252 resultados para geometry clean-up


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PURPOSE: To report our results of endovascular aneurysm repair (EVAR) over a 10-year period using systematic preoperative collateral artery embolization. METHODS: From 1999 until 2009, 124 patients (117 men; mean age 70.8 years) with abdominal aortic aneurysm (AAA) underwent embolization of patent lumbar and/or inferior mesenteric arteries prior to elective EVAR procedures. Embolization was systematically attempted and, whenever possible, performed using microcoils and a coaxial technique. Follow-up included computed tomography and/or magnetic resonance imaging and abdominal radiography. RESULTS: The technical success for EVAR was 96% (119/124), with 4 patients dying within 30 days (3.2% perioperative mortality) and 1 type III endoleak accounting for the failures. Collateral arteries were occluded spontaneously or by embolization in 60 (48%) of 124 patients. The endoleak rate was 50.9% (74 in 61 patients), most of which were type II (19%). Over a mean clinical follow-up of 60.5±34.1 months (range 1-144), aneurysm sac dimensions decreased in 66 patients, increased in 19 patients, and were stable in 35. The endoleak rate was significantly higher in the patients with increasing sac diameter (p<0.001). Among the patients with patent collateral arteries, 38/64 (59.3%) developed 46 leaks, while 28 leaks appeared in 23 (41%) of 56 patients with collateral artery occlusion (p=0.069). The type II endoleak rate significantly differed between these two groups (47.8% vs. 3.6%, p<0.001). CONCLUSION: Preoperative collateral embolization seems to be a valid method of reducing the incidence of type II endoleak, improving the long-term outcome.

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OBJECTIVES: This study was designed to compare the long-term clinical outcome of coronary artery bypass grafting (CABG) with intracoronary stenting of patients with isolated proximal left anterior descending coronary artery. BACKGROUND: Although numerous trials have compared coronary angioplasty with bypass surgery, none assessed the clinical evaluation in the long term. METHODS: We evaluated the 10-year clinical outcome in the SIMA (Stent versus Internal Mammary Artery grafting) trial. Patients were randomly assigned to stent implantation versus CABG. RESULTS: Of 123 randomized patients, 59 underwent CABG and 62 received a stent (2 patients were excluded). Follow-up after 10 years was obtained for 98% of the randomized patients. Twenty-six patients (42%) in the percutaneous coronary intervention group and 10 patients (17%) in the CABG group reached an end point (p < 0.001). This difference was due to a higher need for additional revascularization. The incidences of death and myocardial infarction were identical at 10%. Progression of the disease requiring additional revascularization was rare (5%) and was similar for the 2 groups. Stent thrombosis occurred in 2 patients (3%). Angina functional class showed no significant differences between the 2 groups. CONCLUSIONS: Both stent implantation and CABG are safe and highly effective in relieving symptoms in patients with isolated, proximal left anterior descending coronary artery stenosis. Stenting with bare-metal stents is associated with a higher need for repeat interventions. The long-term prognosis for these patients is excellent with either mode of revascularization.

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OBJECT: The aim of this study was to evaluate the long-term safety and efficacy of bilateral contemporaneous deep brain stimulation (DBS) in patients who have levodopa-responsive parkinsonism with untreatable motor fluctuations. Bilateral pallidotomy carries a high risk of corticobulbar and cognitive dysfunction. Deep brain stimulation offers new alternatives with major advantages such as reversibility of effects, minimal permanent lesions, and adaptability to individual needs, changes in medication, side effects, and evolution of the disease. METHODS: Patients in whom levodopa-responsive parkinsonism with untreatable severe motor fluctuations has been clinically diagnosed underwent bilateral pallidal magnetic resonance image-guided electrode implantation while receiving a local anesthetic. Pre- and postoperative evaluations at 3-month intervals included Unified Parkinson's Disease Rating Scale (UPDRS) scoring, Hoehn and Yahr staging, 24-hour self-assessments, and neuropsychological examinations. Six patients with a mean age of 55 years (mean 42-67 years), a mean duration of disease of 15.5 years (range 12-21 years), a mean "on/off' Hoehn and Yahr stage score of 3/4.2 (range 3-5), and a mean "off' time of 40% (range 20-50%) underwent bilateral contemporaneous pallidal DBS, with a minimum follow-up period lasting 24 months (range 24-30 months). The mean dose of levodopa in these patients could not be changed significantly after the procedure and pergolide was added after 12 months in five patients because of recurring fluctuations despite adjustments in stimulation parameters. All but two patients had no fluctuations until 9 months. Two of the patients reported barely perceptible fluctuations at 12 months and two at 15 months; however, two patients remain without fluctuations at 2 years. The mean improvements in the UPDRS motor score in the off time and the activities of daily living (ADL) score were more than 50%; the mean off time decreased from 40 to 10%, and the mean dyskinesia and complication of treatment scores were reduced to one-third until pergolide was introduced at 12 months. No significant improvement in "on" scores was observed. A slight worsening after 1 year was observed and three patients developed levodopa- and stimulation-resistant gait ignition failure and minimal fluctuations at 1 year. Side effects, which were controlled by modulation of stimulation, included dysarthria, dystonia, and confusion. CONCLUSIONS: Bilateral pallidal DBS is safe and efficient in patients who have levodopa-responsive parkinsonism with severe fluctuations. Major improvements in motor score, ADL score, and off time persisted beyond 2 years after the operation, but signs of decreased efficacy started to be seen after 12 months.

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Paraganglioma of the heart are potentially invasive, highly vascularized tumors for which complete resection may be curative. Derived from the cardiac wall in most instances, resectability can be assessed after integration of the data provided by MRI in T2 sequence, and coronarography. A fully documented case of a large cardiac pheochromocytoma of the left atrium and AV groove is reported and the pertinent literature on the subject is here presented.

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PURPOSE: To determine whether motion preservation following oblique cervical corpectomy (OCC) for cervical spondylotic myelopathy (CSM) persists with serial follow-up. METHODS: We included 28 patients with preoperative and at least two serial follow-up neutral and dynamic cervical spine radiographs who underwent OCC for CSM. Patients with an ossified posterior longitudinal ligament (OPLL) were excluded. Changes in sagittal curvature, segmental and whole spine range of motion (ROM) were measured. Nathan's system graded anterior osteophyte formation. Neurological function was measured by Nurick's grade and modified Japanese Orthopedic Association (JOA) scores. RESULTS: The majority (23 patients) had a single or 2-level corpectomy. The average duration of follow-up was 45 months. The Nurick's grade and the JOA scores showed statistically significant improvements after surgery (p < 0.001). 17% of patients with preoperative lordotic spines had a loss of lordosis at last follow-up, but with no clinical worsening. 77% of the whole spine ROM and 62% of segmental ROM was preserved at last follow-up. The whole spine and segmental ROM decreased by 11.2° and 10.9°, respectively (p ≤ 0.001). Patients with a greater range of segmental movement preoperatively had a statistically greater range of movement at follow-up. The analysis of serial radiographs indicated that the range of movement of the whole spine and the range of movement at the segmental spine levels significantly reduced during the follow-up period. Nathan's grade showed increase in osteophytosis in more than two-thirds of the patients (p ≤ 0.01). The whole spine range of movement at follow-up significantly correlated with Nathan's grade. CONCLUSIONS: Although the OCC preserves segmental and whole spine ROM, serial measurements show a progressive decrease in ROM albeit without clinical worsening. The reduction in this ROM is probably related to degenerative ossification of spinal ligaments.

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Changes in the rate of growth and adiposity index (Quetelet index), calculated as weight/(length)2, kg/m2, were monitored from birth to 3 years in 19 premature babies (post-conceptional age 31.2 +/- 2 weeks) who were subjected during rapid growth (16 +/- 4 g/kg.day) to initial metabolic balance studies in the first weeks of life. These studies showed that the rate of fat accretion in these infants (3.3 +/- 0.9 g/kg.day) was substantially greater than that observed in fetuses of the same gestational age (2 g/kg.day) but the adiposity index was lower (9.6 +/- 1 kg/m2) than intrauterine values (11 kg/m2). Since at 6 months of age (corrected for gestational age at birth) the adiposity index was close to normality (103% of standard), the greater rate of fat accretion in early life contributed to progressively restore total body fat in premature babies. It is concluded that despite substantial fat deposition during the first weeks of life, the future evolution of these premature babies is favourable as judged from the normalization of adiposity index within the first 2 years of life.

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By using an in vitro model of antibody-mediated demyelination, we investigated the relationship between tumor necrosis factor-alpha (TNF-alpha) and heat shock protein (HSP) induction with respect to oligodendrocyte survival. Differentiated aggregate cultures of rat telencephalon were subjected to demyelination by exposure to antibodies against myelin oligodendrocyte glycoprotein (MOG) and complement. Cultures were analyzed 48 hr after exposure. Myelin basic protein (MBP) expression was greatly decreased, but no evidence was found for either necrosis or apoptosis. TNF-alpha was significantly up-regulated. It was localized predominantly in neurons and to a lesser extent in astrocytes and oligodendrocytes, and it was not detectable in microglial cells. Among the different HSPs examined, HSP32 and alphaB-crystallin were up-regulated; they may confer protection from oxidative stress and from apoptotic death, respectively. These results suggest that TNF-alpha, often regarded as a promoter of oligodendroglial death, could alternatively mediate a protective pathway through alphaB-crystallin up-regulation.

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Deeply incised river networks are generally regarded as robust features that are not easily modified by erosion or tectonics. Although the reorganization of deeply incised drainage systems has been documented, the corresponding importance with regard to the overall landscape evolution of mountain ranges and the factors that permit such reorganizations are poorly understood. To address this problem, we have explored the rapid drainage reorganization that affected the Cahabon River in Guatemala during the Quaternary. Sediment-provenance analysis, field mapping, and electrical resistivity tomography (ERT) imaging are used to reconstruct the geometry of the valley before the river was captured. Dating of the abandoned valley sediments by the Be-10-Al-26 burial method and geomagnetic polarity analysis allow us to determine the age of the capture events and then to quantify several processes, such as the rate of tectonic deformation of the paleovalley, the rate of propagation of post-capture drainage reversal, and the rate at which canyons that formed at the capture sites have propagated along the paleovalley. Transtensional faulting started 1 to 3 million years ago, produced ground tilting and ground faulting along the Cahabon River, and thus generated differential uplift rate of 0.3 +/- 0.1 up to 0.7 +/- 0.4 mm . y(-1) along the river's course. The river responded to faulting by incising the areas of relative uplift and depositing a few tens of meters of sediment above the areas of relative subsidence. Then, the river experienced two captures and one avulsion between 700 ky and 100 ky. The captures breached high-standing ridges that separate the Cahabon River from its captors. Captures occurred at specific points where ridges are made permeable by fault damage zones and/or soluble rocks. Groundwater flow from the Cahabon River down to its captors likely increased the erosive power of the captors thus promoting focused erosion of the ridges. Valley-fill formation and capture occurred in close temporal succession, suggesting a genetic link between the two. We suggest that the aquifers accumulated within the valley-fills, increased the head along the subterraneous system connecting the Cahabon River to its captors, and promoted their development. Upon capture, the breached valley experienced widespread drainage reversal toward the capture sites. We attribute the generalized reversal to combined effects of groundwater sapping in the valley-fill, axial drainage obstruction by lateral fans, and tectonic tilting. Drainage reversal increased the size of the captured areas by a factor of 4 to 6. At the capture sites, 500 m deep canyons have been incised into the bedrock and are propagating upstream at a rate of 3 to 11 mm . y(-1) deepening at a rate of 0.7 to 1 5 mm . y(-1). At this rate, 1 to 2 million years will be necessary for headward erosion to completely erase the topographic expression of the paleovalley. It is concluded that the rapid reorganization of this drainage system was made possible by the way the river adjusted to the new tectonic strain field, which involved transient sedimentation along the river's course. If the river had escaped its early reorganization and had been given the time necessary to reach a new dynamic equilibrium, then the transient conditions that promoted capture would have vanished and its vulnerability to capture would have been strongly reduced.

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BACKGROUND: Microvascular decompression (MVD) is the reference technique for pharmacoresistant trigeminal neuralgia (TN). OBJECTIVE: To establish whether the safety and efficacy of Gamma Knife surgery for recurrent TN are influenced by prior MVD. METHODS: Between July 1992 and November 2010, 54 of 737 patients (45 of 497 with >1 year of follow-up) had a history of MVD (approximately half also with previous ablative procedure) and were operated on with Gamma Knife surgery for TN in the Timone University Hospital. A single 4-mm isocenter was positioned in the cisternal portion of the trigeminal nerve at a median distance of 7.6 mm (range, 3.9-11.9 mm) anterior to the emergence of the nerve. A median maximum dose of 85 Gy (range, 70-90 Gy) was delivered. RESULTS: The median follow-up time was 39.5 months (range, 14.1-144.6 months). Thirty-five patients (77.8%) were initially pain free in a median time of 14 days (range, 0-180 days), much lower compared with our global population of classic TN (P = .01). Their actuarial probabilities of remaining pain-free without medication at 3, 5, 7, and 10 years were 66.5%, 59.1%, 59.1%, and 44.3%. The hypoesthesia actuarial rate at 1 year was 9.1% and remained stable until 12 years (median, 8 months). CONCLUSION: Patients with previous MVD showed a significantly lower probability of initial pain cessation compared with our global population with classic TN (P = .01). The toxicity was low (only 9.1% hypoesthesia); furthermore, no patient reported bothersome hypoesthesia. However, the probability of maintaining pain relief without medication was 44.3% at 10 years, similar to our global series of classic TN (P = .85). ABBREVIATIONS: BNI, Barrow Neurological InstituteCI, confidence intervalCTN, classic trigeminal neuralgiaGKS, Gamma Knife surgeryHR, hazard ratioMVD, microvascular decompressionTN, trigeminal neuralgia.

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OBJECTIVE: The objective of this trial was to assess which type of warm-up has the highest effect on virtual reality (VR) laparoscopy performance. The following warm-up strategies were applied: a hands-on exercise (group 1), a cognitive exercise (group 2), and no warm-up (control, group 3). DESIGN: This is a 3-arm randomized controlled trial. SETTING: The trial was conducted at the department of surgery of the University Hospital Basel in Switzerland. PARTICIPANTS: A total of 94 participants, all laypersons without any surgical or VR experience, completed the study. RESULTS: A total of 96 participants were randomized, 31 to group 1, 31 to group 2, and 32 to group 3. There were 2 postrandomization exclusions. In the multivariate analysis, we found no evidence that the intervention had an effect on VR performance as represented by 6 calculated subscores of accuracy, time, and path length for (1) camera manipulation and (2) hand-eye coordination combined with 2-handed maneuvers (p = 0.795). Neither the comparison of the average of the intervention groups (groups 1 and 2) vs control (group 3) nor the pairwise comparisons revealed any significant differences in VR performance, neither multivariate nor univariate. VR performance improved with increasing performance score in the cognitive exercise warm-up (iPad 3D puzzle) for accuracy, time, and path length in the camera navigation task. CONCLUSIONS: We were unable to show an effect of the 2 tested warm-up strategies on VR performance in laypersons. We are currently designing a follow-up study including surgeons rather than laypersons with a longer warm-up exercise, which is more closely related to the final task.

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INTRODUCTION AND HYPOTHESIS: The objective of this study is to assess anatomical and functional results of the extraperitoneal uterosacral ligament suspension (USL) in women with post-hysterectomy vaginal vault prolapse. METHODS: One hundred and twenty-three consecutive women were included. Concurrent procedures were anterior colporraphy with fascial repair (20%) and mesh reinforcement (49%), posterior colporraphy with fascial repair (38%) and mesh reinforcement (56%) and a sling procedure (29%). Women were assessed using Baden and Walker and pelvic organ prolapse quantification classification pre- and post-operatively. RESULTS: One hundred and ten patients (89%) were available for follow-up. Mean follow-up was 2 years. Objective success rate regarding the vaginal cuff is 95.4%. Global anatomical success rate was 85.5%. Urinary, coital and bowel symptoms were improved following surgery. Mesh exposure rate was 19.3%, with all cases managed conservatively or with minor interventions. CONCLUSION: Bilateral extraperitoneal USL is an effective operation to restore apical support with low morbidity, which avoids potential risks associated with opening the peritoneal cavity.