venous valve

ve·nous valve

a fold of the lining layer of a vein to prevent a reflux of blood.
Synonym(s): valvula venosa (2) [TA]
Farlex Partner Medical Dictionary © Farlex 2012
References in periodicals archive ?
Treatment modalities include use of anticoagulant, catheter directed thrombolysis, stent placement, placement of filters, surgical approaches including vein patch angioplasty with excision of intraluminal bands, division of the right common iliac artery and relocation behind the left common iliac vein or inferior vena cava and saphenous vein graft bypass to the inferior vena cava or ipsilateral common femoral vein.2 Reestablishment of vessel patency by removing the thrombus, relieving the acute symptoms in order to prevent recurrent thrombosis and pulmonary embolism and to reserve venous valve function, thus preventing post-thrombotic syndrome is the main purpose of treatment for postpartum DVT.
The onset of superficial CVI occurs due to a vertical venous reflux caused by the ostial venous valve at the level of the saphenous-femoral junction, or due to a horizontal reflux triggered by the degradation of the ostial valves of the perforator veins that leads to venous reflux from the profound to the superficial venous network.
In a review of 9146 patients undergoing anterior cruciate ligament reconstruction, Bokshan suggested that increasing age over 30 years and hypertension were associated with an increased risk of DVT.13 Alanazi's study also drew the same conclusion.14 Elderly population are usually associated with vascular sclerosis, high blood viscosity and poor venous valve function, this may be the reason for a high rate of DVT.8 In terms of hypertension, its association with the development of DVT is a controversial issue.
In practice, alarm-free dialysis initiation indicates an optimal needle position with the jet stream from the venous needle directed to the centre of the vessel lumen flowing free of obstacles (i.e., a venous valve) or barriers (i.e., needle against the vessel wall).
Furthermore, the distance between a PIVC and a more central branch is likely to contain a venous valve preventing retrograde blood flow.
Experimental studies have revealed that retrograde air emboli can occur in venous vasculature in the setting of certain circumstances, such as putting the patient in a supine position or at least at an angle of 45 [degrees]C to the horizontal plane, venous valve insufficiency, and increased venous pressure in the right cavities of the heart (7,8).
Sugano et al., "Preservation of venous valve function after catheter-directed and systemic thrombolysis for deep venous thrombosis," European Journal of Vascular and Endovascular Surgery, vol.
Tsitlik et al., "Determinants and clinical significance of jugular venous valve competence," Circulation, vol.
Tricuspid regurgitation and high central venous pressure, possibly coupled with venous valve incompetence, caused this patient's pseudoaneurysm to manifest as it became engorged with blood.
(d) Digital substraction angiography (DSA): a mechanical obstruction in this area with a tortuous right common iliac vein precluded advancement of the MitraClip system (the depicted arrow may indicate a venous valve).
Older age is often associated with vascular sclerosis, poor venous valve function, and high blood viscosity.
Venous ulcers arise from venous valve incompetence and calf muscle pump insufficiency which leads to stasis and venous hypertension.11 This results in microcirculatory changes and localized tissue ischemia.