Timing of outpatient stenting is associated with stent size in nonthrombotic iliac vein lesions

Objective

Stent placement is commonly used to treat nonthrombotic iliac vein lesions (NIVLs). On the day of surgery, patients typically fast after midnight and may often present with volume deficits and various degrees of dehydration. This study aims to determine if the time of day stenting is performed predicts the size of the iliac vein stent used to treat NIVLs.

Methods

A retrospective study of patients who underwent outpatient stenting and first-time treatment for NIVLs at a single institution from January 2013 to March 2022 was performed. The exposure variable was the time of day the outpatient stenting was performed, serving as a proxy for fasting duration. Stent timing was dichotomized into an early cohort (procedures before 11 am) and a late cohort (procedures after 11 am). Small stent size was defined as 12 to 16 mm, and large stent size was defined as 18 to 22 mm. A multivariable logistic regression analysis evaluated the independent association between the timing of stenting and iliac vein stent size.

Results

Sixty-four patients met the inclusion criteria, with 53% (n = 34) in the late cohort. The median age of the study population was 53 years (interquartile range, 39-64 years). Patients were 75% female, 30% non-White, and 69% non-Hispanic. Although there were no significant differences in baseline characteristics or iliac vein measurements on intravascular ultrasound examination before stenting between the early and late cohorts, patients in the early cohort were significantly more likely to have a large stent size used compared with the late cohort (70% vs 44%; P = .037). On multivariable logistic regression, each additional hour later in the day that stenting was performed was associated with a 28% higher odds of using a smaller venous stent (P = .036). Older age also independently predicted the implantation of a smaller stent (odds ratio, 0.95; 95% confidence interval, 0.91-0.99; P = .022).

Conclusions

Outpatient stenting performed later in the day was associated with a smaller stent size in patients treated for NIVLs. A 9-hour delay in stent placement was associated with a 2-mm reduction in stent diameter (ie, one stent size smaller). Future studies should investigate the role of a preoperative hydration protocol in optimizing stent sizing for patients with iliac vein lesions.