Effects of catheter sizing on pressure gradient measurements in a model of vessel stenosis

Introduction Current clinical practice lacks reliable diagnostic tools for Chronic Mesenteric Ischemia (CMI), often relying on symptom relief post-recanalization for definitive diagnosis. Mesenteric artery pressure gradients (PG) during intervention offer insight into the hemodynamic significance of mesenteric artery stenosis (MAS) and potential compensatory collateral circulation. This study aims to compare the differences in PG measurements obtained with a macrocatheter, microcatheter, and pressure wire across varying degrees of stenosis, using an in-vitro model of the two most commonly stented mesenteric arteries: the celiac artery (CA) and superior mesenteric artery (SMA). Materials and Methods Using an in-vitro model, we simulated postprandial states in the superior mesenteric artery (SMA) and celiac artery (CA), measuring flow rates across 24 3D printed stenoses with a macrocatheter, microcatheter and pressure wire. Fractional Flow Reserve (FFR) quantified the effects of catheter sizing on pressure gradient measurements. Results Reliability of FFR measurements using a macrocatheter was lower in stenosis exceeding 75% as well as longer stenosis as it tends to overestimate hemodynamic significance of MAS and underestimates collateral circulation compensation mechanisms, whereas the macrocatheter consistently shows a larger variability compared to the microcatheter and pressure wire in each stenosis category (5 mm, 10 mm, 15 mm, and 20 mm). Conclusions For stenoses ≤ 75%, microcatheter, macrocatheter, and pressure wire are comparable in assessing FFR. However, caution is warranted for stenoses > 75% or longer stenoses, as macrocatheter tends to overestimate FFR. Considering applicability and costs, microcatheter is recommended for clinical use.