Use of Computed Tomography and Magnetic Resonance Angiograms Combined with a 3D Surgical Guide in an Elderly Cat with an Occipital Lobe Meningioma

SIMPLE SUMMARY: Meningioma treatments, including complete surgical resection, debulking, radiation therapy, and palliative care in dogs and cats have recently been improved. Although complete resection of meningiomas is known to be the most effective treatment, there are still challenges in performing safe surgeries due to the presence of numerous vessels surrounding the tumor and brain parenchyma. Many efforts have been made in the field of human medicine to achieve safety, such as preoperative planning using 3D simulation and contrast angiography. Surgical navigation systems have been studied for application, but recently, three-dimensional techniques have helped surgeons perioperatively. This study enhanced the vessels around the meningiomas in the skull and attempted to identify them using 3D computed tomography and magnetic resonance imaging angiography rather than conventional angiography. An 11-year-old castrated male cat was referred to our hospital with a meningioma located in the occipital lobe. The cat showed progressive tetraparesis. Throughout the long-term follow-up, following the complete removal of the meningioma, the cat showed favorable clinical outcomes and no neurological abnormalities. ABSTRACT: We present a case of occipital lobe meningioma resection in an elderly cat. The surgery was performed with the goal of avoiding major bleeding. An 11-year-old castrated indoor-only male Persian Chinchilla (5.5 kg) was presented with a month-long history of progressive tetraparesis for a left occipital lobe meningioma. Magnetic resonance imaging revealed a T2-weighted heterogeneously hyperintensity and a T1-weighted well-contrast enhancing extradural mass in the left occipital lobe of the brain. Cerebral angiographic data were obtained using magnetic resonance (MRA) and computed tomography angiography (CTA). Advanced angiograms and virtual reconstruction of images revealed that the tumor was surrounded by the caudal parasagittal meningeal vein. A left caudal rostrotentorial craniotomy and en bloc resection of the tumor were performed, and histopathology revealed a meningioma. Complete neurological recovery was achieved within 10 days after surgery. To the best of our knowledge, this is the first case report describing CTA and MRA findings and favorable clinical outcomes after surgical management of a brain meningioma without severe perioperative complications.