Temporal analysis of arch artery diameter and flow rate in patients undergoing aortic arch endograft procedures

Abstract

Objective:To investigate the diameter and flow rate of aortic arch arteries, their post-operative changes, and relationship in patients undergoing thoracic endovascular repair (TEVAR). Approach:Patient-specific diameters and flow rates were collected in common carotid (CCA), subclavian (SA), and vertebral (VA) arteries using duplex ultrasound pre-operatively and up to post-operative 6 months. Main results:For either diameter or flow rate of CCA, SA, and VA, there was no significant difference between the left and right sides for the 12 patients (age 64 ± 12 years, mean ± SD). The diameters of CCA, SA, and VA did not change over time and the average diameters of all measures were 7.4 ± 1.0, 7.3 ± 1.0, and 3.9 ± 1.9 mm, respectively. The CCA and VA flow rates did not change over time and averaged 494 ± 142 and 100 ± 56 ml min−1, respectively, while the SA flow rates were 147 ± 80, 230 ± 104, 136 ± 73, and 116 ± 55 ml min−1 at pre-operative, post-operative 1 week, 1 months, 6 months, with a decrease from 1 week to 6 months (P = .017). The total flow rate of all branches decreased at 6 months compared to 1 week (P = .020). The CCA, SA, and VA best diameter-flow rate relationships showed power values of 1.6 (R2 = 0.51), 1.8 (R2 = 0.20), and 2.4 (R2 = 0.60), respectively. Excluding the SA, a strong quadratic diameter-flow rate relationship was observed for the CCA and VA combined (Q = 8.5*D2, R2 = 0.87). Significance:There is a strong quadratic relationship between diameters and flow rates for the CCA and VA, but not SA. Our study provides reference diameter and flow rate boundary condition data of aortic arch arteries for computational modeling of patients undergoing TEVAR procedures.

Non-invasive estimation of the parameters of a three-element windkessel model of aortic arch arteries in patients undergoing thoracic endovascular aortic repair

“…Different power laws have described the relationship between flow rate and diameter at various arterial levels (Murray, 1926;Cheng et al, 2007;Cebral et al, 2008;Revellin et al, 2009;Chnafa et al, 2017). We investigated the flow rate and diameter relationships of the arch branch arteries in the TEVAR patients using ultrasoundmeasured flow rates and CTA-measured lumen diameters (Tricarico et al, 2020a). The power values of the best fit flow rate-diameter relationships are between 1.6 and 2.4.…”

“…Mean flow rate can be measured by Doppler ultrasound if available or estimated from the previously published flow rate-diameter relationships based on the diameter extracted from CTA images, such as those reported by us (Tricarico et al, 2020a). CTA is routinely performed for diagnosis and treatment planning of aortic pathologies and is often used in clinical research to extract three dimensional arterial models.…”

“…Arterial diameters and flow rates were extracted from ultrasound images. Details on the methodology of flow rate calculation have been described in our previous work (Tricarico et al, 2020a).…”

Medical Image-Based Computational Fluid Dynamics and Fluid-Structure Interaction Analysis in Vascular Diseases

“…Using typical or population-averaged flow rates and waveforms is common, but still not ideal because of the heterogeneity among patients. Alternatively, since lumen area or diameter data are more readily available from non-invasive clinical images, the inlet flow rate and flow split through branches can be estimated using lumen area or diameter data and various scaling laws, such as Murray’s law based on minimum energy theory ( Murray, 1926 ), or developed from measured data ( Cebral et al, 2008 ; van der Giessen et al, 2011 ; Tricarico et al, 2020 ). In CFD simulations assuming a rigid wall, the velocity boundary condition at the wall is generally set as no-slip or zero-velocity.…”