The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
Seshadri Raju - One of the best experts on this subject based on the ideXlab platform.
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hemodynamic and clinical impact of ultrasound derived venous reflux parameters
Journal of Vascular Surgery, 2004Co-Authors: Peter Neglen, John F Egger, Jake Olivier, Seshadri RajuAbstract:Abstract Purpose This study was undertaken to assess which ultrasound-derived parameter was superior for measuring venous reflux quantitatively and to evaluate the importance of popliteal Vein Valve reflux. Patients and methods A retrospective analysis was performed of 244 refluxive limbs in 182 patients who underwent ultrasound scanning, venous pressure measurement, air plethysmography, and clinical classification of severity according to the CEAP score. Reflux time (RT, s), peak reflux velocity (PRV, m/s), time of average rate of reflux (TAF, mL/min), absolute displaced volume retrogradely (ADV, mL) were compared to clinical class, ambulatory venous pressure (% drop), venous filling time (s), and venous filling index (mL/s) using nonparametric statistical tests. A P value of Results No meaningful significant correlation was found between RT and the clinical and hemodynamic results in groups A and B. The PRV and TAF correlated significantly with the hemodynamic parameters. The PRV and TAF and clinical severity trended towards correlation in group A ( P = .0554 and P = .0998, respectively), but was significantly correlated in group B. The poor hemodynamic condition in the subset of C-class 4-6 limbs in groups A and B was reflected in a greater PRV, TAF, and ADV in this subset as compared with the limbs in C-class 1-3. RT was not significantly different in the subsets of limbs, further suggesting that RT is not related to hemodynamic or clinical state of the limbs. No meaningful correlations were found in group C. Although the hemodynamic data were significantly poorer in the subset of limbs with C-class 4-6 than in C-class 1-3, the ultrasound-derived parameters were not significantly different. Conclusion The duration of Valve reflux time (or Valve closure time) cannot be used to quantify severity of reflux and is purely a qualitative measurement. The PRV and the rate of reflux appeared to better reflect the magnitude of venous incompetence. In the presence of axial reflux, it appeared logical and physiologically correct to sum up these reflux parameters for each venous segment crossing the knee. The popliteal Valve reflux (the "gatekeeper" function) was not in itself an important determinant of venous hemodynamics and clinical severity. Additional reflux in other venous segments must be taken into account.
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axillary Vein Valve transplantation in patients with advanced chronic venous insufficiency long term valvular competence and clinical success
Perspectives in Vascular Surgery and Endovascular Therapy, 1999Co-Authors: Seshadri RajuAbstract:Axillary Vein Valve transfer is a useful technique of Valve reconstruction. It is the mainstay for reconstructing postthrombotic Vein segments in which Valve structures have been destroyed beyond repair. The technique may appear deceptively simple, but in fact it requires meticulous execution to be successful. Clinical results using the technique are similar to those obtained with direct Valve repair techniques. The results of axillary Vein transfer in postthrombotic syndrome are similar to those obtained in "primary" reflux with actuarial recurrence-free survival of >60% at 6 years. Deterioration in function as demonstrated by duplex competence is the main cause of clinical recurrence. Most of these failures occurred during the first 3 years after surgery, with the survival curves remaining stable thereafter.
Sebastian F Ameriso - One of the best experts on this subject based on the ideXlab platform.
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internal jugular Vein Valve incompetence is highly prevalent in transient global amnesia
Stroke, 2010Co-Authors: Claudia Cejas, Lucia Fernandez Cisneros, Roberto Lagos, Carlos Zuk, Sebastian F AmerisoAbstract:Background and Purpose— Transient global amnesia (TGA) is the inability to retain new information and to recall past events during a period of minutes or hours. Its etiology is unclear, and flow disturbances in the mesial temporal lobes secondary to venous congestion have been proposed as a potential cause. Ultrasonographic evaluation of the internal jugular Vein (IJV) has demonstrated valvular insufficiency in TGA. The prevalence of valvular insufficiency in the IJV in patients with TGA was assessed. Subjects without TGA of similar sex, age, and vascular risk factor profiles served as controls. Methods— A group of 142 patients with a clinical diagnosis of TGA within 7 days of the clinical event and 40 controls were prospectively evaluated. Venous Doppler examination of both IJVs was performed at baseline and after a manometer-controlled Valsalva maneuver. Valvular insufficiency was diagnosed when there was reflux for >0.8 seconds during the Valsalva maneuver. Results— Valve insufficiency was found in at ...
Fabrizio Vernieri - One of the best experts on this subject based on the ideXlab platform.
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internal jugular Vein Valve incompetence in transient global amnesia more circumstantial evidence or the proof solving the mystery
Stroke, 2010Co-Authors: Claudia Altamura, Fabrizio VernieriAbstract:See related article, pages 67–71. Transient global amnesia (TGA) was generally believed to have a psychogenic, epileptic, or thromboembolic etiology until the frequent comorbidity with migraine and the common accompanying symptoms (headache and dizziness) pointed toward cortical spreading depression as a pathogenic suspect.1,2 More recently, based on evidence that Valsalva-like activities may represent the precipitating factors in most TGA patients, cerebral venous congestion leading to venous ischemia was hypothesized as a possible pathophysiologic mechanism.3 Corroborating this hypothesis, the prevalence of internal jugular Vein (IJV) Valve incompetence, as assessed by ultrasound, was found to be more prevalent in patients with TGA than in controls.4–8 In all of these studies, IJV Valve incompetence was detected in 97 of 131 patients (74%) and in 65 of 191 controls (34%). In this issue of Stroke, Cejas and coauthors9 confirmed these findings in a larger population, reporting IJV Valve insufficiency in 113 patients with TGA (79.5%) and in 10 controls (25%). Apparently, this could solve …
Filip Rega - One of the best experts on this subject based on the ideXlab platform.
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infective endocarditis in patients after percutaneous pulmonary Valve implantation with the stent mounted bovine jugular Vein Valve clinical experience and evaluation of the modified duke criteria
International Journal of Cardiology, 2021Co-Authors: D Bos, Daniel De Wolf, Bjorn Cools, Benedicte Eyskens, Jelena Hubrechts, Derize Boshoff, Jacoba Louw, Stefan Frerich, Bartosz Ditkowski, Filip RegaAbstract:Abstract Aims: Percutaneous pulmonary Valve implantation (PPVI) has proven good hemodynamic results. As infective endocarditis (IE) remains a potential complication with limited available clinical data, we reviewed our patient records to improve future strategies of IE prevention, diagnosis and treatment. Methods: Medical records of all patients diagnosed with Melody® Valve IE according to the modified Duke criteria were retrospectively analyzed in three Belgian tertiary centers. Results: 23 IE episodes in 22 out of 240 patients were identified (incidence 2.4% / patient year) with a clear male predominance (86%). Median age at IE was 17.9 years (range 8.2–45.9 years) and median time from PPVI to IE was 2.4 years (range 0.7–8 years). Streptococcal species caused 10 infections (43%), followed by Staphylococcus aureus (n = 5, 22%). In 13/23 IE episodes a possible entry-point was identified (57%). IE was classified as definite in 15 (65%) and as possible in 8 (35%) cases due to limitations of imaging. Echocardiography visualized vegetations in only 10 patients. PET-CT showed positive FDG signals in 5/7 patients (71%) and intracardiac echocardiography a vegetation in 1/1 patient (100%). Eleven cases (48%) had a hemodynamically relevant pulmonary stenosis at IE presentation. Nine early and 6 late percutaneous or surgical re-interventions were performed. No IE related deaths occurred. Conclusions: IE after Melody® Valve PPVI is associated with a relevant need of re-interventions. Communication to patients and physicians about risk factors is essential in prevention. The modified Duke criteria underperformed in diagnosing definite IE, but inclusion of new imaging modalities might improve diagnostic performance.
Jose M Valdueza - One of the best experts on this subject based on the ideXlab platform.
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internal jugular Vein Valve incompetence in copd and primary pulmonary hypertension
Journal of Clinical Ultrasound, 2008Co-Authors: Florian Doepp, Jose M Valdueza, Dieter Bahr, Matthias John, Soren Hoernig, Stephan J SchreiberAbstract:Purpose. Under physiologic conditions, intact internal jugular Vein Valves (IJVVs) efficiently prevent retrograde venous flow during intrathoracic pressure increase. Chronically elevated central venous pressure found in patients with chronic obstructive pulmonary disease (COPD) and primary pulmonary hypertension (PPH) might lead to IJVV incompetence (IJVVI). The aim of this study was to analyze the prevalence of IJVVI in patients with COPD and PPH using duplex sonography (DUS). Method. We included 30 COPD patients, 5 PPH patients, and 100 healthy controls in the study. IJVVI was diagnosed if retrograde jugular blood flow was seen on DUS during a Valsalva maneuver. Retrograde venous flow intensity was evaluated and graded according to extent and duration of reflux. Results. IJVVI was found in 18 (60%) COPD patients and in all 5 (100%) PPH patients, which was significantly different from the controls (27%; p < 0.005). The intensity of venous retrograde flow correlated with the pulmonary artery pressure. Conclusion. Compared with healthy controls, COPDand PPH patients demonstrated a significantlygreater prevalence of IJVVI, which seems to be caused by the elevated central venous pressure. These patients may be at higher risk to develop central nervous system diseases related to cerebral outflow obstruction. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.
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internal jugular Vein Valve incompetence and intracranial venous anatomy in transient global amnesia
Journal of Neurology Neurosurgery and Psychiatry, 2005Co-Authors: Stephan J Schreiber, Florian Doepp, Randolf Klingebiel, Jose M ValduezaAbstract:Background: Recently a causal relation between internal jugular Vein Valve incompetence (IJVVI) and transient global amnesia (TGA) has been suggested. IJVVI is postulated to provoke a transient mesiotemporal ischaemia by venous congestion. This mechanism requires a patent venous pathway from the affected IJV through the transverse sinus, confluens, straight sinus (SS), Vein of Galen into the basal Vein of Rosenthal and the internal cerebral Veins. Objective: To study IJVVI in TGA patients in relation to the intracranial venous anatomy. Methods: IJVVI was defined if a repeated Valsalva manoeuvre (VM) led to a retrograde jugular flow detected by extracranial duplex ultrasound. Non-contrast venous MR angiography (MRA) was performed to analyse intracranial drainage patterns of the SS in relation to the side of the IJVVI. SS drainage was differentiated into three groups: predominantly right, left, and bilateral drainage. Ultrasound studies were performed in 25 TGA patients and 85 age matched controls. Twenty patients underwent venous MRA. Results: Sixty eight per cent of patients and 33% of controls showed unilateral or bilateral IJVVI (p = 0.0025). In 36% of patients a TGA preceding VM was reported. Drainage pattern of SS and side of IJVVI corresponded in five of eight patients (63%) with VM and four of 12 patients without VM (33%, p = 0.0994). Conclusion: Our study confirms the significantly higher prevalence of IJVVI in TGA patients. However, no specific IJVVI related intracranial venous drainage patterns could be found to further support the hypothesis of a direct causal relation between IJVVI and TGA.
