Complete resection of dual ependymoma spinal metastasis using a fixed tubular retractor-a pediatric case report.

There are no specific guidelines regarding best treatment for focal, distant metastasis in ependymoma in the context of a well-controlled primary site. A combination using maximal safe resection and adjuvant radiotherapy is usually advised. As wound healing might be hindered by repeated radiotherapy, and delay future radiation treatment if needed, there is a growing interest in less invasive surgeries to reduce post-operative pain and wound healing complications. Those approaches have been extensively used and studied in adult but never in the pediatric population. Here, we present a pediatric case of a 12-year-old boy known for a posterior fossa ependymoma completely resected 18 months earlier who presented with a dual lumbosacral intradural ependymoma metastasis. A single-stage complete resection was achieved using a fixed tubular retractor with no complication. Post-operative course was favorable with rapid healing and discharge, minimal post-operative pain, and a rapid return to normal activities. Re-irradiation could be performed 2 weeks later without any problem. To our knowledge, this is the first report of the use of minimally invasive techniques to achieve complete resection of dual intradural metastasis of an ependymoma in the pediatric population. We demonstrate its feasibility and safety as well as its advantages.

Angiographic Analysis of Natural Anastomoses between the Posterior and Anterior Cerebral Arteries in Moyamoya Disease and Syndrome.

BACKGROUND AND PURPOSE: Moyamoya disease is a chronic neurovascular steno-occlusive disease of the internal carotid artery and its main branches, associated with the development of compensatory vascular collaterals. Literature is lacking about the precise description of these compensatory vascular systems. Usually, the posterior circulation is less affected, and its vascular flow could compensate the hypoperfusion of the ICA territories. The aim of this study was to describe these natural connections between the posterior cerebral artery and the anterior cerebral artery necessary to compensate the lack of perfusion of the anterior cerebral artery territories in the Moyamoya population. MATERIALS AND METHODS: All patients treated for Moyamoya disease from 2004 to 2018 in 4 neurosurgical centers with available cerebral digital subtraction angiography were included. Forty patients (80 hemispheres) with the diagnosis of Moyamoya disease were evaluated. The presence of anastomoses between the posterior cerebral artery and the anterior cerebral artery was found in 31 hemispheres (38.7%). RESULTS: Among these 31 hemispheres presenting with posterior cerebral artery-anterior cerebral artery anastomoses, the most frequently encountered collaterals were branches from the posterior callosal artery (20%) and the posterior choroidal arteries (20%). Another possible connection found was pio-pial anastomosis between cortical branches of the posterior cerebral artery and the anterior cerebral artery (15%). We also proposed a 4-grade classification based on the competence of these anastomoses to supply retrogradely the territories of the anterior cerebral artery. CONCLUSIONS: We found 3 different types of anastomoses between the anterior and posterior circulations, with different abilities to compensate the anterior circulation. Their development depends on the perfusion needs of the territories of the anterior cerebral artery and can provide the retrograde refilling of the anterior cerebral artery branches.

Anatomic and Angiographic Analyses of Ophthalmic Artery Collaterals in Moyamoya Disease.

BACKGROUND AND PURPOSE: Moyamoya disease is a progressive neurovascular pathology defined by steno-occlusive disease of the distal internal carotid artery and associated with the development of compensatory vascular collaterals. The etiology and exact anatomy of vascular collaterals have not been extensively studied. The aim of this study was to describe the anatomy of collaterals developed between the ophthalmic artery and the anterior cerebral artery in a Moyamoya population. MATERIALS AND METHODS: All patients treated for Moyamoya disease from 2004 to 2016 in 4 neurosurgical centers with available cerebral digital subtraction angiography were included. Sixty-three cases were evaluated, and only 38 met the inclusion criteria. Two patients had a unilateral cervical internal carotid occlusion that limited analysis of ophthalmic artery collaterals to one hemisphere. This study is consequently based on the analysis of 74 cerebral hemispheres. RESULTS: Thirty-eight patients fulfilled the inclusion criteria. The most frequently encountered anastomosis between the ophthalmic artery and cerebral artery was a branch of the anterior ethmoidal artery (31.1%, 23 hemispheres). In case of proximal stenosis of the anterior cerebral artery, a collateral from the posterior ethmoidal artery could be visualized (16 hemispheres, 21.6%). One case (1.4%) of anastomosis between the lacrimal artery and the middle meningeal artery that permitted the vascularization of a middle cerebral artery territory was also noted. CONCLUSIONS: Collaterals from the ophthalmic artery are frequent in Moyamoya disease. Their development depends on the perfusion needs of the anterior cerebral artery territories. Three other systems of compensation could be present (callosal circle, leptomeningeal anastomosis, and duro-pial anastomoses).

Exophytic bulbar pilocytic astrocytoma and post-operative cerebral salt wasting syndrome.

Cerebral salt wasting syndrome (CSWS) is a well-described consequence of several neurological disorders. Although the exact etiology of CSWS is still not completely elucidated, it is believed that the hypothalamus plays a pivotal role in the genesis of this disorder. We report for the first time 3 cases of CSWS occurring during the post-operative course following surgical resection of exophytic bulbar pilocytic astrocytomas in children. Since these 3 cases shared in common a medial implication of the medulla, we suggest that specific interconnectivity between the dorso-medial portion of the medulla oblongata and the hypothalamus might thus represent an anatomical pathway of interest in the pathogenesis of CSWS. Our findings suggest that the resection of medially located exophytic bulbar tumors might constitutes a risk factor in the development of CSWS. Particular care should thus be carried towards the prompt detection and treatment of CSWS in the post-operative courses of exophytic bulbar tumors.

Mini-open oblique lumbar interbody fusion (OLIF) approach for multi-level discectomy and fusion involving L5-S1: Preliminary experience.

STUDY DESIGN: Technical description and single institution retrospective case series. OBJECTIVE: Evaluate technical feasibility and evaluate complications of mini-open retroperitoneal oblique lumbar interbody fusion (OLIF) at the L5-S1 level. SUMMARY OF BACKGROUND: The mini-open retroperitoneal oblique lumbar interbody fusion (OLIF) approach was first described in 2012 as a surgical approach to achieve spinal fusion while limiting invasiveness of the exposure to the anterior lumbar spine. Surgeons who use this approach, along with those who described it in cadaveric studies describe it as a feasible approach in targeting the L2 down to the L5 level and recommend alternative approaches to the L5-S1 level due to the vascular challenges and possible complications. METHODS: Technical description and single institution case series of patients treated with the OLIF between 2013 and 2015 at the L5-S1 level. The previously described surgical approach was modified by identifying and ligating the iliolumbar vein before retracting the iliac artery and vein anteriorly instead of passing between the vessels. RESULTS: Six patients (3 males, 3 females, mean age 62 years) were operated between 2013 and 2015. There were no vascular injuries or peripheral nerve trauma associated with the surgical procedure. Complications associated with the procedure included: cage displacement immediately postoperative requiring re-operation in one patient, transient psoas weakness in one patient, extended hospital stay for pain control in one patient, and transfusion was required in one patient. CONCLUSIONS: Mini-open retroperitoneal oblique lumbar interbody fusion is feasible at the L5-S1 level with limited vascular complications through a technical modification for safe mobilization of the iliac vessels by first ligating the iliolumbar vein.

Angiographic pitfall: duplicated tapered A1 segment of the anterior cerebral artery mimicking an anterior communicating artery aneurysm.

We describe a misleading case of a partially occluded A1 segment duplication that mimicked an ACoA aneurysm on computed tomography angiography and conventional angiography and led to surgical intervention. The location of such an anomaly at the ACoA on the side of least hemodynamic stress may provide a clue to recognizing this variant.

[Insular epilepsy: The Montreal experience]. / L'épilepsie insulaire : l'expérience montréalaise.

In this article, we review recently published data on the role of the insula in refractory partial epilepsy and summarize our own experience in the investigation and treatment of this entity. Case studies and evoked responses obtained from insular cortical stimulation reveal a wide array of clinical manifestations which may mimic temporal, frontal or parietal lobe seizures. Clinicians should hence lower their threshold to sample the insula with intracerebral electrodes. Lack of recognition of insular seizures may explain part of epilepsy surgery failures. Advances in microneurosurgery open the way to safer insular resection.