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Background and Aims Barrett's esophagus (BE) is accompanied by an increased risk of developing esophageal cancer. Accurate risk‐stratification is warranted to improve endoscopic surveillance. Most data available on risk factors is derived from tertiary care centers or from cohorts with limited surveillance time or surveillance quality. The aim of this study was to assess endoscopic and clinical risk factors for progression to high‐grade dysplasia (HGD) or esophageal adenocarcinoma (EAC) in a large prospective cohort of BE patients from community hospitals supported by an overarching infrastructure to ensure optimal surveillance quality. Methods A well‐defined prospective multicenter cohort study was initiated in six community hospitals in the Amsterdam region in 2003. BE patients were identified by PALGA search and included in a prospective surveillance program with a single endoscopist performing all endoscopies at each hospital. Planning and data collection was performed by experienced research nurses who attended all endoscopies. Endpoint was progression to HGD/EAC. Results Nine hundred eighty‐five patients were included for analysis. During median follow‐up of 7.9 years (IQR 4.1–12.5) 67 patients were diagnosed with HGD (n = 28) or EAC (n = 39), progression rate 0.78% per patient‐year. As a clinical risk factor age at time of endoscopy was associated with neoplastic progression (HR 1.05; 95% CI 1.03–1.08). Maximum Barrett length and low‐grade dysplasia (LGD) at baseline were endoscopic predictors of progression (HR 1.15; 95% CI 1.09–1.21 and HR 2.36; 95% CI 1.29–4.33). Conclusion Risk of progression to HGD/EAC in a large, prospective, community‐based Barrett's cohort was low. Barrett's length, LGD and age were important risk factors for progression. (www.trialregister.nl NTR1789)

Over the past decades, great strides have been made to professionalize and increase access to transgender medicine. As the (biomedical) evidence base grows and conceptualizations regarding gender dysphoria/gender incongruence evolve, so too do ideas regarding what constitutes good treatment and decision-making in transgender healthcare. Against this background, differing care models arose, including the ‘Standards of Care’ and the so-called ‘Informed Consent Model’. In these care models, ethical notions and principles such as ‘decision-making’ and ‘autonomy’ are often referred to, but left unsubstantiated. This not only transpires into the consultation room where stakeholders are confronted with many different ethical challenges in decision-making, but also hampers a more explicit discussion of what good decision-making in transgender medicine should be comprised of. The aim of this paper is to make explicit the conceptual and normative assumptions regarding decision-making and client autonomy underpinning the ‘Standards of Care’ and ‘Informed Consent Model’ currently used in transgender care. Furthermore, we illustrate how this elucidation aids in better understanding stakeholders’ ethical challenges related to decision-making. Our ethical analysis lays bare how distinct normative ambiguities in both care models influence decision-making in practice and how foregrounding one normative model for decision-making is no moral panacea. We suggest that the first steps towards good decision-making in gender-affirming medical care are the acknowledgement of its inherent normative and moral dimensions and a shared, dialogical approach towards the decision-making process.

Background The majority of hepatitis C virus (HCV) infections are found in low- and middle-income countries, which harbor many region-specific HCV subtypes. Nevertheless, direct-acting antiviral (DAA) trials have almost exclusively been conducted in high-income countries, where mainly epidemically spread HCV subtypes are present. Recently, several studies have demonstrated suboptimal DAA efficacy for certain nonepidemic subtypes, which could hamper global HCV elimination. Therefore, we aimed to evaluate DAA efficacy in patients treated for a nonepidemic HCV genotype infection in the Netherlands. Methods We performed a nationwide retrospective study including patients treated with interferon-free DAAs for an HCV genotype other than 1a/1b/2a/2b/3a/4a/4d. The genotype was determined by NS5B region phylogenetic analysis. The primary end point was SVR-12. If stored samples were available, NS5A and NS5B sequences were obtained for resistance-associated substitutions (RAS) evaluation. Results We included 160 patients, mainly infected with nonepidemic genotype 2 (41%) and 4 (31%) subtypes. Most patients were from Africa (45%) or South America (24%); 51 (32%) were cirrhotic. SVR-12 was achieved in 92% (140/152) of patients with available SVR-12 data. Only 73% (8/11) genotype 3–infected patients achieved SVR-12, the majority being genotype 3b patients with 63% (5/8) SVR. Regardless of SVR, all genotype 3b patients had 30K and 31M RAS. Conclusions The DAA efficacy we observed in most nonepidemic genotypes in the Netherlands seems reassuring. However, the low SVR-12 rate in subtype 3b infections is alarming, especially as it is common in several HCV-endemic countries. Alongside earlier results, our results indicate that a remaining challenge for global HCV elimination is confirming and monitoring DAA efficacy in nonepidemic genotypes.

In this paper, for the first time we develop and benchmark the performance of three down-converting Field Effect Transistor (FE T) resistive mixers at millimeter wave (mm W) frequencies employing $\pmb{0.15-\mu \mathrm{m}}$ enhancement (E)-mode Gallium Arsenide (GaAs) pseudomorphic high electron mobility transistors (pHEMTs), depletion (D)-mode GaAs pHEMTs, and D-mode Gallium Nitride (GaN) pHEMTs. Our experimental results at 27 GHz demonstrate that the E-mode mixer achieves the highest reported input 3rd order intercept point (IIP3) of 37.5dBm at mm W frequencies to the best of our knowledge. Also, operating at the same LO drive up to 20 dBm, the E-mode GaAs mixer impressively out performs both the D-mode GaAs and GaN mixers.

Under the umbrella of the European Network for Light Ion Therapy (ENLIGHT), the project on Union of Light Ion Centers in Europe (ULICE), which was funded by the European Commission (EC/FP7), was carried out from 2009 to 2014. Besides the two pillars on Transnational Access (TNA) and Networking Activities (NA), six work packages formed the pillar on Joint Research Activities (JRA). The current manuscript focuses on the objectives and results achieved within these research work packages: “Clinical Research Infrastructure”, “Biologically Based Expert System for Individualized Patient Allocation”, “Ion Therapy for Intra-Fractional Moving Targets”, “Adaptive Treatment Planning for Ion Radiotherapy”, “Carbon Ion Gantry”, “Common Database and Grid Infrastructures for Improving Access to Research Infrastructures”. The objectives and main achievements are summarized. References to either publications or open access deliverables from the five year project work are given. Overall, carbon ion radiotherapy is still not as mature as photon or proton radiotherapy. Achieved results and open questions are reflected and discussed in the context of the current status of carbon ion therapy and particle and photon beam therapy. Most research topics covered in the ULICE JRA pillar are topical. Future research activities can build upon these ULICE results. Together with the continuous increase in the number of particle therapy centers in the last years ULICE results and proposals may contribute to the further growth of the overall particle therapy field as foreseen with ENLIGHT and new joint initiatives such as the European Particle Therapy Network (EPTN) within the overall radiotherapy community.

We present the case of a 56-year-old woman with moderate myopia and bilateral cataract who had cataract extraction and intraocular lens (IOL) implantation. Due to the patient's desire for spectacle independence, a trifocal IOL with toric correction for astigmatism was implanted. During the follow-up, it became obvious that the implanted IOL had rotated and tilted due to insufficient fixation in the large capsular bag of the myopic eye. An IOL explantation was therefore performed, and the original IOL was exchanged for a bifocal toric IOL with a larger overall diameter. Stable fixation of the IOL in the capsular bag was achieved, and after surgery in the second eye, the patient recovered good bilateral vision. This case illustrates the need for careful selection of IOL diameter and sizing even in patients with moderate myopia due to the potentially larger ocular dimensions in these patients.

BACKGROUND Although elevated serum levels of visinin-like protein 1 (VILIP-1), a neuron-specific calcium sensor protein, are associated with ischaemic stroke, only a single study has evaluated VILIP-1 as a biomarker of traumatic brain injury (TBI). The current proof-of-concept study was designed to determine whether serum VILIP-1 levels increase post-injury in a well-characterized rat unilateral cortical contusion model. METHODS Lateral flow devices (LFDs) rapidly (

Purpose To prospectively compare the diagnostic accuracy of controlled attenuation parameter (CAP) obtained with transient elastography and proton density fat fraction (PDFF) obtained with proton magnetic resonance (MR) spectroscopy with results of liver biopsy in a cohort of adult patients suspected of having nonalcoholic fatty liver disease (NAFLD). Materials and Methods The institutional review board approved this study. Informed consent was obtained from all patients. The authors evaluated 55 patients suspected of having NAFLD (40 men, 15 women). Patients had a median age of 52.3 years (interquartile range [IQR], 43.7-57.6 years) and a median body mass index of 27.8 kg/m2 (IQR, 26.0-33.1 kg/m2). CAP and PDFF measurements were obtained on the same day, within 27 days of biopsy (IQR, 7-44 days). CAP and PDFF were compared between steatosis grades by using the Jonckheere-Terpstra test. Diagnostic accuracies of CAP and PDFF for grading steatosis were assessed with receiver operating characteristic (ROC) analysis. Within-weeks reproducibility (CAP and PDFF) and within-session repeatability were assessed with linear regression analyses, intraclass correlation coefficients, and coefficients of variation. Results Steatosis grades at liver biopsy were distributed as follows: S0, five patients; S1, 24 patients; S2, 17 patients; and S3, nine patients. Both PDFF and CAP helped detect histologically proven steatosis (≥S1), but PDFF showed better diagnostic accuracy than CAP in terms of the area under the ROC curve (0.99 vs 0.77, respectively; P = .0334). PDFF, but not CAP, enabled the grading of steatosis (P < .0001). For within-weeks reproducibility, the intraclass correlation coefficient with PDFF was higher than that with CAP (0.95 vs 0.65, respectively; P = .0015); coefficients of variation were similar (19% vs 11%, P = .55). Within-session repeatability of CAP was good, with a coefficient of variation of 4.5%. Conclusion MR spectroscopy-derived PDFF is superior to CAP in detecting and grading liver steatosis in human NAFLD. © RSNA, 2017 Online supplemental material is available for this article.

A very wideband GaAs MMIC Schottky diode frequency doubler has been designed and tested; it has at least a 10–75 GHz output frequency range with indications it works to 90 GHz. Measured in a test fixture with 1.85 mm connectors over an output frequency of 10–67 GHz, it has 9 to 15 dB conversion loss, −15 to −25 dBc fundamental suppression, −22 to −35 dBc third harmonic suppression, and 15 to 20 dB input return loss, all including interconnect and connector losses. Additionally, calibrated wafer probe tests show it has under 16 dB conversion loss up to 75 GHz, and qualitative wafer probe tests indicates it works up to 90 GHz, in good agreement with simulated results. It is singly balanced with a broadside coupled 4:1 transmission line transformer that provides wideband impedance match and input ground return. This appears to be the widest operating bandwidth reported for a GaAs MMIC diode frequency doubler. A family of frequency doublers and mixers has been designed and built that use this new circuit topology.

A dynamic phantom has been developed to allow for measurement of 3D cell survival distributions and the corresponding distributions of the RBE-weighted dose (RBED) in the presence of motion. The phantom consists of two 96-microwell plates holding Chinese hamster ovary cells inside a container filled with culture medium and is placed on a movable stage. Basic biological properties of the phantom were investigated without irradiation and after irradiation with a carbon ion beam, using both a stationary (reference) exposure and exposure during motion of the phantom perpendicular to the beam with beam tracking. There was no statistically significant difference between plating efficiency measured in the microwells with and without motion (0.75) and values reported in the literature. Mean differences between measured and calculated cell survival for these two irradiation modes were within +/-5% of the target dose of 6 Gy (RBE).

Objective: To determine if an aberrant protein complex consisting of prostaglandin-d-synthase (PDS) and transthyretin (TTR) in CSF differentiates between subjects with Alzheimer disease (AD) and normal control (NC) subjects. Methods: Western blot analysis and a unique sandwich ELISA were used to quantify levels of complexed PDS/TTR in ventricular CSF of subjects with autopsy-verified diagnoses and in lumbar CSF of living subjects with mild to moderate probable AD and age-matched NC subjects. Ventricular CSF was obtained from short postmortem interval autopsies of 7 NC subjects (4 men/3 women), 12 diseased control (DC) subjects (7 men/5 women), 4 subjects with mild cognitive impairment (MCI) (2 men/2 women), and 8 subjects with late-stage AD (LAD) (4 men/4 women). Lumbar CSF was obtained from 15 subjects with probable AD (5 men/10 women) and 14 age-matched NC subjects (10 men/4 women) and was analyzed in a double-blind fashion. Results: A significant increase in complexed PDS/TTR in ventricular CSF was found in MCI and LAD subjects but not DC subjects compared with NC subjects. Double-blind analysis of complexed PDS/TTR in lumbar CSF showed a significant sixfold increase in levels of the PDS/TTR complex in living probable AD subjects compared with age-matched NC subjects and a 100% sensitivity and 93% specificity in the identification of subjects with AD. Conclusion: After further study of larger numbers of patients, quantifying prostaglandin-d-synthase/transthyretin complex in CSF may be useful in the diagnosis of Alzheimer disease, possibly in the early stages of the disease.

OBJECTIVE. The aim of this study was to test the hypothesis that screening for scoliosis is effective in reducing the need for surgical treatment. METHODS. The study was a case-control study. A total of 125 consecutive patients who were treated surgically for idiopathic scoliosis between January 2001 and October 2004 and who were born on or after January 1, 1984, were invited; 108 agreed to participate. A total of 216 control subjects were selected randomly and anonymously, matched with respect to age and gender. For 279 adolescents, exact screening exposure and outcomes could be analyzed. Case subjects were recruited from 4 university and 6 nonuniversity Dutch hospitals; control subjects were recruited from all 37 municipal health services in the Netherlands. RESULTS. Screen-detected patients received diagnoses at a significantly younger age than did otherwise-detected patients (10.8 ± 2.6 vs 13.4 ± 1.7 years). In total, 32.8% of the surgically treated patients had been screened between 11 and 14 years of age, compared with 43.4% of the control subjects. The odds ratio for being exposed to screening was 0.64. In total, 28% of the patients were diagnosed as having scoliosis before 11 years of age. CONCLUSIONS. Our results showed no evidence that screening for scoliosis reduced the need for surgery. Abolishing screening seems justified, especially because the effectiveness of early treatment with bracing is still strongly debated. A randomized, controlled trial on the effectiveness of treating patients with idiopathic scoliosis with bracing is urgently needed.

Calpains are calcium- and thiol-dependent proteases whose overactivation and degradation of various substrates have been implicated in a number of diseases and conditions such as cardiovascular dysfunction and ischemic stroke. With increasing evidence for calpain's role in cellular damage, the development of calpain inhibitors continues to be an important objective. Previously, we identified a highly specific calcium-dependent, calpain interacting peptide L-S-E-A-L, that showed homology to domains A and C of the only known endogenous inhibitor of calpains, calpastatin. This suggested that LSEAL had a calpain inhibitory function and synthetic LSEAL inhibited calpain I and II proteolysis of two calpain substrates, tau and alpha-synuclein. In the present study, we demonstrate that synthetic LSEAL is membrane permeable and is a potent inhibitor in two established models of calpain-mediated cell death using primary rat cortical neurons and SH-SY5Y neuroblastoma cells. In addition, we show that LSEAL inhibits calpain activity towards protein substrates as detected by an antibody to a calpain-specific breakdown product of spectrin. Taken together, these results suggest that LSEAL may represent a novel calpastatin mimetic with the potential for benefit in conditions of increased calpain activity such as stroke, traumatic brain injury or heart attack.

Continuous fetal heart rate (FHR) monitoring using transabdominal Doppler ultrasonography can be assumed to provide information about the viability of the bovine fetus during late gestation, as has been found in humans. To be able to recognize unfavourable fetal conditions, first the normal ranges of FHR parameters in cattle should be established. Therefore, in this study we aimed to determine the normal ranges of computerized FHR parameters, like basal fetal heart rate (BHR), number of accelerations and decelerations per hour and short and long term variation (STV and LTV) during the last 3 weeks before calving (n = 21 cows). Each cow had one recording in each of three episodes of 7 days before parturition. As recording time in the cow is limited, we also studied whether these FHR parameters differ between recordings of 30 and 60 min duration (n = 31 pairs of recordings). The outcomes of FHR recordings with a duration of 30 or 60 min did not differ significantly, except for a higher percentage of signal loss in the 60 min recordings. Therefore, determination of normal ranges was performed in 30 min recordings. BHR decreased from 3 to 2 weeks (114 to 109 bpm; P0.0001) before parturition and then remained constant until 2 days before calving. The mean number of accelerations per hour ranged between 4.4 and 5.0 h(-1) and did not change significantly with time. Compared to 3 weeks before parturition, STV was significantly higher at 2 weeks (P0.05), but not at 1 week before parturition (8.1, 10.0, and 9.2 ms, respectively). Changes in LTV showed a time course comparable to that of STV, but significance was not reached (51.4, 58.6, and 58.4 ms for respectively 3, 2 and 1 weeks before parturition). No decelerations were found during the period understudy. In conclusion, this study has provided normal ranges of bovine computerized FHR parameters during the last 3 weeks of gestation, allowing a comparison with data from cows with compromised gestations in future.

Purpose: This study investigated whether recommendations given to the treating vascular specialist and the GP by a multidisciplinary team of vascular specialists concerning the medical treatment of risk factors, based on international guidelines, led to an increased medication use in a high-risk population. Methods: Data were obtained from 618 patients enrolled in the SMART study, an ongoing single-center prospective cohort study of patients referred to the University Medical Center Utrecht for atherosclerotic vascular diseases. All patients underwent a vascular screening and their physicians received recommendations concerning the medical treatment of newly detected or not yet sufficiently treated vascular risk factors. After a median follow-up of 29 months, questionnaires about medication use were sent to 618 patients; 534 (86%) questionnaires were returned. Actual use of medication was compared with medical treatment recommendation given at baseline. Results: The proportion of patients on antihypertensive medication with hypertension (≥140/90 mmHg) and not diagnosed with coronary heart disease increased from 56% to 68% (95% confidence interval (95% CI) 2 – 23). The frequency of lipid-lowering medication use increased substantially from 47% to 69% (95% CI 17 - 28). The frequency of glucose-lowering medication use increased slightly from 11% to 14% (95% CI ‒ 1 – 7). The use of folic acid increased from 2% to 14% (95% CI 9 – 15) in patients with hyperhomocysteinaemia. Conclusions: Medical treatment recommendations, formulated by a multidisciplinary team, led to a significant increase in medication use. The increase is marginal compared with trends in medication use without this intervention in usual care.

Objectives. The beneficial effect of oral anticoagulants after infrainguinal venous bypass surgery is compromised by bleeding complications. We developed a model to identify patients, treated with anticoagulation, at risk of major haemorrhage and estimated whether this complication could have been prevented if patients had received aspirin. Design. Randomised clinical trial. Methods. Data of patients who participated in the Dutch Bypass Oral Anticoagulation or Aspirin Study were reanalysed using Cox regression. After infrainguinal bypass surgery these patients were randomised to oral anticoagulants (nZ1326) or aspirin (nZ1324). Results. Predictors of major haemorrhage for patients on oral anticoagulants were increased systolic blood pressure (R140 mmHg, hazard ratio [HR] 1.62), age R75 years (HR 2.77) and diabetes mellitus (HR 1.60). If the 345 patients in the highest risk quartile had received aspirin, major haemorrhages would have been reduced from 46 to 22, with no major changes in ischemic events and graft occlusions. In the subgroup with venous bypasses major haemorrhages would have been reduced from 27 to 13, at the cost of seven more ischemic events (mostly fatal) and 17 more graft occlusions. Conclusions. Treating patients at highest risk of major haemorrhage with aspirin instead of oral anticoagulants would have resulted in a reduction of non-fatal haemorrhages, but for venous bypasses this reduction was outweighed by an increase in ischemic events and graft occlusions. We still recommend treatment with oral anticoagulants after peripheral venous bypass surgery.

BACKGROUND: The aim of this study was to prospectively evaluate endoscopic resection (ER) combined with photodynamic therapy (PDT) for the treatment of selected patients with early neoplasia in Barrett's esophagus. METHODS: Patients with Barrett's esophagus and neoplastic lesions

Background and Purpose— In patients with severe obstruction of the internal carotid artery (ICA), it is recognized that the preoperative failure to visualize collaterals of the circle of Willis increases the risk of hemispheric ischemia before, during, and after carotid endarterectomy (CEA). The purpose of the present study was to assess the effect of CEA on the anatomy and function of the circle of Willis. Methods— Time-of-flight and phase-contrast MR angiography were used to study changes in vessel diameter and collateral flow of the circle of Willis in 48 patients with 70% to 99% ICA stenosis before and after CEA. Results— In patients with unilateral ICA stenosis, all preoperative vessel diameters on both sides of the circle of Willis were larger than in control subjects. All demonstrated a significant diameter decrease to reach normal values after CEA. Furthermore, preoperative collateral flow patterns normalized after CEA ( P =0.03). In patients with stenosis and contralateral ICA occlusion, CEA resulted in a significant increase in the prevalence of collateral flow via the anterior communicating artery (33% to 83%, P P Conclusions— CEA reduces the caliber of compensatory collateral channels to normal levels by MR angiography measurements in the presence of severe unilateral stenosis; when the opposite side is occluded and the stenosis is removed ipsilaterally, a greater amount of compensatory collateral circulation can be measured on both the occluded side and the fully opened side.

Purpose: To assess the value of MR angiography (MRA) with automatic table movement in a consecutive series of patients with peripheral arterial disease. Methods: Seventy-two patients underwent both conventional angiography (CA) and MRA for peripheral arterial occlusive disease. Both techniques were scored in a masked way. Consensus scoring for CA was compared with MRA scoring per observer. If there was a discrepancy in scoring of a segment on MRA and CA, the images were reviewed and a consensus arrived at. Results: Observer A found 7.4% and observer B found 6.5% of the segments could not be analyzed on MRA. Observer A scored 11.4% dissimilar on MRA and CA, observer B 15.2%. In the aortoiliac arteries, this was mainly caused by stents and overestimation of stenoses; in the crural arteries it resulted from underestimation of the stenoses on MRA. Overall sensitivity and specificity for the aortoiliac, femoropopliteal and crural vessels were respectively 90% and 91%, 90% and 96%, 59% and 96% for observer A, and 85% and 91%, 84% and 89%, 68% and 85% for observer B. Conclusion: Although MRA of the lower extremities is a promising technique, improvements still need to be made. In particular, MRA below the knee is suboptimal for clinical use.

Previous epidemiologic studies suggest that antihypertensive drugs may be protective against cognitive decline. To determine if subjects enrolled in the University of Kentucky longitudinal aging study who used antihypertensive drugs showed diminished progression to dementia, we used a 3-parameter logistic regression model to compare the rate of progression to dementia for subjects who used any of the five common categories of antihypertensive drugs to those with similar demographic characteristics but who did not use antihypertensives. Regression modeling showed that subjects who used calcium channel blockers (CCBs) but not the other classes of antihypertensives showed a significant decrease in the rate of progression to dementia. Significantly, use of CCBs ameliorated the negative effects of the presence of APOE-4 alleles on cognitive decline. To determine if CCBs could minimize amyloid beta peptide (Aβ1–42) production, H4 neuroglioma cultures transfected to overexpress APP were treated with various CCBs and Aβ1–42levels and levels of proteins involved in Aβproduction were quantified. Results show that treatment with nifedipine led to a significant decrease in levels of Aβ1–42, with no significant decrease in cell viability. Collectively, these data suggest that use of CCBs significantly diminishes the rate of progression to dementia and may minimize formation of Aβ1–42.

Background: During clinical evaluation of young women with peripheral arterial occlusive disease, we were surprised by the high prevalence of pregnancy loss in women with segmental stenosis confined to the aortoiliac segment. We wondered if increased occurrence of miscarriage is the result of high expression of vascular and obstetrical risk factors in these patients, or if it is related to localization of disease. In a case-control study designed to investigate risk factors for peripheral arterial occlusive disease in young women, we assessed the risk of miscarriage in these patients according to level of obstruction. Methods: A total of 202 female patients, aged 18–49 years and 466 healthy control women from a population based case-control study, donated venous blood samples and filled out a structured questionnaire concerning classical cardiovascular risk factors and obstetrical history. In all patients, diagnosis of peripheral arterial occlusive disease was confirmed by intra-arterial angiography. Patients were classified into two groups: those with and those without stenosis of the aortoiliac segment (aortoiliac disease). Results: In 77 of the 202 patients (38%) with peripheral arterial occlusive disease, the obstruction was confined to the aortoiliac segment. The occurrence of miscarriage was high (42%) in young women with aortoiliac disease. Compared to healthy controls, the risk of miscarriage increased 3-fold (OR 3.1; 95% CI 1.8–5.6) in these patients. Adjustment for obstetrical and vascular risk factors did not affect the risk estimate. Conclusion: This is the first study that identifies aortoiliac disease as a risk factor for pregnancy loss in young women. The risk of miscarriage is increased 3-fold in women with aortoiliac disease. The presence of vascular and obstetrical risk factors did not affect the strength of the association. Pregnancy loss could be the first sign of insufficient aortic circulation in these patients.

Introduction: fat derived microvascular endothelial cells (MVEC) seeded on prosthetic vascular grafts, improve patency in animals. Results in humans were disappointing, due to thrombogenicity and progressive intimal hyperplasia. Also in animals intimal hyperplasia was found. We postulate that contaminating cells present in the transplant are involved in the intimal hyperplasia. We developed a method to further purify human MVEC from 40–90%. Here we tested the effects of enrichment upon thrombogenicity and seeding-related intimal hyperplasia. Methods: liposuction fat was enzymatically digested and centrifuged. To enrich MVEC, contaminating macrophages and fibroblasts were removed with dynabeads coated with macrophage- and fibroblast-specific antibodies. Thrombogenicity was assessed by measuring tissue factor and thrombomodulin activity, presence of endothelial nitric oxide synthase and via perfusion of the cells with whole blood. To investigate seeding-related intimal hyperplasia, PTFE grafts were seeded with the cells and cultured for 3 weeks. Results: tissue factor activity of purified cells was reduced compared to nonpurified cells. Purified cells showed thrombomodulin activity and eNOS expression. Fragment 1+2 and Fibrinopeptide A generation after perfusion of purified cells were significantly lower than after perfusion of nonpurified cells, and only nonpurified cells were covered with platelets and fibrin. Prostheses seeded with nonpurified cells showed an EC monolayer above a multilayer of myofibroblasts, prostheses seeded with purified cells only showed a single EC monolayer. Mixing experiments with human umbilical cord EC (HUVEC) and fibroblasts showed that when more than 25% HUVEC were present a confluent EC layer was formed. When the amount of fibroblasts was 25% or less, no development of a subendothelial multilayer of myofibroblasts was found within 3 weeks. Conclusion: reduction of non-endothelial cell contamination of microvascular endothelial cell seeded grafts decreases thrombogenicity and might prevent seeding-related intimal hyperplasia.

Objective: Several studies have reported an association between abdominal aortic dilatation and peripheral arterial occlusive disease. Narrowing of aortic diameter, also called abdominal aortic hypoplasia, and peripheral arterial occlusive disease have received insufficient attention. Precise estimates of the relationship between aortic hypoplasia and peripheral arterial occlusive disease are lacking. In this study, we assessed the relationship between abdominal aortic diameter and peripheral arterial occlusive disease. Methods: In this cross-sectional study, we analyzed 1572 patients 18 to 79 years of age, newly referred to the vascular center of our hospital with clinically manifest atherosclerotic arterial disease or for treatment of cardiovascular risk factors. Diameter measurements were used to subdivide patients according to tertiles of abdominal aortic diameter. Peripheral arterial occlusive disease was assessed by adjusted Rose questionnaire, ankle-brachial pressure index, and the presence of gangrene or leg ulcers. Results: Compared with patients with normal aortic diameter, peripheral arterial occlusive disease was twice as prevalent in patients at both ends of the aortic diameter spectrum. When the lowest tertile was compared with the middle tertile in male patients, the adjusted odds ratio was 1.7 (95% CI, 1.0-3.1). When the highest tertile was compared with the middle tertile, the adjusted odds ratio was 2.1 (95% CI, 1.2-3.4). Similar results were found in female patients. The adjusted odds ratio of lowest versus middle tertile was 2.4 (95% CI, 1.1-5.0) and 1.8 (95% CI, 0.8-4.0) when the highest tertile was compared with the middle tertile. Conclusion: The risk of peripheral arterial occlusive disease was increased in the lower and upper distribution of aortic diameter. Apparently, both patients with an aortic diameter too large and patients with an aortic diameter too small are prone to peripheral arterial occlusive disease. This is the first large study that shows that small aortic diameter is associated with peripheral arterial occlusive disease. (J Vasc Surg 2001;34:1085-9.)

Purpose: Several antithrombotic therapies are available for the treatment of patients with peripheral vascular diseases. It is unknown how quality of life and costs of treatment are influenced by different therapies. This study assessed the cost-effectiveness of oral anticoagulants versus aspirin in patients after infrainguinal bypass grafting surgery. Methods: Clinical outcome events and event-free survival were collected from 2650 patients in 77 centers who participated in the Dutch Bypass Oral anticoagulants or Aspirin trial. Approximately half the patients had critical ischemia; 60% received vein grafts, and 20% had femorocrural bypass grafts. A model that was primarily driven by clinical outcome events was used as a means of determining quality of life (EuroQol EQ-5D) and costs for each patient. The main outcome measure was the incremental health care costs in relation to the additional number of quality-adjusted life years and the additional number of event-free years. Results: The mean costs during the 21 months of follow-up were ϵ 6875 per patient in the oral anticoagulants group versus ϵ 7072 in the aspirin group (difference, 197; 95% CI, –746 to 343). The event-free survival was 1.10 years in the group treated with oral anticoagulants versus 1.09 years in the group treated with aspirin (difference, 0.01; 95% CI, –0.07 to 0.08), whereas the corresponding quality-adjusted life years were 1.06 and 1.05, respectively (difference, 0.01; 95% CI, –0.03 to 0.06). Conclusion: Health care costs, event-free survival, and quality-adjusted life years in patients after infrainguinal bypass surgery were not different in patients treated with aspirin and patients treated with oral anticoagulants. The extra costs of monitoring patients treated with oral anticoagulants were limited and play no role in the decision for treatment. (J Vasc Surg 2001;34:254-62.)

Objective: to describe redistribution of cerebral blood flow in patients with severe internal carotid artery (ICA) stenoses in relation to contralateral ICA disease. Methods: sixty-six patients scheduled for carotid endarterectomy (CEA) were grouped according to severity of contralateral stenosis (

Objective: To provide a long-term perspective on the durability of the proximal abdominal aortic aneurysm endograft fixation from a single device series with perpendicular neck measurements in two groups of patients with complete 2- and 3-year follow-up. Design: This was a prospective study of postoperative, radiologic images. Setting: The study used a referral center, institutional practice, and ambulatory patients. Subjects: From January 1994 until May 1998, 37 endografts were implanted for abdominal aortic aneurysm. In the first postoperative year, there were four unrelated deaths and six conversions, leaving 27 patients with complete 24-month data and 13 with complete 36-month data. Main Outcome Measure: Computed tomography angiograms were processed on a work station to measure the neck perpendicular to the central lumen line of the aorta. The surface area at the proximal endovascular anastomosis was recorded at each follow-up interval and related to the postoperative size at the same level. Results: Significant dilatation of the surface area was found: 20% (16% to 27%) at 24 months (c2 = 30; P < .001, Friedman) and 23% (18% to 28%) at 36 months (c2 = 27; P < .001, Friedman). This increase in neck size was continuous and linear, with a yearly rate of approximately 10% surface area; translated into diameter, this approximates 1 mm/y. Conclusion: A continuous aortic enlargement of approximately 1 mm/y at the level of the proximal endovascular anastomosis was found. Because of the practice of oversizing the endograft relative to the infrarenal aortic neck, a loss of the endovascular seal may not become apparent until several years after endovascular abdominal aortic aneurysm repair is performed. (J Vasc Surg 2001;33:S64-9.)

Purpose: This open single-center prospective study aimed to determine the redistribution of blood flow within the circle of Willis and through collateral pathways after carotid endarterectomy. Blood flow velocity and flow direction in the major cerebral arteries were determined, both at rest and during CO2 inhalation. Methods: Carotid endarterectomy was performed in 148 patients with a 70% or greater diameter stenosis of the internal carotid artery while patients were under general anesthesia. Arteriotomy closure was done with a venous patch. Selective shunting was performed with an electroencephalogram. Baseline blood flow velocity of the basal cerebral arteries was measured by means of transcranial Doppler sonography preoperatively (within 1 week before surgery) and 3 months postoperatively. At the same times, cerebrovascular reactivity was calculated during CO2 inhalation insonating both middle cerebral arteries. Results: Baseline blood flow velocity in the ipsilateral middle cerebral artery hardly changed 3 months postoperatively, but there was a considerable redistribution of flow in the circle of Willis. This was characterized by a decrease in contribution from the contralateral hemisphere through the anterior communicating artery, reduced cerebropetal flow rates in the ophthalmic artery, and smaller contribution of the posterior collateral sources. The CO2 reactivity on the side of surgery increased in all patients. In patients with a contralateral occlusion, CO2 reactivity increased on both sides. The redistribution of flow was most pronounced in patients who needed intraoperawtive shunting and in patients with a contralateral internal carotid artery occlusion. Conclusion: After carotid endarterectomy, flow redistribution, as expressed by changes in blood flow velocity values, occurs in the circle of Willis. The contribution of collateral sources is diminished, and the CO2 reactivity increases, both of which reflect improvement of the hemodynamic condition. The most improvement occurs in patients with contralateral occlusion. (J Vasc Surg 2001;33:139-47.)

Background: follow-up after endovascular abdominal aortic aneurysm repair (EAR) generally consists of serial diameter measurements. A size change after EAR, however, is the consequence of alterations of the excluded aneurysm sac volume. Objective: to assess the agreement between diameter measurements and volume measurements after endovascular aneurysm repair. Patients and methods: from 53 consecutive patients scheduled for EAR, follow-up of at least 6 months was available in 35 patients. CTA was performed on all patients at discharge, at 6 months and yearly thereafter. The resulting 113 datasets were processed on a workstation in a blinded and random order. Maximal aneurysm diameter (DMAX) was measured along the central lumen line. Total aneurysm volume was measured by manual segmentation. All measurements of an individual patient were compared with each other, resulting in 149 comparisons. The significance of individual size changes was classified based on the 95% confidence limits of the intra-observer variability, using difference-of-means analysis. DMAX changes were compared to volume changes. Results: in 37% of the comparisons, discordance was found between DMAX and volume measurements. A decrease in aneurysm size was missed using DMAX in 14% of cases and an increase in 19% of cases.Conclusion : aneurysm size changes after EAR are not noticed using maximal diameter measurements in over one-third of cases.

To evaluate whether and to what extent greater number of projection images obtained at three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography versus conventional digital subtraction angiography (DSA) causes overestimation of internal carotid arterial (ICA) stenosis.DSA (two or three projections), rotational angiography (16 or 32 projections), and 3D TOF MR angiography (12 projections) were performed in 47 stenotic ICAs of 38 symptomatic patients. Two observers independently measured maximum stenosis, and the mean differences among MR angiography, DSA, and rotational angiography were compared.Three rotational and five MR angiograms were nondiagnostic. Seven MR angiograms of ICA stenoses showed a signal void and were excluded from analysis. On the remaining 32 angiograms, mean differences in maximum stenosis for observers 1 and 2, respectively, were 7% (95% CI: 3%, 12%) and 8% (95% CI: 3%, 13%) at MR angiography versus DSA and 2% (95% CI: -2%, 7%) and -1% (95% CI: -5%, 3%) at MR angiography versus rotational angiography. ICA stenosis was graded significantly higher at MR angiography versus DSA, whereas, it was not overestimated at MR angiography versus rotational angiography. The difference in maximum stenosis at MR angiography versus DSA was significantly different from that of MR angiography versus rotational angiography.Apparent overestimation of ICA stenosis at 3D TOF MR angiography versus conventional DSA may be partly explained by the greater number of projection images available at 3D TOF MR angiography.

Objectives: to analyse whether preoperative transcranial Doppler (TCD) variables can predict intraoperative shunt requirement. Design and methods: the blood-flow velocity (BFV) in the major basal cerebral arteries was measured preoperatively with TCD, in 178 patients scheduled for CEA. Carotid artery compression and CO2 reactivity tests were also performed. Intraoperative electroencephalography was used to decide whether a shunt was needed. Differences in the probability of shunt requirement between the categories of variables were assessed with crosstabs statistics. Results: preoperative TCD criteria clearly identified a subgroup of 59 patients (33%) who did not require a shunt. In general, these patients appeared to have adequate collateral flow through the anterior communicating artery. In contrast, prediction of the need for a shunt was less reliable. TCD variables could predict the need for a shunt with a probability of only 60%. Conclusions: preoperative TCD can be used to identify patients who do not require a shunt during carotid endarterectomy.

PURPOSE: To assess how often rotational angiography depicts more severe internal carotid arterial stenosis compared with conventional intraarterial digital subtraction angiography (DSA) in two or three projections and how frequently this factor may affect patient treatment. MATERIALS AND METHODS: Rotational angiography (16 or 32 projections) was performed in addition to DSA in 47 stenotic internal carotid arteries (ICAs) in 38 symptomatic patients. ICA stenosis was measured independently at DSA and at rotational angiography with North American Symptomatic Carotid Endarterectomy Trial criteria. The degree of stenosis was categorized as 0%-29%, 30%-49%, 50%-69%, or 70%-99%. RESULTS: In three ICAs, rotational angiography was nondiagnostic. In 28 of the remaining 44 ICAs, the degree of stenosis was categorized similarly with DSA and rotational angiography, whereas with rotational angiography, 15 ICAs were classified one category higher and one ICA was classified two categories higher, owing to the increased number of projections available. Seventy percent to 99% stenosis was demonstrated in 18 ICAs with DSA and in 25 ICAs with rotational angiography. Thus, rotational angiography could have facilitated a change in the optimal treatment (from nonsurgical treatment to carotid arterial endarterectomy) in seven ICAs. CONCLUSION: Compared with DSA in two or three projections, rotational angiography frequently depicts more severe ICA stenosis. This indicates a limitation of DSA in depicting the maximum ICA stenosis.

Purpose: The prevalence of asymptomatic internal carotid artery stenosis (ICAS) in patients with peripheral arterial disease (PAD) and characteristics that are associated with ICAS were studied. Methods: We used data from the first 600 patients enrolled in the Second Manifestations of ARTerial disease (SMART) study, a single-center, prospective cohort study among patients referred with a manifestation of cardiovascular disease, diabetes mellitus, hypertension, or hyperlipidemia. Included in the analysis were 162 patients with PAD or a history of PAD, who were not known to have ICAS at the time of referral and who had no history of cerebrovascular symptoms or previous carotid endarterectomy. ICAS was detected with duplex scanning and defined as a peak systolic velocity more than 150 cm/s (diameter reduction 50% or higher) on at least one side. Cardiovascular risk factors were measured. Logistic regression analysis was performed to investigate associations between these characteristics and ICAS. Results: The prevalence of previously unknown ICAS was 14%. A patient age of 67 years or older, body weight of 68 kg or less, and diastolic blood pressure of 75 mm Hg or lower were independently associated with ICAS. The Prevalence Of Icas In Patients With One Of These Characteristics (38% Of The Patients) Was 8%, In Those With Two Characteristics (21% Of The Patients) Was 32%, And In Those With Three Characteristics (6% Of The Patients) Was 50%. Conclusions: The prevalence of ICAS increases as much as 50% in patients who have PAD and the risk indicators of an age of 67 years or older, a body weight of 68 kg or less, and a diastolic blood pressure of 75 mm Hg or lower, and, therefore, these characteristics may be used as a means of increasing the likelihood of detecting ICAS. (J Vasc Surg 1999;30:519-25.)

Objectives:to compare the clinical outcome ofin situand reversed bypass grafting.Design:multicentre, prospective, non-randomised study.Patients and methods:five-hundred patients with anin situgraft and 955 patients with a reversed graft were compared regarding graft occlusion, the need for graft revision, and limb salvage.Results:two-year assisted primary patency of femoropopliteal bypass procedures was 82% forin situand 82% for reversed grafts. The corresponding hazard ratio (HR) for occlusion was 1.27 (95% CI 0.91–1.77). The 2-year assisted primary patency of femorocrural bypass procedures was 69% forin situvs. 70% for reversed grafts. The corresponding HR was 1.13 (95% CI 0.73–1.75). Adjustment for relevant baseline variables did not change the results. More reinterventions were needed to maintain integrity and patency of thein situgraft especially in crural bypasses. No differences in limb salvage rates were seen.Conclusions:reversed andin situvein grafts have similar patency and limb salvage rates for both femoropopliteal and femorocrural bypass procedures. Thein situgraft needs more secondary interventions.

We attempted to assess whether magnetic resonance imaging (MRI)-MR angiography (MRA)-MR spectroscopy (MRS) measurements can be used in the differentiation of patients in whom severe carotid lesions result in chronically hypoperfused regions and in whom the collateral capacity is sufficient to maintain a normal cerebral blood flow. Sixty-six patients with severe stenosis of the internal carotid artery (ICA) and 19 control subjects underwent MRI, 1H MRS, and MRA. Anaerobic metabolic changes in the middle cerebral artery (MCA) territory were studied by assessing N-acetyl-L-aspartate (NAA)/choline and lactate/NAA ratios. Quantitative flow was measured in the ICA, in the basilar artery, and in the MCA. Thirty-four patients had borderzone infarcts, 16 patients had territory infarcts, and 16 patients had no infarcts on MRI. Patients with borderzone infarcts had significantly reduced flow in the ICA (P < 0.001) and in the MCA (P < 0.05) and decreased NAA/choline ratios (P < 0.001) in non-infarcted regions compared with control subjects (P < 0.001) but also compared with patients with territory infarcts (P < 0.05) and patients without infarcts (P < 0.05). Flow measurements in the ICA and MCA and metabolic measurements in the MCA territory can be applied to select patients in whom cerebral perfusion pressure is insufficient to maintain normal cellular integrity. J. Magn. Reson. Imaging 1999;9:1–9 © 1999 Wiley-Liss, Inc.

Background and Purpose —Two surgical trials established that carotid endarterectomy is beneficial to symptomatic patients who have a severe internal carotid artery (ICA) stenosis on angiograms. Duplex ultrasonography–derived hemodynamic parameters show a good correlation with angiography and are often used for detecting severe ICA stenoses. However, duplex performance is ultrasound machine and operator dependent. Over time both may change, possibly affecting duplex performance. We compared duplex performance of 2 time periods in 1 specific vascular laboratory using angiography as the gold standard. Methods —Consecutive patients who underwent both angiography and duplex examinations of the ICA were evaluated (first period, 60 patients; second period, 61 patients). Peak systolic velocity and several other hemodynamic parameters and ratios were analyzed by receiver operating characteristic curves in their ability to detect severe ICA stenoses. The optimal parameter and threshold were determined for each period. Subsequently, duplex test characteristics were compared after the optimal thresholds of both the first and the second periods were applied in the second period. Results —In both periods peak systolic velocity of the ICA was the best test parameter; areas under the receiver operating characteristic curve were similar (0.957 and 0.954, respectively). However, the optimal threshold was different. The optimal threshold in the second period was 270 cm/s. When the optimal threshold of 210 cm/s of the first period was applied in the second period, test characteristics changed significantly. Sensitivity increased from 98% to 100%, and specificity decreased from 85% to 71% ( P =0.004). Conclusions —The optimal threshold for detecting severe ICA stenoses with duplex ultrasonography in our laboratory changed over time. Individual laboratories should assess duplex accuracy regularly and adjust adopted criteria if necessary to keep diagnostic performance optimal.

Objectives: carotid endarterectomy (CEA) is intended to prevent stroke and therefore to extend lifespan. Whether CEA also influences health-related quality of life (HRQOL) is largely unknown. This study aimed to assess HRQOL-changes after CEA. Design: prospective study, data assessment within 1 week before and 3 months after CEA. Materials: patient classification ( n = 70) was based on presenting neurological symptoms (none (24), transient (26), or permanent (20)), patency or occlusion (27%) of the contralateral internal carotid artery and intraoperative shunt requirement (28%). Methods: HRQOL was investigated with the Sickness Impact Profile (SIP). Analysis of variance was used to adjust for the influence of preoperative differences in functional impairment and comorbidity on the changes found. Results: preoperative findings showed that the SIP scores of stroke patients and shunted patients were significantly higher (indicating poorer HRQOL) than those of the other patients. No adverse effect of CEA was observed. Analysis of variance revealed that neurological classification was not reflected to HRQOL changes. However, patients with contralateral occlusion showed a significant postoperative improvement ( f = 4.99, p Conclusions: HRQOL improvement after CEA is restricted to patients with occlusion of the contralateral carotid artery. Assessment of outcome of CEA should be related not only to neurological classification, but also to haemodynamic factors such as contralateral occlusion.

Aim: to investigate the relation between the number of preoperative patent side branches and the presence or absence of postoperative endoleaks, and to study the fate of patent branches after operation. Patients and Methods: thirty consecutive patients were included. Cine mode viewing of axial CT angiography images was applied to detect infrarenal aortic side branches. The position of side branches relative to the renal arteries, branch patency and run-off pathways were studied. Results: a total of 160 patent side branches were found. All patients had two or more patent side branches. A patent inferior mesenteric artery was found in 22/30 patients (73%). Postoperative CT scans revealed major endoleaks in five patients (16%) and minor endoleaks in eight (27%). There was no significant difference in the number of preoperative patent side branches in patients with a completely thrombosed aneurysm sac (five; range 2–8) compared to patients with postoperative endoleaks (six; range 3–9; p = 0.12). Backbleeding from patent side branches as the sole cause of endoleak was seen in one patient only (3.3%). Conclusion: postoperative endoleaks are not related to the number of preoperative patent side branches. In patients without endoleaks, contrast enhancement of side branches was repeatedly seen in the vicinity of the aneurysm wall. Although close follow-up of these branches is warranted, they did not affect the outcome of endovascular aneurysm repair.

Objective: To evaluate complications of standard elective repair of infrarenal abdominal aortic aneurysms. Design: Prospective multicentre study. Materials: Two-hundred and ninety-one consecutive patients undergoing standard elective surgery for an infrarenal aortic aneurysm. Methods: Recording adverse events according to the recommendations of the Ad Hoc Committee on Reporting Standards. Results: Seventy-five patients (26%) experienced some complication following elective aortic aneurysm surgery. Twenty-two patients had a mild complication (7.6%, 95% C.I. 4.8–11.2%), 27 a moderate (9.3%, 95% C.I. 6.2–13.2%) and 26 patients had a severe and/or fatal complication (8.9%, 95% C.I. 5.9–12.8%). The in-hospital mortality was 4.1% (12 patients, 95% C.I. 2.2–7.1%). Cardiac failure was the commonest primary cause for death (58%). Twenty-two per cent of the patients had a non-fatal complication: the most frequent being pulmonary (10%) and cardiac (10%). Patients with a history of cardiac events had a five times higher risk of a fatal outcome (95% C.I. 1.1–24.0) and a two and a half times higher risk of any severe fatal or non-fatal complication (95% C.I. 1.0–6.5). Other risk factors were advancing age and the presence of pulmonary disease. Conclusions: In addition to mortality, morbidity figures of standard aneurysm operations are important, as well as associated risk factors. This is especially true when evaluating early repair of small aneurysms and new endovascular techniques.

Summary Background Percutaneous transluminal angioplasty (PTA) is a safe, simple, and successful treatment for intermittent claudication caused by iliac-artery occlusive disease. Primary stent placement has been proposed as more effective than PTA. We compared the technical results and clinical outcomes of two treatment strategies—primary placement of a stent across the stenotic segment of the iliac artery, or primary PTA followed by selective stent placement when haemodynamic results were inadequate. Methods We randomly assigned 279 patients with intermittent claudication, recruited from departments of vascular surgery, either to direct stent placement (group I, n=143) or primary angioplasty (group II, n=136), with subsequent stent placement in case of a residual mean pressure gradient greater than 10 mm Hg across the treated site. The main inclusion criterion was intermittent claudication on the basis of iliac-artery stenosis of more than 50%, proven by angiography. All patients had a clinical assesment before intervention and at 3, 12, and 24 months. Clinical success was defined as improvement of at least one clinical category. Secondary endpoints were initial technical results, procedural complications, cumulative patency as assessed by duplex ultrasonography, and quality of life. Findings In group II, selective stent placement was done in 59 (43%) of the 136 patients. The mean follow-up was 9-3 months (range 3–24). Initial haemodynamic success and complication rates were 119 (81%) of 149 limbs and 6 (4%) of 143 limbs (group I) versus 103 (82%) of 126 limbs and 10 (7%) of 136 limbs (group II), respectively. Clinical success rates at 2 years were 29 (78%) of 37 patients and 26 (77%) of 34 patients in groups I and II, respectively (p=0-6); however, 43% and 35% of the patients, respectively, still had symptoms. Quality of life improved significantly after intervention (p Interpretation There were no substantial differences in technical results and clinical outcomes of the two treatment strategies both at short-term and long-term follow-up. Since angioplasty followed by selective stent placement is less expensive than direct placement of a stent, the former seems to be the treatment of choice for lifestyle-limiting intermittent claudication caused by iliac artery occlusive disease.

Objectives: To investigate the influence of mesothelial cell (MC) seeding on patency and neointimal formation of small diameter ePTFE grafts in a canine model. Materials and Methods: MC were isolated from the omentum, cultured, seeded on fibronectin-coated ePTFE grafts (4 cm, 4 mm ID), and implanted in the carotid artery of five Beagle dogs. Each dog also received a non-seeded control graft. Patency was assessed by palpation immediately after implantation, and non-invasively by magnetic resonance angiography (MRA) after 1 week and just prior to sacrifice (4 weeks). Intimal thickness was quantified on histological sections by use of computer-aided morphometry. Results: All grafts were patent after implantation. After 1 week, MRA showed the loss of lumen diameter in two seeded grafts. After 4 weeks, two seeded grafts were occluded, one seeded graft was severely stenosed, and all others were without angiographic lumen reduction. Histology and morphometry confirmed that two seeded grafts were occluded, and demonstrated that the other three seeded grafts showed significantly more intima formation (0.22–1.34 mm) than the control grafts ( p Conclusions: The MC seeding process decreases patency and increases neointimal formation of small diameter ePTFE grafts in dogs and does not seem to be useful for reduction of graft thrombogenicity.

MR elastography (MRE) can serve as an accurate surrogate marker of liver fibrosis. For any diagnostic test that is to replace the current reference standard, interobserver agreement should be at least as good and preferably better. The objective of this study was to perform a head-to-head comparison of the interobserver agreements of MRE and liver fibrosis staging on biopsy in a single cohort of hepatitis patients. One hundred and three patients with viral hepatitis B or C who had a liver biopsy underwent MRE. Two readers independently selected a region-of-interest (ROI) in the liver to derive elasticity values. Two pathologists first independently staged fibrosis on biopsies using the METAVIR classification and subsequently held a consensus meeting. Interobserver agreements of elasticity values and fibrosis stages were assessed with intraclass correlation coefficients (ICC). MRE and biopsy data were available for 85/103 patients. ICC of pathologists staging fibrosis was almost perfect at 0.91 (95% CI 0.86-0.94). ICC for MRE readers was significantly (P < 0.0001) higher at 0.99 (95% CI 0.98-1.00). Interobserver agreement for liver fibrosis staging was almost perfect for both histopathology and MRE, with a significant higher agreement for MRE. Its high interobserver agreement and reliable accuracy support the use of MRE as a non-invasive screening tool for liver fibrosis.

Objective To compare the diagnostic accuracy of TE and MRE and establish cutoff levels and diagnostic strategies for both techniques, enabling selection of patients for liver biopsy. Methods One hundred three patients with chronic hepatitis B or C and liver biopsy were prospectively included. Areas under curves (AUROC) were compared for TE and MRE for METAVIR fibrosis grade >= F2 and >= F3. We defined cutoff values for selection of patients with F0-F1 (sensitivity >95%) and for significant fibrosis F2-F4 (specificity >95 %). Results Following exclusions, 85 patients were analysed (65 CHB, 19 CHC, 1 co-infected). Fibrosis stages were F0 (n = 3), F1 (n = 53), F2 (n = 15), F3 (n = 8) and F4 (n = 6). TE and MRE accuracy were comparable [AUROC(TE)>= F2: 0.914 (95 % CI: 0.857-0.972) vs. AUROC(MRE)>= F2: 0.909 (0.840-0.977), P = 0.89; AUROC(TE)>= F3: 0.895 (0.816-0.974) vs. AUROC(MRE)>= F3: 0.928 (0.874-0.982), P = 0.42]. Cutoff values of = 8.9 kPa (TE) and = 2.18 kPa (MRE) diagnosed 64 % and 66 % of patients correctly as F0-F1 or F2-F4. A conditional strategy in inconclusive test results increased diagnostic yield to 80 %. Conclusion TE and MRE have comparable accuracy for detecting significant fibrosis, which was reliably detected or excluded in two-thirds of patients. A conditional strategy further increased diagnostic yield to 80 %. Key Points Both ultrasound-based transient elastography and magnetic resonance elastography can assess hepatic fibrosis. Both have comparable accuracy for detecting liver fibrosis in viral hepatitis. The individual techniques reliably detect or exclude significant liver fibrosis in 66 %. A conditional strategy for inconclusive findings increases the number of correct diagnoses.

OBJECTIVES: Intra-arterial pressure measurement is considered the "gold standard" for the haemodynamic evaluation of aortoiliac lesions. When compared to pressure measurement duplex scanning fails to detect some of the haemodynamically significant lesions. To improve the assessment of the haemodynamic significance of these lesions by duplex scanning, the flow-related duplex parameters delta PSV and EDV at rest and after exercise were compared with intra-arterial pressure gradients before and during increased blood flow. PATIENTS AND METHODS: Forty-five aortoiliac segments with an isolated stenosis were studied prospectively. Doppler samples were taken at the site of the stenosis both at rest and after exercise on a bicycle ergometer, followed by intraarterial pressure measurement at rest and during pharmacologically induced increased blood flow. RESULTS: At rest a delta PSV (delta PSVr) of 1.6 m/s showed a sensitivity and specificity of 85% and 88%, respectively. After exercise a delta PSV (delta PSVe) of 1.6 m/s showed a sensitivity of 100% at the cost of only a slight reduction in specificity when compared to delta PSVr. The end diastolic velocity at rest (EDVr) had only limited clinical value. The EDV after exercise (EDVe) provided important information if the velocity was 0.5 m/s or lower or if the velocity was 1.6 m/s or greater. CONCLUSION: The delta PSV and the EDV after exercise can be of value in the assessment of the haemodynamic significance of aortoiliac stenoses