Syringosubarachnoid shunting with augmented reality navigation through a keyhole laminectomy of the upper thoracic spine: illustrative case.

BACKGROUND: A syringosubarachnoid (SS) shunt combined with keyhole hemilaminectomy is a beneficial procedure that can reduce the size of the skin incision and the risk of complications. However, ingenuity is needed to confirm the position of the syrinx during surgery. The authors present a case in which they treated syringomyelia in the upper thoracic spine using augmented reality (AR) to confirm syrinx formation, bone resection, and skin incision. OBSERVATIONS: Microscope-based AR was an appropriate and practical choice in this case. By placing the reference array at the Mayfield clamp, it was possible to use AR from the point of skin incision. Under AR navigation, an SS shunt tube can be placed in the short syrinx. LESSONS: AR navigation enables pinpoint SS shunt tube insertion with minimal skin incision and bone resection. It is particularly useful for upper thoracic and small syrinx lesions. https://thejns.org/doi/10.3171/CASE24130.

Case report: Usefulness of angioscopy in determining antiplatelet drug reduction after carotid artery stenting.

We report a case in which neointima was confirmed by angioscopy and antiplatelet drug administration was reduced 2 months after carotid artery stenting (CAS). A patient in their 80s was scheduled to undergo resection for renal cancer; however, he also had right cervical internal carotid artery stenosis. Because this was a risk for general anesthesia, CAS was performed after first starting dual antiplatelet therapy. Urologically, early reduction of antiplatelet drugs was necessary for a nephrectomy. Although no obvious neointima could be identified on ultrasound 2 months after CAS, thin neointima was observed using angioscopy. Based on the above results, we reduced the antiplatelet drug administration, and then the nephrectomy was performed. Ultimately, no cerebral infarction occurred in the perioperative or postoperative periods. Angioscopy allows for visual confirmation of thin neointima. If sufficient neointima can be confirmed, antiplatelet drug reduction can be performed more safely and reliably.

A Case of Concomitant Lip Injury and Facial Pressure Ulcer in Lumbar Intradural Tumor Surgery With Repeated Transcranial Electrical Stimulations.

Transcranial motor evoked potential (MEP) is a common method in spinal surgery but requires strong electrical stimulation. Frequent transcranial stimulations can cause bite injury. In addition, a facial pressure ulcer is a problem in spinal surgery requiring prone positioning. We present a case of bite injury and facial pressure ulcer in prolonged lumbar tumor surgery with repeated transcranial stimulations. A 74-year-old woman developed left lower limb and low back pain. MRI revealed an intradural extramedullary tumor at L1. We performed tumor resection surgery. A silicon bite block was used, and the patient's head was placed on a sponge headrest. The tumor was a schwannoma originating from the nerve root that innervated the left anal sphincter. Intracapsular resection was performed while referring to the frequent transcranial MEP monitoring. The left lower limb and low back pain improved after surgery; however, lip injury and facial skin ulcer occurred. The face showed marked swelling and was painful, so oral intake was difficult for a week. Wound healing was obtained three months postoperatively, but hypoesthesia remained. When using MEP in prolonged spine surgery with a headrest, it is necessary to pay attention to both bite injury and facial pressure ulcer. Intraoperative assessment of the face, number of transcranial stimulations, types of a bite block, and headrest may be important.

Navigation-assisted full-endoscopic spine surgery: a technical note.

BACKGROUND: Full-endoscopic spine surgery (FESS) necessitates the use of X-ray fluoroscopy for intraoperative guidance and orientation. However, the two-dimensional X-ray fluoroscopic images do not provide real-time guidance. The authors developed a new real-time three-dimensional (3D) navigation technique for FESS that entails the use of intraoperative cone beam computed tomography (CBCT) in a hybrid operating room (OR). METHODS: A total of 23 patients undergoing FESS using real-time 3D navigation system were enrolled. Preoperative and intraoperative CBCT data were registered in the navigation system. The 3D navigation was used to intraoperatively determine the trajectory and obtain position information. The feasibility and usefulness of the navigation system were retrospectively analyzed. RESULTS: Twenty patients had lumbar spine disease, whereas three patients had cervical spine disease. The 3D navigation was successfully used for intraoperative guidance and provided accurate information in all patients. X-ray fluoroscopy was not required in any of the patients. No complications associated with the use of 3D navigation system were encountered. CONCLUSIONS: The use of real-time 3D navigation system in the hybrid OR was found to be safe and effective in providing intraoperative guidance for FESS.

Intradural Disk Herniation Mimicking a Spinal Tumor: Radiologic Imaging, Pathogenesis, and Operative Management.

Intradural disk herniation (IDH) is a rare condition, occurring more often at the L4-5 level. We examined a case of an IDH at the L1-2 level mimicking an intradural spinal tumor. A 71-year-old woman with a long history of backache and pain radiating down the left leg was admitted to our hospital with the worsening of these symptoms. Magnetic resonance imaging and computed tomographic myelography demonstrated an intradural mass at the L1-2 level. Given the radiologic findings and the location of the mass, the preoperative differential diagnosis centered on intradural spinal tumors. Dural incision was performed using a surgical microscope to resect the mass. Contrary to our expectation, the diagnosis made during the surgery was IDH. Despite advances in imaging techniques, IDH could not be definitively diagnosed preoperatively. The pathogenesis of IDH remains unclear. In our patient, the ventral dural defect was smooth and round, and the dural tissue around the defect was thickened. These intraoperative findings suggested that the patient's IDH resulted not from an acute new event but from a chronic process. We recommend dural incision using a surgical microscope for treating IDH because it provides a clear visual field.

[A Case of a Pituitary Adenoma Diagnosed as Carney Complex Syndrome in an Older Female Patient].

Carney complex syndrome is an autosomal dominant familial tumor syndrome first described by Carney et al. in 1985. The diagnostic criteria include endocrine hyperactivity and spotty skin pigmentation. A 73-year-old woman with cerebral infarction was referred to our department because her brain magnetic resonance imaging(MRI)revealed a pituitary tumor. Her blood tests revealed elevated levels of growth hormone(GH), thyroid stimulating hormone(TSH), and insulin-like growth factor-1(IGF-1). We suspected the presence of a GH-secreting tumor and performed the operation. The pathological finding was a TSH-positive pituitary adenoma. Her cervical computed tomography(CT)revealed a thyroid tumor and the tumor removal was performed. The pathological diagnosis was papillary carcinoma. She had skin pigmentation bilaterally on her face, forearms, hands, and legs. We diagnosed this case as Carney complex syndrome based on these findings.

Safety and tolerability of navigated TMS for preoperative mapping in neurosurgical patients.

OBJECTIVE: Navigated transcranial magnetic stimulation (nTMS) is a non-invasive technique for pre-surgical motor and language mapping in patients with brain lesions. This study examines the safety and tolerability of nTMS in a large, multi-center cohort of neurosurgical patients. METHODS: Functional mapping with monopulse and repetitive nTMS was performed in 733 patients. In this cohort, 57% of patients had left-sided tumors, 50% had frontal tumors, and 50% had seizures secondary to the lesion. Side effects and pain intensity related to the procedure were documented. RESULTS: Patients undergoing monopulse stimulation underwent an average of 490 pulses while those undergoing repetitive stimulation received an average of 2268 pulses. During monopulse stimulation, 5.1% reported discomfort (VAS 1-3), and 0.4% reported pain (VAS>3). During repetitive stimulation, 23.4% reported discomfort and 69.5% reported pain. No seizures or other adverse events were observed. CONCLUSIONS: nTMS is safe and well-tolerated in neurosurgical patients. Clinicians should consider expanding nTMS to patients with frequent seizures, but more evaluation is necessary to evaluate this risk fully. SIGNIFICANCE: nTMS is safe and well-tolerated, even in neurosurgical patients with persistent occasional seizure secondary to a lesion. It should be considered in any patient with a lesion in a presumed peri-eloquent or eloquent brain region.

Intradural extramedullary ganglioneuroma associated with multiple hamartoma syndrome.

A 51-year-old woman presented with a rare completely intradural and extramedullary spinal ganglioneuroma associated with multiple hamartoma syndrome and manifesting as complaints of neck pain and dizziness persisting for 8 months. Magnetic resonance imaging of the spinal cord revealed an intradural extramedullary lesion at the C1 level. She underwent right suboccipital craniectomy and C1-2 hemilaminectomy to remove the tumor. Histological examination confirmed ganglioneuroma. She also suffered from multiple facial trichilemmomas, thyroid goiter, multiple polyposis of the gastrointestinal tract, and pulmonary hamartoma indicating multiple hamartoma syndrome. These benign neoplasms were treated conservatively.

Dural repair for intraspinal extradural meningeal cyst.

A 52-year-old woman presented with an intraspinal extradural meningeal cyst in the thoracolumbar region manifesting as progressive sensory disturbance of the bilateral lower extremities. Magnetic resonance imaging and computed tomography myelography showed an extradural meningeal cyst extending from the T-12 to L-4 levels in the thoracolumbar region with a dural defect and a valve-like mechanism developed in the enlarging cyst. Operative findings revealed a dural defect that allowed communication between the extradural cyst cavity and the subarachnoid space. Surgical resection of the cyst wall and repair of the dural defect resolved the symptoms.

Expression of angiogenic growth factor in the rat DAVF model.

OBJECTIVE: The precise mechanisms responsible for the development and growth of dural arteriovenous fistula (DAVF) remain unclear, but it has been hypothesized that vascular endothelial growth factor (VEGF) might be involved in the pathogenesis. The aim of this study was to examine the expression of VEGF in the rat DAVF model. METHODS: Forty-five Sprague-Dawley rats were used in two experiments. In Experiment 1 (n = 20, including sham-operated controls), VEGF expression was analysed by Western blots in three different rat DAVF models: model I: common carotid artery-external jugular vein (CCA-EJV) anastomosis (n = 5); model II: sagittal sinus thrombosis and bipolar coagulation of the vein draining the transverse sinus (n = 5); model III: CCA-EJV anastomosis and bipolar coagulation of the vein draining the transverse sinus and sagittal sinus thrombosis to induce venous hypertension (n = 5). Based on the results of Experiment 1, Western blots were performed at weekly intervals 1, 2 and 3 weeks in Experiment 2 following induction of venous hypertension in model III (n = 5 at each time point and n = 5 sham controls); in addition, VEGF expression was immunohistochemically examined in the dura and the brain near the occluded sinus in five model III animals after 1 week. RESULTS: In Experiment 1, Western blot analysis showed barely detectable bands with molecular weights of 45 kD, corresponding to VEGF, in the sham group, but the highest level of VEGF was induced in model III, followed by models I and II (model III>model I>model II). In Experiment 2, the expression of VEGF peaked 1 week after induction of venous hypertension in model III, decreasing in a linear fashion over 2 and 3 weeks (week 1>weeks 2 and 3). The expression of immunoreactive VEGF was restricted in the connective tissue and the endothelial layer of the dura matter, cerebral cortical tissue and neurons of the basal ganglia. CONCLUSION: Our results strongly suggest a possible contribution of an angiogenic factor to the growth of DAVF. Venous ischemia by venous hypertension might be a mechanism for inducing up-regulation of angiogenic factor expression.

Long-term outcome of unruptured giant cerebral aneurysms.

The long-term outcome of 39 patients with unruptured giant aneurysm (>2.5 cm) treated during the last 12 years was retrospectively reviewed. The 7 male and 32 female patients, aged 32 to 81 years, presented with symptoms related to compression of the surrounding structures by the aneurysm in 28 cases, cerebral infarction in one, and asymptomatic in 10. The locations were the internal carotid artery (ICA) in 27 cases, middle cerebral artery in three, anterior cerebral artery in one, and basilar artery in eight. Therapeutic modalities were direct clipping in 11 patients, ICA occlusion combined with extracranial-intracranial bypass in 15, and conservative treatment in 13. The follow-up period ranged from 16 to 128 months (mean 54.0 months). The mortality was 9% (1/11), 0% (0/15), and 31% (4/13), and morbidity was 18% (2/11), 20% (3/15), and 8% (1/13), respectively. Surgery reduced the mortality (from 31% to 4%) but increased the morbidity (from 8% to 19%) as compared with conservatively treated patients (p < 0.05). Giant intracranial aneurysm has a poor prognosis if left untreated, but these lesions are difficult to treat with the present management options.

[Extracranial vertebral artery dissection repeating distal embolism: case report].

We report a case of vertebral artery (VA) dissection presenting with repeated distal embolism. A 48-year-old man was admitted to our institution with neck pain and vertigo of two day duration. MRI on arrival showed infarction of the left cerebellar hemisphere and the right occipital lobe. Emergency angiography revealed left VA dissection and occlusion of the left posterior inferior cerebellar artery and right calcaline artery. Six hours after admission, he manifested cortical blindness due to embolism of the contralateral left calcaline artery despite giving heparin and aspirin. Thrombolysis was performed but was not successful. We embolized the affected VA to prevent further embolism. We discuss here the indication and timing of treatment for VA dissection presenting with ischemic symptom.

[Vascular endothelial growth factor expression in the rat dural arteriovenous fistula model].

UNLABELLED: Although various mechanisms of the development of dural arteriovenous fistula (DAVF) have been proposed, the pathogenesis of these lesions are still unclear. Recent experimental evidence suggested a role of angiogenic growth factors in the genesis of vascular malformations of the central nervous system. To further investigate the pathogenesis of DAVF, we examined the expression of the angiogenic growth factor, vascular endothelial growth factor (VEGF), in rat DAVF model. MATERIAL AND METHODS: Male Wistar rats (weighting 280 to 300 g, n = 40) were used. Each rat was mounted on a stereotaxic frame under general anesthesia. DAVF model (Spetzler et al.) was made by common carotid artery-external jugular vein anastomosis, bipolar coagulation of the vein draining the transverse sinus, and superior sagittal sinus thrombosis (SSS). SSS was thrombosed by a hemostatic agent through 16-gauge needle. Venous hypertension was induced in 30 rats, which were divided into two experimental groups; (1) immunohistological study group (n = 15) and (2) angiography group (n = 15). Immunohistological analysis was performed by VEGF antibody 1 week after, and angiography was done 90 days after the surgery. Developing of angiographical DAVF was observed with the magnifying X-ray camera. Each 5 rats served as sham-operated controls, which received a similar surgery without induction of venous hypertension. RESULTS: VEGF expression and DAVF were not observed in sham group. In immunohistological study group, VEGF expression in the endothelium and the connective tissues of the dura mater in the five rats (33%) and in the neurons in the eleven rats (73%) of the cerebral cortex and the basal ganglia were identified. In angiography group, DAVF formed in 6 among 15 rats (40%). CONCLUSION: The findings of this study provide the first experimental evidence that angiogenic growth factors VEGF may participate in the genesis of DAVF. These results suggest a novel strategy for the management and prevention of DAVF and related disorders.