Criteria for defining significant central vein stenosis with duplex ultrasound

Abstract

DU is a sensitive method to identify a clinically significant vein stenosis. A peak vein velocity ratio of >2.5 across the stenosis is the best criterion to use for the presence of a pressure gradient of =3 mm Hg. DU can be used to select patients for intervention and also to monitor the success of the treatment during follow-up.

Blood flow velocity in the popliteal vein using transverse oscillation ultrasound

“…All these can assess the grade of flow restrictions based on anatomical criteria i.e. the maximal degree of narrowing 6 . CTV, MRV and phlebography can all define vein morphology and flow characteristics when restricted flow is suspected especially in the pelvic or abdominal veins [7][8][9] .…”

Massive arm edema following arteriovenous dialysis shunt creation in a patient with ipsilateral permanent pacemaker

“…Sonographic criteria for central vein stenosis have been developed at our center by comparing it with pressure difference across stenosis, biplanar venography, and intravascular sonography. 8 Fibrous tissue is also easily recognized with sonography, because its acoustic impedance is very high (ie, very stiff and dense). The old thrombus appears the same way, because when it is not recanalized it is transformed into fibrous tissue.…”

Diagnosis and Treatment of Lower Extremity Deep Vein Thrombosis: Korean Practice Guidelines

“…The diagnostic accuracy of duplex US may be improved by performing direct duplex US examination of the iliocaval veins; however, reliable and reproducible imaging is limited by body habitus, intestinal gas, and operator variability [103]. For improved diagnostic accuracy, if additional information on the iliac vein is required, patients with suspected chronic thrombotic venous obstruction should undergo additional imaging studies by conventional venography, CT venography or MR venography [104][105][106].…”

“…In the PROLONG study, patients with an abnormal D-dimer level 1 month after discontinuation of anticoagulant for treatment of unprovoked VTE were randomized to resume warfarin or not. When the primary end-points of recurrent VTE and major bleeding were assessed, there were three events among the 103 [133,134]. Poor-quality INR control, as assessed by the percentage of time with INR <1.5, is associated with a long-term higher risk of recurrent VTE after eventual anticoagulant cessation (RR, 2.7; 95% CI, 1.39-5.25; P=0.003) [135].…”