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PubMed2005

Neuronavigation in skull base tumors.

OBJECTIVE: Computer-assisted neuronavigation was used in 87 cases of skull base lesions (SBLs). Preoperative planning and intraoperative identification of anatomic landmarks is especially important in SBLs since it helps to avoid or minimize surgical morbidity and mortality. In this study, we assessed the accuracy and the clinical usefulness of a frameless system based on the optical digitizer in SBLs. PATIENTS AND METHODS: Between April 2000 and March 2003, eighty-seven patients with SBLs were operated on in our department using cranial neuronavigation. A passive-marker-based neuronavigation system was used for intraoperative image guidance. There were 56 women and 31 men. The patient's ages ranged from 4 to 76 years (average: 45.7 year). The locations of the tumors reported in this series were as follows: frontobasal, 24 cases; sellar/parasellar, 32 cases; petroclival, 16 cases; tentorial/subtemporal, 15 cases. RESULTS: The computer-calculated registration accuracy ranged between 0.3 and 1.7 mm (mean, 1.1 mm). Gross total removal of the SBLs was accomplished in 82 out of 87 patients as was confirmed on postoperative CT and MRI scans. The follow-up period ranged from 1 month to 48 months (average: 20.1 months). Overall mortality and severe morbidity (meningitis, permanent cranial nerve deficits, and cerebrospinal fluid fistulae) rates were 4.6 % and 33.3 %, respectively. CONCLUSION: The image-guided surgery is a valuable aid for safe, helpful and complete removal of SBLs of the brain where accurate localization of the lesion is critical. Although our preliminary series is not large, interactive image guidance provides a constant display of surgical instrument position during surgery and its relationship with the SBLs components, surrounding normal brain, and vascular structures, providing valuable guidance to the surgeon during an operation. Our experience with the neuronavigation suggests that image guidance is helpful in this type of lesions, providing better anatomic orientation during skull base surgery, delineating tumor margins and their relation to critical neurovascular structures.

Adolescent↗
PubMed2006

Application of neuronavigation system to brain tumor surgery with clinical experience of 420 cases.

A new era of neurosurgery has recently been unveiled with the advent of image-guided surgery. The use of neuronavigation is beginning to have a significant impact on a variety of intracranial procedures. Herein, we report our clinical experience using a neuronavigation system with different surgical applications and techniques for a variety of brain tumors. We used the BrainLab VectorVision neuronavigation system, which is a frameless and image-guided system. We operated on 420 cases having various types of brain tumor with the help of this system. The mean target localizing accuracy and mean volume were 1.15 mm and 30.8 mL (0.2-216.4 mL), respectively. We utilized this system to effectively make bone flaps, to detect critically located, deep-seated, subcortical, skull-base and skull bone tumors, and to operate on intraparenchymal lesions with grossly unclear margins, such as gliomas. We also performed tumor biopsy using the combination of a conventional stereotactic biopsy instrument and an endoscope. The application of the neuronavigation system not only revealed benefits for operative planning, appreciation of anatomy, lesion location and the safety of surgery, but also greatly enhanced surgical confidence.

Adolescent↗
PubMed2006

intraoperative neuronavigation using diffusion tensor MR tractography for the resection of a deep tumor adjacent to the corticospinal tract.

OBJECTIVE AND IMPORTANCE: Delineation of cerebral white matter tracts using MR tractography adds essential information for planning intracranial surgery. Integrating tractography with intraoperative neuronavigation may reduce the likelihood of new neurological deficits after surgery done to remove tumors adjacent to the projection fibers of eloquent cortex. We report the utility of such integration for the resection of deep (paraventricular) tumors. CLINICAL PRESENTATION: A 67-year-old male with malignant melanoma underwent stereotactic radiosurgery for a single metastasis within the paraventricular white matter of the right frontal lobe near the corticospinal tract. The lesion doubled in size within 12 months of radiotherapy. Surgical extirpation was performed aided by intraoperative neuronavigation. TECHNIQUE: MR images of the brain including MR tractography and post-contrast T1-weighted sequences were acquired and imported into a neuronavigational workstation. Asymmetric fusion of contrast-enhanced images and tractography was employed to assist in preservation of the integrity of critical white matter tracts during the surgical procedure. CONCLUSION: Inclusion of tractography in standard imaging protocols for neuronavigational systems may increase the safety of neurosurgical intervention near white matter tracts, including deep areas adjacent to the ventricles.

Aged↗
PubMed2004

Neuronavigation-assisted cranial reconstruction.

OBJECTIVE: Cranial defects resulting from congenital deformities, ablative resection of osseous tumors, traumatic injury, and destructive infectious lesions are often severe enough to warrant surgical reconstruction. In particular cases, satisfactory cosmetic results may be difficult to achieve because of the extent and location of the lesion. METHODS: We evaluated the role of neuronavigation for reconstruction of large cranial defects with prefabricated titanium and intraoperatively constructed neuronavigation-assisted polymethylmethacrylate implants. RESULTS: Neuronavigation-assisted cranial reconstruction was performed in 14 patients. Surgical procedure, illustrative cases, postoperative results, and apparent benefits of the technique are presented and discussed. In all patients, excellent cosmetic results were achieved. CONCLUSION: In cranial reconstruction, neuronavigation is of value not only for intraoperative determination of resection margins but also for preoperative assessment and planning. The combination of navigation techniques with prefabricated or intraoperatively constructed implants enables achievement of excellent cosmetic results.

Adult↗
PubMed2004

Functional magnetic resonance imaging-integrated neuronavigation: correlation between lesion-to-motor cortex distance and outcome.

OBJECTIVE: The integration of functional magnetic resonance imaging (fMRI) data into neuronavigation is a new concept for surgery adjacent to the motor cortex. However, the clinical value remains to be defined. In this study, we investigated the correlation between the lesion-to-fMRI activation distance and the occurrence of a new postoperative deficit. METHODS: fMRI-integrated "functional" neuronavigation was used for surgery around the motor strip in 54 patients. During standardized paradigms for hand, foot, and tongue movements, echo-planar imaging T2* blood oxygen level-dependent sequences were acquired and processed with BrainVoyager 2000 software (Brain Innovation, Maastricht, The Netherlands). Neuronavigation was performed with the VectorVision(2) system (BrainLAB, Heimstetten, Germany). For outcome analysis, patient age, histological findings, size of lesion, distance to the fMRI areas, preoperative and postoperative Karnofsky index, postoperative motor deficit, and type of resection were analyzed. RESULTS: In 45 patients, a gross total resection (>95%) was performed, and for 9 lesions (low-grade glioma, 4; glioblastoma, 5), a subtotal resection (80-95%) was achieved. The neurological outcome improved in 16 patients (29.6%), was unchanged in 29 patients (53.7%), and deteriorated in 9 patients (16.7%). Significant predictors of a new neurological deficit were a lesion-to-activation distance of less than 5 mm (P < 0.01) and incomplete resection (P < 0.05). CONCLUSION: fMRI-integrated neuronavigation is a useful concept to assess the risk of a new motor deficit after surgery. Our data suggest that a lesion-to-activation distance of less than 5 mm is associated with a higher risk of neurological deterioration. Within a 10-mm range, cortical stimulation should be performed. For a lesion-to-activation distance of more than 10 mm, a complete resection can be achieved safely. The visualization of fiber tracks is desirable to complete the representation of the motor system.

Adult↗
PubMed2005

High-resolution three-dimensional T2-weighted sequence for neuronavigation: a new setup and clinical trial.

OBJECT: Conventional imaging for neuronavigation is performed using high-resolution computerized tomography (CT) scanning or a T1-weighted isovoxel magnetic resonance (MR) sequence. The extension of some lesions, however, is depicted much better on T2-weighted MR images. A possible fusion process used to match low-resolution T2-weighted MR image set with a referenced CT or T1-weighted data set leads to poor resolution in the three-dimensional (3D) reconstruction and decreases accuracy, which is unacceptable for neuronavigation. The object of this work was to develop a 3D T2-weighted isovoxel sequence (3D turbo-spin echo [TSE]) for image-guided neuronavigation of the whole brain and to evaluate its clinical application. METHODS: The authors performed a phantom study and a clinical trial on a newly developed T2-weighted isovoxel sequence, 3D TSE, for image-guided neuronavigation using a common 1.5-tesla MR imager (Siemens Sonata whole-body imager). The accuracy study and intraoperative image guidance were performed with the aid of the pointer-based Medtronic Stealth Station Treon. The 3D TSE data set was easily applied to the navigational setup and demonstrated a high registration accuracy during the experimental trial and during an initial prospective clinical trial in 25 patients. The sequence displayed common disposable skin fiducial markers and provided convincing delineation of lesions that appear hyperintense on T2-weighted images such as low-grade gliomas and cavernomas in its clinical application. CONCLUSIONS: Three-dimensional TSE imaging broadens the spectrum of navigational and intraoperative data sets, especially for lesions that appear hyperintense on T2-weighted images. The accuracy of its registration is very reliable and it enables high-resolution reconstruction in any orientation, maintaining the advantages of image-guided surgery.

Adult↗
PubMed1999

[Neuronavigation for the resection of intracranial cavernous angiomas].

OBJECTIVE: To evaluate the use of the Stealth Station neuronavigator in conjunction with preoperative computerized tomography (CT) in the resection of intracranial cavernous angiomas (CAs). METHODS: The Stealth Station neuronavigator was used to provide real-time correlation of the operating field and computerized images in 6 patients with CAs. All of them suffered from epileptic seizures. RESULTS: Neuronavigation-guided lesionectomy with removal of hemosiderin deposition, gliosis and calcification in all cases was performed precisely. Mean fiducial error, predicted accuracy at 10 cm, and sustained accuracy ranged from 1.65 to 4.53 mm, 1.82 to 3.28 mm, and 0.50 to 3.45 mm, respectively. CONCLUSIONS: The Stealth Station neuronavigator is reliable and accurate in the resection of CAs.

Adolescent↗
PubMed2003

Neuronavigator-guided glioma surgery.

OBJECTIVE: To evaluate the effectiveness of neuronavigator-guided surgery for the resection of gliomas. METHODS: A total of 80 patients with gliomas underwent surgical treatment under the StealthStation neuronavigator to estimate the extent of the tumors. In 27 cases, the measurements of brain shifts at the dura, cortical surface and lesion margin were recorded during the operations. A technique termed "micro-catheter fence post" was used in superficial gliomas to compensate for brain shift. RESULTS: Mean fiducial error and predicted accuracy in the 80 cases were 2.03 mm +/- 0.89 mm and 2.43 mm +/- 0.99 mm, respectively. The shifts at the dura, cortical surface and lesion margin were 3.44 mm +/- 2.39 mm, 7.58 mm +/- 3.75 mm, and 6.55 mm +/- 3.19 mm, respectively. Although neuronavigation revealed residual tumors, operations were discontinued in 5 cases of deep-seated gliomas. In the other 75 cases, total tumor removals were achieved in 62 (82.7%), and subtotal removals were achieved in 13 (17.3%). Post-operation, neurological symptoms were improved or unchanged in 68 cases (85.0%), and worsened in 12 (15.0%). No deaths occurred during the operations and post-operations. CONCLUSIONS: Intraoperative brain shifts mainly contribute to the fail of spatial accuracy during neuronavigator-guided glioma surgery. The "micro-catheter fence post" technique used for glioma surgery is shown to be useful for compensating for intraoperative brain shifts. This technique, thus, contributes to an increase in total tumor removal and a decrease in surgical complications.

Adolescent↗
PubMed2004

[Neuronavigation-assisted microanatomical study of the facial nerve canal through the transpetrosal approach].

OBJECTIVE: To study the value of neuronavigation in the transpetroal approach, and to provide anatomic data for the protection of the nerves in the facial nerve canal (FNC) during surgeries. METHODS: Simulated surgery through the transpetroal approach was performed on 16 sides of 8 adult cadaver heads with the assistance by neuronavigation. The anatomy of the facial nerve and the relationship of related structures were observed and the distances from the utmost external edge of the mastoid to different segments of the FNC were measured. RESULTS: Neuronavigation was successful with all the FNC, with the mean error of less than 0.9 mm. The FNC could be divided into 3 segments, the labyrinthine, the tympanic and the mastoid segments, stretching 3.6+/-1.2 mm, 11.2+/-2.5 mm and 16.1+/-3.6 mm respectively and with diameters of 1.2+/-0.3 mm, 1.4+/-0.1 mm and 1.7+/-0.2 mm, respectively. CONCLUSION: Neuronavigation may help protect the FNC during surgical procedures, and a thorough knowledge of the anatomic features of the FNC can be significant for preservation of the facial nerves.

Adult↗
PubMed2005

[Neuronavigation and electrocorticography monitoring in resection of brain cavernous malformations].

OBJECTIVE: To investigate the indications, technical considerations, and effects of neuronavigation and electrocorticography (ECOG) monitoring in resection of brain cavernous malformations (CM). METHODS: From 1997 to 2003, 70 patients with CM, 53 males and 17 females, aged 33 (8 - 62), underwent resection of CM using neuronavigation and neurophysiological monitoring. The first episodes included hemorrhage (31 cases, 44.3%), seizure (29 cases, 41.4%), headache (5 cases, 7.1%), and focal neurological deficit (4 cases, 5.7%). One case was asymptomatic (1.4%), only discovered during physical examination. The size of CM focus was 21 mm (5-50 mm). The depth of tumor measured from the surface was 3-70 mm. Six patients had multiple lesions. The foci were located deep in the white matter of hemispheres in 39 cases, within the brainstem in 9 cases, within the basal ganglia or thalamus in 11 cases, within the cerebellum in 5 cases, and within the optic nerve in 1 case. Preoperatively a MRI procedure using 5 skin markers was performed with the data transferred to a neuronavigation workstation, thus reconstructing a three-dimensional image of the tumor. Supratentorial subcortical lobar cavernomas underwent microsurgery through sulcus and fissure approach. ECOG monitoring was performed on 29 patients with seizure during the operation and bipolar electrocoagulation on functional cortex was conducted. Follow-up was conducted for 19.4 months (6-24 months). RESULTS: No intraoperative death was found. Postoperative disability rate was 8.6%. Complete removal of the lesion demonstrated by postoperative MRI was obtained in all patients. New transitory neurological deficits occurred in 4 patients after operation and recovered within 1 month. Hemiparesis developed in 1 patient with thalamus CM (1.4%) and facial paralysis developed in 1 patient with pons CM, and both recovered in 6 mouths. Nineteen out of the 24 patients with preoperative seizure history (79.2%) were postoperatively free of seizure, five (20.8%) of them showed improvement. CONCLUSION: Patients with asymptomatic CM can be kept under observation. CM deep in brain after the first bleeding is the indication of surgical treatment. Combination of neuronavigation and neurophysiological monitoring contributes to safety of operation and decrease of postoperative disability rate.

Adolescent↗
PubMed2005

Supratentorial cavernomas in eloquent brain areas: application of neuronavigation and functional MRI in operative planning.

AIM: Cavernomas located in eloquent areas of cerebral hemispheres represent a challenge for the neurosurgeon. An accurate surgical approach is essential to completely remove the lesion with function preservation. Aim of this study was to evaluate the usefulness of integration between standard magnetic resonance imaging (MRI) for neuronavigation and functional MRI (fMRI) in preoperative planning and intraoperative removal of cavernomas. METHODS: Between June 2000 and December 2002, 21 patients underwent surgery for supratentorial subcortical cavernomas. Eleven lesions were located adjacent to eloquent brain areas. All the patients in the series underwent MRI for neuronavigation and, since January 2002, in 6 cases of lesions located in eloquent areas, fMRI was also performed, with subsequent images fusion. The surgical approach was performed via the transgyral route under conventional and ultrasound-guided neuronavigation. RESULTS: All the lesions were totally removed. No morbidity was seen in patients harbouring lesions in non eloquent areas. Four patients with lesions in critical areas suffered transient focal deficits, but only one patient of this series was operated on by the auxilium of image fusion. In 7 patients operated on by conventional image-guided surgery and affected by preoperative seizures, no further seizures were observed after surgery. In 3 patients more hosting lesions neighbouring critical areas, the perilesional ring was not removed, observing persistence of seizures pharmacologically treated. In 4 of the 6 patients (all affected by seizures), operated on by fMRI auxilium, lesion removal was associated to the removal of the perilesional ring. No further epilepsy was seen in these patients. CONCLUSIONS: In all the cases the use of neuronavigation allowed minimally invasive approaches and radical excision of the lesions. Moreover, fMRI seemed to provide important additional information in patients with lesions in eloquent brain areas, allowing a more aggressive approach on the perilesional tissue to the aim of resolving seizures, in absence of an increase in the morbidity rate.

Adolescent↗
PubMed1998

Intraoperative localization of functional regions in the sensorimotor cortex by neuronavigation and cortical mapping.

Surgery of lesions within the central region requires exact intraoperative anatomical orientation and knowledge of the position of functional cortical regions to minimize the surgical trauma and to avoid postoperative neurological deficits. We combined somatosensory evoked potential (SSEP) phase reversal and/or cortical electrical stimulation with neuronavigation in 26 patients for localization and visualization of functional cortical areas and their anatomical site in relation to the lesion. After location of the central sulcus by means of SSEP phase reversal, the precentral gyrus was electrically stimulated to detect functional motor regions. Electrode position was documented, and the functional regions were related to the site of the lesion using a specially developed neuronavigation system. In 11 of 15 patients the central fissure was located with SSEP phase reversal. Electrical stimulation yielded motor evoked potentials in 23 of the total 26 patients. The anatomical site of these functional regions and their relation to the lesion were evaluated with the neuronavigation system. The precentral gyrus, central sulcus, and postcentral gyrus could be identified in all 23 cases. The combination of intraoperative electrophysiological mapping and neuronavigation provides safe and reliable localization of the sensorimotor cortex. This technique is a promising tool to minimize the risk of surgically caused sensory and motor deficits.

Adult↗
PubMed1999

Neuronavigation in intraoperative MRI.

OBJECTIVE: We describe the development and implementation of an image-guided surgical system combining the best features of conventional frameless stereotactic systems and the recently developed superconductive vertically configured intraoperative magnetic resonance scanner. The incorporation of intraoperatively updated magnetic resonance imaging (MRI) data sets into the neuronavigation computer overcomes one of the main disadvantages of these systems, i.e., intraoperative brain shift. METHODS: The integrated system consists of a 0.5-T MRI scanner (Signa SP General Electric Medical Systems, Milwaukee, WI), a neuronavigation computer with associated software (OTS Radionics, Burlington, MA), and an emulation program linking the two. The scanner has a 60-cm-wide vertical gap where both imaging and surgery are conducted, in-bore infrared linear cameras and monitors for interactive surgical neuronavigation, and flexible surface coils specially designed for surgery. RESULTS: Phantom studies showed navigational accuracy to be better than that obtained using conventional preoperative images and surface markers for patient registration. Our initial 17 cases using this integrated system comprised 16 craniotomies and one biopsy, and demonstrated decreased operative duration, greater frequency of interactive image guidance utilization, and better assessment of the progress of surgery compared to the cases previously done in the intraoperative MRI. CONCLUSION: This initial study of the addition of frameless stereotactic systems to the basic intraoperative MRI concept has demonstrated its clinical usefulness. The use of the intraoperative MRI greatly reduces the basic weakness of neuronavigation inaccuracy due to target shift. The surgical procedure performed in the imaging volume of the MRI scanner eliminates the problems of patient or scanner transport during the procedure. Immobilization of the patient throughout the procedure eliminated the need for reregistration of the patient, by taking advantage of the fixed camera system in the bore of the MRI system.

Adult↗
PubMed1993

Neuronavigator-guided cerebral biopsy.

Neuronavigators are new dynamic interactive instruments that use on-line computers to orient imaging data to the surgical field and guide the neurosurgeon to his target. We have been working since 1987 on a neuronavigator that serves not only as a precise pointer, but also as a dynamic arm that can be used to hold instruments, such as biopsy guides. The neuronavigator arm consists of six joints with optical encoders and is attached to the Mayfield headholder. The arm is connected to a workstation running customized 3D image graphics software. Special instruments and surgical technique have been developed. Here, we report on early clinical experience with ten biopsy procedures: 4 low-grade and 3 high-grade astrocytomas, one craniopharyngioma and one chronic intracerebral haematoma and intracerebral cyst, both of the latter with surrounding tumour suspect tissue. In all glioma cases serial biopsies were taken from optimal sites under ultrasound imaging control. Eight cases showed representative tumour tissue, while in two cases neoplasia was ruled out. The neuronavigator proved to be versatile, allowing comprehensive imaging data to be adapted to the surgical field.

Astrocytoma↗
PubMed1998

[Neuronavigation. Methods and prospects].

With the recent developments in computer technology and the improvements in modern neuroimaging, frame-based stereotactic guidance for open microsurgical procedures has been increasingly replaced by neuronavigation, also called frameless stereotaxy. It allows transfer of individual patientís images onto the operative field to assist the neurosurgeon intraoperatively in defining the tumor margins or identifying functionally important brain areas. The different localization techniques employed are articulated position-sensing arms, infrared or ultrasound systems working with the principle of satellite navigation and robotic systems integrated with the operating microscope. In 200 operations performed with different systems (arm-based, robotic and infrared) the method proved to be helpful, enabling fewer invasive procedures to be performed. With a mean deviation of 2.87 +/- 1.9 mm for intraoperative localization, the accuracy was only slightly worse than in frame-based stereotaxy with deviations below 2 mm. Neuronavigation was most helpful for operations on deeply seated lesions, skull-base tumors and lesions in brain areas with high functionality. The major disadvantage is the use of preoperative data for navigation, leading to inaccuracies when anatomical structures are altered during the operation by resection of tumors or shift of intracranial soft tissue. Intraoperative magnetic resonance imaging (MRI) might be a solution for this problem. With the method of intraoperative MRI developed in our department it has already been possible to update neuronavigation with images reflecting intraoperative changes in anatomy. Therefore, neuronavigation is definitely a method with growing importance in operative routine, and it will also spread into other surgical specialties.

Brain Diseases↗
PubMed2002

Ventricular catheter placement in children with hydrocephalus and small ventricles: the use of a frameless neuronavigation system.

OBJECT: Accurate placement of ventricular catheters in children with small ventricles can be difficult. Too often, shunt catheters are misplaced with regard to optimal position and trajectory. The objective of this study was to determine whether neuronavigation-guided free-hand placement of ventricular catheters is an effective adjunct for children with hydrocephalus and small ventricles. METHODS: Nine children with hydrocephalus (ages 1-12 years) participated in this study. Four children were diagnosed as suffering from slit ventricle syndrome and 5 children had small to mildly dilated ventricles. Of the 9 shunted children, 6 underwent previous shunt placements, and 1 child previously underwent an endoscopic third ventriculostomy. In 8 children the primary procedure was insertion of ventricular catheters using a frameless neuronavigation system. In 1 child, the neuronavigation system was used after failure to insert the ventricular catheter using a standard technique. All children showed significant improvement of their symptoms and signs following the procedure and none of them required shunt revision during the follow up period (mean 8+/-5 months). CONCLUSION: The usage of a neuronavigation system is safe and may be beneficial for optimal positioning and trajectory of ventricular catheters in children with small ventricles or an abnormal ventricular anatomy.

Cerebral Ventricles↗
PubMed2002

Practicability of magnetoencephalography-guided neuronavigation.

Magnetoencephalography (MEG) is a noninvasive option for localizing electroneurophysiological activity on the human cortex. The purpose of this study was to evaluate the practicability and reliability of MEG imaging integrated into a neuronavigation system to identify the sensorimotor cortex intraoperatively in patients with brain tumors in or near the central motor strip. It was performed prior to surgery in 30 patients with space-occupying lesions in or around the central region to localize the primary somatosensory cortex. These functional brain maps were superimposed on MR images obtained prior to surgery and transferred in the operating room for intraoperative functional neuronavigation. During surgery, the phase reversal technique identified a generator which coincided with the somatosensory cortex as displayed by the MEG-based functional neuronavigation system. Following surgery, the motor deficit improved in seven patients, was unchanged in five, and showed a slight transient deterioration in five. One patient suffered a deterioration of motor function with incomplete recovery. The MEG-based functional neuronavigation was found to be practicable and useful in finding a safe approach to tumors in or adjacent to the central region. The accuracy of MEG was concluded to be reliable as verified by the phase reversal technique.

Adult↗
PubMed2000

Cranial neuronavigation in neurosurgery: assessment of usefulness in relation to type and site of pathology in 284 patients.

OBJECTIVE: Neuronavigation improves intraoperative topographical orientation in neurosurgery. We wanted to better define the practical value of this technique in relation to the pathology operated on and the types of cranial surgery that profit the most from it. METHODS: Usefulness, interactive use and probably preventive effect of neuronavigation in cranial neurosurgery were assessed in a consecutive series of 284 patients on the basis of questionnaires with two- or five-point scale ratings by different neurosurgeons. RESULTS: Neuronavigation was most helpful in tumors of the hemispheres (particularly the central area) not visible at the cortical surface or resembling normal white matter, and in endoscopic procedures within small ventricles or cysts with non-translucent walls or when vision was blurred by cloudy CSF. In the same pathologies and surgical procedures, the device was interactively used, taking advantage of the specific possibilities of interactive image-guided neurosurgery. A probably preventive effect of neuronavigation was noted in operations in eloquent areas; highest scores were given for intraaxial tumors of the central region. The subjective assessments of usefulness, interactive use or preventive effect were not dependent on the involvement of the neurosurgeons in this study. CONCLUSION: We recommend this technique in resecting tumors in eloquent areas of the cortex or white matter, in approaching deep-seated processes not visible at the cortical surface, in defining borders of tumors resembling normal brain tissue, and in guiding endoscopes where ventricles are small or vision is blurred. This recommendation applies to any neurosurgeon familiar with the technique and managing neurosurgical cases requiring precise topographical orientation where normal anatomic landmarks are missing.

Adolescent↗