title: The incidence of contralateral iliac venous thrombosis after stenting across the iliocaval confluence in patients with acute or chronic venous outflow obstruction.
abstract: OBJECTIVE
  Percutaneous transluminal angioplasty with stenting of the iliac veins is the method of choice to treat patients with symptomatic lower extremity venous outflow obstruction. The optimal method of performing this technique remains to be solved, however. One question in particular is that when braided stainless steel stents (Wallstents; Boston Scientific, Natick, Mass) are used, should these venous stents extend into the vena cava or should they stop short of this for fear of causing thrombosis of the patient's normal contralateral iliofemoral vein? It has been our practice to extend our venous stents significantly into the vena cava to coapt with the inferior vena cava (IVC) wall in the majority of patients with disease of the common iliac vein at the iliocaval junction. The aim of this study was to assess whether this placement led to thrombosis of a normal contralateral common iliac vein.
  
  
  METHODS
  We retrospectively reviewed prospectively collected data from 2008 to 2012 in patients with symptomatic acute or chronic iliocaval venous obstruction who underwent percutaneous angioplasty and stenting at our institution. Data were collected by use of the American Venous Forum venous stent database variables. Stent patency rates and the incidence of contralateral iliac vein thrombosis were analyzed.
  
  
  RESULTS
  In 65 patients (median age, 48 years; range, 15-80 years), 200 iliocaval stents were placed. Of these patients, 41 received ipsilateral stents that extended into the IVC and completely across the contralateral common iliac vein orifice; 39 (95%) of these had venous outflow obstruction as a result of thrombotic disease. In 22 patients (54%), post-thrombotic disease involved the IVC. All patients had stents that extended into the IVC, crossing the normal contralateral iliac vein orifice completely. Most patients (97.5%) were maintained by full anticoagulation with warfarin or low-molecular-weight heparin. Four patients (9.7%) suffered new thrombosis of the nonstented contralateral iliofemoral vein; two patients had initial involvement of the IVC, and three were totally noncompliant with their postoperative anticoagulation. Thus, 2.4% of compliant patients had new contralateral thrombosis after stenting across a normal contralateral common iliac vein and into the vena caval wall. In this select patient population, univariate analysis of patient compliance with the postoperative anticoagulation strategy showed a strong correlation with postoperative contralateral iliofemoral venous thrombosis (P = .0004).
  
  
  CONCLUSIONS
  From these data, it appears that stenting across the iliocaval confluence can be done safely in the majority of patients maintained with therapeutic anticoagulation. In post-thrombotic patients, however, stenting across the iliocaval confluence can result in a small number of new contralateral thromboses, more often if the patients are noncompliant with anticoagulation after stenting. Current stent technology limits the ability of practitioners to treat common femoral venous obstruction precisely. Future stent development is likely to eliminate the need to cross the iliocaval confluence and risk contralateral venous thromboses.
authors.affiliation: Division of Vascular Surgery, University of Rochester School of Medicine and Dentistry, Rochester, NY.
authors.forename: Xzabia A
authors.initials: XA
authors.lastname: Caliste
authors.affiliation: Division of Vascular Surgery, University of Rochester School of Medicine and Dentistry, Rochester, NY.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Clark
authors.affiliation: Division of Vascular Surgery, University of Rochester School of Medicine and Dentistry, Rochester, NY.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Doyle
authors.affiliation: Division of Vascular Surgery, University of Rochester School of Medicine and Dentistry, Rochester, NY.
authors.forename: John P
authors.initials: JP
authors.lastname: Cullen
authors.affiliation: Division of Vascular Surgery, Cardiovascular Care Center, Southcoast Health System, Fall River/New Bedford, Mass. Electronic address: gillespied@southcoast.org.
authors.forename: David L
authors.initials: DL
authors.lastname: Gillespie