia occurred in the postoperative course. The patient was discharged from hospital with normal intestinal transit 72 days later.

Aged↗
PubMed2002

Cortical thickness: an early morphological marker of atherosclerotic renal disease.

BACKGROUND: Although kidney size is still the most commonly used morphological parameter, it is not sensitive enough for early detection of atherosclerotic renal disease (ARD). The purpose of this work was to evaluate morphological abnormalities on both post-stenotic and contralateral kidneys, by using spiral computed tomography angiography (CTA). METHODS: Spiral CTA was performed in 49 hypertensive patients. Renal diameters, renal length, and cortical thickness were measured in 26 post-stenotic kidneys, 26 contralateral kidneys and 46 control kidneys. Mean cortical thickness, cortical area, and medullary length were calculated. RESULTS: The right and left control kidneys were of comparable morphology. The post-stenotic kidneys showed significant cortical atrophy. The contralateral kidneys also underwent cortical disease, as judged by comparison with control kidneys. A threshold of 800 mm2 was identified for the cortical area that allowed us to distinguish control kidneys from post-stenotic kidneys. Similarly, a threshold of 8 mm was identified for mean cortical thickness. Renal length was still within normal range in all kidney groups. The measurement of superior pole segments appeared to be more sensitive than measurement at other locations for identifying significant intrarenal lesions. There was no significant correlation between clinical and morphological parameters. CONCLUSIONS: These results suggest that cortical parameters are more sensitive for early diagnosis of ARD than kidney size. Cortical atrophy should be a useful marker for guidance for revascularization.

Adult↗
PubMed2002

Renal atrophy in atherosclerotic renovascular disease: gradual changes 6 months after successful angioplasty.

OBJECTIVE: To assess renal morphology using spiral computed tomographic angiography (CTA) before and 6 months after angioplasty of unilateral atherosclerotic renal artery stenosis (RAS). METHODS: Spiral CTA scans from 14 hypertensive patients (7 men; mean age 57.4 +/- 13.1 years) with significant RAS were performed before and 6 months after angioplasty; renal length, mean cortical thickness (MCT), cortical area (CA), and medullary length (ML) were measured from the axial slices in the 14 contralateral and 14 poststenotic then revascularized kidneys. Blood pressure, creatinine clearance, and number of antihypertensive drugs were analyzed. RESULTS: At 6 months, the systolic blood pressure was significantly reduced (p=0.007), but the number of antihypertensive drugs and the creatinine clearance did not change significantly. Most morphological parameters before and after angioplasty were different in the contralateral versus poststenotic kidneys (renal length, p=0.01; MCT, p=0.01; ML, p=0.03; CA, p=0.008). After angioplasty, there was an 11% drop in cortical atrophy associated with a mean 4-mm increase in medullary length in the poststenotic/revascularized kidneys. The contralateral kidneys exhibited corticomedullary thinning after angioplasty. CONCLUSIONS: In atherosclerotic renal disease, cortical thinning could be a useful timesaving marker to assess the significance of the lesion and to evaluate associated distal lesions. The favorable blood pressure outcome supports the existence of reversible ischemic lesions, particularly in the medulla. Angioplasty appears to be useful for the poststenotic kidney, according to the morphological study.

Adult↗
PubMedDate not supplied

Midterm results of endoluminal stent grafting of the thoracic aorta.

The purpose of this study was to evaluate the overall outcome of repair of thoracic aortic lesions with endoluminal grafts. Patients were studied prospectively following the implantation of a thoracic endovascular device. Preoperative imaging was performed by helical computed tomography (CT), angiography, transesophageal ultrasonography, or magnetic resonance imaging. Procedures were performed in an endovascular surgical suite under general anesthesia. All patients were evaluated with CT and chest radiography at discharge and at 1, 6, and 12 months. From December 1999 to November 2001, thirty-two patients were enrolled in the study (mean age 62 years; 20 male and 12 female patients). Seventeen patients had dissections, five patients had ruptured aortic ulcer, five patients had traumatic ruptures, three patients had atherosclerotic aneurysms, and two patients had pseudoaneurysms. An American Society of Anesthesiology score of III or IV was evaluated in 22 (69%) patients. The procedure was performed under emergency conditions in 11 cases. All prostheses were implanted successfully. There were no conversions. Three patients (9%) presented with a neurologic event following the implantation procedure, which was lethal in one case (hemorrhagic stroke). Two other patients died during early follow-up of myocardial infarction and multiorgan failure. The early death rate was 9%. The mean follow-up was 13.5 months. During follow-up, the maximal diameter of the aorta shrunk (> or = 5 mm) in 9 (28%) patients, remained stable in 17 (53%) patients, and increased (> or = 5 mm) in 6 (19%) patients. All patients presenting with an increased diameter were initially treated for dissections. A type 1 endoleak was diagnosed on the discharge CT scan in one patient. It sealed spontaneously thereafter. A type 3 endoleak was diagnosed 3 months after the procedure in one patient. A complementary stent graft was implanted in two patients presenting with a dissection with persistent patent false lumen and aortic enlargement. Three patients died during follow-up (two aneurysm-related and one aneurysm-unrelated death). The morbidity and mortality rates reported in our series related to the preoperative morbid conditions of the patients treated. Thoracic aorta endografting is an alternative to open surgery in this subset of patients.

Aortic Dissection↗