Ultrasound-determined diameter measurements are more accurate than axial computed tomography after endovascular aortic aneurysm repair

ObjectiveThis study evaluated the correlation of ultrasound (US)-derived aortic aneurysm diameter measurements with centerline, three-dimensional (3-D) reconstruction computed tomography (CT) measurements after endovascular aortic aneurysm repair (EVAR).MethodsConcurrent CT and US examinations from 82 patients undergoing post-EVAR surveillance were reviewed. The aortic aneurysm diameter was defined as the major axis on the centerline images of 3-D CT reconstruction. This was compared with US-derived minor and major axis measurements, as well as with the minor axis measurement on the conventional axial CT images. Correlation was evaluated with linear regression analyses. Agreement between different imaging modalities and measurements was assessed with Bland-Altman plots.ResultsThe correlation coefficients from linear regression analyses were 0.92 between CT centerline major and US minor measurements, 0.94 between CT centerline major and US major measurements, and 0.93 between CT minor and centerline major measurements. Bland-Altman plots showed a mean difference of 0.11 mm between US major and CT centerline measurements compared with 5.38 mm between US minor and CT centerline measurements, and 4.25 mm between axial CT minor and centerline measurements. This suggested that, compared with axial CT and US minor axis measurements, US major axis measurements were in better agreement with CT centerline measurements. Variability between major and minor US and CT centerline diameter measurements was high (standard deviation of difference, 4.27-4.84 mm). However, high variability was also observed between axial CT measurements and centerline CT measurements (standard deviation of difference, 4.36 mm).ConclusionsThe major axis aneurysm diameter measurement obtained by US imaging for surveillance after EVAR correlates well and is in better agreement with centerline 3-D CT reconstruction diameters than axial CT

Evolution of WIfI: Expansion of WIfI Notation After Intervention

Nearly a decade ago, the Society for Vascular Surgery (SVS)'s wound, ischemia, and foot Infection (WIfI) classification was first developed to help assess overall limb threat. However, managing conditions such as diabetic foot ulcer and chronic limb-threatening ischemia can be complex. For instance, certain investigative findings might initially be pending such as the level of ischemia or extent of infection before the final classification is established. In addition, wounds evolve rapidly, and the current classification does not allow for tracking their progression over time during treatment. Therefore, we propose a supplemental consistent notation for scoring WifI re-assessment during treatment of a threatened limb inspired by the cancer staging before and after neoadjuvant treatment classification system. Thus, we describe the re-scoring system and how to use it. Our suggestion supports a coherent method to longitudinally communicate characteristics of a threatened limb. This has potential to support high quality interdisciplinary, patient-centered care and enhance the use of this classification in research. Further work is required to validate this modification of a common language of risk

Vascular smooth muscle cell apoptosis in aneurysmal, occlusive, and normal human aortas

AbstractPurpose: Apoptosis is a physiologic mechanism of cell death that regulates mass and architecture in many tissues. Apoptosis has been described as a feature in human vascular atherosclerosis and large vessel structural integrity. We examined the extent of vascular smooth muscle cell (VSMC) apoptosis in aneurysmal, occlusive, and normal human aortic tissue. Methods: Tissue samples of aneurysmal, occlusive, and normal human infrarenal aorta were evaluated. DNA fragmentation detection methods, immunohistochemistry, and DNA electrophoresis determined VSMC density, VSMC apoptosis, and apoptosis markers. Apoptotic cells and VSMC nuclei were counted with the use of computer-generated image analysis. Aortic subtypes were compared statistically by analysis of variance. Results: Seventeen aneurysmal, ten occlusive, and five normal human aortas were evaluated. By α1-actin immunostaining, VSMC density was least in aneurysmal aortas (271.8 ± 13.5 cells/high-power field [HPF]) compared with occlusive aorta (278.2 ± 39.4 cells/HPF) and normal aortas (291.0 ± 25.4 cells/HPF; P = not significant). Presence of apoptotic VSMCs was demonstrated by terminal deoxynucleotidyl transferase fragment end labeling and propidium iodide nuclear staining. VSMC apoptosis was greatest within aneurysmal aortas with 11.7 ± 1.5 cells/HPF compared with occlusive aortas with 3.3 ± 0.8 cells/HPF (P <.05) and normal aortas with 3.75 ± 4.6 cells/HPF (P <.05). Significant differences in apoptosis markers, p53 or bcl-2, could not be demonstrated by immunohistochemistry or DNA electrophoresis in aortic subtypes. Conclusion: Apoptosis of VSMCs is increased and VSMC density is decreased within the medial layer of aneurysmal aortic tissue. Structural degeneration of aortic tissue at the cellular level contributes to aneurysmal formation. (J Vasc Surg 2000;31:567-576.

Exploring discordant low amyloid beta and high neocortical tau positron emission tomography cases

Introduction: Neocortical 3R4R (3-repeat/4-repeat) tau aggregates are rarely observed in the absence of amyloid beta (Aβ). 18F-MK6240 binds specifically to the 3R4R form of tau that is characteristic of Alzheimer\u27s disease (AD). We report four cases with negative Aβ, but positive tau positron emission tomography (PET) findings. Methods: All Australian Imaging, Biomarkers and Lifestyle study of aging (AIBL) study participants with Aβ (18F-NAV4694) and tau (18F-MK6240) PET scans were included. Centiloid \u3c 25 defined negative Aβ PET (Aβ–). The presence of neocortical tau was defined quantitatively and visually. Results: Aβ– PET was observed in 276 participants. Four of these participants (one cognitively unimpaired [CU], two mild cognitive impairment [MCI], one AD) had tau tracer retention in a pattern consistent with Braak tau stages V to VI. Fluid biomarkers supported a diagnosis of AD. In silico analysis of APP, PSEN1, PSEN2, and MAPT genes did not identify relevant functional mutations. Discussion: Discordant cases were infrequent (1.4% of all Aβ– participants). In these cases, the Aβ PET ligand may not be detecting the Aβ that is present

Renal revascularization in Takayasu arteritis–induced renal artery stenosis

AbstractPurposeThis study was undertaken to define the long-term effects of renal revascularization on blood pressure, and renal and cardiac function in patients with Takayasu arteritis–induced renal artery stenosis (TARAS).MethodsTwenty-seven patients (25 women; mean age, 27 years) with TARAS underwent intervention. Primary, primary assisted, and secondary patency rates were determined, and the late effects on blood pressure, renal and cardiac function, and survival were analyzed.ResultsAll patients had hypertension (mean blood pressure, 167/99 mm Hg; 2.5 antihypertensive medications per patient). Mean estimated glomerular filtration rate in patients not receiving hemodialysis was 76 mL/min, and in five patients serum creatinine concentration was greater than 1.5 mg/dL. Three patients were hemodialysis-dependent, and two had intractable congestive heart failure. Forty interventions were performed, including 32 aortorenal bypass procedures, two repeat implantations, four nephrectomies, and two transluminal angioplasty procedures. Postoperative morbidity was 19%. There were no deaths. During follow-up (mean, 68 months), three graft stenoses, all due to intimal hyperplasia, and three graft occlusions occurred. Two of three graft stenoses were successfully revised. At 1, 3, and 5 years of follow-up, primary patency was 87%, 79%, and 79%, respectively; primary assisted patency was 93%, 89%, 89%, respectively; and secondary patency was 93%, 89%, and 89%, respectively. Intervention resulted in a decrease in blood pressure to a mean of 132/79 mm Hg (P < .0001), and the need for antihypertensive medications was reduced to one per patient (P < .01). Mean glomerular filtration rate increased to 88 mL/min (P < .005), and two patients no longer required hemodialysis. Congestive heart failure resolved in both patients, and did not recur. There were three deaths during follow-up, with 5-year and 10-year actuarial survival of 96% and 80%, respectively.ConclusionsRenal revascularization to treat TARAS is durable, has a salutary effect on blood pressure, and enhances long-term renal and cardiac function. This response establishes renal revascularization as a successful and durable intervention for TARAS, and a benchmark to which other therapies should be compared

Cross-sectional and Longitudinal Analysis of the Relationship Between A beta Deposition, Cortical Thickness, and Memory in Cognitively Unimpaired Individuals and in Alzheimer Disease

IMPORTANCE beta-amyloid (A beta) deposition is one of the hallmarks of Alzheimer disease. A beta deposition accelerates gray matter atrophy at early stages of the disease even before objective cognitive impairment is manifested. Identification of at-risk individuals at the presymptomatic stage has become a major research interest because it will allow early therapeutic interventions before irreversible synaptic and neuronal loss occur. We aimed to further characterize the cross-sectional and longitudinal relationship between A beta deposition, gray matter atrophy, and cognitive impairment

Higher coffee consumption is associated with slower cognitive decline and less cerebral Aβ-amyloid accumulation over 126 months: Data from the Australian imaging, biomarkers, and lifestyle study

Background: Worldwide, coffee is one of the most popular beverages consumed. Several studies have suggested a protective role of coffee, including reduced risk of Alzheimer’s disease (AD). However, there is limited longitudinal data from cohorts of older adults reporting associations of coffee intake with cognitive decline, in distinct domains, and investigating the neuropathological mechanisms underpinning any such associations. Methods: The aim of the current study was to investigate the relationship between self-reported habitual coffee intake, and cognitive decline assessed using a comprehensive neuropsychological battery in 227 cognitively normal older adults from the Australian Imaging, Biomarkers, and Lifestyle (AIBL) study, over 126 months. In a subset of individuals, we also investigated the relationship between habitual coffee intake and cerebral Aβ-amyloid accumulation (n = 60) and brain volumes (n = 51) over 126 months. Results: Higher baseline coffee consumption was associated with slower cognitive decline in executive function, attention, and the AIBL Preclinical AD Cognitive Composite (PACC; shown reliably to measure the first signs of cognitive decline in at-risk cognitively normal populations), and lower likelihood of transitioning to mild cognitive impairment or AD status, over 126 months. Higher baseline coffee consumption was also associated with slower Aβ-amyloid accumulation over 126 months, and lower risk of progressing to “moderate,” “high,” or “very high” Aβ-amyloid burden status over the same time-period. There were no associations between coffee intake and atrophy in total gray matter, white matter, or hippocampal volume. Discussion: Our results further support the hypothesis that coffee intake may be a protective factor against AD, with increased coffee consumption potentially reducing cognitive decline by slowing cerebral Aβ-amyloid accumulation, and thus attenuating the associated neurotoxicity from Aβ-amyloid-mediated oxidative stress and inflammatory processes. Further investigation is required to evaluate whether coffee intake could be incorporated as a modifiable lifestyle factor aimed at delaying AD onset

Assessment of a polygenic hazard score for the onset of pre-clinical Alzheimer’s disease

Background: With a growing number of loci associated with late-onset (sporadic) Alzheimer’s disease (AD), the polygenic contribution to AD is now well established. The development of polygenic risk score approaches have shown promising results for identifying individuals at higher risk of developing AD, thereby facilitating the development of preventative and therapeutic strategies. A polygenic hazard score (PHS) has been proposed to quantify age-specific genetic risk for AD. In this study, we assessed the predictive power and transferability of this PHS in an independent cohort, to support its clinical utility. Results: Using genotype and imaging data from 780 individuals enrolled in the Australian Imaging, Biomarkers and Lifestyle (AIBL) study, we investigated associations between the PHS and several AD-related traits, including 1) cross-sectional Aβ-amyloid (Aβ) deposition, 2) longitudinal brain atrophy, 3) longitudinal cognitive decline, 4) age of onset. Except in the cognitive domain, we obtained results that were consistent with previously published findings. The PHS was associated with increased Aβ burden, faster regional brain atrophy and an earlier age of onset. Conclusion: Overall, the results support the predictive power of a PHS, however, with only marginal improvement compared to apolipoprotein E alone

Longitudinal trajectories of basal forebrain volume in normal aging and Alzheimer\u27s disease

Dysfunction of the cholinergic basal forebrain (BF) system and amyloid- (A ) deposition are early pathological features in Alzheimer\u27s disease (AD). However, their association in early AD is not well-established. This study investigated the nature and magnitude of volume loss in the BF, over an extended period, in 516 older adults who completed A -PET and serial magnetic resonance imaging scans. Individuals were grouped at baseline according to the presence of cognitive impairment (CU, CI) and A status (A −, A +). Longitudinal volumetric changes in the BF and hippocampus were assessed across groups. The results indicated that high A levels correlated with faster volume loss in the BF and hippocampus, and the effect of A varied within BF subregions. Compared to CU A + individuals, A -related loss among CI A + adults was much greater in the predominantly cholinergic subregion of Ch4p, whereas no difference was observed for the Ch1/Ch2 region. The findings support early and substantial vulnerability of the BF and further reveal distinctive degeneration of BF subregions during early AD. © 2023 The Author(s

Visually identified Tau 18F-MK6240 PET patterns in symptomatic Alzheimer\u27s disease

Background: In Alzheimer\u27s disease, heterogeneity has been observed in the postmortem distribution of tau neurofibrillary tangles. Visualizing the topography of tau in vivo may facilitate clinical trials and clinical practice. Objective: This study aimed to investigate whether tau distribution patterns that are limited to mesial temporal lobe (MTL)/limbic regions, and those that spare MTL regions, can be visually identified using 18F-MK6240, and whether these patterns are associated with different demographic and cognitive profiles. Methods : Tau 18F-MK6240 PET images of 151 amyloid-β positive participants with mild cognitive impairment (MCI) and dementia were visually rated as: tau negative, limbic predominant (LP), MTL-sparing, and Typical by two readers. Groups were evaluated for differences in age, APOE ɛ4 carriage, hippocampal volumes, and cognition (MMSE, composite memory and non-memory scores). Voxel-wise contrasts were also performed. Results: Visual rating resulted in 59.6 % classified as Typical, 17.9 % as MTL-sparing, 9.9 % LP, and 12.6% as tau negative. Intra-rater and inter-rater reliability was strong (Cohen\u27s kappa values of 0.89 and 0.86 respectively). Tracer retention in a hook -like distribution on sagittal sequences was observed in the LP and Typical groups. The visually classified MTL-sparing group had lower APOE ɛ4 carriage and relatively preserved hippocampal volumes. Higher MTL tau was associated with greater amnestic cognitive impairment. High crtical tau was associated with greater impairments on non-memory domains of cognition, and individuals with high cortical tau were more likely to have dementia than MCI. Conclusion: Tau distribution patterns can be visually identified using 18F-MK6240 PET and are associated with differences in APOE ɛ4 carriage, hippocampal volumes, and cognition