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- Lee, Byung-Boong, et al.
(författare)
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Venous hemodynamic changes in lower limb venous disease : the UIP consensus according to scientific evidence
- 2016
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Ingår i: International Journal of Angiology. - : Springer. - 0392-9590 .- 1827-1839. ; 35:3, s. 236-352
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Tidskriftsartikel (refereegranskat)abstract
- There are excellent guidelines for clinicians to manage venous diseases but few reviews to assess their hemodynamic background. Hemodynamic concepts that evolved in the past have largely remained unchallenged in recent decades, perhaps due to their often complicated nature and in part due to emergence of new diagnostic techniques. Duplex ultrasound scanning and other imaging techniques which evolved in the latter part of the 20th century have dominated investigation. They have greatly improved our understanding of the anatomical patterns of venous reflux and obstruction. However, they do not provide the physiological basis for understanding the hemodynamics of flow, pressure, compliance and resistance. Hemodynamic investigations appear to provide a better correlation with post-treatment clinical outcome and quality of life than ultrasound findings. There is a far better prospect for understanding the complete picture of the patient's disability and response to management by combining ultrasound with hemodynamic studies. Accordingly, at the instigation of Dr Angelo Scuderi, the Union Internationale de Phlebologie (UIP) executive board commissioned a large number of experts to assess all aspects of management for venous disease by evidence-based principles. These included experts from various member societies including the European Venous Forum (EVF), American Venous Forum (AVF), American College of Phlebology (ACP) and Cardiovascular Disease Educational and Research Trust (CDERT). Their aim was to confirm or dispel long-held hemodynamic principles and to provide a comprehensive review of venous hemodynamic concepts underlying the pathophysiology of lower limb venous disorders, their usefulness for investigating patients and the relevant hemodynamic changes associated with various forms of treatment. Chapter 1 is devoted to basic hemodynamic concepts and normal venous physiology. Chapter 2 presents the mechanism and magnitude of hemodynamic changes in acute deep vein thrombosis indicating their pathophysiological and clinical significance. Chapter 3 describes the hemodynamic changes that occur in different classes of chronic venous disease and their relation to the anatomic extent of disease in the macrocirculation and microcirculation. The next four chapters (Chapters 4-7) describe the hemodynamic changes resulting from treatment by compression using different materials, intermittent compression devices, pharmacological agents and finally surgical or endovenous ablation. Chapter 8 discusses the unique hemodynamic features associated with alternative treatment techniques used by the CHIVA and ASVAL. Chapter 9 describes the hemodynamic effects following treatment to relieve pelvic reflux and obstruction. Finally, Chapter 10 demonstrates that contrary to general belief there is a moderate to good correlation between certain hemodynamic measurements and clinical severity of chronic venous disease. The authors believe that this document will be a timely asset to both clinicians and researchers alike. It is directed towards surgeons and physicians who are anxious to incorporate the conclusions of research into their daily practice. It is also directed to postgraduate trainees, vascular technologists and bioengineers, particularly to help them understand the hemodynamic background to pathophysiology, investigations and treatment of patients with venous disorders. Hopefully it will be a platform for those who would like to embark on new research in the field of venous disease.
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- Lurie, Fedor, et al.
(författare)
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Multicenter assessment of venous reflux by duplex ultrasound
- 2012
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 1097-6809 .- 0741-5214. ; 55:2, s. 437-445
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This prospective multicenter investigation was conducted to define the repeatability of duplex-based identification of venous reflux and the relative effect of key parameters on the reproducibility of the test. Methods: Repeatability was studied by having the same technologist perform duplicate tests, at the same time of the day, using the same reflux-provoking maneuver and with the patient in the same position. Reproducibility was examined by having two different technologists perform the test at the same time of the day, using the same reflux-provoking maneuver and with the patient in the same position. Facilitated reproducibility was studied by having two different technologists examine the same patients immediately after an educational intervention. Limits of agreement between two duplex scans were studied by changing three elements of the test: time of the day (morning vs afternoon), patient's position (standing vs supine), and reflux initiation (manual vs automatic compression decompression). Results: The study enrolled 17 healthy volunteers and 57 patients with primary chronic venous disease. Repeatability of reflux time measurements in deep veins did not significantly differ with the time of day, the patient's position, or the reflux-provoking maneuver. Reflux measurements in the superficial veins were more repeatable (P < .05) when performed in the morning with the patient standing. The agreement between the clinical interpretations significantly depended on a selected cut point (Spearman's rho, -0.4; P < .01). Interpretations agreed in 93.4% of the replicated measurements when a 0.5-second cut point was selected. The training intervention improved the frequency of agreement to 94.4% (kappa = 0.9). Alternations of the time of the duplex scan, the patient's position, and the reflux-provoking maneuver significantly decreased reliability. Conclusions: This study provides evidence to develop a new standard for duplex ultrasound detection of venous reflux. Reports should include information on the time of the test, the patient's position, and the provoking maneuver used. Adopting a uniform cut point of 0.5 second for pathologic reflux can significantly improve the reliability of reflux detection. Implementation of a standard protocol should elevate the minimal standard for agreement between repeated tests from the current 70% to at least 80% and with more rigid standardization, to 90%. (J Vase Surg 2012;55:437-45.)
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- Nchimi, Alain, et al.
(författare)
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Multifactorial Relationship Between F-18-Fluoro-Deoxy-Glucose Positron Emission Tomography Signaling and Biomechanical Properties in Unruptured Aortic Aneurysms
- 2014
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Ingår i: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 7:1, s. 82-91
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Tidskriftsartikel (refereegranskat)abstract
- Background The relationship between biomechanical properties and biological activities in aortic aneurysms was investigated with finite element simulations and F-18-fluoro-deoxy-glucose (F-18-FDG) positron emission tomography. Methods and Results The study included 53 patients (45 men) with aortic aneurysms, 47 infrarenal (abdominal aortic) and 6 thoracic (thoracic aortic), who had 1 F-18-FDG positron emission tomography/computed tomography. During a 30-month period, more clinical events occurred in patients with increased F-18-FDG uptake on their last examination than in those without (5 of 18 [28%] versus 2 of 35 [6%]; P=0.03). Wall stress and stress/strength index computed by finite element simulations and F-18-FDG uptake were evaluated in a total of 68 examinations. Twenty-five (38%) examinations demonstrated 1 aneurysm wall area of increased F-18-FDG uptake. The mean number of these areas per examination was 1.6 (18 of 11) in thoracic aortic aneurysms versus 0.25 (14 of 57) in abdominal aortic aneurysms, whereas the mean number of increased uptake areas colocalizing with highest wall stress and stress/strength index areas was 0.55 (6 of 11) and 0.02 (1 of 57), respectively. Quantitatively, F-18-FDG positron emission tomographic uptake correlated positively with both wall stress and stress/strength index (P<0.05). F-18-FDG uptake was particularly high in subjects with personal history of angina pectoris and familial aneurysm. Conclusions Increased F-18-FDG positron emission tomographic uptake in aortic aneurysms is strongly related to aneurysm location, wall stress as derived by finite element simulations, and patient risk factors such as acquired and inherited susceptibilities.
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