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Purpose: Endoscopic third ventriculostomy (ETV) is an effective treatment for obstructive hydrocephalus. Secondary stoma closure may be life threatening and is the most common reason for late ETV failure, mostly secondary to local scarring. Local stents intended to maintain patency are rarely used. In this study, we summarize our experience using stented ETV (sETV), efficacy, and safety., Material and Methods: Data was retrospectively collected from all consecutive patients who underwent ETV with stenting at four centers. Collected data included indications for using sETV, hydrocephalic history, surgical technique, outcomes, and complications., Results: Sixty-seven cases were included. Forty had a primary sETV, and 27 had a secondary sETV (following a prior shunt, ETV, or both). The average age during surgery was 22 years. Main indications for sETV included an adjacent tumor (n = 15), thick or redundant tuber cinereum (n = 24), and prior ETV failure (n = 16). Fifty-nine patients (88%) had a successful sETV. Eight patients failed 11 ± 8 months following surgery. Reasons for failure included obstruction of the stent, reabsorption insufficiency, and CSF leak (n = 2 each), and massive hygroma and tumor spread (n = 1 each). Complications included subdural hygroma (n = 4), CSF leak (n = 2), and stent malposition (n = 1). There were no complications associated with two stent removals., Conclusion: Stented ETV appears to be feasible and safe. It may be indicated in selected cases such as patients with prior ETV failure, or as a primary treatment in cases with anatomical alterations caused by tumors or thickened tuber cinereum. Future investigations are needed to further elucidate its role in non-communicating hydrocephalus., (© 2024. The Author(s).)

Background and Objectives: Surgery of posterior fossa meningiomas is extremely challenging even for experienced skull base surgeons because of the close proximity to cranial nerves and tight spaces. Endoscope-assisted surgery for posterior fossa meningiomas can enable a high degree of tumor resection even when using small approaches. This study describes the advantage of endoscope-assisted microneurosurgery in resection of posterior fossa skull base meningiomas and the clinical outcome., Methods: All endoscope-assisted surgeries for resection of posterior fossa meningiomas performed between 2002 and 2016 in our department were retrospectively analyzed. For data acquisition, the patient files were used. Tumor size and extent of resection were evaluated on pre- and postoperative magnetic resonance imaging. The value of endoscope assistance was assessed according to the intraoperative videos and the surgical notes. Complications and long-term outcomes were evaluated., Results: We identified 39 female and 10 male patients. The mean age of the patients at the time of surgery was 55 years, ranging from 25 to 78 years. The mean follow-up was 93.8 months. A total of 41% of the tumors were large to giant. The retrosigmoid approach was used in most patients (45). A gross total resection could be achieved in 38 patients (78%). In 11 patients (22%), a near total resection was performed. In 27 patients (55%), a hidden residual tumor, which could not been visualized with the operating microscope, was identified with the endoscope. In 6 patients (22.2%), the internal auditory canal was visualized, in 9 patients (33.3%), the Meckel's cave was visualized, and in 5 patients (18.5%), both were visualized under endoscope assistance. In 26 of those patients (96.3%), the residual tumor was resected under endoscopic view., Conclusion: Endoscope-assisted surgery for posterior fossa skull base meningiomas enables a high degree of tumor resection, avoids more invasive skull base approaches, and reduces the amount of cerebellar retraction., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Purpose: Endoscopic transaqueductal stenting has become a well-accepted treatment option for a selected small subset of aqueductal stenosis-related obstructive hydrocephalus. However, transaqueductal stenting poses unique challenges and risks which requires critical consideration. This report discusses the clinical experiences with transaqueductal stenting for periaqueductal tumor-related aqueductal stenosis focusing on pediatric patients., Methods: A retrospective analysis of all patients undergoing endoscopic TAS from 01/1993 to 01/2022 in the author's departments was performed. Demographic, clinical, radiological, and intraoperative endoscopic data were evaluated. All patients with AS-related occlusive hydrocephalus that was treated with TAS were analyzed and prospectively followed. Special attention has been given to providing insights into indications, surgical technique, and limitations., Results: Out of 28 endoscopic transaqueductal endoscopis stenting procedures, five procedures were performed on periaqueductal tumor-related obstructive hydrocephalus, two children and three adult patients. CSF pathway was obstructed by tumor located in the aqueduct in 2, by tumor in the thalamus/mesencephalon in 1, by a tumor within the third ventricle in 1, and by a tumor of the lamina tecti in 1. Simultaneously with transaqueductal stenting, 2 endoscopic third ventriculostomies (ETV), 3 tumor biopsies, and 1 tumor resection were performed. Postoperative complications included the following: CSF fistula (1 case), and asymptomatic fornix contusion (1 case). A working aqueductal stent was achieved in all cases based on clinical follow-up evaluation. Postoperatively, all patients showed improvement or resolution of their symptoms. The mean follow-up period was 25.2 months (range, 1-108 months). One patient died due to tumor progression during early follow-up. No stent migration was seen., Conclusion: Endoscopic third ventriculostomy remains the gold standard for treatment of CSF circulation obstructions with lesions in the posterior third ventricle and aqueduct. Transaqueductal stenting for periaqueductal tumor-related aqueductal compression is technically feasible. However, because of the potential high risks and subtle advantages compared with ETV transaqueductal stenting, it might be indicated in a small subset of well-selected patients if alternative treatment options are not at hand., (© 2023. The Author(s).)

Introduction: Endoscopy was first employed in the surgical treatment of neurosurgical diseases early in the twentieth century, but did not become an established practice for a long time, mainly because of poor technology and clinical results. After a slow re-appearance in the 1980s, the 1990s saw an explosion of techniques and instrumentation. Continuing technological improvement has led to further expansion of surgical techniques and indications for use of neuroendoscopy., Discussion: The expansion of ventricular endoscopy has led to significant understanding of CSF disorders. Aqueduct stenosis as cause of hydrocephalus and arachnoid cysts are an example of pathologies, the concept and understanding of which now is considerably enhanced, due to the application of neuroendoscopy in their treatment. Management of loculated hydrocephalus has been facilitated considerably with the use of the endoscope. The concepts of aqueductoplasty, septostomy, and foraminoplasty of the foramina of Monro and Magendie emerged, which were previously unknown. Skull base surgery, especially surgery for craniopharyngioma, has seen dramatic improvement in results with the use of the endoscope. Coupling of the endoscope with neuronavigation has expanded technical capabilities even further. Overall, we can do a lot more with the endoscope now in comparison to 30 years ago., Conclusion: We should always remember that the endoscope is only a tool. Its use has indications and limitations related to its design and our ability to extract the maximum, in the context of its shortcomings. Further technological advances will push surgical frontiers even more in years to come., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunting are well-established treatments of obstructive hydrocephalus (HCP) in adult and pediatric patients. However, there is a lack of data with regard to the quality of life (QoL) of these patients during long-term follow-up METHODS: Inclusion criteria were pediatric patients with endoscopic treatment of hydrocephalus at the University Medicine Greifswald between 1993 and 2016. Patients older than 14 years at present were assessed with the Short Form-12 (SF-12) questionnaire. Patients younger than 14 years of age were assessed with the KINDL-R questionnaire that was completed by their parents. Patients' values were compared with the scores of a corresponding age-matched group of the healthy population and with patients who received later shunt treatment. Information about comorbidities, current symptoms, and educational level were gained by an additional part. Comparative analysis between patients with ETV success and failure (defined as shunt implantation after ETV) was performed., Results: A total of 107 patients (53 m, 54f) were included. Fifty-seven/107 patients (53.3%) were considered as ETV success. Mean age at ETV was 6.9 ± 5.9 years. Fifty-four statements of 89 patients that are still alive were gained (response rate 63%). Of these, 49 questionnaires were complete and evaluable (23 m, 26f; mean age 19.8 ± 10.0 years with an average follow-up period of 13.7 ± 7.2 years). Twenty-six/49 patients (53.1%) are considered ETV success. No statistically significant differences could be obtained between patients with ETV success and ETV failure. Patients older 14 years show QoL within normal range, patients younger than 14 years show significantly lower result regarding their environment of peers and social contacts. Patients younger than 6 months at the time of ETV and patients with posthemorrhagic HCP show significantly lower physical QoL. Gait disturbance, fatigue, and seizures are associated with a lower QoL, and educational level is lower than in the normal population., Conclusions: Patients who underwent ETV in childhood do not have a lower health-related QoL in general. Subsequent insertions of ventriculoperitoneal (vp) shunts do not lower QoL. Certain subgroups of the patients show lower results compared to the healthy population., (© 2022. The Author(s).)

Background:  The usefulness of the endoscopic sheath is underreported in the literature., Objective and Methods:  To explain the use of an endoscopic sheath and to highlight its benefits., Results:  In addition to protecting the surrounding brain parenchyma when inserting the endoscope, the endoscopic sheath is a very useful tool to retract neurovascular structures, achieve hemostasis, and create adequate working space within narrow ventricles. The sheath can be moved within the ventricular system, and the endoscope can be moved independently within the sheath. These movements represent all the advantages of the endoscopic sheath., Conclusions:  We used an endoscopic sheath in ∼ 300 intraventricular neuroendoscopic procedures and consider the sheath an essential part of a ventriculoscopic system. Proper use of the sheath can help avoid or manage endoscopic complications., Competing Interests: None declared., (Thieme. All rights reserved.)

The endoscopic endonasal approach to suprasellar craniopharyngiomas has become popular as alternative to transcranial approaches. However, the literature lacks data regarding quality of life and olfactory function. The assessment of the long-term quality of life and olfactory function of all patients harboring a suprasellar craniopharyngioma who underwent surgery in our department has been done. Patient characteristics and perioperative data were gathered in a prospectively maintained database. At the last follow-up visit, the olfactory function and the quality of life (ASBQ, SNOT-22) as well as visual and pituitary function were assessed. Thirteen and 17 patients underwent surgery via a transcranial (T) and endonasal (E) route, respectively. No differences were seen in ASBQ, SNOT-22, and olfactory function between T and E, but in E were more full-time worker and less obesity. CSF leaks occurred in 15% of T and 29% of E (p = 0.43). Patients from group E had a superior visual outcome which was most pronounced in the visual field. The degree of new anterior and posterior pituitary gland deficiency after surgery and in the follow-up was lower in group E. The general and sinonasal quality of life and the olfactory function are equal in E and T. E is associated with a superior visual outcome, lower rates of diabetes insipidus, and lower rates of obesity, but has a higher risk for postoperative CSF leaks.

Background: Since the development of neuroendoscopy, pure endoscopic fenestration for intracranial arachnoid cysts (ACs) became more and more popular and is actually preferred by many neurosurgeons., Objective: To explore their techniques and experiences with endoscopic treatment of intracranial ACs over a 25-yr period., Methods: A total of 95 endoscopic procedures in 87 patients with 88 intracranial ACs performed at the authors' departments between February 1993 and October 2018 were retrospectively analyzed. Particular respect was given to surgical technique, complications, patients' outcome, and radiological benefit in relation to cyst location., Results: Patients' ages ranged from 23 d to 81 yr (mean: 29.9 yr). Cysts were located temporobasal (n = 31; 35.2%), paraxial supratentorial (n = 14; 15.9%), suprasellar/prepontine (n = 14; 15.9%), quadrigeminal (n = 12; 13.6%), infratentorial (n = 11; 12.5%), and supratentorial intraventricular (n = 6; 6.8%). Four different endoscopic techniques were applied: cystocisternostomies (n = 48; 50.5%), ventriculocystostomies (n = 23; 24.2%), cystoventriculostomies (n = 14; 14.7%), and ventriculocystocisternostomies (n = 10; 10.5%). Pure endoscopic technique was feasible in 89 of the 95 surgeries (93.7%). Clinical improvement was documented after 82 surgeries (86.3%) and radiological benefit after 62 surgeries (65.3%). Recurrences developed in 8 cases (8.4%). Overall complication rate was 21.1% (n = 20), postoperative new shunt dependency was observed in 4.2% of the cases (n = 4)., Conclusion: Pure endoscopic AC fenestration is a safe, effective, and less invasive technique providing high success and low permanent complication rates. The most frequent temporobasal cysts are the most difficult to treat endoscopically. A long-term follow-up is recommended because recurrences may occur many years after first treatment., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Purpose: Age and etiology play a crucial role in success of endoscopic third ventriculostomy (ETV) as a treatment of obstructive hydrocephalus. Outcome is worse in infants, and controversies still exist whether ETV is superior to shunt placement. We retrospectively analyzed 70 patients below 2 years from 4 different centers treated with ETV and assessed success., Methods: Children < 2 years who received an ETV within 1994-2018 were included. Patients were classified according to age and etiology; < 3, 4-12, and 13-24 months, etiologically; aqueductal stenosis, post-hemorrhagic-hydrocephalus (PHH), tumor-related, fourth ventricle outflow obstruction, with Chiari-type II and following CSF infection. We investigated statistically the predictors for ETV success through computing Kaplan-Meier estimates using patient's follow-up time and time to ETV failure., Results: We collected 70 patients. ETV success rate was 41.4%. The highest rate was in tumor-related hydrocephalus and fourth ventricle outlet obstruction (62.5%, 60%) and the lowest rate was in Chiari-type II and following infection (16.7%, 0%). The below 3 months age group showed relatively lower success rate (33.3%) in comparison to older groups which showed similar results (46.4%, 46.6%). Statistically, a previous VP shunt was a predictor for failure (p value < 0.05)., Conclusion: Factors suggesting a high possibility of failure were age < 3 months and etiology such as Chiari-type II or following infection. Altered CSF dynamics in patients with PHH and under-developed arachnoid villi may play a role in ETV failure. We do not recommend ETV as first line in children < 3 months of age or in case of Chiari II or following infection.

Purpose: The craniometrics of head circumference (HC) and ventricular size are part of the clinical assessment of infants with hydrocephalus and are often utilized in conjunction with other clinical and radiological parameters to determine the success of treatment. We aimed to assess the effect of endoscopic third ventriculostomy (ETV) and shunting on craniometric measurements during the follow-up of a cohort of infants with symptomatic triventricular hydrocephalus secondary to aqueductal stenosis., Methods: We performed a post hoc analysis of data from the International Infant Hydrocephalus Study (IIHS)-a prospective, multicenter study of infants (< 24 months old) with hydrocephalus from aqueductal stenosis who were treated with either an ETV or shunt. During various stages of a 5-year follow-up period, the following craniometrics were measured: HC, HC centile, HC z-score, and frontal-occipital horn ratio (FOR). Data were compared in an analysis of covariance, adjusting for baseline variables including age at surgery and sex., Results: Of 158 enrolled patients, 115 underwent an ETV, while 43 received a shunt. Both procedures led to improvements in the mean HC centile position and z-score, a trend which continued until the 5-year assessment point. A similar trend was noted for FOR which was measured at 12 months and 3 years following initial treatment. Although the values were consistently higher for ETV compared with shunt, the differences in HC value, centile, and z-score were not significant. ETV was associated with a significantly higher FOR compared with shunting at 12 months (0.52 vs 0.44; p = 0.002) and 3 years (0.46 vs 0.38; p = 0.03) of follow-up., Conclusion: ETV and shunting led to improvements in HC centile, z-score, and FOR measurements during long-term follow-up of infants with hydrocephalus secondary to aqueductal stenosis. Head size did not significantly differ between the treatment groups during follow-up, however ventricle size was greater in those undergoing ETV when measured at 1 and 3 years following treatment.

Objective: Postoperative CSF leakage is the most common unwanted sequela of transnasal pituitary surgery. The individual anatomy, the extent of the sellar opening, and the occurrence of an intraoperative CSF leak add to the risk of postoperative rhinorrhea. Despite the current sophistication and recent developments in pituitary surgery, watertight closure of the sellar floor remains a matter of concern. Improvements and additions to the technical armamentarium of sellar reconstruction are therefore still desirable., Methods: The authors present a closure technique of the sellar floor using a bioresorbable polydioxanone foil, which is placed between the dura and the bony margins of the open sellar floor to keep the intrasellar implants in place and to withstand the pressure arising from the intracranial compartment., Results: The technique was used in a technical case series of 30 patients, and in all patients the floor could be sufficiently reconstructed. CSF flow intraoperatively was documented in 10 cases (33.3%). Postoperative CSF rhinorrhea was detected in one patient (3.3%). No complications could be attributed to the technique or the material during a mean follow-up period of 477 days. The foils can easily be identified on MR images and CT scans and therefore do not affect the postoperative radiological assessment., Conclusions: The described technique is an easy, inexpensive, and reliable method for sellar floor reconstruction and has a low CSF leakage rate. It is recommended when the risk of a postoperative CSF leak is high and there is still enough bony margin of the sellar floor left that enables a sufficient fixation of the foil.

Background: During the 1990s, endoscopic aqueductoplasty (AP) was considered to be a valuable alternative to endoscopic third ventriculostomy (ETV) in treating hydrocephalus related to idiopathic aqueductal stenosis (iAS), with promising short-term outcomes., Objective: To evaluate the long-term outcome of AP in the treatment of iAS., Methods: Long-term follow-up clinical examinations and magnetic resonance (MR) imaging were performed for patients treated by an AP for iAS in our department., Results: Twenty patients (14 female, 6 male, mean age 41.7 yr, range 0.5-67 yr) were treated between 1996 and 2002. Two patients were lost to long-term follow-up. One patient died 6 mo after AP, but death was not related to the procedure. The mean follow-up for the remaining 17 patients was 120 mo. Clinically relevant aqueductal reclosure was observed in 11/17 patients after a mean follow-up of 53.4 mo. These 11 patients underwent ETV, which has been successful during further follow-up. Four of the six remaining patients presented with no clinical symptoms, although aqueductal restenosis was observed on MR imaging. Thus, the overall failure rate of AP was 88.2%. The failures were homogeneously distributed over the entire follow-up period., Conclusion: AP has a high risk of failure during long-term follow-up and is not recommended as the first choice of treatment in hydrocephalus caused by iAS. ETV should be done instead. AP may be reserved for a limited number of patients in whom ETV is not feasible but should be combined with stenting to avoid reclosure of the aqueduct., (Copyright © 2018 by the Congress of Neurological Surgeons.)

Background: Endoscopic resection of colloid cysts is a widely accepted treatment option instead of microsurgery. However, there is still a debate about a potentially higher rate of incomplete resections and recurrence., Objective: The aim of this retrospective study was to evaluate long-term results after endoscopic removal of colloid cysts., Methods: Twenty patients underwent endoscopic treatment in our department. Eighteen patients agreed to follow-up examinations. In 17 patients, magnetic resonance images were obtained., Results: Total cyst resection was achieved in 16 procedures. In 1 patient, only plexus coagulation and widening of the ipsilateral foramen of Monro were performed. In 3 patients, small remnants of the cyst membrane were left behind. Conversion to microsurgery became necessary in 1 patient. Mild temporary complications occurred in 6 patients. Preoperative symptoms were completely relieved in 16 patients and improved in 2 patients. The average follow-up period was 188 months. In the patient with plexus coagulation, the cyst did not change. Recurrence occurred in 2 of 3 patients with cyst remnants. To date, no cyst remnant or recurrence has caused any symptoms or required surgical treatment., Conclusions: Our results indicate that endoscopic treatment of colloid cysts is a safe and effective treatment option that provides excellent long-term results. However, we determined that a significant risk for recurrence exists when even small parts of the cyst capsule were left behind. Therefore, we advocate an attempt at total endoscopic cyst resection., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: The unexpected intraoperative intraventricular hemorrhage is a rare but feared and life-threatening complication in neuroendoscopic procedures because of loss of endoscopic vision. The authors present their experience with the so-called "dry field technique" (DFT) for the management of intraventricular hemorrhages during purely endoscopic procedures. This technique requires the aspiration of the entire intraventricular CSF to achieve clear visualization of the bleeding source., Methods: More than 500 neuroendoscopic intraventricular procedures were retrospectively analyzed over the last 24 years for documented severe hemorrhages, which were treated by the application of the DFT., Results: The technique was required in 6 cases, including tumor resection/biopsy, cyst resection, and intraventricular lavage. Additionally, the technique was applied as part of the planned strategy in 3 cases of endoscopic tumor removal. The hemorrhage was stopped in all cases and no associated postoperative deficits occurred., Conclusions: Although severe hemorrhages are rare, the neurosurgeon needs to be aware of them and has to establish strategies for their management. Most hemorrhages can be stopped by constant irrigation and coagulation. In the other rare cases, the DFT is a safe, reliable technique and can be easily incorporated into endoscopic surgery.

OBJECTIVE In tuberculum sellae meningioma (TSM) surgery, endonasal approaches are claimed to have a superior visual outcome compared with transcranial approaches. The authors question whether this is always true and analyze their series of cases of endoscope-assisted transcranial TSM surgery with special regard to the postoperative visual outcome in order to explore this issue. METHODS All surgical procedures for TSM performed between 2003 and 2015 in the Department of Neurosurgery, University Medicine Greifswald, were retrospectively analyzed. Special attention was paid to the postoperative visual outcome. RESULTS During the study period, 15 patients (12 female and 3 male) underwent surgery for TSM. Gross-total resection was achieved in 14 cases (93.3%) and near-total resection in 1. One patient suffered from a major stroke during surgery and had to be excluded from further analyses. No other complications occurred. Preoperatively, visual acuity was disturbed in 12 patients (80%) and visual field deficits were present in 11 patients (73.3%). In 3 patients (20%), the TSM was an incidental finding. Postoperatively, ophthalmological examination revealed an improvement of visual acuity in 10 (90.9%) of 11 patients and improvement of visual field deficits in 9 (90%) of 10 patients; no deterioration of visual acuity or visual field was seen in any patient. Visual acuity and visual field improvement was observed in all patients who had surgery within 3 years after the onset of visual disturbances. No tumor recurrence was observed during follow-up (mean 32 months, range 3-134 months). TSMs were approached via a frontolateral craniotomy in 7 patients and via a supraorbital craniotomy in 8. The use of the endoscope as an assistive device led to improved tumor visualization and consequent removal in areas that were hidden in the microscopic view in 6 patients (40%). CONCLUSIONS The present series confirms a favorable visual outcome after TSM surgery via supraorbital or frontolateral endoscope-assisted approaches. With endoscopic visualization, major manipulation of the optic apparatus could be avoided, perhaps affecting the favorable visual outcome.

Background: Intraparenchymal cysts without communication to the ventricles or the subarachnoid space are named ependymal or epithelial cysts. The estimated ratio of their incidence compared with arachnoid cysts is 1:10. Neurologic deficit can occur when the cyst exerts mass effect on its surroundings. We evaluated the success rate of endoscopic fenestration of intracranial ependymal cysts., Methods: Our prospectively maintained endoscopy database was screened for all cases of ependymal cysts. The charts were retrospectively reviewed for symptoms, surgery, postoperative course, and complications. Magnetic resonance imaging scans performed before and after surgery were analyzed., Results: We identified 6 patients harboring an intracranial ependymal cyst. The cyst location was frontoparietal, parietal, occipital, or mesencephalic. Patients presented with several symptoms according to the location of the cyst (i.e., epilepsy, hemiparesis, diplopia, hemianopsia). All patients were treated by navigation-guided endoscopic fenestration of the cyst to the ventricular system. Two complications occurred: a cerebrospinal fluid leak, which was managed surgically by wound revision without the need for cerebrospinal fluid shunting, and a chronic subdural hematoma, which occurred 6 weeks after surgery and required burr hole evacuation. Follow-up period ranged from 6 months to 9 years. Magnetic resonance imaging revealed that all cysts decreased in size. Symptoms improved in all patients., Conclusions: Endoscopic fenestration of ependymal cysts to an adjacent ventricular cavity is a treatment option with excellent long-term results and minimal morbidity. It should be considered as the therapy of choice to avoid craniotomy and shunt dependence., (Copyright © 2016 Elsevier Inc. All rights reserved.)

OBJECTIVE Since its revival in the early 1990s, neuroendoscopy has become an integral component of modern neurosurgery. Endoscopic stent placement for treatment of CSF pathway obstruction is a rarely used and underestimated procedure. The authors present the first series of neuroendoscopic intracranial stenting for CSF pathway obstruction in adults with associated results and complications spanning a long-term follow-up of 20 years. METHODS The authors retrospectively reviewed a prospectively maintained clinical database for endoscopic stent placement performed in adults between 1993 and 2013. RESULTS Of 526 endoscopic intraventricular procedures, stents were placed for treatment of CSF disorders in 25 cases (4.8%). The technique was used in the management of arachnoid cysts (ACs; n = 8), tumor-related CSF disorders (n = 13), and hydrocephalus due to stenosis of the foramen of Monro (n = 2) or aqueduct (n = 2). The mean follow-up was 87.1 months. No deaths or infections occurred that were related to endoscopic placement of intracranial stents. Late stent dislocation or migration was observed in 3 patients (12%). CONCLUSIONS Endoscopic intracranial stent placement in adults is rarely required but is a safe and helpful technique in select cases. It is indicated when reliable and long-lasting restoration of CSF pathway obstructions cannot be achieved with standard endoscopic techniques. In the treatment of tumor-related hydrocephalus, it is a good option to avoid reclosure of the restored CSF pathway by tumor growth. Currently, routine stent placement after endoscopic fenestration of ACs is not recommended. Stent placement for treatment of CSF disorders due to tumor is a good option for avoiding CSF shunting. To avoid stent migration and dislocation, and to allow for easy removal if needed, the device should be fixed to a bur hole reservoir.

The endoscopic endonasal approach for craniopharyngiomas is increasingly used as an alternative to microsurgical transsphenoidal or transcranial approaches. It is a step forward in treatment, providing improved resection rates and better visual outcome. Especially in retrochiasmatic tumors, this approach provides better lesion access and reduces the degree of manipulations of the optic apparatus. The panoramic view offered by endoscopy and the use of angulated optics allows the removal of lesions extending far into the third ventricle avoiding microsurgical brain splitting. Intensive training is required to perform this surgery. This article summarizes the surgical technique, outcome, and complications., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Acute intraoperative intraventricular hemorrhage is a feared event in endoscopic neurosurgical procedures., Objective: To describe the small-chamber irrigation technique (SCIT) for intraoperative endoscopic management of intraventricular hemorrhage., Methods: The SCIT was used in intraventricular surgery for hydrocephalus, intraventricular tumors requiring biopsy, arachnoid cysts, and colloid cysts., Results: Intraventricular hemorrhage was successfully managed endoscopically with a combination of the SCIT, routine irrigation, and coagulation, allowing for completion of the primary procedures., Conclusion: The SCIT is a powerful tool that the neuroendoscopist can use for visualization to achieve hemostasis when performing intraventricular endoscopic surgery.

This article describes a new endoscopic cutting tool that acts like a guillotine. It enables safe cutting of membranes overlying neurovascular structures because the footplate protects these structures from inadvertent injury. The footplate is introduced under the membrane, elevating it slightly, and then the membrane is cut while pushing the blade down into the footplate. The guillotine knife has been used in various endoscopic procedures such as septostomies, arachnoid cyst fenestrations, colloid cysts resections, and fenestrations of other intraventricular membranes. The authors think that the guillotine knife is a useful addition to the neuroendoscopic armamentarium.

Purpose: Although successful endoscopic third ventriculostomy (ETV) has been reported for many indications, peculiarities of the surgical technique in each separate indication require particular respect., Methods: A detailed account of the authors' surgical technique, their presurgical considerations, and their intraoperative strategies to perform ETV is presented. Surgery of representative obstructive hydrocephalus cases in posterior fossa lesions (cerebellar infarction, posterior fossa tumor), in distortion of the ventricular system (intracranial hemorrhage, basilar artery aneurysm) and in membranous obstruction (aqueductal stenosis, posterior fossa malformation), is illustrated in detail., Results: In posterior fossa lesions, careful evaluation of the prepontine space and localization of the basilar artery is mandatory. Recognition of mammillary bodies and infundibular recess is of particular importance since the third ventricle floor is rather thick and nontranslucent. In distortion of the ventricular system, careful analysis of the preoperative imaging allows the selection of the optimal approach. Sometimes, blood clot removal and vigorous irrigation is required. Frequently, the landmarks are difficult to identify. These are cases for experienced endoscopic neurosurgeons. In aqueductal stenosis and posterior fossa malformation, perforation of the often thin and translucent ventricular floor is easy because of clear anatomical landmarks. Those are ideal candidates for ETV. For experienced neuroendoscopists, the authors advocate inspection of the fourth ventricle with a flexible scope to ensure cerebrospinal fluid (CSF) circulation obstruction., Conclusions: ETV is a frequent and well-established endoscopic technique. Based on the underlying pathology, the technique has to be modified to obtain good results with minimal complications., (Georg Thieme Verlag KG Stuttgart · New York.)

Background: During the past decade, endoscopic intraventricular and skull base operations have become widely used for a variety of evolving indications. A global survey of practicing endoscopic neurosurgeons was performed to characterize patterns of usage regarding endoscopy equipment, instrumentation, and the indications for using image-guided surgery systems (IGSs)., Methods: An online survey consisting of 8 questions was completed by 235 neurosurgeons with endoscopic surgical experience. Responses were entered into a database and subsequently analyzed., Results: The median number of operations performed per year by intraventricular and skull base endoscopic surgeons was 27 and 25, respectively. Data regarding endoscopic equipment brand, diameter, and length are presented. The most commonly reported indications for IGSs during intraventricular endoscopic surgery were tumor biopsy/resection, intraventricular cyst fenestration, septostomy/pellucidotomy, endoscopic third ventriculostomy, and aqueductal stent placement. Intraventricular surgeons reported using IGSs for all cases in 16.6% and never in 24.4%. Overall, endoscopic skull base surgeons reported using IGSs for all cases in 23.9% and never in 18.9%. The most commonly reported indications for IGSs during endoscopic skull base operations were complex sinus/skull base anatomy, extended approaches, and reoperation., Conclusions: Many variations and permutations for performing intraventricular and skull base endoscopic surgery exist worldwide. Much can be learned by studying the patterns and indications for using various types of equipment and operative adjuncts such as IGSs., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Entrapment of the temporal horn is a rare form of isolated hydrocephalus. Standard treatment has not yet been established for this condition, and only a few cases have been reported in the literature. The authors reviewed their prospectively maintained database to report their experience with endoscopic temporal ventriculocisternostomy. All endoscopic operations performed in the Department of Neurosurgery at Ernst Moritz Arndt University between March 1993 and August 2012 were reviewed, and a retrospective chart review of all patients with temporal ventriculocisternostomy was performed. Four patients were identified (3 children and 1 adult). In 3 patients, the condition developed after tumor resection, and in 1 patient it developed due to postmeningitic multiloculated hydrocephalus. In 2 patients, a recurrent trapped temporal horn developed. Refenestration was successful in one of these patients, and dilation in the trigone area with a subsequent stomy of the septum pellucidum was successful in the other. In 1 patient, postoperative meningitis developed, which was treated with antibiotics. Endoscopic temporal ventriculocisternostomy is an option in the treatment of trapped temporal horns. However, more experience is required to recommend it as the treatment of choice.

Objective: To describe the history of neuroendoscopy through the history of the major neurosurgeons who worked and published in the field., Methods: All relevant data described in publications before 1980 about the history of neuroendoscopy and found through OVID MEDLINE searches and related references are reported., Results: Contributions of 14 neurosurgeons who were pioneers in neuroendoscopy are described in chronologic order: Lespinasse, Dandy, Payr, Mixter, Fay, Grant, Volkmann, Putnam, Dereymacker, Scarff, Feld, Guiot, Fukushima, and Griffith., Conclusions: An historical review of ventricular neuroendoscopy remains by essence incomplete. Medical technical progress proceeds by leaps and bounds, related to the ingenuity of surgeons able to understand rapidly the value of a technical change to improve their surgical procedure. The ability to remain attentive to patients and evolving pathologies as well as the evolution of modern technology is required to make further progress in neuroendoscopy., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: To describe the neuroendoscopic technique to deal with intraventricular tumors., Methods: Details of the endoscopic approach to intraventricular tumors of the lateral, third, and fourth ventricle are presented., Results: Intraventricular tumors are ideal indications for neuroendoscopic surgery. They often cause cerebrospinal fluid (CSF) pathway obstruction, resulting in ventricular dilation, which provides sufficient space for maneuvering with the endoscope. The general principle of the endoscopic removal of intraventricular tumors is interruption of the blood supply to the tumor and subsequent tumor debulking. In general, a piecemeal resection is performed; however, in some tumors, it is possible to detach the lesion from the surrounding brain tissue and remove it in toto. In unilateral hydrocephalus caused by obstruction of one foramen of Monro, the burr hole is placed more laterally to get good access to the foramen for biopsy and to the septum for septostomy. When the tumor arises in the anterior part of the third ventricle, the burr hole is made at the coronal suture. When the tumor is located in the posterior part, the entry point is selected more anteriorly in order to pass the foramen of Monro in a straight line. In pineal region tumors, which cause occlusive hydrocephalus due to aqueductal compression, third ventriculostomy as well as tumor biopsy are required., Conclusion: Intraventricular tumors and related CSF pathway obstructions can be safely and effectively treated with endoscopic techniques. Small tumors may be totally removed via a ventriculoscope., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: To term and describe neuroendoscopic techniques., Methods: A classification into three major groups of endoscopic techniques is presented., Results: 1) Endoscopic neurosurgery ("channel" endoscopy) is mainly used in ventricular endoscopy. The surgical instruments are introduced via working channels that are located within the endoscope. 2) Endoscope-controlled microneurosurgery means that the endoscope is the only visualization tool and microsurgical instruments are used along the endoscope. Major applications are endonasal endoscopic skull base surgery, endoport surgery, and endoscopic transcranial surgery. 3) Endoscope-assisted microneurosurgery means that the microscope and the endoscope are used in the same surgery. The endoscopes are applied when hidden structures to be inspected are not visible in straight line with the microscope., Conclusions: Endoscopic techniques are a valuable addition to the neurosurgeon's armamentarium. Endoscopes are especially beneficial in deep and narrow surgical approaches and when "looking around a corner" is required., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Occlusion of both foramina of Monro following third ventriculostomy is a very rare complication. The authors present the case of a 30-year-old female who underwent endoscopic third ventriculostomy (ETV) for occlusive hydrocephalus due to aqueductal stenosis. Thirty months after the ETV, she reported recurrent headaches. Magnetic resonance imaging demonstrated bilateral enlargement of the lateral ventricles with a collapsed third ventricle caused by bilateral stenosis of the foramina of Monro. Left-sided endoscopic foraminoplasty and stenting of the left foramen of Monro were performed with immediate neurological improvement.

Object: Endoscopic third ventriculostomy (ETV) has become a well-accepted option for obstructive hydrocephalus. However, standard ventriculostomy at the floor of the third ventricle might not be feasible under certain conditions. Here, the authors report in detail on their initial experience with an alternative option of endoscopic ventriculostomy through the lamina terminalis via a transventricular route., Methods: Endoscopic third ventriculostomy through the lamina terminalis from a transventricular transforaminal route was evaluated in 4 cadaveric human heads and in 4 clinical cases., Results: In all 4 human cadavers, an opening of the lamina terminalis via a transventricular approach could be achieved without injury to either the optic chiasm or the anterior cerebral arteries. In the 4 clinical cases, an accurate and reliable ventriculostomy was performed at the lamina terminalis. The bur hole was placed directly at the coronal suture 2 cm lateral from the midline. After identifying the optic chiasm and the anterior cerebral arteries, a blunt perforation was made just anterior to the optic chiasm by using perforation forceps and a balloon catheter. After the opening, the stoma was inspected with a 0° and 30° rod lens endoscope, and its patency as well as the preservation of vessels and optic nerves was checked. No complications occurred, although all patients suffered from a clinically silent fornical contusion at the foramen of Monro., Conclusions: Endoscopic opening of the lamina terminalis via a transventricular transforaminal route appears to be feasible. No complications were observed. Although no conclusions on the clinical success rate can be drawn, the reliable anatomical opening and known success rate for anterior subfrontal approaches suggest that the technique represents an alternative in a small subgroup of patients in whom a standard ETV cannot be performed.

Object Endoscopic third ventriculostomy (ETV) is well accepted for obstructive hydrocephalus of various etiologies. Nevertheless, it is seldom considered in intracranial hemorrhage even in cases involving obstruction of the CSF circulation. Methods Between May 1993 and April 2008, 34 endoscopic procedures were performed for hemorrhage-related obstructive hydrocephalus with an intraventricular component. All patients were prospectively followed up. Special attention was paid to presurgical clinical status, type of hemorrhage, type of surgery, postsurgical clinical status, postsurgical ventricular size, and necessity of ventriculoperitoneal shunt implantation. Results An ETV was performed for treatment of obstructive hydrocephalus due to intracranial hemorrhage in 34 patients (15 male, 19 female; mean age 60.8 years [range 3 months-83 years]). Hydrocephalus was caused by 17 cerebellar, 6 thalamic, 5 intraventricular, 3 basal ganglia, 2 subarachnoid, and 1 pontine hemorrhage. Thirty-three patients (97.1%) presented with impaired consciousness. Intraventricular blood was present in all cases. In 16 cases (47.1%), blood clots had to be evacuated to achieve access to the third ventricle floor. The mean operation time was 58.2 minutes (range 25-120 minutes). Three complications occurred (rate of 8.8%) with 2 being asymptomatic (5.9%) and 1 being transient (2.9%). There was no procedure-related permanent morbidity, and no procedure-related mortality. After surgery, there was clinical improvement in 17 cases (50.0%) and radiological evidence of improvement in 22 cases (64.7%). Two patients required postoperative ventriculoperitoneal shunting (5.9%). Seven patients died of hemorrhage while in the hospital (20.6%), and another 4 died during follow-up (11.8%). Fifteen patients (44.1%) showed a persistent clinical improvement at the final follow-up (mean 12.2 months after surgery). Conclusions Endoscopic third ventriculostomy represents a safe treatment option in intraventricular hemorrhage-related obstructive hydrocephalus yielding similar results as an external drainage but with less risk of infection and a very low subsequent shunt placement rate. In cases with a predominant obstructive component, ETV should be considered in hydrocephalus due to intracerebral hemorrhage. However, performing an ETV with a blurred field of vision and distorted ventricular anatomy is a challenge for any endoscopic neurosurgeon and should be reserved for experienced neuroendoscopists.

Object: The optimal therapy of arachnoid cysts is controversial. In symptomatic extraventricular arachnoid cysts, fenestration into the basal cisterns is the gold standard. If this is not feasible, shunt placement is frequently performed although another endoscopic option is available., Methods: Between March 1997 and June 2006, 12 endoscopic cystoventriculostomies were performed for the treatment of arachnoid cysts in 11 patients (4 male and 7 female patients, mean age 52 years [range 14-71 years]). All patients were prospectively followed up., Results: In 11 cases, the arachnoid cysts were frontotemporoparietal and fenestration was performed into the lateral ventricle. In 1 case, the arachnoid cyst was located in the cerebellum and the cyst was fenestrated into the fourth ventricle. Neuronavigational guidance was used in all but 1 case. Endoscopic cystoventriculostomy was performed in all cases without complications. No stents were placed. The mean surgical time was 71 minutes (range 30-110 minutes). The mean follow-up period was 42.7 months (range 19-96 months) per surgical case and 48.8 months (range 19-127 months) per patient. Symptoms improved after 11 of the 12 procedures; 7 of the 11 patients became symptom-free and the others had only mild residual symptoms. The patient who did not experience clinical improvement suffered from depression and demonstrated a significant decrease of the cyst size on the postoperative MR imaging. After 11 of 12 procedures, a decrease in cyst size was observed. In 1 case, a subdural hematoma developed; it required surgical treatment 3 months after surgery. In another case, reclosure of the stoma required repeated endoscopic cystoventriculostomy more than 7 years after the initial procedure., Conclusions: Overall, endoscopic cystoventriculostomy represents a useful treatment option for patients with paraxial arachnoid cysts in whom a standard cystocisternotomy is not feasible. Based on the results in this case series, stent placement appears not to be required. Despite the long mean follow-up of almost 4 years, however, a longer follow-up period seems to be required before definite conclusions can be drawn.

Object: There are frequent applications for endoscopy in neurosurgery. However, endoscopic surgery in children has peculiar characteristics and is associated with different rates of success. In this study, the authors report on their experience with 134 consecutive endoscopy procedures performed in 126 patients<18 years of age., Methods: Between April 1993 and October 2007, 134 endoscopic procedures were performed in 126 children. Indications for surgery included brain tumors in 48 children, cystic lesions in 24, aqueductal stenosis in 23, various malformations in 20, hemorrhage and infarction in 6, and isolated ventricles in 5 children. In this long-term followup study, data were analyzed with respect to clinical and radiological success rates, as well as shunt dependence both in relation to lesion origin, and to the type of endoscopic procedure performed (endoscopic third ventriculostomy [ETV], septostomy, aqueductoplasty, or cystocisternostomy). Finally, the influence of patient age on the success rate was evaluated., Results: In 114 patients, restoration of CSF circulation was the goal of endoscopy, but in 2 patients only ventriculoscopy was performed followed by ventriculoperitoneal shunt placement. In 12 of 114 patients, tumor biopsy sampling or resection was performed simultaneously with shunt placement. In another 12 patients, only endoscopic tumor resection without CSF circulation restoration was done. The follow-up period ranged from 1 to 6 years. Thirteen tumor biopsies, 7 partial tumor resections, and 4 endoscopically complete tumor resections were performed. An intraoperative switch to microsurgery was made in 2 patients because of recurrent hemorrhage and an overly time-consuming endoscopic surgery. Cerebrospinal fluid circulation was successfully restored in 81 (72%) of 112 patients, with the use of endoscopy in the setting of tumor-related hydrocephalus providing the best results (86% success rate). However, of the various endoscopic procedures, cyst openings (cystocisternostomy, cystoventriculostomy, and ventriculocystocisternostomy) provided the best results-superior even to ETV-with a success rate of 77% and no complications. In contrast, endoscopic aqueductoplasty had a high failure and complication rate. Patients<6 months old who underwent ETV, septostomy, or aqueductoplasty had poor results and became more frequently shunt dependent than older children., Conclusions: Overall, endoscopy can be considered safe and effective in children. Based on the authors' data, acute hydrocephalus cases such as those caused by tumors are the best candidates for endoscopic CSF flow restoration. Interestingly, cyst openings to the ventricles or cisterns were the most successful endoscopic techniques with the lowest complication rate. Aqueductoplasty should be reserved for selected cases. Finally, the success rate of endoscopic techniques remains poor in infants<6 months of age; this was not only true of ETV, but also other techniques such as septostomy and aqueductoplasty.

We present an overview of the history, development, technological advancements, current application, and future trends of cranial endoscopy. Neuroendoscopy provides a safe and effective management modality for the treatment of a variety of intracranial disorders, either tumoral or non-tumoral, congenital, developmental, and degenerative, and its knowledge, indications, and limits are fundamental for the armamentarium of the modern neurosurgeon.

Introduction: Endoscopic third ventriculostomy (ETV) for the treatment of hydrocephalus of different etiologies is still controversial in children younger than 2 years of age. The success rate of ETV in this group of patients is analyzed in this study., Materials and Methods: The series consisted of 21 patients treated with ETV. The mean age of the patients was 6.7 months, ranging from 9 days to 15 months (16 patients were younger than 1 year). The study included hydrocephalus due to idiopathic aqueductal stenosis (eight) and other congenital anomalies (four) as well as posthemorrhagic (three) and tumor-related occlusive hydrocephalus (three). Two patients presented with shunt infection and one with a shunt failure. ETV was considered to be successful when shunting could be avoided., Results: ETV was successful in nine patients, with a mean follow-up period of 26.2 months. The procedure was successful in four patients with idiopathic aqueductal stenosis, in two with other congenital anomalies, in one posthemorrhagic, and in two with a tumor-related hydrocephalus. In 12 patients, the ETV was unsuccessful after a mean follow-up of 3.3 months. These patients required a shunt. Ten of them were less than 1 year old when ETV was performed. In one tumor-related hydrocephalus, a shunt was inserted after a meningitis after tumor removal., Conclusions: The success of ETV in children younger than 2 years of age suffering from non-communicating hydrocephalus seems to be dependent on both age and etiology. Our results show an overall success rate of 43%. In 37.5% of the children younger than 1 year of age, ETV was successful. ETV in patients with hydrocephalus due to idiopathic aqueductal stenosis seems to be more beneficial than in other causes of hydrocephalus.

Objective: This article describes our endoscopic techniques developed for the treatment of various obstructions of cerebrospinal fluid pathways., Methods: Blocked cerebrospinal fluid pathways result in ventricular dilation in front of the obstruction, which may cause acute or chronic symptoms of hydrocephalus. The traditional treatment is insertion of a shunt. Because of the high failure rate in the long term, shunts should be avoided whenever possible., Results: Our techniques of septum pellucidum fenestration, third ventriculostomy, lamina terminalis fenestration, temporal ventriculostomy, foraminoplasty of the foramen of Monro, aqueductoplasty, aqueductal stenting, and retrograde aqueductoplasty for trapped fourth ventricle are presented., Conclusion: Neuroendoscopic techniques can effectively treat obstructive hydrocephalus by restoration of the obstructed cerebrospinal fluid pathway or creating a bypass into the ventricles or subarachnoid spaces.

Objective: The surgical management of occlusive hydrocephalus caused by massive cerebellar infarction remains controversial. The procedures that are more commonly used to avoid progressive neurological deterioration are based on transient external ventricular drainage or the placement of permanent shunt systems. To our knowledge, this is the first report regarding using endoscopic third ventriculostomy (ETV) in patients with an occlusive hydrocephalus caused by cerebellar ischemic stroke. We report our experience of 10 reviewed cases., Methods: Between 1997 and 2004, 10 patients with a resulting hydrocephalus caused by a space-occupying cerebellar infarction were managed with ETV. Glasgow Coma Scale score on admission, cause of stroke, and computed tomographic signs, including the ischemic vascular territory involved and brain edema, were noted. Clinical outcome was evaluated using the Glasgow Outcome Scale., Results: In all patients, there was a mean interval of 4 days from the onset of deterioration of consciousness to operation. Mean Glasgow Coma Scale score on admission was 11.2. In nine patients, ETV was the initial procedure of ventricular drainage. One patient was primarily treated with an external ventricular drainage, but the device dislocated and ETV was performed. In one patient, an external ventricular drainage became necessary 7 days after the initial ETV because of a malfunction of the stoma. One patient showed a progressive brain edema 2 days after ETV, and suboccipital decompression was performed. Eight successfully treated patients demonstrated an improvement in the level of consciousness after ETV. Mean Glasgow Outcome Scale score on discharge of all patients was 3.4., Conclusion: Occlusive hydrocephalus caused by cerebellar infarction is infrequent. When occlusive hydrocephalus is observed, ETV can be used successfully with minimal risks, especially with avoidance of a higher rate of infectious complications caused by external drainage systems.

Objective: This study was undertaken to determine the complication rate in intracranial endoscopic neurosurgery., Results: The complications in our series of endoscopic intracranial procedures for the treatment of hydrocephalus, colloid and arachnoid cysts, as well as intraventricular tumors, were analyzed., Conclusion: Although the complication rate in endoscopic neurosurgery is low, severe, rarely even life-threatening, complications may occur. The complication rate decreases markedly with surgical experience, indicating a steep learning curve.

Object: Epidermoid tumors located in the cerebellopontine angle (CPA) are challenging lesions because they grow along the subarachnoid spaces around delicate neurovascular structures and often extend into the middle cranial fossa. The purpose of this study was to determine the value of endoscopic assistance in the microsurgical resection of these lesions, in which total removal is the therapy of choice., Methods: Eight patients harboring an epidermoid tumor of the CPA were treated using an endoscope-assisted microsurgical technique. A retrosigmoid suboccipital approach was used in five patients and a pterional transsylvian approach was chosen in the other three. In four patients the lesion was resected microsurgically and the endoscope was used repeatedly to verify complete tumor removal, whereas most of the tumor mass was removed with the aid of an operating microscope in the other four. Tumor parts extending into other cranial compartments that were not visible through the microscope were removed under endoscopic view by using rigid rod-lens scopes with 30 and 70 degrees angles of view. All epidermoids were completely evacuated and the membranes were widely resected. Large tumors occupying both the middle and posterior cranial fossa were removed through a single small opening without enlarging the craniotomy. Permanent hearing loss and permanent hypacusis were observed in one patient each. One patient with facial and one with abducent nerve palsy recovered within 6 and 4 months, respectively. A transient weakness of the chewing muscles was encountered in one patient. Postoperative magnetic resonance imaging revealed no residual tumor in any patient. To date no recurrences have been-observed (follow up range 12-98 months)., Conclusions: The endoscope-assisted microsurgical technique enables safe removal even when tumor parts are not visible in a straight line. Tumor extensions into adjacent cranial compartments can be removed with the same approach without retracting neurovascular structures or enlarging the craniotomy.

Pineal cysts are typically detected in around 1.3% to 4.3% of patients during routine magnetic resonance imaging (MRI) scans. 1,2 The vast majority of pineal cysts are benign, asymptomatic, and typically do not necessitate surgical intervention. Large pineal cysts are known to cause hydrocephalus with its associated symptoms and thus can require in rare cases surgical resection. Even in the absence of hydrocephalus, selected patients with large pineal cysts causing headaches and visual disturbances can find relief after surgical resection. 3,4 The supracerebellar infratentorial (SCIT) approach is widely used and represents an extraparenchymatous approach through a natural corridor to the pineal region. 5 Performing this approach in a semisitting position allows for an optimal retraction of the cerebellum by gravity. We employ a minimally invasive paramedian SCIT approach for the resection of pineal cysts. In our experience, the paramedian SCIT approach allows for a less steep operating angle and a smaller craniotomy compared with the midline SCIT approach. We present a 24-year-old female complaining of headache. The initial MRI was conducted 2 years before surgery. Following the initial evaluation, the patient experienced progressive headaches without neurologic deficits. A subsequent MRI revealed enlargement of the pineal cyst, leading to the indication for surgical resection. The surgery was performed mainly under the operating microscope with endoscopic visualization in suitable situations as our small approach restricts bimanual dissection with an endoscope. In our experience, this approach provides a versatile and minimally invasive access to the pineal region, making it optimally suitable for pineal cysts requiring surgical resection. [ABSTRACT FROM AUTHOR]

Objective Increasing experience with intraventricular neuroendoscopic procedures shows good results in the combination of endoscopic third ventriculostomy (ETV) and tumor biopsy. Other possible combinations are mainly presented in subgroups in the literature. Here, we present our experience with combined intraventricular procedures within 1 setting over the last 2 decades. Methods This study retrospectively analyzes data from neuroendoscopic intraventricular procedures between 1993 and 2015 in 3 different departments of neurosurgery. Inclusion criteria were a combination of at least 2 intraventricular endoscopic procedures (e.g. third ventriculostomy, cyst fenestration, tumor surgery or aqueductoplasty) within 1 setting. Results One-hundred and thirty cases with more than 300 procedures fulfilled the inclusion criteria. The most frequent combinations were ETV and tumor biopsy ( n = 36), ETV and aqueductoplasty/stenting ( n = 30), and ETV and cyst fenestration ( n = 18). The complication rate was 16.9% with an overall morbidity of 1.6% and mortality of 0.8%. Fornix contusion was one of the most frequent intraoperative complications (16.4%). Shunt independency was achieved in 82.9% of cases with hydrocephalic symptoms. Conclusions A combination of different intraventricular endoscopic procedures is safe and reliable, bearing similar risks of morbidities and mortality to single neuroendoscopic procedures. This study is one of the largest series in the literature and has similar low complication rates to others. Fornix contusion is the most frequent intraoperative complication in these patients. However, obvious clinical correlation is rare. [ABSTRACT FROM AUTHOR]