Brain surgery in a stereoscopic virtual reality environment: a single institution's experience with 100 cases

Neurosurgical Virtual Reality Simulation for Brain Tumor Using High-definition Computer Graphics: A Review of the Literature

Simulation and planning of surgery using a virtual reality model is becoming common with advances in computer technology. In this study, we conducted a literature search to find trends in virtual simulation of surgery for brain tumors. A MEDLINE search for “neurosurgery AND (simulation OR virtual reality)” retrieved a total of 1,298 articles published in the past 10 years. After eliminating studies designed solely for education and training purposes, 28 articles about the clinical application remained. The finding that the vast majority of the articles were about education and training rather than clinical applications suggests that several issues need be addressed for clinical application of surgical simulation. In addition, 10 of the 28 articles were from Japanese groups. In general, the 28 articles demonstrated clinical benefits of virtual surgical simulation. Simulation was particularly useful in better understanding complicated spatial relations of anatomical landmarks and in examining surgical approaches. In some studies, Virtual reality models were used on either surgical navigation system or augmented reality technology, which projects virtual reality images onto the operating field. Reported problems were difficulties in standardized, objective evaluation of surgical simulation systems; inability to respond to tissue deformation caused by surgical maneuvers; absence of the system functionality to reflect features of tissue (e.g., hardness and adhesion); and many problems with image processing. The amount of description about image processing tended to be insufficient, indicating that the level of evidence, risk of bias, precision, and reproducibility need to be addressed for further advances and ultimately for full clinical application.

Three-dimensional reconstruction and morphological characterization of pituitary macroadenomas

INTRODUCTION

The aim was to investigate the relationship between the tumor (clinicopathologic and radiological) characteristics and the morphological parameters of pituitary macroadenoma or giant adenoma patients using a three-dimensional (3D) reconstructed model.

MATERIAL AND METHODS

Magnetic resoanance imaging (MRI) was performed preoperatively; tumor grade was determined by the Knosp-Steiner classification and tumor morphology by the SIPAP classification. Pituitary adenomas and adjacent structures were reconstructed three-dimensionally by volume rendering.

RESULTS

Fifty-two and 6 patients underwent surgery via the transnasal transsphenoidal or pterional approach, respectively. Knosp-Steiner grades I to IV adenomas were observed in 5.2%, 25.9%, 22.4% and 46.6% of the patients, respectively. The 3D model was reconstructed in all cases with superb delineation of tumor morphology and the spatial relationship between the tumor and adjacent tissues. Pituitary adenomas were categorized into intrasellar (13.8%), suprasellar (20.7%), infrasellar (17.2%), and lobulated adenomas (48.3%). Suprasellar adenomas had the smallest (2.27 ±3.22 cm(3)) and lobulated adenomas the largest volume (24.61 ±30.50 cm(3)). Intrasellar adenomas were all functioning, while 75%, 60% and 60.7%, respectively, of suprasellar, infrasellar and lobulated adenomas were nonfunctioning, with a significant association between tumor morphology and secretory function (p = 0.005).

CONCLUSIONS

Three-dimensional reconstruction of pituitary macroadenomas offers a simplified morphological classification of pituitary adenomas and may be helpful for neurosurgeons to categorize and characterize pituitary adenomas.

The role of simulation in neurosurgery

PURPOSE

In an era of residency duty-hour restrictions, there has been a recent effort to implement simulation-based training methods in neurosurgery teaching institutions. Several surgical simulators have been developed, ranging from physical models to sophisticated virtual reality systems. To date, there is a paucity of information describing the clinical benefits of existing simulators and the assessment strategies to help implement them into neurosurgical curricula. Here, we present a systematic review of the current models of simulation and discuss the state-of-the-art and future directions for simulation in neurosurgery.

METHODS

Retrospective literature review.

RESULTS

Multiple simulators have been developed for neurosurgical training, including those for minimally invasive procedures, vascular, skull base, pediatric, tumor resection, functional neurosurgery, and spine surgery. The pros and cons of existing systems are reviewed.

CONCLUSION

Advances in imaging and computer technology have led to the development of different simulation models to complement traditional surgical training. Sophisticated virtual reality (VR) simulators with haptic feedback and impressive imaging technology have provided novel options for training in neurosurgery. Breakthrough training simulation using 3D printing technology holds promise for future simulation practice, proving high-fidelity patient-specific models to complement residency surgical learning.

3D preoperative planning in the ER with OsiriX®: when there is no time for neuronavigation

The evaluation of patients in the emergency room department (ER) through more accurate imaging methods such as computed tomography (CT) has revolutionized their assistance in the early 80s. However, despite technical improvements seen during the last decade, surgical planning in the ER has not followed the development of image acquisition methods. The authors present their experience with DICOM image processing as a navigation method in the ER. The authors present 18 patients treated in the Emergency Department of the Hospital das Clínicas of the University of Sao Paulo. All patients were submitted to volumetric CT. We present patients with epidural hematomas, acute/subacute subdural hematomas and contusional hematomas. Using a specific program to analyze images in DICOM format (OsiriX^®), the authors performed the appropriate surgical planning. The use of 3D surgical planning made it possible to perform procedures more accurately and less invasively, enabling better postoperative outcomes. All sorts of neurosurgical emergency pathologies can be treated appropriately with no waste of time. The three-dimensional processing of images in the preoperative evaluation is easy and possible even within the emergency care. It should be used as a tool to reduce the surgical trauma and it may dispense methods of navigation in many cases.

Operability of glioblastomas: "sins of action" versus "sins of non-action"

Despite prognosis of glioblastomas is still poor, mounting evidence suggests that more extensive surgical resections are associated with longer life expectancy. However, the surgical indications, at present, are far from uniform and the concept of operability is extremely surgeon-dependant. The results of glioblastoma resection in 104 patients operated on between March 2005 and April 2011 were reviewed with the aim to shed some light on the limits between 'sins of action' (operating upon complex tumors causing a permanent severe deficit) and 'sins of non-action' (considering inoperable tumors that can be resected with good results). Fifty-five patients (54.4 %) (Group 1) presented with a 'disputable' surgical indication because of one or more of the following clinico-radiological aspects: involvement of motor and language areas (39.4 %), deep location (7.7 %), corpus callosum infiltration (13.4 %), or major vessels encasement (8.6 %). Forty-six (42.5 %) patients (Group 2) presented with an 'indisputable' surgical indication (readily accessible tumors in non-eloquent areas). Overall mortality was 2.9 %. The mean overall survival was 19.8 months and not significantly different in the two Groups (20.4 Group 2 and 19.5 months for Group 1; p = 0.7). Patients with GTR and <72 years had a longer survival (p = 0.004 and 0.03, respectively). Seventy patients (69.3 %) showed an uneventful post-operative course, without statistical significance difference between Group 1 and 2. The gross total removal of glioblastoma with many complexities (Group 1) was found to be feasible with acceptable mortality, morbidity and long-term survival rates.

Stereoscopic virtual reality models for planning tumor resection in the sellar region

BACKGROUND

It is difficult for neurosurgeons to perceive the complex three-dimensional anatomical relationships in the sellar region.

METHODS

To investigate the value of using a virtual reality system for planning resection of sellar region tumors. The study included 60 patients with sellar tumors. All patients underwent computed tomography angiography, MRI-T1W1, and contrast enhanced MRI-T1W1 image sequence scanning. The CT and MRI scanning data were collected and then imported into a Dextroscope imaging workstation, a virtual reality system that allows structures to be viewed stereoscopically. During preoperative assessment, typical images for each patient were chosen and printed out for use by the surgeons as references during surgery.

RESULTS

All sellar tumor models clearly displayed bone, the internal carotid artery, circle of Willis and its branches, the optic nerve and chiasm, ventricular system, tumor, brain, soft tissue and adjacent structures. Depending on the location of the tumors, we simulated the transmononasal sphenoid sinus approach, transpterional approach, and other approaches. Eleven surgeons who used virtual reality models completed a survey questionnaire. Nine of the participants said that the virtual reality images were superior to other images but that other images needed to be used in combination with the virtual reality images.

CONCLUSIONS

The three-dimensional virtual reality models were helpful for individualized planning of surgery in the sellar region. Virtual reality appears to be promising as a valuable tool for sellar region surgery in the future.

Intraoperative image guidance in neurosurgery: development, current indications, and future trends

Introduction. As minimally invasive surgery becomes the standard of care in neurosurgery, it is imperative that surgeons become skilled in the use of image-guided techniques. The development of image-guided neurosurgery represents a substantial improvement in the microsurgical treatment of tumors, vascular malformations, and other intracranial lesions. Objective. There have been numerous advances in neurosurgery which have aided the neurosurgeon to achieve accurate removal of pathological tissue with minimal disruption of surrounding healthy neuronal matter including the development of microsurgical, endoscopic, and endovascular techniques. Neuronavigation systems and intraoperative imaging should improve success in cranial neurosurgery. Additional functional imaging modalities such as PET, SPECT, DTI (for fiber tracking), and fMRI can now be used in order to reduce neurological deficits resulting from surgery; however the positive long-term effect remains questionable for many indications. Method. PubMed database search using the search term "image guided neurosurgery." More than 1400 articles were published during the last 25 years. The abstracts were scanned for prospective comparative trials. Results and Conclusion. 14 comparative trials are published. To date significant data amount show advantages in intraoperative accuracy influencing the perioperative morbidity and long-term outcome only for cerebral glioma surgery.