Reorganização do Controlo Postural no Acidente Vascular Encefálico: Ajustes Posturais Antecipatórios e Stiffness da Tibiotársica

Introdução: A reorganização do Sistema Nervoso após Acidente Vascular Encefálico é dependente da experienciação de diferentes tipos de input no âmbito da intervenção em fisioterapia. A potenciação do controlo postural (CP) nestes sujeitos é importante para organização dos ajustes posturais antecipatórios nas tarefas funcionais levantar, sentar e início da marcha e pode ser acompanhado de uma regulação do stiffness. Objectivo(s): Reportar as modificações ocorridas nos tempos de inibição e ativação dos músculos solear e tibial anterior, respetivamente, nas sequências de movimento levantar, sentar e início da marcha, na linha temporal atribuída aos APA’s assim como descrever as modificações ocorridas no comportamento do stiffness passivo da tibiotársica. Métodos: Foi implementado um programa de fisioterapia durante 3 meses em 5 participantes com Acidente Vascular Encefálico. Estes foram avaliados previamente à implementação do programa e após (M0 e M1). Foi analisada a atividade eletromiográfica dos músculos solear e tibial anterior, em ambos os membros inferiores, na linha temporal atribuída aos APA’s nas referidas tarefas. O torque e a amplitude articular da tibiotársica foi monitorizada, através do dinamómetro isocinético, no movimento passivo de dorsiflexão, e registada a atividade muscular através de eletromiografia de superfície, nos músculos solear e gastrocnémio medial. Resultados: À exceção do músculo tibial anterior contralesional no paciente C, todos os participantes demonstraram modificações nos tempos dos músculos do membro contralesional na tarefa levantar. No membro ispsilesional todos os participantes demonstraram alterações, sem que seja possível definir uma tendência. Todos apresentaram uma diminuição do stiffness, embora nos participantes A e E mais evidente nas amplitudes intermédias. Conclusão: Entre os dois momentos de avaliação foi possível reportar modificações nos tempos de inibição dos músculos solear e nos tempos de ativação dos músculos tibial anterior na linha temporal atribuída aos APA’s, no entanto mais homogéneas no membro contralesional na tarefa levantar. Em todos os participantes o stiffness sofreu alterações no sentido da diminuição.

Iatrogenic Aortic Pseudoaneurysm: a Forgotten Complication

Pseudoaneurysms of the ascending aorta are a rare complication of cardiac surgery. However, the poor prognosis associated with this condition if untreated makes early diagnosis and treatment important. We present the case of a 66-year-old woman who had undergone mitral valvuloplasty 12 days previously, who was admitted with a diagnosis of new-onset atrial fibrillation. The transthoracic echocardiogram showed a clot in the right atrium and anticoagulation was initiated, followed by antibiotic therapy. After further investigation, the patient was diagnosed with a pseudoaneurysm of the ascending aorta and underwent surgical repair, followed by six weeks of antibiotic therapy. She was readmitted six months later for an abscess of the lower sternum and mediastinum. After a conservative approach with antibiotics and local drainage failed, recurrence of a large pseudoaneurysm compressing the superior vena cava was documented. A third operation was performed to debride the infected tissue and to place an aortic allograft. There were no postoperative complications.

Lower Atherosclerotic Burden in Familial Abdominal Aortic Aneurysm

OBJECTIVE: Despite the apparent familial tendency toward abdominal aortic aneurysm (AAA) formation, the genetic causes and underlying molecular mechanisms are still undefined. In this study, we investigated the association between familial AAA (fAAA) and atherosclerosis. METHODS: Data were collected from a prospective database including AAA patients between 2004 and 2012 in the Erasmus University Medical Center, Rotterdam, The Netherlands. Family history was obtained by written questionnaire (93.1% response rate). Patients were classified as fAAA when at least one affected first-degree relative with an aortic aneurysm was reported. Patients without an affected first-degree relative were classified as sporadic AAA (spAAA). A standardized ultrasound measurement of the common carotid intima-media thickness (CIMT), a marker for generalized atherosclerosis, was routinely performed and patients' clinical characteristics (demographics, aneurysm characteristics, cardiovascular comorbidities and risk factors, and medication use) were recorded. Multivariable linear regression analyses were used to assess the mean adjusted difference in CIMT and multivariable logistic regression analysis was used to calculate associations of increased CIMT and clinical characteristics between fAAA and spAAA. RESULTS: A total of 461 AAA patients (85% men, mean age, 70 years) were included in the study; 103 patients (22.3%) were classified as fAAA and 358 patients (77.7%) as spAAA. The mean (standard deviation) CIMT in patients with fAAA was 0.89 (0.24) mm and 1.00 (0.29) mm in patients with spAAA (P = .001). Adjustment for clinical characteristics showed a mean difference in CIMT of 0.09 mm (95% confidence interval, 0.02-0.15; P = .011) between both groups. Increased CIMT, smoking, hypertension, and diabetes mellitus were all less associated with fAAA compared with spAAA. CONCLUSIONS: The current study shows a lower atherosclerotic burden, as reflected by a lower CIMT, in patients with fAAA compared with patients with spAAA, independent of common atherosclerotic risk factors. These results support the hypothesis that although atherosclerosis is a common underlying feature in patients with aneurysms, atherosclerosis is not the primary driving factor in the development of fAAA.

Familial Abdominal Aortic Aneurysm Is Associated With More Complications After Endovascular Aneurysm Repair

OBJECTIVE: A familial predisposition to abdominal aortic aneurysms (AAAs) is present in approximately one-fifth of patients. Nevertheless, the clinical implications of a positive family history are not known. We investigated the risk of aneurysm-related complications after endovascular aneurysm repair (EVAR) for patients with and without a positive family history of AAA. METHODS: Patients treated with EVAR for intact AAAs in the Erasmus University Medical Center between 2000 and 2012 were included in the study. Family history was obtained by written questionnaire. Familial AAA (fAAA) was defined as patients having at least one first-degree relative affected with aortic aneurysm. The remaining patients were considered sporadic AAA. Cardiovascular risk factors, aneurysm morphology (aneurysm neck, aneurysm sac, and iliac measurements), and follow-up were obtained prospectively. The primary end point was complications after EVAR, a composite of endoleaks, need for secondary interventions, aneurysm sac growth, acute limb ischemia, and postimplantation rupture. Secondary end points were specific components of the primary end point (presence of endoleak, need for secondary intervention, and aneurysm sac growth), aneurysm neck growth, and overall survival. Kaplan-Meier estimates for the primary end point were calculated and compared using log-rank (Mantel-Cox) test of equality. A Cox-regression model was used to calculate the independent risk of complications associated with fAAA. RESULTS: A total of 255 patients were included in the study (88.6% men; age 72 ± 7 years, median follow-up 3.3 years; interquartile range, 2.2-6.1). A total of 51 patients (20.0%) were classified as fAAA. Patients with fAAA were younger (69 vs 72 years; P = .015) and were less likely to have ever smoked (58.8% vs 73.5%; P = .039). Preoperative aneurysm morphology was similar in both groups. Patients with fAAA had significantly more complications after EVAR (35.3% vs 19.1%; P = .013), with a twofold increased risk (adjusted hazard ratio, 2.1; 95% confidence interval, 1.2-3.7). Secondary interventions (39.2% vs 20.1%; P = .004) and aneurysm sac growth (20.8% vs 9.5%; P = .030) were the most important elements accounting for the difference. Furthermore, a trend toward more type I endoleaks during follow-up was observed (15.6% vs 7.4%; P = .063) and no difference in overall survival. CONCLUSIONS: The current study shows that patients with a familial form of AAA develop more aneurysm-related complications after EVAR, despite similar AAA morphology at baseline. These findings suggest that patients with fAAA form a specific subpopulation and create awareness for a possible increase in the risk of complications after EVAR.

Early Sac Shrinkage Predicts a Low Risk of Late Complications After Endovascular Aortic Aneurysm Repair

BACKGROUND: Aneurysm shrinkage has been proposed as a marker of successful endovascular aneurysm repair (EVAR). Patients with early postoperative shrinkage may experience fewer subsequent complications, and consequently require less intensive surveillance. METHODS: Patients undergoing EVAR from 2000 to 2011 at three vascular centres (in 2 countries), who had two imaging examinations (postoperative and after 6-18 months), were included. Maximum diameter, complications and secondary interventions during follow-up were registered. Patients were categorized according to early sac dynamics. The primary endpoint was freedom from late complications. Secondary endpoints were freedom from secondary intervention, postimplant rupture and direct (type I/III) endoleaks. RESULTS: Some 597 EVARs (71.1 per cent of all EVARs) were included. No shrinkage was observed in 284 patients (47.6 per cent), moderate shrinkage (5-9 mm) in 142 (23.8 per cent) and major shrinkage (at least 10 mm) in 171 patients (28.6 per cent). Four years after the index imaging, the rate of freedom from complications was 84.3 (95 per cent confidence interval 78.7 to 89.8), 88.1 (80.6 to 95.5) and 94.4 (90.1 to 98.7) per cent respectively. No shrinkage was an independent risk factor for late complications compared with major shrinkage (hazard ratio (HR) 3.11; P < 0.001). Moderate compared with major shrinkage (HR 2.10; P = 0.022), early postoperative complications (HR 3.34; P < 0.001) and increasing abdominal aortic aneurysm baseline diameter (HR 1.02; P = 0.001) were also risk factors for late complications. Freedom from secondary interventions and direct endoleaks was greater for patients with major sac shrinkage. CONCLUSION: Early change in aneurysm sac diameter is a strong predictor of late complications after EVAR. Patients with major sac shrinkage have a very low risk of complications for up to 5 years. This parameter may be used to tailor postoperative surveillance.

Clinical Outcome and Morphologic Determinants of Mural Thrombus in Abdominal Aortic Endografts

OBJECTIVE:Endograft mural thrombus has been associated with stent graft or limb thrombosis after endovascular aneurysm repair (EVAR). This study aimed to identify clinical and morphologic determinants of endograft mural thrombus accumulation and its influence on thromboembolic events after EVAR. METHODS: A prospectively maintained database of patients treated by EVAR at a tertiary institution from 2000 to 2012 was analyzed. Patients treated for degenerative infrarenal abdominal aortic aneurysms and with available imaging for thrombus analysis were considered. All measurements were performed on three-dimensional center-lumen line computed tomography angiography (CTA) reconstructions. Patients with thrombus accumulation within the endograft's main body with a thickness >2 mm and an extension >25% of the main body's circumference were included in the study group and compared with a control group that included all remaining patients. Clinical and morphologic variables were assessed for association with significant thrombus accumulation within the endograft's main body by multivariate regression analysis. Estimates for freedom from thromboembolic events were obtained by Kaplan-Meier plots. RESULTS: Sixty-eight patients (16.4%) presented with endograft mural thrombus. Median follow-up time was 3.54 years (interquartile range, 1.99-5.47 years). In-graft mural thrombus was identified on 30-day CTA in 22 patients (32.4% of the study group), on 6-month CTA in 8 patients (11.8%), and on 1-year CTA in 17 patients (25%). Intraprosthetic thrombus progressively accumulated during the study period in 40 patients of the study group (55.8%). Overall, 17 patients (4.1%) presented with endograft or limb occlusions, 3 (4.4%) in the thrombus group and 14 (4.1%) in the control group (P = .89). Thirty-one patients (7.5%) received an aortouni-iliac (AUI) endograft. Two endograft occlusions were identified among AUI devices (6.5%; overall, 0.5%). None of these patients showed thrombotic deposits in the main body, nor were any outflow abnormalities identified on the immediately preceding CTA. Estimated freedom from thromboembolic events at 5 years was 95% in both groups (P = .97). Endograft thrombus accumulation was associated with >25% proximal aneurysm neck thrombus coverage at baseline (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1-3.3), neck length ≤ 15 mm (OR, 2.4; 95% CI, 1.3-4.2), proximal neck diameter ≥ 30 mm (OR, 2.4; 95% CI, 1.3-4.6), AUI (OR, 2.2; 95% CI, 1.8-5.5), or polyester-covered stent grafts (OR, 4.0; 95% CI, 2.2-7.3) and with main component "barrel-like" configuration (OR, 6.9; 95% CI, 1.7-28.3). CONCLUSIONS: Mural thrombus formation within the main body of the endograft is related to different endograft configurations, main body geometry, and device fabric but appears to have no association with the occurrence of thromboembolic events over time.

Aortic and Tricuspid Endocarditis in Hemodialysis Patient with Systemic and Pulmonary Embolism

This is a case report of a 43-year-old Caucasian male with end-stage renal disease being treated with hemodialysis and infective endocarditis in the aortic and tricuspid valves. The clinical presentation was dominated by neurologic impairment with cerebral embolism and hemorrhagic components. A thoracoabdominal computerized tomography scan revealed septic pulmonary embolus. The patient underwent empirical antibiotherapy with ceftriaxone, gentamicin and vancomycin, and the therapy was changed to flucloxacilin and gentamicin after the isolation of S. aureus in blood cultures. The multidisciplinary team determined that the patient should undergo valve replacement after the stabilization of the intracranial hemorrhage; however, on the 8th day of hospitalization, the patient entered cardiac arrest due to a massive septic pulmonary embolism and died. Despite the risk of aggravation of the hemorrhagic cerebral lesion, early surgical intervention should be considered in high-risk patients.

Low Socioeconomic Status is an Independent Risk Factor for Survival After Abdominal Aortic Aneurysm Repair and Open Surgery for Peripheral Artery Disease

OBJECTIVE/BACKGROUND: The association between socioeconomic status (SES), presentation, and outcome after vascular surgery is largely unknown. This study aimed to determine the influence of SES on post-operative survival and severity of disease at presentation among vascular surgery patients in the Dutch setting of equal access to and provision of care. METHODS: Patients undergoing surgical treatment for peripheral artery disease (PAD), abdominal aortic aneurysm (AAA), or carotid artery stenosis between January 2003 and December 2011 were retrospectively included. The association between SES, quantified by household income, disease severity at presentation, and survival was studied using logistic and Cox regression analysis adjusted for demographics, and medical and behavioral risk factors. RESULTS: A total of 1,178 patients were included. Low income was associated with worse post-operative survival in the PAD cohort (n = 324, hazard ratio 1.05, 95% confidence interval [CI] 1.00-1.10, per 5,000 Euro decrease) and the AAA cohort (n = 440, quadratic relation, p = .01). AAA patients in the lowest income quartile were more likely to present with a ruptured aneurysm (odds ratio [OR] 2.12, 95% CI 1.08-4.17). Lowest income quartile PAD patients presented more frequently with symptoms of critical limb ischemia, although no significant association could be established (OR 2.02, 95% CI 0.96-4.26). CONCLUSIONS: The increased health hazards observed in this study are caused by patient related factors rather than differences in medical care, considering the equality of care provided by the study setting. Although the exact mechanism driving the association between SES and worse outcome remains elusive, consideration of SES as a risk factor in pre-operative decision making and focus on treatment of known SES related behavioral and psychosocial risk factors may improve the outcome of patients with vascular disease.

Acute Upper Limb Ischemia, a Rare Presentation of Giant Cell Arteritis

Giant cell arteritis (GCA) is a systemic large vessel vasculitis, with extracranial arterial involvement described in 10-15% of cases, usually affecting the aorta and its branches. Patients with GCA are more likely to develop aortic aneurysms, but these are rarely present at the time of the diagnosis. We report the case of an 80-year-old Caucasian woman, who reported proximal muscle pain in the arms with morning stiffness of the shoulders for eight months. In the previous two months, she had developed worsening bilateral arm claudication, severe pain, cold extremities and digital necrosis. She had no palpable radial pulses and no measurable blood pressure. The patient had normochromic anemia, erythrocyte sedimentation rate of 120 mm/h, and a negative infectious and autoimmune workup. Computed tomography angiography revealed concentric wall thickening of the aorta extending to the aortic arch branches, particularly the subclavian and axillary arteries, which were severely stenotic, with areas of bilateral occlusion and an aneurysm of the ascending aorta (47 mm). Despite corticosteroid therapy there was progression to acute critical ischemia. She accordingly underwent surgical revascularization using a bilateral carotid-humeral bypass. After surgery, corticosteroid therapy was maintained and at six-month follow-up she was clinically stable with reduced inflammatory markers. GCA, usually a chronic benign vasculitis, presented exceptionally in this case as acute critical upper limb ischemia, resulting from a massive inflammatory process of the subclavian and axillary arteries, treated with salvage surgical revascularization.

Dynamic stiffness of the piled foundation of a onshore wind turbine

One of today's biggest concerns is the increase of energetic needs, especially in the developed countries. Among various clean energies, wind energy is one of the technologies that assume greater importance on the sustainable development of humanity. Despite wind turbines had been developed and studied over the years, there are phenomena that haven't been yet fully understood. This work studies the soil-structure interaction that occurs on a wind turbine's foundation composed by a group of piles that is under dynamic loads caused by wind. This problem assumes special importance when the foundation is implemented on locations where safety criteria are very demanding, like the case of a foundation mounted on a dike. To the phenomenon of interaction between two piles and the soil between them it's given the name of pile-soil-pile interaction. It is known that such behavior is frequency dependent, and therefore, on this work evaluation of relevant frequencies for the intended analysis is held. During the development of this thesis, two methods were selected in order to assess pile-soil-pile interaction, being one of analytical nature and the other of numerical origin. The analytical solution was recently developed and its called Generalized pile-soil-pile theory, while for the numerical method the commercial nite element software PLAXIS 3D was used. A study of applicability of the numerical method is also done comparing the given solution by the nite element methods with a rigorous solution widely accepted by the majority of the authors.

Screening for abdominal aortic aneurysms

OBJECTIVE AND METHODS: Screening for abdominal aortic aneurysms may be useful to decrease mortality related to rupture. We conducted a study to assess the prevalence of abdominal aortic aneurysms in southern Brazil and to define risk factors associated with high prevalence of this disorder. The screening was conducted using abdominal ultrasound. Three groups were studied: Group 1 - cardiology clinic patients; Group 2 - individuals with severe ischemic disease and previous coronary surgery, or important lesions on cardiac catheterism; Group 3 - individuals without cardiac disease selected from the general population. All individuals were male and older than 54 years of age. The ultrasonographic diagnosis of aneurysm was based on an anteroposterior abdominal aorta diameter of 3 cm, or on an abdominal aorta diameter 0.5 cm greater than that of the supra-renal aorta. RESULTS: A total of 2.281 people were screened for abdominal aortic aneurysms in all groups: Group 1 - 768 individuals, Group 2 - 501 individuals, and Group 3 - 1012 individuals. The prevalence of aneurysms was 4.3%, 6.8% and 1.7%, respectively. Age and cigarette smoking were significantly associated with increased prevalence of aneurysms, as was the diagnosis of peripheral artery disease. DISCUSSION: We concluded that screening may be an important tool to prevent the mortality associated with abdominal aortic aneurysms surgery. Additionally, the cost of screening can be decreased if only individuals presenting significant risk factors, such as coronary and peripheral artery disease, smokers and relatives of aneurysm patients, are examined.

Monitoring the early stiffness development in epoxy adhesives for structural strengthening

The present work aimed to assess the early-age evolution of E-modulus of epoxy adhesives used for Fibre-Reinforced Polymer (FRP) strengthening applications. The study involved adapting an existing technique devised for continuous monitoring of concrete stiffness since casting, called EMM-ARM (Elasticity Modulus Measurement through Ambient Response Method) for evaluation of epoxy stiffness. Furthermore, monotonic tensile tests according to ISO standards and cyclic tensile tests were carried out at several ages. A comparison between the obtained results was performed in order to better understand the performance of the several techniques in the assessment of stiffness of epoxy resins. When compared to the other methodologies, the method for calculation of E-modulus recommended by ISO standard led to lower values, since in the considered strain interval, the adhesive had a non-linear stress–strain relationship. The EMM-ARM technique revealed its capability in clearly identifying the hardening kinetics of epoxy adhesives, measuring the material stiffness growth during the entire curing period. At very early ages the values of Young׳s modulus obtained with quasi-static tests were lower than the values collected by EMM-ARM, due to the fact that epoxy resin exhibited a significant visco-elastic behaviour.

In-plane stiffness of timber floors strengthened with CLT

Five full-scale timber floors were tested in order to analyse the in-plane behaviour of these structural systems. The main objective was an assessment of the effectiveness of in-plane strengthening using cross-laminated timber (CLT). To this end, one unstrengthened specimen (original), one specimen strengthened with a second layer of floorboards, two specimens strengthened with three CLT panels, and one specimen strengthened with two CLT panels, were tested. A numerical analysis was then performed in order to analyse the composite behaviour of the timber floors in more detail. Due to its importance as regards composite behaviour, the first phase of the experimental programme was composed of push-out tests on specimens representing the shear connection between the timber beams and the CLT panels. This paper describes the tests performed and the numerical modelling applied to evaluate the composite behaviour of the strengthened timber floors. The use of CLT panels is revealed to be an effective way to increase the in-plane stiffness of timber floors, through which the behaviour of the composite structure can be significantly changed, depending on the connection applied, or modified as required.

Vanishing spin stiffness in the spin-1/2 Heisenberg chain for any nonzero temperature

Whether at the zero spin density m = 0 and finite temperatures T > 0 the spin stiffness of the spin-1/2 XXX chain is finite or vanishes remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we explicitly compute the stiffness at m = 0 and find strong evidence that it vanishes. In particular, we derive an upper bound on the stiffness within a canonical ensemble at any fixed value of spin density m that is proportional to m2L in the thermodynamic limit of chain length L → ∞, for any finite, nonzero temperature, which implies the absence of ballistic transport for T > 0 for m = 0. Although our method relies in part on the thermodynamic Bethe ansatz (TBA), it does not evaluate the stiffness through the second derivative of the TBA energy eigenvalues relative to a uniform vector potential. Moreover, we provide strong evidence that in the thermodynamic limit the upper bounds on the spin current and stiffness used in our derivation remain valid under string deviations. Our results also provide strong evidence that in the thermodynamic limit the TBA method used by X. Zotos [Phys. Rev. Lett. 82, 1764 (1999)] leads to the exact stiffness values at finite temperature T > 0 for models whose stiffness is finite at T = 0, similar to the spin stiffness of the spin-1/2 Heisenberg chain but unlike the charge stiffness of the half-filled 1D Hubbard model.