A Comprehensive Three-Dimensional Simulation Method for Skull Base Meningioma Surgery.

Objective To study the image segmentation, three-dimensional (3D) reconstruction and simulation operation of choledocholithotomy and T-tube drainage based on the computed tomagraphy (CT) data of patient with choledocholithiasis. Methods Patient with choledocholithiasis underwent 64-slice spiral CT imaging. The images segmentation and 3D reconstruction were performed by Medical Image Process System (MIPS) to construct the 3D model of the hepatobiliary system. The model was modified by FreeForm Modeling System. The virtual surgical instruments were developed by GHOST SDK software, and were imported to the virtual surgery. Results The data of plain, arterial phase, venous phase and portal venous phase scanning were collected, and the data stored in DICOM format were transformed to BMP format. A model of the hepatobiliary system was constructed after the data was segmented by MIPS, and then the model was exported in the STL format. The data in STL format were imported to FreeForm Modeling System for smoothing the model. Different structures were assigned different colors to make the model more vivid. The self-developed virtual surgical instruments were imported to the system, and the virtual surgery for choledocholithiasis was performed with PHANToM. Conclusions With the help of MIPS, the image segmentation and 3D reconstruction of the model are finished rapidly and effectively. After the virtual surgical instruments are developed in FreeForm Modeling System, the virtual surgery can be achieved in the 3D model with the assistance of PHANToM. Key words: Choledocholithiasis; Three-dimensional reconstruction; Virtual surgery

The traditional treatment for brain cancer includes surgery, radiotherapy and chemotherapy. The neurosurgeon usually plans and performs the surgery with the help of two dimensional MRI images. If the size and the exact location of tumour is not clear it is difficult to perform a safe surgery and sometimes may cause permanent damage to the normal tissues. Such problems could be minimized by having first hand information regarding the tumour and hence an attempt is made in the present research to create 3D printed models of brain tumours using a medical image processing software based on MRI datasets. The MRI data saved as DICOM (Digital Imaging and Communications in Medicine) would be integrated with 3D slicer. 3D printer produces a physical 3D models using STL file generated from 3D slicer. Thus the 3D printed model of Brain Tumour could be served as a tool for preoperative surgical planning.

Radiation dose monitoring in medical imaging examination areas is mandatory for the reduction of patient radiation exposure. Recently, dose monitoring techniques that use digital imaging and communications in medicine (DICOM) dose structured reports (SR) have been introduced. The present paper discusses the setup of a radiation dose monitoring system based on DICOM data from university hospitals in Korea. This system utilizes the radiation dose data-archiving method of standard DICOM dose SR combined with a DICOM modality performed procedure step (MPPS). The analysis of dose data based on a method utilizing DICOM tag information is proposed herein. This method supports the display of dose data from non-dosimeter-attached X-ray equipment. This system tracks data from 62 pieces of equipment to analyze digital radiographic, mammographic, mobile radiographic, CT, PET-CT, angiographic, and fluorographic modalities.

BACKGROUND AND OBJECTIVES:The widespread use of endoscope and increased surgical experiences in pituitary adenomas (PAs) has raised the expectations for higher resection and cure rates. The subject that will meet this expectation in all types of adenomas is the capsule and its dissection. The purpose of this study was to go beyond the commonly mentioned pseudocapsule definition for small-sized adenomas in previous studies and to describe the capsule structure in different morphologies present in pituitary adenomas of all sizes. This includes detailing the nuances of capsular dissection (CD) and presenting postoperative surgical outcomes through the experiences of a high-volume tertiary center.METHODS:In our center, 534 patients underwent endoscopic trans-sphenoidal surgery because of pituitary adenoma in 2022 by the same surgeon. The data of the patients were examined retrospectively. The surgical techniques applied were grouped as adenoma resection only, capsular resection after internal debulking, and direct extracapsular resection.RESULTS:CD was performed in 275 (51.5%) patients. The gross total resection (GTR) rate in nonsecretory adenomas with and without CD was 90.7% (97/107) and 90.7% (97/107), respectively. The remission rate in secretory adenomas with and without CD was 81.0% (136/168) and 44.0% (67/152), respectively. When the patients were examined in 2 groups as those who underwent CD and those who did not, the application of CD had a positive predictive value in terms of GTR/remission (P: .036). Capsule thickness was not found to be statistically significant depending on tumor subtype, size, and aggressiveness, but capsule thickness was statistically significant in terms of total capsular resection (P: .045).CONCLUSION:The morphology of the capsule, tumor size/subtype/consistency, and patient-specific factors are crucial for the selection of the surgical technique to be applied. It is possible to increase the GTR/remission rates in adenomas of all sizes by capsule dissection. Moreover, performing CD does not contribute significantly to the development of potential complications in such cases.

Spinal clear cell meningioma without dural attachment: a case report and literature review

The Transorbital Approach to the Internal Carotid and Middle Cerebral Arteries. A Dissection Study towards Targeted Access Aneurysm Clipping

Background and Objective: In the last decade, the field of medicine has ingressed into a new era of technological advancements, driven by an ever increasing demand to reduce patient costs and risks, improve patient safety, efficiency, and surgical outcomes. The need for alternative ways of training and surgery is stronger than ever. Virtual reality based training and surgery systems hold significant promise in this direction. However, development of realistic virtual surgery systems for invasive orthopaedic surgical procedures remains one of the most challenging problems in the field of virtual reality based surgery and training because of the involvement of complex musculoskeletal structures and surgical tools. In recent years, some advances have been made in this area but they have limited practical scope because of their support for small range of procedures and training scenarios. The tools developed so far are either restricted in their ability or follow non patient-centric approaches and hence, cannot be considered viable alternatives to the conventional techniques for invasive orthopaedic surgery and training. In this paper, we discuss the challenges and complexities associated with the development of a virtual reality based system for orthopaedic training and surgery, and present our image guidance based navigation system, developed as part of our ongoing research initiative to build a comprehensive tool for realistic virtual orthopedic surgery and training.Methods: Our image guidance based interactive navigation system provides a common interface for the assembly of different components crucial for a realistic virtual reality based training and surgery application. Presently, the system incorporates various features including rigid body registration, patient-specific three-dimensional model generation, two-dimensional and three-dimensional interactive visualizations, and real time intraoperative surgical guidance. In this paper, we outline the details of our present system along with its key features.Results: A preliminary version of our proposed virtual reality based orthopaedic training and surgery navigation system is presented. To demonstrate the applicability of our system, a sample application showing the anatomically detailed three -dimensional representations of a patient's knee, derived from the pre-operative image scans, along with the corresponding two-dimensional image details is presented. To the best of our knowledge, this is the first attempt that constructs and integrates patient-specific, anatomically correct, and comprehensive three-dimensional models, with all possible soft tissue details, to provide patient-specific visualization and training capabilities. Preliminary feedback by the orthopaedic surgeons on the prototype of our system is very encouraging and pin points some additional features that can further strengthen the efficacy of our tool and its clinical adoption.Conclusion: A comprehensive virtual reality based navigation system for orthopaedic training and surgery is presented. The system utilizes patient-specific two-dimensional image modalities and provides corresponding two-dimensional and three-dimensional, interactive visualization capabilities along with realtime tracking of surgical instruments. The present system can be used as an effective tool for anatomy education, surgical planning, diagnosis, and real-time intra-operative surgical navigation. Additional components such as haptics and real-time tissue deformations are currently under development and will soon be integrated with this platform.

Expanded Endoscopic Transclival Approach for Resection of a Chordoid Meningioma without Dural Attachment (MWODA) Located in the Prepontine Cistern

BackgroundTechnological advances have dramatically changed medical education, particularly in the era of work-hour restrictions, which increasingly highlights a need for novel methods to teach surgical skills. The purpose of this study was to evaluate the validity of a novel, computer-based, interactive, cognitive simulator for training surgeons to perform pelvic lymph node dissection (PLND).MethodsEight prostate cancer experts evaluated the content of the simulator. Contextual aspects of the simulator were rated on a five-point Likert scale. The experts and nine first-year residents completed a simulated PLND. Time and deviations were logged, and the results were compared between experts and novices using the Mann–Whitney test.ResultsBefore training, 88% of the experts felt that a validated simulator would be useful for PLND training. After testing, 100% of the experts felt that it would be more useful than standard video training. Eighty-eight percent stated that they would like to see the simulator in the curriculum of residency programs and 56% thought it would be useful for accreditation purposes. The experts felt that the simulator aided in overall understanding, training indications, concepts and steps of the procedure, training how to use an assistant, and enhanced the knowledge of anatomy. Median performance times taken by experts and interns to complete a PLND procedure on the simulator were 12.62 and 23.97 minutes, respectively. Median deviation from the incorporated procedure pathway for experts was 24.5 and was 89 for novices.ConclusionWe describe an interactive, computer-based simulator designed to assist in mastery of the cognitive steps of an open surgical procedure. This platform is intuitive and flexible, and could be applied to any stepwise medical procedure. Overall, experts outperformed novices in their performance on the trainer. Experts agreed that the content was acceptable, accurate, and representative.

To study the surgery plan and simulation effect of the three dimensional (3D) hepatic virtual operation based on the data of 64-slice helical CT scanning and to probe the feasibility of the virtual operation based on the FreeForm Modeling System. The volunteer liver was scanned to collect two dimensional (2D) DICOM data of 64-slice helical CT scanning and the 3D hepatic and intrahepatic vessels model were reconstructed by MIMICS software. The reconstructed liver, the intrahepatic vessels model and the artificial tumor models were output into the FreeForm Modeling System in the STL format. The device PHANTOM with the characterization of dynamo-feedback was applied to make the operation on the 3D hepatic. The spatial relationship between the tumour and the intrahepatic vessels were clearly observed by rotation and enlargement of the target. According to the operation principle, the left lobe of liver resection was simulated by manipulating the device PHANToM. Through the liver transparence surface, the intrahepatic vessels were easily distinguished. The operation procedure was accord with the clinic hepatic surgery. Meanwhile, during the operation, by adjusting the incision objective intensity, the dynamo-feedback intensity was definitely touched. By using the FreeForm Modeling System,the hepatic operation procedure can be simulated ahead of time. The operation complication in the practical surgery can be anticipated and the individualization operation schema can be reasonable instituted.

Background: Foramen magnum meningiomas (FMMs) are rare skull base tumors whose surgical management is challenging due to their relationship with the brainstem, lower cranial nerves, and vertebral arteries. Methods: We retrospectively analyzed 14 patients who underwent microsurgical resection of FMMs between 2014 and 2024. Data included demographics, tumor location, surgical approach, extent of resection, complications, and functional outcomes. Results: The mean age was 51 years (range 29-82), with a female predominance (9/14). Tumors were anterior (15%), anterolateral (35%), lateral (35%), and posterior (15%). All patients were operated in the prone position, with a posterolateral suboccipital approach in four cases (28.5%). Gross total resection (Simpson III) was achieved in 85%. Complications included transient cranial nerve deficits (14%) and cerebrospinal fluid fistula (14%). No permanent deficits occurred. One patient (7.1%) died of postoperative complications. Mean Karnofsky Performance Score improved from 75 preoperatively to 90 at last follow-up. Conclusion: Tailored microsurgical approaches, guided by dural attachment and neurovascular configuration, enable safe and effective resection of FMMs with high rates of tumor control and favorable functional outcomes.

BackgroundMeningiomas are rather uncommon tumors in the pediatric population, differing significantly from those found in adults by their atypical location, higher rate of more malignant types, consequently higher risk of recurrence and a less favorable outcome. Even in children, suprasellar meningiomas without dural matrix are rare findings mimicking more common suprasellar lesions.Case presentationHere we describe a case of a 12-year-old girl who presented with a rapidly progressing chiasmal syndrome and was diagnosed by MRI with an unusual suprasellar tumor that could not fit the diagnoses expected in a case of a parasellar mass in a child, similar to a craniopharyngioma or optic pathway glioma. After multiple clinical investigations, the tumor etiology was still unclear, so the preferred option of treatment was surgical resection. An endoscope-assisted gross total resection through a supraorbital keyhole approach was performed uneventfully, with total vision recovery in a short time. Benign meningiomas located in the skull base without dural attachment appear to be rare, even in pediatric patients.ConclusionDifferential diagnoses of suprasellar and para sellar tumor lesions in pediatric patients can be confusing. There are peculiar features of pediatric tumor diseases that should be considered while working out the management strategy. The main principle of meningioma treatment is the highest possible extent of resection minimally affecting the quality of life.

Meningiomas present as intracranial extra-axial lesions with dural attachment, which are primarily managed surgically. The extent of resection (EOR) may vary depending on patient- and tumor-related factors. The aim of this study is to identify preoperative predictive factors of EOR and to propose an estimation of the predicted gross total resection (GTR) based of patient- and tumor-characteristics. 1469 patients from a retrospectively (1990 to 2002) and prospectively managed (2003 to 2010) databank of Oslo University Hospital, Norway, totalling 11,414 patient-years of follow-up were included. Patients had a mean age at surgery of 64 ± 20.1 years with a female-to-male ratio was 2.4:1 and a mean KPS of 81.2 ± 12.1. Skull-base meningiomas represented 47% of all cases. WHO grades were I in 92.3%, II in 5.2%, and III in 2.2%. Bone infiltration was described in 18.7% of cases. 39.3% of patients had Simpson I resection, 34.3% had Simpson II, 5.4% had Simpson III, 20.6% had Simpson IV, and 0.5% had Simpson V. The risk factors for incomplete resection were: symptomatic presentation (OR 0.56 [0.43–0.72]), skull-base location (OR 0.79 [0.70–0.88]), and bone invasion (OR 0.85 [0.73–0.99]). Using a recursive partitioning analysis, we propose a classification-tree for the prediction of GTR rate based on preoperatively determinable patient- and tumor characteristics. The identification of preoperative predictors of poor GTR rate may aid clinicians managing meningioma patients. In selected cases were the predicted GTR rate is low, staged treatment with surgical debulking followed by adjuvant therapy may be favored in order to minimize postoperative morbidity and mortality.

We describe a framework for training-oriented simulation of temporal bone surgery. Bone dissection is simulated visually and haptically, using a hybrid data representation that allows smooth surfaces to be maintained for graphic rendering while volumetric data is used for haptic feedback. Novel sources of feedback are incorporated into the simulation platform, including synthetic drill sounds based on experimental data and simulated monitoring of virtual nerve bundles. Realistic behavior is modeled for a variety of surgical drill burrs, rendering the environment suitable for training low-level drilling skills. The system allows two users to independently observe and manipulate a common model, and allows one user to experience the forces generated by the other’s contact with the bone surface. This permits an instructor to remotely observe a trainee and provide real-time feedback and demonstration.KeywordsHaptic FeedbackVolumetric DataHaptic RenderingDiamond BurrBone RemovalThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Virtual reality (VR) applications promise the safe, efficacious, and valid replication of scenarios encountered in modern neurosurgery, and a number of navigation- or dissection-related and endovascular simulators have been successfully deployed in the last 2 decades. Concurrently, neurosurgical training is changing, and VR simulations are expected to play a part in future training. To give an overview of currently available neurosurgical VR applications in the spectrum of desired applications and the outlook of the requirements to be met by future applications. The available literature was analyzed using structured Medline and PubMed searches. Relevant articles were retrieved and reviewed. When quantitative results were available, effect sizes were collated or estimated to check for publication bias. There has been a significant increase in publications concerning the use of VR in neurosurgery in the last 22 years (P < .001). Thirty-eight of 117 publications (32%) identified reported data regarding the use of a simulator by practitioners; 35 of these were reported as positive trials (92%). Twenty-two of 38 studies (58%) reported quantitative data with mostly small positive effect sizes (median, 1.41; interquartile range, 1.08-2). The use of VR simulators in endovascular surgery has the most robust basis, with 65% of studies reporting quantitative outcomes. Current neurosurgical VR applications focus on basic procedural skill acquisition and are valid and efficacious adjuncts to neurosurgical training. In the future, the development of complex procedural simulators, teamwork, and focus on validated measures will lead to robust framework of the use of VR over the entire career of a neurosurgeon.