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Background & Aims: The diagnosis of chronic gastrointestinal ischemia (CGI) remains a clinical challenge. We aimed to assess the diagnostic value of clinical features, visualization of the gastrointestinal arteries, and evaluation of mucosal perfusion in patients clinically suspected of CGI., Methods: A total of 186 patients referred for suspicion of CGI were prospectively included and followed up. All patients had an extensive diagnostic work-up, including visualization of the gastrointestinal arteries with computed tomography, magnetic resonance, or conventional angiography, and mucosal perfusion with tonometry. The reference standard for CGI was persistent clinical response after adequate therapy. The diagnostic value of individual and combined tests was assessed with multivariable logistic regression analysis., Results: A total of 116 (62%) patients were diagnosed with CGI. In a multivariable model solely based on clinical features, the strongest predictors for CGI were the presence of postprandial pain, weight loss per month in kilograms, concomitant cardiovascular disease, and presence of an abdominal bruit. However, this model showed limited discriminative ability for the presence or absence of CGI (c-statistic, 0.62). Adding radiologic imaging to the prediction model improved the discriminative ability substantially (c-statistic, 0.81). Adding tonometry to the prediction model further improved the discriminative ability of the model (c-statistic, 0.90). The combination of clinical features and tonometry with a c-statistic of 0.88 approximated the discriminative ability of the latter model., Conclusions: Clinical features alone have a limited value to assess CGI correctly. Visualization of the gastrointestinal arteries and evaluation of mucosal perfusion substantially improve the diagnosis of CGI. The strongest diagnostic contribution comes from mucosal perfusion assessment., (Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.)

The classical triad of postprandial pain, weight loss and an abdominal bruit is thought to be the most common presentation of chronic gastrointestinal ischaemia. We describe a patient with severe diarrhoea as an uncommon presenting symptom of small bowel ischaemia, suggesting a mesenteric steal phenomenon due to a significant atherosclerotic coeliac artery stenosis. The stenosis and concomitant steal effect was successfully treated by stent placement. The latter is supported by the patient's uneventful course after stent placement. This case illustrates that chronic gastrointestinal ischaemia has to be considered in patients with otherwise unexplained diarrhoea.

Background: The optimal first-line treatment for intermittent claudication is currently unclear., Objective: To compare the cost-effectiveness of endovascular revascularization vs supervised hospital-based exercise in patients with intermittent claudication during a 12-month follow-up period., Design: Randomized controlled trial with patient recruitment between September 2002-September 2006 and a 12-month follow-up per patient., Setting: A large community hospital., Participants: Patients with symptoms of intermittent claudication due to an iliac or femoro-popliteal arterial lesion (293) who fulfilled the inclusion criteria (151) were recruited. Excluded were, for example, patients with lesions unsuitable for revascularization (iliac or femoropopliteal TASC-type D and some TASC type-B/C., Intervention: Participants were randomly assigned to endovascular revascularization (76 patients) or supervised hospital-based exercise (75 patients)., Measurements: Mean improvement of health-related quality-of-life and functional capacity over a 12-month period, cumulative 12-month costs, and incremental costs per quality-adjusted life year (QALY) were assessed from the societal perspective., Results: In the endovascular revascularization group, 73% (55 patients) had iliac disease vs 27% (20 patients) femoral disease. Stents were used in 46/71 iliac lesions (34 patients) and in 20/40 femoral lesions (16 patients). In the supervised hospital-based exercise group, 68% (51 patients) had iliac disease vs 32% (24 patients) with femoral disease. There was a non-significant difference in the adjusted 6- and 12-month EuroQol, rating scale, and SF36-physical functioning values between the treatment groups. The gain in total mean QALYs accumulated during 12 months, adjusted for baseline values, was not statistically different between the groups (mean difference revascularization versus exercise 0.01; 99% CI -0.05, 0.07; P = .73). The total mean cumulative costs per patient was significantly higher in the revascularization group (mean difference euro2318; 99% CI 2130 euros, 2506 euros; P < .001) and the incremental cost per QALY was 231 800 euro/QALY adjusted for the baseline variables. One-way sensitivity analysis demonstrated improved effectiveness after revascularization (mean difference 0.03; CI 0.02, 0.05; P < .001), making the incremental costs 75 208 euro/QALY., Conclusion: In conclusion, there was no significant difference in effectiveness between endovascular revascularization compared to supervised hospital-based exercise during 12-months follow-up, any gains with endovascular revascularization found were non-significant, and endovascular revascularization costs more than the generally accepted threshold willingness-to-pay value, which favors exercise.

Objectives: To assess the clinical condition at mid-to-late follow-up in tetralogy of Fallot corrected by a transatrial-transpulmonary approach at a young age and to identify risk factors associated with right ventricular dilation/dysfunction and with decreased exercise tolerance., Methods: Patients with tetralogy of Fallot underwent cardiac magnetic resonance imaging, maximal bicycle ergometry, electrocardiography, Holter monitoring, and spirometry. Multivariate linear regression analyses were used to determine independent predictors for selected clinical parameters., Results: Fifty-nine patients (mean +/- SD), age at repair 0.9 +/- 0.5 years, interval since repair 14 +/- 5 years, were included. The median pulmonary regurgitant fraction was 32% (0%-57%). Compared with published data on healthy controls, Fallot patients had significantly larger right ventricular end-diastolic and end-systolic volumes and smaller right ventricular and left ventricular ejection fractions. Maximum oxygen consumption was 97% +/- 17% and maximum workload 89% +/- 13% of predicted. Median QRS duration was 110 ms (82-161 ms). No important ventricular arrhythmias were found. Compared with patients without a transannular patch, patients with a patch had more pulmonary regurgitation, a larger right ventricle, worse right ventricular and left ventricular ejection fractions, but comparable exercise capacity. Multivariate regression analysis identified the following independent determinants for larger right ventricular volumes: longer interval since repair, longer QRS duration, and higher pulmonary regurgitation percentage. The following were independent determinants for smaller right ventricular ejection fraction: abnormal right ventricular outflow tract wall motion, longer interval since repair, and longer QRS duration. For smaller maximum oxygen consumption, the independent determinants were smaller right ventricular ejection fraction and longer QRS duration., Conclusions: At mid-to-late follow-up, clinical condition in tetralogy of Fallot corrected according to contemporary surgical approaches appears well preserved. However, even these patients show right ventricular dilation and dysfunction associated with impaired functional capacity. Abnormalities relate to right ventricular outflow tract motion abnormalities, longer interval since repair, longer QRS duration, and more severe pulmonary regurgitation.

Purpose: To evaluate the accuracy, predictive value, and observer agreement of the duplex ultrasound waveform at the common femoral artery as a marker of significant aortoiliac disease in a large group of consecutive patients who underwent a diagnostic workup for peripheral arterial disease in a vascular unit., Methods: In 191 consecutive patients (381 aortoiliac segments), we classified the duplex ultrasound waveform at the common femoral artery as triphasic, biphasic, sharp monophasic, or poor monophasic. The waveforms were then compared with the findings of magnetic resonance angiography of the aortoiliac segment and peripheral runoff vessels. We calculated the diagnostic accuracy of the duplex waveform for detecting >50% obstructive disease of the aortoiliac segment and determined the observer agreement for classifying the duplex waveforms done by two independent observers., Results: Magnetic resonance angiography showed obstruction in 152 (39.9%) of 381 aortoiliac segments in 191 patients. The presence of a poor monophasic waveform, encountered in 91 (24.3%) of 375 segments, was a reliable sign of significant aortoiliac disease, with a positive predictive value of 92%. Other waveforms were nondiagnostic for aortoiliac obstructive disease. The sharp monophasic waveform reliably predicted occlusive disease of the superficial femoral artery that was seen in 17 of 23 instances. There was good observer agreement for classifying duplex waveforms (kappa(w)= 0.85; 95% confidence interval, 0.80 to 0.89)., Conclusion: The poor monophasic duplex waveform at the common femoral artery is in itself an accurate marker of aortoiliac obstructive disease. Other waveforms are nondiagnostic for aortoiliac disease.

Background and Purpose: Besides the severity of carotid artery stenosis, atherosclerotic plaque composition is an important determinant of cerebral symptoms. We analyzed the relationship between the composition of the atherosclerotic plaque at the carotid artery bifurcation and ipsilateral ischemic cerebral lesions on MR imaging., Methods: Forty-one patients with symptomatic carotid artery stenosis (>70%) underwent black-blood, fast spin-echo imaging of the carotid artery and turbo fluid-attenuated inversion recovery (t-FLAIR) imaging of the brain. Plaque regions with a relative decrease in signal intensity in the plaque from proton density-weighted (TE = 14 ms) to T2-weighted (TE = 50 ms) imaging were considered to be lipid cores. We assessed the number and location of infarcts in the ipsilateral cortex, basal ganglia, and centrum semiovale, and hyperintense white matter lesions on t-FLAIR images., Results: Lipid in the atherosclerotic plaque at the carotid bifurcation was seen in 25 patients. Ipsilateral infarctions were seen in 22 (54%); most often, it involved the centrum semiovale. Patients with a lipid core had an ipsilateral infarct more often than patients without a lipid core (68% vs. 31%; P = .03). Centrum semiovale infarcts were more frequent (56% vs. 25%, P = .06) and the median number of centrum semiovale infarcts was higher P = .04) in patients with a lipid core than in patients without a lipid core., Conclusion: Ischemic cerebral lesions were common in patients with symptomatic carotid artery disease. Plaque composition, as assessed with MR imaging, is related to the presence and extent of ischemic cerebral lesions.

Background: The patency of arteriovenous (AV) expanded polytetrafluoroethylene (ePTFE) hemodialysis grafts is severely compromised by intimal hyperplasia (IH) at the venous anastomosis and in the venous outflow tract. We addressed the potential of primary placement of a sirolimus-eluting stent (SES) in a validated porcine model., Methods and Results: In 25 pigs, ePTFE AV grafts were created bilaterally between the carotid artery and the jugular vein, whereupon a self-expandable nitinol stent (14 SESs and 11 bare-metal stents) was implanted over the venous anastomosis in 1 of the 2 grafts. After exclusion of technical failures and 1 unilateral occlusion, 16 pigs (9 SESs and 7 bare-metal stents) were included for further analysis. After 28 days, we measured graft flow and performed quantitative angiography. The pigs were then euthanized, and grafts with adjacent vessels were excised for histological analysis. Minimal luminal diameter was substantially larger in the SES group compared with unstented controls (5.9+/-0.2 versus 3.8+/-0.4 mm, respectively, P=0.01), which was accompanied by more prominent graft flow (SES, 1360+/-89 mL/min versus unstented, 861+/-83 mL/min, P=0.05). IH at the venous anastomosis was 77% less in the SES group compared with unstented controls (0.44+/-0.05 versus 1.92+/-0.5 mm2, respectively, P=0.01), whereas IH increased markedly when bare-metal stents were used (5.7+/-1.4 mm2, P=0.05)., Conclusions: SESs in the venous outflow of AV grafts significantly reduce IH and increase vessel diameter and graft flow compared with unstented grafts. These findings suggest that SESs have the potential to improve primary patency of AV grafts in hemodialysis patients.

Hemodialysis (HD) access complications constitute a major cause of morbidity in HD patients. The failure of HD access grafts is predominantly due to progressive intimal hyperplasia (IH) at the venous anastomosis, resulting in a graft flow decline, which ultimately gives rise to graft thrombosis. To date, all tested pharmacological and surgical interventions have not resulted in increased arteriovenous (AV) graft patency rates in HD patients. In this review, we address the mechanisms contributing to AV graft failure and discuss several "emerging" strategies, which could hold promise for optimizing AV graft patency rates. In view of the failure of systemic therapies and the predictable localization of IH, local therapeutic strategies comprise the most promising interventions to improve AV graft patency rates. Based on the large number of promising candidates including drug-eluting stents and brachytherapy, the unmet clinical need for AV graft failure in HD patients is likely to be revisited in the very near future. The biggest challenge, however, remains to translate basic experimental findings into clinical benefits. Simultaneously, continuous efforts should be undertaken to increase the percentage of patients utilizing AV fistulas, which remains the best form of permanent vascular access (VA) for HD.

Objectives: This study was designed to prospectively evaluate the diagnostic performance of multislice spiral computed tomography (MSCT) coronary angiography for the detection of significant lesions in all segments of the coronary tree potentially suitable for revascularization., Background: Noninvasive MSCT coronary angiography is a promising coronary imaging technique., Methods: Sixteen-row MSCT coronary angiography was performed in 128 patients (89% men, mean age 58.9 +/- 11.7 years) in sinus rhythm with stable angina pectoris scheduled for conventional coronary angiography. Sixty percent (77 of 128) of patients received pre-scan oral beta-blockers, resulting in a mean heart rate of 57.7 +/- 7.7 beats/min. The diagnostic performance of MSCT for detection of significant lesions (> or =50% diameter reduction) was compared with that of quantitative coronary angiography (QCA)., Results: The sensitivity of MSCT for detection of significant lesions was 92% (216 of 234, 95% confidence interval [CI]: 88 to 95). Specificity was 95% (1,092 of 1,150, 95% CI: 93 to 96), positive predictive value 79% (216 of 274, 95% CI: 73 to 88), and negative predictive value 98% (1,092 of 1,110, 95% CI: 97 to 99). Two > or =50% lesions were missed because of motion artifacts and two because of severe coronary calcifications. The rest (78%, 14 of 18) were detected but incorrectly classified as <50% obstructions. All patients with and 86% (18 of 21) of patients without significant lesions on QCA were correctly classified by MSCT. All patients with significant left main disease or total occlusions were correctly identified on MSCT., Conclusions: Sixteen-row MSCT coronary angiography permits reliable detection of significant obstructive coronary artery disease in patients with stable angina in sinus rhythm.

Magnetic resonance (MR) acoustic scanner noise may negatively affect the performance of functional magnetic resonance imaging (fMRI), a problem that worsens at the higher field strengths proposed to enhance fMRI. We present an overview of the current knowledge on the effects of confounding acoustic MR noise in fMRI experiments. The principles and effectiveness of various methods to reduce acoustic noise in fMRI are discussed, practical considerations are addressed and recommendations are made., (Copyright 2003 Wiley-Liss, Inc.)

Background: This study examined the effects of stent placement for renal artery stenosis on the function of treated and contralateral kidneys., Methods: Eighteen patients who underwent stent placement for unilateral renal artery stenosis presenting with hypertension and/or renal failure were studied before angiography and stent placement and at their one-year follow-up. Renal vein blood samples were taken at both sides, at each side simultaneously with a sample from the aorta, to measure the plasma renin concentration and the concentrations of 131I-hippuran and 125I-thalamate during constant systemic infusion of these radiochemicals. This allowed an assessment of the single-kidney contributions to the total renin secretion, effective renal plasma flow (131I-hippuran clearance) and glomerular filtration rate (125I-thalamate clearance)., Results: At the one-year follow-up, the vein-to-artery renin ratio at the treated side had decreased to normal, from 1.65 +/- 0.131 to 1.23 +/- 0.076 (mean +/- SEM; P = 0.011), indicating an improved renal blood flow. Contralaterally it rose from 1.09 +/- 0.042 to 1.17 +/- 0.029 (P = 0.055) at follow-up. The extraction ratio of 131I-hippuran improved at the treated side (0.48 +/- 0.049 to 0.62 +/- 0.034; P = 0.003) and contralaterally (0.67 +/- 0.033 to 0.73 +/- 0.026; P = 0.043). The extraction ratio of 125I-thalamate, which equals filtration fraction, improved at both sides (0.12 +/- 0.014 to 0.17 +/- 0.012 at the treated side, P = 0.001; 0.18 +/- 0.013 to 0.22 +/- 0.011 contralaterally, P = 0.002). Two-kidney effective renal blood flow and glomerular filtration rate remained unchanged., Conclusion: Renal artery stenting was capable of causing improvement of glomerular filtration rate of the treated kidney, although the overall glomerular filtration rate did not change.