The relationships between spinal amplitude of movement, pain and disability in low back pain: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: The role of spinal movement alterations in low back pain (LBP) remains unclear. This systematic review and meta-analyses examined the relationships between spinal amplitude of movement, disability and pain intensity in patients with LBP. DATABASES AND DATA TREATMENT: We searched PubMed, CINAHL, Embase, Pedro and Web of Science for relevant articles until 14th March 2023. Risk of bias was assessed with the Quality in Prognostic Studies Tool. We analysed the relationships between amplitude of movement, disability and pain intensity with standard correlational meta-analyses and meta-analytic structural equation modelling (MASEM) in cross-sectional and longitudinal data. RESULTS: A total of 106 studies (9001 participants) were included. In cross-sectional data, larger amplitude of movement was associated with lower disability (pooled coefficient: -0.25, 95% confidence interval: [-0.29 to -0.21]; 69/5899 studies/participants) and pain intensity (-0.13, [-0.17 to -0.09]; 74/5806). An increase in amplitude of movement was associated with a decrease in disability (-0.23, [-0.31 to -0.15]; 33/2437) and pain intensity (-0.25, [-0.33 to -0.17]; 38/2172) in longitudinal data. MASEM revealed similar results and, in addition, showed that amplitude of movement had a very small influence on the pain intensity-disability relationship. CONCLUSIONS: These results showed a significant but small association between amplitude of movement and disability or pain intensity. Moreover, they demonstrated a direct association between an increase in amplitude of movement and a decrease in pain intensity or disability, supporting interventions aiming to reduce protective spinal movements in patients with LBP. SIGNIFICANCE: The large meta-analyses performed in this work revealed an association between reductions in spinal amplitude of movement and increased levels of disability and pain intensity in people with LBP. Moreover, it highlighted that LBP recovery is associated with a reduction in protective motor behaviour (increased amplitude of movement), supporting the inclusion of spinal movement in the biopsychosocial understanding and management of LBP.

Pasture brome and perennial ryegrass characteristics that influence ewe lamb dietary preference during different seasons and periods of the day.

Under the current scenario for climate change, Bromus valdivianus Phil. (Bv), a drought-resistant species, is an option to complement Lolium perenne L. (Lp) in temperate pastures. However, little is known about animal preference for Bv. A randomised complete block design was used to study ewe lamb's preference between Lp and Bv during morning and afternoon grazing sessions in winter, spring, and summer by assessing the animal behaviour and pasture morphological and chemical attributes. Ewe lambs showed a higher preference for Lp in the afternoon in winter (P < 0.05) and summer (P < 0.01), while no differences were found in spring (P > 0.05). In winter, Bv, relative to Lp, had both greater ADF and NDF (P < 0.001), and lower pasture height (P < 0.01) which negatively affected its preference. The lack of differences in spring were due to an increase in ADF concentration in Lp. In summer, ewe lambs showed the typical daily preference pattern, selecting Lp in the morning to ensure a greater quality and showing no preference during the afternoon to fill the rumen with higher fibre content. In addition, greater sheath weight per tiller in Bv could make it less desirable, as the decrease in bite rate in the species was likely due to a higher shear strength and lower pasture sward mass per bite which increased foraging time. These results provided evidence on how Bv characteristics influence ewe lamb's preference; but more research is needed on how this will affect preference for Lp and Bv in a mixed pasture.

Proximal tibial osteophyte volumes are correlated spatially and with knee alignment: a quantitative analysis suggesting the influence of biochemical and mechanical factors in the development of osteophytes.

OBJECTIVE: To characterize the differences and correlations in osteophyte volumes between and within proximal tibial compartments, and to assess the correlations between osteophyte volumes and the femorotibial angle. DESIGN: CT scans of 73 knees with predominantly medial femorotibial osteoarthritis (21 K/L2, 28 K/L3, 24 K/L4) were retrospectively analyzed using a new, reproducible method measuring total and subregional osteophyte volumes in the medial and lateral compartments. Non-parametric statistics was used for comparison and correlation analyses. RESULTS: Total osteophyte volumes were larger in the medial than in the lateral compartment for all severity groups (p < 0.05). Additionally, statistically significant differences were observed among subregions of the lateral compartment in K/L3 and K/L4 knees. Statistically significant positive correlations were found between the medial and lateral total osteophyte volumes in K/L3 and K/L4 knees (ρ ≥ 0.44, p = 0.03), and among most subregional osteophyte volumes within each compartment in K/L3 knees. Markedly fewer statistically significant correlations were present in K/L2 and K/L4 knees. In K/L3 knees, the femorotibial angle was statistically significantly positively correlated with the total osteophyte volume in the medial compartment (ρ = 0.50, p = 0.01), with osteophyte volumes in most medial subregions, and with the osteophyte volume in the lateral posterior subregion (ρ = 0.40, p = 0.05). CONCLUSIONS: Quantitative assessment of osteophytes may bring insight on factors influencing their development. Positive correlations of osteophyte volumes found between and within compartments suggest the influence of biochemical mediators acting on the entire joint, while positive correlations between the femorotibial angle and osteophyte volumes suggest a role of mechanical factors. These hypotheses are to be further confirmed.

Configuration of daily grazing and searching of growing beef cattle in grassland: observational study.

Many of the studies in Campos grasslands focus on management aspects such as the control of herbage allowance, and application of nutrients and/or overseeding with legumes. However, there is little literature on how the Campos grassland resource is utilised, especially regarding the grazing pattern and the relationship between pasture quantity and quality on daily grazing activities. The study of the ingestive behaviour in species-rich and heterogeneous native grasslands during daylight hours, and understanding how animals prioritise quality or quantity of intake in relation to pasture attributes, are important to comprehend the ingestive-digestive processes modulating the energy intake of animals and to achieve a better grazing management. Therefore, the objective was to describe and quantify the daily grazing behaviour of growing cattle grazing native pasture with different structures as a result of different management practices, and study the relationship of pasture attributes and intake through multivariate analysis. The study was carried out at the Faculty of Agronomy, Paysandú, Uruguay. Treatments were native grassland, overseeding with Trifolium pratense and Lotus tenuis + phosphorus, and native pasture + nitrogen-phosphorus. Grazing activities were discriminated into grazing, searching (defined when animals take 1-2 bites in one feeding station and then change to another feeding station and so on), ruminating and idling. The probability of time allocated to each activity was continuously measured during daylight hours (0700-1930) and was related to pasture structure and forage quality using regression tree models, while the bite rate was determined every 2 h. The diurnal pattern of growing cattle showed grazing and searching sessions, followed by ruminating and idling sessions. The length of sessions (as the probability of time allocated to each activity) varied throughout the day. The grazing probability was greater during afternoon than morning and midday (0.74 vs 0.45 vs 0.46, respectively), and it was associated with higher bite rate (34.2 bites/min). Regression tree models showed different grazing, searching and ruminating strategies according to pasture attributes. During the morning, animals modified grazing, searching, ruminating and idling strategies according to bite rate, crude protein in diet and herbage allowance. At midday, they only adjusted ruminating and idling, while during afternoon sessions, grazing activities were modified by pasture quantity attributes such as herbage mass and herbage allowance. By controlling the herbage allowance, herbage mass and pasture height, animals prioritise quality in the morning and quantity in the afternoon, integrating and modifying the grazing-searching and ruminating-idling pattern.

Longitudinal changes in tibial and femoral cartilage thickness are associated with baseline ambulatory kinetics and cartilage oligomeric matrix protein (COMP) measures in an asymptomatic aging population.

OBJECTIVE: To address the need for early knee osteoarthritis (OA) markers by testing if longitudinal cartilage thickness changes are associated with specific biomechanical and biological measures acquired at a baseline test in asymptomatic aging subjects. DESIGN: Thirty-eight asymptomatic subjects over age 45 years were studied at baseline and at an average of 7-9 year follow-up. Gait mechanics and knee MRI were measured at baseline and MRI was obtained at follow-up to assess cartilage thickness changes. A subset of the subjects (n = 12) also had serum cartilage oligomeric matrix protein measured at baseline in response to a mechanical stimulus (30-min walk) (mCOMP). Baseline measures, including the knee extension (KEM), flexion (KFM), adduction (KAM) moments and mCOMP, were tested for associations with cartilage thickness changes in specific regions of the knee. RESULTS: Cartilage change in the full medial femoral condyle (p = 0.005) and external medial femoral region (p = 0.041) was negatively associated with larger early stance peak KEM. Similarly, cartilage change in the full medial femoral region (p = 0.009) and medial femoral external region (p = 0.043) was negatively associated with larger first peak KAM, while cartilage change in the anterior medial tibia was positively associated with larger first peak KAM (p = 0.003). Cartilage change in the anterior medial tibia was also significantly associated (p = 0.011) with mCOMP levels 5.5-h post-activity (percentage of pre-activity levels). CONCLUSIONS: Interactions found between gait, mechanically-stimulated serum biomarkers, and cartilage thickness in an at-risk aging asymptomatic population suggest the opportunity for early detection of OA with new approaches that bridge across disciplines and scales.

Reform of the 3rd cycle in surgery training.

The main objectives of the reform of the 3rd cycle of medical studies in France that was instituted in 2017 after eight years of preparation, are to train future specialists in a consistent and equitable fashion and to replace the previous time-based qualification by training based on the progressive acquisition of skills. This reform was an opportunity for the 13 different French surgical specialty Colleges involved to share reflections on what a surgeon actually was and to define training in surgical sub-specialties. The current reform is well adapted to these specifications and has fostered training models that are consistent with each other. This article discusses the historical construction of this reform, what will change in the training of future surgeons, as well as some points that warrant caution. The third cycle reform has also triggered a reform of the second cycle, which is expected to come into force for the 2020 academic year. Its objective will be to eliminate the guillotine effect created by the National Classifying Examinations and to allow students to better understand and test their desire and skills for a given specialty. It will be up to these same surgical Colleges to determine how to do this for the sub-specialties of the "surgery" discipline.

[Study of practices: What do general practitioners first propose when faced with asymptomatic lower extremity peripheral artery disease?] / Enquête de pratiques : que proposent en premier les médecins généralistes devant une artériopathie asymptomatique des membres inférieurs ?

INTRODUCTION: Peripheral artery disease of lower limbs (PAD) can be discovered at an asymptomatic stage by the realization of systolic pressure indices. The 2006 recommendations of the French National Authority for Health on AOMI encourage the systematic prescription of antiplatelet agents; the 2012 recommendations on the proper use of antiplatelet agents no longer encourage it in the case of asymptomatic PAD. These two recommendations still coexist. Our objective was to determine the management of an asymptomatic PAD by general practitioners. METHODS: Descriptive and analytical epidemiological study, with analysis of practices, prospectively addressed by postal questionnaire to a randomized sample of 220 GPs practicing in the European Metropolis of Lille between December 15, 2016 and February 15, 2017. The question was: "if an asymptomatic PAD is discovered in a 50-year-old patient who is otherwise in good general condition, what do you generally do?" RESULTS: Our sample was 92 general practitioners (42% participation). Of these, only 6 were practicing HPIs. Before an asymptomatic PAD, management included an opinion from an angiologist (84%) and/or a cardiologist (75%) before the drug was prescribed (antiplatelet agent for 57%, statin for 33% and ACE inhibitor for 14%). CONCLUSION: The extension assessment was carried out in more than 8 out of 10 cases. The use of antiplatelet antiaggregants was significant, which can be explained by the coexistence of divergent recommendations. The rapid clarification of recommendations is essential with the evolution of scientific data.

Changes in lower limb biomechanics when following floor-projected foot placement visual cues for gait rehabilitation.

BACKGROUND: Lately, the projection of foot placement visual cues onto the floor has been considered for use in gait rehabilitation. While promising, this approach needs further basic assessment to ensure proper uses. RESEARCH QUESTION: Does following floor-projected foot placement visual cues of one's natural walking pattern induce gait mechanics changes immediately or after a practice period? METHODS: Gait mechanics data from fifteen healthy individuals (7 female, 25.4 ±â€¯5.0 years, 21.5 ±â€¯1.68 kg/m2) was collected during normal walking without visual cues, and during two testing phases (immediate and after 45-60 min of practice) of walking with floor-projected visual cues depicting their normal spatial parameters. Magnitudes and variabilities of spatial gait parameters and sagittal plane lower limb kinematics and kinetics were compared between the three testing phases using repeated measures ANOVA and post-hoc paired t-tests. RESULTS: Compared to normal walking without foot placement visual cues, there was a statistically significant (p < 0.05) increase in stride length (maximum change of 0.01 ±â€¯0.01 m), stance phase knee flexion (2.0 ±â€¯2.5°), and swing phase hip flexion (1.2 ±â€¯1.3°) in both immediate and post-practice testing phases, along with an increase in terminal stance hip (0.28 ±â€¯0.38 %BW*Ht) and knee (0.25 ±â€¯0.25 %BW*Ht) flexion moments in the immediate testing phase. All of these changes between testing phases were smaller than their corresponding normal gait smallest real differences (SRD). With the addition of visual cues, variability was statistically significantly decreased in spatial parameters and increased in knee flexion angle at heel strike and knee flexion moment in terminal stance. SIGNIFICANCE: While biomechanical changes were observed, their magnitudes were small enough to suggest that floor-projected visual cues can be used in gait retraining without introducing unintended gait changes. Furthermore, the results suggested that lengthy practice periods are not necessary. The validity of these observations will, however, need to be confirmed in cases of severe impairments.

Relationships between cartilage thickness and subchondral bone mineral density in non-osteoarthritic and severely osteoarthritic knees: In vivo concomitant 3D analysis using CT arthrography.

OBJECTIVE: To test whether subchondral bone mineral density (sBMD) and cartilage thickness (CTh) of femoral condyles are correlated in knees without and with severe medial femorotibial osteoarthritis (OA), using a subregional analysis with computerized tomography (CT) arthrography. METHODS: CT arthrograms of 50 non-OA (18 males, 58.7 (interquartile range (IQR) = 6.6 years)) and 50 severe medial OA (24 males, 60.5 (IQR = 10.7) years) knees, were retrospectively analyzed. Bone and cartilage were segmented using custom-designed software, leading to 3D models on which each point of the subchondral surface is given a CTh and sBMD value. The average sBMD and CTh were then calculated for the entire weight-bearing regions as well as specific subregions of interest. Linear bivariate and multivariable analyses were performed to test for relationships between sBMD and CTh (regional and subregional measures, or medial-to-lateral ratios), with confounders of age, gender, femoral bone size and femorotibial angle. RESULTS: In non-OA knees, the sBMD and CTh medial-to-lateral ratios were positively correlated for the total region and the external and internal subregions (r ≥ 0.341, P ≤ 0.015). In OA knees, sBMD and CTh medial-to-lateral ratios were negatively correlated for the total region and the external and central subregions (r ≤ -0.538, P < 0.001). Additional positive/negative relationships in the non-OA/OA knees were observed between sBMD and CTh measures in the medial compartment. CONCLUSIONS: The positive correlation between sBMD and CTh in non-OA knees, and the negative one in OA knees, bring support to the theory of a subchondral bone/cartilage functional unit, which could help to better understand the pathophysiology of OA.

[Abortion in Hauts-de-France: When to expect the first appointment?] / Interruption volontaire de grossesse dans les Hauts-de-France : quel délai pour un premier rendez-vous ?

BACKGROUND: According to the French National Authority for Health ("Haute Autorité de santé"), the first appointment for an abortion should take place within five days of the request. Whether this deadline is met or not in the Hauts-de-France region is not known. AIM: The aim of this study was to measure the time needed to get a first appointment for an abortion in Hauts-de-France. METHOD: We conducted a telephone survey of health facilities, family planning and registered practitioners practicing abortions in the Hauts-de-France region, to determine the next appointment available for a woman requesting an abortion. The calls took place between April 10 and 14, 2017. The time needed to get a first appointment (means±standard deviations) was calculated for the region, the departments, the districts and the health facilities and practitioners. RESULTS: We contacted 93 health facilities and practitioners and 70 were included in the study. The time needed to get a first appointment for an abortion in Hauts-de-France was measured at 5.25±5.20 days: 6.32±4.72 days for health facilities, 3.84±5.11 days for gynecologists, 5.22±5.88 days for general practitioners and 0.67±0.58 days for private-practice midwives. Fifty-six percent of health facilities and practitioners gave the appointment within five days. Between the districts, the average time varied from 1 to 15.5 days. CONCLUSION: The average time needed to get a first appointment for an abortion in Hauts-de-France was near the 5-day deadline recommended by the French National Authority for Health. The training of private practice midwives and general practitioners may be the first step in shortening it in some districts where access to health care is limited.

Modeling knee osteoarthritis pathophysiology using an integrated joint system (IJS): a systematic review of relationships among cartilage thickness, gait mechanics, and subchondral bone mineral density.

OBJECTIVE: To introduce an integrated joint system (IJS) model of joint health and osteoarthritis (OA) pathophysiology through a systematic review of the cross-sectional relationships among three knee properties (cartilage thickness, gait mechanics, and subchondral bone mineral density). METHODS: Searches using keywords associated with the three knee properties of interest were performed in PubMed, Scopus, and Ovid databases. English-language articles reporting cross-sectional correlations between at least two knee properties in healthy or tibiofemoral OA human knees were included. A narrative synthesis of the data was conducted. RESULTS: Of the 5600 retrieved articles, 13 were included, eight of which reported relationships between cartilage thickness and gait mechanics. The 744 tested knees were separated into three categories based on knee health: 199 healthy, 340 at-risk/early OA, and 205 late OA knees. Correlations between knee adduction moment and medial-to-lateral cartilage thickness ratios were generally positive in healthy, inconclusive in at-risk/early OA, and negative in late OA knees. Knee adduction moment was positively correlated with medial-to-lateral tibial subchondral bone mineral density ratios in knees of all health categories. One study reported a positive correlation between lateral tibial subchondral bone mineral density and femoral cartilage thickness in at-risk/early OA knees. CONCLUSIONS: The correlations identified between knee properties in this review agreed with the proposed relationship-based IJS model of OA pathophysiology. Accordingly, the IJS model could provide insights into overcoming current barriers to developing disease-modifying treatments by considering multiple aspects of OA disease, aspects that could be assessed simultaneously at an in vivo system level.

Contribution of computational model for assessment of heart tissue local stress caused by suture in LVAD implantation.

STUDY: Implantation of a Left Ventricular Assist Device (LVAD) may produce both excessive local tissue stress and resulting strain-induced tissue rupture that are potential iatrogenic factors influencing the success of the surgical attachment of the LVAD into the myocardium. By using a computational simulation compared to mechanical tests, we sought to investigate the characteristics of stress-induced suture material on porcine myocardium. METHODS: Tensile strength experiments (n = 8) were performed on bulk left myocardium to establish a hyperelastic reduced polynomial constitutive law. Simultaneously, suture strength tests on left myocardium (n = 6) were performed with a standard tensile test setup. Experiments were made on bulk ventricular wall with a single U-suture (polypropylene 3-0) and a PTFE pledget. Then, a Finite Element simulation of a LVAD suture case was performed. Strength versus displacement behavior was compared between mechanical and numerical experiments. Local stress fields in the model were thus analyzed. RESULTS: A strong correlation between the experimental and the numerical responses was observed, validating the relevance of the numerical model. A secure damage limit of 100 kPa on heart tissue was defined from mechanical suture testing and used to describe numerical results. The impact of suture on heart tissue could be accurately determined through new parameters of numerical data (stress diffusion, triaxiality stress). Finally, an ideal spacing between sutures of 2 mm was proposed. CONCLUSION: Our computational model showed a reliable ability to provide and predict various local tissue stresses created by suture penetration into the myocardium. In addition, this model contributed to providing valuable information useful to design less traumatic sutures for LVAD implantation. Therefore, our computational model is a promising tool to predict and optimize LVAD myocardial suture.

Quantitative regional and sub-regional analysis of femoral and tibial subchondral bone mineral density (sBMD) using computed tomography (CT): comparison of non-osteoarthritic (OA) and severe OA knees.

OBJECTIVE: This study aimed to compare subchondral bone mineral density (sBMD) between non-radiographic osteoarthritic (OA) and medial femorotibial OA knees, using computed tomography (CT). DESIGN: CT exams from 16 non-radiographic OA (KL grade < 2) and 16 severe medial OA (KL grade ≥ 3) knees (average age of 61.7 ± 3 and 62.2 ± 5 years old respectively, 50% male in each group), were retrospectively analyzed. CT exams were segmented and 3D maps of sBMD based on the CT number in the most superficial 3 mm of femoral and tibial subchondral bone were computed. Average sBMD and medial-to-lateral sBMD ratios were calculated for total load-bearing regions and for sub-regions of interest in the femur and tibia. RESULTS: The analysis of total load-bearing regions did not reveal any significant difference between groups, except for the lateral tibia, where OA knees had lower sBMD. Sub-regional analysis unveiled differences with some sub-regions of the femur and tibia presenting significantly lower (in the lateral compartment) or higher (in the medial compartment) sBMD in OA knees compared to non-OA knees. The M/L sBMD ratios were significantly higher for OA knees compared to non-OA knees for all regions and sub-regions, except for the internal sub-regions. CONCLUSIONS: sBMD locally differs between non-OA and OA knees, in agreement with prior knowledge on biomechanics. CT proved to be a valuable tool for 3D analysis of femoral and tibial sBMD, which can be used in future studies to describe the chronology of sBMD alterations and improve our understanding of the role of subchondral bone in knee OA.

Speed, age, sex, and body mass index provide a rigorous basis for comparing the kinematic and kinetic profiles of the lower extremity during walking.

The increased use of gait analysis has raised the need for a better understanding of how walking speed and demographic variations influence asymptomatic gait. Previous analyses mainly reported relationships between subsets of gait features and demographic measures, rendering it difficult to assess whether gait features are affected by walking speed or other demographic measures. The purpose of this study was to conduct a comprehensive analysis of the kinematic and kinetic profiles during ambulation that tests for the effect of walking speed in parallel to the effects of age, sex, and body mass index. This was accomplished by recruiting a population of 121 asymptomatic subjects and analyzing characteristic 3-dimensional kinematic and kinetic features at the ankle, knee, hip, and pelvis during walking trials at slow, normal, and fast speeds. Mixed effects linear regression models were used to identify how each of 78 discrete gait features is affected by variations in walking speed, age, sex, and body mass index. As expected, nearly every feature was associated with variations in walking speed. Several features were also affected by variations in demographic measures, including age affecting sagittal-plane knee kinematics, body mass index affecting sagittal-plane pelvis and hip kinematics, body mass index affecting frontal-plane knee kinematics and kinetics, and sex affecting frontal-plane kinematics at the pelvis, hip, and knee. These results could aid in the design of future studies, as well as clarify how walking speed, age, sex, and body mass index may act as potential confounders in studies with small populations or in populations with insufficient demographic variations for thorough statistical analyses.

Altered gait mechanics and elevated serum pro-inflammatory cytokines in asymptomatic patients with MRI evidence of knee cartilage loss.

OBJECTIVE: To test if sagittal plane gait mechanics parameters and serum inflammation levels differ between healthy asymptomatic subjects and asymptomatic subjects with magnetic resonance imaging (MRI) evidence of cartilage loss. DESIGN: Gait mechanics and resting serum tumor necrosis factor-α (TNFα) concentrations were measured for two groups of asymptomatic subjects recruited for a previous study: Pre-Osteoarthritis (OA) subjects had MRI evidence of partial- or full-thickness knee cartilage loss in at least one compartment (n = 52 (30 female), 1.7 ± 0.1 m, 85.3 ± 18.9 kg, 44 ± 11 years); Control subjects had no MRI features of cartilage loss, osteophytes, bone marrow lesions, nor meniscal pathology in either knee (n = 26 (13 female), 1.7 ± 0.1 m, 74.6 ± 14.9 kg, 34 ± 10 years). Discrete measures of sagittal plane gait kinematics and kinetics were compared between subject groups and adjusted for age and body mass index (BMI) using analysis of covariance (ANCOVA). Serum TNFα concentrations were compared between groups using bootstrap t-test. RESULTS: The Pre-OA group had less extended knees (P = 0.021) and decreased maximum external knee extension moment (P = 0.0062) in terminal stance during gait, as well as increased resting serum TNFα concentration (P = 0.040) as compared to Control subjects. There were no group differences in heel strike flexion angle (P = 0.14), in maximum knee flexion moment (P = 0.91), nor in first peak knee adduction moment (KAM) (post-hoc analysis, P = 0.39). CONCLUSIONS: The finding that asymptomatic subjects with cartilage loss had gait and inflammatory characteristics similar to those previously reported in symptomatic OA patients supports the idea that there are specific mechanical and biological factors that precede the onset of knee pain in the pathogenesis of OA.

Assessment of endothelial damage and cardiac injury in a mouse model mimicking thrombotic thrombocytopenic purpura.

Essentials Endothelial injury is thought to be a key event in thrombotic thrombocytopenic purpura (TTP). Endothelial and cardiac damages were assessed in a model of TTP using ADAMTS-13 knockout mice. Damages of cardiac perfusion and function were associated with nitric oxide pathway alteration. Endothelial dysfunction constitutes a critical event in TTP development and cardiac injury. SUMMARY: Background Cardiac alterations represent a major cause of mortality in patients with thrombotic thrombocytopenic purpura (TTP). Endothelial injury remains poorly defined, but seems to be a key initiating event leading to the formation of platelet-rich thrombi in TTP patients. Objectives To assess the changes in endothelial function and the induced cardiac damage in a mouse model of TTP. Patients/methods We used an animal model in which TTP-like symptoms are triggered by injection of 2000 units kg-1 of recombinant von Willebrand factor in ADAMTS-13 knockout mice. Results These mice developed TTP-like symptoms, i.e. severe thrombocytopenia, schistocytosis, and anemia. On day 2, magnetic resonance imaging demonstrated a decrease in left ventricular perfusion associated with alteration of left ventricular ejection fraction, fractional shortening, and cardiac output, suggesting early systolic dysfunction. This was associated with decrease in endothelium-mediated relaxation responses to acetylcholine in mesenteric and coronary arteries, demonstrating severe early endothelial dysfunction. In parallel, we showed decreased cardiac expression of endothelial nitric oxide (NO) synthase and increased expression of antioxidant enzymes, suggesting alteration of the NO pathway. At this time, cardiac immunohistochemistry revealed an increase in the expression of VCAM-1 and E-selectin. Conclusion This study provides evidence that the heart is a sensitive target organ in TTP, and shows, for the first time, strong mesenteric and coronary endothelial dysfunction in an induced-TTP model. The mechanisms incriminated are the occurrence of a pro-oxidant state, and proadhesive and proinflammatory phenotypes. This previously largely unrecognized vascular dysfunction may represent an important contributor to the systemic organ failure occurring in TTP.

Editor's Choice - Ex vivo Renal Artery Repair with Kidney Autotransplantation for Renal Artery Branch Aneurysms: Long-term Results of Sixty-seven Procedures.

OBJECTIVE/BACKGROUND: To evaluate the long-term outcome of renal revascularization by ex vivo renal artery reconstruction and autotransplantation for renal artery branch aneurysms (RABAs). METHODS: Between 1991 and 2015, 67 ex vivo renal artery reconstructions with kidney autotransplantation were performed in 55 adults (mean age 47 years) and 10 children to repair 87 RABAs. The main underlying disease was fibromuscular dysplasia in 34 patients. Other etiologies were systemic congenital disease in eight patients, spontaneous dissecting aneurysms in five, iatrogenic aneurysms in three, atheromatous aneurysms in two and unknown etiology in 13. Median RABA diameter was 20.5 mm. Fifty-three patients (82%) were hypertensive, 60 had normal renal function and no patient was on hemodialysis. Seven patients (11%) were operated on after failure of an endovascular procedure. The mean number of renal artery branches repaired per patient was 3.5 and multiple aneurysms were treated in 14 patients (22%). The hypogastric artery was used in 41 patients, the saphenous vein in 18, the superficial femoral artery in five and a combination of different materials in three. RESULTS: No deaths occurred during the first 30 days. Primary patency at 30 days was 90.8% following to six early thromboses. Three patients (5%) were lost to follow up. No other thrombosis occurred. At 8 years, the primary and primary-assisted patency were 88% and 91%, respectively. Survival was 95% at 9 years. Among the 53 hypertensive patients, two were lost to follow up. At 9 years, 22 (43%) were cured and nine (18%) were improved with a significant reduction of antihypertensive medication (p < .05). The pre-operative modification of the diet in renal disease (MDRD) clearance was 93 ± 29 mL/minute, the immediate post-operative MDRD was 94 ± 33 mL/minute, and at the end of follow up it was 86 ± 26 mL/minute (p > .05). CONCLUSION: Ex vivo renal artery reconstruction for complex RABAs eliminates the risk of rupture, confers a benefit to hypertension, and preserves renal function with a satisfactory long-term patency.

Amplatzer Plug to Occlude the Internal Iliac Artery During Endovascular Aortic Aneurysm Repair: A Large Multicenter Study.

OBJECTIVE: During endovascular repair of abdominal aortic aneurysms (EVAR), in the absence of a distal iliac landing zone, the Amplatzer plug is increasingly being used to replace other internal iliac artery (IIA) embolization techniques. This study aimed at assessing the technical success, complication occurrence, and durability of the Amplatzer plug for IIA embolization. METHOD: From January 1, 2007 to December 31, 2013, all consecutive patients who underwent internal iliac embolization with an Amplatzer plug during EVAR were included in the study. There were 169 patients, (160 men, 9 women, mean 75 ± 9 years), treated by unilateral (158 cases, 93%) or bilateral (11 cases, 7%) embolization of the IIA, performed either separately prior to (65 cases, 38.5%) or during EVAR (104 cases, 61.5%). Follow up CT scan and/or US scan were performed 1 month after treatment and yearly thereafter. The inclusions were done retrospectively but the series was continuous and consecutive. Data were collected and analyzed using acquisition REDCap software. RESULTS: The technical success rate was 97.6%. Failures were device migration (n = 1), navigation failure (n = 2), and release outside the target zone (n = 1). On average, 1.43 plugs were required to achieve the embolization. The average amount of contrast agent for the embolization procedure was 111 ± 51 mL and the radiation dose was 127,777 ± 89,528 mGy/cm(2). The total fluoroscopy time was 854 ± 538 seconds. No re-canalization of the IIA trunk was observed during follow up. Complications were buttock claudication (n = 41, 24.3%), which resolved in 24 cases (58.5%, 24/41) at the first follow up, and intestinal ischemia requiring limited bowel resection in two cases. CONCLUSION: This multicenter study is the largest published to date. It demonstrates the efficacy and reliability of the Amplatzer plug to embolize the IIA during EVAR, with few side effects.

Estrogens are needed for the improvement in endothelium-mediated dilation induced by a chronic increase in blood flow in rat mesenteric arteries.

Resistance arteries play a key role in the control of local blood flow. They undergo outward remodeling in response to a chronic increase in blood flow as seen in collateral artery growth in ischemic disorders. We have previously shown that mesenteric artery outward remodeling depends on the endothelial estrogen receptor alpha. As outward arterial remodeling is associated with improved endothelium-dependent dilation, we hypothesized that estrogens might also play a role in flow-mediated improvement of endothelium-dependent dilation. Local increase in blood flow in first order mesenteric arteries was obtained after ligation of adjacent arteries in three-month old ovariectomized female rats treated with 17-beta-estradiol (OVX+E2) or vehicle (OVX). After 2 weeks, diameter was equivalent in high flow (HF) than in normal flow (NF) arteries with a greater wall to lumen ratio in HF vessels in OVX rats. Acetylcholine-mediated relaxation was lower in HF than in NF vessels. eNOS and caveolin-1 expression level was equivalent in HF and NF arteries. By contrast, arterial diameter was 30% greater in HF than in NF arteries and the wall to lumen ratio was not changed in OVX+E2 rats. Acetylcholine-mediated relaxation was higher in HF than in NF arteries. The expression level of eNOS was higher and that of caveolin-1 was lower in HF than in NF arteries. Acetylcholine (NO-dependent)-mediated relaxation was partly inhibited by the NO-synthesis blocker L-NAME in OVX rats whereas L-NAME blocked totally the relaxation in OVX+E2 rats. Endothelium-independent relaxation (sodium nitroprusside) was equivalent in OXV and OVX+E2 rats. Similarly, serotonin- and phenylephrine-mediated contractions were higher in HF than in NF arteries in both OVX and OVX+E2 rats in association with high ratio of phosphorylated ERK1/2 to ERK1/2. Thus, we demonstrated the essential role of endogenous E2 in flow-mediated improvement of endothelium (NO)-mediated dilatation in rat mesenteric arteries.