Skull Base Research Articles

Evaluation of the Effect of Pre-bent Z-shaped Titanium Plate on Narrowing of Zygomatic Arch in L-shaped Reduction Malarplasty

Objective: Pre-bent titanium plates are widely used for internal fixation in L-shaped zygomatic reduction. The aim is to evaluate the effect of pre-bent Z-shaped titanium plate on the narrowing of the zygomatic arch in L-shaped reduction malarplasty. Methods: Thirty cosmetic female patients were selected and scanned using computed tomography (CT). The CT images of pre-operation (T1) and post-operation(T2) were re-established through MIMICS26.0 (Materialise). After the 2 images were registered based on the skull base, the narrowing distance (ZRN) at the posterior end of the free zygomatic arch, as well as the preoperative and postoperative cross-sectional dimensions of the zygomatic arch, were measured. The ZRN and the altitude of the pre-bent titanium plate (TA) were compared using an independent t test, and their correlation was also analyzed using the Pearson coefficient. The preoperative and postoperative longest diameter (L1) and shortest diameter (L2) of the posterior zygomatic arch were compared using a paired t test. Results: The TA was 3.80±0.82 mm and the ZRN was 3.21±0.82 mm. The difference value was 0.59±0.41 mm, which was statistically significant. TA showed a strong correlation with ZRN (r=0.916, P=0.002). The L1 and L2 of the zygomatic arch root were slightly reduced postoperatively. Conclusion: The pre-bent Z-shaped titanium plate does not completely correspond to the zygomatic arch narrowing distance in the actual application of L-shaped reduction malarplasty. However, it can control the narrowing distance of the zygomatic arch predictably, and achieve satisfactory surgical outcomes.

Semi-Automated Virtual Endoscopy of the Frontal Recess.

Virtual endoscopy (VE) is the computer-based reprocessing of diagnostic imaging to simulate endoscopy of an anatomic region of interest. VE of the Frontal Sinus Outflow Tract (FSOT) may assist surgical planning and education. VE was performed on 16 normal sinus computed tomography (CT) scans for a total of 32 sides using the "path-to-target" tool on the TruDi surgical navigation system (ver. 2.3; Acclarent, Irving, CA, USA). To aid orientation during VE, planning points were placed on the middle turbinate, ethmoidal bulla, and skull base. The VE representation of anatomy and FSOT accuracy was manually confirmed by reviewing the corresponding orthogonal CT images and comparing them to the computed pathway. Of the 32 sides, the software successfully calculated the FSOT in 22 sides (69%). Of those 22 sides, the calculated FSOT, depicted in the VE sequences accurately represented the FSOT. Among sides with an accurately calculated FSOT, the VE sequences depicted a "fly-through" from a starting point in the middle meatus around various frontal recess cells to the end point in the frontal sinus. This pilot study demonstrates that software-generated VE of the FSOT is indeed feasible but requires confirmation by the surgeon for accuracy. Instances in which the software did not achieve its objective may drive further refinements of the protocol. VE of the FSOT should be explored as a tool for preoperative planning and surgical education.

Presentation and Optimal Management of Anterior and Central Skull Base Osteoradionecrosis: Systematic Review and Meta-Analysis.

To conduct a systematic review and meta-analysis to compare the efficacy of conservative treatment versus surgical debridement versus debridement followed by vascularized tissue coverage to provide evidence-based guidance on the management of osteoradionecrosis of the anterior and central skull base. PubMed, Embase, and Cochrane Library. Systematic review and data sources including PubMed, Embase, and Cochrane Library were accessed using PRISMA guidelines. Meta-analysis was performed on treatment type and resolution of osteoradionecrosis. A total of 13 articles met the inclusion criteria. Patients were categorized into conservative medical treatment versus surgical treatment. Conservative treatment included patients undergoing hyperbaric oxygen therapy, antibiotics, pentoxifylline-tocopherol-clodronate, or a combination of the three. Eight out of 197 patients treated with conservative therapy had resolution of symptoms (4.1%) while 135 of 188 patients treated with surgical intervention had resolution of symptoms (71.8%). Of these, 104 patients (91.2%) in the vascularized tissue group experienced resolution of symptoms. Surgery was superior to medical treatment alone in the resolution of skull base osteoradionecrosis. Vascularized surgical treatment fared significantly better when compared with both surgical debridement only and/or medical treatment. Our findings suggest that surgical treatment should be considered earlier in patients with skull base osteoradionecrosis to prevent severe or fatal sequelae. NA Laryngoscope, 2024.

Chronic hearing loss turns out being a calcified chondroid mesenchymal neoplasm with FN1::FGFR2 fusion.

A 53 year old female presented with a six-year history of right-sided slow deterioration in hearing and a feeling of pressure in the right ear. The patient had not experienced any pain but reported some paresthesia of the right half of the tongue, whereas no further other cranial nerve deficits were evident. The otoscopy was unremarkable as well as the rest of the clinical ENT examination except for a slight asymptomatic swelling of the right cheek. Imaging findings showed an expansive tumor infiltrating and destroying the right lateral skull base. The tumor was partially composed of cystic/regressive lesions with high contrast media uptake. The tumor had high-signal intensity with water-sensitive sequences (T2w) and was hypointense on T1w images. We performed a tumor resection via a transparotideal-infratemporal approach. Histologically, the tumor was composed of granular variably calcified chondroid matrix with extensive regressive changes and granulation-like tissue reaction associated with calcinosis and crystal deposition. Molecular analysis of the tumor via the TruSight- RNA-Fusion panel detected a fusion involving FN1::FGFR2, consistent with "calcified chondroid mesenchymal neoplasm" (CCMN), a rare tumor entity recently defined by Liu et al 2021. In regular follow-up care no residual tumor has been detected in imaging studies (MRI and CT) within 2 years and 4 months. The biology and consequently the radio sensitivity cannot be defined precisely since long term results are missing due to the first description of this entity in 2021. As a consequence, surgical resection is recommended as the treatment of choice. Thorough clinical and radiological follow-up is mandatory as local recurrences are to be expected due to the infiltrative behavior. In case of a loco regional recurrence the fusion with FGFR2 may represent a therapeutic option for a targeted therapy on molecular level.

MENINGIOMA SIZE IS POSITIVELY CORRELATED WITH TUMOR WHO GRADE

Abstract AIMS It is well established that the surgical outcome is poorer in larger meningiomas. Vascular/ neural encasement and bone/dural/vascular invasion complicate surgical resection. Nevertheless, it is also likely that meningiomas will become biologically more aggressive with increasing size and tumor cell burden. To prove this hypothesis we studied radiological features of 316 meningiomas and correlated these features with tumor WHO-grade. METHOD 316 meningioma patients who were operated on and who received pathological diagnoses at one single institution were analyzed. Pathological grading was revised by one single neuropathologist according to WHO 2021 criteria. 123 high-grade (WHO grade 2 and 3) patients were initially selected and later substituted with a further 193 age and anatomical-location-matched individuals. Preoperative MRI studies were analyzed for size, hyperostosis, intratumoral calcification, mass effect, peritumoral edema, shape (globular/en-plaque), lobulation, cystic component, intratumoral heterogeneity, dural tail, and necrosis/hemorrhage. Univariate analysis as well as logistic regression were performed. RESULTS High-grade meningiomas were significantly more common to have lobulation (p: 7.111 x 10-8), necrosis/hemorrhage (p: 1.176 x 10-6), peritumoral edema (p: 3.421 x 10-6), intratumoral heterogeneity (p: 1.201 x 10-5), mass effect (p: 0.0002408), and cystic component (p: 0.003519) compared to WHO grade 1 meningiomas. Logistic regression indicated that tumor volume was an independent and significant parameter. High-grade tumors were significantly larger (40.83 cm3 vs 22.18 cm3, p: 3.518 x 10-6). Skull base meningiomas were of significantly lower grade (p: 0.001318). Mean volume was significantly higher in high-grade meningiomas. Mean tumor volume varied significantly among histopathological subtypes but was highest in anaplastic and atypical subtypes. Tumor volume was strongly correlated with mitosis (p: 2.353 x 10-6), hypercellularity (p: 1.22 x 10-4), spontaneous necrosis (p: 3.273 x 10-4), brain invasion (p: 0.02491), macronucleus (p: 0.05327), small cell (p: 0.09425), and ki-67 levels (p: 2x10-16). CONCLUSION Tumor size is strongly correlated with WHO grade in meningiomas.

Factors influencing osteoradionecrosis progression during hyperbaric oxygen therapy: A case study

Introduction Although relatively uncommon, osteoradionecrosis (ORN) remains a serious complication following radiotherapy. Various therapeutic approaches, including hyperbaric oxygen therapy (HBOT), are utilized in managing ORN. This study aims to evaluate the role of HBOT in ORN management and to identify predictive factors influencing the evolution of head and neck ORN after HBOT. Methods This retrospective study includes 46 patients who received HBOT for head and neck ORN between 2017 and 2020. The patients were divided into two groups: Group 1 (n=36) included those with regression or stabilization of ORN, while Group 2 (n=10) comprised patients with worsening lesions. We performed a statistical study in order to identify factors influencing ORN progression under treatment. Results ORN affected the mandible in 93.5% of patients, the maxilla in 2 cases, and the skull base in 4 cases. All patients received HBOT, with an average of 44.65 sessions. Pre-operative HBOT was administered in 17% of cases, and post-operative HBOT was given in 42% of cases. After at least 20 sessions, ORN regressed in 33% of cases, stabilized in 45%, and worsened in 22%. Analysis of factors influencing ORN progression on the univariate study revealed significant associations with high blood pressure (p=0.046), larger tumor size (p=0.004), advanced tumor stages (p=0.048), mean radiation dose (p=0.002), delays between dental care and radiotherapy (p=0.045), and the location of ORN within the mandible (p=0.049). Additionally, the number of HBOT sessions significantly affected ORN evolution, with more sessions correlating with better outcomes (p=0.001). In the multivariate analysis, variables such as the average interval between dental care and radiotherapy (p=0.043) as well as the number of HBOT sessions (p=0.040) emerged as significant influencers of ORN evolution. Conclusion Our study provides valuable insights into the management of ORN by identifying key predictors that influence the post-therapeutic evolution of head and neck ORN after HBOT.

Front Cover

Front Cover: The cover image is based on the article Skull base surgery for malignant tumors: The 2nd international collaborative study (1995–2015) by Jatin P. Shah MD et al., https://doi.org/10.1002/hed.27746.image

The role of endoscopic endonasal surgery in the management of sinonasal malignant tumors with skull base involvement

Sinonasal malignant tumors (SNMTs) represent a rare and heterogeneous group of tumors. SNMTs often present late which can lead to complex, patient-specific treatment decisions. Over the last two decades, endoscopic endonasal surgery (EES) has become a more frequently utilized surgical approach to removing these tumors. Increasingly, studies have compared the outcomes of this approach to traditional open approaches for different SNMTs. Differences in histology and extent of invasion impact the utility of EES. Negative margins are critical for improving survival; however, skull base involvement can add anatomical challenges for achieving negative margins during EES. This paper reviews the literature on outcomes of EES for SNMTs with skull base involvement and presents evidence supporting the utility of EES for select patients. EES is a safe and effective treatment in patients with less invasive SNMTs or less aggressive histology and can provide patients with fewer complications and morbidity than traditional open approaches. As such, it plays a key role in surgical management, providing either sole access or a critical avenue for SNMT removal. EES plays a key role in the multimodal oncological approach to the treatment of different SNMT histologies.

Morphological and Morphometric Analysis of Carotid Canal Apertures in the Nigerian Population

Background: The external opening of the carotid canal (EOCC), the entry point of the internal carotid artery into the skull, varies across populations. This study characterized the EOCC with the mastoid process (shortest distance from the EOCC to the tip of the mastoid process [SDTCC]), the foramen magnum (shortest distance from the EOCC to the foramen magnum [SDFM]), and the midline of the skull base (shortest distance from the EOCC to the midline of the base of the skull [SDMCC]) in the Nigerian population. Materials and Methods: Fifty skull base pictures were taken in the plumed position with a digital camera. Measurements were taken using Image J software, and Euclidean distances were calculated. The shapes of the EOCC were noted. Paleontological Statistics (PAST 3.0) was used to perform descriptive statistics. Paired ttest and Pearson correlation were used to compare bilateral values and the relationship between the parameters, respectively. Results: The length (right, 0.53 [standard deviation (SD)=2.5] mm; left, 10.99 [SD=2.84] mm) and width (right, 13.96 [SD=2.43] mm; left, 14.16 [SD=2.09] mm) of the EOCC were recorded. In contrast to the populations in South Africa, Serbia, and India, the length of the EOCC obtained from this study is shorter than the breadth. The length of SDFM (right, 41.04 mm; left, 44.13 mm), SDMCC (right, 58.4 mm; left, 57.97 mm), and SDTCC (right, 57.29 mm; left, 55.61 mm) was established among Nigerians. Conclusion: The Nigerian population showed EOCC of shorter length than the breadth compared to other populations, and the size of the skull is independent of the foramina size. These dimensions may provide information for procedures that affect the skull base.

Circumferential exposure of the cavernous sinus and parasellar region through a combined open and endoscopic endonasal transcavernous approach, a morphometric study.

Although recent trends currently favor the endoscopic endonasal transcavernous approach (EETA) over the pretemporal transcavernous approach (PTA) for certain cavernous sinus pathologies, dedicated assessment of the surgical exposure and maneuverability is wanting. Toward this aim, this morphometric study quantifies these variables within four cavernous sinus compartments by comparing the PTA, EETA, and a combined approach to achieve a circumferential dissection (EETA-PTA). In five latex-injected specimens, exposure volumes of the EETA, PTA, and circumferential EETA-PTA approaches were quantified; the latter combined the most conservative options of both the endoscopic and open approaches. Two clinical cases illustrate the combined approach. EETA-PTA provided the largest volume of exposure (65.6% vs 35% PTA vs 44.6% EETA, P = 0.01) and eliminated the need to mobilize the ICA or cross cranial nerves. Although EETA and PTA approaches afforded comparable exposure volumes along the entire cavernous sinus (34.9 vs 44.6%), the EETA better exposed medial and inferior compartments (whereas the PTA exposed larger volumes in the lateral and superior compartments. The combined EETA-PTA yielded 66% of total cavernous sinus exposure volumes and eliminated the need to mobilize the ICA or cross cranial nerves. Our methodology aligns with strategies that use a modular concept to divide the skull base into compartments for maximal safe resection. Excluding soft tumors, the EETA is preferred for medial and inferior lesions and the PTA for superior and lateral lesions. A staged combined EETA-PTA may safely yield a 360-degree access for extensive multi-compartment lesions that span neurovascular structures within the cavernous sinus.

Adaptive infrared patterns for microscopic surface reconstructions.

Multi-zoom microscopic surface reconstructions of operating sites, especially in ENT surgeries, would allow multimodal image fusion for determining the amount of resected tissue, for recognizing critical structures, and novel tools for intraoperative quality assurance. State-of-the-art three-dimensional model creation of the surgical scene is challenged by the surgical environment, illumination, and the homogeneous structures of skin, muscle, bones, etc., that lack invariant features for stereo reconstruction. An adaptive near-infrared pattern projector illuminates the surgical scene with optimized patterns to yield accurate dense multi-zoom stereoscopic surface reconstructions. The approach does not impact the clinical workflow. The new method is compared to state-of-the-art approaches and is validated by determining its reconstruction errors relative to a high-resolution 3D-reconstruction of CT data. 200 surface reconstructions were generated for 5 zoom levels with 10 reconstructions for each object illumination method (standard operating room light, microscope light, random pattern and adaptive NIR pattern). For the adaptive pattern, the surface reconstruction errors ranged from 0.5 to 0.7 mm, as compared to 1-1.9 mm for the other approaches. The local reconstruction differences are visualized in heat maps. Adaptive near-infrared (NIR) pattern projection in microscopic surgery allows dense and accurate microscopic surface reconstructions for variable zoom levels of small and homogeneous surfaces. This could potentially aid in microscopic interventions at the lateral skull base and potentially open up new possibilities for combining quantitative intraoperative surface reconstructions with preoperative radiologic imagery.

Deep learning model using planar whole-body bone scintigraphy for diagnosis of skull base invasion in patients with nasopharyngeal carcinoma

PurposeThis study assesses the reliability of deep learning models based on planar whole-body bone scintigraphy for diagnosing Skull base invasion (SBI) in nasopharyngeal carcinoma (NPC) patients.MethodsIn this multicenter study, a deep learning model was developed using data from one center with a 7:3 allocation to training and internal test sets, to diagnose SBI in patients newly diagnosed with NPC using planar whole-body bone scintigraphy. Patients were diagnosed based on a composite reference standard incorporating radiologic and follow-up data. Ten different convolutional neural network (CNN) models were applied to both whole-image and partial-image input modes to determine the optimal model for each analysis. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), calibration, decision curve analysis (DCA), and compared with expert assessments by two nuclear medicine physicians.ResultsThe best-performing model using partial-body input achieved AUCs of 0.80 (95% CI: 0.73, 0.86) in the internal test set, 0.84 (95% CI: 0.77, 0.91) in the external cohort, and 0.78 (95% CI: 0.73, 0.83) in the treatment test cohort. Calibration curves and DCA confirmed the models’ excellent discrimination, calibration, and potential clinical utility across internal and external datasets. The AUCs of both nuclear medicine physicians were lower than those of the best-performing deep learning model in external test set (AUC: 0.75 vs. 0.77 vs. 0.84).ConclusionDeep learning models utilizing partial-body input from planar whole-body bone scintigraphy demonstrate high discriminatory power for diagnosing SBI in NPC patients, surpassing experienced nuclear medicine physicians.

Growth Dynamic of the Dorsum Sellae in Fetuses

Objective: To determine the dimension of the dorsum sellae (DS) in fetuses. Methods: Skull bases of 32 fetuses aged from 17 to 32 weeks were included in the work. The length of the DS at its superior border (DSL-SB) and the thickness of DS at its middle part (DST-ML) were measured. In addition, DS’s height at its right lateral margin (DSH-RLB), at its left lateral margin (DSH-LLB), and at its middle part (DSH-ML) were measured. Results: DSL-SB, DSH-RLB, DSH-LLB, DSH-ML, and DST-ML were measured as 8.42±1.89, 2.67±0.68, 2.73±0.68, 2.48±0.75, and 2.00±0.50 mm, respectively. All parameters were statistically similar for both sexes (P>0.05). All parameters increased with advancing gestational weeks (P<0.001). Linear functions were calculated for DSL-SB (y=− 1.756 + 0.426 × age), DSH-RLB (y=− 1.072 + 0.156 × age), DSH-LLB (y=− 0.851 + 0.150 × age), DSH-ML (y=− 1.687 + 0.174 × age), and DST-ML (y=− 0.473 + 0.103 × age). Conclusion: In fetuses, DS size grows with age. The linear functions regarding DS-related parameters may be used to estimate its size.

Radiomic Applications in Skull Base Pathology: A Systematic Review of Potential Clinical Uses

Objectives Radiomics involves the extraction and analysis of numerous quantitative features of medical imaging which can add more information from radiological images often beyond initial comprehension of a clinician. Unlike deep learning, radiomics allows some understanding of identified quantitative features for clinical prediction. We sought to explore the current state of radiomics applications in the skull base literature. Methods A systematic review of studies evaluating radiomics in skull base was performed, including those with and without machine-learning approaches. Studies were summarized into thematic elements as well as specific pathologies. Results A total of 102 studies with 26,280 radiographic images were included. The earliest radiomic study was published in 2017 with exponential growth in research since then. Most studies focused on tumor diagnosis (40.8%), followed by tumor prognosis (31.1%), automated segmentation (16.5%), other applications (7.8%), and lastly prediction of intraoperative features (3.9%). Pituitary adenomas (41.7%) and vestibular schwannomas (18.4%) represented the most commonly evaluated pathologies; however, radiomics could be applied to a heterogeneous collection of skull base pathologies. The average study included 258677 cases (range 4; 6755). Conclusion Radiomics offers many functions in treating skull base pathology and will likely be an essential component of future clinical care. Larger sample sizes, validation of predictive models, and clinical application are needed. Further investigation into the strengths and weaknesses of radiomic applications in skull base treatments is warranted.

Evaluation of the Use of Intraoperative Neuronavigation in the Surgery of Brain Tumors: Single Center Experience and Retrospective Analysis of 172 Cases

Neuronavigation systems are computer-assisted procedures that use preoperative imaging data to ensure accurate anatomical orientation and safe resection during surgery. Despite their widespread use in neurosurgery, evidence of their effectiveness and reliability remains limited. This study aimed to examine the need for neuronavigation systems in patients with intracranial tumors, their relationship with tumor location and size, and their limitations. A retrospective analysis was conducted on 172 patients with intracranial tumors who underwent surgery using neuronavigation systems at our clinic between January 2021 and October 2023. Patients were classified based on tumor size into two groups: those with tumors <3 cm and those with tumors ≥ 3 cm. Further classification was done according to tumor locations such as supratentorial, infratentorial, and skull base, as well as based on superficial and deep-seated tumor locations. The need for neuronavigation systems was assessed using a scoring scale ranging from 0 to 2 assigned during surgery. Of the patients, 49.4% were male and 50.6% were female, with a mean age of 52.9 ± 16.2 years (range 2–80 years). The mean total score for neuronavigation system use was significantly higher in patients with tumors <3 cm and those with deep-seated tumors (p = 0.003). The need for neuronavigation was less in infratentorial tumors. Identifying anatomical and vascular structures during surgery was the surgical stage with the greatest need for neuronavigation use (n=172, 100%). Multivariate binary logistic regression analysis revealed that tumor size ≥3 cm and superficial location were risk factors determining the need for neuronavigation systems. İdentifying anatomical and vascular structures in supratentorial and deep-seated tumors, and evaluating surgical resection in tumors <3 cm are the areas where the use of neuronavigation systems is necessary.

Optimising surgical outcomes for skull base epidermoid cysts

Introduction. Surgery for skull base epidermoid cysts (SBECs) has several inherent risks including aseptic meningitis and cerebrospinal fluid (CSF) malabsorption. Perioperative measures to reduce the likelihood of such complications have not been evaluated, and this study sought to compare outcomes before and after implementation of an institutional perioperative protocol in the management of SBECs. Methods. Review of a prospective database of surgically managed SBECs. Outcomes were compared before (2003-2008) and after (2010-2021) implementation of a perioperative protocol including intraoperative hyper-irrigation, prolonged course of postoperative steroids and aggressive management of CSF malabsorption. Results. 39 patients were included: 12 before and 27 after implementation of the protocol. The groups were similar with respect to mean age (p = 0.99), gender (p=0.29), surgical approach – most commonly retrosigmoid (p>0.99) and extent of resection – most commonly total or near total (p=0.64). The post protocol implementation group had a significantly lower rate of CSF diversion (p = 0.04). The overall rates of hydrocephalus (7% vs. 30%), CSF leak (19% vs. 33%), bacterial meningitis (15% vs. 33%) and mean length of stay (12 days vs. 49 days) were lower in the post-implementation group, although differences did not reach statistical significance. Rates of aseptic meningitis and cranial nerve palsies were similar. Conclusions. Our additional perioperative measures resulted in more favourable CSF dynamics with reduced need for CSF diversion and secondary consequences such as wound leaks and infective meningitis.

Effectiveness of Preoperative Antiseptic Preparation in Transnasal Skull Base Surgery: A Randomized Three-Arm Controlled Trial

Objective: Transnasal skull-base surgery is a complex and invasive procedure that involves the use of preoperative antiseptic preparations. However, evidence supporting their use in preventing postoperative infectious complications is limited. The aim of this study is to assess the efficacy of preoperative antiseptic techniques in reducing postoperative infectious complications within 30 days of surgery. Methods: A multicenter, prospective, randomized, single-blind, three-arm trial was conducted from February 2019 to October 2021. Participants were randomized to either of three antiseptic preparation techniques: external 0.9%NaCl nasal preparation, external 0.05% chlorhexidine gluconate, or intranasal irrigation with 80 mg of gentamicin added to 1000 ml of 0.9%NaCl plus external nasal preparation with chlorhexidine gluconate 0.05%. A total of 130 adults with skull-base pathologies were randomized, 12 were excluded before randomization for failure to meet inclusion criteria (n=9) or refusal to participate (n=3). We excluded patients with evidence of infection adjacent to the surgical site, allergies to preparation methods, those who underwent craniotomy during the same admission, and pediatric patients. Results: The mean age of participants was 43.26±14.45 years. Nine patients developed postoperative infections (meningitis, n=8; sinusitis, n=2). Among the factors studied, length of surgery (p=0.002), perioperative CSF diversion (p=0.01), chordoma (p=0.004), extended approach (p=0.026), and postoperative CSF leak (p=0.025) were significantly associated with postoperative infections. There were no clinically meaningful or significant differences in the studied intervention groups regarding postoperative infectious complications. Conclusion: Preoperative antiseptic techniques failed to prefer one application to prevent postoperative infectious complications in patients who underwent endoscopic transnasal skull-base surgery.

Acalvaria, rare congenital malformation in palestine: case report and literature review

Introduction and Importance: Acalvaria is a rare congenital anomaly characterized by absent cranial vault bones, often misdiagnosed as anencephaly or encephalocele. Case Presentation: We present a case of a 10-day-old male neonate with Acalvaria, delivered normally at 37+5 weeks, with a birth weight of 2.7 kg and dysmorphic features including low-set ears and a sandal gap. Skull X-ray revealed absent parietal, temporal, and frontal bones. Initially admitted for potential sepsis, he has since shown normal development at three months, with ongoing conservative management. Clinical Discussion: Acalvaria is a rare congenital malformation marked by the absence of cranial vault bones, dura mater, and scalp muscles. Our case presents partial calvaria absence with normal skull base, classified as primary acalvaria. Associated anomalies necessitate thorough evaluation for prognosis. Diagnosis can occur as early as 12 weeks gestation via ultrasound, but management remains conservative, focusing on supportive care and monitoring for potential surgical interventions later. Conclusion: Acalvaria is a rare, fatal anomaly requiring conservative management; antenatal care and psychological preparation are essential for affected families.

Poorly differentiated chordoma: recognising this complex and rare aggressive tumour with characteristic immunohistochemical profile.

Poorly differentiated chordoma (PDC) is an uncommon subtype of chordoma, distinct in its occurrence in paediatric age group, location, variable epithelioid/rhabdoid/spindled histomorphology and the lack of physaliphorous cells (classical of chordoma) and immunohistochemistry (INI-1 loss, brachyury positive). We describe two cases of PDC. A3-year-old male and 4-year-old female child presented with neck stiffness and infiltrating tumour involving the skull base and upper cervical vertebral segments. Histopathology showed a tumour with sheets of cells having epithelioid to rhabdoid morphology and absence of physaliphorous cells. The tumour cells were positive for pan-cytokeratin, EMA, CD99 and vimentin and showed loss of INI-1 suggesting differentials of epithelioid sarcoma and atypical teratoid/rhabdoid tumour. On careful review of the clinical, radiological and pathological features, the additional immunohistochemistry for brachyury was performed, and its positivity clinched the diagnosis of PDC. Both the patients succumbed within a short span post-surgery. The present case study helps in creating an awareness and attempts to expand our knowledge in relation to the spectrum of chordoma (clinico-histological) and its immunohistochemical profile.

Spring-Assisted Cranioplasty in Unicoronal Synostosis: Analysis of Outcomes

Background: Spring-assisted cranioplasty and successful long-term outcomes for sagittal synostosis has been well described in recent literature. However, there is a paucity of data regarding the application of springs to unicoronal synostosis. Unicoronal synostosis (UCS) presents unique challenges in its causation of skull base scoliosis and orbital asymmetry. Many surgeons feel that the fronto-orbital advancement and vault remodeling is the most effective and reliable strategy to counteract these changes. Here we present our experience and outcomes with spring cranioplasty for unicoronal synostosis. Materials and methods: A retrospective review of non-syndromic unicoronal synostosis patients undergoing spring-assisted cranioplasty was performed. Preoperative and postoperative intracranial volume (ICV), orbital volume (OV), orbital height (OH), orbital width (OW), midface twist (MFT), and skull-base twist (SBT) were measured from DICOM CT data. Analysis was performed with Materialize software (Leuven, Belgium). Paired t-tests were performed using Excel. Results: Ten patients (5 females, 5 males) had springs placed at 100.1 days (avg). Average ICV: preop: 608.2 ± 101.4 cc, postop: 995.2 ± 166.1 cc. Differences in orbital volume and height in the preop affected orbit versus non-affected orbit was significant ( P = .01, P ≤ .001 respectively) whereas no significant difference between the two sides postoperatively was observed ( P = .19, P = .58 respectively). Average preop MFT was 81.1 ± 2° and postop was 87.6 ± 2.6° and preop SBT was 171.9 ± 2.7° and postop was 177.6 ± 2.6°; both showing significant improvement after spring cranioplasty (both P ≤ .001). Conclusion: Our experience and early outcomes with spring cranioplasty for UCS demonstrates that when used in younger patients (<5 months) cranial springs can be a safe and effective strategy to minimize skull base scoliosis, facial scoliosis, and orbital asymmetry, as well as increase intracranial volume. Although long-term data needs to be assessed, we are optimistic that early correction of cranial base scoliosis will translate to stable results as patients reach dentoskeletal maturity.