Koichi Torihashi

Primary Intracranial Leiomyosarcoma with Intratumoral Hemorrhage: Case Report and Review of Literature

BACKGROUND Primary intracranial leiomyosarcoma is a very rare occurrence, and primary leiomyosarcoma with intratumoral hemorrhage has not been described previously. We present a case of a rapidly enlarging primary intracranial leiomyosarcoma with intratumoral hemorrhage. CASE DESCRIPTION A 41-year-old female presented with right hemiparesis and gait disturbance. She had a brain tumor on the frontal lobe that was growing rapidly. An intratumoral hemorrhage had occurred suddenly. We removed the tumor after hemorrhage. After the operation, postoperative chemotherapy and radiotherapy were not performed, but the tumor did not recur. CONCLUSIONS To the best our knowledge, this is the first report of primary intracranial leiomyosarcoma with intratumoral hemorrhage.

High-Flow Bypass with Internal Carotid Artery to Middle Cerebral Artery Bypass Using Radial Artery Graft Through the Supramandibular-Subzygomatic Route for Giant Internal Carotid Aneurysm: Technical Case Report

BACKGROUND A unique case of an internal carotid artery (ICA) giant aneurysm treated by high-flow bypass is presented. This patient had some anatomic variations in the neck region that posed problems for the high-flow bypass, and a new approach to address them is presented. CASE DESCRIPTION A 55-year woman presented with diplopia, abducens nerve palsy, severe headache, and disordered consciousness. She had a giant ICA aneurysm (diameter, 32 mm). Although high-flow bypass was considered, this patient had 3 anatomic issues that posed problems: an elongated styloid process, a high carotid bifurcation, and a meandering external carotid artery. Thus, some changes had to be introduced to proceed with the high-flow bypass. A tunnel radial artery (RA) graft was made between the supramandibular and subzygomatic areas, and an ICA-RA-M2 anastomosis was performed. The patients preoperative symptoms improved gradually after surgery. Magnetic resonance imaging and computed tomography showed good patency of the RA graft and no ischemic change. She was discharged without neurological deficits. CONCLUSIONS This case provided 2 new methods for high-flow bypass: RA graft route and the anastomosis of the ICA in carotid bifurcation. To our knowledge, this is the first case report of a high-flow bypass with a tunnel created for the RA graft (supramandibular-subzygomatic route) and an ICA-RA-M2 anastomosis.

The Method for Placement of an Intraoperative Continuous Facial Nerve Stimulating Electrode in Acoustic Neuroma Surgery: Technical Note

Preservation of facial nerve (FN) function is the most important goal in acoustic neuroma (AN) surgery. We have been using intraoperative continuous facial nerve monitoring (ICFNm) of evoked electromyography during AN surgery. ICFNm is very useful, and we can identify the real-time functions of the FN. Some surgeons have experienced difficulty with placing the ICFN stimulating electrode (SE). We therefore show how to place the ICFN SE. We mostly perform AN surgery with a retrosigmoid approach (RSA). A craniotomy with four burr holes is performed. We dissect the arachnoid membrane along the accessory nerve from the cisterna magna to the glossopharyngeal nerve. When we are able to identify the root exit zone (REZ) of the FN near the brainstem, we place the ICFN SE on it. However, when a large tumor covers the REZ, we have to debulk the tumor to create a space between the tumor and the glossopharyngeal nerve. After that, we can place the SE on the REZ. A method for placement of the ICFN SE is needed for some techniques of AN surgery. Once we learn how to place the SE, we can identify continuous FN function during AN surgery. This method is useful for the preservation of postoperative FN function in AN surgery.