Neuroendoscopic biopsy of ventricular tumors: a multicentric experience

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.

Neuroendoscopy in the management of pineal region tumours in children

INTRODUCTION

Pineal region tumours (PRTs) are more common in children and represent a wide variety of lesions. The practise of a radiation test dose is obsolete and a biochemical/histological diagnosis is recommended before further therapy. Many patients present with hydrocephalus. Advances in neuroendoscopic techniques have allowed safe and effective management of this obstructive hydrocephalus with an opportunity to sample cerebrospinal fluid (CSF) and obtain tissue for histopathology. Definitive surgery is required in less than a third. Endoscopic visualisation and assistance is increasingly used for radical resection, where indicated.

METHODOLOGY

Our experience of endoscopic surgery for paediatric PRTs from 2002 to 2021 is presented. All patients underwent MRI with contrast. Serum tumour markers were checked. If negative, endoscopic biopsy and endoscopic third ventriculostomy (ETV) were performed; and CSF collected for tumour markers and abnormal cells. For radical surgery, endoscope-assisted microsurgery procedures were performed to minimise retraction, visualise the extent of resection and confirm haemostasis.

RESULTS

M:F ratio was 2:1. The median age of presentation was 11 years. Raised ICP (88.88%) was the commonest mode of presentation. Nineteen patients had pineal tumours, one had a suprasellar and pineal tumour, one had disseminated disease, while six had tectal tumours. The ETB diagnosis rate was 95.45%, accuracy rate was 83.3% and ETV success rate was 86.96%.

CONCLUSION

Neuroendoscopy has revolutionised the management of paediatric PRTs. It is a safe and effective procedure with good diagnostic yield and allows successful concurrent CSF diversion, thereby avoiding major surgeries and shunt implantation. It is also helpful in radical resection of lesions, where indicated.

Concomitant, Single Burr Hole Endoscopic Third Ventriculostomy and Tumor Biopsy for Pineal Lesions: Feasibility, Safety, and Benefits

Obtaining a prompt diagnosis, avoiding indwelling ventriculoperitoneal shunt, and enhancing the predictive value of pathologic examinations are only some of the advantages conferred by a simultaneous third ventriculostomy and tumor biopsy in patients with pineal region tumors. The objective of this study was to retrospectively search the literature on concomitant, single burr hole endoscopic third ventriculostomy (ETV) and tumor biopsy (TB) for pineal region tumors and to analyze the feasibility, surgical safety, and benefits of these 2 combined procedures. Consequently, a comprehensive, systematic literature search was performed in compliance with the updated PRISMA 2020 guidelines within electronic databases MEDLINE/PubMed, EMBASE, PLOS, and Cochrane Library. Statistical analysis was performed with IBM SPSS 28.0.1.1(14), using Kendall's and Spearman's tests, with a P < 0.05 considered significant. A total of 25 studies were selected and included in this review, for a total of 368 patients (mean age 20.6 years; range 1-86 years; SD 17.5). More than two-thirds of the procedures were operated with a rigid endoscope and 27.6% were performed with either a flexible endoscope, a combination of the 2, or not otherwise specified. Germinoma represented the most frequent diagnosis (20.1%) followed by astrocytoma (12.9%) and pineocytoma (9.9%). The single-entry approach allowed a correct histologic diagnosis in 88.7% of the examined cases. Summing up, concomitant ETV and TB represent a valuable option for the management of non-communicating hydrocephalus and the initial assessment of pineal region tumors. The histologic confirmation rate was 88.7% in the examined cohort, with only 10% of the biopsies yielding inconclusive results.

Simultaneous biportal endoscopic management of pineal region tumors in patients with obstructive hydrocephalus: technical notes

BACKGROUND

The goal of this study is to show the feasibility and benefits of using the simultaneous biportal endoscopic procedure to treat pineal tumors in patients with obstructive hydrocephalus.

METHODS

We retrospectively reviewed three patients with pineal tumors and acute obstructive hydrocephalus who were treated in one session with a frameless stereotactic guided simultaneous biportal endoscopic third ventriculostomy and endoscopic tumor biopsy performed through two separate ports using one rigid ventriculoscope.

RESULTS

In the three patients, ventriculostomy and endoscopic biopsies were conducted. There was no death or morbidity throughout the 45-min procedure. All of the patients' histological findings were confirmed. Germinoma was diagnosed in two patients who recieved postoperative radiotherapy, and the third patient diagnosed with a pineocytoma. Magnetic resonance imaging with flow-sensitive sequences was used to confirm ventriculostomy patency in all patients 6 months after the surgery.

CONCLUSION

Biportal endoscopic approach enables better visual control of both procedures. Furthermore, it allows the surgeon to safely pass the ventriculoscope via the foramen of monro, even if it is narrow. Moreover, during endoscopic tumor biopsy and third ventriculostomy, the intracranial pressure can be smoothly managed using the outlet tubes accessible. This treatment may be an alternative to traditional uniportal endoscopic operations in certain patients.

Endoscopic third ventriculostomy complications: avoidance and management in a stepwise manner

Background

Various complications of endoscopic third ventriculostomy (ETV) have been described. One has to recognize these complications and learn how to avoid them.

Methods

We performed a literature review regarding the reported complications of ETV procedures discussed in a correlated manner with the surgical steps. Furthermore, we reviewed the technical notes described by experienced neuroendoscopists, including surgical indications, choice of the endoscopic entry point and trajectory, anatomic orientation, proper bleeding control and tight closure, to prevent and deal with such complications.

Results and conclusion

A lesson learned that comprehensive knowledge of ventricular anatomy with proper orientation by studying the preoperative images is mandatory and one should be aware of all complication types and rates.

Joint synthesis and registration network for deformable MR-CBCT image registration for neurosurgical guidance

Objective.The accuracy of navigation in minimally invasive neurosurgery is often challenged by deep brain deformations (up to 10 mm due to egress of cerebrospinal fluid during neuroendoscopic approach). We propose a deep learning-based deformable registration method to address such deformations between preoperative MR and intraoperative CBCT.Approach.The registration method uses a joint image synthesis and registration network (denoted JSR) to simultaneously synthesize MR and CBCT images to the CT domain and perform CT domain registration using a multi-resolution pyramid. JSR was first trained using a simulated dataset (simulated CBCT and simulated deformations) and then refined on real clinical images via transfer learning. The performance of the multi-resolution JSR was compared to a single-resolution architecture as well as a series of alternative registration methods (symmetric normalization (SyN), VoxelMorph, and image synthesis-based registration methods).Main results.JSR achieved median Dice coefficient (DSC) of 0.69 in deep brain structures and median target registration error (TRE) of 1.94 mm in the simulation dataset, with improvement from single-resolution architecture (median DSC = 0.68 and median TRE = 2.14 mm). Additionally, JSR achieved superior registration compared to alternative methods-e.g. SyN (median DSC = 0.54, median TRE = 2.77 mm), VoxelMorph (median DSC = 0.52, median TRE = 2.66 mm) and provided registration runtime of less than 3 s. Similarly in the clinical dataset, JSR achieved median DSC = 0.72 and median TRE = 2.05 mm.Significance.The multi-resolution JSR network resolved deep brain deformations between MR and CBCT images with performance superior to other state-of-the-art methods. The accuracy and runtime support translation of the method to further clinical studies in high-precision neurosurgery.

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.

Deformable MR-CT image registration using an unsupervised, dual-channel network for neurosurgical guidance

PURPOSE

The accuracy of minimally invasive, intracranial neurosurgery can be challenged by deformation of brain tissue - e.g., up to 10 mm due to egress of cerebrospinal fluid during neuroendoscopic approach. We report an unsupervised, deep learning-based registration framework to resolve such deformations between preoperative MR and intraoperative CT with fast runtime for neurosurgical guidance.

METHOD

The framework incorporates subnetworks for MR and CT image synthesis with a dual-channel registration subnetwork (with synthesis uncertainty providing spatially varying weights on the dual-channel loss) to estimate a diffeomorphic deformation field from both the MR and CT channels. An end-to-end training is proposed that jointly optimizes both the synthesis and registration subnetworks. The proposed framework was investigated using three datasets: (1) paired MR/CT with simulated deformations; (2) paired MR/CT with real deformations; and (3) a neurosurgery dataset with real deformation. Two state-of-the-art methods (Symmetric Normalization and VoxelMorph) were implemented as a basis of comparison, and variations in the proposed dual-channel network were investigated, including single-channel registration, fusion without uncertainty weighting, and conventional sequential training of the synthesis and registration subnetworks.

RESULTS

The proposed method achieved: (1) Dice coefficient = 0.82±0.07 and TRE = 1.2 ± 0.6 mm on paired MR/CT with simulated deformations; (2) Dice coefficient = 0.83 ± 0.07 and TRE = 1.4 ± 0.7 mm on paired MR/CT with real deformations; and (3) Dice = 0.79 ± 0.13 and TRE = 1.6 ± 1.0 mm on the neurosurgery dataset with real deformations. The dual-channel registration with uncertainty weighting demonstrated superior performance (e.g., TRE = 1.2 ± 0.6 mm) compared to single-channel registration (TRE = 1.6 ± 1.0 mm, p < 0.05 for CT channel and TRE = 1.3 ± 0.7 mm for MR channel) and dual-channel registration without uncertainty weighting (TRE = 1.4 ± 0.8 mm, p < 0.05). End-to-end training of the synthesis and registration subnetworks also improved performance compared to the conventional sequential training strategy (TRE = 1.3 ± 0.6 mm). Registration runtime with the proposed network was ∼3 s.

CONCLUSION

The deformable registration framework based on dual-channel MR/CT registration with spatially varying weights and end-to-end training achieved geometric accuracy and runtime that was superior to state-of-the-art baseline methods and various ablations of the proposed network. The accuracy and runtime of the method may be compatible with the requirements of high-precision neurosurgery.

Simultaneous single-trajectory endoscopic biopsy and third ventriculostomy in pediatric pineal region tumors

Pineal region tumors have different pathological tumors and their optimal management remains controversial. Advancements in neuroendoscopy have led to the ability to simultaneously treat the hydrocephalus and obtain a tissue diagnosis. A retrospective review of 34 patients with pineal region tumors in Beijing Tiantan hospital from the year 2016 to 2018 was undertaken. A single bur hole for both procedures was used successfully in all patients. Once pathologic diagnosis is made, the subsequent management of different tumors is dependent on response to therapy, the tumor markers and original pathology. Follow-up period was 4-26 months. All 34 cases presented with hydrocephalus and increased intracranial pressure manifestations. Elevated blood tumor markers were found in seven cases. The neuroendoscopic biopsy was diagnostic in 32 samples (94.1%) and nondiagnostic (gliosis) in two patients. 21 cases were germinomas, five cases were tectal astrocytomas, two cases were pineoblastomas, two cases were non-germinomatous germ-cell tumours (NG-GCTs) and 1 case immature teratoma and glioblastoma respectively. During the follow-up period, all germinomas but one case with elevated blood α-fetoprotein received craniotomy with a final diagnosis of NG-GCT received radiotherapy and chemotherapy. Four tectal astocytomas, two pineoblastomas and two NG-GCTs received subsequent open surgery due to progressive development, the pathological data was concordant with the initial endoscopic biopsy sample. An additional VP shunt was inserted in one tectal astrocytoma who have hydrocephalus after craniotomy. Except for 18 cases of transient fever and a case with intratumoral hemorrhage, there was no other significant complications, cognitive disorder and no death. The simultaneous single-trajectory endoscopic technique permits not only to control hydrocephalus but also to obtain histological diagnosis with a low incidence of complication and higher safety. Providing meaningful pathological data, endoscopic biopsies could lead to an appropriate management decision. Especially, it is favored as an early step in the management of patients with marker-negative tumors.

Neuroendoscopy in the Surgical Management of Lateral and Third Ventricular Tumors: Looking Beyond Microneurosurgery

Background

Intraventricular tumors pose a surgical challenge because of the difficulty in reaching their deep location through safe corridors and their adherence or proximity to vital neurovascular structures. Although microneurosurgery is the mainstay of surgical management, neuroendoscopy aided by adjuncts, namely, navigation and ultrasonic aspirators, has made a great contribution to improving surgical results.

Objective

This article reviews the experience of a neurosurgical unit with endoscopic procedures for intraventricular tumors. The current indications, benefits, and complications of neuroendoscopy are described.

Materials and Methods

This is a retrospective, observational study of lateral and third ventricular tumors tackled either purely with an endoscope or with its assistance over 19 years in a single unit at Bombay Hospital Institute of Medical Sciences, Mumbai.

Results

Of a total of 247 operated patients with intraventricular tumors, 85 cases operated using an endoscope were included. The majority of the patients had a tumor in the third ventricle (n = 62), whereas 23 patients had tumor in the lateral ventricle. The most common pathologies were colloid cyst and arachnoid cyst (n = 18). An endoscope was used for microsurgical assisted excision of tumors in 31 cases, biopsy in 24, cyst fenestration in 23, and pure endoscopic excision in seven cases.

Conclusion

Microsurgery remains the gold standard for the removal of giant, vascular intraventricular tumors. However, endoscopic fenestration or excision of cysts and biopsy have become better alternatives in many cases. Endoscope-assisted microsurgery affords safety and helps in achieving a more complete excision.

A clinical approach to parasellar lesions in the transition age

Many reviews have summarised the pathology and management of the parasellar region in adult patients, although an analysis of these aspects in the transition years, from puberty onset to the age of peak bone mass, has been lacking. A comprehensive search of English-language original articles, published from 2000 to 2020, was conducted in the MEDLINE database (December 2019 to March 2020). We selected all studies regarding epidemiology, diagnosis and management of the following parasellar lesions: germinoma, craniopharyngioma, Langerhans cell histiocytosis, optic glioma, hypothalamic hamartoma, tuber cinereum hamartoma, cranial chordoma, Rathke cleft cyst, hypophysitis and hypothalamitis during the transition age from childhood to adulthood. In the present review, we provide an overview of the principal parasellar lesions occurring in the transition age. Symptoms are usually a result of the mass effect of the lesions on nearby structures, as well as anterior pituitary deficits. Diabetes insipidus occurs frequently in these patients. In this age group, pubertal developmental disorders may be more evident compared to other stages of life. Parasellar lesions in the transition age mostly include neoplastic lesions such as germinomas, hamartomas, optic gliomas, craniopharyngiomas Langerhans cell histiocytosis and chordomas, and rarely inflammatory lesions (hypophysitis, hypothalamitis). There are limited data on the management of parasellar lesions in the transition age. Endocrine evaluation is crucial for identifying conditions that require hormonal treatment so that they can be treated early to improve the quality of life of the individual patient in this complex age range. The clinical approach to parasellar lesions involves a multidisciplinary effort.

Cytologic Features of Ventricular Tumors of the Central Nervous System: A Review with Emphasis on Diff-Quik Stained Smears

BACKGROUND

Neoplasms from the ventricular system share a common location but have highly variable histogenesis. Many are slowly growing tumors that behave in a benign fashion. They can be classified as primary and secondary tumors. The most common primary tumors are ependymomas, subependymomas, subependymal giant cell astrocytomas, central neurocytomas, choroid plexus tumors, meningiomas, germinomas, pineal parenchymal tumors, papillary tumors of the pineal region, chordoid gliomas, rosette-forming glioneuronal tumors of the fourth ventricle, and craniopharyngiomas. Pilocytic astrocytomas, medulloblastomas, and atypical teratoid/rhabdoid tumors often show secondary involvement of the ventricular system.

SUMMARY

Advances in neurosurgery have facilitated access to the ventricular system increasing the number of cases in which such tumors can be biopsied. In this context, cytology has been proven to be an extremely useful diagnostic tool during intraoperative pathologic consultations. Many ventricular tumors are infrequent, and the cytologic information available is limited. In this review, we describe the cytologic features of the uncommon ventricular tumors and report on unusual findings of the more common ones. For the cytologic evaluation of brain tumors, many neuropathologists prefer formalin fixation and hematoxylin and eosin staining. In this review, we highlight the cytologic findings as seen with Diff-Quik, a very popular staining method among cytopathologists. In fact, when pathologists are unfamiliar with cytology, it is common to request the assistance of cytopathologists during the evaluation of intraoperative procedures. Key Message: Ventricular tumors of the central nervous system comprise a group of heterogeneous tumors with very different cytologic features. The cytomorphology of these tumors, including rare entities, is often very characteristic, allowing a precise recognition during intraoperative pathologic consultations. Diff-Quik is a valuable staining method that can be used alone or as a complement to hematoxylin and eosin staining. Diff-Quik allows for clear visualization of the overall architecture, cytoplasmic details, and extracellular material.

Endoscopic needle biopsy of thalamic tumors: technical note

INTRODUCTION

Neuroendoscopic biopsy represents the procedure of choice for pure intraventricular lesions. Instead, in case of deep-seated paraventricular tumors, with intact ependyma, the advantage of neuroendoscopy over stereotactic biopsy is not so evident, because the lesion is not under direct vision; the tissue sample may be limited to more superficial ependymal layer, and bleeding may obscurate vision. Also, stereotactic biopsy may reserve additional problems for these lesions: inaccuracy caused by leak of cerebrospinal fluid and increased risk of severe hemorrhage due to damage of the ependymal vessels.

CASE REPORTS

We report two cases of young children affected by thalamic tumors that were biopsied using a modification of a recently proposed technique: endoscopic visual control, neuronavigated needle biopsy.

CONCLUSION

This technique may combine the accuracy of a stereotactic needle biopsy with the advantage of visual control on site of ependymal puncture and possibility of immediate bleeding control.

Endoscopic Third Ventriculostomy and Simultaneous Tumor Biopsy in Pineal Region Tumors using the "Single Burr Hole" Technique: An Analysis of 34 Cases

Background

Pineal region tumors often present with hydrocephalus. Endoscopic third ventriculostomy (ETV) and simultaneous tumor biopsy remain a minimally invasive procedure offering both diagnostic and therapeutic advantages in the management of these tumors. However, different operative techniques have been described in the literature.

Aim

The aim is to study the ETV success rate, diagnostic rate of simultaneous tumor biopsy, complications, and follow-up of patients of pineal region tumors managed with ETV and simultaneous tumor biopsy using the single burr hole technique.

Methods

The study was performed by retrospectively reviewing the records of patients of pineal region tumors managed by simultaneous ETV and tumor biopsy using a "single burr hole" technique from January 2012 to December 2019.

Results

Thirty-four patients (22 males and 12 females) with a mean age of 28.7 years were analyzed. ETV was successful in relieving hydrocephalus in 29 (87.8%) patients. Three patients needed a ventriculoperitoneal shunt, and one required Ommaya reservoir placement for persistent hydrocephalus. Histological diagnosis was successfully established in 26 (78.8%) patients. There were two procedure-related mortalities. Two patients underwent craniotomy and tumor excision subsequently. Radiotherapy was given to 11 patients, and 9 patients were managed by observation alone. The mean follow-up of our study was 15.8 months.

Conclusions

Simultaneous ETV and tumor biopsy using a single burr hole technique is a safe, minimally invasive procedure for the management of pineal region tumors.

A Review of Common Endoscopic Intracranial Approaches

With the evolution of surgical techniques, endoscopy has emerged as a suitable alternative to many instances of more invasive methods. In this review article, we aim to discuss the endoscopic advancements, procedural details, indications, and outcomes of the most commonly practiced neuroendoscopic procedures. We have also summarized the uses, techniques, and challenges of neuroendoscopy in select neurosurgical pathologies.

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.

Calcifying Pseudoneoplasm of Neuraxis (CAPNON) in the Posterior Third Ventricle-Challenge for Neuroendoscopy

BACKGROUND

We report the first case of a purely intraventricular calcifying pseudoneoplasm of neuraxis (CAPNON) in the posterior third ventricle.

CASE DESCRIPTION

A 63-year-old male without any previous medical history presented with Hakim triad. Imaging showed a calcified lesion of the posterior third ventricle with hydrocephalus. An endoscopic third ventriculostomy was performed. Endoscopic removal or debulking of the lesion was impossible due to its rock-hard consistency, and thus the procedure was aborted after biopsy.

CONCLUSIONS

When encountering such calcified lesions within the ventricular system, especially in proximity to eloquent regions, the decision making process should include the hard consistency and parenchymal adhesions as obstacles to neuroendoscopic removal. Even for biopsy, a higher morbidity rate compared with typical soft tumors should be assumed. Although data on intraventricular CAPNON is limited, biopsy of the lesion and treatment of associated hydrocephalus appear to be the primary neurosurgical goals, followed by imaging surveillance.

Placental alkaline phosphatase levels in cerebrospinal fluid can have a decisive role in the differential diagnosis of intracranial germ cell tumors

OBJECTIVE

Placental alkaline phosphatase (PLAP) in CSF can provide a very high diagnostic value in cases of intracranial germ cell tumors (GCTs), especially in pure germinomas, to the level of not requiring histological confirmation. Unlike other tumor markers, reliable data analysis with respect to the diagnostic value of PLAP serum or CSF levels has not been available until now. This is the first systematic and comprehensive study examining the diagnostic value of CSF PLAP in patients with intracranial GCTs.

METHODS

From 2004 to 2014, 74 patients (average age 19.6 ± 10.6 years) with intracranial GCTs were evaluated using PLAP from their CSF and histological samples. Chemiluminescent enzyme immunoassay was utilized to measure CSF PLAP in the following tumor sites: pineal (n = 32), pituitary stalk, suprasellar (n = 16), basal ganglia (n = 15), intraventricular (n = 9), and cerebellar (n = 5) regions. In addition to classifying GCT cases, all patients underwent tumor biopsy for correlation with tumor marker data.

RESULTS

PLAP in combination with other tumor markers resulted in extremely high sensitivity and specificity of the diagnostic value of intracranial GCTs. Intracranial GCT cases were classified into 1) germinomas, both "pure" and syncytiotrophoblastic giant cell types (n = 38); 2) nongerminomatous GCTs, choriocarcinomas (n = 9) and teratomas (n = 4); and 3) nongerminomas, other kinds of tumors (n = 23). Consequently, all patients received chemoradiation therapy based on elevation of PLAP and the histopathological results. It was also speculated that the level of PLAP could show the amount of intracranial germ cell components of a GCT. PLAP was 100% upregulated in all intracranial germinoma cases. The absence of CSF PLAP proved that the tumor was not a germinoma.

CONCLUSIONS

The current study is the first systematic and comprehensive examination of the diagnostic value of the tumor marker PLAP in pediatric patients with intracranial GCT. Using the level of PLAP in CSF, we were able to detect the instances of intracranial germinoma with very high reliability, equivalent to a pathological diagnosis.

Pineal region tumors: Long-term results of endoscopic third ventriculostomy and concurrent tumor biopsy with a single entry approach in a series of 64 cases

OBJECTIVES

Endoscopic third ventriculostomy and concurrent biopsy is increasingly used in management of the pineal region tumors. Our objective was to assess the results of single entry approach to surgically manage the tumors of the pineal region.

PATIENTS AND METHODS

A retrospective study was designed, and a series of 64 consecutive patients (31 male, 33 female) with pineal region tumor undergoing endoscopic third ventriculostomy and concurrent biopsy of the tumor was undertaken.

RESULTS

A total of 64 patients underwent simultaneous endoscopic third ventriculostomy and biopsy of the pineal tumors with a single entry approach. A positive initial diagnosis was established in 97% of patients. 5 patients (7%) required the insertion of an external ventricular drain which was removed in all patients after 72 h but in one case (1%) undergoing permanent VP shunt insertion. The postoperative complications were divided into two transient and permanent complications. The transient complications included intraventricular hemorrhage (18%), seizure (1 to two episodes of seizure) (5%), diabetes insipidus (3%) and meningitis (3%) all were successfully managed. The only permanent complication was memory deficits occurred in one patient (1%). There was no mortality rate in current study.

CONCLUSION

The results of this study support the safety and efficacy of endoscopic third ventriculostomy and concurrent biopsy of the pineal region tumors as a less invasive surgical method associated with low morbidity and mortality rate. Our data demonstrated how simultaneous endoscopic third ventriculostomy and biopsy of the pineal region tumors with a single entry approach can produce favorable results.

De Novo Pineal Region Germinoma in the Seventh Decade of Life: A Case Report

Germ cell tumors typically occur in children and adolescents. We here report a rare case of de novo pineal region germinoma in the seventh decade of life. A 62-year-old man presented with double vision. Computerized tomography and magnetic resonance imaging (MRI) identified a heterogeneously enhanced tumor with calcification in the pineal region with ventricular dilatation due to aqueduct stenosis. The tumor had not been observed at all on MRI obtained 2 years previously. The patient underwent endoscopic biopsy and third ventriculostomy for the obstructive hydrocephalus. The tumor was histopathologically diagnosed as a pure germinoma. The patient underwent radiomonotherapy, resulting in his complete remission, which was confirmed by a series of follow-up MRI studies and hematological examinations. Intracranial germinoma should be considered in the differential diagnosis of pineal region tumors regardless of age, even though the tumor was undetectable on the previous neuroimaging.

Visual-Controlled Endoscopic Biopsy of Paraventricular Intraparenchymal Tumors

OBJECTIVE

Frame-based stereotaxy represents the gold standard for biopsy of deep-seated lesions. Visual control of possible bleeding in these lesions is not possible. Neuroendoscopic biopsy represents an alternative procedure for tissue sampling in deep-seated intraventricular lesions. The authors present a technique for transventricular-navigated endoscopic biopsy of lesions that are located in the paraventricular region.

METHODS

Biopsy of paraventricular pathologies was performed in 6 male and 6 female patients between March 2013 and September 2018. The patient age ranged from 18 to 82 years. All patients underwent a pure endoscopic procedure over a burr hole trepanation supported by frameless navigation of the sedan probe.

RESULTS

Histologic diagnoses were established in all biopsies. In all patients, a direct control of the biopsy area was feasible, and hemostasis could be obtained. In 5 patients, endoscopic third ventriculostomy was performed first due to obstructive hydrocephalus. In 1 patient suffering from obstructive hydrocephalus, a pellucidotomy was performed. In 9 cases, the initial postoperative course was uneventful. Three patients suffered from persistent hydrocephalus and had to be treated with ventriculoperitoneal shunt insertion.

CONCLUSIONS

Endoscopically conducted biopsies with the aid of navigated tracking of the probe represent a possible additional technique in selected paraventricular intraparenchymal pathologies. The endoscopic approach enables the direct visualization of the intraventricular surface and its vessels. In contrast to standard stereotactic biopsy, direct visual control of hemostasis can be obtained even in paraventricular tumors.

Neuroendoscopic Intraoperative Ultrasound-Guided Technique for Biopsy of Paraventricular Tumors

Different tumors can be encountered in the paraventricular regions, and whereas their deep location often make them difficult to access surgically, they may be amenable to chemotherapy and/or radiotherapy. Therefore, tumor biopsy and histologic diagnosis are mandatory to optimize treatment. Different technical procedures have been recommended; the neuroendoscopic approach is accepted and widely used, in particular with an enlarged ventricular system. However, specifically with paraventricular tumors, tissue sampling may be challenging. In such a scenario, the use of intraoperative ultrasonography technique can add some advantages regarding diagnostic accuracy and procedure safety. Accordingly, in this study we describe a novel technical procedure in 7 selected patients in whom tumor tissue biopsy was performed in a coupled neuroendoscopic and ultrasound-guided environment. We define a neuroendoscopic intraoperative ultrasound technique. The main advantages of this technique are the identification of the tumor that may not been clearly identified underneath the ventricular ependymal through the neuroendoscopic window alone, and furthermore, that this technique gives the possibility to detect the depth of the needle advance∖ment in the selected tissue while labeling the lesion beneath the ventricular ependyma. Moreover, intraoperative ultrasonography can reveal in a real-time fashion intracranial hemorrhages that may occur after tissue biopsy, therefore providing a useful tool to achieve valid and directed hemostasis when needed.

Intraventricular bone dust migration after neuroendoscopy: report of 2 cases

Neuroendoscopy has demonstrated safety and efficacy in the treatment of a host of pediatric neurosurgical pathologies. With the increase in its applicability, several associated complications have been described in the literature. A common practice in pediatric neurosurgery is the use of Gelfoam sponge pledget in the burr hole, followed by bone fragments and dust (obtained from the created burr hole), to cover the dural defect. This technique is used to enhance burr hole sealing and potentially prevent CSF leakage from the surgical site. Reports on intracranial bone dust migration associated with this technique are scarce. The authors report 2 cases of intracranial migration of bone fragments after an endoscopic third ventriculostomy and an endoscopic colloid cyst resection. The bone fragment migration was thought to be caused by negative pressure from a lumbar puncture in one case and external trauma to the head in the other. As endoscopy becomes more widely used, it is important to be aware of this potential complication that may in some cases require an intervention. A review of the cases reported in the literature is provided and a technique is suggested to help prevent this complication.

A momentum-based diffeomorphic demons framework for deformable MR-CT image registration

Neuro-navigated procedures require a high degree of geometric accuracy but are subject to geometric error from complex deformation in the deep brain-e.g. regions about the ventricles due to egress of cerebrospinal fluid (CSF) upon neuroendoscopic approach or placement of a ventricular shunt. We report a multi-modality, diffeomorphic, deformable registration method using momentum-based acceleration of the Demons algorithm to solve the transformation relating preoperative MRI and intraoperative CT as a basis for high-precision guidance. The registration method (pMI-Demons) extends the mono-modality, diffeomorphic form of the Demons algorithm to multi-modality registration using pointwise mutual information (pMI) as a similarity metric. The method incorporates a preprocessing step to nonlinearly stretch CT image values and incorporates a momentum-based approach to accelerate convergence. Registration performance was evaluated in phantom and patient images: first, the sensitivity of performance to algorithm parameter selection (including update and displacement field smoothing, histogram stretch, and the momentum term) was analyzed in a phantom study over a range of simulated deformations; and second, the algorithm was applied to registration of MR and CT images for four patients undergoing minimally invasive neurosurgery. Performance was compared to two previously reported methods (free-form deformation using mutual information (MI-FFD) and symmetric normalization using mutual information (MI-SyN)) in terms of target registration error (TRE), Jacobian determinant (J), and runtime. The phantom study identified optimal or nominal settings of algorithm parameters for translation to clinical studies. In the phantom study, the pMI-Demons method achieved comparable registration accuracy to the reference methods and strongly reduced outliers in TRE (p [Formula: see text] 0.001 in Kolmogorov-Smirnov test). Similarly, in the clinical study: median TRE  =  1.54 mm (0.83-1.66 mm interquartile range, IQR) for pMI-Demons compared to 1.40 mm (1.02-1.67 mm IQR) for MI-FFD and 1.64 mm (0.90-1.92 mm IQR) for MI-SyN. The pMI-Demons and MI-SyN methods yielded diffeomorphic transformations (J  >  0) that preserved topology, whereas MI-FFD yielded unrealistic (J  <  0) deformations subject to tissue folding and tearing. Momentum-based acceleration gave a ~35% speedup of the pMI-Demons method, providing registration runtime of 10.5 min (reduced to 2.2 min on GPU), compared to 15.5 min for MI-FFD and 34.7 min for MI-SyN. The pMI-Demons method achieved registration accuracy comparable to MI-FFD and MI-SyN, maintained diffeomorphic transformation similar to MI-SyN, and accelerated runtime in a manner that facilitates translation to image-guided neurosurgery.

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.

Endoscopic biopsy of intra- and paraventricular brain tumors

Introduction

Selection of the optimal treatment method of intra- and paraventricular tumors often requires histopathological verification that can be obtained by endoscopic biopsy.

Aim

To discuss the usefulness of the method in their own experience.

Material and methods

The results of 32 biopsies carried out during a 15-year period were reviewed retrospectively. All tumors were located supratentorially, 25 of them were intraventricular and 7 paraventricular. In 18 patients the tumor was accompanied by internal hydrocephalus. If the ventricular system was narrow, the biopsy was supported by a neuronavigation system. A rigid neuroendoscope was used. The obtained material was subjected to intraoperative and final histopathological examination.

Results

Viable diagnostic material was obtained from all patients. In 11 patients with tumor of the posterior portion of the third ventricle, cerebrospinal fluid was collected additionally for diagnostic tests. In 9 patients with obstructive hydrocephalus concomitant third ventriculostomy was performed. In 4 patients with tumor of the interventricular foramen, the tumor mass was reduced and in 2 cases septostomy was performed. In 3 (9.4%) cases the histopathological diagnosis was descriptive and did not explain the nature of the lesion. Four biopsies resulted in persistent bleeding, in 3 patients transient memory impairments were observed, and in 1 patient an epileptic seizure occurred. Five patients needed ventriculoperitoneal shunt placement.

Conclusions

Endoscopic biopsy is a safe method to verify the histopathological nature of intra- and paraventricular lesions. It enables sampling of cerebrospinal fluid, reduction of tumor size, and in cases of coexisting obstructive hydrocephalus also third ventriculostomy or septostomy.

Neuroendoscopic management of posterior third ventricle ependymoma with intraaqueductal and fourth ventricle extension: a case report and review of the literature

INTRODUCTION

Posterior third ventricle ependymomas with intraaqueductal extension are relatively infrequent lesions. Its surgical management represents a formidable technical challenge and includes a wide variety of approaches. Minimally invasive surgery including the endoscopic management can play a crucial role to obtain an optimal clinical outcome.

PATIENTS AND METHODS

We report the clinical outcome of an 11-year-old female patient with a 6-year history of recurrent episodes of headache and vomiting. On brain MRI a posterior third ventricle lesion with extension to the aqueduct of Sylvius and fourth ventricle, and associated hydrocephalus was observed.

RESULTS

Our management of the lesion included a two-step endoscopic surgery: first an anterior third ventriculostomy and biopsy of the lesion that was reported to be a low-grade ependymoma, and posteriorly an endoscopic-assisted resection of the lesion. Clinical outcome was optimal without neurological sequelae. The postoperative MRI showed a thickened ependymal area on the tumor base of implantation. It was considered to be a remnant of the lesion and subsequently treated with radiotherapy.

CONCLUSION

Posterior third ventricle ependymomas with intraaqueductal extension can be endoscopically managed to obtain a successful outcome.

Pitfalls of Neuroendoscopic Biopsy of Intraventricular Germ Cell Tumors

OBJECTIVE

A neuroendoscopic biopsy has become common for the diagnosis of ventricular tumors. However, its utility in patients with germ cell tumors (GCTs) has not been well discussed. We examined the usefulness and pitfalls of neuroendoscopic biopsies of intraventricular GCTs at a single institution.

METHODS

We retrospectively studied 21 consecutive patients diagnosed with GCTs by a neuroendoscopic biopsy of the ventricular region via the lateral ventricle. We examined the localization of tumors, histologic diagnoses using biopsies, surgical complications, and consistency of the diagnosis at the latest follow-up.

RESULTS

Tumor specimens were obtained from a pineal lesion (n = 20), neurohypophysial lesion (n = 5), and lateral ventricular wall lesion (n = 2). In 5 patients, the specimens were obtained from multiple areas. The initial diagnoses were pure germinoma (n = 16), immature teratoma (n = 1), yolk sac tumor (n = 1), and mixed GCT (n = 3). Six of 21 patients needed a second transcranial removal of enhanced residual lesions in the course of the treatment. A discrepancy in the histologic diagnosis between 2 surgeries occurred in 3 patients: All 3 patients had a new diagnosis of teratoma component following transcranial surgery. No postoperative mortality or permanent morbidity related to the neuroendoscopic procedures was noted.

CONCLUSION

Neuroendoscopic biopsies are safe and useful for obtaining reliable histologic diagnoses in the management of GCTs. However, for GCTs with mixed histology, biopsies are susceptible to diagnostic errors, especially missing detecting a component of teratoma.

Transcortical Endoscopic Surgery for Intraventricular Lesions

To review recent advances in endoscopic techniques for treating intraventricular lesions via transcortical passage. Articles in PubMed published since 2000 were searched using the keywords ‘endoscopy,’ ‘endoscopic,’ and ‘neuroendoscopic.’ Of these articles, those describing intraventricular lesions were reviewed. Suprasellar arachnoid cysts (SACs) can be treated with ventriculo-cystostomy (VC) or ventriculo-cysto-cisternostomy (VCC). VCC showed better results compared to VC. Procedure type, fenestration size, stent placement, and aqueductal patency may affect SAC prognosis. Colloid cysts can be managed using a transforaminal approach (TA) or a transforaminal-transchoroidal approach (TTA). However, TTA may result in better exposure compared to TA. Intraventricular cysticercosis can be cured with an endoscopic procedure alone, but if pericystic inflammation and/or ependymal reaction are seen, third ventriculostomy may be recommended. Tumor biopsies have yielded successful diagnosis rates of up to 100%, but tumor location, total specimen size, endoscope type, and vigorous coagulation on the tumor surface may affect diagnostic accuracy. An ideal indication for tumor excision is a small tumor with friable consistency and little vascularity. Tumor size, composition, and vascularity may influence a complete resection. SACs and intraventricular cysticercosis can be treated successfully using endoscopic procedures. Endoscopic procedures may represent an alternative to surgical options for colloid cyst removal. Solid tumors can be safely biopsied using endoscopic techniques, but endoscopy for tumor resection still results in considerable challenges.

Endoscopic Treatment of an Adult with Tegmental Astrocytoma Accompanied by Cerebrospinal Fluid Dissemination

Midbrain gliomas are relatively rare neoplasms with a generally benign prognosis, with dissemination or metastasis not previously reported. We describe here a woman, in whom magnetic resonance imaging scans showed hydrocephalus and a tegmental lesion in the upper aqueduct. Endoscopic third ventriculostomy and biopsy were performed; during surgery, a second small lesion was observed in the infundibular recess. Histologically, the two lesions had the characteristics of low grade astrocytoma, suggesting that the midbrain astrocytoma may have been disseminated via the cerebral spinal fluid to the infundibular recess. Postoperatively this patient received radiotherapy for nearly one month. Although patients with these tumors are not usually administered adjunctive therapy, radiation and, combined modality therapy, including surgery, radiotherapy, and chemotherapy, may be beneficial in patients with midbrain gliomas with dissemination.

Third Ventricular Cerebrospinal Fluid Cysts of Thalamic Origin: Review of Embryologic Origin, Presentation, and Management Strategies with a Case Series

OBJECTIVE

Third ventricular cerebrospinal fluid (CSF) cysts of thalamic origin are rare. The objective of this study is to review their possible pathogenesis, clinical presentation, and management strategies with a case series describing management via an endoscopic approach with fenestration using a single burr-hole technique.

METHODS

A systematic literature review of reported cases of thalamic cysts was conducted with further meta-analysis of CSF cysts that involve the third ventricle. The mode of presentation, pathologic analysis, surgical management, and outcomes were analyzed.

RESULTS

Twenty-two studies reported between 1990 and 2013 described 42 cases of thalamic cyst. Of those cases, 13 were consistent with CSF cyst that originated in the thalamus and involved the third ventricle. Eight cases (61.5%) were treated via endoscopic fenestration, 2 cases (15.4%) were surgically drained, 2 cases (15.4%) were stereotactically aspirated, and 1 case (7.69%) was observed. The most common presenting symptoms were gait disturbance (26.3%) and headaches (26.3%) followed by tremors (15.8%) and weakness (15.8%). In our series, a single burr-hole technique was a successful definitive treatment, with an average period of 23 months.

CONCLUSIONS

Third ventricular CSF cysts of thalamic origin most commonly present with hydrocephalus. They can be safely definitively treated via endoscopic fenestration to the CSF circulation using a single burr-hole technique. Long-term follow-up shows lasting improvement in symptoms without reaccumulation of the cyst.

Fluorescein-Guided Neuroendoscopy for Intraventricular Lesions: A Case Series

BACKGROUND: The benefits of neuroendoscopy in the pathological diagnosis of intra- and paraventricular tumors have already been shown in many neurosurgical studies. However, most authors agree that neuroendoscopic biopsies are not infrequently inconclusive due to small or inadequate samples, prompting the need for new diagnostic strategies.

OBJECTIVE: To describe a technique not previously reported in the literature, combining neuroendoscopy with angiofluorescein guidance for the pathological diagnosis of intra- and paraventricular tumors.

METHODS: The 4-mm steerable fiberscope used was equipped with dual observation modes for white light and fluorescein. Access was by the classical precoronal burr hole. After inspecting the ventricular system in white light, a 10-mg/kg dose of fluorescein sodium (FS) was administered intravenously to the patient. The endoscope was then switched to the blue light fluorescent mode to better localize the pathological tissue. The protocol had been submitted to the local ethics committee.

RESULTS: From September 2011 to March 2015, 9 consecutive patients (aged 1-56 yr) harboring intra- and paraventricular lesions prospectively underwent angiofluorescein-guided endoscopy. In all cases, a pathological diagnosis was obtained without complications. In 5 patients, an endoscopic third ventriculostomy, and, in 1 patient, a septostomy was performed during the same procedure. Fluorescein guidance definitely modified our site of biopsy in 4 cases.

CONCLUSION: In our experience, FS has proven to be a strong enhancer of all ventricular lesions presenting with a disrupted blood–brain barrier, including inflammatory processes. Fluorescein-guided neuroendoscopy appears to be a safe, economic method to improve diagnostic potential in ventricular lesions.

Endoscopic Reconstruction of CSF Pathways in Ventricular Tumors

Neuroendoscopy is now considered to be a minimally invasive surgical approach for expanding lesions bulging into the ventricle, and it is also considered to be a relevant tool for performing biopsy procedures, fenestration of cystic walls, or for performing tumor removal in selected cases. Furthermore, the use of neuroimaging and the accurate follow-up of brain tumor patients have allowed the documentation of tumoral and pseudotumoral cystic areas that cause the obstruction of cerebrospinal fluid (CSF) pathways. Neuroendoscopic procedures enable the fenestration of cystic lesions, in addition to enabling third ventriculostomy or septostomy to restore CSF pathways. We analyze our experience regarding 77 patients affected by brain tumors arising from the wall of the third or lateral ventricle. In all cases hydrocephalus or obstruction of CSF flow was present. With an endoscopic technique, septostomy, cystostomy, endoscopic third ventriculostomy (ETV), and tumor resection were performed to control intracranial hypertension.ETV was performed in 53 patients with noncommunicating hydrocephalus. In 4 patients with low-grade astrocytoma ETV was definitely the only surgical treatment. In 12 cystic tumors, cystostomy and marsupialization into the ventricle solved a relevant mass effect with clinical intracranial hypertension syndrome. In 10 patients, neuroendoscopic relief of CSF pathways was possible by performing septostomy with the implantation of an Ommaya reservoir or one-catheter shunt. In 5 colloid cysts and 2 cystic craniopharyngiomas, removal was possible by restoring CSF flow without other procedures. After intracranial hypertension control, in 13 malignant gliomas and 5 leptomeningeal metastases, the patients' quality of life improved sufficiently to provide for tumor adjuvant therapy.In this series, endoscopy, due to its minimally invasive characteristics and reduced complications, was found to be safe and effective, without any relevant postoperative morbidity, gained by avoiding major surgical approaches.Based on these results and on the increasing number of series described in the literature, we believe that endoscopic techniques should be considered a selected approach for treating CSF obstructions caused by para-intraventricular tumors. The result of using neuroendoscopy is the reconstruction of CSF pathways that bypass the tumor occlusion. This surgical procedure is not only limited to the relief of noncommunicating hydrocephalus, but it is also useful for tumor removal or biopsies and the evacuation of cystic lesions. In patients affected by malignant tumors, neuroendoscopy can be performed to control intracranial hypertension before the patients start adjuvant chemotherapy or radiotherapy.

Comparison of Intracranial Neuroendoscopic Procedures in Children versus Adults

BACKGROUND

The emphasis regarding intracranial neuroendoscopy has been traditionally advocated and focused on the role in pediatric patients, although a significant usage has developed in adult patients. In this study, we examine and contrast the role of predominantly intracranial neuroendoscopy in both a pediatric and adult population with a minimum postprocedure follow-up of 5 years.

METHODS

A retrospective review was conducted for patients in the two hospitals that manage neurosurgical care for Southern Alberta, Canada, undergoing neuroendoscopic surgery between 1994 and 2008. The pediatric group was defined as age ≤17 years and the adult group as age ≥18 years.

RESULTS

A total of 273 patients who underwent a total of 330 procedures with a mean postprocedure follow-up of 12.9 years were identified. There were 161 adult and 112 pediatric patients, and both groups underwent surgery by the same surgeons. The most common procedure was endoscopic third ventriculostomy, accounting for 55% of procedures. One postoperative death occurred in an adult patient. Endoscopic third ventriculostomy success 1-year postprocedure was 81%, with only three late-term failures. Postoperative infection was the most common serious complication (two pediatric/four adult patients). Adult and pediatric patients had similar major complication rates (4.2% vs 5.7%, p=0.547).

CONCLUSIONS

Neuroendoscopy overall had a similar role in both pediatric and adult neurosurgical populations, with the most commonly associated complication being infection. Neuroendoscopy is an important therapeutic modality in the management of appropriate adult patients.

Initial Experience with High-Definition Camera-On-a-Chip Flexible Endoscopy for Intraventricular Neurosurgery

OBJECTIVE

The usefulness of existing neuroendoscopes has been limited by either decreased range of motion or suboptimal image resolution. The flexible high-definition chip-camera endoscope has emerged as a potential solution to the shortcomings of available instruments by combining superior flexibility and image quality in order to better operate within spatially constrained intraventricular operations.

CASE DESCRIPTION

Here we describe a 36-year-old woman who presented with hydrocephalus caused by an obstructive mass arising from the tectum. A high-definition camera-on-a-chip flexible neuroendoscope was used to sample the tectal mass after a traditional neuroendoscope was used to perform a third ventriculostomy.

CONCLUSIONS

As demonstrated by this initial experience, the use of high-definition camera-on-a-chip flexible endoscopy may provide enhanced intraoperative visualization and application for intraventricular neurosurgery.

Combined rigid and flexible endoscopy for tumors in the posterior third ventricle

OBJECT

Tumors leading to occlusion of the sylvian aqueduct include those of pineal, thalamic, and tectal origins. These tumors cause obstructive hydrocephalus and thus necessitate a CSF diversion procedure such as an endoscopic third ventriculostomy (ETV), often coupled with an endoscopic biopsy (EBX). Lesions located posterior to the massa intermedia pose a technical challenge, as the use of a rigid endoscope for performing both an ETV and EBX is limited. The authors describe their experience using a combined rigid and flexible endoscopic procedure through a single bur hole for both procedures in patients with posterior third ventricular tumors.

METHODS

Since January 2012, patients with posterior third ventricular tumors causing hydrocephalus underwent dual ETV and EBX procedures using the combined rigid-flexible endoscopic technique. Following institutional review board approval, data from clinical, radiological, surgical, and pathological records were retrospectively collected.

RESULTS

Six patients 3.5-53 years of age were included. Lesion locations included pineal (n = 3), fourth ventricle (n = 1), aqueduct (n = 1), and tectum (n = 1). The ETV and EBX were successful in all cases. Pathologies included pilocytic astrocytoma, pineoblastoma, ependymoma Grade II, germinoma, low-grade glioneural tumor, and atypical choroid plexus papilloma. One patient experienced an immediate postoperative intraventricular hemorrhage necessitating evacuation of the clots and resection of the tumor, eventually leading to the patient's death.

CONCLUSIONS

The authors recommend using a combined rigid-flexible endoscope for endoscopic third ventriculostomy and biopsy to approach posterior third ventricular tumors (behind the massa intermedia). This technique overcomes the limitations of using a rigid endoscope by reaching 2 distant regions.

Third ventricular schwannoma with hydrocephalus

Intraventricular schwannomas are rare, with only 20 cases reported in the literature to our knowledge, including two cases of schwannomas in the third ventricle. We report a 23-year-old man with a mass in the posterior portion of the third ventricle and obstructive hydrocephalus. The intraventricular mass was clearly visualized and removed by neuroendoscopic surgery, and endoscopic third ventriculostomy was simultaneously performed for the hydrocephalus. Histological and immunohistochemical assays of the surgical sample established a diagnosis of intraventricular schwannoma. The patient had a favourable outcome and no neurological deficits 1 year later. The schwannoma was distant from the choroid plexus, which supports the hypothesis that the schwannoma originated from ectopic neural crest cells that were displaced during embryogenesis.

Neuroendoscopic biopsy of brain lesions: accuracy and complications

OBJECT

The authors conducted a study to analyze the accuracy of neuroendoscopic biopsies of ventricular and periventricular lesions and record any difficulties or complications of the neuroendoscopic biopsy procedure.

METHODS

A total of 50 patients with different diseases consecutively underwent endoscopic biopsy procedures. The biopsy result was considered diagnostic if the pathologist reported any specific finding on which clinicians could base decisions about treatment or observation. The biopsy result was referred to as accurate if the results matched results of a sample obtained later or if the treatment response and disease evolution were compatible with the diagnosis. The biopsy result was considered inaccurate if results showed any relevant differences from those of the later sample or if the patient's disease did not evolve as expected. Complications were recorded and compared with those found in a literature review.

RESULTS

For 2 patients, the procedure had to be terminated. The biopsy diagnostic rate was 89.6%, and the accuracy rate was 86%. Complications associated with the procedure were 3 hemorrhages (6%), 2 infections (4%), and 1 death (2%); no reoperations were needed.

CONCLUSIONS

Endoscopic biopsy seems to be an accurate procedure with acceptable morbidity and mortality rates.