Establishing a Quantitative Endpoint for Transarterial Embolization From Real-Time Pressure Measurements

Abstract

Transarterial embolization (TAE) is a standard-of-care treatment for tumors in which embolic particles are locally injected via a catheter to occlude blood flow and induce ischemia in the target tissue. Physicians currently rely on subjective visual cues from fluoroscopy in order to determine the procedural endpoint relative to the injection site. This contributes to highly variable treatment outcomes, including the accumulation of embolic particles in healthy tissue, called off-target embolization. To address this concern, we describe a novel, multi-lumen catheter that 1) measures real-time pressure upstream of the tumor site during TAE injection; and 2) associates that measurement with the volume of embolic particles injected. Using an in vitro silicon vascular model, we characterize the relationship between blood flow, intravascular pressure, and injection pressure. Furthermore, we identify a predictive pressure curve based on the volume of embolic particles injected. This approach has the potential to standardize and optimize TAE, reducing the likelihood of incomplete or off-target embolization, and improving patient outcomes.

Control of the injection velocity of embolic agents in embolization treatment

“…However, the practical implications of the time variability of heartbeat and blood pressure on the actual injection effect have not been explored theoretically nor applied in clinical practice. Gowda et al utilized an extracorporeal silicone vascular model to establish a correlation between the measured blood pressure values and the injected volume of embolic particles, as well as to explore the relationship among blood flow, intravascular pressure, and injection pressure [ 11 ]. However, their discussion was limited to the feasibility of blood pressure as an endpoint for embolization, and they did not extensively investigate the control of embolic agent injection velocity based on local arterial pressure.…”

“…If there was still tumor-staining, embolization was continued until the endpoint was reached (tumor staining disappeared) [ 10 ]. This causes not only radiation damage to doctors, but also this visual prompt is subjective and cannot accurately represent the physiological endpoint of the operation [ 11 ]. Therefore, considerable research is devoted to judging the embolic endpoint by more effective means, such as quantitative digital subtraction angiography (qDSA) technique [ 12 ].…”

Modular 3D-printed liver tumour phantom for modelling embolization procedures

“…Numerous phantoms have been designed for investigating embolic particle flow behaviour by mimicking the greater liver vessel architecture, [11][12][13][14][15][16] tumour microvasculature, 12,13,16 hepatic artery flow rates, [11][12][13][14][15][16] pressures, [12][13][14]16 resistances, [12][13][14][15] and flow pulsatility. [11][12][13] However, to our knowledge, none of these models were developed to mimic the radiographic appearance of liver and tumour vessels during angiography.…”

“…Vessel networks were generally designed along a planar surface where branching vessels fanned outwards. [11][12][13][14][15][16] Although it allowed more accurate quantification and visualization of embolic particle distribution, the phantoms took up large surface areas to represent vessel networks that are usually compact.…”