Use Of Neuronavigation Research Articles

Usefulness of Neuronavigation During Cranial Surgery

Background: Neuronavigation helps neurosurgeons by providing intraoperative three dimensional (3D) view of CT/MRI of the patients thus helping the surgeon in different steps of surgery. With the objective to evaluate the usefulness of neuronavigation in early years after installment, this study was conducted at a tertiary care center in Nepal. 
 Methodology: This is a prospective analytical study, where all the consecutive cases of the neurosurgical cranial cases using frameless stereotactic (Medtronics stealth station 7), were considered during May 2014 to March 2017. All the lesions were categorized according to the location and were evaluated using the Image guided surgery (IGS) score. Analysis was done using stratification and percentage system. 
 Result: There were total 122 cases operated using neuronavigation during the study period, with ages ranged between 5 to 83 years with mean age 38.32(SD16.09) years. 57.4% were male and 42.6% were female. Overall IGS scoring of the neuronavigation in the different location showed irreplaceability in 100% cases of convexity, ganglionic/ deep seated/ ventricle and brain stem lesion; however, it was more useful than conventional methods in 70.37% of lobar cases. Similarly, overall IGS scoring of neuronavigation in the different type of lesions showed irreplaceable in 80% of meningiomas, and 41.17% of gliomas; however, was more useful than conventional methods in 56.86% of gliomas 
 Conclusion:Use of neuronavigation seems to be irreplaceable for planning and raising flaps, in cases of convexity lesions and most of the cases of lobar and ganglionic/ deep seated leasions.

Transsylvian, Carotid-Oculomotor Triangle Approach for Resection of a Rapidly Enlarging Midbrain-Pontine Cavernous Malformation: 3-Dimensional Operative Video.

Cavernous malformations (CM) of the anterior midbrain are best reached through an orbitozygomatic (OZ) approach with removal of the orbital rim and wide Sylvian fissure dissection. Our surgical video demonstrates this approach to resect a ruptured CM in a 36-yr-old woman who presented with headaches, left face and left arm paresthesias/weakness, and right-sided partial oculomotor nerve (CN III) palsy. Initial magnetic resonance imaging (MRI) showed a midbrain CM, and the patient was managed conservatively. However, 1 wk later, she presented again with worsened left arm and leg weakness and complete CN III palsy. Seven Tesla MRI demonstrated a larger hematoma, and the CM with new mass effect and upper pons extension. The patient underwent a right modified OZ craniotomy and Sylvian fissure split under guidance of intraoperative neuronavigation and with neuromonitoring. The carotid-oculomotor triangle and the Liliequist membrane were dissected to access the midbrain, and CN III was identified and followed posteriorly to the midbrain. Confirmed with neuronavigation, a longitudinal incision of the midbrain was performed, and the CM was encountered. The hematoma and CM were debulked and removed in a piece-meal fashion, leaving hemosiderin-stained brain intact to prevent unnecessary additional damage to the midbrain. Postoperative MRI confirmed gross-total resection, and the patient's weakness recovered substantially. In this video, we demonstrate that the brainstem is no longer forbidden surgical territory, and show how the use of neuronavigation for surgical planning, positioning, and approach, in addition to the understanding of safe entry zones and meticulous microsurgical technique have made safe and effective surgery on the brainstem possible.

New technics for removal of intradural spinal tumours

Introduction. Neuronavigation is a computer-assisted technology based on pre- and intraoperative images that permit neurosurgeons to have a better approach of the brain and intradural spinal tumors. The neuronavigation systems have been a significant progress in neurosurgery. These systems allow neurosurgeons to evaluate surgical risks, select the best interventional method, localize better the tumors in order to improve the accuracy of the resection and decide on the optimal trajectory for the surgical procedure, resulting in decreased patient morbidity and mortality.
 Material: Spinal cord tumors are rare and uncommon lesions. Their growth result in compression of the spinal cord, which can cause severe neurologic deficits such as limb dysfunction, motor and sensation loss with the possibility of leading to death. We present o short report of a study publicated by Stefini et al. in 2018 regarding the use of neuronavigation for removal of intradural spinal tumors.
 Conclusion: The benefits of using neuronavigation in resection of the intradural spinal tumors include decreased risk of bad localization of the tumor, minimal invasive surgery technique and reduction of bone removal.

Comparison of Complication and Revision Rates After Frontal Versus Parietal Approach for Ventricular Shunt Placement in Idiopathic Normal Pressure Hydrocephalus

Ventricular shunts are most commonly placed via a frontal or parietal approach. However, there is a paucity of data comparing complication and revision rates associated with these approaches in the idiopathic normal pressure hydrocephalus (iNPH) population. Patients with iNPH treated with ventricular shunting between 2001 and 2017 at our institution were included for analysis. Patient characteristics, catheter accuracy, and incidence of revision were determined from the medical record. Catheter accuracy was determined using axial computed tomography imaging and classified as grade 1, 2, or 3 based on location of the catheter tip. There were 348 patients included for analysis with 266 (76.4%) and 82 (23.6%) receiving a frontal versus parietal shunt, respectively. Patients undergoing the parietal approach were more likely to receive a programmable valve (37.8% vs. 25.2%; P= 0.026). Neuronavigation was used more frequently for patients undergoing the parietal approach (26.8% vs. 4.1%; P < 0.001); however, a minority of cases used neuronavigation in general (9.5%). There was no difference in catheter accuracy between the 2 approaches and no difference in catheter accuracy with the use of neuronavigation. The overall revision rate was 21.0%, and there were no differences in the incidence of revisions between the frontal and parietal approaches (21.8% vs. 18.3%, respectively; P= 0.495). There were no differences in revision subtypes between the approaches. These results suggest that the type of approach for shunting may not have a significant impact on complication and revision rates in patients with iNPH, and either approach is a reasonable first-line option.

Real-time neuronavigation feedback in concurrent TMS-fMRI

Introduction: Maintaining correct coil position is essential in transcranial magnetic stimulation (TMS). While neuronavigation and operator surveillance are available in typical therapy settings, concurrent TMS-fMRI experiments have to rely on positioning outside the MRI scanner without continuous verification throughout the session. Thus, subject motion during the TMS-fMRI experiment is usually unaccounted for and negatively affects results. Here, we present a new setup that (1) enables the use of neuronavigation inside the MRI scanner and (2) includes a real-time motion feedback system that allows subjects to correct their head positioning.

Neuronavigation-assisted surgical treatments for medically refractory epilepsy: Single-hospital experience with 4 surgical approaches

ObjectiveSurgical treatment should be considered for patients with medically refractory epilepsy, and neuronavigation may benefit and reduce the technical difficulties during surgery. In this study, we aimed to report our single-hospital experience of incorporating neuronavigation for treating patients with medically refractory epilepsy using 4 types of surgery. Patients and methodsPatients who were diagnosed as medically refractory epilepsy and received neuronavigation-assisted surgery were included in this retrospective analysis. The type of surgery was decided by the surgery committee after careful evaluation and discussion, including temporo-parietal-occipital (TPO) disconnection, anterior subtotal callosal section, functional hemispherectomy and resection of the epileptogenic zone(s). Postoperative seizure outcome at the last visit was evaluated using Engel classification. ResultsA total of 173 patients with medically refractory epilepsy who were treated surgically under the assistance of neuronavigation were included. The majority type of surgery was resection of epileptic zone, n = 104 (60.12%). An excellent seizure outcome, Engel Class I was found in 50.86% of the patients, followed by 23.12% patients with a good outcome of Engel Class II. ConclusionOverall more than half of the patients could have excellent seizure outcome of Engel Class I, the postoperative complications were manageable. These results indicated that the applicability of neuronavigation, and the use of neuronavigation provides good efficacy and safety for all kinds of surgical procedures for patients with medically refractory epilepsy.

Neuro-navigation assisted pre-psoas minimally invasive oblique lumbar interbody fusion (MI-OLIF): New roads and impediments.

Minimally invasive spine-oblique lumbar interbody fusion (MIS-OLIF) has emerged as a novel anterolateral, retroperitoneal, "pre-psoas" approach for lumbar interbody fusion for degenerative spinal instability, as well as for correction of deformity in patients without severe canal stenosis. In the last decade, the technique has gained popularity owing to several advantages like the minimal blood loss, minimal tissue dissection, preservation of posterior tension bands, better biomechanical strength, provision of mechanical stability to the lumbar spine, and a larger footprint of the implant, associated with it. It, thus, maximises load bearing on the cortical bone, and provides a better lordotic correction of the lumbar spine. The armamentarium is further boosted by the use of neuro-navigation and neuro-monitoring tools, thereby improving the surgical outcome. The clinical indications of MIS-OLIF and various fixation methods [lateral lumbar fixation (LLF) and percutaneous posterior pedicle fixation (PPF)] are discussed. The summary of the 15 patients on whom the technique was utilized, are discussed. The patients' demographics, clinical history and neurological examination data, pre- operative Oswestry disability index (ODI) and visual analogue scale (VAS) score, intraoperative surgical details and postoperative follow up clinical as well as radiological data were assessed. Complications, readmissions, length of stay, estimated blood loss, surgical time and surgical outcome were also recorded. 11 cases had grade 1 spondylolisthesis and 4 had grade 2 spondylolisthesis. One patient had both grade I and II spondylolisthesis at different levels. 13 patients had improvement in mechanical back pain and neurogenic claudication. Two patients had improvement in back pain but one-sided limb radiculopathy persisted, which was treated conservatively. The mean pre-operative ODI score was 35 ± 6.1, which improved to 14.6 ± 4.1 at follow-up (range of follow-up: 1 to 10 months; mean 5.7 ± 3.3 months]. The mean pre-operative VAS score was 7 ± 0.7, which improved to 3.3 ± 0.4 at follow-up. The MIS-OLIF technique at the L2-L5 levels has shown encouraging early surgical outcomes with a good fusion rate and rapid recovery. While utilizing the unfamiliar oblique trajectory, the use of navigation can guide the surgeon in real time and also help in reducing the radiation exposure.

Flat Panel Detector Computed Tomography−Guided Placement of External Ventricular Drains Using the BrainLAB Headband and Precalibrated Disposable Stylet Instrument: A Cadaveric Feasibility Study

The standard freehand method for the insertion of external ventricular drains (EVDs) is associated with high rates of incorrect placement. Use of neuronavigation has been shown to reduce the rates of inaccurately positioned EVDs. We present a novel neuronavigation-based approach for EVD placement using flat panel detector computed tomography (FDCT) imaging. Four cadaveric heads were used for neuronavigated placement of EVDs using the BrainLAB reference headband in combination with laser surface registration and the precalibrated disposable stylet. In 2 cases, conventional multislice CT imaging was performed to reference neuronavigation. In the other 2 cases, preprocedural imaging was performed with FDCT. After inserting the EVDs, all heads were examined again with the identical imaging method as used before the procedure, followed by evaluation of catheter position. Our data demonstrate that FDCT imaging provides adequate image quality for referencing neuronavigation and performing navigated neurosurgery. All EVDs showed an optimal position in the ipsilateral frontal horn. Use of a BrainLAB reference headband combined with laser surface registration and the precalibrated disposable stylet affords the advantage of not requiring rigid fixation in a clamp. Our presented method is fast, accurate, and easy to use. Furthermore, this study is the first to demonstrate that navigated neurosurgery can be performed on the basis of FDCT imaging.

The oxymoron of image-guided resection in 3 T MRI-negative extratemporal epilepsy: Technique and postoperative results

ObjectiveWe share our experience with extratemporal MRI-negative epilepsies that received “image-guided” resection with the use of neuronavigation after invasive presurgical video-EEG monitoring. We describe and discuss our technique of image generation, navigation system registration, and surgical resection. In addition, we evaluate seizure outcome with respect to the preoperatively planned versus achieved resection. Patients and MethodsSeven patients with 3 T MRI-negative extratemporal epilepsy received navigation-guided resective surgery. The resection plan was based on electrophysiological data from intracranial EEG recordings. For each case a resection segment was created in the neuronavigation device in a systematic manner. We compared the preoperatively planned segment to the achieved resection and looked for correlation with postoperative seizure outcome according to Engel classification, at last follow-up (mean 2.4 years, range 1–4 years). ResultsMean volume of planned resections was 23.8 ± 15.3 cm3 and of achieved resections 17 ± 10.4 cm3. There was complete overlap with planned resection in 4 patients and partial overlap in 3. Postoperative seizure outcome was class I in 4 patients (57%), IIIA in 1 patient and IVB in 2 patients. Three patients reached seizure-freedom (Engel IA). Volume of planned resection, volume difference of planned versus achieved resection and level of overlap (complete versus partial) did not significantly correlate to seizure outcome. ConclusionThe use of neuronavigation for planning and executing a tailored resection in MRI-negative extratemporal epilepsy is elaborate but can be an effective procedure.

Radiological "Teddy Bear" Sign on CT Imaging to Aid Internal Carotid Artery Localization in Transsphenoidal Pituitary and Anterior Skull Base Surgery.

Objectives Internal carotid artery (ICA) injury remains a rare but potentially fatal complication of transsphenoidal pituitary or anterior skull base surgery. Preoperative imaging must be scrutinized to minimize risk. On axial computed tomography (CT), the protrusions of the ICAs into the sphenoid resemble a "teddy bear." This article aims to describe the sign, its grading system (0-2) and quantify its presence. Design Retrospective review of preoperative CT imaging. Setting Tertiary referral center in the United Kingdom. Participants One hundred patients who underwent endoscopic transsphenoidal surgery for pituitary disease were enrolled. Main Outcome Measure The presence and grading of the "teddy bear" sign were assessed on preoperative CT imaging. Results A grade 2 (strongly positive) "teddy bear" sign was identified in 40% at the level of the superior pituitary fossa, 78% at the inferior pituitary fossa, and 59% at the clivus. A grade 1 (intermediate) sign was seen in 23.5, 7.5, and 10% of cases, respectively. In 5% of cases, the sign was grade 0 at all levels-indicating poor intraoperative localization of the ICA. Conclusion The "teddy bear" sign is a useful preoperative tool for identification of anatomy predisposing patients to a higher risk of ICA injury. Those patients who have an absent or grade 0 "teddy bear" sign require extra care to ensure intraoperative localization of the ICAs which may include the use of neuronavigation or a Doppler probe. A grade 2 sign predicts good intraoperative localization of the ICA intraoperatively to inform the safe lateral limit of sellar bone resection.

Surgical Management of Giant Intracranial Meningioma: Operative Nuances, Challenges, and Outcome.

The giant intracranial meningioma (GIM) constitutes a different spectrum of brain tumors that invade the vital neurovascular structures, which makes the primary mode of treatment, surgery, a technically challenging one. The surgery for GIM is unique because of the large size of the tumor, prominent vascularity, entangling and limited visualization of various neurovascular structures, and severe cerebral edema. This study reports the authors surgical experience of 80 GIM cases, the operative challenges and surgical outcome. A retrospective analysis of 80 patients with histologically proven meningioma (≥5 cm) who underwent surgical treatment at Louisiana State University Health Sciences Center (Shreveport, Louisiana, USA) over a 20-year period (1995-2015) is presented. The clinical and radiologic data were collected from the hospital database. The tumors were categorized into histologic groups according to World Health Organization (WHO) classification. The relevant statistical analysis of the study was conducted using SPSS software, version 22.0. The study included 27 male patients (33.8%) and 53 female patients (66.3%). The mean age of the cohort was 56 years (56.3±16.1). The mean size of the tumor was 56.4 ±4 mm with a range from 50 mm to 84 mm. Skull base was the most common location of GIM (57 patients, 71.3%). Simpson grade 1 excision was achieved in 9 patients (11.3%), whereas grade 2 excision was achieved in 57 patients (71.3%); 80% of the tumors belonged to WHO grade 1. The operative mortality was seen in 4 patients (5%). Regression analysis showed that age, sex, location of the tumor, neuronavigation, Simpson grade of excision, and histology of tumor were the factors that significantly affected the recurrence-free survival (RFS). The surgery for GIM is unique in different ways. As surgery for GIM is formidable, radiologic characteristics can be useful adjuncts for planning an effective and safe surgical strategy. The factors such as young age, male sex, use of neuronavigation, and skull base location positively influenced RFS, whereas Simpson grade 3 or 4 and poor histologic grade adversely influenced RFS. A careful preoperative evaluation, understanding of the risk factors, effective surgical approach, and judicious use of intraoperative adjuncts are the key factors with pivotal roles in GIM resection.

Three-Dimensional, computer simulated navigation in endoscopic neurosurgery.

In order to address the pre- and perioperative need for visualization and prediction of patient-specific anatomy for surgical planning, endoscopic neurosurgeons have increasingly relied on computerized navigation devices to guide their surgical approaches. This manuscript aims to review: 1) the use of neuronavigation in endoscopic neurosurgery for pre-operative planning, 2) the intraoperative advantages of neuronavigation in endoscopic neurosurgery, and 3) the effects of navigation guidance on operative time, registration accuracy, brain shift, and avoidance of complications. Limitations of the current neuroendoscopic navigation literature will be discussed. We conducted a search using PubMed-MEDLINE; the keywords "stereotactic navigation AND endoscopic surgery" and "simulation AND endoscopic neurosurgery". 36 studies were identified that addressed the use of neuronavigation in endoscopic neurosurgery. These studies were then further analyzed for topics relevant to computerized neuroendoscopy and reviewed for the purposes of this article. Three-dimensional, frameless neuronavigation systems are useful in endoscopic neurosurgery to assist in the pre-operative planning of potential trajectories and to help localize the pathology of interest. Neuronavigation appears to be accurate to < 1-2 mm without issues related to brain shift. Further work is necessary in the investigation of the effect of neuronavigation on operative time, cost, and patient-centered outcomes.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Surgical Techniques and Technologies for the Management of Patients With Nonfunctioning Pituitary Adenomas.

Numerous technological adjuncts are used during transsphenoidal surgery for nonfunctioning pituitary adenomas (NFPAs), including endoscopy, neuronavigation, intraoperative magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) diversion, and dural closure techniques. To generate evidence-based guidelines for the use of NFPA surgical techniques and technologies. An extensive literature search spanning January 1, 1966, to October 1, 2014, was performed, and only articles pertaining to technological adjuncts for NFPA resection were included. The clinical assessment evidence-based classification was used to ascertain the class of evidence. Fifty-six studies met the inclusion criteria, and evidence-based guidelines were formulated on the use of endoscopy, neuronavigation, intraoperative MRI, CSF diversion, and dural closure techniques. Both endoscopic and microscopic transsphenoidal approaches are recommended for symptom relief in patients with NFPAs, with the extent of tumor resection improved by adequate bony exposure and endoscopic visualization. In select cases, combined transcranial and transsphenoidal approaches are recommended. Although intraoperative MRI can improve gross total resection, its use is associated with an increased false-positive rate and is thus not recommended. There is insufficient evidence to recommend the use of neuronavigation, CSF diversion, intrathecal injection, or specific dural closure techniques. The full guidelines document for this chapter can be located at https://www.cns.org/guidelines/guidelines-management-patients-non-functioning-pituitary-adenomas/Chapter_6. CSF, cerebrospinal fluidNFPA, nonfunctioning pituitary adenoma.

Insular gliomas and the role of intraoperative assistive technologies: Results from a volumetry-based retrospective cohort

IntroductionIn the field of Glioma surgery, there has been an increasing interest in the use of assistive technologies to overcome the difficulty of preserving brain function while improving surgical radicality. In most reports, tumor localization has seldom been considered a variable and the role of intraoperative adjuncts is yet to be determined for gliomas of the insula. ObjectivesTo evaluate the efficacy of fluorescence-guided resection with 5-ALA, intraoperative neurophysiological monitoring (IOM), neuronavigation, and tractography in the Extent of Resection (EOR), functionality scores, overall survival (OS) and progression-free survival (PFS) in a retrospective cohort of insular gliomas. MethodsWe reviewed all cases of insular tumors operated on at the Department of Neurosurgery, University Hospital of Tübingen − Germany, between May 2008 and November 2013. EOR was determined by volumetric analysis. Mann Whitney, Chi-square and Kaplan Meier functions were used for assessment of each technology’s effect on primary and secondary outcomes. Results28 cases (18 men (64%) and 10 women (36%); median age at diagnosis: 52.5 years, range 12 − 59) were considered eligible for analysis. High grade and low grade gliomas accounted for 20 (71%) and 8 (29%) cases, respectively. The most used technologies were IOM (64%) and Neuronavigation (68%). 5-ALA was the only technique associated with EOR ≥90% (p=0.05). Tractography determined improvement in the Karnofsky Performance Scale (50% vs. 5% cases improved, p=0.02). There was a positive association between the use of neuronavigation and overall survival (23 vs. 27.4 months, p=0.03), but the use of 5-ALA was associated with shorter OS (34.8 vs. 21.1 months, p=0.01) and PFS (24.4 vs. 11.8, p=0.01). ConclusionsWe demonstrate for the first time that for insular gliomas 5-ALA plays a role in achieving higher EOR, although this technology was associated with poor OS and PFS; also tractography and neuronavigation can be of great importance in the treatment of insular gliomas as they determined better functionality and OS in this study, respectively. Prospective studies with a more prominent sample and proper multivariate analysis will help determine the real benefit of these adjuncts in the setting of insular gliomas.

Endoscopic Versus Stereotactic Procedure for Pineal Tumor Biopsies: Focus on Overall Efficacy Rate

The management of pineal region tumors depends on the histologic subtypes. Two minimally invasive techniques are available: endoscopic intraventricular biopsies and stereotactic biopsies. The recent Southampton and Lille series are the largest endoscopic and stereotactic series of pineal region tumors reporting both diagnosis rate and accuracy rate, respectively; we elaborated on these results in the light of other recent studies. We compared the Southampton endoscopic series with the Lille series, reflecting our 25-year experience of stereotactic biopsies, and the metadata of the literature for both approaches, as reported in the 2013 Report of the French-Speaking Society of Neurosurgery on tumors of the pineal region. The results of the Southampton series match the endoscopic literature, in particular regarding the diagnosis rate (81.2%) and the perioperative morbidity (25.0%), and provide a rarely reported accuracy rate (78.6%), giving access to the overall efficacy rate (63.8%). The results of the Lille series match the stereotactic literature and show better results than endoscopic biopsies concerning the diagnosis rate (98.9%), accuracy rate (100%), resulting overall efficacy rate (98.9%), and perioperative morbidity (6.4%). The Southampton and Lille series provide a unique opportunity to compare the overall efficacy rates of endoscopic and stereotactic biopsies, respectively. The stereotactic approach is safer and more effective for biopsies of pineal region tumors. To improve the safety and reliability of endoscopic biopsies, various methods have to be evaluated: alternative burr-hole strategies, use of neuronavigation, and a combination of flexible and rigid endoscopes.

Optimizing ventriculoperitoneal shunt placement in the treatment of idiopathic intracranial hypertension: an analysis of neuroendoscopy, frameless stereotaxy, and intraoperative CT.

Cerebrospinal fluid shunting can effectively lower intracranial pressure and improve the symptoms of idiopathic intracranial hypertension (IIH). Placement of ventriculoperitoneal (VP) shunts in this patient population can often be difficult due to the small size of the ventricular system. Intraoperative adjuvant techniques can be used to improve the accuracy and safety of VP shunts for these patients. The purpose of this study was to analyze the efficacy of some of these techniques, including the use of intraoperative CT (iCT) and frameless stereotaxy, in optimizing postoperative ventricular catheter placement. The authors conducted a retrospective review of 49 patients undergoing initial ventriculoperitoneal shunt placement for the treatment of IIH. The use of the NeuroPEN Neuroendoscope, intraoperative neuronavigation, and iCT was examined. To analyze ventricular catheter placement on postoperative CT imaging, the authors developed a new grading system: Grade 1, catheter tip terminates optimally in the ipsilateral frontal horn or third ventricle; Grade 2, catheter tip terminates in the contralateral frontal horn; Grade 3, catheter terminates in a nontarget CSF space; and Grade 4, catheter tip terminates in brain parenchyma. All shunts had spontaneous CSF flow upon completion of the procedure. The average body mass index among all patients was 37.6 ± 10.9 kg/m2. The NeuroPEN Neuroendoscope was used in 44 of 49 patients. Intraoperative CT scans were obtained in 24 patients, and neuronavigation was used in 32 patients. Grade 1 or 2 final postoperative shunt placement was achieved in 90% of patients (44 of 49). In terms of achieving optimal postoperative ventricular catheter placement, the use of iCT was as effective as neuronavigation. Two patients had their ventricular catheter placement modified based on an iCT study. The use of neuronavigation significantly increased time in the operating room (223.4 ± 46.5 vs. 190.8 ± 31.7 minutes, p = 0.01). There were no shunt infections in this study. The use of iCT appears to be equivalent to the use of neuronavigation in optimizing ventricular shunt placement in IIH. Additionally, it may shorten operating room time and limit overall costs.

Utility of Neuronavigation in Intracranial Meningioma Resection: A Single-Center Retrospective Study

In this study, we validate the utility of navigation in intracranial meningioma excision and evaluate the effectiveness of image guidance surgery based on clinical outcome, extent of resection, and recurrence-free survival (RFS). Information related to clinical history, use of neuronavigation, neuroimaging, microsurgical dissection, and outcomes of 517 consecutive cases with meningiomas between January 1995 and June 2015 was collected retrospectively. A Cox proportional hazards regression model was used to determine independent predictors of RFS. In this study, overall recurrence rate after tumor excision with or without neuronavigation was 17.7% and 31.2%, respectively (P= 0.03). Based on neuronavigation use, RFS of the patients with meningiomas in different locations also varied significantly (skull base; with, 110 months vs. without, 157 months; P= 0.02). The median RFS for patients operated on with or without use of neuronavigation during resection of tumors was 167 and 97 months, respectively, (log-rank P=0.0001). In Cox regression multivariate analysis, use of neuronavigation (P=0.0001), gross total resection (Simpson grade I-II; P= 0.001), and World Health Organization grade I tumor (P= 0.0001) were revealed as significant predictors of RFS. In addition, mean blood loss (P= 0.005) and average length of stay (P= 0.008) in the hospital were significantly reduced and performance status was improved using neuronavigation during resection of meningiomas. Interactive surgical navigation is a useful tool in the operative management of intracranial meningiomas to decrease recurrence rate, blood loss, and length of stay, and to improve RFS and performance status. Therefore, use of neuronavigation should be ensured during resection of intracranial meningiomas.

The Use of Neuronavigation with Vasular Microdoppler in Transsphenoidal Pituitary Surgery

Object: To evaluate the use of neuronavigation with vascular micro-doppler in transsphenoidal pituitary surgery. Methods: 141 cases having done transsphenoidal pituitary surgery are evaluated from 2005 to 2014. Fluoroscopy was used in 69 cases and vascular micro-doppler with neuronavigation were used in 72 cases. Results: Transsphenoidal surgery has a lot of risks due to sella’s deep location, and position of the carotid artery and the optic nerve. Clasically the fluoroscopy and microscopic anatomical markers were used in order to minimize the risk of carotid artery and optic nerve damage. Additional devices such as neuronavigation and vascular micro-doppler are needed to decrease the morbidity and mortality arising from these injuries. Conclusion: Neurovascular complications such as carotid artery and optic nerve injuries owing to disorientation in transsphenoidal surgery will reduce the use of neuronavigation with vascular micro-doppler.

Endoscopic pituitary surgery: Techniques, tips and tricks, nuances, and complication avoidance.

Endoscopic pituitary surgery is useful in all micro- and macro-pituitary adenomas including those with suprasellar and cavernous sinus extension. The endoscope provides a panoramic close-up, a multi-angled view with excellent illumination and magnification, permitting complete excision of the tumor with preservation of normal pituitary. However, surgeons need to learn altogether different skills unique to endoscopy and the learning curve is steep. The learning curve can be shortened by proper selection of cases, gradual transition from the microscopic to the endoscopic approach, adequate sphenoethmoidal recess widening, identification of important landmarks during each stage of surgery, and use of neuronavigation. Results and long term outcomes can be improved with bimanual dynamic dissection and sequential tumor excision, preservation of normal pituitary, avoidance of arachnoidal tear and use of extended approach for tumors with large suprasellar extension. The gradual transition from microscopic to endoscopic approach, adherence to step by step technique and learning 'tips and tricks' of the endoscopic pituitary surgery reduce complications.

Elucidating the utility of neuro-navigation in reducing malposition rates in Ommaya reservoir placement: 23-year operative experience at the Louisiana State University.

Variability exists with the use of neuro-navigation in the placement of Ommaya reservoir. In the setting of recent healthcare reforms in the United States that are focused on cost-containment strategies, we discuss from our experience at the Louisiana State University, Shreveport, if the use of high-cost stealth-guided navigation technique reduces malposition rates over free-hand placement. A retrospective cohort analyses on 146 patients that underwent placement of Ommaya reservoir between 1991 and 2014 using free-hand and neuro-navigated technique was performed. Primary endpoint was to evaluate the differences in rates of malposition across these two placement techniques. The mean age of our cohort was 44.85 ± 15.05 years and 45% patients were female. We did not find any statistical differences for complications rates including infections (8.3% vs 9.2%; P = 1.000), hemorrhage (0.0% vs 3.1%; P = 0.551), and repositioning (6.3% vs 8.2%; P = 1.000) across patients that underwent placement of Ommaya reservoir using neuro-navigation and free hand technique. Although placement of Ommaya reservoir is a relatively easier technique as compared to other neurosurgical procedures, based on our experience and literature, we found lower rates of complications in patients who underwent placement via the stealth-guided neuro-navigational approach. Despite not having found any statistical difference in malposition rates between navigated and free-hand implantation of Ommaya reservoirs in our series, it is plausible that the number of technical complications in the neuronavigational group in the early years of acquisition could possibly be attributed to the learning curve, rather than their occuring purely by chance. Nevertheless, considering the increased cost of hospitalization associated with the use of navigational technology, future studies are recommended to weigh the cost-benefit ratio of preferring the neuro-navigational techniques for placement of Ommaya reservoir over the free-hand placement techniques.