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.

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.

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.

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.

Flexible endoscopic assistance in the surgical management of vestibular schwannomas.

Endoscopic-assisted techniques have extensively been applied to vestibular schwannoma (VS) surgery allowing to increase the extent of resection, minimize complications, and preserve facial nerve and auditory functions. In this paper, we retrospectively analyze the effectiveness of flexible endoscope in the endoscopic-assisted retrosigmoid approach for the surgical management of VS of various sizes. The authors conducted a retrospective analysis on 32 patients who underwent combined microscopic and flexible endoscopic resection of VS of various sizes over a period of 16 months. Flexible endoscopic-assisted retrosigmoid approach was performed in all cases, and in 6 cases, flexible and rigid endoscopic control were used in combination to evaluate the differences between the two surgical instruments. The surgical results were additionally compared with a previous case series of 141 patients operated for VS of various sizes without endoscopic assistance. Gross-total resection was achieved in 84% of the cases and near-total resection was accomplished in the rest of them. Excellent or good facial nerve function was observed in all except one case with a preoperative severe facial palsy. Hearing preservation surgery (HPS) was attempted in 11 cases and accomplished in 9 (81.8%). A tumor remnant was endoscopically identified in the fundus of the IAC in all cases (100%). Endoscopic assistance increased the rate of total removal and no intrameatal residual tumor was seen at radiological follow-up. Comparative analysis with a surgical cohort of patients operated with the sole microsurgical technique showed a significative association between endoscopic assistance and intracanalicular extent of resection. Combined microsurgical and flexible endoscopic assistance provides remarkable advantages in the pursuit of maximal safe resection of VS and preservation of facial nerve and auditory functions, minimizing the risk of post-operative complications.

Assessing the surgical outcome of the "chopsticks" technique in endoscopic transsphenoidal adenoma surgery.

OBJECTIVE: The "chopsticks" technique is a 3-instrument, 2-hand mononostril technique that has been recently introduced in endoscopic neurosurgery. It allows a dynamic surgical view controlled by one surgeon only while keeping bimanual dissection. Being a mononostril approach, it requires manipulation of the mucosa of one nasal cavity only. The rationale of the technique is to reduce nasal morbidity without compromising surgical results and complication rates. There are, however, no data available on its results in endoscopic surgery (transsphenoidal surgery [TSS]) for pituitary adenoma. METHODS: The authors performed a cohort analysis of prospectively collected data on 144 patients (156 operations) undergoing TSS using the chopsticks technique with 3T intraoperative MRI. All patients had at least 3 months of postoperative neurosurgical, endocrinological, and rhinological follow-up (Sino-Nasal Outcome Test-20 [SNOT-20] and Sniffin' Sticks). The surgical technique is described, and the achieved gross-total resection (GTR) and extent of resection (EOR) together with patients' clinical outcomes and complications are descriptively reported. RESULTS: On 3-month postoperative MRI, GTR was achieved in 71.2% of patients with a mean EOR of 96.7%. GTR was the surgical goal in 122 of 156 cases and was achieved in 106 of 122 (86.9%), with a mean EOR of 98.7% (median 100%, range 49%-100%). There was no surgical mortality. At a median follow-up of 15 months (range 3-70 months), there was 1 permanent neurological deficit. As of the last available follow-up, 11.5% of patients had a new pituitary single-axis deficit, whereas 26.3% had improvement in endocrinological function. Three patients had new postoperative hyposmia. One patient had severe impairment of sinonasal function (SNOT-20 score > 40). The operation resulted in endocrine remission in 81.1% of patients with secreting adenomas. CONCLUSIONS: This study shows that the chopsticks technique confers resection and morbidity results that compare favorably with literature reports of TSS. This technique permits a single surgeon to perform effective endoscopic bimanual dissection through a single nostril, reducing manipulation of healthy tissue and thereby possibly minimizing surgical morbidity.

Purely neuroendoscopic resection of intraventricular tumors with an endoscopic ultrasonic aspirator.

Surgery for intraventricular tumors remains a controversial and evolving field, with endoscopic resection becoming more popular. We present a series of nine consecutive cases of purely endoscopic resection of intraventricular tumors with the aid of an ultrasonic aspirator specific for neuroendoscopy. Nine patients (five men, four women) aged 18-74 years (mean 43.7) underwent surgery. The most common symptom was headache. In all cases, magnetic resonance imaging showed single supratentorial intraventricular lesions (five lateral ventricle, four third ventricle). The average maximum diameter was 20.5 mm (range 11-42). Associated hydrocephalus was found in eight cases at diagnosis. Five patients underwent complete macroscopic resection. Three underwent subtotal resection and one underwent partial resection (two thirds of the tumor). The mean endoscopic procedure time was 70 min (37-209). The eight patients with associated hydrocephalus also underwent endoscopic septostomy to improve cerebral spinal fluid circulation, with one patient additionally requiring endoscopic third ventriculostomy and another requiring Monro foraminoplasty. One patient required ventriculoperitoneal shunting. The mean post-operative follow-up was 15.1 months (range 2-33). At the time of analysis, no patient showed recurrence or regrowth of the operated lesion. The histological diagnoses and degree of resection were three subependymomas with complete resection, three colloid cysts with two complete and one subtotal resection, one pilocytic astrocytoma with partial resection (approximately two thirds of the lesion), one epidermoid tumor with subtotal resection, and one central neurocytoma with subtotal resection. The endoscopic ultrasonic surgical aspirator can be a safe and effective tool for the removal of intraventricular tumors, even in firmer solid lesions.

Endoscope-Assisted Far Lateral Approach to the Craniovertebral Junction with Neuronavigation: A Cadaver Laboratory Experience.

The far lateral approach (FLA) is a technique performed nowadays to gain access to and remove intradural lesions located ventrolaterally to the brainstem and to the craniovertebral junction (CVJ).

Outcome of single-trajectory rigid endoscopic third ventriculostomy and biopsy in the management algorithm of pineal region tumors: a case series and review of the literature.

BACKGROUND: Tumors within the pineal region represent 1.5 to 8.5% of the pediatric brain tumors and 1.2% of all brain tumors. A management algorithm has been proposed in several publications. The algorithm includes endoscopic third ventriculostomy (ETV) and biopsy in cases presenting with hydrocephalus. In this series, we are presenting the efficacy of a single-trajectory approach for both ETV and biopsy. METHODS: Eleven cases were admitted to Alexandria main university hospital from 2013 to 2016 presenting with pineal region tumors and hydrocephalus. Mean age at diagnosis was 11 years (1-27 years). All cases had ETV and biopsy using rigid ventriculoscope through a single trajectory from a burr hole planned on preoperative imaging. Follow-up period was 7-48 months. RESULTS: All 11 cases presented with hydrocephalus and increased intracranial pressure manifestations. Histopathological diagnosis was successful in 9 out of 11 cases (81.8%). Three cases were germ-cell tumors, two cases were pineoblastomas, two cases were pilocytic astrocytomas, and two cases were grade 2 tectal gliomas. Five of the ETV cases (45.5%) failed and required VPS later on. Other complications of ETV included one case of intraventricular hemorrhage and a case with tumor disseminated to the basal cisterns. CONCLUSION: In our series, we were able to achieve ETV and biopsy through a single trajectory and a rigid endoscope with results comparable to other studies in the literature.

A new modified neuroendoscope technology to remove severe intraventricular haematoma.

BACKGROUND: Minimally invasive endoscopic haematoma evacuation is widely used in the treatment of intraventricular haemorrhage. However, its technique still has room for improvement. A new modified neuroendoscope technology (MNT) was used in this study and we explored its safety and efficacy in the treatment of severe acute intraventricular haemorrhage by comparing it with extraventricular drainage plus urokinase thrombolytic (EVD + UT) therapy. METHODS: The following parameters were compared between the MNT group and the control group: incision design, operation time, ICU monitoring time, ventricular drainage tube (VDT) placement time, post-operative drainage tube obstruction (PDTO) rate, post-operative complications rate, 6-month mortality and Glasgow Outcome Scale (GOS). RESULTS: A total of 85 patients were enrolled. The ICU monitoring times, VDT placement times, PDTO rate were shorter in the MNT group. Multivariable logistic regression identified that good medium-term outcome (GOS scores 4-5) was significantly associated with MNT applied (OR 1.017, 95% CI 1.005-1.029, p = 0.008), age under 65 years (OR 4.223, 95% CI, 1.322-17.109, p = 0.034) and pre-operation GCS scores more than 10 (OR 3.427, 95% CI 1.048-11.205, p = 0.040). CONCLUSION: MNT surgery for severe intraventricular haematoma evacuation is a safe and efficient new surgical option. This technique is minimally invasive and may be helpful to provide good outcomes for selected patients.

Endoscopic neuroendoscopy using a novel ventricular access port.

BACKGROUND: Hydrocephalus remains an important aspect of neurosurgical care and in select circumstances, the endoscopic third ventriculostomy (ETV) continues to remain an important treatment. In our initial experience of ETV using the commercially available plastic ventricular ports we found them both restrictive and expensive. Following this experience, we developed a stainless steel ventricular access port (VAP). We present our novel method of access involving this non-disposable ventricular port. METHOD: We have developed a series of custom-made, 316-grade stainless steel VAPs designed specifically for our ventricular endoscopes. Following a standard Burr-hole, cannulation of the lateral ventricle is performed inserting this port and removing the trocar allowing free access using a standard ventriculoscope without the requirement for disposable plastic ports. Since 2008 our unit has used a standard method of ventricular access using this device. We present our long-term experience of cases of endoscopic ventriculoscopy and ventriculostomy using this method of ventricular access. RESULTS: From December 2008 to January 2016, 56 patients underwent an endoscopic third ventriculostomy using the stainless steel ventricular port. Two 2 patients (3.6%) had a recorded complication in the form of minor self-limiting intraventricular haemorrhage. No cases of infection or mortality were noted in this patient series. CONCLUSION: We demonstrate our long-term experience with a non-disposable VAP for ventricular access. This method remains safe with results that are comparable to published series. We suggest this method may be a less expensive and safe alternative to standard disposable methods of ventricular access.

Skull Base Neuroendoscopic Training Model Using a Fibrous Injectable Tumor Polymer and the Nico Myriad.

The Myriad is an innovative, high precision tool for tumor resection, designed to work within narrow endoscopic corridors. Due to its application in technically demanding situations, the learning curve associated with its use might be extremely challenging and time-consuming.The authors describe the application of an already validated training model, the skull base injectable tumor model (ITM), to allow trainees to practice with the use of the Myriad during endoscopic skull base procedures.A formalin embalmed cadaveric head was used for technical assessment. Stratathane resin ST-504 derived polymer was injected to mimic skull base tumors and Myriad was used for tumor resection during different endoscopic procedures.An endoscopic endonasal transsphenoidal, a trans-planum trans-tuberculum, and a trans-clival approach have been performed after ITM injection. The Myriad was used for tumor debulking and blunt manipulation, qualitatively evaluating the technical challenges in performing the surgical dissection.Injectable tumor model demonstrates to be a valuable educational tool to train surgeons in the use of Myriad, potentially speeding up the learning curve in the acquirement of necessary technical skills in manipulating the instrument, even in case of demanding surgical situation.

Endoscopic endonasal transsphenoidal surgery using the iArmS operation support robot: initial experience in 43 patients.

Objective The intelligent arm-support system, iArmS, which follows the surgeon's arm and automatically fixes it at an adequate position, was developed as an operation support robot. iArmS was designed to support the surgeon's forearm to prevent hand trembling and to alleviate fatigue during surgery with a microscope. In this study, the authors report on application of this robotic device to endoscopic endonasal transsphenoidal surgery (ETSS) and evaluate their initial experiences. Methods The study population consisted of 43 patients: 29 with pituitary adenoma, 3 with meningioma, 3 with Rathke's cleft cyst, 2 with craniopharyngioma, 2 with chordoma, and 4 with other conditions. All patients underwent surgery via the endonasal transsphenoidal approach using a rigid endoscope. During the nasal and sphenoid phases, iArmS was used to support the surgeon's nondominant arm, which held the endoscope. The details of the iArmS and clinical results were collected. Results iArmS followed the surgeon's arm movement automatically. It reduced the surgeon's fatigue and stabilized the surgeon's hand during ETSS. Shaking of the video image decreased due to the steadying of the surgeon's scope-holding hand with iArmS. There were no complications related to use of the device. Conclusions The intelligent armrest, iArmS, seems to be safe and effective during ETSS. iArmS is helpful for improving the precision and safety not only for microscopic neurosurgery, but also for ETSS. Ongoing advances in robotics ensure the continued evolution of neurosurgery.

Endoscopic approach via the interhemispheric fissure: the role of an endoscope in a surgical case of multiple falcine lesions.

BACKGROUND: For treating a patient with multiple falcine and parasagittal lesions, we believe that it is beneficial to resect the maximum possible number of lesions during one operation, even if some lesions are asymptomatic. This practice can potentially reduce the total number of operations during a patient's lifetime. METHODS: We provide an introduction of a concurrent endoscopic approach via the interhemispheric fissure. CONCLUSIONS: Applying this endoscopic approach concurrently with conventional microscopic surgery can enable the safe resection of as many lesions as possible during one operation.

Augmented reality in intraventricular neuroendoscopy.

BACKGROUND: Individual planning of the entry point and the use of navigation has become more relevant in intraventricular neuroendoscopy. Navigated neuroendoscopic solutions are continuously improving. OBJECTIVE: We describe experimentally measured accuracy and our first experience with augmented reality-enhanced navigated neuroendoscopy for intraventricular pathologies. PATIENTS AND METHODS: Augmented reality-enhanced navigated endoscopy was tested for accuracy in an experimental setting. Therefore, a 3D-printed head model with a right parietal lesion was scanned with a thin-sliced computer tomography. Segmentation of the tumor lesion was performed using Scopis NovaPlan navigation software. An optical reference matrix is used to register the neuroendoscope's geometry and its field of view. The pre-planned ROI and trajectory are superimposed in the endoscopic image. The accuracy of the superimposed contour fitting on endoscopically visualized lesion was acquired by measuring the deviation of both midpoints to one another. The technique was subsequently used in 29 cases with CSF circulation pathologies. Navigation planning included defining the entry points, regions of interests and trajectories, superimposed as augmented reality on the endoscopic video screen during intervention. Patients were evaluated for postoperative imaging, reoperations, and possible complications. RESULTS: The experimental setup revealed a deviation of the ROI's midpoint from the real target by 1.2 ± 0.4 mm. The clinical study included 18 cyst fenestrations, ten biopsies, seven endoscopic third ventriculostomies, six stent placements, and two shunt implantations, being eventually combined in some patients. In cases of cyst fenestrations postoperatively, the cyst volume was significantly reduced in all patients by mean of 47%. In biopsies, the diagnostic yield was 100%. Reoperations during a follow-up period of 11.4 ± 10.2 months were necessary in two cases. Complications included one postoperative hygroma and one insufficient fenestration. CONCLUSIONS: Augmented reality-navigated neuroendoscopy is accurate and feasible to use in clinical application. By integrating relevant planning information directly into the endoscope's field of view, safety and efficacy for intraventricular neuroendoscopic surgery may be improved.

Simultaneous combination of electromagnetic navigation with visual evoked potential in endoscopic transsphenoidal surgery: clinical experience and technical considerations.

OBJECTIVE: The combination of electromagnetic navigation with continuous monitoring techniques allows for the best available anatomic and real-time functional intraoperative monitoring. Methodological aspects and technical adaptations for this combination of methods and the results from 19 patients with tumors in the pituitary region are reported. METHODS: We retrospectively identified 19 patients who were treated with transsphenoidal surgery using high-resolution endoscopy (eTSS) at our hospital between June 2015 and June 2016. All patients underwent surgery under electromagnetic navigation with visual evoked potential (VEP) monitoring. The cases were reviewed for information on disease, and the distance between the patient tracker and emitter was measured. RESULTS: In 19 patients, 17 had pituitary adenomas, 1 had a Rathke cleft cyst, and 1 had an arachnoid cyst. The optimal distance between the patient tracker and emitter was 20-25 cm. VEP monitoring could be performed with unaffected recording quality under electromagnetic navigation. Also we were able to perform the registration and eTSS at this distance using both navigation and VEP monitoring. CONCLUSIONS: We performed eTSS for pituitary tumor by simultaneously using electromagnetic navigation and VEP. The optimal distance between the emitter and tracker minimizes VEP monitoring noise and allows accurate electromagnetic navigation.

Endoscopic third ventriculostomy: A historical review.

BACKGROUND: Endoscopic third ventriculostomy (ETV) has become one of the most common neuroendoscopic procedures. METHODS: In this article, we will review the major milestones in the history of ETV development from its early use by Walter Dandy to the techniques currently employed with advanced technology. CONCLUSIONS: ETV has become an important technique in the armamentarium of the neurosurgeon. From a meager beginning with few applications, our knowledge of long-term outcomes has evolved. ETV has a rich history and more recently, has had a renewed interest in its use. Our current understanding of its indications is growing and is based on a century of development through trial and error.

Intracranial Enterogenous Cysts Close to the Brainstem Treated Through the Nerve Endoscope.

Enterogenous cysts (ECs) are rare, inborn lesions of central nervous system, which mostly occurred in the ventral side of the spinal cord as well as common in children; adult intracranial cysts are rare. Although the morbidity of intracranial ECs is quite low, we also can make a preliminary diagnosis of those patients with the help of imaging examination. In this article, we introduced 1 case of ECs ventral to the brainstem, which present images on magnetic resonance imaging as hypointense lesions on T1-weighted and high-intensity mass on T2-weighted image. In consideration of the difficulty of the surgical approach and the surgical visual field exposure, we use microscope and nerve endoscope to design personalized surgical approach to minimize the surgical injury. Pathologic examination showed that it was typical EC. Not only is the location extremely rare, but also the surgical method is uncommon in this disease. We not only study the intracranial ECs' manifestations, but also discuss the surgical approach and the application of nerve endoscope of our choice,which aims to provides a new surgical therapeutic approach for these lesions.