During the 2024 American Venous Forum (AVF) annual meeting in Tampa, Florida (March 3–6), Kurt S. Schultz, MD, a general surgery resident at the Yale University School of Medicine in New Haven, Connecticut, presented data from a study exploring how fasting duration prior to venography is associated with stent sizing in patients with iliac vein compression, finding that a longer fasting duration was associated with a smaller iliac vein stent size.
He stated that, while iliac vein stenting is a viable treatment option, “inappropriate sizing of venous stents can have catastrophic complications, and there’s been an increased rise in reports of stent migration to the heart and lungs. Iliac vein size, as we know, depends on several factors, like BMI [body mass index] and whether the patient is prone or supine.”
Schultz and colleagues divided patients into two groups— those who received their procedures before 11 a.m. (early group) and those who received their procedures after 11 a.m. (late group).
The number of patients in the study was 64, with 30 being in the early group and 34 in the late group. Of the 64 patients, the mean age was 52 years old and 48 of the 64 were female.
Since these patients are typically fasting starting at midnight the day of their surgeries, “patients who are having elective procedures later in the day are likely to be more dehydrated,” Schultz told the audience.
“So, our hypothesis was patients undergoing iliac vein stenting later in the day would have smaller stents placed compared to those who had stents placed earlier in the day.”
The clinical outcomes supported the hypothesis, with the left common iliac vein and external iliac vein being larger in terms of surface area in the early group when compared with the late group. However, Schultz explained, “this didn’t reach statistical significance.”
The study found that, while delayed start times were associated with a smaller stent size, patients who were prone were also more likely to have a smaller stent size. The difference in fasting times for the two groups was significant, with a mean of eight hours and 45 minutes for the early group and 13 hours and 33 minutes for the late group.
“In conclusion, based on our linear regression we found that a nine-hour fasting duration was associated with an approximately 2mm decrease in stent size,” Schultz stated. “So, the longer fasting duration was associated with smaller iliac vein stent size.”
During the question-and-answer portion of the presentation, Schultz was asked about whether there were any complications in patients due to the size of the stents. He explained that, while he and his team have these data, they have yet to analyze it.
When asked about whether the patients had chronic pain associated with the oversized stents, as there is a larger issue with chronic pain as compared to catastrophic complications such as a stent migration, Schultz responded by saying that his team has the data to look at those complications, adding, “I think that’s an appropriate next step.”
Schultz explained that the study group will now look to develop a pre-procedural hydration protocol.
