Impact of Presence of Inferior Vena Cava Filter on Iliocaval Stent Outcomes

Abstract

The impact of presence of an IVC filter in patients undergoing stenting for symptomatic femoroiliocaval obstruction has not been explored in detail. This study attempts to fill this gap by evaluating clinical and stent-related outcomes in such patients. The incidence of deep vein thrombosis (DVT) in this setting is also analyzed. A retrospective review of contemporaneously entered EMR data on initial iliocaval stents placed in patients with an indwelling IVC filter (or placed after stenting) over a 15-year period from 2000 to 2015 was performed. A separate matched cohort that underwent initial stenting during the time frame, but which did not have an IVC filter, was utilized as the control group. Clinical outcomes were evaluated through use of the venous clinical severity score (VCSS) and visual analog scale (VAS) pain scores. Incidence of deep venous thrombosis after stenting was also reviewed in both groups. The Kaplan-Meier analysis was used to assess stent patency after intervention while t-tests were used to examine preintervention and postintervention outcomes within and in-between groups. A total of 50 limbs (40 patients) underwent placement of a femoroiliocaval stent in the setting of a preexisting (49) or post-stent (1) IVC filter [filter group]. The control group had 156 limbs (155 patients). There was no difference in VCSS, VAS pain score, or grade of swelling at baseline between the 2 groups. Over the median follow-up duration (43months-filter group; 40months-control group), VCSS went from 6 to 4 at 12months (P=0.0001) in the filter group and from 6 to 4 in the control group (P<0.0001). VAS pain scores went from 7 to 0 at 12months (P<0.0001) in the filter group and from 5 to 0 in the control group (P < 0.0001). There was no significant difference in the VCSS scores or VAS pain score between the 2 groups at 12months (P>0.05). Overall, there was a statistically significant increase in the incidence of DVT in the filter group (10%) compared to the control group (3%) [P=0.03%]. Primary, primary assisted, and secondary patencies in the filter/control groups at 48 months were 64%/65% (P=0.6), 100%/97% (P=0.5), and 100%/75% (P=0.4), respectively. Reintervention from in-stent restenosis was noted in 16% of patients in the filter group compared to 4% in the control group (P=0.006). Patients with an IVC filter in the setting of a femoroiliocaval stent tend to have an increased rate of deep venous thrombosis on the stented side. In addition, an increased rate of reintervention secondary to in-stent restenosis was also noted. In light of this, every attempt should be made to remove the IVC filter as soon as the need for the filter no longer exists.