Quantitative assessment and objective improvement of the accuracy of neurosurgical planning through digital patient-specific 3D models.

Objective: Neurosurgical patient-specific 3D models have been shown to facilitate learning, enhance planning skills and improve surgical results. However, there is limited data on the objective validation of these models. Here, we aim to investigate their potential for improving the accuracy of surgical planning process of the neurosurgery residents and their usage as a surgical planning skill assessment tool. Methods: A patient-specific 3D digital model of parasagittal meningioma case was constructed. Participants were invited to plan the incision and craniotomy first after the conventional planning session with MRI, and then with 3D model. A feedback survey was performed at the end of the session. Quantitative metrics were used to assess the performance of the participants in a double-blind fashion. Results: A total of 38 neurosurgical residents and interns participated in this study. For estimated tumor projection on scalp, percent tumor coverage increased (66.4 ± 26.2%-77.2 ± 17.4%, p = 0.026), excess coverage decreased (2,232 ± 1,322 mm2-1,662 ± 956 mm2, p = 0.019); and craniotomy margin deviation from acceptable the standard was reduced (57.3 ± 24.0 mm-47.2 ± 19.8 mm, p = 0.024) after training with 3D model. For linear skin incision, deviation from tumor epicenter significantly reduced from 16.3 ± 9.6 mm-8.3 ± 7.9 mm after training with 3D model only in residents (p = 0.02). The participants scored realism, performance, usefulness, and practicality of the digital 3D models very highly. Conclusion: This study provides evidence that patient-specific digital 3D models can be used as educational materials to objectively improve the surgical planning accuracy of neurosurgical residents and to quantitatively assess their surgical planning skills through various surgical scenarios.

Use of a new low-profile coronary stent graft for the treatment of intracranial carotid blow-out.

A 50-year-old male patient with a history of transcranial surgery and subsequent radiotherapy for a pituitary adenoma presented with repetitive pulsatile nasal bleeding. A right cavernous segment pseudoaneurysm was discovered on the angiogram, and the patient failed the balloon occlusion test. A Papyrus (Biotronik, Berlin, Germany) stent graft, which is approved for coronary interventions, was successfully deployed over a coaxial guiding system during the emergent treatment of the false aneurysm. The patient tolerated the procedure well and nasal bleeding did not recur after the procedure. At one-year angiographic follow-up, the stent graft was patent and there was no evidence of recanalization of the false aneurysm.

Repeat endoscopic endonasal transsphenoidal surgery for residual or recurrent cushing's disease: safety, feasibility, and success.

PURPOSE: The success and outcomes of repeat endoscopic transsphenoidal surgery (ETS) for residual or recurrent Cushing's disease (CD) are underreported in the literature. This study aims to address this gap by assessing the safety, feasibility, and efficacy of repeat ETS in these patients. METHODS: A retrospective analysis was conducted on 56 patients who underwent a total of 65 repeat ETS performed by a single neurosurgeon between January 2006 and December 2020. Data including demographic, clinical, laboratory, radiological, and operative details were collected from electronic medical records. Logistic regression was utilized to identify potential predictors associated with sustained remission. RESULTS: Among the cases, 40 (61.5%) had previously undergone microscopic surgery, while 25 (38.5%) had prior endoscopic procedures. Remission was achieved in 47 (83.9%) patients after the first repeat ETS, with an additional 9 (16.1%) achieving remission after the second repeat procedure. During an average follow-up period of 97.25 months, the recurrence rate post repeat surgery was 6.38%. Sustained remission was achieved in 48 patients (85.7%), with 44 after the first repeat ETS and 4 following the second repeat ETS. Complications included transient diabetes insipidus (DI) in 5 (7.6%) patients, permanent (DI) in 2 (3%) patients, and one case (1.5%) of panhypopituitarism. Three patients (4.6%) experienced rhinorrhea necessitating reoperation. A serum cortisol level > 5 µg/dL on postoperative day 1 was associated with a reduced likelihood of sustained remission. CONCLUSION: Repeat ETS is a safe and effective treatment option for residual or recurrent CD with satisfactory remission rates and low rates of complications.

Creating a neuroanatomy education model with augmented reality and virtual reality simulations of white matter tracts.

OBJECTIVE: The utilization of digital technologies has experienced a notable surge, particularly in cases where access to cadavers is constrained, within the context of practical neuroanatomy training. This study evaluates augmented reality (AR)- and virtual reality (VR)-based educational models for neuroanatomy education. METHODS: Three-dimensional models were created using advanced photogrammetry. VR- and AR-based educational models were developed by arranging these 3D models to align with the learning objectives of neurosurgery residents and second-year medical students whose cadaveric training was disrupted due to an earthquake in Turkey. Participants engaged with and evaluated the VR- and AR-based educational models, followed by the completion of a 20-item graded user experience survey. A 10-question mini-test was given to assess the baseline knowledge level prior to training and to measure the achievement of learning objectives after training. RESULTS: Forty neurosurgery residents were trained with a VR-based educational model using VR headsets. An AR-based educational model was provided online to 200 second-year medical students for their practical neuroanatomy lesson. The average correct answer rates before the training were 7.5/10 for residents and 4.8/10 for students. These rates were significantly improved after the training to 9.7/10 for residents and to 8.7/10 for students (p < 0.001). Feedback from the users concurred that VR- and AR-based training could significantly enhance the learning experience in the field of neuroanatomy. CONCLUSIONS: VR/AR-based educational models have the potential to improve education. VR/AR-based training systems can serve as an auxiliary tool in neuroanatomy training, offering a realistic alternative to traditional learning tools.

Endonasal endoscopic approach for sellar metastatic pathologies: a national observation.

PURPOSE: Sellar metastases are rare lesions. Recent improvements in diagnosis and treatment strategies have prolonged survival but increased the probability of metastatic tumors. Evaluation with clinical symptomatology and meticulous laboratory examination is crucial. We present our multicenter national study on sellar metastases to evaluate and underline the main clinical, endocrine, and radiological considerations regarding the diagnosis and endonasal endoscopic management of such rare lesions. METHODS: A medical literature-based retrospective study was planned across 13 neurosurgical centers in Turkey, where a data survey was conducted to collect information regarding sellar metastases surgically treated using the endoscopic endonasal approach, including clinical presentation, radiographic features, primary tumor origin, histopathological confirmation, time to metastasis, treatment, and patient outcomes. RESULTS: Between 2010 and 2020, 54 patients (22 women [40.7%] and 32 men [59.3%]) who underwent surgery with the endonasal endoscopic approach and had pathologically proven sellar metastases (overall incidence, 0.54%) were included. Of the patients, 59.3% had no known malignancy and presented with new-onset symptoms, 79.6% reported headache, 51.9% complained of some degree of visual deficits, and 50% had cranial nerve symptoms. Tissue biopsy was performed in 7.4% of the patients, whereas gross or subtotal resection was achieved in the remaining patients. CONCLUSION: To our knowledge, this is the largest series of patients surgically treated with the endonasal endoscopic approach for sellar metastases. For these patients, the treatment focus should be on management modalities for increasing quality of life instead radical treatment options with survival benefit.

Three-Dimensional Modeling and Augmented and Virtual Reality Simulations of the White Matter Anatomy of the Cerebrum.

BACKGROUND: An understanding of the anatomy of white matter tracts and their 3-dimensional (3D) relationship with each other is important for neurosurgical practice. The fiber dissection technique contributes to this understanding because it involves removing the brain's white matter tracts to reveal their anatomic organization. Using this technique, we built freely accessible 3D models and augmented and virtual reality simulations of white matter tracts. OBJECTIVE: To define the white matter tracts of cadaveric human brains through fiber dissection and to make 2-dimensional and 3D images of the white matter tracts and create 3D models and augmented and virtual reality simulations. METHODS: Twenty cadaveric brain specimens were prepared in accordance with the Klingler method. Brain hemispheres were dissected step-by-step from lateral-to-medial and medial-to-lateral directions. Three-dimensional models and augmented reality and virtual reality simulations were built with photogrammetry. RESULTS: High-resolution 3D models and augmented reality and virtual reality simulations of the white matter anatomy of the cerebrum were obtained. These models can be freely shifted and rotated on different planes, projected on any real surface, visualized from both front and back, and viewed from various angles at various magnifications. CONCLUSION: To our knowledge, this is the first detailed study integrating various technologies (3D modeling, augmented reality, and virtual reality) for high-resolution 3D visualization of dissected white matter fibers of the entire human cerebrum.

Three-Dimensional Modeling and Augmented Reality and Virtual Reality Simulation of Fiber Dissection of the Cerebellum and Brainstem.

BACKGROUND: Surgeons must understand the complex anatomy of the cerebellum and brainstem and their 3-dimensional (3D) relationships with each other for surgery to be successful. To the best of our knowledge, there have been no fiber dissection studies combined with 3D models, augmented reality (AR), and virtual reality (VR) of the structure of the cerebellum and brainstem. In this study, we created freely accessible AR and VR simulations and 3D models of the cerebellum and brainstem. OBJECTIVE: To create 3D models and AR and VR simulations of cadaveric dissections of the human cerebellum and brainstem and to examine the 3D relationships of these structures. METHODS: Ten cadaveric cerebellum and brainstem specimens were prepared in accordance with the Klingler's method. The cerebellum and brainstem were dissected under the operating microscope, and 2-dimensional and 3D images were captured at every stage. With a photogrammetry tool (Qlone, EyeCue Vision Technologies, Ltd.), AR and VR simulations and 3D models were created by combining several 2-dimensional pictures. RESULTS: For the first time reported in the literature, high-resolution, easily accessible, free 3D models and AR and VR simulations of cerebellum and brainstem dissections were created. CONCLUSION: Fiber dissection of the cerebellum-brainstem complex and 3D models with AR and VR simulations are a useful addition to the goal of training neurosurgeons worldwide.

Development and Validation of a Novel Methodological Pipeline to Integrate Neuroimaging and Photogrammetry for Immersive 3D Cadaveric Neurosurgical Simulation.

Background: Visualizing and comprehending 3-dimensional (3D) neuroanatomy is challenging. Cadaver dissection is limited by low availability, high cost, and the need for specialized facilities. New technologies, including 3D rendering of neuroimaging, 3D pictures, and 3D videos, are filling this gap and facilitating learning, but they also have limitations. This proof-of-concept study explored the feasibility of combining the spatial accuracy of 3D reconstructed neuroimaging data with realistic texture and fine anatomical details from 3D photogrammetry to create high-fidelity cadaveric neurosurgical simulations. Methods: Four fixed and injected cadaver heads underwent neuroimaging. To create 3D virtual models, surfaces were rendered using magnetic resonance imaging (MRI) and computed tomography (CT) scans, and segmented anatomical structures were created. A stepwise pterional craniotomy procedure was performed with synchronous neuronavigation and photogrammetry data collection. All points acquired in 3D navigational space were imported and registered in a 3D virtual model space. A novel machine learning-assisted monocular-depth estimation tool was used to create 3D reconstructions of 2-dimensional (2D) photographs. Depth maps were converted into 3D mesh geometry, which was merged with the 3D virtual model's brain surface anatomy to test its accuracy. Quantitative measurements were used to validate the spatial accuracy of 3D reconstructions of different techniques. Results: Successful multilayered 3D virtual models were created using volumetric neuroimaging data. The monocular-depth estimation technique created qualitatively accurate 3D representations of photographs. When 2 models were merged, 63% of surface maps were perfectly matched (mean [SD] deviation 0.7 ± 1.9 mm; range -7 to 7 mm). Maximal distortions were observed at the epicenter and toward the edges of the imaged surfaces. Virtual 3D models provided accurate virtual measurements (margin of error <1.5 mm) as validated by cross-measurements performed in a real-world setting. Conclusion: The novel technique of co-registering neuroimaging and photogrammetry-based 3D models can (1) substantially supplement anatomical knowledge by adding detail and texture to 3D virtual models, (2) meaningfully improve the spatial accuracy of 3D photogrammetry, (3) allow for accurate quantitative measurements without the need for actual dissection, (4) digitalize the complete surface anatomy of a cadaver, and (5) be used in realistic surgical simulations to improve neurosurgical education.

Do antimicrobial stewardship programs improve the quality of care in ICU patients diagnosed with infectious diseases following consultation? Experience in a tertiary care hospital.

BACKGROUND: One of the most important public health concerns is the ever-growing problem of antibiotic resistance. Importantly, the rate of introduction of new molecules into clinical practice has slowed down considerably. Moreover, the rapid emergence of resistance shortens the effective 'lifespan' of these molecules. OBJECTIVE: The quality of care before and after active intervention and feedback was evaluated in patients diagnosed with sepsis/septic shock or ventilator-associated pneumonia (VAP) in the ICUs of Hacettepe University Adult and Oncology Hospitals. RESULTS: There was a significant increase in total scores. Significant improvements were achieved in the management of these patients in terms of requests for necessary diagnostic tests, and the prolonged infusion of beta-lactam agents. CONCLUSION: Implementation of an ASP in centers where antimicrobial management of ICU patients is largely controlled by infectious diseases specialists remains a feasible strategy that leads to better patient care.

Qlone®: A Simple Method to Create 360-Degree Photogrammetry-Based 3-Dimensional Model of Cadaveric Specimens.

BACKGROUND: Human cadavers are an essential component of anatomy education. However, access to cadaveric specimens and laboratory facilities is limited in most parts of the world. Hence, new innovative approaches and accessible technologies are much needed to enhance anatomy training. OBJECTIVE: To provide a practical method for 3-dimensional (3D) visualization of cadaveric specimens to maximize the utility of these precious educational materials. METHODS: Embalmed cadaveric specimens (cerebrum, brain stem, and cerebellum) were used. The 3D models of cadaveric specimens were built by merging multiple 2-dimensional photographs. Pictures were taken with standard mobile devices (smartphone and tablet). A photogrammetry program (Qlone®, 2017-2020, EyeCue Vision Technologies Ltd, Yokneam, Israel), an all-in-one 3D scanning and augmented reality technology, was then used to convert the images into an integrated 3D model. RESULTS: High-resolution 360-degree 3D models of the cadaveric specimens were obtained. These models could be rotated and moved freely on different planes, and viewed from different angles with varying magnifications. Advanced editing options and the possibility for export to virtual- or augmented-reality simulation allowed for better visualization. CONCLUSION: This inexpensive, simple, and accessible method for creating 360-degree 3D cadaveric models can enhance training in neuroanatomy and allow for a highly realistic surgical simulation environment for neurosurgeons worldwide.

68Ga-DOTATATE PET/CT in Pituitary Carcinoma.

ABSTRACT: A 47-year-old woman with atypical pituitary adenoma was referred to the neurosurgery department due to recent back pain. She had multiple transsphenoidal surgery, stereotactic body radiation, and 177Lu-DOTATATE therapy. Her spinal MRI showed multiple spinal masses. The patient underwent 68Ga-DOTATATE PET/CT to confirm the metastatic spread of the disease. PET/CT images showed increased uptake at the local recurrent tumor site and spinal metastases confirmed by biopsy to pituitary carcinoma. Our case presents the role of 68Ga-DOTATATE PET/CT in patients with pituitary carcinoma.

The Past, Present, and Future Statuses of Formerly Classified "Atypical Pituitary Adenomas": A Clinicopathological Assessment of 101 Cases in a Cohort of More than 1,000 Pure Endoscopically Treated Patients in Single Center.

Objective This study was aimed to assess the clinical aggressiveness of pituitary neoplasms that were previously defined as atypical adenomas. Methods A total of 1,042 pituitary adenomas were included in the study and 101 of them were diagnosed as atypical adenoma. Demographic characteristics, radiological evaluations, and clinical information were obtained from a computer-based patient database. Cases were categorized as atypical or typical using the criteria listed in 2004 Classification of Tumors of Endocrine Organs. Results The cure and reoperation rates did not show any statistically significant difference between the typical and atypical adenomas. However, a higher K i -67 labeling index was found to be associated with a higher rate of reoperation ( p = 0.008) in atypical adenomas. Of note, cavernous sinus invasion or parasellar extension was found to be associated with lower cure rates in patients with atypical pituitary adenomas ( p < 0.001 and p = 0.001, respectively). Conclusion Although atypical pituitary adenomas are known to be more invasive, this study demonstrated that the reoperation and cure rates are the same for typical and atypical adenomas. Our findings advocate for omitting the use of atypical adenoma terminology based solely on pathological evaluation. As stated in the 4th edition of the World Health Organization (WHO) classification, accurate tumor subtyping, evaluation of proliferation by means of mitotic count and K i -67 labeling index, and radiological and intraoperative assessments of tumor invasion should be taken into consideration in the management of such neoplasms.

Role of Hypofractionated Stereotactic Radiosurgery in Recurrent Pineal Parenchymal Tumors of Intermediate Differentiation: A Case Report and Review of the Literature.

A pineal parenchymal tumor of intermediate differentiation (PPID) is a rare entity, and optimal treatment is still unclear. Combined multimodality treatment should be considered in PPID due to high recurrence rates. Gross total resection is the first choice of treatment, however, it may not be feasible in every case due to location. Stereotactic radiosurgery (SRS) can be considered for the treatment of primary and recurrent disease, as it enables us to deliver a high radiation dose to the target while minimizing radiation exposure to normal tissue. In this report, we present a case treated with hypofractionated SRS for recurrent/metastatic PPID after the primary tumor was controlled with the combination of surgery and conventionally fractionated radiotherapy.

The Effect of Training, Used-Hand, and Experience on Endoscopic Surgery Skills in an Educational Computer-Based Simulation Environment (ECE) for Endoneurosurgery Training.

Today, virtual simulation environments create alternative hands-on practice opportunities for surgical training. In order to increase the potential benefits of such environments, it is critical to understand the factors that influence them. This study was conducted to determine the effects of training, used-hand, and experience, as well as the interactions between these variables, on endoscopic surgery skills in an educational computer-based surgical simulation environment. A 2-hour computer-based endoneurosurgery simulation training module was developed for this study. Thirty-one novice- and intermediate-level resident surgeons from the departments of neurosurgery and ear, nose, and throat participated in this experimental study. The results suggest that a 2-hour training during a 2-month period through computer-based simulation environment improves the surgical skills of the residents in both-hand tasks, which is necessary for endoscopic surgical procedures but not in dominant hand tasks. Based on the results of this study, it can be concluded that computer-based simulation environments potentially improve surgical skills; however, the scenarios for such training modules need to consider especially the bimanual coordination of hands and should be regularly adapted to the individual skill levels and progresses.

Technology-enhanced surgical education: attitudes and perceptions of the endoscopic surgery community in Turkey.

The education programme of surgery has unique problems. In this study, first, a literature review is conducted to cover the studies found in the literature reporting on the problems of surgical education. Additionally, a survey study is conducted with 31 participants, who are either currently enrolled in endoscopic surgery education programmes in Turkey or are experts in the field. Supportively semistructured individual interviews are also conducted with five participants. These data are collected to better understand the instructional methods being used, their problems and the participants' preferred methods to be used. Additionally, the participants' attitudes are also investigated regarding the use of new technologies to enhance the current education programmes. The results indicate that, in Turkey, surgical education programmes are still mostly offered in traditional ways while other educational methods are used in an extremely limited manner. In general, the authors emphasise that more research needs to be conducted to better understand the characteristics of the medical students and develop standards for surgical education programmes, educational tools specific for related surgical domains and guidelines for the curriculum integration. The results of this study aimed to guide the instructional system designers for the endoscopic surgery education programmes.

Construct and face validity of the educational computer-based environment (ECE) assessment scenarios for basic endoneurosurgery skills.

BACKGROUND: In neurosurgery education, there is a paradigm shift from time-based training to criterion-based model for which competency and assessment becomes very critical. Even virtual reality simulators provide alternatives to improve education and assessment in neurosurgery programs and allow for several objective assessment measures, there are not many tools for assessing the overall performance of trainees. This study aims to develop and validate a tool for assessing the overall performance of participants in a simulation-based endoneurosurgery training environment. METHODS: A training program was developed in two levels: endoscopy practice and beginning surgical practice based on four scenarios. Then, three experiments were conducted with three corresponding groups of participants (Experiment 1, 45 (32 beginners, 13 experienced), Experiment 2, 53 (40 beginners, 13 experienced), and Experiment 3, 26 (14 novices, 12 intermediate) participants). The results analyzed to understand the common factors among the performance measurements of these experiments. Then, a factor capable of assessing the overall skill levels of surgical residents was extracted. Afterwards, the proposed measure was tested to estimate the experience levels of the participants. Finally, the level of realism of these educational scenarios was assessed. RESULTS: The factor formed by time, distance, and accuracy on simulated tasks provided an overall performance indicator. The prediction correctness was very high for the beginners than the one for experienced surgeons in Experiments 1 and 2. When non-dominant hand is used in a surgical procedure-based scenario, skill levels of surgeons can be better predicted. The results indicate that the scenarios in Experiments 1 and 2 can be used as an assessment tool for the beginners, and scenario-2 in Experiment 3 can be used as an assessment tool for intermediate and novice levels. It can be concluded that forming the balance between perceived action capacities and skills is critical for better designing and developing skill assessment surgical simulation tools.

Descriptive Analysis of Sphenovomerine Suture and Its Importance in Neurosurgery.

PURPOSE: Articulation of rostrum of sphenoid bone with alae of vomer forms a schindylesis type of joint. The circumference of this joint, called sphenovomerine suture (SVS), is very important in establishing a reliable surgical field in the endoscopic transsphenoidal pituitary surgery. Because of its vital role in endoscopic transsphenoidal pituitary surgery, this radio-anatomical study was designed to establish the morphological properties of SVS. METHODS: In this study, the authors examined SVS in 235 patients (121 females and 114 males) on the computed tomography images of the paranasal sinus and made 4 measurements to describe SVS. RESULTS: The mean distance between superior margin of the upper labial philtrum and top of SVS was 6.66 ±â€Š0.43 cm for females and 7.44 ±â€Š0.54 cm for males. The distance between the top of SVS and dorsum sellae was 3.08 ±â€Š0.33 cm for females and 3.19 ±â€Š0.32 cm for males, the alae of vomer angle in the upper surface was 74.22 ±â€Š20.06° for females and 74.23 ±â€Š19.68° for males. The distance between the most lateral points of 2 alae of vomer was 0.99 ±â€Š0.17 and 1.01 ±â€Š0.19 cm for females and males, respectively. CONCLUSIONS: For an easy and successful operation, removal of the SVS is very important as it will provide a better view of the sellar base and make the management of the surgical instruments easier in the wider safe surgical field thus created.

Endoscopic Endonasal Transsphenoidal Surgery, A Reliable Method for Treating Primary and Recurrent/Residual Craniopharyngiomas: Nine Years of Experience.

OBJECTIVE: Craniopharyngioma resection is one of the most challenging surgical procedures. Herein, we describe our extended endoscopic endonasal transsphenoidal surgery (EETS) technique, and the results of 9 years of use on primary and recurrent/residual craniopharyngiomas. METHODS: This study reviewed 28 EETSs in 25 patients with craniopharyngiomas between January 2006 and September 2015. The patients were divided into 2 groups, newly diagnosed patients (group A, n = 15), and patients having residual or recurrent tumors (group B, n = 10). There was no significant difference between the groups in terms of the largest tumor diameter (P = 0.495), and all patients underwent EETS. The clinical and ophthalmologic examinations, imaging studies, endocrinologic studies, and operative findings for these cases were reviewed retrospectively. RESULTS: The number of gross total resections in group A was 13/15, and 7/10 in group B. Three of the patients developed postoperative cerebrospinal fluid leakage (all in group A). There were no neurovascular or ophthalmologic complications, and no meningitis or mortality was observed. CONCLUSIONS: There has been a notable increase in the use of EETS in the treatment of craniopharyngiomas during the last decade. Despite its increased use in the treatment of primary craniopharyngiomas, its implementation for recurrent or residual craniopharyngiomas has been viewed with suspicion. In this study, the results have been presented separately for primary and recurrent/residual craniopharyngiomas, so that the results can be compared. Overall, EETS is a reliable and successful surgical treatment method for primary and recurrent/residual craniopharyngiomas.