Super-selective balloon test occlusion with electrophysiological monitoring to occlude angiographically invisible posterior communicating artery perforators with unruptured aneurysm.

Balloon test occlusion (BTO) can predict the ischemic complication risk associated with arterial occlusion. We present a case of an unruptured, broad-necked internal carotid artery-posterior communicating artery (PcomA) aneurysm that was successfully embolized after super-selective BTO of fetal PcomA with electrophysiological monitoring. The proximal portion of the PcomA was internally occluded without causing major neurological deficits, although we observed a small new infarction in the ipsilateral anterior thalamus postoperatively. We recognized small perforators arising from the proximal PcomA during a previous clipping surgery. Super-selective BTO with electrophysiological monitoring could be useful for functional preservation after infarction from angiographically invisible perforators.

Octacalcium phosphate collagen composite (OCP/Col) enhance bone regeneration in a rat model of skull defect with dural defect.

Cranial bone defects are a major issue in the field of neurosurgery, and improper management of such defects can cause cosmetic issues as well as more serious infections and inflammation. Several strategies exist to manage these defects clinically, but most rely on synthetic materials that are prone to complications; thus, a bone regenerative approach would be superior. We tested a material (octacalcium phosphate collagen composite [OCP/Col]) that is known to enhance bone regeneration in a skull defect model in rats. Using a critical-sized rat skull defect model, OCP/Col was implanted in rats with an intact dura or with a partial defect of the dura. The results were compared with those in a no-treatment group over the course of 12 weeks using computed tomographic and histological analysis. OCP/Col enhanced bone regeneration, regardless of whether there was a defect of the dura. OCP/Col can be used to treat skull defects, even when the dura is injured or removed surgically, via bone regeneration with enhanced resorption of OCP/Col, thus limiting the risk of infection greatly.

Convection-enhanced delivery of a hydrophilic nitrosourea ameliorates deficits and suppresses tumor growth in experimental spinal cord glioma models.

BACKGROUND: Convection-enhanced delivery (CED) is a technique allowing local infusion of therapeutic agents into the central nervous system, circumventing the blood-brain or spinal cord barrier. OBJECTIVE: To evaluate the utility of nimustine hydrochloride (ACNU) CED in controlling tumor progression in an experimental spinal cord glioma model. METHODS: Toxicity studies were performed in 42 rats following the administration of 4 µl of ACNU CED into the mid-thoracic spinal cord at concentrations ranging from 0.1 to 10 mg/ml. Behavioral analyses and histological evaluations were performed to assess ACNU toxicity in the spinal cord. A survival study was performed in 32 rats following the implantation of 9 L cells into the T8 spinal cord. Seven days after the implantation, rats were assigned to four groups: ACNU CED (0.25 mg/ml; n = 8); ACNU intravenous (i.v.) (0.4 mg; n = 8); saline CED (n = 8); saline i.v. (n = 8). Hind limb movements were evaluated daily in all rats for 21 days. Tumor sizes were measured histologically. RESULTS: The maximum tolerated ACNU concentration was 0.25 mg/ml. Preservation of hind limb motor function and tumor growth suppression was observed in the ACNU CED (0.25 mg/ml) and ACNU i.v. groups. Antitumor effects were more prominent in the ACNU CED group especially in behavioral analyses (P < 0.05; log-rank test). CONCLUSIONS: ACNU CED had efficacy in controlling tumor growth and preserving neurological function in an experimental spinal cord tumor model. ACNU CED can be a viable treatment option for spinal cord high-grade glioma.

Traumatic Spinal Perimedullary Arteriovenous Fistula Induced by a Cervical Glass Stab Injury.

BACKGROUND: In the literature, perimedullary arteriovenous fistula (AVF) is an uncommon spinal vascular malformation that is generally regarded as a congenital lesion. To our knowledge, only a few cases of traumatic perimedullary AVF have been reported in the literature so far. CASE DESCRIPTION: A 58-year-old man presented with subarachnoid hemorrhage (SAH) resulting from a secondary perimedullary arteriovenous fistula (AVF) induced by a glass stab injury to his right posterior neck. The glass had been removed, and the lacerated dura mater was closed. Hydrocephalus was diagnosed 2 months later, and the patient underwent ventriculoperitoneal shunt placement. Magnetic resonance imaging and digital subtraction angiography subsequently revealed dissection of the extradural right vertebral artery. However, there were no signs of perimedullary AVF. The patient presented 9 months after injury with sudden onset of severe headache, and SAH was diagnosed. Repeat digital subtraction angiography showed that the right vertebral artery dissection remained unchanged and was unlikely to be the underlying cause of SAH. However, a new diagnosis of perimedullary AVF at the craniocervical junction was made, and this was considered as a potential cause of SAH. The lesion was surgically obliterated. The hemosiderin deposits on the surface of the spinal cord confirmed that perimedullary AVF was the origin of SAH. CONCLUSIONS: Cervical trauma should be considered as a possible cause of de novo perimedullary AVF. Recognition of this phenomenon is important.

Nasal cavity epithelioid hemangioendothelioma invading the anterior skull base.

BACKGROUND: Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor that frequently occurs in soft tissues. Patients suffer from local recurrence and remote metastasis because of its malignant potential. Here, we present a rare case of EHE that originated from nasal cavity and invaded intracranially through the anterior skull base. CASE DESCRIPTION: This is a 27-year-old woman who presented a local physician with intermittent epistaxis and a facial pain around her nose. Preoperative studies demonstrated that the tumor invaded into anterior skull base and the dura matter. Therefore, we performed combined skull base and transnasal surgery, which achieved complete resection of the tumor. Postoperative course of the patient was uneventful. No recurrence or distant metastasis was observed in the patient for 2 years following the radical resection. CONCLUSIONS: To date, four cases of EHE in the nasal cavity were reported. This is the first case in which EHE demonstrated invasive potentials with intracranial extension. Radical surgical resection plays an important role for better management of invasive paranasal EHE.

Properties of convective delivery in spinal cord gray matter: laboratory investigation and computational simulations.

OBJECT Convection-enhanced delivery (CED) is a method for distributing small and large molecules locally into the interstitial space of the spinal cord. Delivering these molecules to the spinal cord is otherwise difficult due to the blood-spinal cord barrier. Previous research has proven the efficacy of CED for delivering molecules over long distances along the white matter tracts in the spinal cord. Conversely, the characteristics of CED for delivering molecules to the gray matter of the spinal cord remain unknown. The purpose of this study was to reveal regional distribution of macromolecules in the gray and white matter of the spinal cord with special attention to the differences between the gray and white matter. METHODS Sixteen rats (F344) underwent Evans blue dye CED to either the white matter (dorsal column, 8 rats) or the gray matter (ventral horn, 8 rats) of the spinal cord. The rates and total volumes of infusion were 0.2 µl/min and 2.0 µl, respectively. The infused volume of distribution was visualized and quantified histologically. Computational models of the rat spinal cord were also obtained to perform CED simulations in the white and gray matter. RESULTS The ratio of the volume of distribution to the volume of infusion in the gray matter of the spinal cord was 3.60 ± 0.69, which was comparable to that of the white matter (3.05 ± 0.88). When molecules were injected into the white matter, drugs remained in the white matter tract and rarely infused into the adjacent gray matter. Conversely, when drugs were injected into the gray matter, they infiltrated laterally into the white matter tract and traveled longitudinally and preferably along the white matter. In the infusion center, the areas were larger in the gray matter CED than in the white matter (Mann-Whitney U-test, p < 0.01). In computational simulations, the aforementioned characteristics of CED to the gray and white matter were reaffirmed. CONCLUSIONS In the spinal cord, the gray and white matter have distinct characteristics of drug distribution by CED. These differences between the gray and white matter should be taken into account when considering drug delivery to the spinal cord. Computational simulation is a useful tool for predicting drug distributions in the normal spinal cord.

[Endovascular trapping using a tandem balloon technique for a spontaneous vertebrovertebral fistula associated with neurofibromatosis type 1].

We report a rare case of a young man who had spontaneous left vertebrovertebral fistula associated with neurofibromatosis Type 1. His complaints were severe pain in the left neck and numbness in the left upper extremity. Cervical MR images showed a large abnormal flow void to the left of the spinal canal. An angiogram demonstrated a fusiform aneurysm and a high flow arteriovenous fistula in the left vertebral artery that drained into the internal vertebral plexus and formed a large venous varix. The occipital artery, the thyrocervical artery and the contralateral vertebral artery were associated with the fistula. The arteriovenous fistula was treated by endovascular coil embolization, using a tandem balloon technique. For this fistula, exhibiting the combination of high flow and multiple associated arteries, the flow control technique during the coil embolization, using tandem balloons in both the subclavian artery and the distal portion of the fistula of the vertebral artery, was safe and feasible for preventing coil migration.