Small-ventricle neuroendoscopy for pediatric brain tumor management

Intraventricular Tumors: Surgical Considerations in Lateral and Third Ventricular Tumors

Management of lateral and third ventricular tumors has been a challenge for neurosurgeons. Advances in imaging and pathology have helped in a better understanding of the treatment options. Technical refinement of microsurgical technique and addition of endoscopy has enabled more radical excision of tumors, when indicated, and added more safety.A proper understanding of the pathology at various ages and treatment options is continuously evolving. Many pediatric tumors are amenable to conservative surgical methods with effective complementary treatments. However, radical surgery is required in many adults as the main treatment and for many benign tumors. Various intraventricular lesions encountered and their surgical management is reviewed here for their efficacy, safety, and outcome, encompassing changes in our practice over the last 20 years.

Using robotics to move a neurosurgeon's hands to the tip of their endoscope

A major advantage of surgical robots is that they can reduce the invasiveness of a procedure by enabling the clinician to manipulate tools as they would in open surgery but through small incisions in the body. Neurosurgery has yet to benefit from this advantage. Although clinical robots are available for the least invasive neurosurgical procedures, such as guiding electrode insertion, the most invasive brain surgeries, such as tumor resection, are still performed as open manual procedures. To investigate whether robotics could reduce the invasiveness of major brain surgeries while still providing the manipulation capabilities of open surgery, we created a two-armed joystick-controlled endoscopic robot. To evaluate the efficacy of this robot, we developed a set of neurosurgical skill tasks patterned after the steps of brain tumor resection. We also created a patient-derived brain model for pineal tumors, which are located in the center of the brain and are normally removed by open surgery. In comparison, testing with existing manual endoscopic instrumentation, we found that the robot provided access to a much larger working volume at the trocar tip and enabled bimanual tasks without compression of brain tissue adjacent to the trocar. Furthermore, many tasks could be completed faster with the robot. These results suggest that robotics has the potential to substantially reduce the invasiveness of brain surgery by enabling certain procedures currently performed as open surgery to be converted to endoscopic interventions.

Endoscopic transventricular biopsy in brainstem diffuse midline glioma: how I do it

BACKGROUND

Brainstem diffuse midline gliomas represent infiltrative and rare pediatric tumors with a dismal prognosis. Surgical biopsy is emerging as a valid technique to define diagnosis and molecular markers for future targeted therapies.

METHOD

We describe the key steps of an endoscopic trans-ventricular biopsy of a brainstem diffuse midline glioma and associated ventriculomegaly. The relevant surgical anatomy along with an illustrative video is described.

CONCLUSION

The endoscopic third ventriculostomy combined with a punch biopsy of a brainstem diffuse midline glioma associated with ventriculomegaly represent a feasible and low-risk procedure to simultaneously treat incipient hydrocephalus and molecular diagnosis for future treatment and research.

Endoscopic third ventriculostomy in previously shunt-treated patients

OBJECTIVE

Endoscopic third ventriculostomy (ETV) is an option for treatment of hydrocephalus, including for patients who have a history of previous treatment with CSF shunt insertion. The purpose of this study was to report the success of postshunt ETV by using data from a multicenter prospective registry.

METHODS

Prospectively collected data in the Hydrocephalus Clinical Research Network (HCRN) Core Data Project (i.e., HCRN Registry) were reviewed. Children who underwent ETV between 2008 and 2019 and had a history of previous treatment with a CSF shunt were included. A Kaplan-Meier survival curve was created for the primary outcome: time from postshunt ETV to subsequent CSF shunt placement or revision. Univariable Cox proportional hazards models were created to evaluate for an association between clinical and demographic variables and subsequent shunt surgery. Postshunt ETV complications were also identified and categorized.

RESULTS

A total of 203 children were included: 57% male and 43% female; 74% White, 23% Black, and 4% other race. The most common hydrocephalus etiologies were postintraventricular hemorrhage secondary to prematurity (56, 28%) and aqueductal stenosis (42, 21%). The ETV Success Score ranged from 10 to 80. The median patient age was 4.1 years. The overall success of postshunt ETV at 6 months was 41%. Only the surgeon's report of a clear view of the basilar artery was associated with a lower likelihood of postshunt ETV failure (HR 0.43, 95% CI 0.23-0.82, p = 0.009). None of the following variables were associated with postshunt ETV success: age at the time of postshunt ETV, etiology of hydrocephalus, sex, race, ventricle size, number of previous shunt operations, ETV performed at time of shunt infection, and use of external ventricular drainage. Overall, complications were reported in 22% of patients, with CSF leak (8.6%) being the most common complication.

CONCLUSIONS

Postshunt ETV was successful in treating hydrocephalus, without subsequent need for a CSF shunt, in 41% of patients, with a clear view of the basilar artery being the only variable significantly associated with success. Complications occurred in 22% of patients. ETV is an option for treatment of hydrocephalus in children who have previously undergone shunt placement, but with a lower than expected likelihood of success.

Combined Neuroendoscopic Techniques in the Management of Pediatric Brain and Skull Base Tumors: A Single-Institutional Case Series

BACKGROUND

Central nervous system tumors encompass the leading cause of cancer-related death in the pediatric population. Neuroendoscopic techniques have been optimized over the years, becoming an important tool for the management of brain tumors. Our study aims to review the indications for neuroendoscopic procedures and the feasibility of combined interventions.

METHODS

This is a single-center, self-adjudicated, retrospective experience. Inclusion criteria consisted of pediatric patients (≤18 years old) who underwent management of brain tumor or related diseases with the employment of neuroendoscopy.

RESULTS

A total of 47 patients undergoing 51 procedures met inclusion criteria. The mean age was 9.8 ± 4.6 years, and the majority were female (55.3%). Common indications for endoscopic intervention were hydrocephalus management (n = 24; 16 endoscopic third ventriculostomies and 9 septostomies), tumor biopsy (n = 19), cyst fenestration (n = 16), and tumor resection (n = 9). In one third of the cases, combined interventions occurred during a single operative session. Hydrocephalus was successfully managed in 74.4% of cases; tumor biopsy confirmed the diagnosis in 95.8% of cases, and gross total resection was achieved in 88.9% of cases. Cyst fenestration required reintervention in 3 cases: one case associated with initial cyst enlargement and 2 cases with the development of new tumor cysts separated from the originally fenestrated cyst. The overall complication rate was 6.3%, with only one major safety event, which was successfully managed.

CONCLUSIONS

Neuroendoscopy is an important minimally invasive tool for diagnosing and treating pediatric patients with brain tumors, permitting to address multiple problems in a single surgery.

Role of endoscopic surgical biopsy in diagnoses of intraventricular/periventricular tumors: review of literature including a monocentric case series

The intra- and periventricular location tumor (IPVT) of a brain remains a hard challenge for the neurosurgeon because of the deep location and eloquent anatomic associations. Due to this high risk of iatrogenic injury, many surgeons elect to perform biopsies of such lesions to establish a diagnosis. On the one hand, stereotaxic needle biopsy (SNB) is a minimally invasive procedure but with a significant risk of complications and a high risk of lack of tissue for molecular analyses for this region [Fukushima in Neurosurgery 2:110-113 (1978)]; on the other hand, the use of endoscopic intraventricular biopsy (EIB) allows for diagnosis with minimal surgical intervention [Iwamoto et al. in Ann Neurol 64(suppl. 6):628-634 (2008)]. IPVTs and related CSF pathway obstructions can be safely and effectively treated with endoscopic techniques. It is not possible to compare EIB with diagnoses made by any other method or with the established treatment. We aim to analyze the accuracy of EIB results by comparing them with results of biopsies performed later, in other methods and thereby evaluating the treatment evolution considering our personal experience. The difficulties and complications encountered are presented and compared with those reported in the literature to obtain the best review possible for this topic. A systematic review of literature was done using MEDLINE, the NIH Library, PubMed, and Google Scholar yielded 1.951 cases for EIB and 1912 for SNB, according to standard systemic review techniques. Review was conducted on 50 studies describing surgical procedures for lesions intra- and para-ventricular. The primary outcome measure was a diagnostic success. We also consider 20 patients with IPVT treated in our department. Clinical characteristics and surgical outcome were evaluated and a systematic review of the literature was performed. Overall, all our biopsies were diagnostic, with a positive histologic sample in 100% of our patients. 8 patients underwent a concurrent endoscopic third ventriculostomy. 4 patients underwent a concurrent ventriculostomy combined with septostomy. For 1 patient was necessary the only septostomy combined with biopsy. Every case has obtained a histological diagnosis. The percentage of complications was very low with only 1 case of post-operative infection and 1 case of hemorrhage. It was impossible to create a specific comparison from literature data of IPVTs between a stereotactic and endoscopic procedure, it presents only the collection of pineal gland tumor [Kelly in Neurosurgery 25(02):185-194 (1989); Quick-Weller in World Neurosurgery 96:124-128 (2016)] or unknown location of the lesion in major review [Marenco-Hillembrand et al. in Front Oncol 8:558 (2018)]. The present study aims to report our experience with the surgical management of IPVTs. The EIB sample yields an accurate histologic diagnosis tumor, with a positive histologic sample in 87, 95% of patients. The choice of the appropriate procedure should consider not only the preference and the experience of the neurosurgeon but also the several other variables as the location. While some periventricular lesions are better approached by endoscopic techniques, others are more suited for stereotactic-guided approaches. The ability to perform an EIB and relieve tumor-associated hydrocephalus by neuroendoscopy is considered to be a benefit of this procedure since this is less invasive than other treatments.

Neuroendoscopic Surgery versus Craniotomy for Supratentorial Hypertensive Intracerebral Hemorrhage: A Systematic Review and Meta-Analysis

BACKGROUND

No consensus has been achieved on the superiority between neuroendoscopy (NE) and craniotomy (CT) for the treatment of supratentorial hypertensive intracerebral hemorrhage (HICH). The purpose of this study is to analyze the efficacy and safety of NE versus CT for supratentorial HICH.

METHODS

A systematic search of English databases (PubMed, Embase, the Cochrane Library, and Web of Science) was performed to identify related studies reported from September 1994 to June 2019. The Newcastle-Ottawa Scale and the Cochrane Reviewer's Handbook 5.0.0 were separately used to evaluate the quality of the included observational studies and randomized controlled trials. RevMan 5.3 software was adopted to conduct the meta-analysis. The outcome measures included the primary and secondary outcomes. Subgroup analysis was performed to explore the impact of year of publication, initial Glasgow Coma Scale (GCS) score, age, time to surgery, hematoma volume, and surgical methods on the outcome measures.

RESULTS

Fifteen studies (3 randomized controlled trials and 12 observational studies), comprising 1859 patients with supratentorial HICH, were included in this meta-analysis. The pooled results showed that NE could increase the good functional outcome (GFO) (P < 0.0003) and hematoma evacuation rate (P = 0.0007) and reduce the mortality (P < 0.00001), blood loss (P = 0.004), operation time (P < 0.00001), hospital stays (P = 0.006), and intensive care unit stays (P < 0.0001) compared with CT. In addition, NE could also have a positive effect on preventing postoperative infection (P < 0.00001) and total complications (P < 0.00001). However, in postoperative rebleeding incidence (P = 0.12), no obvious difference was found between the 2 groups. Publication bias was low regarding GFO, mortality, and hematoma evacuation rate. Subgroup analysis suggested that year of publication, initial GCS score, age, hematoma volume, and surgical methods did not affect the hematoma evacuation rate significantly. The difference in mortality was not statistically significant in the subgroup of hematoma volume <50 mL (P = 0.44) and initial GCS score >8 (P = 0.09). In addition, the data suggested that time to surgery and surgical methods might be the important factors affecting GFO and mortality.

CONCLUSIONS

NE might be a safer and more effective surgical method than CT in the treatment of patients with supratentorial HICH. However, because of the existence of some limitations, the safety and validity of NE were weakened. More high-quality trials should be included to verify our conclusion.

Third Ventricular Tumors: A Comprehensive Literature Review

Third ventricle tumors are uncommon and account for 0.6 - 0.9% of all the brain tumors. Tumors of the third ventricle are classified into primary tumors, such as colloid cysts, choroid plexus papillomas, and ependymomas, or secondary tumors, such as craniopharyngiomas, optic nerve gliomas, pineal tumors, and meningiomas. Third ventricular tumors are uncommon, and their treatment involves significant morbidity and mortality. The colloid cyst has a better surgical outcome and many approaches are available to achieve a complete cure. Choroid plexus papilloma is also a common tumor documented with its treatment majorly based on surgical resection. In addition to multiple treatment options for craniopharyngiomas, surgery is the most preferred treatment option. Ependymomas also have few treatment options, with surgical resection adopted as the first line of treatment.

Neuroendoscopy via an Extremely Narrow Foramen of Monro: A Case Report

Herein, safe and reliable neuroendoscopic biopsy via an extremely narrow foramen of Monro (ENFM) for a non-hydrocephalic patient with hypothalamic and pineal region tumors was successfully applied. A 17-year-old boy presented with hypothalamic manifestations attributed to hypothalamic and pineal region tumors. Small ventricles were seen. Intraoperatively, to advance different diameter steerable fiberscopes via ENFM, the third ventricle was flushed to induce a moment increase in the intraventricular pressure with subsequent dilatation of FM. Postoperative course was uneventful. Histopathological studies revealed a yolk sac tumor. Adjuvant therapy was applied. Follow-up neuroimaging disclosed marvellous improvement of the condition. His symptoms gradually improved.

Neuroendoscopic Intraventricular Biopsy in Children with Small Ventricles Using Frameless VarioGuide System

Endoscopic biopsy for intraventricular tumors in pediatric patients with small ventricles is a challenging procedure because of the risk of morbidity during the intraventricular approach. We describe the use of the VarioGuide system for intraventricular endoscopic biopsy in 9 consecutive pediatric patients with intraventricular lesions and small ventricular size. All patients had lesions in the anterior part of the third ventricle with a median frontal and occipital horn ratio of 0.33. Patients presented with growth failure (n = 4), visual disturbances (n = 4), and seizures (n = 1). The VarioGuide system consists of an ergonomic arm with 3 joints for gross adjustment. The 3 rotational joints on the distal side of the system are adjusted according to the angles of the planned trajectory. The endoscope is adjusted to the distal side of the VarioGuide and inserted through the ring, previously set for the diameter of the endoscope and for the planned trajectory. The accuracy of the trajectory and correct ventricular cannulation are confirmed under endoscopic guidance. The biopsy is carried out according to the standard technique. In all cases, the biopsy sample provided the definitive diagnosis. Diagnoses included germinomas in 4 patients, hamartoma in 1 patient, hypothalamic astrocytoma in 2 patients, and craniopharyngioma in 2 patients. The use of the VarioGuide system for intraventricular endoscopic biopsy is highly recommended for pediatric patients with small ventricle size. This technique may help minimize the risk of unnecessary brain damage during the entrance to small ventricles.

Resection of Intraventricular Tumors in Children by Purely Endoscopic Means

OBJECTIVE

Neuroendoscopy is increasingly being used in the management of intraventricular brain tumors. The role of endoscopy in diagnostic biopsy is well established. Expansion of these techniques may allow for definitive resection of intraventricular tumors. We report the feasibility and outcomes of endoscopic resection of select intraventricular tumors in children.

METHODS

The clinical characteristics of 11 children with solid intraventricular tumors who underwent tumor resection were reviewed. Twelve procedures were performed.

RESULTS

Gross-total resection was achieved in 11 of 12 cases (92%). Maximal tumor diameter ranged from 9 to 26 mm (mean, 16.6 mm). Pathologic results included subependymal giant cell astrocytomas, ependymomas, nongerminomatous germ cell tumors, and pilocytic astrocytomas. Mean follow-up was 35 months (range, 10-109 months). All patients returned to their neurologic baselines after surgery. Local tumor recurrence occurred in 1 patient and distant recurrence in another. In 1 patient, a transitory intraoperative increase of intracranial pressure without clinical implications occurred. There was no permanent morbidity or mortality in this series. Hydrocephalus was present preoperatively in 5 cases and was treated either with tumor removal alone or with an additional endoscopic third ventriculostomy. No patient required a ventriculoperitoneal shunt.

CONCLUSIONS

Neuroendoscopic gross-total resection of solid intraventricular tumors is a safe and efficacious procedure in carefully selected pediatric patients.

Endoscopic Surgery in Nonhydrocephalous Third Ventricular Colloid Cysts: A Feasibility Study

BACKGROUND

The aim of this study was to investigate the feasibility and effectiveness of endoscopic neurosurgery for patients with third ventricular colloid cysts but without ventriculomegaly.

METHODS

Seventy-one patients with third ventricular colloid cysts were identified and recruited to this study. Eighteen of these patients did not have concomitant hydrocephalus and underwent primary endoscopic surgery for cyst resection. The surgical technique, the success rate, and patients' outcome were assessed and compared with another 53 patients with hydrocephalus who underwent similar procedures. Our study was performed in a retrospective basis, although in middle of our work we decided to study and follow nonhydrocephalus cases prospectively.

RESULTS

The ventricular compartments were successfully cannulated and gross total resection and near total resection of the colloid cysts was achieved in all patients. There were no persistent operative complications related to the endoscopic procedure. The success rate for endoscopic surgery in patients without hydrocephalus was similar to its value in patients with hydrocephalus.

CONCLUSIONS

Endoscopic resection of third ventricular colloid cyst in patients without hydrocephalus seems to be feasible, effective, and not contraindicated.

Endoscopic biopsy of brain tumors: Does the technique matter?

Background:

Endoscopic biopsy of brain tumors is an important part of the armamentarium of management of intra- and periventricular tumors that is generally considered an acceptable and, in some situations, a preferred method for tissue sampling. The diagnostic yield of the procedure has been variably reported. Technical aspects of the procedure should undoubtedly reflect on its success rate and accuracy. Such impact on diagnostic yield of endoscopic brain biopsy is infrequently discussed in the literature.

Methods:

A search of the medical literature was conducted for publications on endoscopic brain biopsy. These reports were analyzed regarding the various technical aspects.

Results:

In the 43 publications analyzed, lenscopes were exclusively used in 22 reports and a tissue diagnosis was possible in 362 out of 387 endoscopic biopsies with a diagnostic yield of 93.54%. Only fiberscopes were used in 8 reports and a tissue diagnosis was possible in 100 out of 132 endoscopic biopsies with a diagnostic yield of 75.76%. The diagnostic yield in the mixed and unspecified groups was 88.95 and 88.04%, respectively. Very few details on the histopathological methods and tumor molecular genetics could be found.

Conclusion:

Endoscopic biopsy of brain tumors has a higher diagnostic yield when lenscopes are used. Neuronavigation seems to add to the diagnostic accuracy of the procedure. Studies detailing molecular genetic features of biopsied tumors are necessary in the future.

Flexible endoscopy for management of intraventricular brain tumors in patients with small ventricles

OBJECT

Endoscopic surgery is generally withheld in patients with small ventricles due to difficulties in ventricular cannulation and intraventricular manipulation. The effectiveness of flexible endoscopy for management of intraventricular brain tumors in patients with small ventricles was evaluated.

METHODS

Forty-five patients who underwent endoscopic surgery with a flexible endoscope for intraventricular brain tumors were divided into small-ventricle and ventriculomegaly groups according to the frontal and occipital horn ratio (FOR). Retrospective review of these cases was performed and achievement of surgical goals and morbidity were assessed.

RESULTS

Among the 45 patients, there were 14 with small ventricles and 31 with ventriculomegaly. In the smallventricle group, targeted tumors were located in the suprasellar region in 12 patients and in the pineal region in 2. In the ventriculomegaly group, tumors were located in the pineal region in 15 patients, in the suprasellar region in 9, in the lateral ventricle in 4, in the midbrain in 2, and in the fourth ventricle in 1. In the small-ventricle group, ventricular cannulation was successful and the surgical goals were accomplished in all patients. In ventriculomegaly group, sampling of the tumor was not diagnostic due to intraoperative hemorrhage in 1 patient. There were no significant differences in the rate of achieving the surgical goals or the morbidity between the 2 groups.

CONCLUSIONS

Endoscopic surgery using a flexible endoscope is useful for management of intraventricular brain tumors in patients with small ventricles. A flexible endoscope allows excellent maneuverability in introducing the device into the lateral ventricle and manipulating through small ventricles.

Neuroendoscopic biopsy of pediatric brain tumors with small ventricle

PURPOSE

Intraventricular endoscopic procedures to resect or biopsy peri- or intraventricular tumors may have not been used in patients with small ventricles due to the presumed difficulties with ventricular cannulation and the perceived risk of morbidity. The purpose of this study is to review the feasibility and safety of neuroendoscopic procedures in the biopsy of pediatric brain tumors with a small ventricle.

METHODS

Between January 2006 and January 2013, 72 children were identified with brain tumors confirmed by transventricular endoscopic biopsy. Patients were divided into non-hydrocephalus and hydrocephalus groups, and the ratio of the two groups was 20:52.

RESULTS

In 20 pediatric brain tumors with small ventricle, the targeted lesion was successfully approached under the guidance of neuronavigation. Navigational tracking was especially helpful in entering small ventricles and in approaching the third ventricle through the narrow foramen of Monro. The histopathologic diagnosis was established in all 20 patients: nine germinomas, three mixed germ cell tumors, two pilomyxoid astrocytomas, and two pilocytic astrocytomas. The tumor biopsy sites were the suprasellar area (n = 10), pineal area (n = 4), lateral ventricular wall (n = 4), and mammillary body (n = 1). There were no major morbidities related to the endoscopic procedure.

CONCLUSION

Neuroendoscopic biopsy or resection of peri- or intraventricular tumors in pediatric patients without hydrocephalus is feasible. Navigation-guided neuroendoscopic procedures improved the accuracy of the neuroendoscopic approach and minimized brain trauma. The absence of ventriculomegaly in patients with brain tumor may not serve as a contraindication to neuroendoscopic tumor biopsy.

Neuroendoscopic resection of intraventricular tumors: a systematic outcomes analysis

Introduction. Though traditional microsurgical techniques are the gold standard for intraventricular tumor resection, the morbidity and invasiveness of microsurgical approaches to the ventricular system have galvanized interest in neuroendoscopic resection. We present a systematic review of the literature to provide a better understanding of the virtues and limitations of endoscopic tumor resection. Materials and Methods. 40 articles describing 668 endoscopic tumor resections were selected from the Pubmed database and reviewed. Results. Complete or near-complete resection was achieved in 75.0% of the patients. 9.9% of resected tumors recurred during the follow-up period, and procedure-related complications occurred in 20.8% of the procedures. Tumor size ≤ 2cm (P = 0.00146), the presence of a cystic tumor component (P < 0.0001), and the use of navigation or stereotactic tools during the procedure (P = 0.0003) were each independently associated with a greater likelihood of complete or near-complete tumor resection. Additionally, the complication rate was significantly higher for noncystic masses than for cystic ones (P < 0.0001). Discussion. Neuroendoscopic outcomes for intraventricular tumor resection are significantly better when performed on small, cystic tumors and when neural navigation or stereotaxy is used. Conclusion. Neuroendoscopic resection appears to be a safe and reliable treatment option for patients with intraventricular tumors of a particular morphology.

Safety and diagnostic accuracy of neuroendoscopic biopsies: an international multicenter study

OBJECT

Analysis of the safety and morbidity of neuroendoscopic biopsies (NEBs), as well as the reliability in obtaining an accurate diagnosis, has until now been based on studies with relatively small sample sizes. Through the cooperative efforts of several international medical centers, authors of the present study collected data on a large number of patients to obtain better insight into this issue. When possible, they compared pathology obtained through an NEB with the "gold-standard" pathology obtained in open surgery.

METHODS

Thirteen randomly chosen medical centers in 9 countries collected data for patients who had undergone NEB, which were then analyzed for universal complications, bleeding, navigation technique, pathology, mismatch between biopsy results and final diagnosis, and a number of other potentially influential factors.

RESULTS

Data for 293 patients were analyzed. Sixty percent of the patients were male, and patient ages ranged from 0.1 to 78.7 years (median age 20.4 years). The most common tumor locations were pineal (33.1%), thalamic (16.7%), tectal (13%), and hypothalamic (4.4%). Fifty percent of the tumors were larger than 20 mm, 36% were between 10 and 20 mm, and 14% were smaller than 10 mm. Intraoperative bleeding was seen in 275 patients (94%). The amount of blood was noted as mild in 75%, moderate in 13%, and severe in 6%. Infection occurred in 8 patients (3%). Death occurred in 1 patient (0.3%), which was caused by severe intraoperative bleeding. Biopsies were informative in 265 patients (90.4%). Seventy-eight patients (26.6%) had open surgery following the NEB. For these patients, the pathology results from the NEB were compared with those from the open surgery that followed. In 14 cases (17.9%) there was disagreement on the pathology. Of these cases, a meaningful mismatch, in which the erroneous NEB pathology could have led to an inappropriate management decision, occurred in 9 cases (11.5%). Most of these meaningful mismatches were lesions diagnosed as low-grade or pilocytic astrocytoma on the NEB and later proved to be high-grade astrocytoma (4 cases) and 1 case each of meningioma, cavernoma, primitive neuroectodermal tumor, neurocysticercosis, and pineocytoma.

CONCLUSIONS

In experienced hands, NEBs can be performed with low morbidity and mortality, providing meaningful pathological data for the majority of patients with a wide range of tumor types, locations, and presentations. These biopsies also offer other advantages, such as the ability to perform concomitant endoscopic third ventriculostomy and septum pellucidotomy. However, due caution must be maintained, since pathology obtained from an NEB, as with stereotactic biopsies, may be subject to sampling errors, especially when the results seem to indicate a low-grade glial tumor.

Endoscopic Colloid Cyst Resection in the Absence of Ventriculomegaly

BACKGROUND:

The absence of ventriculomegaly has been considered an overt or relative contraindication to the endoscopic resection of colloid cysts. In the past, endoscopic removal of colloid cysts in the absence of ventriculomegaly has been considered ill advised. Reports of successful endoscopic surgery in small ventricles are surfacing.

OBJECTIVE:

We examined the combined experience of 2 high-volume endoscopic centers to characterize the outcomes of patients undergoing endoscopic removal of colloid cysts in small ventricles.

METHODS:

We retrospectively reviewed all endoscopic colloid cyst removal procedures by the 2 senior authors (P.N., C.T.) performed at the Barrow Neurological Institute over an 8-year period. Radiographic, clinical, and interview data were recorded and analyzed. The age-adjusted relative bicaudate index was used to define small ventricles.

RESULTS:

Sixteen patients (8 female) underwent attempted endoscopic removal of a colloid cyst in the absence of ventriculomegaly. Surgery was technically successful in 15 patients. The cyst was removed completely in 13 of patients. Short-term memory loss was initially present in 3 patients and completely resolved in all but 1 patient who had presented with short-term memory loss. Temporary complications occurred in 2 patients.

CONCLUSION:

Normal-size ventricles are not a contraindication to endoscopic removal of third ventricular colloid cysts. Complication rates are at least comparable to those of patients with ventriculomegaly or to those undergoing open microsurgical resection.

Pediatric considerations for pineal tumor management

Pineal tumors are relatively rare central nervous system lesions with a predilection for the pediatric population. For the vast majority of these lesions, surgical resection is a critical step in effective treatment. This article discusses current strategies for preoperative evaluation, operative management, and postoperative care of the pediatric patient with a newly diagnosed pineal region tumor.

Evaluating the Children's Hospital of Alabama endoscopic third ventriculostomy experience using the Endoscopic Third Ventriculostomy Success Score: an external validation study

OBJECT

Endoscopic third ventriculostomy (ETV) success is dependent on patient characteristics including age, origin of hydrocephalus, and history of shunt therapy. Using these factors, an Endoscopic Third Ventriculostomy Success Score (ETVSS) model was constructed to predict success of therapy. This study reports a single-institution experience with ETV and explores the ETVSS model validity.

METHODS

A retrospective chart review identified 151 consecutive patients who underwent ETV at a pediatric hospital between August 1995 and December 2009. Of these 151, 136 patients had at least 6 months of clinical follow-up. Data concerning patient characteristics, operative characteristics, radiological findings, complications, and success of ETV were collected. The actual success rates were compared with those predicted by the ETVSS model.

RESULTS

The actual success rate of ETV at 6 months was 68.4% (93 of 136 patients), which compared well to the predicted ETVSS of 76.5% ± 12.5% (± SD). The C-statistic was 0.74 (95% CI 0.65-0.83), suggesting that the ability of the ETVSS to discriminate failures from successes was good. Secondary ETV was found to have a hazard ratio for failure of 4.2 (95% CI 2.4-7.2) compared with primary ETV (p < 0.001). The complication rate was 9.3% with no deaths. At the first radiological follow-up, the increased size of ventricles had a hazard ratio for failure of 3.0 (95% CI 1.5-6.0) compared with patients in whom ventricle size either remained stable or decreased (p = 0.002).

CONCLUSIONS

The ETVSS closely predicts the actual success of ETV, fitting the statistical model well. Shortcomings of the model were identified in overestimating success in patients with ETVSS ≤ 70, which may be attributable to the poor success of secondary ETVs in the authors' patient population.