What predicts outcome after recanalization of chronic venous obstruction: hemodynamic factors, stent geometry, patient selection, anticoagulation or other factors?

In this review we evaluated the effect of different suggested factors associate with the outcome after recanalization of chronic venous obstruction (CVO). Hemodynamic factors:Based upon literature no clear suggestions can be made to identify the risk of stent occlusion in association with the hemodynamic effects. However it is evident that ensuring optimal in- and outflow of the stented tract is key in maintaining the patency. Patient selection:Noninvasive imaging modalities are used to divide patients in three subgroups based on the place and extension of post-thrombotic changes. Moreover it should be noted that AV fistula in selected patients can reduce the risk of thrombosis or re-occlusion. Geometry:Excessive oversizing of the stent and stent compression from outside are considered to be associated with stent occlusion. Additionally, overlapping rigid stents, unnatural angel between stents and in-stent kinking are other geometrical factors related to worse outcome after venous recanalization. Anticoagulation:Adequate peri-and postoperative anticoagulation has a crutial role in stent patency. There is no data regarding the duration of anticoagulation therapy and recommendations vary between 6 weeks to 6 months. Result:impaired inflow or outflow, presence of a hypercoagulability, total number of treated segments and use of stents designed for implantation in arterial system are associated with decreased stent patency.