Quickshot: Fasting Duration Prior to Venography Is Associated with Stent Size in Patients with Iliac Vein Compression
Monday, March 4, 2024
2:37 PM – 2:43 PM EST
Location: Tampa Bay Ballroom Salons 1-4
Objective: Patients with nonthrombotic iliac vein compression (NIVL) are treated with stenting and typically fast after midnight on the day of surgery. Therefore, they present with various degrees of dehydration depending on the duration of fasting and the timing of the procedure. The purpose of this study is to determine if the time of day of a venogram correlates with the size of the iliac vein stent used for NIVL. Our hypothesis is that patients undergoing iliac vein stenting later in the day receive smaller stents because of dehydration.
Methods: A retrospective study of an institutional database of outpatient venography and first-time treatment for NIVL was performed. Since patients were “nil per os” starting at midnight and up until their procedure took place, the time of day of the venogram served as a proxy for hydration status, and this duration of fasting was calculated in minutes after midnight. The patients were divided into two groups: procedures before 11AM (early group) and procedures after 11AM (late group). A multivariable linear regression evaluated the independent association of the duration of fasting and iliac vein stent size after adjusting for age, sex, race, ethnicity, body mass index, and patient positioning.
Results: There were 64 patients with chronic venous insufficiency who underwent outpatient iliac vein stenting for NIVL with 53% (n=34) in the late group. The mean age of the study population was 52 years, with 75.0% female and a majority white (70.3%) with no significant difference in baseline characteristics between the two groups (Table). The mean duration of fasting for the early group was significantly shorter than the late group [525 min (8hr 45 min) vs 813 min (13hr 33min), p< 0.01]. In the early group compared to the late group, there was a trend towards larger CIV area, and no difference in the degree of stenosis. There was also a trend towards larger median stent size in the early group (18mm vs. 16mm, p=0.06) compared to the late group with approximately one stent size difference (2mm). On multivariable linear regression, the duration of fasting was correlated with the size of the iliac vein stent (p=0.036). A 9-hour fasting duration was correlated with a 2mm decrease in stent size.
Conclusions: Fasting duration prior to venography is associated with stent size in patients treated for NIVL. Future studies should investigate the role of a preoperative intravascular hydration protocol on appropriate stent sizing for patients with iliac vein compression.
