Extra-Axial Third Ventriculostomy Through Lamina Terminalis with Multiple Cisternostomies - Rescue Surgery for Patients with Failed Shunt Surgeries and Hydrocephalus.

Background and Aim: Contemporary management of hydrocephalus involves various modes of cerebrospinal fluid (CSF) diversion, including shunt surgery and endoscopic ventriculostomy. However, there are times when either of these procedures have either failed or are not feasible. Highly invasive procedures aimed at internal CSF have been described previously, which, with the aid of modern microsurgical techniques, can be attempted in cases with very limited options. Our aim was to study the utility of extra-axial third ventriculostomy via lamina terminalis fenestration with multiple cisternostomies in the treatment of failed hydrocephalus. Materials and Methods: Forty-five patients with hydrocephalus were operated for extra-axial trans-lamina terminalis third ventriculostomy with multiple cisternostomies from January 2017 to January 2019. A minimally invasive supraorbital craniotomy was performed with subfrontal fenestration of the lamina terminalis and trans-lamina terminalis fenestration of the floor of the third ventricle with multiple cisternostomies including the optico-carotid cistern and opening of the Liliequist membrane. Results: Tuberculous meningitis was the most common etiology in the series, and multiple shunt procedures and incompatible CSF profiles were the most common reasons that necessitated this alternate rescue procedure. At a mean follow-up of 6 months, no patient required a revision shunt surgery. There was one death due to cardiac failure with anasarca, unrelated to the procedure. Conclusions: Extra-axial trans-lamina terminalis ventriculostomy with cisternostomies can safely be performed using minimally invasive micro-neurosurgical techniques, adding to the armamentarium of neurosurgeons in the management of complex cases of hydrocephalus.

Prefronto-thalamic tract injury and cognitive outcome according to external ventricular drainage location in stroke patients.

OBJECTIVES: We investigated the characteristics of prefronto-thalamic tract (PF-TT) injuries in stroke patients using diffusion tensor tractography (DTT) and assessing cognitive outcome according to location of the external ventricular drainage (EVD). METHODS: Forty-five consecutive stroke patients who underwent EVD and 24 control subjects were recruited. The patients were classified into three groups: group A (EVD on the lesion or one side, 17 patients), group B (EVD on the hemisphere opposite to the lesion, 12 patients), and group C (EVD on both sides, 16 patients). Mini-Mental State Examination (MMSE) results were performed at the beginning (average 2.27 months from onset) and end (average 4.19 months from onset) of rehabilitation. Three parts of the PF-TT (dorsolateral PF-TT[DLPF-TT], ventrolateral PF-TT[VLPF-TT], orbitofronto-thalamic tract[OF-TT]) were reconstructed and the fractional anisotropy (FA) and tract volume (TV) measurements were obtained. RESULTS: With the EVD on the stroke-affected side, the values of FA and TV of all three parts of the PF-TTs in three patient groups were lower than those of the control group (p < 0.05). With the EVD on the unaffected side, the FA values of the DLPF-TT in groups B and C and the OF-TT in group C were lower than those of the control group (p < 0.05). There was no difference in initial MMSE score among three patient groups; however, group A had a higher mean follow-up MMSE score than that of groups B and C (p < 0.05). CONCLUSIONS: Patients who underwent EVD of the affected hemisphere showed better results in terms of the PF-TT injury and cognitive outcome than patients who underwent EVD through the unaffected hemisphere or through both hemispheres.

Effect of Microscopic Third Ventriculostomy (Lamina Terminalis Fenestration) on Shunt-needed Hydrocephalus in Patients with Aneurysmal Subarachnoid Hemorrhage.

There are reports that in patients with aSAH (aneurysmal subarachnoid hemorrhage), LTF (lamina terminalis fenestration) reduces the rate of shunt-needed hydrocephalus via facilitation of CSF (cerebrospinal fluid) dynamic, diminished leptomeningeal inflammation, and decreased subarachnoid fibrosis. Regarding the conflicting results, this study was conducted to evaluate the effects of LTF on decreased shunt-needed hydrocephalus in patients with aSAH. A cross-sectional retrospective study was carried out to survey all patients with confirmed aSAH operated from March 2011 to September 2016 in an academic vascular center (Rasool Akram Hospital in Tehran, Iran). Of a total of 151 patients, 72 patients were male and 79 were female. The mean age of the participants was 51 years. A transiently CSF diversion (EVD - external ventricular drainage) was performed (the acute hydrocephalus rate) on 21 patients (13.9%). In 36 patients (23.8%), aneurysm occlusion with LTF and in 115 patients (76.2%) only aneurysm occlusion surgery was performed. In hydrocephalus follow-up after surgery, 13 (12%) patients needed shunt insertion (the rate of shunt-needed hydrocephalus). The statistical analysis demonstrated no significant relation between LTF and shunt-needed hydrocephalus. Confirmation of the hypothesis that LTF may decrease the rate of shunt-needed hydrocephalus can significantly decrease morbidity, mortality, and treatment costs of shunting (that is a simple, but a potentially dangerous procedure). So, it is advised to plan and perform an RCT (randomized controlled trial) that can remove the confounding factors, match the groups, and illustrate the exact effect of LTF on shunt-needed hydrocephalus.

Interhypothalamic adhesions in endoscopic third ventriculostomy.

INTRODUCTION: An interhypothalamic adhesion (IHA) is a gray mater-like band of tissue traversing across the third ventricle anterior to the mammillary bodies and is similar but distinct from an interthalamic adhesion. These rare anatomic anomalies can be detected with magnetic resonance imaging or, incidentally, during endoscopic ventricular surgery. METHODS: All cases of interhypothalamic adhesions visualized during endoscopic third ventriculotomy (ETV), outside of the myelomeningocele setting, were identified from two institutions. Retrospective chart and imaging reviews were conducted and compared to intraoperative videos and photos for all cases. IHA variables collected included the following size, location, multiplicity, and associated anatomic anomalies. RESULTS: Four cases of interhypothalamic adhesions were identified during ETV-all of which, either partially or completely, obscured access to the third ventricular floor. The IHAs in our cohort were duplicated in two patients, large (> 3 mm and severely obstructing access to the third ventricular floor) in three patients, and adherent to the floor of the third ventricle in three patients. All four patients had primary absence of the septum pellucidum. Previous reports found associations of IHAs with other congenital, particularly midline, abnormalities. The IHAs in our cohort affected the surgery in three of four cases including misdirecting the ventriculostomy and requiring retraction or division of the IHA. In no case was postoperative pituitary or hypothalamic dysfunction observed. CONCLUSIONS: Although interhypothalamic adhesions are rare, these anomalies must be recognized as they may hinder access to the third ventricular floor. IHAs may be large, multiple, or adherent to adjacent ventricular structures, they can misdirect or occlude the ventriculostomy or impart risk of bleeding and hypothalamic injury. Techniques for management of IHA include aborting the attempt, re-siting the ventriculostomy, or retracting or dividing the IHA, which enabled technically successful ETV in three of four patients in this series.

Cisternal lavage via third ventriculostomy through the fenestrated lamina terminalis after aneurysm clipping: Technical note.

Delayed cerebral infarction (DCI) contributes to the burden of morbidity and mortality acquired by patients with aneurysmal subarachnoid hemorrhage (SAH). Cisternal lavage may prevent DCI. Delivery of lavage therapy to the basal cisterns, however, is challenging. Here, we report a novel method for the delivery of cisternal lavage using a cisterno-ventricular catheter (CVC) inserted via the fenestrated lamina terminalis during aneurysm clipping. In two high-risk aSAH patients a CVC was inserted into the third ventricle through the fenestrated lamina terminalis during aneurysm clipping. Post-operatively, continuous cisternal lavage using Urokinase or Nimodipine was applied using an external ventricular drain (EVD) as inflow tract and the CVC as outflow tract. Neurological outcome at 6 months was assessed by modified Rankin scale. Catheter placement into the third ventricle through the fenestrated lamina terminalis was performed without complications. Application of a free-running electrolyte solution containing Urokinase or Nimodipine via the EVD and drainage via the CVC was feasible. Cisternal Nimodipine application normalized sonographic vasospasm in both cases. DCI did not occur. CVC placement for ventriculo-cisternal lavage may represent a useful method for DCI prevention. It can be considered in aSAH patients at risk for DCI if the chiasmatic region is accessed during aneurysm clipping.

A novel rescue therapy for cerebral vasospasm: Cisternal Nimodipine application via stereotactic catheter ventriculocisternostomy.

Delayed Cerebral Infarction (DCI) due to Cerebral Vasospasm (CVS) is an important contributor to poor outcome after aneurysmal subarachnoid haemorrhage (aSAH). Despite established risk factors CVS and DCI are unpredictable at the individual patient level. Efficient treatments are lacking. We report a novel rescue therapy for DCI: Access to the basal cisterns by stereotactic catheter ventriculocisternostomy (STX-VCS) and direct cisternal application of the spasmolytic agent Nimodipine. On the basis of individual treatment decisions three aSAH patients who developed CVS underwent STX-VCS. Continuous lavage with Nimodipine was performed. CVS was assessed by daily transcranial doppler ultrasonography. Neurological outcome at 3 months was assessed by modified Rankin scale. STX-VCS was performed without complications in all patients. CVS rapidly resolved upon cisternal application of Nimodipine. CVS recurred in two patients upon interruption of Nimodpine application and resolved upon restart of Nimodipine. DCI did not occur in all three cases. STX-VCS and cisternal Nimodipine application is a novel rescue therapy for CVS treatment and DCI-prevention in patients with aSAH.

Effectiveness of Intraventricular Endoscopic Lamina Terminalis Fenestration in Comparison with Standard ETV: Systematic Review of Literature.

BACKGROUND: Endoscopic third ventriculostomy is a consolidated technique for the treatment of hydrocephalus. Despite its effectiveness and feasibility, several technical limitations about its use in certain situations have been described. Lamina terminalis-endoscopic third ventriculostomy (LT-ETV) has been proposed as an alternative technique. Authors systematically reviewed the literature in order to define the effectiveness and limits in comparison with standard ETV. METHODS: This systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. It has also been registered with the PROSPERO International Prospective Register of Systematic Reviews (CRD42016041596). MEDLINE, Web of Knowledge, and EMBASE were independently searched. RESULTS: Seven studies were found to be eligible. A case of ours was added to the series, totaling 41 patients (mean patient age ± SD was 21.6 ± 20.7 years). Endoscopic findings leading surgeons to perform LT-ETV were abnormal ventricular anatomy (24, 57%), inadequate/insufficient interpeduncular subarachnoid space (11, 26%), a combination of both (5, 12%), and intraoperatory, unsatisfactory third ventricle floor fenestration (2, 5%). Most common pathologies were neurocysticercosis (12, 28.57%), aqueductal stenosis (8, 19%), tuberculous meningitis (4, 9.52%), and medulloblastoma (3, 7.14%). A flexible endoscope was the most used device (36 procedures, 86%), while not determining a statistical relevant diminution of complications in comparison with a rigid endoscope (P = 1.0). An overall success rate of 69% was registered, increasing to 89% if just the first year of follow-up was considered. CONCLUSIONS: LT-ETV can be considered a successful technical option when standard ETV cannot be performed, although more complex cerebrovascular anatomy is involved. Therefore we suggest that lateral terminalis fenestration is a valid technical option in experienced hands.

Endoscopic management of a low-grade thalamic glioma: a safe alternative to open microsurgery?

BACKGROUND: Despite considerable advances in preoperative and intraoperative imaging and neuronavigation, resection of thalamic gliomas remains challenging. Although both endoscopic biopsy and third ventriculostomy (ETV) for the treatment of secondary hydrocephalus are commonly performed, endoscopic resection of thalamic gliomas has been very sparsely described. METHOD: We report and illustrate the surgical procedure and patient's outcome after full endoscopic resection of a thalamic glioma and to discuss this approach as an alternative to open microsurgery. RESULTS: In 2016, a 56-year-old woman presented with disorientation, dysphasia and right facial hypaesthesia in our department. Cranial magnetic resonance imaging revealed a left thalamic lesion and subsequent hydrocephalus. Initially, hydrocephalus was treated by ETV but forceps biopsy was not diagnostic. However, metabolism in 18F-fluoroethyl-L-tyrosine positron emission tomography indicated glioma. Subsequently, endoscopic and neuronavigation-guided tumour resection was performed using a <1 cm2, trans-sulcal approach through the left posterior horn of the lateral ventricle. While visibility was poor using the intraoperative microscope, neuroendoscopy provided excellent visualisation and allowed safe tumour debulking. Neither haemorrhage from the tumour or collapse of the cavity compromised endoscopic resection. CONCLUSIONS: In accordance with one previously published case of endoscopic resection of a thalamic glioma, no surgery-related complications were observed. Although this remains to be determined in larger series, endoscopic resection of these lesions might be a safe and feasible alternative to biopsy or open surgery. Future studies should also aim to identify patients specifically eligible for these approaches.

The effect of fenestration of the lamina terminalis on the incidence of shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage (FISH): Study protocol for a randomized controlled trial.

BACKGROUND: Shunt-dependent hydrocephalus (SDH) is a well-known sequela following aneurysmal hemorrhage, adversely affecting the outcome after securing ruptured aneurysm. Fenestration of lamina terminalis (FLT) creates an anterior ventriculostomy, facilitates cerebrospinal fluid circulation and clot clearance in the basal cistern. However, controversy exists over whether microsurgical FLT during aneurysm repair can decrease the incidence of SDH. AIMS: The study is designed to determine the efficacy of lamina terminalis fenestration on the reduction of SDH after aneurysm clipping. METHODS/DESIGN: A total of 288 patients who meet the inclusion criteria will be randomized into single aneurysm clipping or aneurysm clipping plus FLT in the Department of Neurosurgery, West China Hospital. Follow-up was performed 1, 3, 6, and 12 months after aneurysm clipping. The primary outcome is the incidence of SDH and the secondary outcomes include cerebral vasospasm, functional outcome evaluated by the modified Rankin Scale and Extended Glasgow Outcome Scale, and mortality. DISCUSSION: The FISH trial is a large randomized, parallel controlled clinical trial to define the therapeutic value of FLT, the results of which will help to guide the surgical procedure and resolve the long-puzzled debate in the neurosurgical community. CONCLUSIONS: This protocol will determine the efficacy of FLT in the setting of aneurysmal subarachnoid hemorrhage. TRIAL REGISTRATION IDENTIFIER: CHINESE CLINICAL TRIAL REGISTRY:: ChiCTR-INR-16009249.

Flexible Endoscopic Aspiration for Intraventricular Casting Hematoma.

BACKGROUND: Conventionally, patients suffering a massive intraventricular hemorrhage have undergone external ventricular drainage. However, long-term or repeated drainage increases the risk of complications due to infections or shunt dependency. Neuroendoscopic surgery may offer some advantages over more conventional procedures. METHODS: Thirteen patients suffering intraventricular hematoma associated with intracerebral hemorrhage, treated in our hospital between April 2011 and March 2014, were reviewed retrospectively. Casting hematomas in the ventricles were manually aspirated using a flexible endoscope. The timing of the operation, period of post-endoscopic ventricular drainage, additional internal shunt surgery, 3-month post-surgical outcome, and critical complications were evaluated. RESULTS: Two patients (treated during our earliest use of endoscope) who underwent surgery on the 7th and 16th day post-onset required subsequent cerebrospinal shunt surgery. In contrast, of the 11 patients who underwent endoscopic surgery on the day of onset, only 1 patient required an additional, third ventriculostomy due to a secondary obstruction of the aqueduct by adhesive fibrous membranes. After 3 months, all six patients with mRS scores of 2-3 satisfied all the following criteria: initial Glasgow Coma Scale scores higher than 8, flexible endoscopic surgeries performed on the day of onset, and period of ventricular drainage of less than 4 days. CONCLUSIONS: Early surgical intervention using a flexible endoscope and short period of post-surgical drainage can be highly effective for patients suffering from casting intraventricular hematomas associated with intracerebral hemorrhage. The advantages of this treatment may be a less invasive procedure, ICP control in the acute phase, breaking away from ventricular drainage in the early stage, and prevention of hydrocephalus or intracranial infectious complications in the long term.

Endoscopic third ventriculostomy through lamina terminalis: A feasible alternative to standard endoscopic third ventriculostomy.

CONTEXT: Endoscopic third ventriculostomy (ETV), wherein a stoma is created in the floor of the third ventricle, has now become the standard procedure for noncommunicating hydrocephalus across the world. However, in certain situations, this procedure may pose technical difficulties. These include a narrow prepontine space, vascularized third ventricular floor, the presence of prominent blood vessels traversing within the prepontine space, significant basal exudates, thickened and ill-defined third ventricular floor, and distorted floor anatomy. In such situations, an endoscopic lamina terminalis opening may provide a safer and more effective alternative to the standard technique. AIMS: The paper aims to discuss the different indications, technical nuances, and outcome of endoscopic third ventriculostomy through the lamina terminalis (ETV LT) utilizing the standard transventricular transforaminal route. SETTINGS AND DESIGN: A total of 240 patients underwent ETV between January 2007 and January 2014. Of these patients, 8 patients required an EVT LT and these patients formed the subset of patients for the present study. In all the 8 patients, the decision to perform fenestration of the LT during the endoscopic procedure was taken intraoperatively. We qualified a procedure to be a success when a second procedure was not required subsequently. RESULTS: Of the eight patients in whom ETV LT was done, four had aqueductal stenosis (including one case of post-primary ETV), three patients were diagnosed with post-meningitic hydrocephalus, and the remaining patient had a posterior fossa tumor. The procedure was successful in 6 of our patients who did not require a second procedure till the last follow-up. CONCLUSIONS: Endoscopic transventricular transforaminal LT fenestration with a flexible neuroendoscope is a feasible alternative to the standard ETV when technical difficulties precludes safe performance of the latter procedure.

Biphasic response of a tecto-mesencephalic pilocytic astrocytoma after Gamma Knife surgery--A case report.

Biphasic response (shrinkage-regrowth-shrinkage) of tumors has never previously been reported in the postoperative course, neither after microsurgery, nor after Gamma Knife surgery (GKS). We present the case of an adult with dorsal midbrain syndrome resulting from a pilocytic astrocytoma centered on the mesencephalic tectum. The tumor extended to the third ventricle and the thalamus. Initially, due to tumor growth, a biopsy was performed and histology established. Later, a ventriculocisternostomy for obstructive hydrocephalus was performed. Finally, GKS was performed, as the tumor continued to grow. After GKS, the lesion exhibited a biphasic response, with a major shrinkage at 3 months, regrowth within the target volume at 6 and 9 months and a second phase of important shrinkage at 12 months, which persisted for the next two years. The possible mechanisms for this particular response pattern are discussed.

Aqueductal Stenosis Has a New Dimension--Aspergillosis: A Rare Case Report and Review of the Literature.

BACKGROUND: Cerebral aspergillosis, often encountered in immunocompromised patients, is almost always fatal despite radical surgical and medical management and frequently is a finding at autopsy. Attempts at fungal isolation often are unsuccessful, and a high index of radiologic suspicion is necessary. CASE DESCRIPTION: A premature, 5-month-old female infant, born via normal vaginal delivery, presented with a progressive increase in head size since birth, delayed developmental milestones, and intermittent vomiting for 1 month. There was no history of trauma and no evidence of diabetes mellitus or hypertension, family history of tuberculosis, gestational diabetes, jaundice, or febrile eruptions. Neonatal jaundice was present after day 1, remained for 2 days, and was treated with phototherapy. Findings of the general and systemic examinations were unremarkable. Findings of a neurologic examination revealed a hypoactive infant with papilledema and extensor plantar bilaterally. Computed tomography scan of brain showed hydrocephalus attributable to aqueductal stenosis. On endoscopic third ventriculostomy, dense, friable, whitish yellow, nonvascular masses were encountered in the third ventricle, obstructing it. Her endoscopic third ventriculostomy success score was 10 + 0 + 10 = 20%. Histopathologic examination and culture revealed Aspergillus flavus. A week later, a medium-pressure ventriculoperitoneal shunt was done, and voriconazole was added. RESULTS: At discharge on the 7th postoperative day, 4 weeks and 12 weeks later (ie, first and second follow-up) the child was active, playful, and feeding normally. The first reported case of an aqueductal stenosis due to aspergillosis was in 2000 by van Landeghem FK et al. (Clin Neuropathol 19:26-29, 2000). To the best of our knowledge, this may only be the second reported case of hydrocephalus attributable to aqueductal stenosis caused by Aspergillosis. In conclusion, aspergillosis should not be ruled out as a differential diagnosis in aqueductal stenosis, even when the patient seems to be immunocompetent.

Cerebrospinal fluid reconstitution via a perfusion-based cadaveric model: feasibility study demonstrating surgical simulation of neuroendoscopic procedures.

Cadaveric surgical simulation carries the advantage of realistic anatomy and haptic feedback but has been historically difficult to model for intraventricular approaches given the need for active flow of CSF. This feasibility study was designed to simulate intraventricular neuroendoscopic approaches and techniques by reconstituting natural CSF flow in a cadaveric model. In 10 fresh human cadavers, a simple cervical laminectomy and dural opening were made, and a 12-gauge arterial catheter was introduced. Saline was continuously perfused at physiological CSF pressures to reconstitute the subarachnoid space and ventricles. A neuroendoscope was subsequently inserted via a standard right frontal bur hole. In 8 of the 10 cadavers, adequate reconstitution and endoscopic access of the lateral and third ventricles were achieved. In 2 cadavers, ventricular access was not feasible, perhaps because of a small ventricle size and/or deteriorated tissue quality. In all 8 cadavers with successful CSF flow reconstitution and endoscopic access, identifying the foramen of Monro was possible, as was performing septum pellucidotomy and endoscopic third ventriculostomy. Furthermore, navigation of the cerebral aqueduct, fourth ventricle, prepontine cistern, and suprasellar cistern via the lamina terminalis was possible, providing a complementary educational paradigm for resident education that cannot typically be performed in live surgery. Surgical simulation plays a critical and increasingly prominent role in surgical education, particularly for techniques with steep learning curves including intraventricular neuroendoscopic procedures. This novel model provides feasible and realistic surgical simulation of neuroendoscopic intraventricular procedures and approaches.

Hierarchical structure from motion optical flow algorithms to harvest three-dimensional features from two-dimensional neuro-endoscopic images.

Technical advances have led to an increase in the use of the endoscope in neurosurgery in recent years, particularly for intraventricular procedures and pituitary and anterior skull base surgery. Recently stereoscopic three-dimensional (3D) endoscopes have become available and may over time replace traditional two-dimensional (2D) imagery. An alternative strategy would be to use computer software algorithms to give monocular 2D endoscopes 3D capabilities. In this study our objective was to recover depth information from 2D endoscopic images using optical flow techniques. Digital images were recorded using a 2D endoscope and a hierarchical structure from motion algorithm was applied to the motion of the endoscope in order to calculate depth information for the generation of 3D anatomical structure. We demonstrate that 3D data can be recovered from 2D endoscopic images taken during endoventricular surgery where there is a mix of rapid camera motion and periods where the camera is nearly stationary. These algorithms may have the potential to give 3D visualization capabilities to 2D endoscopic hardware.

Onyx embolization of an avulsed thalamoperforator following endoscopic colloid cyst and lamina terminalis fenestration.

A patient presented with headaches and was found to have a colloid cyst in the third ventricle and ventriculomegaly. The patient underwent endoscopic colloid cyst resection and third ventriculostomy without incidence. Prior to emergence, a blown right pupil was acutely noted, and bright red blood emanated from the ventricular drain that was routinely placed in the endoscopy tract at the conclusion of the procedure. CTangiography demonstrated active extravasation from the pre-pontine cistern into the third ventricle and subarachnoid space. Emergency DSA confirmed active extravasation from an avulsed thalamoperforator arising from the proximal right P1 posterior cerebral artery, which was immediately embolized without incident.

[Treatment of child hydrocephalus by endoscopic third ventriculostomy in Senegal]. / Traitement de l'hydrocéphalie de l'enfant par ventriculocisternostomie endoscopique au Sénégal.

INTRODUCTION: Since its advent, endoscopic third ventriculostomy (ETV) has been an effective alternative to shunt placement for the treatment of hydrocephalus. The aim of this study was to report the results of our experience with this technique in children in Senegal. MATERIALS AND METHODS: This was a retrospective study of 70 cases of children aged between 5 months to 15 years who were treated by ETV in the Neurosurgery Department of Fann Hospital in Dakar, between January 2010 to December 2012. The results were evaluated based on the clinical criteria of Drake and the Canadian Pediatric Neurosurgery Study Group. The mean follow-up duration was 24 months (9-32 months). RESULTS: The mean age at diagnosis was 29 months. A male predominance (sex-ratio 1/3) was observed. We also noted a macrocephaly in 64.4 % of cases, psychomotor retardation in 40 % and decreased vision in 31.4 %. Headache and vomiting were found in 42.8 % and 61.4 % respectively. The main etiology was a stenosis of the mesencephalon aqueduct (30 %), followed by a Dandy-Walker malformation (25.7 %). Significant intraoperative bleeding was found in 2.8 % of patients. The most common postoperative complication was CSF leakage (18.6 %), followed by infections (14.2 %). The success rate according to the clinical criteria of Drake was 71.4 %. This success rate was influenced by the age of patients and the hydrocephalus etiology. No deaths occurred. CONCLUSION: The endoscopic third ventriculostomy is a simple, safe and effective technique. Its advantages in terms of quality of life and morbidity compared with bypass valves makes it the technique of choice, particularly in developing countries.

Onyx embolization of an avulsed thalamoperforator following endoscopic colloid cyst and lamina terminalis fenestration.

A patient presented with headaches and was found to have a colloid cyst in the third ventricle and ventriculomegaly. The patient underwent endoscopic colloid cyst resection and third ventriculostomy without incidence. Prior to emergence, a blown right pupil was acutely noted, and bright red blood emanated from the ventricular drain that was routinely placed in the endoscopy tract at the conclusion of the procedure. CTangiography demonstrated active extravasation from the pre-pontine cistern into the third ventricle and subarachnoid space. Emergency DSA confirmed active extravasation from an avulsed thalamoperforator arising from the proximal right P1 posterior cerebral artery, which was immediately embolized without incident.