Assessing the Effects of Geniculate Artery Embolization in a Nonsurgical Animal Model of Osteoarthritis.

PURPOSE: To create a nonsurgical animal model of osteoarthritis (OA) to evaluate the effects of embolotherapy during geniculate artery embolization (GAE). MATERIALS AND METHODS: Fluoroscopy-guided injections of 700 mg of sodium monoiodoacetate were performed into the left stifle in 6 rams. Kinematic data were collected before and after induction. At 10 weeks after induction, Subjects 1 and 4-6 underwent magnetic resonance (MR) imaging with dynamic contrast enhancement (DCE) and Subjects 1, 3, and 4-6 underwent angiography with angiographic scoring to identify regions with greatest disease severity for superselective embolization (75-250-µm microspheres). Target vessel size was measured. At 24 weeks after angiography, DCE-MR imaging, angiography, and euthanasia were performed, and bilateral stifles were harvested. Medial/lateral tibial and femoral condylar, patellar, and synovial samples were cut, preserved, decalcified, and scored using the Osteoarthritis Research Society International criteria. The stifle and synovium Whole-Organ Magnetic Resonance Imaging Score and Multicenter Osteoarthritis Study score were determined. The volume transfer constant (Ktrans) and extracellular volume fraction (ve) were calculated from DCE-MR imaging along the lateral synovial regions of interest. RESULTS: The mean gross and microscopic pathological scores were elevated at 38 and 61, respectively. Mean synovitis score was elevated at 9.2. Mean pre-embolization and postembolization angiographic scores were 5 and 3.8, respectively. Mean superior, transverse, and inferior geniculate artery diameters were 3.1 mm ± 1.21, 2.0 mm ± 0.50, and 1.6 mm ± 0.41 mm, respectively. Mean pre-embolization and postembolization cartilage and synovitis scores were elevated at 35.13 and 73.3 and 5.5 and 9.2, respectively. The Ktrans/ve values of Subjects 4, 5, and 6 were elevated at 0.049/0.38, 0.074/0.53, and 0.065/0.51, respectively. Altered gait of the hind limb was observed in all subjects after induction, with reduced joint mobility. No skin necrosis or osteonecrosis was observed. CONCLUSIONS: A nonsurgical ovine animal knee OA model was created, which allowed the collection of angiographic, histopathological, MR imaging, and kinematic data to study the effects of GAE.

Suburothelial Hematomas Masquerading as Neoplasms in a Patient with Supra-Therapeutic INR.

Suburothelial hemorrhages (Antopol-Goldman lesions) are a rare but important condition. When unsuspected in a patient with a bleeding diathesis on anticoagulation therapy, computed tomography may lead to incorrect diagnoses of renal or transitional cell carcinoma resulting in inappropriate nephrectomy. We present a patient with supratherapeutic international normalized ratio and thigh hematoma who was found to have nonenhancing solid lesions of the bilateral renal pelves consistent with suburothelial hemorrhage. The patient's INR was controlled, and he was discharged with hematology follow-up 4 weeks later.