OBJECTIVE: Intraventricular hemorrhage (IVH) of prematurity occurs in 20-38% of infants born < 28 weeks gestational age and 15% of infants born in 28-32 weeks gestational age. Treatment has evolved from conservative management and CSF diversion of temporizing and shunting procedures to include strategies aimed at primarily clearing intraventricular blood products. Neuroendoscopic lavage (NEL) aims to decrease the intraventricular blood burden under the same anesthetic as temporizing CSF diversion measures in cases of hydrocephalus from IVH of prematurity. Given the variety of neuroendoscopes, we sought to review the literature and practical considerations to help guide neuroendoscope selection when planning NEL.
METHODS: We conducted a systematic review of the literature on neuroendoscopic lavage in IVH of prematurity to examine data on the choice of neuroendoscope and outcomes regarding shunt rate. We then collected manufacturer data on neuroendoscopic devices, including inflow and outflow mechanisms, working channel specifications, and tools compatible with the working channel. We paired this information with the advantages and disadvantages reported in the literature and observations from the experiences of pediatric neurosurgeons from several institutions to provide a pragmatic evaluation of international clinical experience with each neuroendoscope in NEL.
RESULTS: Eight studies were identified; four neuroendoscopes have been used for NEL as reported in the literature. These include the Karl Storz Flexible Neuroendoscope, LOTTA® system, GAAB system, and Aesculap MINOP® system. The LOTTA® and MINOP® systems were similar in setup and instrument options. Positive neuroendoscope features for NEL include increased degrees of visualization, better visualization with the evolution of light and camera sources, the ability to sterilize with autoclave processes, balanced inflow and outflow mechanisms via separate channels, and a working channel. Neuroendoscope disadvantages for NEL may include special sterilization requirements, large outer diameter, and limitations in working channels.
CONCLUSIONS: A neuroendoscope integrating continuous irrigation, characterized by measured inflow and outflow via separate channels and multiple associated instruments, appears to be the most commonly used technology in the literature. As neuroendoscopes evolve, maximizing clear visualization, adequate inflow, measured outflow, and large enough working channels for paired instrumentation while minimizing the footprint of the outer diameter will be most advantageous when applied for NEL in premature infants.

UNASSIGNED: Transsphenoidal surgery, including endoscopic and microscopic resection, is the first choice of treatment for pituitary tumors. With the widespread application of neuroendoscopy in recent decades, there has been a trend to replace microscopes. In clinical practice, we have found that in transsphenoidal surgery for non-invasive microadenomas and macroadenomas, microscopy can achieve a higher total resection rate, shorter operation time, lower incidence of postoperative complications, and faster recovery of olfaction. This study aimed to explore the selection of endoscopes and microscopes for non-aggressive transsphenoidal surgery for pituitary adenomas and the factors affecting olfactory recovery.
UNASSIGNED: From August 2019 to October 2022, 93 patients with non-aggressive microadenomas and macroadenomas via the transsphenoidal approach were selected from the First Affiliated Hospital of Harbin Medical University and treated with rich experience in pituitary tumor subspecialty microscopy and endoscopic surgery. Different surgical methods were used to divide the patients into microscopic (n = 35) and endoscopic (n = 58) groups. The total tumor removal rate, intraoperative blood loss, operation time and cost, postoperative hospital stay, recovery of visual function, postoperative changes in hormone levels, complication rate, and recovery from complications 3 months after the operation were compared between the two groups.
UNASSIGNED: There were no significant differences in the tumor removal rate, postoperative visual acuity, and visual field recovery between the two groups (p > 0.05). There was a significant difference in the recovery rate of olfactory function between the two groups 3 months after the operation (p < 0.05), and there was no significant difference in the incidence of other complications (p > 0.05); Compared with the two groups, the microscope group had shorter operation time, longer postoperative hospital stay, less average operation cost and less blood loss, and the difference was statistically significant (p < 0.05). The position of the nasal septum mucosal flap incision was a risk factor for hyposmia 3 months after the operation.
UNASSIGNED: Microsurgery and endoscopic surgery are suitable surgical treatments for nonaggressive microadenomas and macroadenomas. The total tumor removal and postoperative hormone remission rates of the two surgical methods were approximately the same. However, the microsurgery group had a shorter operation time, less intraoperative blood loss, faster olfactory function recovery, and a lower average operation cost. The position of the nasal septal mucosal flap incision was a risk factor for hyposmia at 3 months postoperatively. Hyposmia is less likely to occur when the superior edge of the nasal septal mucosal flap incision is not higher than the lower edge of the ipsilateral superior turbinate.

Pure endoscopic technique in resection of intraventricular tumors is an emerging technology. This case demonstrates resection of a multicentric choroid plexus papilloma in a 2-month-old child. This child had two district tumors: one located in the left atrium and another in the third ventricle. Initial microsurgery was performed to resect the left atrial tumor. With the tumor noted to be not very vascular at initial surgery, the third ventricle tumor was resected with a GAAB neuroendoscope and NICO Myriad. A gross-total resection was achieved. At 3 years\' follow-up, the child remains tumor free and developing without any functional deficits. The video can be found here: https://stream.cadmore.media/r10.3171/2023.1.FOCVID22145.

Post-hemorrhagic hydrocephalus (PHH) in preterm infant is common, life-threatening and the main cause of bad developmental outcomes. Ventriculoperitoneal (VP) shunt is used as the ultimate treatment for PHH. Low birth weight and low gestational age are the combination of worse prognostic factors while the single most important prognostic factor of VP shunting is age. Aggressive and early intervention have better effect in intraventricular hemorrhage and intracranial pressures control. It reduces infection rate and brain damage resulted in delayed shunt insertion. It is extremely important to let PHH infants get older and gain weight to have internal organs to be matured before undergoing VP shunt. As premature infants undergo shunt after further growth, shunt-related complications would be reduced. So temporary surgical intervention is critical for PHH infants to have them enough time until permanently shunted.

UNASSIGNED: Embolization of the middle meningeal artery (MMA) has been established for chronic subdural hematoma (CSDH). Neuroendoscopic observation of the outer membrane of the hematoma was carried out after embolization. The treatment mechanism of embolization is discussed, focusing on the vasculature and inflammation of the membrane.
UNASSIGNED: Four patients with recurrent CSDH were included in this study. The MMA was embolized using Embosphere® particles in three patients. The outer membrane was observed with normal and narrow band images (NBIs).
UNASSIGNED: The net-like vessels were not obstructed in the whole area of the outer membrane, but in a patchy fashion of embolized areas surrounded by nonembolized areas. In two patients, the nonembolized areas showed a hemorrhagic inflammatory red color. Histopathological examination confirmed hypertrophic dura with leukocyte infiltration. Dilated dural arteries and proliferated sinusoid arteries were located in the deep and superficial border cell layers. These arteries were visualized as green and brown on NBI, respectively. In the embolized area, the red membrane turned pink, indicating ischemia and subsiding inflammatory hyperemia. In the third patient, the outer membrane was white in both the nonembolized and embolized areas in endoscopic view, and the net-like vessels were sparse in both endoscopy and histology, indicating a scar inflammatory phase. The membrane transition was not observed in the patient that did not undergo embolization.
UNASSIGNED: Endoscopic observation revealed that embolization of the MMA blocked both the dural and sinusoidal arteries. Ischemic transformation causing the suppression of inflammation of the outer membrane is a suggested mechanism of MMA embolization.

Acute subdural hematoma (ASDH), which causes midline shift of the brain, rarely arises from a dural arteriovenous fistula (DAVF). Herein, we report the first case of a DAVF manifesting ASDH, which was treated less invasively with endovascular embolization of a drainer of the DAVF and hematoma removal under neuroendoscopy. A 59-year-old man with a sudden onset of headache was transported to our hospital. Left ASDH and intracerebral hematoma in the left occipital lobe were detected. A cerebral angiogram revealed a DAVF fed by the petrosquamous branch of the left middle meningeal artery and jugular branch of the right ascending pharyngeal artery. The shunting point in the lateral tentorial DAVF drains through the internal occipital vein to the superior sagittal sinus. A varix was recognized in the draining vein (Borden type 3, Cognard type 4). The DAVF was embolized with Onyx (Medtronic, Minnesota, USA), and the left ASDH was removed with a small craniotomy under neuroendoscopy. No origin of the left ASDH was apparent in the surgical field. The patient was discharged from the hospital on postoperative day 18. The patient\'s status was modified Rankin scale 1 on discharge. Our management of combined endovascular treatment and neuroendoscopic hematoma removal may be useful and less invasive for hemorrhagic DAVF.

Subependymoma (SE) is a rare, usually asymptomatic, brain tumor predominantly affecting older adults and occurring in the fourth and lateral ventricles. We report a rare case of SE with intratumoral hemorrhage that could be removed by neuroendoscopy. The 81-year-old patient had been followed as an outpatient for 10 years due to an intraventricular tumor. It did not grow over the patient\'s lengthy follow-up. The patient was transferred to our hospital after he fainted near his home; at the time of admission, he had mild consciousness disturbance, and his Glasgow Coma Scale score was 10 points (E3V3M4). Computed tomography showed intratumoral hemorrhage and slight ventricular enlargement. Magnetic resonance (MR) imaging showed a 4 cm-sized tumor in the anterior horn of the right lateral ventricle. The lesion appeared as a mixed-intensity solid tumor and showed irregular enhancement with gadolinium. The patient underwent neuroendoscopic tumor resection on the 30th day of the patient\'s hospital stay. A histopathological examination revealed small tumor cells with round nuclei scattered in the glial fibrillary background. Immunostaining was positive for glial fibrillary acidic protein; these findings are consistent with an SE diagnosis. The patient in this study had hypertension and used anticoagulants, risk factors for intratumoral hemorrhage. For intraventricular tumors with bleeding-particularly in older or more physically frail patients-minimally invasive neuroendoscopic surgery should be considered an option for tumor resection.

UNASSIGNED: In recent years, the efficacy of 5-aminolevulinic acid photodynamic diagnosis (5-ALA PDD) has been reported for various types of brain tumors, including malignant glioma. In addition, many reports have been published on the usefulness of neuroendoscopic surgery for intraventricular lesions. However, no systematic report is available on the combined use of 5-ALA PDD and neuroendoscopy for various intraventricular tumors.
UNASSIGNED: We report 17 consecutive patients with intraventricular tumors. All patients received oral 5-ALA preoperatively and underwent endoscopic surgical treatment (resection or biopsy). We use a rigid endoscope with a built-in PDD system for intraoperative observation.
UNASSIGNED: Seven resections and 10 biopsies were performed. Histopathological diagnosis was confirmed in all 17 cases. Gross total resection was achieved in six of seven cases. The fluorescence positivity rates for each tumor were glioblastoma 100% (2/2), low-grade glioma 67% (2/3), subependymoma 0% (0/1), medulloblastoma 100% (1/1), pineoblastoma 0% (0/1), germ cell tumor 75% (3/4), diffuse large B-cell lymphoma 33% (1/3), and metastatic tumor 100% (2/2).
UNASSIGNED: Our method has the potential to improve detection of residual tumors in blind spots and deep areas, as well as the accuracy and safety of biopsy procedures for intraventricular lesions that are difficult to view and treat under a microscope.

[This corrects the article DOI: 10.3389/fonc.2021.774462.].

OBJECTIVE: To explore the role of neuroendoscope assistance during surgical resection of the intracanalicular portion of vestibular schwannomas via the retrosigmoid approach and the subsequent early facial nerve outcomes.
METHODS: Patients of vestibular schwannoma with intracanalicular extensions undergoing retrosigmoid dissection at a single institution were retrospectively analyzed in this study. Several surgical techniques were applied to ensure maximal and safe removal of tumors. Tumors extending less than 10 mm into the internal acoustic canal (IAC) were classified as Grade A, while those extending over 10 mm into IAC were taken as Grade B. Neuroendoscope was applied at the end of microscopic phase to search for potential remnants for Grade B tumors. Absolute tumor extension was defined and measured. House and Brackmann (HB) scale was used to evaluate immediate CN VII outcomes.
RESULTS: Of the 61 patients, there were 38 females and 23 males. A total of 18 (29.51%) cases were Koos Grade II, 12 (19.67%) cases Koos Grade III, and 31 (50.82%) cases Koos Grade IV. There were 38 cases (62.30%) of Grade A and 23 cases (37.70%) of Grade B. Gross total resection was achieved in 60 cases (98.36%). Four cases of intracanalicular remnants were detected and completely removed under endoscopic visualizations. There was a significantly higher proportion (17%, p = 0.02) of intracanalicular remnants in Grade B than Grade A. CN VII and VIII were anatomically preserved in all cases. A total of 55 cases (90.16%) retained good (HB Grades 1 and 2) facial nerve outcomes.
CONCLUSIONS: In Grade B vestibular schwannomas, after maximal microsurgical removal, endoscopic evaluation of the intracanalicular portion revealed residual tumors in 17% of the patients. Hence endoscopic evaluation of the potential intracanalicular remnants for tumor extending over 10 mm within IAC (Grade B) is recommended.