Navigating the calvaria with mobile mixed reality-based neurosurgical planning: how feasible are smartphone applications as a craniotomy guide?

OBJECTIVE: Virtual simulation and imaging systems have evolved as advanced products of computing technology over the years. With advancements in mobile technology, smartphones, and tablets, the quality of display and processing speed have gradually improved, thanks to faster central processing units with higher capacity. Integrating these two technologies into the fields of healthcare and medical education has had a positive impact on surgical training. However, contemporary neurosurgical planning units are expensive and integrated neuronavigation systems in operating rooms require additional accessories. The aim of this study was to investigate the compatibility of smartphone applications in augmented reality (AR)-based craniotomy planning, which can be available even in disadvantaged workplaces with insufficient facilities. METHODS: Thirty patients diagnosed with supratentorial glial tumor and who underwent operations between January 2022 and March 2023 were included in the study. The entire stages of the surgical procedures and the surgical plans were executed with neuronavigation systems. The patient CT scans were reconstructed using software and exported as a 3D figure to an AR-enhanced smartphone application. The evaluation of the application's success was based on the spatial relationship of the AR-based artificial craniotomy to the neuronavigation-based craniotomy, with each AR-based craniotomy scaled from 0 to 3. RESULTS: In the comparison between neuronavigation-based and AR fusion-based craniotomies, 8 of 30 (26.6%) patients scored 0 and were considered failed, 6 (20%) scored 1 and were considered ineffective, 7 (23.3%) scored 2 and were considered acceptable, and 9 (30%) scored 3 and were considered favorable. CONCLUSIONS: AR technology has great potential to be a revolutionary milestone of neurosurgical planning, training, and education in the near future. In the authors' opinion, with the necessary legal permissions, there is no obstacle to the integration of surgical technological systems with mobile technology devices such as smartphones and tablets that benefit from their low-budget requirements, wide-range availability, and built-in operating systems.

Transcallosal and endoscopic hybrid approach to a rare entity of pediatric intraventricular tumors-cribriform neuroepithelial tumor: a case report and literature review.

PURPOSE: Cribriform neuroepithelial tumor (CRINET) is a provisional category of intraventricular tumors, sharing similarities with AT/RTs, and there is a lack of data about its pathology, prognosis, and surgical approaches in the literature. We have been challenged to describe the surgical approach to a rare case of CRINET and describe the intraoperative features since none has been described before. Surgical resection and chemotherapy hold a great importance of favorable prognosis. METHODS: Twenty-month-old male with intraventricular tumor underwent transcallosal intraventricular tumor resection and endoscopic intraventricular second look stages. The tumor was initially considered choroid plexus carcinoma and histopathological results pointed CRINET. The patient also received Ommaya reservoir for intrathecal chemotherapy employment. The patient's preoperative and postoperative MRI scans and tumor's pathological features are described with a brief history of the disease in the literature. RESULTS: Lack of SMARCB1 gene immunoreactivity and presence of cribriform non-rhabdoid trabecular neuroepithelial cells led to the CRINET diagnosis. The surgical technique helped us to approach directly into the third ventricle and perform total resection and intraventricular lavage. The patient recovered without any perioperative complications and is consulted pediatric oncology for further treatment planning. CONCLUSION: With our limited knowledge on the matter, our presentation may provide an inside to the course and progress of the CRINET as a very rare tumor and may help to set a basis for future investigations focused on its clinical and pathological features. Long courses of follow-up periods are required for establishing treatment modules and assessing the responses to surgical resection techniques and chemotherapy protocols.

Single-institution comparative analysis for odontoid resection: posterior transaxis versus anterior transnasal approach.

OBJECTIVE: The resection of an upwardly migrated odontoid is most widely performed via an anterior endoscopic endonasal approach after the addition of posterior occipitocervical instrumentation. In patients with craniovertebral junction (CVJ) anomalies like basilar invagination (BI), surgery is usually achieved in two separate stages. However, the authors have recently introduced a novel posterior transaxis approach in which all the therapeutic goals of the surgery can be safely and effectively accomplished in a single-stage procedure. The aim of the current study was to compare the widely used anterior and the recently introduced posterior approaches on the basis of objective clinical results in patients who underwent odontoid resection for BI. METHODS: Patients with BI who had undergone odontoid resection were retrospectively reviewed in two groups. The first group (n = 7) consisted of patients who underwent anterior odontoidectomy via the standard anterior transnasal route, and the second group (n = 6) included patients in whom the novel transaxis approach was performed. Patient characteristics, neurological conditions, and modified Rankin Scale (mRS) scores at admission were evaluated. Operative time, changes in intraoperative neurophysiological monitoring, blood loss during surgery, odontoid resection rate, postoperative complications, and mortality were compared between the patient groups. RESULTS: Data were retrospectively reviewed for 13 patients who underwent odontoid resection, posterior CVJ decompression, and occipitocervical instrumentation at the Ankara University School of Medicine Department of Neurosurgery between 2009 and 2022. In the first group (n = 7), patients who underwent anterior odontoidectomy via the standard endonasal route, two serious complications were observed, pneumocephaly and basilar artery injury. In the second group (n = 6), patients in whom the novel transaxis approach was performed, only one complication was observed, occipital plate malposition. CONCLUSIONS: This study represents the results of what is to the authors' knowledge the first comparison of a novel approach with a widely used surgical approach to odontoid resection in patients with BI. The preliminary data support the successful utility of the transaxis approach for odontoid resection that meets all the operative therapeutic demands in a single-stage operation. Considering the diminished surgical risks and operative time, the transaxis approach may be regarded as a primary approach for the treatment of BI.

Transcranial endoscopic treatment of thalamic neuroepithelial cyst: case report and review of the literature.

Thalamic neuroepithelial cysts are rare, benign lesions. Thirteen cases have been published in eight articles. The most frequent symptoms are headache, hemiparesis, tremor and related signs of hydrocephalus such as gait disturbance, confusion, and Paranaud's syndrome. Surgical interventions include endoscopic fenestration, open surgery and stereotaxic biopsy or aspiration. We report a case of a 63-year-old woman who had headache and right hemiparesis for 1 week, but no hydrocephalus. We treated her with transcranial neuronavigation-guided endoscopic complete resection. The patient recovered completely after cyst removal.

Posterior fossa epidermoid tumors: a single-center study and proposed classification system.

BACKGROUND: Epidermoid tumors of the cerebellopontine angle and posterior fossa account for approximately 1% of all intracranial tumors. Classifications that may guide surgical planning in the current neurosurgical practice are lacking. This study aimed to focus on the surgical outcome and suggest a classification system that may aid neurosurgeons in determining the goal of resection to minimize morbidity and mortality rates. METHODS: The study population comprised patients who underwent surgery and follow-up for tissue-proven epidermoid tumors between 2015 and 2020. Patients' data, including demographic features, clinical symptomatology, the extent of surgical resection, and postoperative outcomes, were retrospectively evaluated. A new classification system was designed based on the anatomical-radiological findings and was evaluated in terms of clinical symptomatology, radiological features, surgical approach, and postoperative outcomes. RESULTS: The patient population comprised 22 women (57.9%) and 16 men (42.1%), with a mean age of 34.9 years. A practical classification system based on the radiological-anatomical vertical (1, 2, and 3) and horizontal (a, b, and c) tumor extensions was designed. No significant differences were found in the patients in terms of sex/age. The most commonly observed symptom was gait disturbance (34.2%). The preoperative tumor diameter was significantly larger in the subtotal resection (STR) group than in the gross total resection (GTR) and near-total resection (NTR) groups. Significantly more cistern involvement was observed in the STR group than in the GTR group. The GTR, NTR, and STR rates were higher in grade 1, 3, and 2 cases, respectively. The subgroup 'a' was correlated with higher resection rates (GTR and NTR), whereas the subgroup 'b' was correlated with STR. CONCLUSIONS: Our suggested classification system represents a simple and practical model that may guide neurosurgeons in predicting the goal of resection during surgical planning and in minimizing potential morbidity.

Facial nerve outcome and extent of resection in cystic versus solid vestibular schwannomas in radiosurgery era.

OBJECTIVE Cystic vestibular schwannomas (CVSs) are a subgroup of vestibular schwannomas (VSs) that are reported to be associated with unpredictable clinical behavior and unfavorable postoperative outcomes. The authors aimed to review their experience with microsurgical treatment of CVSs in terms of extent of resection and postoperative facial nerve (FN) function and compare these outcomes with those of their solid counterparts. METHODS Two hundred-eleven VS patients were treated surgically between 2006 and 2017. Tumors were defined as cystic when preoperative neuroimaging demonstrated cyst formation that was confirmed by intraoperative findings. Solid VS (SVSs) with similar classes were used for comparison. Clinical data of the patients were reviewed retrospectively, including clinical notes and images, as well as operative, pathology, and neuroradiology reports. RESULTS Thirty-two patients (20 males and 12 females) with a mean age of 52.2 years (range 17-77 years) underwent microsurgical resection of 33 CVSs (mean size 3.6 cm, range 1.5-5 cm). Forty-nine patients (26 males and 23 females) with a mean age of 49.9 years (range 21-75 years) underwent microsurgical resection of 49 SVSs (mean size 3 cm, range 2-4.5 cm). All operations were performed via either a retrosigmoid or a translabyrinthine approach. Gross-total resection was achieved in 30 cases in the CVS group (90.9%) and 37 in the SVS group (75.5%). The main reason for subtotal and near-total resection was adherence of the tumor to the brainstem and/or FN in both groups. None of the patients with subtotal or near-total resection in the CVS group demonstrated symptomatic regrowth of the tumor during the mean follow-up period of 41.6 months (range 18-82 months). The FN was anatomically preserved in all patients in both groups. Good FN outcomes were achieved in 15 of CVS (grade I-II; 45.5%) and 35 of SVS (71.4%) surgeries at discharge. Good and fair FN functions were noted in 22 (grade I-II; 81.5%) and 5 (grade III only; 18.5%) of the CVS patients, respectively, at the 1-year follow-up; none of the patients showed poor FN function. CONCLUSIONS Surgery of CVSs does not necessarily result in poor outcomes in terms of the extent of resection and FN function. Special care should be exercised to preserve anatomical continuity of the FN during surgery, since long-term FN function outcomes are much more satisfactory than short-term results. High rates of gross-total resection and good FN outcomes in our study may also suggest that microsurgery stands as the treatment of choice in select cases of large CVSs and SVSs in the era of radiosurgery.

Preoperative Exposure of Sigmoid Sinus Trajectory in Posterolateral Cranial Base Approaches Using a New Landmark Through a Neurosurgical Perspective.

The location of burr holes in posterolateral cranial base approaches should be appropriate to provide an adequate operative field, and surgical freedom is crucial for bone window opening. The aim of this study was to search for more convenient and easily detectable landmarks in comparison with current landmarks in posterolateral cranial base surgery. Twenty 3-dimensional reconstructed head and neck computed tomography angiography images (group 1) and 20 cadaver heads (group 2) were evaluated. An imaginary line connecting the angle of the mandible and the mastoid tip was extended upward. A second line passing through the lateral edge of the zygomatic arch was also extended posteriorly. The authors examined if the first line met with the sigmoid sinus throughout its course and determined the location of the intersection point of these 2 lines relative to the sigmoid-transverse sinus junction. The intersection point did not correspond to the sinus region in 3 images from group 1 and 4 specimens from group 2. The matching of the mandibula-mastoid line trajectory with the sigmoid sinus course was unacceptable in 4 images and 5 cadavers. For venous anatomy preservation and anatomic skull base fossa orientation during posterolateral cranial base approaches, upward extension of the mandibula-mastoid line can be a proper landmark for surgical planning in this region. The authors' proposed superficial anatomical line and intersection point over the skull could be used as a reliable indicator for the external projection of the sigmoid sinus and an appropriate initial burr-hole location.

Single-Center Surgical Experience of the Treatment of Craniopharyngiomas With Emphasis on the Operative Approach: Endoscopic Endonasal and Open Microscopic Transcranial Approaches.

This study aimed to report the authors' single-center clinical experience about craniopharyngiomas and discuss surgical outcomes of these patients according to the type of surgical approach (endoscopic endonasal or open microscopic transcranial approach).Twenty-four patients diagnosed with craniopharyngiomas between May 2013 and April 2017 were considered for inclusion. The patients were divided into 2 groups according to the surgical approach (open transcranial microscopic approach [group A] and endoscopic endonasal approach [group B]). These groups were compared in terms of postoperative surgical outcome scores (extent of tumor removal, visual deficit, hydrocephalus, metabolic disorders, and Glasgow coma scale) and hospitalization interval.There was no patient of mortality in both groups. In this study, 4 of the 13 patients in group A and 9 of the 11 patients in group B underwent gross total resection. However, 1 patient in group B underwent repair because of cerebrospinal fluid leakage postoperatively. In addition, 1 patient in group A had a wound healing problem postoperatively. The postoperative outcome scores were 9.5 in group A and 11.5 in group B. The hospitalization interval in group A (range, 7-9 days) was longer than that in group B (range, 5-7 days).The endoscopic endonasal approach should be considered the first-line surgical treatment modality in patients with a preliminary diagnosis of craniopharyngioma in terms of low complication risk, minimal invasiveness, and better outcome scores. Open microscopic transcranial procedures may be combined with this approach in a single session for challenging cases.

Surgical outcomes of decompressive laminectomy by transspinous approach for degenerative lumbar spinal stenosis.

OBJECTIVE: To assess clinical and radiographical outcomes of transspinous decompression technique for the treatment of degenerative central lumbar spinal stenosis. METHODS: The single-centre, non-randomised interventional, prospective, observational study was conducted Neurosurgery Clinic of Mazhar Osman Research and Training Hospital for Psychiatry and Neurology, Istanbul, Turkey from May 2013 and May 2016 and comprised adult patients with refractory symptoms from degenerative central lumbar spinal stenosis who underwent lumbar spinous processsplitting laminectomy. Pre- and post-operative Oswestry Disability Index score, visual analogue scale for overall pain, maximum walking distance and anteroposterior diameter of the spinal canal on magnetic resonance imaging were assessed on follow up examination. SPSS 22 was used for data analysis. RESULTS: Of the 89 patients, 7(7.86%) were lost to follow-up, while 82(92.14%) completed the study. Of them, 42(51%) were women and 40(49%) were men. Overall mean age was 63.86±10.02 years (range: 40-85 years). A total of 95 transspinous decompressive laminectomies were performed. Mean number of decompressed spinal segments was 1.16. Median duration of surgical procedure was 45 min, while mean length of hospital stay was 1.22±0.47 days. Mean decrease in pre operative Oswestry Disability Index scoreat 1-year was 56.4% and overall visual analogue scale was 55.9%.Mean increase of 155.2% was documented over pre-operative maximum walking distance. Radiological assessment revealed a 40.7% increase in the mean and anteroposteriordiameter of the spinal canal at the level of the target lesion. The improvement in various parameters was statistically significant (p<0.001).. CONCLUSIONS: Lumbar spinous process-splitting laminectomy led to significant improvement with respect to patient-reported perceived recovery, functional disability and radiological evidence of effective surgical decompression in patients with lumbar spinal stenosis..

Resection of middle petroclival meningioma via combined anterior transpetrosal and retrosigmoid approaches at two separate stages: 3D operative video.

Surgical access to the petroclival region poses a challenge to neurosurgeons. A wide range of approaches has been demonstrated in the past. In this video, the authors present a 69-year-old male patient who presented with 3-month history of worsening left-sided numbness. The tumor was totally removed in 2 sessions via anterior transpetrosal and retrosigmoid approaches, respectively. The authors demonstrate 2 separate skull base approaches to resect a petroclival meningioma and discuss pitfalls and problems of management for challenging meningiomas. The authors suggest that surgical approaches to petroclival meningiomas should be selected based on an individual case. A skull base team should be versatile in performing all these approaches. The video can be found here: https://youtu.be/BCVrn3TeNvE .

A rare and unexpected clinical progress and location on a primary extradural spinal hydatid cyst in a pediatric patient: a case report.

BACKGROUND: Involvement of spine in patients with hydatid disease (HD) is less than 1% and primary intra-spinal extradural HD is extremely rare. Although this disease is introduced as benign pathology according to its clinical presentation and biological behavior, intraoperative rupture of the cyst may aggravate the patients' outcome in the long-term especially in pediatric patient population. CASE PRESENTATION: We report a 9-year-old girl who presented a progressive neurological deterioration due to an enlargement of a ventrally located extradural hydatid cyst within the thoracic spinal canal. Total removal of the cyst was achieved by preserving the capsule integrity for preventing potential seeding. Our preoperative initial diagnosis based on the radiological findings was confirmed as cyst hydatid histopathologically. CONCLUSION: Cyst hydatid should be considered in the differential diagnosis of the presence of homogenous cystic lesions with regular shape inside the spinal canal especially in patients from endemic region. To our knowledge, this pediatric patient is the first case of cyst hydatid located ventral side of the spinal cord extradurally located inside the spinal canal showing no extension.

Mixed Reality Assisted Navigation Guided Microsurgical Removal of Cranial Lesions.

AIM: To demonstrate the possible use of mixed reality (MR) technology in neurosurgery for multiple purposes, including preoperative planning, training, and three-dimensional (3D) navigation. MATERIAL AND METHODS: Using magnetic resonance imaging (MRI) and computed tomography (CT), 3D holographic images of three patients were created and inspected using a remote control. Preoperative planning was performed in a conference room using holographic images. Intraoperatively, the 3D images were matched and the adjacent structures were examined. RESULTS: The MR System (MRS) was a useful tool for preoperative planning and intraoperative navigation during the cranial intervention. It reduces operative time, decreases complication rates, increases surgical success, and enhances surgical outcomes. Eventually, MRS may be more economical. CONCLUSION: The MRS can be used for intraoperative navigation by displaying a 3D hologram at the surgeon's fingertips and for preoperative 3D examination of the lesions and its surrounding structures. The MRS enhances surgical efficacy, reduces healthcare costs, and has a shorter learning curve than the conventional methods. It also enables customized patient-specific surgery.

Investigating the Effects of Trigeminal Impression and Internal Acoustic Opening Morphology Differences for Possible Surgical Applications.

PURPOSE: The exhaustive information regarding the types of trigeminal pore (TP) or trigeminal impression (TI), internal acoustic opening (IAO), and related surgical approaches is lacking in the literature. Therefore, this study is performed to further elucidate the types of TP or TI, IAO, and the relationships with critical surgical landmarks in the skull base. METHODS: Trigeminal impression (TI) and internal acoustic opening (IAO) found in 11 dry skulls, 24 right temporal bones, and 25 left temporal bones were examined on both sides to define their relationship to each other and nearby structures. The age and sex of these bones were not identified. Besides these, 77 skulls were examined by radiologic imaging methods. These skulls were identified by gender. RESULTS: According to test results, there was a significant difference between the left and right internal acoustic opening in the case of horizontal dimension (HD). The left HD-IAO is bigger than the right one. In addition, right HD-IAO, vertical dimension (VD) of right internal acoustic opening, left HD-IAO, and left VD-IAO values differed significantly in male and female patients. CONCLUSIONS: Investigating the relationship of TI and IAO with relevant structures suggests that surgical approaches involving the TP and IAO indicated that surgical approaches considering the TI and IAO variations may be used in the development of surgical processes and primary surgical interventions.

Evaluation of Neurosurgical Emergencies in the Pediatric Emergency Department: Clinical Warning Signs.

BACKGROUND: We aimed to evaluate the patients who underwent neuroimaging with suspicion of neurosurgery pathology and identify the clinical warning signs for the early recognition of neurosurgical emergencies. METHODS: Patients aged one month to 18 years who underwent neuroimaging with a preliminary diagnosis of intracranial pathology requiring emergency surgery and symptom duration less than one month were included in the study. Patients were divided into three groups according to their definitive diagnosis as neurosurgical emergencies, neurological emergencies, and nonurgents. RESULTS: A total of 140 patients were included in the study (the median age was 8 [interquartile range IQR 3 to 13] years and 52.8% were male). Neurosurgery emergency group and neurological emergency group were significantly younger than the nonurgent group (P < 0.001). Vomiting, meningeal irritation findings, and papilledema (grade 2 and above) were more common in the neurosurgical emergency group (P 0.029, 0.023, and < 0.001, respectively). For neurosurgical emergencies, in the presence of papilledema (grade 2 and above) and focal neurological deficit, the specificity was 99.2%, positive predictive value (PPV) 83.3%, negative predictive value (NPV) 88.1%, and odds ratio (OR) 36.8 (P < 0.001, confidence interval [CI] 4.04 to 336.0); in the presence of altered consciousness and focal neurological deficit, the specificity was 97.5%, PPV 50%, NPV 86.6%, and OR 6.4 (P = 0.014, CI 1.20 to 34.4). CONCLUSIONS: Younger age, presence of vomiting, signs of meningeal irritation, papilledema grade 2 and above, and altered consciousness are the crucial "warning signs" of a potential neurosurgical emergency.

Hybrid Positron Emission Tomography and Magnetic Resonance Imaging Guided Microsurgical Management of Glial Tumors: Case Series and Review of the Literature.

In this case series, we aimed to report our clinical experience with hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI) navigation in the management of recurrent glial brain tumors. Consecutive recurrent neuroglial brain tumor patients who underwent PET/MRI at preoperative or intraoperative periods were included, whereas patients with non-glial intracranial tumors including metastasis, lymphoma and meningioma were excluded from the study. A total of eight patients (mean age 50.1 ± 11.0 years) with suspicion of recurrent glioma tumor were evaluated. Gross total tumor resection of the PET/MRI-positive area was achieved in seven patients, whereas one patient was diagnosed with radiation necrosis, and surgery was avoided. All patients survived at 1-year follow-up. Five (71.4%) of the recurrent patients remained free of recurrence for the entire follow-up period. Two patients with glioblastoma had tumor recurrence at the postoperative sixth and eighth months. According to our results, hybrid PET/MRI provides reliable and accurate information to distinguish recurrent glial tumor from radiation necrosis. With the help of this differential diagnosis, hybrid imaging may provide the gross total resection of recurrent tumors without harming eloquent brain areas.

Does the Extent of Rod Bending and Actual Lumbar Lordosis Mismatch Affect Quality of Life?

BACKGROUND: To evaluate any mismatch between rod bending and actual lordosis during posterior lumbar instrumentation and its effects on the quality of life (QOL) of patients. METHODS: Patient records for posterior lumbar fusion in 2018-2023 were retrospectively reviewed. The radiologic parameters consisted of pelvic incidence, sacral slope, L1S1 lumbar lordosis, lumbosacral angle, the distance between the posterior wall of the vertebra and the rod, lordosis of the rod. The postoperative QOL of patients was assessed using Oswestry Disability Index. The patients were grouped postoperative into Group-1 (minimal/moderate disability) and Group-2 (severe disability/crippled/bed bound). RESULTS: Total of 133 patients were included; 99 women, 34 men. The difference was significant for patients with diabetes to be presented in the more disabled Group-2. The distance between the posterior vertebral wall and the rod was found to be short in Group-2. Preoperative and postoperative sagittal lumbar Cobb angles were significantly higher in Group-2. The changing degree of pain was found to score high in Group-2. The postoperative visual analog scale was high in Group-2. The difference between the preoperative and postoperative lumbar sagittal Cobb and rod Cobb-angles was found to be high in Group-2. CONCLUSIONS: The results of our study confirm the importance of considering the preoperative actual lumbar lordosis during bending and maintaining it as much as possible. To our knowledge, this is the first study that evaluated the effect of rod bending on quality of life (QOL) and supports that this might be affected in case of any mismatches.

Prediction of Meningioma Grade Using Hematological Parameters.

OBJECTIVE: Predicting the aggressiveness of meningiomas may influence the surgical strategy timing. Because of the paucity of robust markers, the systemic immune-inflammation (SII) index is a novel biomarker to be an independent predictor of poor prognosis in various cancers including gliomas. We aimed to investigate the value of SII as well as neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) indices in predicting prognosis. METHODS: Records including demographic, clinical, and laboratory data of patients operated on due to intracranial meningioma in 2017-2023 were retrospectively reviewed. RESULTS: A total of 234 patients were included in this study. All of SII index, NLR, and PLR values at presentation were significantly higher in grade ≥2 meningiomas. A positive correlation was observed between SII index and Ki67 index (r=0.313; P<0.001); between NLR and Ki67 index (r=0.330; P<0.001); and between PLR and Ki67 index (r=0.223; P<0.01). SII index (optimal cutoff level >618), NLR (optimal cutoff level >3.53), and PLR (optimal cutoff level >121.2) showed significant predictive values. CONCLUSIONS: This is the first study to assess the prognostic value of the SII index in patients with intracranial meningiomas. Increased SII index, NLR and PLR were correlated with higher grade and higher Ki-67 index. They also harbor the potential to screen patients that may need more aggressive treatments or more frequent follow-up examinations.

Carotid artery stenting for symptomatic carotid near occlusions: Feasibility, safety and outcome analysis.

INTRODUCTION: Extracranial internal carotid stenosis (EICS) is a well-established cause of stroke. Carotid near-occlusion (CNO), either distally collapsed or not, is a rare sub-type of EICS with conflicting data regarding the necessity for treatment. The aim of this study is to evaluate the results of carotid artery stenting (CAS) for patients with symptomatic CNOs. MATERIAL AND METHODS: Institutional review board (I06-420-23) approval was obtained for this retrospective study. Consecutive data from January 2019 to January 2023 was obtained. Sixty-five patients underwent 66 procedures for symptomatic CNOs. Diagnosis of CNOs were made with DSA images. Treatment decisions were made by a multidisciplinary team. Patient data including age, gender, clinical presentation, affected side, complications (initial/ follow-up), and pre and post mRS scores were recorded and analyzed. RESULTS: There were 22 female and 43 male patients with symptomatic CNOs (mean age: 71.52 ± 9.32 years). The mean time from symptom-to-treatment was 3.91 weeks ± 3.74 weeks (ranging from 0 to 20 weeks). There were eight events recorded in the 30 days period after CAS; five (7.7%) were cerebral hyperperfusion syndrome (one causing haemorrhage) and three (4.5%) ischemic complications. Permanent neurologic deficit rate was 6% and 61 patients (94%) mRS scores were unchanged during last follow-up. Mean follow-up period was 22.94 ± 16.67 months (ranging from 0.5 to 60 months). CONCLUSION: Our study demonstrated that in the complex population of patients with symptomatic CNOs, CAS is a feasible option with acceptable rate of permanent neurologic deficits. Further studies are needed to assess its safety and long-term efficacy.

New practical landmarks to determine sigmoid sinus free zones for suboccipital approaches: an anatomical study.

Literature defines the landmarks to identify the courses and locations of the transverse and sigmoid sinuses on the outer surface of the skull and inner surface of the scalp. These natural landmarks may only be helpful after skin incision and are inadequate to determine the length and size of the skin incision. Still, there is a need to identify palpable landmarks easily to determine the ideal location to open the initial burr hole before an operation. Twenty-eight dried adult human skulls and 2 cadavers were evaluated. The zygomatic root, the inion, and the mastoid process were identified on the external, and the grooves for sigmoid and transverse sinuses, on the internal surfaces. The distances between the 3 landmarks and the midpoints, and the shortest distances of the midpoints to the border of the groove for sigmoid sinus and groove for transverse sinus were measured. Statistically significant differences were evaluated for both sides. Based on the measurements, the defined "artificial landmarks" can be considered safe points that involve no vascular structures and may be used to perform the initial burr hole during posterolateral approaches. Identification of the midpoints and palpation of the defined landmarks easily before the operation render the study feasible and practical unlike with natural landmarks. To avoid venous injury, the midpoints of mastoid-inion line and zygomatic root-inion line can be used safely in skin incision during posterior fossa approaches and craniotomy.

A new surgical path planning framework for neurosurgery.

BACKGROUND: Despite using a variety of path-finding algorithms that use tracts, the most significant advancement in this study is considering the values of all brain areas by doing atlas-based segmentation for a more precise search. Our motivation comes from the literature's shortcomings in designing and implementing path-planning methods. Since planning paths with curvatures is a complex problem that requires considering many surgical and physiological constraints, most path-planning strategies focus on straight paths. There is also a lack of studies that focus on the complete structure of the brain with the tracks, veins, and segmented areas. Instrument dependence is another inadequacy of the methods proposed in the literature. AIMS: The aim of this study is to design a new surgical path planning framework that helps to plan the surgical path independently of the instrument, considers the entire structure of the brain, and allows curvilinear surgical paths. Thus, neurosurgeons can generate patient-specific possible optimal surgical pathways before the neurosurgical procedure. MATERIALS & METHODS: The proposed framework includes different path-finding algorithms (Dijkstra, A*, and their aggressive variants) that find optimal paths by taking the risk scores (surgeons assessed all the segmented regions, considering the extent of damage. In this evaluation, scores ranged from "0 to 10," with the most critical areas receiving a score of "10," while the least possible affected areas were assigned a score of "0") for sensitive brain areas into consideration. For the tract image processing the framework includes fractional anisotropy (FA), relative anisotropy (RA), spherical measure (SM), and linear measure (LM) methods. RESULTS: This is the first paper to handle tracts and atlas-based segmentation of the human brain altogether under a framework for surgical path planning. The framework has a dynamic structure that gives the flexibility to add different path-finding algorithms and generate different widths of surgical pathways. Moreover, surgeons can update the score table to guarantee minimally invasive surgery. The output file format of all the extracted surgical paths is NRRD, so it can be easily visualised, analysed, or processed over the third part software tools. DISCUSSION: In this study, we generated many possible surgical pathways then these pathways were evaluated by the surgeons the results were impressive because the framework could identify surgical pathways used in real-world surgery that correspond to the standard pathways such as anterior transsylvian, trans sulcal, transgyral, and sub-temporal. CONCLUSION: This study proposes a new surgical path planning framework for neurosurgery. Moreover, in the future by adding/adopting different parameters (such as operation time, and short and long-term complications after surgery) to the proposed framework, it would be possible to find new surgical pathways for difficult surgical conditions.