Revision Cranioplasty with Three-dimensional Custom-made Titanium Implants in Patients with Failed Cranioplasty.

OBJECTIVE: Graft failure is a common complication of cranioplasty. Revision cranioplasty is required to overcome this complication. However, no previous studies have reported outcomes in revision cranioplasty with 3-dimensional (3D) custom-made titanium implants. We describe our experience with 3D titanium implants in patients with revision cranioplasty. METHODS: We evaluated 43 consecutive patients between January 2011 and December 2019 who underwent revision cranioplasty using 3D custom-made titanium implants. The 3D image of the patient's cranium and the plan to close the cranium defect were created in a virtual environment using software programs. Demographic and radiologic features were compared based on the materials used in the initial cranioplasty. RESULTS: Previous material was autologous graft (AG) in 27 patients and polymethyl methacrylate (PMMA) in 16 patients. The mean time without revision cranioplasty is longer in patients with PMMA implants than in patients with AG. There was no statistically significant difference in the length of hospital stay between patients with PMMA implants and patients with AG. There were no postoperative adverse events such as infection, wound dehiscence, convulsions, or epidural hematoma in 38 patients during hospitalization. Wound dehiscence developed in 5 patients and surgical repair was required in one. CONCLUSIONS: Initial cranioplasty with PMMA provides a longer time period than the AG before the revision. However, both of them have similar outcomes based on length of hospital stay and cranial defect area. Custom-made 3D titanium implant is a good option for revision cranioplasty to prevent implant failure and reduce patients' cosmetic concerns.

Simultaneous Closure of Bilateral Cranial Defects Using Custom-Made 3D Titanium Implants: A Single Institution Series.

AIM: To investigate the outcomes of the simultaneous closure of bilateral cranial defects using custom-made three-dimensional (3D) titanium implants. MATERIAL AND METHODS: Demographic data of 26 patients with bilateral cranial defects who underwent cranioplasty using the 3D custom-made titanium implants in our clinic between 2017 and 2022 were retrospectively reviewed. Data on the area of cranium defect, the time interval between last cranial surgery and cranioplasty, postoperative complications, etiology of the cranium defect, and hospitalization of the patient were statistically evaluated. RESULTS: The incidence of bilateral cranioplasty was 19.11%. The gender distribution of patients was 4 (15.4%) female and 22 (84.6%) male, with a mean age of 29.08 ± 14.65 years. The mean defect area was 35.0 ± 19.03 and 29.24 ± 22.51 cm2 on the right and left sides, respectively. The etiology of the cranium defect was gunshot wounds in 12 patients, and 14 patients had a history of trauma-related injuries such as falls and vehicle accidents. Eight patients had a history of failed cranioplasty with autologous bone. Postoperative complications were wound dehiscence in two patients and diffuse cerebral edema in one patient. No mortality was recorded. CONCLUSION: The custom-made cranioplasty is feasible for simultaneous closure of bilateral cranial defects. Many complications can be prevented by careful preoperative evaluation before surgery and an appropriate implant selection for the patient.

Comparison of Surgical Techniques for Intracranial Arachnoid Cysts: A Volumetric Analysis.

AIM: To compare the volumetric changes of intracranial arachnoid cysts (IACs) in different surgical techniques. MATERIAL AND METHODS: Sixty-six patients who underwent IAC surgery in our department between 2010 and 2020 were studied retrospectively. Based on the surgical technique, clinical and volumetric changes, postoperative complications, recurrence rates, and length of hospital stay were statistically compared. RESULTS: Microsurgical fenestration (MF) was performed on 32 (48.5%) patients, endoscopic fenestration (EF) on 17 patients, cystoperitoneal shunt (CPS) on 11 patients, and EF + CPS in six patients. The mean IAC volume change rate was 68.54 mL, and the mean cyst volume change rate was 40.68%. The MF technique produces a significantly greater mean cyst volume change than the EF technique. The mean volume change in sylvian IAC is 4.8 times greater than in posterior fossa IAC, a significant difference. The mean cyst volume change is four times greater in patients with skull deformity than in patients with balance loss, and this difference is statistically significant. In patients with cranial deformity, the mean cyst volume change is 2.6 times greater than in patients with neurological dysfunction. This difference is also statistically significant. The volume of IAC decreased more in patients with postoperative complications, with a significant difference between the postoperative complication and the change in IAC volume. CONCLUSION: MF can achieve better volumetric reduction in IAC, particularly in patients with sylvian arachnoid cysts. However, more volumetric reduction increases the risk of postoperative complications.

Risk Factors and Surgical Treatment Options for Intracranial Infections.

AIM: To present our experience on intracranial infections, and to determine the possible locations as well as the risk factors for surgical treatment. MATERIAL AND METHODS: Over 13 years, 103 patients with intracranial infection underwent surgical evacuation. Seventy-one (68.9%) patients were men, and the mean age was 38.57 years. For intracranial infections, direct and indirect microbiological identification methods were used. The clinical and radiological data of patients were retrospectively analyzed and compared statistically based on the type of infection, location, history of previous surgery, comorbid diseases, and demographic features of the patients. RESULTS: Forty-six (44.7%) patients had intraparenchymal abscess, 25 (24.3%) had subdural empyema, and 32 (31.0%) had epidural empyema. Emergent surgical evacuation was performed in 60 (58.25%) patients. Microbiological agents were not isolated in 26 (25%) patients, while multiple microorganisms were isolated in 17 (16.5%) patients. Intraparenchymal abscesses are more common in the frontal lobe and cerebellum, while subdural empyemas are located more frequently in the frontoparietal region. There was no significant difference between intracranial infection and age, gender, history of surgery, and preoperative antibiotic use. However, a statistically significant relationship between intracranial infection, history of previous surgery, and the patient?s comorbid disease was found. Specifically, intraparenchymal abscesses were more frequently detected in immunocompromised patients, and subdural empyemas were common in patients with previous tumor surgery. CONCLUSION: Brain abscesses commonly develop in the frontal lobe and cerebellum. Patients who underwent previous cranial surgery and patients with comorbid diseases are more prone to intracranial infections. Large abscesses with significant edema are best candidates for emergent surgical evacuation.

Resection of intra- and paraventricular malignant brain tumors using fluorescein sodium-guided neuroendoscopic transtubular approach.

BACKGROUND: The requirement of brain retraction and difficulty in distinguishing the tumor demarcation are challenging in conventional approaches to intra- and paraventricular malignant tumors (IV-PVMTs). Tubular retractors can minimize the retraction injury, and fluorescein-guided (FG) surgery may promote the resection of tumors. Our aim is to evaluate the feasibility, safety, and effectiveness of fluorescein-guided endoscopic transtubular surgery for the resection of IV-PVMTs. METHODS: Twenty patients with IV-PVMTs underwent FG endoscopic transtubular tumor resection. Fluorescein sodium was administered before the dural opening. The intraoperative fluorescence staining was classified as "helpful" and "unhelpful" based on surgical observation. Extent of resection was assessed using postoperative magnetic resonance imaging. Karnofsky Performance Status (KPS) score was used to evaluate the general physical condition of patients. RESULTS: There were 9 glioblastomas, 4 anaplastic astrocytomas and 7 metastatic tumors. "Helpful" fluorescence staining was observed in 16(80%) of 20 patients. Gross total resection was achieved in 16(80%) cases, near-total in 3(15%) cases, and subtotal in 1 (5%) case. No intra- or postoperative complications related to the fluorescein sodium occurred. The median preoperative KPS score was 83, and the median KPS score 3-month after surgery was 88. CONCLUSION: FG endoscopic transtubular surgery is a feasible technique for the resection of IV-PVMTs. It may be a safe and effective option for patients with these tumors. Future prospective randomized studies with larger samples are needed to confirm these preliminary data.

Fluorescein Sodium-Guided Neuroendoscopic Resection of Deep-Seated Malignant Brain Tumors: Preliminary Results of 18 Patients.

BACKGROUND: Deep-seated intracranial lesions are challenging to resect completely and safely. Fluorescence-guided surgery (FGS) promotes the resection of malignant brain tumors (MBTs). Classically, FGS is performed using microscope equipped with a special filter. Fluorescence-guided neuroendoscopic resection of deep-seated brain tumors has not been reported yet. OBJECTIVE: To evaluate the feasibility, safety, and effectiveness of the fluorescence-guided neuroendoscopic surgery in deep-seated MBTs. METHODS: A total of 18 patients with high-grade glioma (HGG) and metastatic tumor (MT) underwent fluorescein sodium (FS)-guided neuroendoscopic surgery. Tumor removal was carried out using bimanual microsurgical techniques under endoscopic view. The degree of fluorescence staining was classified as "helpful" and "unhelpful" based on surgical observation. Extent of resection was determined using magnetic resonance imaging (MRI). Karnofsky Performance Status (KPS) score was used for evaluation of general physical performances of patients. RESULTS: A total of 11 patients had HGG, and 7 had MT. No technical difficulty was encountered regarding the use of endoscopic technique. "Helpful" fluorescence staining was observed in 16 patients and fluorescent tissue was completely removed. Postoperative MRI confirmed gross total resection (88.9%). In 2 patients, FS enhancement was not helpful enough for tumor demarcation and postoperative MRI revealed near total resection (11.1%). No complication, adverse events, or side effects were encountered regarding the use of FS. KPS score of patients was improved at 3-mo follow-up. CONCLUSION: FS-guided endoscopic resection is a feasible technique for deep-seated MBTs. It is safe, effective, and allows for a high rate of resection. Future prospective randomized studies are needed to confirm these preliminary data.

Extended endonasal endoscopic approach for anterior midline skull base lesions.

AIM: In recent years, extended endoscopic endonasal approach (EEEA) has been used as an alternative to transcranial approaches in the treatment of anterior midline skull base lesions. We retrospectively reviewed our cases operated using this technique and compared the results with current literature. METHOD: The data of 24 patients who were operated using EEEA in our department between 2010-2018 were retrospectively analyzed. The lesions were located in the midline between the posterior wall of the frontal sinus and tuberculum sella. Tumor locations, histopathological diagnoses, surgical techniques, outcomes and complications were documented. RESULTS: Eleven patients were female and 13 were male. Their ages ranged between 18-75 years (mean 40.5 years). Considering their locations; 12 were in the anterior fossa (50 %), 7 were in the tuberculum sella (29.1 %), and 5 were in both anatomic sites (20.8 %). Histopathologically, our series consisted of 15 meningiomas, 6 osteomas, 2 dermoid tumors and 1 metastatic carcinoma. We achieved gross total resection in 75 % of our patients. Ten patients presented with visual complaints and 7 of them improved postoperatively. Postoperative cerebrospinal fluid leakage (CSF) was observed in 3 patients and one of them developed meningitis and subsequently died of sepsis. CONCLUSION: Although the number of cases is low, EEEA seems like a safe, effective and well-tolerated treatment modality for anterior midline skull base lesions. But strict preventive measures should be taken for a possible CSF leak.

Expression of Sigma-Class Glutathione-S-Transferase in Fetal and Pediatric Filum Terminale Samples: A Comparative Study.

Background and objectives: The pathophysiology of tethered cord syndrome (TCS) in children is not well elucidated. An inelastic filum terminale (FT) is the main factor underlying the stretching of the spinal cord in TCS. Our study aimed to investigate the expression of glutathione-S-transferase (GST) in children and fetal FT samples in order to understand the relationship between this enzyme expression and the development of TCS. Materials and Methods: FT samples were obtained from ten children with TCS (Group 1) and histological and immunohistochemical examinations were performed. For comparison, FT samples from fifteen normal human fetuses (Group 2) were also analyzed using the same techniques. Statistical comparison was made using a Chi-square test. Results: Positive GST-sigma expression was detected in eight (80%) of 10 samples in Group 1. The positive GST-sigma expression was less frequent in nine (60%) of 15 samples from Group 2. No statistically significant difference was detected between the two groups (p = 0.197). Conclusions: Decreased FT elasticity in TCS may be associated with increased GST expression in FT. More prospective studies are needed to clarify the mechanism of the GST-TCS relationship in children.

The evaluation of the effects of steroid treatment on the tumor and peritumoral edema by DWI and MR spectroscopy in brain tumors.

OBJECTIVE: To investigate the effects of dexamethasone on brain tumor and peritumoral edema by different sequences of magnetic resonance imaging (MRI). MATERIALS AND METHODS: MRI was performed in 28 patients with brain tumor. Patients were divided into the 3 groups based on the histological diagnosis; Group I: high-grade glial tumor, Group II: low-grade glial tumor, and Group III: brain metastasis. The measurements of peritumoral edema volume and apparent diffusion coefficient (ADC) values were performed while the peak areas of cerebral metabolites were measured by spectroscopy in groups I and II. The changes in edema volumes, ADC values and cholin/creatine peak areas were compared. RESULTS: The volume of peritumoral edema was decreased in groups I and II, but increased in group III after dexamethasone treatment. These changes were not statistically significant for 3 groups. ADC value was decreased in group I and increased in groups II and III. Changes in ADC values were statistically significant. Cholin/creatine peak areas were decreased after dexamethasone in groups I and II, but these changes were also not significant. CONCLUSION: Dexamethasone has no significant effect on the volume of peritumoral edema in glial tumor and metastasis. Moreover, dexamethasone increases the fluid movements in low grade gliomas and metastases, decreases in high grade gliomas. However, more comprehensive clinical studies are needed to show the effects of dexamethasone on brain tumors and peritumoral edema.

A Comparison Between the Effectiveness of Full Outline of Unresponsiveness and Glasgow Coma Score at Neurosurgical Intensive Care Unit Patients.

AIM: To evaluate the effectiveness and the use of Glasgow Coma Score (GCS) and Full Outline of Unresponsiveness (FOUR) score by nurses in the follow-up and evaluation of patients admitted to the neurosurgical intensive care unit for cranial surgery or head trauma. MATERIAL and METHODS: The study was performed at a neurosurgical intensive care unit. Sample size was determined as 47 patients (a= 0.05, power= 0.95). The correlation coefficient less than 0.5 was accepted as weak. In the first 24 hours, Karnofsky Performance Scale was applied and the Acute Physiology and Chronic Health Evaluation II (APACHE II) Score calculated for patients who were admitted to the intensive care unit for cranial surgery or head trauma. Also FOUR and GCS were applied by two different nurses twice a day. Intraclass Correlation Coefficient, Pearson Correlation and Cronbach?s Alpha Security Index analyses were used to evaluate the data. RESULTS: Concordance was above 0.810 and correlation was above 0.837 between GCS and FOUR score evaluation results of nurses. Correlation of two different evaluation at every shift for GCS was 0.887, and for FOUR was 0.827 and above. Karnofsky Performance Scale correlation with FOUR and GCS scores of patients at admission and discharge from the intensive care unit was 0.709 and above. The correlation between APACHE II and FOUR was 0.851; between APACHE II and GCS 0.853. There was no difference between the evaluations of two scores and two nurses statistically. CONCLUSION: Concordance between nurses was found high both for GCS and FOUR. The FOUR score is as effective as GCS on the follow-up of patients who are managed in the neurosurgical intensive care units.

Comparison of Electrophysiological Outcomes of Tethered Cord Syndrome and Spinal Intradural Tumors: A Retrospective Clinical Study.

AIM: Electrophysiological evaluation of the outcomes of spinal procedures is important for neurosurgeons. Somatosensorial evoked potentials (SSEPs) are used for electrophysiological evaluation of tethered cord syndrome (TCS) and spinal intradural tumors (SIT). The aim of this study was to document the electrophysiological outcomes of surgery for TCS and SIT and to compare the results based on the preoperative diagnosis. MATERIAL AND METHODS: The data of 30 patients, who were operated for TCS and SIT between 2011 and 2013, were reviewed retrospectively. Surgical release of the spinal cord was performed for TCS and tumor removal was performed for SIT. Median and tibial nerve SSEPs at the left and right sides were measured at preoperative, early and late postoperative periods and compared statistically based on the diagnosis and the time of electrophysiological assessment. RESULTS: The diagnosis was TCS in 12 (40%) patients and SIT in 18 (60%) patients. There was a significant difference between preoperative, and early and late postoperative SSEPs values. Tibial nerve latencies were prolonged in the early postoperative, but shortened in the late postoperative period. In contrast, median nerve latencies were shortened in the early postoperative, but prolonged in the late postoperative period. There was no significant difference between the TCS and SIT groups based on the surgical intervention. CONCLUSION: Tibial nerve latency may be prolonged in the early postoperative period of TCS and SIT patients. However, electrophysiological changes were not predictive for these patients. Further studies with more patients are needed for other spinal lesions.

Fully Endoscopic Resection of Intra-Axial Brain Lesions Using Neuronavigated Pediatric Anoscope.

AIM: To present a new simple disposable tubular retractor which provides fully endoscopic resections of the intraaxial brain lesions. MATERIAL AND METHODS: A total of 13 patients underwent surgical resection of an intraaxial brain lesion larger than 3 cm with a fully endoscopic approach using the navigation-guided pediatric anoscope. The anoscope was adapted to serve as a tubular retractor. All lesions were resected under endoscopic visualization and navigation guidance. There were 7 men and 6 women with a mean age of 49.6 years (range, 19-76 years). Lesion location was as follows: frontal (n=4), parietal (n=1), frontoparietal (n=2), temporal (n=2), and intraventricular (n=4). RESULTS: With the use of this technique, preoperative goals of surgery were met in all patients. Gross total resection of the lesions was achieved in 7 of 13 patients (53.8%), near-total resection in 3 patients (23.1%) and subtotal resection in 3 (23.1%) patients. The histological diagnosis included 2 metastases, 5 (38.5%) glioblastomas, 3 meningiomas, 2 low grade gliomas and one oligodendroglioma. There were no complications related to the surgical procedure. Duration of surgery ranged from 60 to 110 minutes, with an average 90 minutes. The average postoperative hospital stay was 2.7 days. CONCLUSION: Endoscopic resection of deep-seated brain lesions with the neuronavigated tubular retractor is a safe and an effective technique and may be a feasible alternative to conventional microsurgical or endoscope-assisted methods in selected patients. The modified transparent plastic pediatric anoscope can be used as a tubular retractor and it is easy to apply, simple, lightweight, inexpensive and effective.

The Use of Neuronavigation and Intraoperative Imaging in Spinal Stabilization Surgery.

AIM: Misplacement of pedicle screw is the serious complication of spinal surgeries. Intraoperative imaging techniques and navigation systems are currently in use for the prevention of this complication. The aim of this study was to document the results of our experience with the navigation and intraoperative imaging technique and to share our experience with our colleagues. MATERIAL AND METHODS: Between 2011 and 2014, one hundred and two patients underwent instrumented spinal surgery while using intraoperative computed tomography (iCT) and a navigation system. All patients had a CT scan performed no more than three days postoperatively to confirm adequate placement of the screws. The accuracy of pedicle screw placement was assessed by postoperative CT scan. Pedicle violations were graded according to an established classification system. RESULTS: In the 36-month period, a total of 610 screws in 102 patients were evaluated. Stabilization surgery was performed in the lumbosacral region in 51 (50%) patients, lumbar region in 35 (34.31%) patients, cervical region in 5 (4.9%) patients, thoracolumbar region in 7 (6.86%) patients and thoracic region in 4 (3.92%) patients. Of the 610 screws, 396 (64.91%) were placed in lumbar, 66 (10.81%) in thoracic, 106 (17.37%) in sacral and 42 (6.8%) in cervical vertebrae. Of the 610 screws, 599 screws (98.18%) were placed without a breach. Grade 1 breaches occurred in 8 screws (1.31%), Grade 2 breaches occurred in 2 screws (0.32%), and Grade 3 breaches in 1 screw (0.16%). No dural defect or neurological deficit occurred after the surgeries. CONCLUSION: The use of an iCT scan associated with a navigation system increases the accuracy of pedicle screw placement. This system protects the surgical team from fluoroscopic radiation exposure and the patient from the complications of screw misplacement and repeated surgeries.

Evaluation and Management of Lumbosacral Myelomeningoceles in Children.

OBJECTIVE: Myelomeningoceles are the common form of open neural tube defects that are usually associated with neurological deficits. Many techniques of repair and methods of prevention have been proposed with respect to the size of defect and the neurological condition of patient. The aim of this study was to report our experience on the management of lumbosacral myelomeningoceles in children. MATERIALS AND METHODS: We retrospectively analysed the data of 36 paediatric cases of surgically lumbosacral myelomeningocele treated in our department between 1998 and 2013. Twenty (56%) patients were female and sixteen were male, with a mean age of 4 months (ranged between 0 and 24 months). All patients had neurological deficits in the preoperative period. Computed tomography was performed in 33 (92%) patients and magnetic resonance imaging in 15 (42%) patients in the preoperative period. Repair of the myelomeningocele and closure of the skin defect were performed in all patients. The mean follow-up period was 36 months. RESULTS: Thirty (83%) patients were operated for hydrocephalus and 10 (28%) patients were re-operated for tethered cord syndrome during the follow-up period. Neurological worsening was not observed in any patient while cerebrospinal fluid fistula was detected in 2 patients. CONCLUSION: Surgical treatment using appropriate microsurgical techniques is crucial for lumbosacral myelomeningoceles in children. Early surgical intervention with close follow-up will improve the neurological condition of the patients.

Pain perception differences between patients and physicians: a pain severity study in patients with low back pain.

AIM: Perception, definition and tolerance of pain vary individually because of its subjective character. This study aimed to determine the perception differences between patients with mechanical low back pain (MLBP) and their physicians regarding the assessments of the patients' pain severity. MATERIAL AND METHODS: 181 patients with MLBP and 2 physicians took part in the study. Before the initial examination, the patients filled out a questionnaire consisting of demographic data, pain characteristics, Modified Oswestry Disability Questionnaire (MODQ) and Visual Analog Scale (VAS). The patients' forms were concealed from the physicians. Then physicians examined their patients and rated their pain severity using a different VAS form. RESULTS: The mean age of the patients was 36.2 ± 12.3 years. 64.6% (n:117) were female, 71.9% (n:13) were highly educated and 57.1% (n:103) were obese. Physicians always rated the patients' pain severity significantly lower than the patients rated their own pain regardless of all demographic data (p < 0.001). Correlation between the VAS scores of patients and physicians were detected as 0.41 (p < 0.001) and the power of the study was calculated as 91.5%. The mean MODQ score of the patients was calculated as 54.4 ± 21.1. Reliability of the questions in MODQ was calculated as alpha:0.87. A moderate correlation between VAS ratings and MODQ was observed (r:0.52, p < 0.001). CONCLUSION: As a main factor directly affecting many outcomes, good communication between patient and physician, is essential to assess the patients' pain more accurately.

Computer-based surgical planning and custom-made titanium implants for cranial fibrous dysplasia.

BACKGROUND: The procedure of reconstruction after the removal of cranial fibrous dysplasia (FD) must be precise to achieve good functional and aesthetic results. Intraoperative modeling of implants is difficult and may cause cosmetic disturbances. OBJECTIVE: To present our experience with the treatment of cranial FD using preoperative computer-based surgical planning of tumor removal with reconstruction of the cranium with custom-made titanium implants. METHODS: Four patients underwent surgical treatment for cranial FD over a 2-year period. All patients were male with a mean age of 25.25 years and had monostotic-type FD. Computed tomography (CT) with 0.5-mm slices was obtained preoperatively. Computer-based planning of the tumor removal was performed, and a template was created by the computer to determine the margins of tumor removal. After this procedure, the preoperative computer-based construction of the titanium implant was performed. The patients underwent surgical treatment, and the tumor was removed with the use of this template. Then, the titanium implant was inserted onto the bone defect and fixed with mini-screws. Patients were followed up by periodic CT scans. RESULTS: The histological diagnosis of all patients was FD. No intraoperative or postoperative complications have occurred. Postoperative CT scans showed complete tumor removal and confirmed appropriate cosmetic reconstruction. The mean follow-up period was 15.25 months. CONCLUSION: Computer-based surgical planning associated with the production of custom-made titanium implants is a highly promising method for the treatment of cranial FD. Better radiological and cosmetic outcomes could be obtained by this technique with interdisciplinary work with medical designers.

Histological structure of the medial and lateral walls of cavernous sinus in human fetuses.

PURPOSE: The aim of this study is to elucidate the architecture of these fine structures in human fetuses. METHODS: The histological examination of medial wall (MW) and lateral wall (LW) was performed in 15 normal human fetuses. Eleven fetuses were female and four were male. The gestational age ranged between 14 and 35 weeks. The weight ranged between 180 and 1750 g. The wall samples (two MW and two LW from each fetus) were obtained by microsurgical technique and underwent histological examination. Each wall was examined for the structure and composition of collagen and elastic fibers, ganglions, peripheral nerves, and vessels. RESULTS: A total of 60 wall samples (30 MW and 30 LW) were examined in 15 fetuses. Loose connective tissue composed of type III collagen was observed in both of the walls. Elastic fibers were observed only in three wall samples (two MW and one LW). Ganglion was detected in 11 samples (nine in LW and two in MW), and peripheral nerve was found in 28 walls (18 LW and 10 MW). Vessels were observed in 51 samples (26 LW and 25 MW). None of the walls was stained with type I collagen. CONCLUSIONS: The structure of LW and MW of the cavernous sinus (CS) in fetuses is mainly composed of collagen tissue while some elastic fibers are supported by this tissue. Type III collagen is the main component of fetal CS walls. Because of the weak histological structure, CS may be more prone to tumor invasion in infants.

Surgical strategies for the removal of sphenoorbital meningiomas.

AIM: Surgical removal of sphenoorbital meningiomas is challenging for neurosurgeons. The aim of study is to share our experience on sphenoorbital meningiomas and to provide a picture of the current state of the art in surgical treatment of these tumors. MATERIAL AND METHODS: The data of 13 cases of sphenoorbital meningioma who were operated between 2006 and 2013 was reviewed retrospectively. Intraorbital extension was present in 10 cases while sphenoid bone invasion was detected in 9 cases. All patients underwent surgical treatment after the radiological evaluation with magnetic resonance imaging and computed tomography. The degree of resection and the clinical outcome of all patients were analyzed. RESULTS: Extended pterional approach with a large frontotemporal craniotomy was performed in all cases. Simpson's grade I and II excision was achieved in 4 (31%) cases while subtotal excision (Simpson's grade III or higher) was performed in 9 cases. The main reason for subtotal excision was the cavernous sinus invasion. Optic canal decompression was performed in patients with intraorbital invasion. CONCLUSION: Although total removal is the main objective of surgery, the sphenoorbital meningiomas are difficult to resect especially with cavernous sinus invasion. But in the meantime, it is not recommended to take any excessive risks to achieve a greater degree of resection for a benign tumor. Endoscopic approach is an option for inferomedial orbital parts of these tumors.

The use of neuronavigation and intraoperative imaging systems in the surgical treatment of orbital tumors.

AIM: We aimed to show the effects of neuronavigation and intraoperative imaging systems on the surgical outcomes of orbital tumors. MATERIAL AND METHODS: Seventeen patients who underwent surgical treatment for orbital tumors by transcranial and transnasal approaches between 2008 and 2013 were analyzed retrospectively. Twelve of them were male and 5 were female. The mean age was 41.6 years. Neuronavigation systems were used in all cases. Four patients were operated using intraoperative imaging systems. RESULTS: The transcranial approach was used in 9 (53%) patients, endoscopic medial orbital approach in 4 (23.5%), endoscopic inferolateral approach in 1 (6%), cranioorbitozygomatic approach in 1, lateral approach in 1, and the combined (medial endoscopic and lateral) approach in 1 patients. Total resection was achieved in 5 patients, gross total excision in 2, subtotal in 9 and partial in 1 patients. CONCLUSION: Modern technology has made a significant contribution to the treatment of orbital tumors. Although technological equipments facilitate the excision of tumors, the level of resection is mainly determined by the nature of tumor and adhesion to the adjacent neurovascular structures. It should not be forgotten that advanced technology never replaces a good anatomical knowledge and surgical experience, but has a complementary role.

Histological structure of filum terminale in human fetuses.

OBJECT: The structure of the filum terminale (FT) is important in the development of tethered cord syndrome (TCS) in children. Although many studies have been performed on the histological structure of the FT in adults, there has been no detailed investigation for those of fetuses. The aim of this study was to examine the histological structure of the FT in normal human fetuses and to compare the results with those of previous studies. METHODS: The histological examination of the FT was performed in 15 normal human fetuses; 11 of them were female and 4 were male. The gestational age of the fetuses ranged between 14 weeks and 35 weeks, and they weighed between 180 g and 1750 g. The FT of each fetus was cut and examined for adipose tissue, fibrous tissue, peripheral nerve, ganglion, ependymal cells, gliosis, elastic fibers, and collagen types (Types I and III). RESULTS: Adipose tissue was observed in 2 specimens (13%), whereas fibrous tissue was found in 8 specimens. Peripheral nerve was detected in 11 (73%), ganglion in 6, ependymal cells in 5, and glial tissue in 7 FT samples. Type III collagen was present in 12 specimens (80%) with different concentrations, whereas Type I collagen and elastic fibers were not detected. CONCLUSIONS: The normal structure of the FT in fetuses is different from its structure in adults. The FT has no elasticity during intrauterine life because of the lack of elastic fibers. More detailed studies are needed to understand the histological basis of TCS in children.