Transorbital neuroendoscopic surgery for treatment of sphenoid wing meningiomas extending to the cavernous sinus: clinical implications and a technical illustration.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of transorbital neuroendoscopic surgery (TONES) in the management of sphenoid wing meningiomas (SWMs) with cavernous sinus and orbital invasion. METHODS: The authors conducted a retrospective review of 32 patients with SWMs treated at Gazi University using TONES from October 2019 to May 2023. The study includes clinical applications to elucidate the endoscopic transorbital approach. Surgical techniques focused on safe subtotal resection, aiming to minimize residual tumor volume for subsequent radiosurgery. Data were collected on patient demographics, tumor characteristics, surgical procedures, complications, and postoperative outcomes, including radiological imaging and ophthalmological evaluations. RESULTS: Surgical dissections delineated a three-phase endoscopic transorbital approach: extraorbital, intraorbital, and intracranial. In the clinical application, gross-total resection was not achieved in any patient because of planned postoperative Gamma Knife radiosurgery. The mean follow-up period was 16.3 months. Of 30 patients with preoperative proptosis, 25 experienced postoperative improvement. No new-onset extraocular muscle paresis or visual loss occurred postoperatively. The average hospital stay was 1.15 days, with minimal complications and no significant morbidity or mortality. CONCLUSIONS: Total resection of SWMs invading the cavernous sinus and orbit is associated with substantial risks, particularly cranial nerve deficits. TONES offers a minimally invasive alternative, reducing morbidity compared with transcranial approaches, and represents a significant advancement in the surgical management of SWMs, especially those extending into the cavernous sinus and orbit. The approach provides a safe, effective, and patient-centric approach, prioritizing subtotal resection to minimize neurological deficits while preparing patients for adjunctive radiosurgery. This study positions TONES as a transformative surgical technique, aligning therapeutic efficacy with neurovascular preservation and postoperative recovery.

Open-door extended endoscopic transorbital technique to the paramedian anterior and middle cranial fossae: technical notes, anatomomorphometric quantitative analysis, and illustrative case.

OBJECTIVE: The superior eyelid endoscopic transorbital approach (SETOA) provides a direct and short minimally invasive route to the anterior and middle skull base. Nevertheless, it uses a narrow corridor that limits its angles of attack. The aim of this study was to evaluate the feasibility and potential benefits of an "extended" conservative variant of the "standard" endoscopic transorbital approach-termed "open-door"-to enhance the exposure of lesions affecting the paramedian aspect of the anterior and middle cranial fossae. METHODS: First, the authors described the technical nuances of the open-door extended transorbital approach (ODETA). Next, they documented its morphometric advantages over standard SETOA. Finally, they provided a clinical-anatomical application to demonstrate enhanced exposure and better angles of attack to treat lesions occupying the paramedian anterior and middle cranial fossae. Five adult cadaveric specimens (10 sides) initially underwent standard SETOA and then extended open-door SETOA (ODETA to the paramedian anterior and middle fossae). The adjunct of hinge-orbitotomy, through three surgical steps and straddling the frontozygomatic suture, converted conventional SETOA to its extended open-door variant. CT scans were performed before dissection and uploaded to the neuronavigation system for quantitative analysis. The angles of attack on the axial plane that addressed four key landmarks, namely the tip of the anterior clinoid process (ACP), foramen rotundum (FR), foramen ovale (FO), and trigeminal impression (TI), were calculated for both operative techniques and compared. RESULTS: Hinge-orbitotomy of the extended open-door SETOA resulted in several surgical, functional, and esthetic advantages: it provided wider axial angles of attack for each of the target points, with a gain angle of 26.68° ± 1.31° for addressing the ACP (p < 0.001), 29.50° ± 2.46° for addressing the FR (p < 0.001), 19.86° ± 1.98° for addressing the FO (p < 0.001), and 17.44° ± 2.21° for addressing the lateral aspect of the TI (p < 0.001), while hiding the skin scar, avoiding temporalis muscle dissection, preserving flap vascularization, and decreasing the rate of bone infection and degree of orbital content retraction. CONCLUSIONS: The extended open-door technique may be specifically suited for selected patients affected by paramedian anterior and middle fossae lesions, with prevalent anteromedial extension toward the anterior clinoid, the foremost compartment of the cavernous sinus and FR and not completely controlled with the pure endoscopic transorbital approach.

[Microsurgical ventriculostomy of the third ventricle with access through a burrhole in the treatment of midly located deep-seated brain tumors]. / Mikrokhirurgicheskaya ventrikulostomiya III zheludochka s dostupom cherez frezevoe otverstie v lechenii sredinno raspolozhennykh glubinnykh opukholei golovnogo mozga.

BACKGROUND: Currently, endoscopic third ventriculostomy and simultaneous biopsy of deep midline brain tumors are a generally accepted option in neurooncology. Nevertheless, effectiveness of this surgery and diagnostic accuracy of biopsy are not without drawbacks. An alternative to endoscopic surgery may be simultaneous microsurgical third ventriculostomy and biopsy of deep midline tumors. OBJECTIVE: To evaluate effectiveness and safety of burr hole microsurgical third ventriculostomy in the treatment of deep midline brain tumors. MATERIAL AND METHODS: We used transcortical (25 cases) and transcallosal (8 cases) approaches for microsurgical third ventriculostomy. RESULTS: Initially scheduled biopsy was performed in 19 cases, partial resection in 6 cases, subtotal resection in 4 cases and total resection in 4 cases. All patients underwent microsurgical third ventriculostomy. In 12 cases, stenting of stoma was performed in addition to ventriculostomy. Biopsy was informative in all cases. Postoperative follow-up period ranged from 3 to 44 months (mean 29 months). There was no postoperative hydrocephalus and need for shunting procedure. CONCLUSION: Burr hole microsurgery may be an alternative to endoscopic surgery for the treatment of pineal, periaqueductal and third ventricular tumors.

Comparison of the efficacy of neuronavigation-assisted intracerebral hematoma puncture and drainage with neuroendoscopic hematoma removal in treatment of hypertensive cerebral hemorrhage.

OBJECTIVE: To compare neuronavigation-assisted intracerebral hematoma puncture and drainage with neuroendoscopic hematoma removal for treatment of hypertensive cerebral hemorrhage. METHOD: Ninety-one patients with hypertensive cerebral hemorrhage admitted to our neurosurgery department from June 2022 to May 2023 were selected: 47 patients who underwent endoscopic hematoma removal with the aid of neuronavigation in observation Group A and 44 who underwent intracerebral hematoma puncture and drainage in control Group B. The duration of surgery, intraoperative bleeding, hematoma clearance rate, pre- and postoperative GCS score, National Institutes of Health Stroke Scale (NIHSS) score, mRS score and postoperative complications were compared between the two groups. RESULTS: The duration of surgery, intraoperative bleeding and hematoma clearance were significantly lower in Group B than in Group A (p < 0.05). Conversely, no significant differences in the preoperative, 7-day postoperative, 14-day postoperative or 1-month postoperative GCS or NIHSS scores or the posthealing mRS score were observed between Groups A and B. However, the incidence of postoperative complications was significantly greater in Group B than in Group A (p < 0.05), with the most significant difference in incidence of intracranial infection (p < 0.05). CONCLUSION: Both neuronavigation-assisted intracerebral hematoma puncture and drainage and neuroendoscopic hematoma removal are effective at improving the outcome of patients with hypertensive cerebral hemorrhage. The disadvantage of neuronavigation is that the incidence of complications is significantly greater than that of other methods; postoperative care and prevention of complications should be strengthened in clinical practice.

[Preoperative Simulation of Endoscopic Endonasal Approach for Craniopharyngiomas or Tuberculum Sellae Meningiomas].

Preoperative simulation for endoscopic endonasal approach(EEA)using computed tomography and magnetic resonance imaging evaluates tumor extension and the relationship between adjacent structure(the pituitary stalk, major vessels, and cranial nerves); therefore, preoperative planning of nasal procedure, skull base bony removal, and cranial base reconstruction are possible. Additionally, three-dimensional(3D)fusion image aids surgeons to visualize intraoperative 3D findings. These preoperative simulations are critical to avoid complications and predict pitfalls perioperatively. However, tumor consistency or adhesion with adjacent structure cannot be predicted but is judged perioperatively, which affects the extent of tumor resection. This manuscript describes important points of preoperative simulation for EEA, especially the transplanum-transtuberculum approach for craniopharyngiomas or tuberculum sellae meningiomas, showing some examples in patients.

Customized ventral bony and dural opening in the transplanum/transtuberculum and transclival variants of extended endoscopic endonasal approach to suprasellar craniopharyngiomas: an approach-based stepwise cadaveric dissection and clinical applicability.

BACKGROUND: Optimal initial exposure through an extended endoscopic endonasal approach (EEA) for suprasellar craniopharyngiomas ensures safe and unrestricted surgical access while avoiding overexposure, which may prolong the procedure and increase neurovascular adverse events. METHOD: Here, the authors outline the surgical nuances of a customized bony and dural opening through the transplanum/transtuberculum and transclival variants of the extended EEA to suprasellar craniopharyngiomas based on the tumor-pituitary stalk relationship. A stepwise cadaveric dissection and intraoperative photographs relevant to the approaches are also provided. CONCLUSION: Safe maximal resection of suprasellar craniopharyngiomas through extended EEAs can be feasibly and safely achieved by implementing of tailored ventral exposure.

Stereotactic anatomy of the third ventricle.

PURPOSE: Endoscopic third ventriculostomy (ETV) is a surgical procedure that can lead to complications and requires detailed preoperative planning. This study aimed to provide a more accurate understanding of the anatomy of the third ventricle and the location of important structures to improve the safety and success of ETV. METHODS: We measured the stereotactic coordinates of six points of interest relative to a predefined stereotactic reference point in 23 cadaver brain hemi-sections, 200 normal brain magnetic resonance imaging (MRI) scans, and 24 hydrocephalic brain MRI scans. The measurements were statistically analyzed, and comparisons were made. RESULTS: We found some statistically significant differences between genders in MRIs from healthy subjects. We also found statistically significant differences between MRIs from healthy subjects and both cadaver brains and MRIs with hydrocephalus, though their magnitude is very small and not clinically relevant. Some stereotactic points were more posteriorly and inferiorly located in cadaver brains, particularly the infundibular recess and the basilar artery. It was found that all stereotactic points studied were more posteriorly located in brains with hydrocephalus. CONCLUSION: The study describes periventricular structures in cadaver brains and MRI scans from healthy and hydrocephalic subjects, which can guide neurosurgeons in planning surgical approaches to the third ventricle. Overall, the study contributes to understanding ETV and provides insights for improving its safety and efficacy. The findings also support that practicing on cadaveric brains can still provide valuable information and is valid for study and training of neurosurgeons unfamiliar with the ETV technique.

Rarely Used Endoscopic Transnasal Transdiaphragmatic Technique in Patients with Suprasellar Extension: A Tertiary Center's Experience with Eleven Patient Cases.

OBJECTIVE: As surgical techniques become less invasive, the use of endoscopy in brain surgery supports this trend. Numerous endoscopic surgical approaches have been defined, especially for skull base diseases. The current study summarizes our experience of using the rarely reported endoscopic transnasal transdiaphragmatic approach through the existing hole in the diaphragma sella to access lesions extending into the suprasellar region. METHODS: Our surgical team performed 4876 endoscopic endonasal surgeries between August 1997 and December 2022 at the Department of Neurosurgery, Pituitary Research Center, Faculty of Medicine, Kocaeli University. The study retrospectively analyzed data from 11 patients who had undergone endoscopic transnasal transdiaphragmatic surgery since January 2020. Preoperative and postoperative magnetic resonance imaging, pituitary function examination, and clinical observation were carried out. RESULTS: The mean age of the patients was 31.1 ± 10.7 years and the female/male ratio was 6:5. Pathologic subtypes observed included breast cancer metastasis (n = 1), adrenocorticotropic hormone-secreting adenoma (n = 4), growth hormone-secreting adenoma (n = 3), craniopharyngioma (n = 2), and Rathke cleft cyst (n = 1). The mean postoperative hospital stay was 4.7 ± 1.1 days and none of the patients showed cerebrospinal fluid leakage during this period. CONCLUSIONS: The endoscopic transnasal transdiaphragmatic approach may be considered an alternative to the conventional extended endoscopic transnasal approach in patients with lesions extending into the suprasellar region. The main strength of this method is that it facilitates suprasellar region access through a small dural incision and bone defect in the base of the skull. As a result, it also reduces the risk of postoperative cerebrospinal fluid leakage and associated complications.

How I do it: endoscopic evacuation of intraventricular lesions using a flexible endoscope in combination with an angiographic catheter.

BACKGROUND: In intraventricular surgery using a flexible endoscope, the lesion is usually aspirated via the working channel. However, the surgical view during aspiration is extremely poor because the objective lens is located adjacent to the working channel. METHOD: To address this issue, we developed a novel surgical procedure using an angiographic catheter. In this procedure, the catheter is inserted into the working channel, and the lesion is aspirated through the catheter. Besides, continuous intraventricular irrigation is performed via the gap between the catheter and the working channel. CONCLUSION: This procedure maintains a clear view during surgery and reduces complications.

Septostomy and Monroplasty in Isolated Lateral Ventricle After Removal of a Third Ventricle Colloid Cyst: 2-Dimensional Operative Video.

Isolated unilateral hydrocephalus (IUH) is a condition caused by unilateral obstruction of the foramen of Monro.1 Etiopathogenic causes include tumors, congenital lesions, infective ventriculitis, intraventricular haemorrhage, and iatrogenic causes such as the presence of contralateral shunts.2,3 Neuroendoscopic management is considered the "gold-standard" treatment in IUH.4 Even if endoscopic septostomy and foraminoplasty in IUH are well-known procedures,5,6 IUH after an interhemispheric transcallosal transchoroidal approach for removal of a III ventricle colloid cyst is a complication barely described in literature. Video 1 describes this rare complication and the neuroendoscopic treatment adopted, including the operative room setup, patient's positioning, instrumentation needed, and a series of intraoperative tips for the performance of septostomy and Monroplasty via a single, precoronal burr hole. The scalp entry point and endoscope trajectory, homolateral to the dilated ventricle, were planned on the neuronavigation system. The avascular septal zone away from the septal veins and body of the fornix was reached, and the ostomy was performed. At the end of the procedure, Monroplasty was performed, too. The procedure was effective in solving the hydrocephalus and patient's clinical picture. No surgical complications occurred. Imaging demonstrated an evident and progressive reduction of enlarged lateral ventricle. In authors' opinion, the single burr-hole approach, ipsilateral to the enlarged ventricle, provides an optimal identification the intraventricular anatomy and allows Monroplasty to be performed, if deemed feasible during surgery. The patient consented to the procedure. The participants and any identifiable individuals consented to publication of their images.

Endoscopic third ventriculostomy (ETV) or ventriculoperitoneal shunt (VPS) for paediatric hydrocephalus due to primary aqueductal stenosis.

PURPOSE: The purpose of this study was to compare outcomes of endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt (VPS) in children with symptomatic triventricular hydrocephalus due to primary aqueductal stenosis. METHOD: This is a retrospective analytical study. Patients who underwent either ETV or VPS as the first procedure for hydrocephalus due to primary aqueductal stenosis were included in the study. RESULT: A total of 89 children were included in the study for analysis. The mean age was 8.4 years. Forty-four (49.4%) had their first surgery as ETV and 45 (50.6%) had their first surgery as VPS. Overall, 34 (38.2%) patients required a second surgery (either ETV or VPS) for persistent or recurrent hydrocephalus. The mean follow-up duration was 832.9 days. The overall complication rate was 13.5%. The mean timing of the second surgery after index surgery was 601.35 days. Factors associated with a second surgery were the presence of complications, high protein in cerebrospinal fluid, the relative change of frontal-occipital horn ratio (FOHR) and Evans' index. The survival of the first surgery was superior in ETV (751.55 days) compared to VPS (454.49 days), p = 0.013. The relative change of fronto-occipital horn index ratio (FOIR) was high in the VPS (mean 7.28%) group compared to the ETV (mean 4.40%), p = 0.001 group. CONCLUSION: Overall procedural survival was better after ETV than VPS for hydrocephalus due to aqueductal stenosis. VPS causes more reduction in linear indices of ventricles as compared to ETV, however, is not associated with the success or complication of the procedure.

Treatment of Pineal Region Lesions in Children.

BACKGROUND: Pineal region lesions are more common in children than adults; however, therapeutic strategies for pineal region lesions in children are controversial. METHODS: A retrospective study involving 54 pediatric with pineal region lesions was conducted. The therapeutic strategies for lesions and hydrocephalus were classified and analyzed. RESULTS: Radiotherapy of pineal region lesions was shown to result in better postoperative recovery and fewer complications in the short-term compared with lesion resection. Total resection was related to smaller lesion size, endoscopic procedures, and a better prognosis. Cerebrospinal fluid (CSF) diversion before the resection reduced hydrocephalus recurrences, whereas further lesion resection had a negative short-term influence on CSF diversion. Among the 4 therapeutic strategies to manage hydrocephalus, a third ventriculostomy (ETV) was reasonable and further resection did not have a negative impact on the ETV. The relief of hydrocephalus was also related to better postoperative recovery, a higher total resection rate, fewer complications, and a better prognosis. Logistical regression analysis indicated that lesion size and intracranial complications were predictors of outcome. CONCLUSIONS: For lesion treatment, total resection and radiotherapy are essential components in children. Total resection and CSF diversion before resection were beneficial, whereas further lesion resection had a negative impact on CSF diversion. For hydrocephalus treatment, ETV was shown to be the best therapeutic strategy for management of pediatric hydrocephalus. Total resection and better preoperative health status were associated with greater hydrocephalus relief. For the overall prognosis, a lack of hydrocephalus relief was associated with poor outcomes. Lesion size and intracranial complications may be the best predictors of outcome.

Minimally invasive endoscopic evacuation with the novel, portable Axonpen neuroendoscopic system for spontaneous intracerebral hemorrhage.

Minimally invasive surgeries have shown potential to improve mortality and clinical outcomes of spontaneous intracerebral hemorrhage (ICH). The present study assessed the first-in-human outcomes of a novel, portable neuroendoscopic system for ICH evacuation at our single center. This neuroendoscopic system integrates real-time visualization into a handpiece which has controllable suction, irrigation, and coagulation to allow a neurosurgeon to conduct minimally invasive ICH evacuation independently with bimanual dexterity. Pre- and postoperative data of ten patients who had spontaneous basal ganglia hemorrhage (mean: 46.5 ± 12.2 mL) and underwent evacuation with the specified neuroendoscopic system were collected prospectively. The mean time to receive surgery was 12.1 ± 7.6 h. Mean operative time was 3.4 ± 0.9 h. The mean hematoma volume decreased to 6.0 ± 3.9 mL at postoperative 6 h, resulting in a mean volume reduction of 86.0 ± 11.2% (P = 0.005). The median length of intensive care unit stay was 3 days (IQR, 3-4 days). At discharge, the median Glasgow Coma Scale (GCS) score significantly improved to 11.5 (IQR, 11-15; P = 0.016), and the median modified Rankin Scale (mRS) score was 4 (IQR, 4-5). Six patients (60%) showed a favorable mRS score of ≤ 3 on their last return visit. Neither death nor rebleeding occurred during the follow-up periods. Integrated design of the innovative device is valuable to optimize minimally invasive endoscopic ICH evacuation procedure. Further studies are needed to clarify long-term benefits from such type of the innovative device to early intervention of ICH.

Factors associated with in-hospital mortality in HIV-infected children treated for tuberculous meningitis hydrocephalus.

PURPOSE: The study aimed to investigate factors associated with in-hospital mortality in children diagnosed with tuberculous meningitis (TBM) hydrocephalus and HIV co-infection undergoing cerebrospinal fluid diversion procedures and their complications. METHODS: Data were collected retrospectively and prospectively between 2007 and 2022. Data collected included demographics, clinical characteristics, antiretroviral therapy (ART) status, biochemistry results, CD4 count, radiology findings, CSF diversion procedures (and complications), length of hospital stay (LOHS), and in-hospital mortality. RESULTS: Thirty-one children were included, with a mean age of 6.7 ± 5.3 years and 67.7% males. Median admission Glasgow Coma Scale (GCS) was 11 (IQR 9-15). Hypertonia (64.5%) and seizures (51.6%) were frequently observed clinical characteristics. Sixty-one percent of children were on ART. Cerebral infarcts and extra-meningeal TB were diagnosed in 64.5% and 19.3% of cases, respectively. The median CD4 count was 151 (IQR 70-732) cells/µL. Surgical procedures included ventriculoperitoneal shunt (VPS) in 26 cases and endoscopic third ventriculostomy (ETV) in five children. VPS complication rate was 27%. No complications were reported for ETV. Median LOHS was 7 days (IQR 4-21). Eleven children (35.5%) died during admission. Factors associated with mortality included GCS (p = 0.032), infarcts (p = 0.004), extra-meningeal TB (p = 0.003), VPS infection (p = 0.018), low CD4 count (p = 0.009), and hyponatremia (p = 0.002). No statistically significant factors were associated with VPS complications. CONCLUSION: TBM hydrocephalus in HIV-infected children carries a high mortality. Clinicians in high-prevalence settings should have a high suspicion index and institute early treatment.

The biportal transorbital approach: quantitative comparison of the anterior subfrontal craniotomy, bilateral transorbital endoscopic, and microscopic approaches.

OBJECTIVE: The aim of this study was to assess the surgical use and applicability of a biportal bitransorbital approach. Single-portal transorbital and combined transorbital transnasal approaches have been used in clinical practice, but no study has assessed the surgical use and applicability of a biportal bitransorbital approach. METHODS: Ten cadaver specimens underwent midline anterior subfrontal (ASub), bilateral transorbital microsurgery (bTMS), and bilateral transorbital neuroendoscopic surgery (bTONES) approaches. Morphometric analyses included the length of the bilateral cranial nerves I and II, the optic tract, and A1; the area of exposure of the anterior cranial fossa floor; craniocaudal and mediolateral angles of attack (AOAs); and volume of surgical freedom (VSF; maximal available working volume for a specific surgical corridor and surgical target structure normalized to a height of 10 mm) of the bilateral paraclinoid internal carotid arteries (ICAs), bilateral terminal ICAs, and anterior communicating artery (ACoA). Analyses were conducted to determine whether the biportal approach was associated with greater instrument freedom. RESULTS: The bTMS and bTONES approaches provided limited access to the bilateral A1 segments and the ACoA, which were inaccessible in 30% (bTMS) and 60% (bTONES) of exposures. The average total frontal lobe area of exposure (AOE) was 1648.4 mm2 (range 1516.6-1958.8 mm2) for ASub, 1658.9 mm2 (1274.6-1988.2 mm2) for bTMS, and 1914.9 mm2 (1834.2-2014.2 mm2) for bTONES exposures, with no statistically significant superiority between any of the 3 approaches (p = 0.28). The bTMS and bTONES approaches were significantly associated with decreases of 8.7 mm3 normalized volume (p = 0.005) and 14.3 mm3 normalized volume (p < 0.001) for VSF of the right paraclinoid ICA compared with the ASub approach. No statistically significant difference in surgical freedom was noted between all 3 approaches when targeting the bilateral terminal ICA. The bTONES approach was significantly associated with a decrease of 105% in the (log) VSF of the ACoA compared with the ASub (p = 0.009). CONCLUSIONS: Although the biportal approach is intended to improve maneuverability within these minimally invasive approaches, these results illustrate the pertinent issue of surgical corridor crowding and the importance of surgical trajectory planning. A biportal transorbital approach provides improved visualization but does not improve surgical freedom. Furthermore, although it affords impressive anterior cranial fossa AOE, it is unsuitable for addressing midline lesions because the preserved orbital rim restricts lateral movement. Further comparative studies will elucidate whether a combined transorbital transnasal route is preferable to minimize skull base destruction and maximize instrument access.

Endoscopic transaqueductal stent placement for tumor-related aqueductal compression in pediatric patients: surgical consideration, technique, and results.

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.