003 - Effects of Changes in Volume Status in Patients with May-Thurners
khanjan Nagarsheth, MD – Associate Professor of Surgery, Vascular Surgery, University of Maryland Medical Center
Purpose: Venous compression disorders rely on invasive imaging via venogram or intravascular ultrasound (IVUS) for both diagnosis and surgical planning. When diagnosing chronic venous compression that involves the pelvic vessels or the lower extremities, common practice involves utilizing the 200-150-125 rule as a standardized guide for normal diameters of the common iliac veins, external iliac veins, and the common femoral veins as variation between patients is usually ≤10% however these values, when used in a patient population that is known to have poor oral intake, do not take into consideration the overall volume status of the patient. This study seeks to determine if there are changes in the overall diameter of the left common iliac vein (LCIV), the left external iliac vein (LEIV), and the left common femoral vein (LCFV) when a patient is pre-hydrated, whether a patient’s volume status should be considered when performing invasive diagnostic imaging when evaluating for a venous compression disorder, and elucidate a possible additional component in the formation of deep vein thromboses (DVT) in patients being evaluated for May-Thurners syndrome.
Material and Methods: Between August 2021 and April 2022, a total of 26 venograms with IVUS were performed on patients with an average body mass index of 21 with the most reported symptom being abdominal pain. These patients received hydration with a 500 mL normal saline bolus and measurements of the LCIV, LEIV, and LCFV were obtained both before and after the bolus was given. The changes in the diameter of these veins in addition to the stenotic segment pre and post-hydration were calculated as a percent change with statistical analysis performed utilizing a paired t-test.
Results: For the LCIV, LEIV, and the LCFV all of the patients that received a 500cc fluid bolus had a statistically significant increase in the diameter of the veins measured with 40% of patients having a worsening of the stenotic segment within the LCIV.
Conclusions: This study shows that pre-hydration prior to venogram and IVUS simulating euvolemia or hypervolemia causes a change in the venous intraluminal diameter resulting in underestimation of the degree of stenosis when evaluating patients for venous compression disorders. This shows that a patients overall fluid status should be considered prior performing these studies as well as provides additional reasoning for the development of DVTs in this patient population.