A Novel Approach of Navigation-Assisted Flexible Neuroendoscopy.

BACKGROUND AND IMPORTANCE: Neuronavigation-assisted endoscopy is commonly used for skull base and intraventricular surgery. Flexible neuroendoscopy offers certain advantages over rigid endoscopy; however, a major disadvantage of the flexible endoscope has been easy disorientation in the flexed position. Neuronavigation-assisted flexible neuroendoscopy was not available until now. This is the first report of the use of navigation-assisted flexible neuroendoscopy in a patient with hydrocephalus. CLINICAL PRESENTATION: A 10-mo-old girl presented with irritability and vomiting to the emergency department and was found to have severe hydrocephalus. The patient underwent successful endoscopic third ventriculostomy and exploration of the ventricles (lateral, third, cerebral aqueduct, fourth) and basal cisterns with the flexible neuroendoscopy assisted with electromagnetic neuronavigation. CONCLUSION: As demonstrated by this initial experience, neuronavigation-assisted flexible neuroendoscopy is a feasible and safe tool, endoscopic procedures with the flexible endoscope may be possible in a safer manner. We report the first use of neuronavigation-assisted flexible neuroendoscopy to perform an ETV and exploration of the entire ventricular system. Further evaluation will be necessary to define and expand its applications in neurosurgery.

Transventricular neuroendoscopic exploration and biopsy of the basal cisterns in patients with Basal meningitis and hydrocephalus.

BACKGROUND: Management of communicating hydrocephalus associated with infectious meningitis and arachnoiditis of the basal cisterns can be challenging if no microorganism or pathological diagnosis is established. The purpose of our series is to elucidate the efficacy of endoscopic basal cistern exploration, biopsy, and endoscopic third ventriculostomy (ETV) in patients with basal cistern meningitis and hydrocephalus. METHODS: Between 2005 and 2010, all patients who underwent transventricular endoscopic exploration biopsy and biopsy of the basal cisterns were analyzed and prospectively followed up. Particular attention was given to neuroendoscopic findings, sensitivity of biopsy, and the role of ETV. RESULTS: Twenty-four patients, ranging in age from 2 to 63 years, underwent transventricular endoscopic biopsy and exploration of the basal cisterns. All patients had negative cerebrospinal fluid analysis obtained by lumbar puncture. Successful ETV, exploration, dissection, and biopsy of the basal cisterns were performed successfully in all patients with a flexible neuroendoscope. Neuroendoscopic findings included: unusually thick Liliequist membrane, moderate to severe adhesive arachnoiditis, inflammatory and cotton-like exudates, granulations, and narrow subarachnoid space. Definitive histopathological diagnosis from the basal cisterns specimen was obtained in 79% of patients. There were no complications related to the procedure. At 15 months of follow-up, 70% of the patients with hydrocephalus did not require a ventriculoperitoneal shunt. CONCLUSIONS: Endoscopic transventricular basal cisterns exploration is feasible with a flexible neuroendoscope. It is a viable alternative in the management of patients with basal cistern meningitis and arachnoiditis without histopathological diagnosis. It yields to an accurate diagnosis in 79% of the patients. ETV is a good alternative in the management of intracisternal extraventricular obstructive hydrocephalus.

Endoscopic management of hydrocephalus due to neurocysticercosis.

OBJECTIVE: Hydrocephalus due to neurocysticercosis usually shows poor prognosis and shunt failure is a common complication. Neuroendoscopy has been suggested as treatment, but the indications remain unclear. METHODS: A cohort of patients with clinical/radiological diagnosis of hydrocephalus due to NCC, treated between January 2002 and September 2006, were the subjects of the study. We excluded patients with tumors or those in whom diagnosis was not confirmed (histology/positive ELISA in CSF). Neuroendoscopy was offered as the first line of treatment. Shunt failure rate and Karnofsky index at 12 months were assessed. RESULTS: Eighty-six patients (47 male) with a median age of 38 (9-79) were included in the study. Of them, 36.1% had a shunt before endoscopy and 97.7% had a Karnofsky index <80. We did not find the parasite in 18.6%, extraction was achieved in 79%, and in 87.2% an endoscopic third ventriculostomy (ETV) was performed. The median follow-up time was 43 months (1-72). Shunt failure was seen in 6.6% of patients with ETV in comparison to 27.2% in those without ETV. A hazard ratio of 0.22 (95% CI, 0.05-0.93) for shunt failure after ETV was calculated. At 12 months, 20.9% had a Karnofsky index <80. CONCLUSION: Early extraction of parasite plus ETV might allow improving outcome and reducing shunt failure. Limitation of inflammatory stimulation by parasite antigens and improvement of CSF dynamics could be an explanation for these findings.

Coexistent intraventricular abnormalities in periventricular giant arachnoid cysts.

OBJECT: Arachnoid cysts are congenital lesions that arise during development by splitting of the arachnoid membrane. Large cysts can be adjacent to CSF pathways causing a marked midline shift and hydrocephalus. The association between a large arachnoid cyst and hydrocephalus has been commonly described as being due to a mass effect, but these previous reports have not focused closely on any associated intraventricular abnormalities. METHODS: Seven patients who were previously treated with a cystoperitoneal shunt presented with shunt failure, hydrocephalus, and/or cyst expansion. All of these patients had giant arachnoid cysts extending to the periventricular region from the original site, which was the sylvian fissure in 4 patients, and the suprasellar cistern, quadrigeminal cistern, and interhemispheric fissure in 1 patient each. Endoscopic exploration of the ventricular system and cyst fenestration was then performed in all patients. RESULTS: The endoscopic findings were obstruction of the cerebral aqueduct by a membrane not related to the cyst in 5 patients, occlusion of the foramen of Monro in 6, septum pellucidum hypoplasia in 2, and occlusion of the cerebral aqueduct by a quadrigeminal arachnoid cyst in 1. Endoscopic procedures performed were septum pellucidum fenestration and/or foraminoplasty in 5 patients, aqueductoplasty in 2, endoscopic third ventriculostomy in 5, fenestration of the lamina terminalis in 1, and direct cystocisternostomy in 1. After the endoscopic procedure, signs and symptoms of increased intracranial pressure and hydrocephalus improved in all patients, with a reduction in size of the cyst and the ventricle. CONCLUSIONS: Ventricular abnormalities contributing to hydrocephalus may be associated with arachnoid cysts. These abnormalities may more likely reflect a common origin than a casual relation. Foramen of Monro stenosis and cerebral aqueduct occlusion associated with an arachnoid cyst can be more frequent than has been previously believed. In cases of periventricular giant arachnoid cysts, endoscopic exploration is a good alternative for examining the ventricular system and identifying and treating CSF obstructions caused by and/or related to arachnoid cysts.

[Observation of the ventricular system and subarachnoid space in the skull base by flexible neuroendoscopy: normal structures]. / Observación del sistema ventricular y espacio subaracnoideo de la base del cráneo por neuroendoscopia flexible: Estructuras normales.

Worldwide in the last two decades, in Latin America in the last decade, and Mexico in particular cerebral endoscopy as part of the minimally invasive neurological surgery, has constituted a significant advance for the treatment of neurological diseases such as congenital or acquired hydrocephalus, Chiari malformation, neurocysticercosis, stroke, ventricular and paraventricular tumors and cysts, arachnoidal cyst and hydrocephalus secondary to shunt malfunction. The lateral ventricles, the third ventricle, the cerebral aqueduct, the fourth ventricle, and the subarachnoid basal cisterns are among the most non-accessible regions of the central nervous system. Due to light-rand fiber optic-systems in combination with the experiences of nine consecutive year's and more than 600 endoscopies, most of them flexible neuroendoscopies, we present the neuroendoscopic approach with flexible cerebral endoscope to the anatomy and its normal variants of the whole ventricle system and the subarachnoid basal cisterns including the subarachnoid space of the cervical spine. We also describe their site related structures including veins, arteries, cranial nerves, pituitary gland, choroidal plexus and their normal anatomic variants.