Computer Modeling of Controlled Microsphere Release and Targeting in a Representative Hepatic Artery System

Abstract

Combating liver tumors via yttrium-90 ((90)Y) radioembolization is a viable treatment option of nonresectable liver tumors. Employing clinical (90)Y microparticles (i.e., SIR-Spheres and TheraSpheres) in a computational model of a representative hepatic artery system, laminar transient 3D particle-hemodynamics were simulated. Specifically, optimal particle release positions in the right hepatic (parent) artery as well as the best temporal release window were determined for the microspheres to exit specific outlet daughter vessels, potentially connected to liver tumors. The results illustrate the influence of a curved geometry on the velocity field and the particle trajectory dependence on the spatial and temporal particle injection conditions. The differing physical particle characteristics of the SIR-Spheres and the TheraSpheres had a subtle impact on particle trajectories in the decelerating portion of the arterial pulse, i.e., when the inertial forces on the particles are weaker. Conversely, particle characteristics and inelastic wall collisions had little effect on particles released during the accelerating phase of the arterial pulse, i.e., both types of microspheres followed organized paths to predetermined outlets. Such results begin paving the way towards directing 100% of the released microspheres to specific daughter vessels (e.g., those connected to tumors) under transient flow conditions in realistic geometries via a novel drug-particle targeting methodology.

99mTc-Macroaggregated Albumin Poorly Predicts the Intrahepatic Distribution of 90Y Resin Microspheres in Hepatic Radioembolization

“…7). These differences are known to cause substantial differences in preferential flow (23)(24)(25). Innovative catheter designs with spacers to keep the catheter tip centered in the arterial lumen during injection may lead to more comparable injection positions and subsequent improved agreement between 99m Tc-MAA and 90 Y activity distribution (26).…”

A study concerning morphometry of abdominal aorta branches and abdominal viscera: relations and correlation

“…Some authors [84] believe that variations existence is related to smaller diameter and thus less satisfactory results and more complications while others [36] support the opposite. Detailed common hepatic artery morphometry knowledge is necessary for generation of flow models, critical for chemoembolisation procedures and microspheres design [5]. Common hepatic artery diameter increases in some diseases like cirrhosis and alcoholic hepatitis [34].…”

“…Stent grafts design and placement for endovascular repair of AA and branches aneurysms [38,40], chemoembolisation for haemorrhage or chemotherapy [5], visceral aneurysm diagnosis and treatment [8] and transplantation [36,87] are based on precise calculation of AA branches' diameters. Diagnosis, staging and treatment of many relative common diseases including chronic mesenteric ischaemia or other occlusive diseases of AA branches [25] and chronic renal insufficiency [3] utilise such measurements.…”

Nanodrug Delivery for Tumor Treatment

“…While tissue penetration can be overcome by implanting ferromagnetic materials near the target site [25], this adds complexity and invasiveness to the procedure. As a result, an alternative method of "optimal drug targeting" was proposed by Kleinstreuer [26] and his research group [27][28][29][30][31][32].…”