Endoneurosurgical Resection of Parenchymal and Intraventricular Lesions Using Tubular Retraction System.

OBJECTIVE: Endoscopic surgery has emerged in the recent years as an alternative to the conventional microsurgical approaches for removal of the deep-seated brain and intraventricular tumors. Endoport has enhanced the tumor access and visualization without any significant brain retraction. In this chapter, we describe the surgical technique of the endoscopic excision of the deep-seated intra-axial brain tumors using tubular retraction system with review of the literature. METHODS: The endoscopic endoport technique that we use at our institution for the surgical management of intraventricular and intraparenchymal brain tumors has been described in details with illustrations. RESULTS: Results from the literature review of brain parenchymal and intraventricular port surgery were analyzed, and the feasibility and safety of this technique were discussed. Surgical complication avoidance and management were highlighted. The port technique offers numerous potential advantages, including: (1) reducing focal brain injury by distributing retraction forces homogenously; (2) minimizing white matter disruption and the risk of fascicles injury during cannulation; (3) ensuring stability of the surgical corridor during the procedure; (4) preventing inadvertent expansion of the corticectomy and white fiber tract dissection throughout surgery; (5) protecting the surrounding tissues against iatrogenic injuries caused by instrument entry and reentry. CONCLUSION: The endoport-assisted endoscopic technique is a safe and minimally invasive method that offers an effective alternative option for resection of intraventricular and parenchymal brain lesions. Excellent outcome comparable to other surgical approaches can be achieved with acceptable complications.

Fully Endoscopic Nontubular Retractor Approach for Intraaxial Tumors.

BACKGROUND: Fully endoscopic or endoscope-controlled approaches are essentially keyhole approaches in which rigid endoscopes are the sole visualization tools used during the whole procedure. At the early attempts of endoscope-assisted cranial surgery, it was noted that rigid endoscopes enabled overcoming the problem of suboptimal visualization when small exposures are used. The technical specifications and design of the currently available rigid endoscopes are associated with a group of unique features that define the endoscopic view and lay the basis for its superiority over the microscopic view during brain surgery. Fully endoscopic resection of intraparenchymal brain tumors is a minimally invasive approach that is not routinely practiced by neurosurgeons, with a few major series published so far. Unfamiliarity with the technique, steep learning curve, and concerns about inadequate exposure and decreased visibility may explain this fact. The majority of the purely endoscopic resections for intraparenchymal brain lesions are performed nowadays through tubular retractor systems. In very limited instances, however, the fully endoscopic technique is performed without tubular retractors. In this chapter, we elaborate on the surgical technique and nuances of the fully endoscopic nontubular retractor approach for intraaxial tumors. METHODS: From a prospective database of endoscopic procedures maintained by the senior author, clinical data, imaging studies, and operative charts and videos of cases undergoing fully endoscopic excision for intraaxial brain tumors were retrieved and analyzed. The pertinent literature was also reviewed. RESULTS: The surgical technique of the fully endoscopic nontubular retractor approach for intraaxial tumors was formulated. CONCLUSION: The endoscopic technique has many advantages over the conventional procedures. In our hands, the technique has proven to be feasible, efficient, and minimally invasive with excellent results.

Endoport-Guided Endoscopic Excision of Intraaxial Brain Tumors.

OBJECTIVE: Transcortical approaches using a spatula-based retraction system have traditionally been used for the microsurgical resection of deep-seated intraventricular and parenchymal brain tumors. Recently, transparent cylindrical or tubular retractors have been developed to provide a stable corridor to access deeper brain lesions and perform bimanual microsurgical resection. The flexible endoports minimize brain retraction injury during surgery and, along with the superior vision of endoscopes, offer several advantages over standard microsurgery. In this chapter, we describe the surgical technique of the endoport-guided endoscopic excision of deep-seated intraaxial brain tumors. METHODS: The endoscopic endoport technique that we use at our institution for the surgical management of intraventricular and intraparenchymal brain tumors has been described in detail with illustrative cases. RESULTS: Results from the literature review of intraventricular and intraparenchymal port surgery were analyzed, and the feasibility and safety of this technique were discussed. Surgical complication avoidance and management were highlighted. The port technique offers numerous potential advantages, including (1) reducing focal brain injury by distributing retraction forces homogenously, (2) minimizing white matter disruption and the risk of fascicle injury during cannulation, (3) ensuring the stability of the surgical corridor during the procedure, (4) preventing inadvertent expansion of the corticectomy and white fiber tract dissection throughout surgery, and (5) protecting the surrounding tissues against iatrogenic injuries caused by instrument entry and reentry. CONCLUSION: The endoport-assisted endoscopic technique is safe and offers an effective alternative option for the resection of intraventricular and intraparenchymal lesions.

Optimizing outcomes in multicompartmental brain tumor surgery: A comparative study of integrated endoscopic and microsurgical techniques versus endoscope-assisted microsurgery.

BACKGROUND: Multicompartmental lesions within the central nervous system are challenging due to their complex anatomy. This study evaluates the efficacy, safety, and utility of hybrid endoscopic and microsurgery versus endoscope-assisted microsurgery(EAM) for excising these lesions. METHODS: A retrospective comparative analysis was conducted on patients who underwent multicompartmental brain tumor surgery, utilizing either hybrid endoscopic and microsurgical techniques with the Endocameleon Hopkins telescope featuring a rotating lens system and knob (Karl Storz GmbH & Co., Tuttlingen, Germany), alternately used with a microscope (ZEISS PENTERO 800 S) (Group 1, n = 69), or endoscope-assisted microsurgery employing a fully high-definition, 45° angled endoscopic tool, QEVO®, integrated into the digital surgical microscope KINEVO 900 (Carl Zeiss Meditec, Oberkochen, Germany) as a plug-in feature (Group 2, n = 63), from July 2018 to March 2024. Data on demographics, clinical presentation, lesion characteristics, surgical details, and outcomes were meticulously collected and analyzed using rigorous statistical methods, including t-tests and chi-square tests. RESULTS: Compared to Group 2, Group 1 had better ease of dissection and visualization of bleeders (p = 0.01) and fewer postoperative hematomas (p = 0.04). Surgical times were similar (p = 0.134). Postoperative follow-up revealed fewer recurrences in Group 1, though not statistically significant (p = 0.33). Group 1 patients reported higher cosmetic satisfaction and shorter hospital stays (p = 0.002). Logistic regression identified tumor vascularity(p = 0.001) and ease of dissection(p = 0.008) as significant factors for recurrence. CONCLUSIONS: Hybrid endoscopic and microsurgery demonstrated superior intraoperative visualization, ease of dissection, and postoperative outcomes compared to endoscope-assisted microsurgery with the Quevo device. These findings suggest that the integrated approach may offer better outcomes for multicompartmental lesion excision regarding safety, efficacy, and patient satisfaction.

Piezosurgery in endoscopic-assisted trigonocephaly correction: a technical note.

PURPOSE: This study aims to evaluate the effectiveness of the Piezosurgery® device in endoscopic-assisted correction of trigonocephaly. Trigonocephaly is a type of craniosynostosis characterized by a triangular-shaped forehead due to the premature fusion of the metopic suture. Traditional open cranial vault reconstruction, although common, is invasive and poses risks. The study explores a less invasive alternative using ultrasonic microvibrations for bone cutting, potentially reducing soft tissue damage and improving surgical outcomes. METHODS: The Piezosurgery® device was employed in endoscopic trigonocephaly correction surgeries performed on patients under 4 months old at the French Referral Center for Craniosynostosis in Lyon. The technique involves making a small skin incision and performing osteotomies from the anterior fontanel to the glabella. A rigid 0° endoscope provides visibility, and the Piezosurgery® device enables precise bone cutting while preserving the dura mater. Post-surgery, patients were discharged within 3 days and required to wear a remodeling helmet for 6-8 months. RESULTS: The use of Piezosurgery® device allowed precise osteotomies with minimal soft tissue damage. No dura mater injuries occurred in the patient series. The procedure was efficient, with an average duration of 80 min, and blood loss was minimal, reducing the need for blood transfusions. The endoscopic approach facilitated shorter surgical times and reduced postoperative infection risks. Enhanced visibility during surgery, due to cavitation effects, improved the accuracy of bone cuts. The technique demonstrated promising safety and esthetic outcomes, although it incurred higher costs compared to traditional methods. CONCLUSION: Piezosurgery® device provides a safe and effective method for minimally invasive endoscopic correction of trigonocephaly. The device's ability to selectively cut bone while preserving soft tissues offers significant advantages, despite longer surgical times and higher costs. This technique represents a viable alternative to traditional open surgery, promoting better clinical outcomes and reduced recovery times.

A novel endoscope-port unit for lumbar microendoscopic surgery: a single-center case series review.

Minimally invasive spinal surgery has shown benefits not only from a clinical standpoint but also in some cost-effectiveness metrics. Microendoscopic procedures combine optical advantages of endoscopy with the preservation of bimanual surgical maneuvers that are not feasible with full percutaneous endoscopic procedures. TELIGEN is a new endoscopic platform designed to optimize these operations. Our aim was to present a retrospective review of surgical data from the first consecutive cases applying this device in our institution and describe some of its technical details. 25 patients have underwent procedures using this device at our institution to the date, with a mean follow-up of 341.7 ± 45.1 days. 17 decompression-only procedures, including microendoscopic discectomies (MED) and decompression of stenosis (MEDS), with or without foraminotomies (± MEF) and 8 microendoscopic transforaminal lumbar interbody fusions (ME-TLIF) were performed. Mean age and body mass index (BMI) were respectively 58.8 ± 17.4 years and 27.6 ± 5.3 kg/m2. Estimated blood loss (13 ± 4.8, 12.8 ± 6.98 and 76.3 ± 35.02 mL), postoperative length of hospital stay (11.2 ± 21.74, 22.1 ± 26.85 and 80.7 ± 44.60 h), operative time (130.3 ± 58.53, 121 ± 33.90 and 241.5 ± 45.27 min) and cumulative intraprocedural radiation dose (14.2 ± 6.36, 15.4 ± 12.17 and 72.8 ± 12.26 mGy) are reported in this paper for MED ± MEF, MEDS ± MEF and ME-TLIF, respectively. TELIGEN affords an expanded surgical field of view with unique engineered benefits that provide a promissing platform to enhance minimally invasive spine surgery.

Supracerebellar Infratentorial Keyhole Approach in Sitting Position Using 3-Dimensional Exoscope and Angled Endoscope for a Giant Pineal Tumor.

Pineal tumors are rare but surgically challenging due to their deep location and proximity to major veins and brainstem.1,2 Getting a biopsy along with an endoscopic third ventriculostomy is essential before surgical resection.3,4 The supracerebellar infratentorial approach provides direct symmetrical exposure of the pineal region inferior to the vein of Galen.5,6 3-Dimensional (3D) exoscopes are increasingly used due to better ergonomics, greater depth of field, and equivalent image quality of microscope. The endoscope provides angled optics to visualize hidden areas of tumor adherent to neurovascular structures, avoiding blind dissection. These become especially advantageous during suboccipital keyhole surgery in the sitting position, which averts both cerebellar retraction and frequent soiling of the endoscope. In this case of a giant pineal papillary tumor in a 16-year-old patient, we used both a 3D-exoscope and a 45-degree angled endoscope complementarily (Video 1). The tumor underwent straight-ahead internal decompression using an exoscope. Once some space became available, the angled endoscope was inserted to excise the tumor initially in the inferior aspect and then rotated toward either side to dissect the tumor from the basal veins of Rosenthal. Lastly, the superior pole stuck to the undersurface of the vein of Galen was gradually excised. There were no neurologic deficits. Histopathology was a high-grade papillary tumor. Magnetic resonance imaging confirmed gross total resection. This is probably the first report of a supracerebellar infratentorial keyhole approach for gross total resection of a giant pineal tumor, effectively using the better ergonomics and depth of field of a 3D exoscope along with angled optics provided by an endoscope, resulting in an excellent outcome.

Optimizing Disc and Cartilage Endplate Preparation in Full-Endoscopic Lumbar Interbody Fusion: An In-Depth Exploration of Surgical Instruments with a Technique Note and Narrative Review.

Full-endoscopic lumbar interbody fusion (FELIF) is a critical yet challenging procedure. However, extensive analyses of discectomy and cartilage endplate preparation techniques are limited. This can be attributed to the lack of universal protocols owing to diverse surgical practices and equipment preferences. Therefore, this narrative review presents a comprehensive overview of discectomy and cartilage endplate preparation techniques in FELIF. A literature search of the PubMed, Embase, and Google Scholar databases in December 2023 retrieved 490 studies, of which 53 met the predefined inclusion criteria, and 1373 patients were included in the analyses. Spinal endoscopic disc and cartilage endplate removal can be categorized into 2 main types: removal under direct endoscopic visualization and removal under radiographic guidance with the protection of a working sheath following the endoscope's removal. Removal under direct visualization ensures the safety and precision of the procedure. Radiographic guidance can enhance the efficiency of the removal process. Specially designed instruments can be utilized through the narrow working channels of spinal endoscopes for the scraping surgery. Moreover, many traditional spinal endoscopic instruments, through specific techniques and manipulations, can also aid in cartilage removal. The approaches and techniques vary significantly among physicians, but overall, these instruments and techniques aim to achieve a safe and efficient disc-scraping outcome. Thus, this review may offer a comprehensive guidance to surgeons in selecting the most efficient practices for FELIF. Uniform procedural protocols are needed to ensure broader adoption and standardized practice.

The Usefulness of the 3.1-mm-diameter 4K Rigid Endoscope for Intracerebral Hematoma Evacuation.

The indication for surgical intervention in spontaneous intracerebral hemorrhage remains controversial. Although many clinical trials have failed to demonstrate its efficacy over medical treatment, less invasive endoscopic treatment is expected to demonstrate its superiority. A novel endoscopic system for hematoma removal consisting of a 3.1-mm-diameter 4K high-resolution rigid endoscope was used.The system was used in eight cases of spontaneous intracerebral hemorrhage. It provided improved maneuverability of the surgical instrument while maintaining satisfactory image quality. The surgical goal was achieved in all cases without any complications, including perioperative rebleeding.Endoscopic hematoma removal using the 3.1 mm high-resolution endoscope is an alternative minimally invasive approach to spontaneous intracerebral hemorrhage with improved reliability.

Endoscopic Management of Chronic Subdural Hematoma Using a Novel Brain Retractor.

BACKGROUND: Endoscopic procedures are useful in chronic subdural hematoma especially when there are septations, solid/organized hematoma, and the presence of bridging or neovessels in the cavity. Visualizing the distal hematoma cavity by a rigid scope is challenging in large and curved ones due to the hindrance by the brain surface. Combining rigid endoscopy and brain retractor can overcome this limitation. METHODS: A retrospective study of 248 patients managed by endoscopic technique was performed and the relevant literature was reviewed. RESULTS: The brain retractor was used in all patients. Average operative time, subgaleal drainage duration, and hospital stay were 56 minutes, 3.1 days, and 4.6 days, respectively. The average preoperative Glasgow coma scale (GCS) score was 12, which improved to 14 and 15 in 223 and 23 patients, respectively at discharge. There were solid clots, septations, bridging vessels, curved hematoma cavities, rapid expansion of the brain after partial hematoma removal, and recurrences in 59, 52, 15, 49, 19, and 2 patients, respectively. There were 2 deaths, without any procedure-related mortality. CONCLUSIONS: Endoscope was very effective and safe in the management of chronic subdural hematoma, especially in about 51% patients with solid clots, septations, and bridging vessels which could have been difficult to treat by conventional burr hole. It can avoid craniotomy in such patients. Good visualization and complete hematoma removal were possible with the help of an endoscope and brain retractor in about 27% of patients which could have been difficult with a rigid endoscope alone.

Experience in endoscope choice for neuroendoscopic lavage for intraventricular hemorrhage of prematurity: a systematic review.

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.

Dynamic Workflow Proposal for Continuous Frameless Electromagnetic Neuronavigation in Rigid Neuroendoscopy.

BACKGROUND: Ventriculoscopic neuronavigation has been described in several articles. However, there are different ventriculoscopes and navigation systems. Due to these different combinations, it is difficult to find detailed neuronavigation protocols. We describe, step-by-step, a simple method to navigate both the trajectory until reaching the ventricular system, as well as the intraventricular work. METHODS: We use a rigid ventriculoscope (LOTTA, KarlStorz) with an electromagnetic stylet (S8-StealthSystem, Medtronic). The protocol is based on a modified or 3-dimensionally printed trocar for navigating the extraventricular step and on a modified pediatric nasogastric tube for the intraventricular navigation. RESULTS: This protocol can be set up in less than 10 minutes. The extraventricular part is navigated by introducing the electromagnetic stylet inside the modified or 3-dimensionally printed trocar. Intraventricular navigation is done by combining a modified pediatric nasogastric tube with the electromagnetic stylet inside the endoscope's working channel. The most critical point is to obtain a blunt-bloodless ventriculostomy while achieving perfect alignment of all targeted structures via pure straight trajectories. CONCLUSIONS: This protocol is easy-to-set-up, avoids head rigid-fixation and bulky optical-based attachments to the ventriculoscope, and allows continuous navigation of both parts of the surgery. Since we have implemented this protocol, we have noticed a significant enhancement in both simple and complex ventriculoscopic procedures because the surgery is dramatically simplified.

Cylinder tumor surgery in pediatric low-grade gliomas.

BACKGROUND: Periventricular pediatric low-grade gliomas (pLGG) present a surgical challenge due to their deep-seated location, accessibility, and relationship with the subcortical network connections. Minimally invasive parafascicular approaches with tubular brain retractors (port brain surgery) have emerged, in recent years, as an alternative to conventional microsurgical and endoscopic approaches for removal of periventricular tumors. OBJECTIVES: To describe the minimally invasive approach with tubular brain retractors for periventricular pLGG, its technique, applications, safety, and efficacy. METHODS: In this article, we describe the port brain surgery techniques for periventricular pLGG as performed in different centers, with different commercialized tubular retractor systems. Illustrative cases followed by a literature review are analyzed, with a detailed description of different approaches or techniques, comparing their advantages and disadvantages with contemporary microsurgical and endoscopic approaches. CONCLUSIONS: The port brain surgery with micro-exoscopic vision and endoscopic assistance, for the treatment of deep-seated lesions such as periventricular pLGG, is an alternative for achieving a functionally safe-gross total or subtotal-tumor resection, obtaining adequate tissue for pathological examination. This technique could offer a new dimension for a less-invasive, safe, and effective access to deep-seated tumors, offering the possibility to lower morbidity in experienced hands.

Endoscopic 5-Aminolevulinic Acid-Induced Fluorescence-Guided Intraparenchymal Brain Tumor Resection-Can the Endoscope Detect More Fluorescence Than the Microscope?

OBJECTIVES: Using a laboratory-based optical setup, we show that 5-aminolevulinic acid (5ALA) fluorescence is better detected using the endoscope than the microscope. Furthermore, we present our case series of fully endoscopic 5ALA-guided resection of intraparenchymal tumors. METHODS: A Zeiss Pentero microscope was compared with the Karl Storz Hopkins endoscope. The spectra and intensity of each blue light source were measured. Quantitative fluorescence detection thresholds were measured using a spectrometer. Subjective fluorescence detection thresholds were measured by 6 blinded neuro-oncology surgeons. Clinical data were prospectively collected for all consecutive cases of fully endoscopic 5ALA-guided resection of intraparenchymal tumors between 2012 and 2023. RESULTS: The intensity of blue light on the sample was greater for the endoscope than the microscope at working distances less than 20 mm. The quantitative fluorescence detection thresholds were lower for the endoscope than the microscope at both 30-/10-mm working distances. Fluorescence detection threshold was 0.65%-0.80% relative 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyranthe concentration (3.20 × 10-7 to 3.94 × 10-7mol/dm-3) for the microscope, 0.40%-0.55% relative concentrations (1.97 × 10-7 to 2.71 × 10-7mol/dm-3) for the endoscope at 30 mm, and 0.15%-0.30% relative concentrations (7.40 × 10-8 to 1.48 × 10-7mol/dm-3) for the endoscope at 10 mm. In total, 49 5ALA endoscope-assisted brain tumor resections were carried out on 45 patients (mean age = 41 years, male = 28). Greater than 95% resection was achieved in 80% of cases and gross total resection in 42%. Gross total resection was achieved in 100% of tumors in noneloquent locations. There was 1 new neurologic deficit. CONCLUSIONS: The endoscope provides enhanced visualization/detection of 5ALA-induced fluorescence compared with the microscope. 5ALA endoscopic-assisted resection of intraparenchymal tumors is safe and feasible.

Endoport-Assisted Endoscopic Surgery for Removal of Lateral Ventricular Tumors: Our Experience and Review of the Literature.

Background: Endoscopic surgery has emerged in recent years as an alternative to conventional microsurgical approaches for removal of intraventricular tumors. Endoports have enhanced tumor access and visualization with a significant reduction in brain retraction. Objective: To evaluate the safety and efficacy of endoport-assisted endoscopic technique for the removal of tumors from the lateral ventricle. Methods: The surgical technique, complications, and postoperative clinical outcomes were analyzed with a review of the literature. Results: Tumors were primarily located in one lateral ventricular cavity in all 26 patients, and extension to the foramen Monro and the anterior third ventricle was observed in seven and five patients, respectively. Except for three patients with small colloid cysts, all other tumors were larger than 2.5 cm. A gross total resection was performed in 18 (69%), subtotal in five (19%), and partial removal in three (11.5%) patients. Transient postoperative complications were observed in eight patients. Two patients required postoperative CSF shunting for symptomatic hydrocephalus. All patients improved on KPS scoring at a mean follow-up of 4.6 months. Conclusions: Endoport-assisted endoscopic technique is a safe, simple, and minimally invasive method to remove intraventricular tumors. Excellent outcomes comparable to other surgical approaches can be achieved with acceptable complications.

Keyhole Supraorbital-Eyebrow Approach for Resection of an Olfactory Groove Meningioma with Intraoperative Endoscopic Assistance.

The authors present the case of a 52-year-old male with a history of new-onset seizures who presented in status epilepticus. Computed tomography and magnetic resonance imaging demonstrated an olfactory groove mass. A keyhole supraorbital-eyebrow approach assisted with a microinspection tool was performed for tumor resection.1-5 A Simpson grade 2 tumor resection was achieved, and histopathology revealed a World Health Organization grade I olfactory groove meningioma. Postoperative and follow-up course has been unremarkable, with early postoperative imaging demonstrating no residual tumoral mass. The operative video highlights the advantages of using the microinspection tool for the visualization of deep lesions.

Additive Manufacturing for Personalized Skull Base Reconstruction in Endoscopic Transclival Surgery: A Proof-of-Concept Study.

BACKGROUND: Endoscopic transnasal transclival intradural surgery is limited by a high postoperative cerebrospinal fluid leak rate. The aim of this study was to investigate the role of three-dimensional printing to create a personalized, rigid scaffold for clival reconstruction. METHODS: Two different types of clivectomy were performed in 5 specimens with the aid of neuronavigation, and 11 clival reconstructions were simulated. They were repaired with polylactide, three-dimensional-printed scaffolds that were manually designed in a computer-aided environment based either on the real or on the predicted defect. Scaffolds were printed with a fused filament fabrication technique and different offsets. They were positioned and fixed either following the gasket seal technique or with screws. Postdissection radiological evaluation of scaffold position was performed in all cases. In 3 specimens, the cerebrospinal fluid leak pressure point was measured immediately after reconstruction. RESULTS: The production process took approximately 30 hours. The designed scaffolds were satisfactory when no offset was added. Wings were added during the design to allow for screw positioning, but broke in 30% of cases. Radiological assessment documented maximal accuracy of scaffold positioning when the scaffold was created on the real defect; accuracy was satisfactory when the predicted clivectomy was performed under neuronavigation guidance. The cerebrospinal fluid leak pressure point was significantly higher when the scaffold was fixed with screws compared with the gasket technique. CONCLUSIONS: In this preclinical setting, additive manufacturing allows the creation of customized scaffolds that are effective in reconstructing even large and geometrically complex clival defects.

Rigid versus flexible neuroendoscopy: a systematic review and meta-analysis of endoscopic third ventriculostomy for the management of pediatric hydrocephalus.

OBJECTIVE: Endoscopic third ventriculostomy (ETV), with or without choroid plexus cauterization (±CPC), is a technique used for the treatment of pediatric hydrocephalus. Rigid or flexible neuroendoscopy can be used, but few studies directly compare the two techniques. Here, the authors sought to compare these methods in treating pediatric hydrocephalus. METHODS: A systematic MEDLINE search was conducted using combinations of keywords: "flexible," "rigid," "endoscope/endoscopic," "ETV," and "hydrocephalus." Inclusion criteria were as follows: English-language studies with patients 2 years of age and younger who had undergone ETV±CPC using rigid or flexible endoscopy for hydrocephalus. The primary outcome was ETV success (i.e., without the need for further CSF diversion procedures). Secondary outcomes included ETV-related and other complications. Statistical significance was determined via independent t-tests and Mood's median tests. RESULTS: Forty-eight articles met the study inclusion criteria: 37 involving rigid endoscopy, 10 involving flexible endoscopy, and 1 propensity scored-matched comparison. A cumulative 560 patients had undergone 578 rigid ETV±CPC, and 661 patients had undergone 672 flexible ETV±CPC. The flexible endoscopy cohort had a significantly lower average age at the time of the procedure (0.33 vs 0.53 years, p = 0.001) and a lower preoperatively predicted ETV success score (median 40, IQR 32.5-57.5 vs 62.5, IQR 50-70; p = 0.033). Average ETV success rates in the rigid versus flexible groups were 54.98% and 59.65% (p = 0.63), respectively. ETV-related complication rates did not differ significantly at 0.63% for flexible endoscopy and 3.46% for rigid endoscopy (p = 0.30). There was no significant difference in ETV success or complication rate in comparing ETV, ETV+CPC, and ETV with other concurrent procedures. CONCLUSIONS: Despite the lower expected ETV success scores for patients treated with flexible endoscopy, the authors found similar ETV success and complication rates for ETV±CPC with flexible versus rigid endoscopy, as reported in the literature. Further direct comparison between the techniques is necessary.

Resection of intra- and paraventricular malignant brain tumors using fluorescein sodium-guided neuroendoscopic transtubular approach.

BACKGROUND: The requirement of brain retraction and difficulty in distinguishing the tumor demarcation are challenging in conventional approaches to intra- and paraventricular malignant tumors (IV-PVMTs). Tubular retractors can minimize the retraction injury, and fluorescein-guided (FG) surgery may promote the resection of tumors. Our aim is to evaluate the feasibility, safety, and effectiveness of fluorescein-guided endoscopic transtubular surgery for the resection of IV-PVMTs. METHODS: Twenty patients with IV-PVMTs underwent FG endoscopic transtubular tumor resection. Fluorescein sodium was administered before the dural opening. The intraoperative fluorescence staining was classified as "helpful" and "unhelpful" based on surgical observation. Extent of resection was assessed using postoperative magnetic resonance imaging. Karnofsky Performance Status (KPS) score was used to evaluate the general physical condition of patients. RESULTS: There were 9 glioblastomas, 4 anaplastic astrocytomas and 7 metastatic tumors. "Helpful" fluorescence staining was observed in 16(80%) of 20 patients. Gross total resection was achieved in 16(80%) cases, near-total in 3(15%) cases, and subtotal in 1 (5%) case. No intra- or postoperative complications related to the fluorescein sodium occurred. The median preoperative KPS score was 83, and the median KPS score 3-month after surgery was 88. CONCLUSION: FG endoscopic transtubular surgery is a feasible technique for the resection of IV-PVMTs. It may be a safe and effective option for patients with these tumors. Future prospective randomized studies with larger samples are needed to confirm these preliminary data.

First-in-Human Clinical Experience Using High-Definition Exoscope with Intraoperative Indocyanine Green for Clip Reconstruction of Unruptured Large Pediatric Aneurysm.

The operative exoscope is a novel tool that combines the benefits of surgical microscopes and endoscopes to yield excellent magnification and illumination while maintaining a comparatively small footprint and superior ergonomic features. Until recently, current exoscopes have been limited by 2-dimensional viewing; however, recently a 3-dimensional (3D), high-definition (4K-HD) exoscope has been developed (Sony-Olympus, Tokyo, Japan).1 Our group had previously described the first in-human experiences with this novel tool including microsurgical clipping of intracranial aneurysms. We have highlighted the benefits of the exoscope, which include providing an immersive experience for surgeons and trainees, as well as superior ergonomics as compared with traditional microsurgery.2 To date, exoscopic 3D high-definition indocyanine green (ICG) video angiography (ICG-VA) has not been described. ICG-VA, now a mainstay of vascular microsurgery, uses intravenously injected dye to visualize intravascular fluorescence in real time to assess the patency of arteries and assess clip occlusion of aneurysms.3,4 The ability to safely couple this tool with the novel exoscope has the potential to advance cerebrovascular microsurgery. Here, we present a case of a 11-year-old male with Alagille syndrome, pancytopenia, and peripheral pulmonary stenosis found to have a 12 × 13 × 7 mm distal left M1 aneurysm arising from the inferior M1/M2 junction. The patient was neurologically intact without evidence of rupture. In order to prevent catastrophic rupture, the decision was made to treat the lesion. Due to the patients underlying medical conditions including baseline coagulopathy, surgical management was felt to be superior to an endovascular reconstruction, which would require long-term antiplatelet therapy. Thus the patient underwent a left-sided pterional craniotomy with exoscopic 3D ICG-VA. As demonstrated in Video 1, ICG-VA was performed before definitive clip placement in order to understand flow dynamics with particular emphasis on understanding the middle cerebral artery outflow. Postoperatively, the patient remained at his neurologic baseline and subsequent imaging demonstrated complete obliteration of the aneurysm without any neck remnant. The patient continues to follow and remains asymptomatic and neurologically intact without radiographic evidence of residual or recurrence.