Routine extended follow-up surveillance of iliac vein stents for iliocaval venous obstruction may not be warranted

Objective: The purpose of this study was to evaluate outcomes of iliac vein stents placed for iliocaval venous obstruction (ICVO) and to determine if routine follow-up surveillance is warranted on the basis of timing of stent failure. Methods: All patients who underwent iliac vein stenting from 2003 to 2015 were identified from a prospectively maintained registry. Demographics of the patients, venous risk factors, prior venous interventions, indications, imaging, anatomic location of the ICVO, operative findings, procedural success, complications, and clinical follow-up were recorded. Clinical and ultrasound surveillance was performed at first postoperative follow-up and at routine subsequent intervals. Continuous data were analyzed with Student t-tests or Mann-Whitney U test, and frequency data were analyzed with x(2) analysis or Fisher exact test. Primary patency was analyzed using Kaplan-Meier survival analysis. Results: Seventy-four limbs in 70 patients who underwent iliac vein stenting for ICVO were identified: 36 limbs (48.6%) were stented for nonthrombotic venous compression (stent-VC), and 38 limbs (51.4%) were stented for venous thrombosis (stent-VT). Twenty-seven limbs (71.1%) of the stent-VT group were treated for acute venous thrombosis requiring lysis followed by stenting for underlying venous lesions. The median number of follow-up visits for the stent-VC and stent-VT groups was two (interquartile range [IQR], 1-4) and two (IQR, 1-3), whereas the mean length of follow-up was 19.6 29.5 months and 19.8 +/- 26.5 months (P = .972), respectively. During the first 6 months, one limb (2.8% [n = 36]) in the stent-VC group occluded, whereas 13.2% (5/38) of the limbs in the stent-VT group occluded. In the stent-VT group, 57% of limbs (4 of 7) with acute venous thrombosis requiring thrombolytic therapy had limb occlusion at >6 months (median, 18.1 months: IQR,16.6-30.1). Overall patency rates for the stent-VC and stent-VT groups were 97.2% (1/36) and 73.7% (10/38) at 36 months (standard error, :5_10%; P = .001), respectively. Conclusions: Iliac vein stents placed for nonthrombotic iliac vein compression had statistically higher patency than those placed for venous thrombosis, with few stent failures, all occurring within 6 months. Iliac vein stents placed for venous thrombosis continued with stent failure after 6 months and may benefit from extended surveillance.