Numerical Simulation of Blood Flows in Patient-specific Abdominal Aorta with Primary Organs.

The abdominal aorta is the largest artery in the abdominal cavity that supplies blood flows to vital organs through the complex visceral arterial branches, including the celiac trunk (the liver, stomach, spleen, etc.), the renal arteries (the kidneys) and the superior and inferior mesenteric arteries (the small and large intestine, pancreas, etc.). An accurate simulation of blood flows in this network of arteries is important for the understanding of the hemodynamics in various organs of healthy and diseased patients, but the computational cost is very high. As a result, most researchers choose to focus on a portion of the artery or use a low-dimensional approximation of the artery. In the present work, we introduce a parallel algorithm for the modeling of pulsatile flows in the abdominal aorta with branches to the primary organs, and an organ-based two-level method for calculating the resistances for the outflow boundary conditions. With this highly parallel approach, the simulation of the blood flow for a cardiac cycle of the anatomically detailed aorta can be obtained within a few hours, and the blood distribution to organs including liver, spleen and kidneys are also computed with certain accuracy. Moreover, we discuss the significant hemodynamic differences resulted from the influence of the peripheral branches. In addition, we examine the accuracy of the results with respect to the mesh size and time-step size and show the high parallel scalability of the proposed algorithm with up to 3000 processor cores.

Analysis of orthopedic surgery of patients with metastatic bone tumors and pathological fractures.

Objective This study was performed to determine the most common causes, locations, and treatments of metastasizing primary tumors through evaluation of patients with metastatic bone tumors who were admitted to our clinic. Methods In total, 96 patients with metastatic bone tumors who were admitted to our clinic from 2000 to 2016 were included in the study. Results The breast (30 patients, 31.3%) and lung (18 patients, 18.8%) were the most commonly metastasized primary organs. The femur was the most commonly metastasized bone. Conclusions Bone tumors in patients of advanced age are, unless otherwise proven, considered to be metastatic, and the development of specific diagnostic and treatment algorithms is needed. Clinicians should attempt to improve the general condition of patients with tumors exhibiting bone metastasis to increase the patients' quality of life by providing early mobilization. Thus, appropriate patient selection and proper internal fixation are essential.

Clinical Features of Systemic Metastatic Retinal Lymphoma in Japanese Patients.

PURPOSE: Systemic metastatic retinal lymphoma (SMRL) originates in systemic organs. It has been reported to exhibit clinical features similar to those of primary vitreoretinal lymphoma (PVRL). We report six cases of SMRL in a single-center survey in Japan. METHODS: The clinical and pathologic features in SMRL at the Kyushu University Hospital were retrospectively studied. RESULTS: The mean patient age at the onset of ocular involvement was 75.3 years. Four patients had brain involvement. The primary sites were: breast (2); chest (1); testis (1); intestinal tract (1); and nasal sinus (1). In all patients, the cytology of vitreous samples indicated diffuse large B-cell lymphoma (DLBCL). CONCLUSIONS: DLBCL is the most common subtype in our study. The prevalence of CNS involvement in patients with SMRL is similar to that with PVRL. The testis and breast may be common sites of origin for SMRL.