Neuroendoscopy: one year of experience--personal results, observations and limits.

After reading reports of successful neuroendoscopic treatment of hydrocephalus, colloid cysts and arachnoid cysts as well as tumor biopsy, we started using endoscopic procedures in our Department, one year ago. One surgeon (E.S.) skilled in the Decq Endoscope, performed a series of sixteen procedures, from January 2001 to March 2002 (in patients aged 28 to 69 years). The most common pathology was obstructive hydrocephalus (14 cases), one was colloid cyst, and the last case was tumor biopsy. The surgical treatment consisted of third ventriculostomy, cyst opening and shrinking and tumor biopsy. In fourteen patients treated for hydrocephalus with third ventriculostomy (ETV), one required a definitive shunt. Complication occurred in one case with chronic subdural collection. We further report one case of aqueductal restoration after third ventriculostomy. Our results, with no neurological deficits or deaths, confirmed our opinion that neuroendoscopy is a safe surgical technique in well-selected patients and we believe it is the ideal treatment in obstructive hydrocephalus.     

Endoscopic third ventriculostomy for chronic hydrocephalus after tuberculous meningitis

BACKGROUND: Cerebrospinal fluid diversion procedures are indicated in patients with hydrocephalus after tuberculous meningitis (TBM). We present 2 patients with hydrocephalus after TBM who were successfully treated with endoscopic third ventriculostomy (ETV). METHODS: Two patients had been diagnosed with hydrocephalus after TBM and had undergone ventriculoperitoneal shunt surgery for the same. They presented with multiple episodes of shunt dysfunction. Endoscopic third ventriculostomy was performed (twice for one patient), and the patients were evaluated clinically and radiologically after the procedure. RESULTS: On long-term clinical follow-up (3 and 2 years, respectively), both patients were asymptomatic after the ETV. The first patient was radiologically evaluated 7 months after the procedure and the second patient 2 years after the procedure. The first patient showed a decrease in ventricular size. The second patient did not show any significant change in the ventricular size. CONCLUSION: Endoscopic third ventriculostomy can be considered as a safe and long-lasting solution for hydrocephalus after chronic TBM.     

Endoscopic third ventriculostomy for obstructive hydrocephalus

The indications for neuroendoscopy are not only constantly increasing, but even the currently accepted indications are constantly being adjusted and tailored. This is also true for one of the most frequently used neuroendoscopic procedures, the endoscopic 3rd ventriculostomy (ETV) for obstructive hydrocephalus. ETV has gained popularity and widespread acceptance during the past few years, but little attention has been paid to the techniques of the procedure. After a short introduction describing the history of ETV, an overview is given of all the different techniques that have been and still are employed to open the floor of the 3rd ventricle. The spectrum of indications for ETV has been widely enlarged over the last years. Initially, the use of this procedure was restricted to patients older than 2 years, to patients with an obvious triventricular hydrocephalus, and to those with a bulging, translucent floor of the 3rd ventricle. Nowadays, indications include all kinds of obstructive hydrocephalus but also communicating forms of hydrocephalus. The results of endoscopic procedures in treating these pathologies are given under special consideration of shunt technologies. In summary, from the review of the publications since the first ETV performed by Mixter in 1923, this technique is the treatment of choice for obstructive hydrocephalus caused by different etiologies and is an alternative to cerebrospinal fluid shunt application.Commentaries on this paper are available at and     

Endoscopic third ventriculostomy with ultrasonic contact microprobe.

The authors describe their first clinical experiences in endoscopic third ventriculostomy (ETV) with the original ultrasonic contact microprobe (UCM) designed at the Department of Neurosurgery in Zagreb. The analysis includes the clinical course of disease in eight patients submitted to surgery from May to September 1999 (3 men and 5 women, from 14 to 61 years of age). Surgery was performed in patients with neurological symptoms of elevated intracranial pressure and neuroradiological evidence of non-communicating hydrocephalus caused by mesencephalic aqueduct stenosis. The perforation in the base of the third brain ventricle made by the ultrasonic contact microprobe was widened by a balloon catheter. The authors have come to conclusion that the ETV when performed by contact ultrasonic microprobe is a small risk procedure in case of non-communicating hydrocephalus. For its small diameter (1.6 mm) and simple handling the newly designed contact ultrasonic microprobe is very suitable for use in neuroendoscopy as it enables fenestration of the third brain ventricle with minimal thermal and ultrastructural damage to the adjacent neurovascular structures. Further research will be focused on defining indications for the use of the device in other neuroendoscopic procedures as well.     

Management of hydrocephalus in pediatric patients with posterior fossa tumors: the role of endoscopic third ventriculostomy.

OBJECT: The authors undertook a study to evaluate the effectiveness of endoscopic third ventriculostomy in the management of hydrocephalus before and after surgical intervention for posterior fossa tumors in children. METHODS: Between October 1, 1993, and December 31, 1997, a total of 206 consecutive children with posterior fossa tumors underwent surgery at H?pital Necker-Enfants Malades in Paris. Excluded were 10 patients in whom shunts had been placed at the referring hospital. The medical records and neuroimaging studies of the remaining 196 patients were reviewed and categorized into three groups: Group A, 67 patients with hydrocephalus present on admission in whom endoscopic third ventriculostomy was performed prior to tumor removal; Group B, 82 patients with hydrocephalus who did not undergo preliminary third ventriculostomy but instead received conventional treatment; and Group C, 47 patients in whom no ventricular dilation was present on admission. There were no significant differences between patients in Group A or B with respect to the following variables: age at presentation, evidence of metastatic disease, extent of tumor resection, or follow-up duration. In patients in Group A, however, more severe hydrocephalus was demonstrated (p < 0.01): the patients in Group C were in this respect different from those in the other two groups. Ultimately, there were only four patients (6%) in Group A compared with 22 patients (26.8%) in Group B (p = 0.001) in whom progressive hydrocephalus required treatment following removal of the posterior fossa tumor. Sixteen patients (20%) in Group B underwent insertion of a ventriculoperitoneal shunt, which is similar to the incidence reported in the literature and significantly different from that demonstrated in Group A (p < 0.016). The other six patients (7.3%) were treated by endoscopic third ventriculostomy after tumor resection. In Group C, two patients (4.3%) with postoperative hydrocephalus underwent endoscopic third ventriculostomy. In three patients who required placement of CSF shunts several episodes of shunt malfunction occurred that were ultimately managed by endoscopic third ventriculostomy and definitive removal of the shunt. There were no deaths; however, there were four cases of transient morbidity associated with third ventriculostomy. CONCLUSIONS: Third ventriculostomy is feasible even in the presence of posterior fossa tumors (including brainstem tumors). When performed prior to posterior fossa surgery, it significantly reduces the incidence of postoperative hydrocephalus. The procedure provides a valid alternative to placement of a permanent shunt in cases in which hydrocephalus develops following posterior fossa surgery, and it may negate the need for the shunt in cases in which the shunt malfunctions. Furthermore, in patients in whom CSF has caused spread of the tumor at presentation, third ventriculostomy allows chemotherapy to be undertaken prior to tumor excision by controlling hydrocephalus. Although the authors acknowledge that the routine application of third ventriculostomy in selected patients results in a proportion of patients undergoing an "unnecessary" procedure, they believe that because patients' postoperative courses are less complicated and because the incidence of morbidity is low and the success rate is high in those patients with severe hydrocephalus that further investigation of this protocol is warranted.     

The role of neuroendoscopy in the management of brain tumours

Neuroendoscopy is increasingly used in the management of brain tumours and tumour related hydrocephalus and this study reviews the efficacy of neuroendoscopic interventions in this unit in patients with brain tumours. A series of 87 neuroendoscopic operations carried out in 77 patients with brain tumours over a 6-year period is reported. The age range of the patients was from 5 months to 70 years (median 13 years). In 56 cases (64%) presentation was with a newly-diagnosed tumour and hydrocephalus. The majority of the remaining patients had varying degrees of worsening hydrocephalus on the background of a previously diagnosed tumour. Neuroendoscopic third ventriculostomy (NTV) was successful in relieving hydrocephalus in the short term in 63/66 cases (95%) and in the longer term in 55/66 cases (83%). Neuroendoscopic tumour biopsies were successful in providing a tissue diagnosis in 17/28 cases (61%) and four extensive and three partial resections of tumour were carried out. There were two deaths within 30 days of the procedure with only one of these, secondary to intraventricular haemorrhage, directly related to neuroendoscopy. Few significant complications were noted otherwise. For selected intraventricular and paraventricular tumours neuroendoscopy offers the opportunity to combine relief of hydrocephalus with tumour biopsy and sampling of CSF in a single procedure.     

Endoscopic surgery for pineal region tumors.

Endoscopic surgery may play an important role in most patients with pineal region tumors. We report our experience with 5 patients treated by a burr hole endoscopic technique. The procedure included in all cases third ventriculostomy for the correction of hydrocephalus, CSF sample for cytology and tumor markers, and tumor biopsy for histological diagnosis. Endoscopic biopsies showed a pineocytoma in two cases, a germinoma in 2 and a low-grade astrocytoma in one. We agree that endoscopic surgery may allow us to select cases requiring a microsurgical approach (medium-sized or large non-germ-cell tumors) from cases to be treated only by irradiation and chemotherapy (germinomas and other non-germ-cell tumors). Then, in some patients with pineal region tumors the endoscopic procedure remains the only surgical treatment. When a direct microsurgical approach is indicated, it may be performed in a non-emergency situation and after correction of the hydrocephalus by endoscopic third ventriculostomy.     

Success of endoscopic third ventriculostomy in children less than 2 years of age

Current literature reveals different opinions about the effectiveness of endoscopic third ventriculostomy in the treatment of hydrocephalus in children less than 2 years of age. Performing a retrospective evaluation of our own experience in this age group, we aimed to contribute to the growing data on the controversial issues related to this procedure in children. In a series of 97 endoscopic third ventriculostomy procedures, 25 were performed in children less than 2 years of age as an initial treatment for hydrocephalus. A retrospective analysis of our data revealed that the overall success rate of endoscopic third ventriculostomy in this age group was 56%. However, analysis of the results in subgroups with different etiologies of hydrocephalus showed that the success rate of the procedure was 83% in patients with defined anatomic obstruction, 66.6% in post-hemorrhagic hydrocephalus, 50% in infection related hydrocephalus and 41.6% in hydrocephalus accompanied by myelomeningocele. This article considers our data and the features of endoscopic third ventriculostomy procedure in this age group, with a detailed review of the literature. In our experience, the success of endoscopic third ventriculostomy is etiology related rather than age-dependent. We suggest that there are no grounds for denying children younger than 2 years this chance for a shunt-free life.     

Clinical features in patients requiring reoperation after failed endoscopic procedures for hydrocephalus.

The aim of this study was to clarify the clinical features of patients at risk of secondary obstruction following endoscopic fenestration. Clinical notes and endoscopic findings for 15 patients treated with endoscopic procedures were retrospectively reviewed. Endoscopic third ventriculostomy (ETV) was performed as initial treatment in 4 patients with non-communicating hydrocephalus, including a neonate with myelomeningocele, and as an alternative to shunt revision in 4 patients. Two patients with non-communicating hydrocephalus caused by tumor or arachnoid cyst were also managed with third ventriculostomy. Four patients with loculated hydrocephalus underwent endoscopic septostomy. A child with an isolated fourth ventricle was treated with endoscopic aqueductoplasty. Of the 15 patients undergoing endoscopic procedure, 4 required reoperation. Of the 10 patients treated with ETV, only the neonate with myelomeningocele required a ventriculoperitoneal shunt because of failure of the initial procedure. Of the 4 patients treated with endoscopic septostomy, 2 children with loculated hydrocephalus following intraventricular hemorrhage (IVH) underwent a second septostomy. In a patient with an isolated fourth ventricle following posthemorrhagic hydrocephalus, recurrence was noted 8 months after the initial procedure. He underwent a second procedure using a stent implanted into the aqueduct to maintain CSF circulation. Sufficient stomal size or implantation of a stent may be required in the under-2-year age group with hydrocephalus accompanied by IVH and associated with myelomeningocele, in whom the risk of secondary obstruction may be high.     

The role of neuronavigation in intracranial endoscopic procedures

In occlusive hydrocephalus, cysts and some ventricular tumours, neuroendoscopy has replaced shunt operations and microsurgery. There is an ongoing discussion if neuronavigation should routinely accompany neuroendoscopy or if its use should be limited to selected cases. In this prospective clinical series, the role of neuronavigation during intracranial endoscopic procedures was investigated. In 126 consecutive endoscopic procedures (endoscopic third ventriculostomy, ETV, n?=?65; tumour biopsy/resection, n?=?36; non-tumourous cyst fenestration, n?=?23; abscess aspiration and hematoma removal, n?=?1 each), performed in 121 patients, neuronavigation was made available. After operation and videotape review, the surgeon had to categorize the role of neuronavigation: not beneficial; beneficial, but not essential; essential. Overall, neuronavigation was of value in more than 50% of the operations, but its value depended on the type of the procedure. Neuronavigation was beneficial, but not essential in 16 ETVs (24.6%), 19 tumour biopsies/resections (52.7%) and 14 cyst fenestrations (60.9%). Neuronavigation was essential in 1 ETV (2%), 11 tumour biopsies/resections (30.6%) and 8 cyst fenestrations (34.8%). Neuronavigation was not needed/not used in 48 ETVs (73.9%), 6 endoscopic tumour operations (16.7%) and 1 cyst fenestration (4.3%). For ETV, neuronavigation mostly is not required. In the majority of the remaining endoscopic procedures, however, neuronavigation is at least beneficial. This finding suggests integrating neuronavigation into the operative routine in endoscopic tumour operations and cyst fenestrations.     

Anesthetic management of surgical neuroendoscopies: usefulness of monitoring the pressure inside the neuroendoscope

Neuroendoscopic procedures are increasing in frequency in neurosurgical practice. We describe the anesthetic technique and the perioperative complications found in 100 neuroendoscopic interventions performed at our institution. Cranial tumor biopsy or retrieval (62%) and cisternostomy for hydrocephalus (33%) were the most frequent indications for neuroendoscopy. The mortality rate was low (1%). Intraoperative complications occurred in 36 patients, with arterial hypertension being the most frequent (53%). Postoperative complications occurred in 52 patients; anisocoria (31%) and delayed arousal (29%) were the most frequent. The pressure inside the endoscope was monitored intraoperatively in the last 47 patients. A saline-filled catheter from a pressure transducer connected to the neuroendoscopy system was used for pressure monitoring. We recorded the highest peak of pressure values measured during each procedure. Twenty-three patients (49%) had peak pressure values >30 mm Hg, 12 patients (25%) >50 mm Hg, and 3 patients >100 mm Hg. Only one patient had hemodynamic changes occurring simultaneously with the pressure changes. We found an association between pressure inside the endoscope >30 mm Hg and postoperative (P = .003) but not intraoperative complications. A relationship was found between surgical duration and postoperative complications (P = .002). Neither the pressure inside the endoscope or the intraoperative morbidity were related to surgical duration. We conclude that there may be a high rate of postoperative complications after neuroendoscopies, namely, new neurologic deficits. High pressure levels inside the endoscope during neuroendoscopic procedures can occur without hemodynamic warning signs. Pressure values >30 mm Hg are associated with postoperative morbidity, especially unexpected delayed recovery. Measuring the pressure inside the endoscope is technically easy and might be beneficial if performed in all neuroendoscopic procedures. Reducing the incidence of episodes of high peak pressure values might decrease the rate of postoperative complications.     

Endoscopic third ventriculostomy is the treatment of choice for obstructive hydrocephalus due to pediatric pineal tumors.

Pineal lesions in the pediatric patient are often complicated by the development of hydrocephalus due to obstruction of the aqueduct or the third ventricle by tumor masses. In such cases, hydrocephalus treatment has the highest priority and should be performed prior to any surgical treatment of the pineal tumor itself. The golden standard in obstructive hydrocephalus treatment remains placement of a temporary or permanent cerebrospinal fluid shunt, although there are many long-term complications associated with a shunt system. To avoid these and to render the patients independent from a failure-prone shunt system, we employed endoscopic third ventriculostomy for permanent relief of elevated intracranial pressure prior to surgical removal of the pineal lesions. The present study summarizes the results of this approach in 7 pediatric patients with obstructive hydrocephalus. No complications of the endoscopic procedure were encountered, and the ventriculostomy remained patent in all cases, as confirmed by motion sensitive MRI. The advantages of endoscopic third ventriculostomy as compared with other techniques are discussed, and its increasing role in the management of children with space occupying lesions of the pineal region is defined.     

Traumatic subependymal hematoma during endoscopic third ventriculostomy in a patient with a third ventricle tumor: case report.

Endoscopic third ventriculostomy has become a routine intervention for the treatment of non-communicating hydrocephalus. This technique is largely considered safe and a very low incidence of complications is reported. However, hemorrhage in the course of neuroendoscopy is still a problem difficult to manage. The authors present a case in which endoscopic third ventriculostomy and tumor biopsy were performed in a young patient with a huge tumor growing in the posterior part of the third ventricle. The surgical approach to realize the stoma was difficult because the tumor size reduced the third ventricle diameter. Surgical manipulation produced a traumatic subependymal hematoma. This hematoma drained spontaneously after few minutes into the ventricle and the blood was washed away. The postoperative neurological course was uneventful and the ventriculostomy showed to work well by reducing the size of the lateral ventricles and the intracranial pressure in three days. This complication during endoscopic third ventriculostomy has never been reported before. We emphasize the difficulty of endoscopic procedures in patients with huge tumors in the third ventricle. Where reduction in size of the third ventricle and of the foramen of Monro ist present we suggest a careful approach to the third ventricle.     

Mesencephalic ependymal cysts: treatment under pure endoscopic or endoscope-assisted keyhole conditions

OBJECT: Primary intracranial ependymal cysts are extremely rare. Similar to congenital intraparenchymal cysts in the mesencephalon they usually occur with symptoms of an occlusive hydrocephalus or symptoms like Parinaud syndrome, dizziness, or gait disturbance. The objective of this study was to evaluate the surgical methods for the treatment of these cysts and the clinical outcome of the patients. METHODS: The authors present the clinical records of 8 patients who were treated in their department for symptomatic mesencephalic ependymal cysts in the past 10 years. The patient age ranged from 22 to 60 years with a mean age of 44 years. In 4 cases the authors performed a suboccipital infratentorial supracerebellar approach by using endoscope-assisted microsurgery. The other 4 patients underwent a pure endoscopic procedure over a frontal bur hole trepanation. RESULTS: Four patients became symptom free, and the remaining 4 improved significantly after a mean follow-up duration of 38.5 months (range 5-119 months). One patient underwent 2 operations: first a ventriculocystostomy and 4 months later endoscopic third ventriculostomy because of recurrent hydrocephalus. In 1 case a second surgery was necessary because of a wound infection. In all of the patients an adequate fenestration of the cyst was achieved. CONCLUSIONS: A symptomatic mesencephalic ependymal cyst is an indication for neurosurgical intervention. These cysts can be treated successfully and most likely definitively by a pure endoscopic or endoscope-assisted keyhole neurosurgical technique. There were no morbid conditions or death due to the procedures in this group of 8 patients. Therefore, the authors regard these surgical procedures to be good alternatives to treatments such as shunt placement or stereotactic aspiration of the cysts.     

Failure of third ventriculostomy in the treatment of aqueductal stenosis in children

OBJECT: The goal of this study was to analyze the types of failure and long-term efficacy of third ventriculostomy in children. METHODS: The authors retrospectively analyzed clinical data obtained in 213 children affected by obstructive triventricular hydrocephalus who were treated by third ventriculostomy between 1973 and 1997. There were 120 boys and 93 girls. The causes of the hydrocephalus included: aqueductal stenosis in 126 cases; toxoplasmosis in 23 cases, pineal, mesencephalic, or tectal tumor in 42 cases; and other causes in 22 cases. In 94 cases, the procedure was performed using ventriculographic guidance (Group I) and in 119 cases by using endoscopic guidance (Group II). In 19 cases (12 in Group I and seven in Group II) failure was related to the surgical technique. Three deaths related to the technique were observed in Group I. For the remaining patients, Kaplan-Meier survival analysis showed a functioning third ventriculostomy rate of 72% at 6 years with a mean follow-up period of 45.5 months (range 4 days-17 years). No significant differences were found during long-term follow up between the two groups. In Group I, a significantly higher failure rate was seen in children younger than 6 months of age, but this difference was not observed in Group II. Thirty-eight patients required reoperation (21 in Group I and 17 in Group II) because of persistent or recurrent intracranial hypertension. In 29 patients shunt placement was necessary. In nine patients in whom there was radiologically confirmed obstruction of the stoma, the third ventriculostomy was repeated; this was successful in seven cases. Cine phase-contrast (PC) magnetic resonance (MR) imaging studies were performed in 15 patients in Group I at least 10 years after they had undergone third ventriculostomy (range 10-17 years, median 14.3 years); this confirmed long-term patency of the stoma in all cases. CONCLUSIONS: Third ventriculostomy effectively controls obstructive triventricular hydrocephalus in more than 70% of children and should be preferred to placement of extracranial cerebrospinal shunts in this group of patients. When performed using ventriculographic guidance, the technique has a higher mortality rate and a higher failure rate in children younger than 6 months of age and is, therefore, no longer preferred. When third ventriculostomy is performed using endoscopic guidance, the same long-term results are achieved in children younger than 6 months of age as in older children and, thus, patient age should no longer be considered as a contraindication to using the technique. Delayed failures are usually secondary to obstruction of the stoma and often can be managed by repeating the procedure. Midline sagittal T2-weighted MR imaging sequences combined with cine PC MR imaging flow measurements provide a reliable tool for diagnosis of aqueductal stenosis and for ascertaining the patency of the stoma during follow-up evaluation.     

First experiences with a 2.0-microm near infrared laser system for neuroendoscopy

Nd:YAG, argon and diode lasers have been used in neurosurgical procedures including neuroendoscopy. However, many neurosurgeons are reluctant to use these lasers because of their inappropriate wavelength and uncontrollable tissue interaction, which has the potential to cause serious complications. Recently, a 2.0-microm near infrared laser with adequate wavelength and minimal tissue penetration became available. This laser was developed for endoscopic neurosurgical procedures. It is the aim of the study to report the initial experiences with this laser in neuroendoscopic procedures. We have performed 43 laser-assisted neuroendoscopic procedures [multicompartmental congenital, posthaemorrhagic or postinfectious hydrocephalus (n = 17), tumour biopsies (n = 6), rescue of fixed and allocated ventricular catheters (n = 2), endoscopic third ventriculostomy (ETV, n = 17) and aqueductoplasty (n = 1)] in 41 patients aged between 3 months and 80 years. The laser beam was delivered through a 365-microm bare silica fibre introduced through the working channel of a rigid endoscope. It was used for the opening of cysts, perforating the third ventricular floor, and for coagulation prior to and after biopsy. The therapeutic goals [creating unhindered cerebrospinal fluid (CSF) flow between cysts, ventricles and cisterns, sufficient tissue samples for histopathological diagnosis and catheter rescue] were achieved in 40 patients by the first and in 2 patients by a second neuroendoscopic operation. In one child, a CSF shunt was later required despite patency of the created stoma proven by magnetic resonance imaging (MRI). In another patient ETV was abandoned due to a tiny third ventricle. There was neither mortality nor transient or permanent morbidity. The authors conclude that the use of the 2.0-microm near infrared laser enables safe and effective procedures in neuroendoscopy.     

Historical trends of neuroendoscopic surgical techniques in the treatment of hydrocephalus

The treatment of hydrocephalus nowadays is still a challenge for neurosurgery. Neuroendoscopy is a valuable alternative of the CSF shunts in hydrocephalus management. Because of the complicated and always changeable pathophysiology of hydrocephalus, the history of the endoscopic treatment of hydrocephalus is also a history of severe frustrations, great expectations, and significant achievements. The historical milestones and state of the art of neuroendoscopic treatment of hydrocephalus are reviewed for each of its surgical techniques: choroid plexus coagulation, third ventriculostomy, aqueductoplasty, septostomy, foraminal plasty of the foramen of Monro, and foraminal plasty of the foramen of Magendie. The future trends of neuroendoscopic treatment of hydrocephalus such as robotics, image-guided neuroendoscopic surgical techniques, treatment "in utero", application of stem cell therapy, implementation of new technological solutions, and so on are discussed in the light of the approaching end of the century of neuroendoscopy.     

Stereotactic third ventriculostomy in patients with nontumoral adolescent/adult onset aqueductal stenosis and symptomatic hydrocephalus

Sixteen consecutive patients with obstructive hydrocephalus due to nontumoral aqueductal stenosis of adolescent or adult onset underwent computerized tomography-guided stereotactic third ventriculostomy. Computer-assisted angiographic target-point cross-registration was used in surgical planning to reduce morbidity. The procedure was used as primary treatment in five previously unshunted patients and in 11 patients who had previously received shunts and who presented when their shunts became obstructed (five patients), became infected (five patients), or required multiple revisions (one patient). At the time of third ventriculostomy, shunt hardware was removed in patients with infected shunts and the distal element of the shunt was ligated in all patients with obstructed shunts except one, who later required repeat third ventriculostomy; the distal shunt was ligated at that time. Follow-up data (range 1 to 5 years, mean 3 1/2 years, after surgery) showed that only one of the 16 patients had undergone a shunting procedure after the third ventriculostomy. The other 15 patients are asymptomatic and shunt-independent. In previously shunt-dependent patients, the peripheral subarachnoid space and cerebrospinal fluid absorption mechanism remained patent in spite of shunts placed earlier. Therefore, in patients with obstructive hydrocephalus due to aqueductal stenosis of adolescent or adult onset, stereotactic third ventriculostomy should be seriously considered as primary surgical management in previously unshunted patients and in shunt-dependent patients with obstructed or infected shunts.     

Neuroendoscopic biopsy for intraventricular tumors.

Neuroendoscopy has been shown to be an effective and minimally invasive method in the management of intraventricular tumors. Endoscopic tumor biopsy with or without additional endoscopic procedures such as third ventriculostomy and septostomy can be performed at the same session. Neuroendoscopic tumor biopsy was performed in 18 patients in our department. Their ages ranged from 2 to 65 years (median 12 years); only two of them were adult. Location of the tumors were as follows: pineal region in 7, hypothalamus and 3rd ventricle in 4, lateral ventricle in 4, thalamus in 2, and tectal in 1 patient. All procedures were performed under general anesthesia using rigid neuroendoscopes. Cerebrospinal fluid (CSF) was collected at the beginning of the procedure for cytological analysis and for pineal tumor markers. Biopsy forceps were used to obtain tissue from the lesion. The third ventriculostomy was performed in all patients with a pineal tumor, in addition to the tumor biopsy. The pathological examinations revealed a low-grade astrocytoma in 6 patients, anaplastic astrocytoma in 3, germinoma in 3, pineocytoma in 1, pineoblastoma in 2, glioblastoma multiforme in 1 and granulomatous lesion in 1. Subsequent mode of treatment such as radiation therapy, chemotherapy or radical surgery was determined on the basis of pathological diagnosis. Neuroendoscopic tumor biopsy is a less invasive method than open surgery and has some advantages such as treating the hydrocephalus at the same surgical session and the availability of CSF cytology. Neuroendoscopic techniques should be considered in selected patients.