Anterior Skull Base Surgery Research Articles

Variations of Anterior Skull Base Seen on Computed Tomography Scans of the Paranasal Sinuses

Abstract Context: The anterior skull base (ASB) and the paranasal sinuses are known for anatomical variations. Therefore, a preoperative assessment for the assessment of these variations is a necessity. This study aims to determine the profile of variations of the ASB using computed tomography of the paranasal sinuses (CT-PNS) scans. Settings and Design: Observational Study. Materials and Methods: Forty CT-PNS scans were studied with measurement of different parameters. Statistical Analysis: Observational study analysis – Descriptive stats, t-tests, Chi-square, nonparametric tests, analysis of variance, regression, P < 0.05 significance level. A significance level of P < 0.05 was used for all tests. Results: Seventeen male and 23 female CT-PNS scans were studied. Different measurements on the right and left sides, as well as between genders, were examined and compared. The supraorbital ethmoidal cell is the most often seen anatomical variation. Variations in the ASB are equally visible on both sides in men and on the right in females (Type-II > Type-1). Type I was more common among female, whereas Type II was more common. The existence of the anterior ethmoidal foramen is a dependable marker for the anterior ethmoidal artery. In the group under investigation, there was no lamina papyracea abnormality. Conclusion: This study aims to assess anatomical variations in the Indian population undergoing ASB surgeries, contributing to the current understanding of Indian paranasal sinuses and skull base dynamics.

Translation, adaptation, and validation of ASK nasal-12 into Brazilian Portuguese

ObjectiveTranslate, adapt, and validate the Anterior Skull Base Nasal Inventory 12 questionnaire (ASK Nasal-12) to Brazilian Portuguese. MethodsA prospective longitudinal observational study was developed at the Skull Base Surgery Center clinic of the Irmandade Santa Casa de Misericórdia de São Paulo. There were five stages to translating the original ASK-12 questionnaire: two independent translations, consensus between the two, back-translation, comparison, and revision for the semi-final version. Internal consistency, reliability, and validation with a previous already validate questionnaire were all assessed. ResultsOver 30 months 72 patients in total were included in the study, of which six had to be excluded afterwards according to the research criteria. The internal consistency using Cronbach’s Alpha was calculated and successful. Next the reliability and agreement between the test and retest were analyzed. The Minimally Important Clinical Difference (MCID) was calculated for the 13 scores at each of the four time points. Finally, the final translated version was validated with the SNOT-22 questionnaire. ConclusionThe translation, adaptation, and validation of the ASK Nasal-12 questionnaire into Brazilian Portuguese appear consistent and effective regarding its cultural equivalence for monitoring the QOL of patients undergoing transnasal access for endoscopic anterior skull base surgeries. Level of evidenceII.

Long term results with medpor® reconstruction of the anterior skull base at a single institute

Objectives To evaluate a technique of multi-layered CSF repair following endonasal anterior skull base surgery using medpor graft. Design Retrospective review of consecutive case series from a single centre. Subjects 68 cases of repair of CSF leaks utilising medpor identified from a larger prospectively maintained database of endonasal endoscopic procedures at our centre. Methods Retrospective review of a database of consecutive anterior skull base cases from 2016–2022, and further data collection from electronic hospital records. Results During follow up there were 7 cases of post-op CSF leak (10.3%). There were no radiological complications, and no cases of medpor removal or extrusion. Rates of infection were low, there were 3 (4.4%) cases of confirmed bacterial meningitis within our cohort. The mean length of stay was 4.7 days (median 3 days), with 16 cases discharged on the first post-operative day. Conclusions Our experience of using medpor in anterior skull base reconstruction demonstrates that medpor is a readily available, easily handled, and reliable graft option with relatively low rates of infection and post-op CSF leak. Its use reduces the use of autologous graft materials and the associated donor site morbidity. Our long term follow up data further demonstrates the safety and efficacy of this technique.

Anatomical Measurement as a Reference for Functional Endoscopic Sinus Surgery Based on CT Scans and Dissections.

Introduction Diseases of the paranasal sinuses, nasal cavities, and those related to the skull base can be treated with nasal endoscopic surgery. Anatomical references are essential to safely perform these surgeries. Objective To measure and compare the distance from the posterior wall of the maxillary sinus to the anterior skull base in cadavers and on computed tomography (CT) scans to determine a measurement as an anatomical reference in imaging exams for sinus and anterior skull base surgery. Methods In dissections and CT scans, we took measurements from the most upper and medial point of the posterior wall of the maxillary sinus (point A) to the point where the skull base deflects and the anterior sphenoid wall is formed (Δ 90°; point B), in the right and left nasal cavities. We used 51 cadavers aged ≥ 18 years in the present research. Results The measurements obtained from CT scans and dissections were greater than 1.5 cm in all cadavers, and they were positively correlated. The 1-cm increase in the AB-tomography measurement corresponded to the 1.08-cm increase to the right and 1.07-cm to the left in the AB-dissection measurement. Conclusion The CT measurements may be considered a reliable tool to promote safe and effective access to the paranasal sinuses, matching the distance that should be dissected until the anterior base of the skull.

A Case of Olfactory Neuroblastoma Developing Bilateral Retropharyngeal Lymph Node Metastasis 14-years After Skull Base Surgery.

Olfactory neuroblastoma (ONB) is an uncommon malignant tumor and is usually treated by a multidisciplinary approach includes surgery, radiotherapy, and chemotherapy. A 62 years-old male had a tumor in the nasal cavity and diagnosed as ONB with Kadish A stage. Anterior skull base surgery was performed as radical treatment. Since the surgical margin was negative, no postoperative radiotherapy was administered. 14 years after the surgery, bilateral otitis media with effusion (OME) was occurred, we found the recurrence tumor at bilateral retropharyngeal lymph node (RPLN) which surrounded the internal carotid arteries. Since these were unresectable, we planned chemoradiotherapy which was 70Gy of intensity modulated radiotherapy combined with two courses of carboplatin and etoposide. The tumor volume was reduced and bilateral OME were improved. He has been alive for 3 years after salvage treatment. Although ONB has a relatively good prognosis, it is known to often cause cervical lymph node metastasis. Grades III and IV of Hyams classification are considered high risk. This case, initial tumor was limited in the nasal cavity and its clinical classification was early stage, but Hyams classification was grade III. In reference to this case, considering that RPLN metastasis are difficult to radically resect at the salvage surgery, including this area in postoperative radiotherapy was considered an option.

Reconstruction of the Large Frontal Sinus Defect With the Small Supporting Bone Pieces in Neurosurgical Anterior Skull Base Surgery

BackgroundLarge defects of frontal sinus (FS) might be difficult to manage effectively. Mismanagement of the large defects could lead to serious postoperative complications in anterior skull base surgery. This study introduces a simple and reliable method applying small supporting bone pieces to cover or insert into large FS defects, then the large defect of FS was transformed into the some small defects which can be sealed by bone wax successfully. MethodsEleven patients underwent anterior skull base surgery for lesions or aneurysms, with the reconstruction of large FS defects by small supporting bone pieces. During craniotomy, mild violations of the FS mucosa were spared and sterilized, while severe violations required mucosal removal. Small supporting bone pieces were obtained from the inner plate of the bone flap, and carefully covered or inserted into the large defects. The large defects were transformed into some small ones, which could be sealed effectively by bone wax. Demographic, intraoperative, and postoperative complication data were collected. ResultsFour patients had severe mucosal violations requiring removal, while seven had mild violations sparing the mucosa. All underwent effective reconstruction with small supporting bone pieces. Median follow-up was 6 months. All cases showed effective FS morphology reconstruction, with no FS-related complications. ConclusionApplying the small supporting bone pieces for large FS defect reconstruction can restore the FS morphology, preserve physiological function, and avoid postoperative complications.

Salvage skull base surgery after proton beam therapy for recurrent sinonasal malignancies: A retrospective study.

This study aimed to examine treatment outcomes and postoperative complications associated with salvage skull base surgery following radical proton beam therapy (PBT). Nine patients who underwent salvage skull base surgery following curative PBT as the initial treatment at our institution between September 2002 and May 2023 were retrospectively reviewed. The cohort comprised four males and five females with a mean age of 48.1 years. The average proton dose administered during initial therapy was 68.5 Gy (relative biological effectiveness). Among the salvage surgeries, eight were anterior skull base surgeries, and one was an anterior middle skull base surgery. No local recurrences or perioperative deaths were observed. Postoperative complications occurred in three patients (33.3%), all experiencing surgical site infections, with one also having cerebrospinal fluid leakage. The study demonstrates that salvage skull base surgery after PBT effectively achieves local control and safety in patients with recurrent sinonasal malignancies.

Exploring the influence of nasal morbidity on quality of life following endoscopic endonasal skull base surgery: a retrospective cohort study of 95 patients

The endoscopic endonasal approach is more disruptive to normal anatomy (particularly nasal mucosa) than the transseptal submucosal microscopic approach. This may result in greater postoperative nasal morbidity, in turn reducing quality of life. We aimed to assess the severity and time course of nasal morbidity, and its impact on quality of life, following endoscopic endonasal skull base surgery in this retrospective cohort study. We identified 95 patients who underwent endoscopic endonasal skull base surgery for anterior skull base pathologies. Nasal-specific questions from the Sino-Nasal Outcome Test-22 (SNOT-22) and the Anterior Skull Base inventory (ASB-12) were combined with quality-of-life questions. Patient demographics, diagnosis, and operative data were collected from electronic records. Age of the cohort ranged from 14–83 years. Time elapsed since surgery ranged from 3–85 months. 85/95 (89%) felt that nasal morbidity associated with surgery was acceptable, given the underlying reason for, and outcome of surgery; 10/95 (11%) did not. 71/95 (75%) reported no change or improvement in olfaction 3-months following surgery. 24/95 (25%) reported a deterioration in olfaction which was mild in 7%, moderate in 7%, and severe in 11%. Nasal crusting, nasal obstruction, and headache were moderately problematic symptoms but improved significantly by 3-month follow-up. Nasal discharge, nasal pain, and nasal whistling were mildly problematic and improved significantly by 3-months. 62/95 (65%) patients reported ‘no change’ in day-to-day activities due to the effects on their nose after surgery. 19/95 (20%) had ‘mild inconvenience’, 8/95 (8%) ‘moderate inconvenience’ and 6/95 (6%) ‘severe inconvenience’. Endoscopic anterior skull base surgery is associated with nasal morbidity. Whilst 35% of patients appreciate a consequent negative impact on day-to-day life, the overwhelming majority feel that nasal morbidity is acceptable, given the wider surgical goals.

Bilateral infraoptic origin of the anterior cerebral artery: illustrative case.

A bilateral infraoptic origin of the anterior cerebral arteries (ACAs) is a rare anatomical variant that can be encountered during anterior skull base surgery. The ACAs arise from the internal carotid artery (ICA) at the level of the ophthalmic artery and course medially, traveling inferior to the ipsilateral optic nerves. Herein, the authors discuss the different configurations of the anatomical variant, its prevalence, and hypotheses leading to the variable configuration of this anomaly. A 67-year-old woman presented with worsening dizziness over a week-long period and was found to have a large left sphenocavernous meningioma with optic, cavernous, and suprasellar extension. The tumor incorporated the left supraclinoid ICA and its branches. She underwent a left modified orbitozygomatic craniotomy for tumor resection. Early identification of the aberrant ACA anatomy was crucial in avoiding vascular injury. While this variant is typically encountered during the treatment of vascular pathologies-namely, intracranial aneurysms-its existence should be kept in mind during the treatment of any anterior skull base pathology. Failure to account for the presence of this variant may lead to potential intraoperative complications.

Skull base surgery in the German DRG system-New categorization of important procedures

Surgery of the skull base includes interventions between the nose or paranasal sinuses (anterior skull base) or ear/temporal bone (lateral skull base) and the intracranial space. As interventions at the anterior skull base almost exclusively involve complex pathologies in ademanding anatomical region, in many cases two experienced surgeons from different disciplines are required who should be experienced in operating together. The technical and time requirements are also considerable in many cases; however, for many procedures there are no specific skull base operational and procedural keys (OPS) codes that take the considerable personnel and structural effort into account. Achange in the diagnosis-related groups (DRG) system, implemented since the beginning of 2023, now adjusts the remuneration of the abovementioned effort for malignant pathologies of the anterior and lateral skull base. The reallocation of procedures 5‑015.0/1/3/4 and 5‑016.0/2/4/6 results in asignificant upgrade of anterior and lateral skull base surgery. Since the beginning of 2023 skull base surgery will no longer be charged under DRG D25C with a(former) relative weight of 1.893, but with DRG D25B with acurrent relative weight of 3.753 when acode of the aforementioned groups is used. Nevertheless, further adjustments are necessary, for example, in the available reconstructive steps in order to provide the Institute for the Remuneration System in Hospitals (InEK) with the most differentiated data possible on the procedural effort of the intervention and to achieve amore balanced distribution of the reimbursements of skull base surgery in the long term.

Evaluation of The Three-Dimensional Endoscopy in Basic and Extended Nasal Procedures: A Clinical and Cadaveric Study.

Introduction The three-dimensional (3D) endoscope is considered a new surgical tool used in different approaches in intranasal and anterior skull base surgical procedures. There are many advantages of 3D over two-dimensional (2D) endoscopy that have been demonstrated in clinical applications, surgical training, and different experimental studies. Objective To show the difference between using the 3D and 2D endoscopes during endonasal and anterior skull base surgery and its importance. Methods Our study is divided into two phases (clinical and cadaveric phases). In the clinical study we, have performed 52 endonasal and anterior skull base surgical procedures (26 study cases and 26 control cases). We recorded accuracy, duration, and intraoperative complication for each case. The cadaveric study was performed on three cadavers. Differences in accuracy and dissection time were recorded using 3D and 2D endoscopy for each side chosen by randomization. Results In the clinical study, the cases done by 3D endoscope were significantly faster and more accurate with less intraoperative complications compared with cases done using 2D endoscope. In cadaveric dissection, while using 3D endoscope, there was better depth of perception regarding the anatomical landmarks compared with 2D endoscope. Conclusion Three-dimensional endoscopy is an advanced instrument that allows better training for the coming generation of ear, nose, and throat surgeons. Both clinical and cadaveric studies offer a promising outcome in both endonasal and anterior skull base surgery.

410 Is a Single Dose, Single Agent Peri-Operative Antibiotic Protocol Adequate for Endoscopic Endonasal Skull Base Surgery? A 14-Year Review of 574 Cases

Abstract Post-operative meningitis is a rare but potentially fatal complication of endoscopic endonasal skull base surgery. As endonasal approaches to the skull base are clean-contaminated procedures, peri-operative antibiotics are routinely used. We sought to analyse the safety and efficacy of a single agent, single dose protocol in cases of endonasal anterior skull base surgery. Database of all endonasal anterior skull-base procedures performed in ENT Department at Leeds General Infirmary between 2008 and February 2022 was prospectively recorded. The primary outcome measure was development of meningitis within 30-days of surgery. Our protocol uses single dose of IV co-amoxiclav 1.2g (or teicoplanin if allergy precludes co-amoxiclav). The data was further divided according to primary or revision surgery, the presence or absence of intra-operative CSF leak, and the development or not of a post-operative CSF leak. Over the 14-year period, 574 endoscopic endonasal operations that fulfilled inclusion criteria were performed. The overall rate of post-operative meningitis across the entire cohort was 2.6%(n = 15). Among the 15 cases:80% (12/15) had intra-operative CSF leak47% (7/15) were revision cases73% (11/15) had extended endoscopic approach as pathology that required an intentional opening of the arachnoid80% (12/15) had post-operative CSF LeakThere were no cases of meningitis following repair of long-standing CSF fistula or encephalocele and surgery for sinonasal tumours with skull-base involvement. In conclusion, a single dose of 1.2g intravenous co-amoxiclav (or teicoplanin) is safe in the context of sellar-centred pathologies, repair of pre-existing spontaneous CSF leaks, and surgery on sinonasal tumours with skull base involvement.

The Impact of Endoscopic Endonasal Surgery on Quality of Life in Patients with Malignant Tumors of the Anterior Skull Base: A Prospective Study.

To investigate the effects of endoscopic endonasal surgery (EES) on longitudinal quality of life (QoL) in patients with malignant tumors of the anterior skull base. Eligible patients prospectively completed the Anterior Skull Base Surgery Questionnaire (ASBQ) and the 22-item Sino-Nasal Outcome Test (SNOT-22) questionnaires in referring to 3 different periods throughout their treatment and recovery. Forty patients were included. The median volume coronal maximum length of the tumor was 3.6 cm (95% CI 2.7-4.1cm). Overall QoL significantly worsened at 1 month postoperatively but returned to baseline after 1 year. Unrelieved symptoms in specific domains prompted further evaluation of individual items. Transient worsening of taste (p=0.011) and olfaction (p=0.004) lasted for 1 month but gradually relieved within the first postoperative year, but vision consistently worsened over the course of the treatment (p=0.126). Age>50 years (p<0.001), comorbidities (p<0.001), tumor necrosis (p<0.001) and recurrence (p=0.001) were associated with worse preoperative QoL. Poor long-term QoL was noted in those undergoing adjuvant therapy (p=0.032). Overall ASBQ scores (p=0.024), subdomain scores in specific symptoms (p=0.016), and vision scores (p=0.009) were worse only in patients with the greater coronal maximum diameter at 1-month postoperatively. Greater coronal maximum diameter was related to worse preoperative subdomain scores regarding specific symptoms (p=0.030) and decreased postoperative long-term decreased vision scores (p=0.014). Long-term site-specific and sinonasal QoL eventually stabilized after EES. Greater coronal maximum diameter was significantly associated with worsened vision function. Temporarily worse olfactory, vision, and taste function may be tied to decreased short-term QoL.

Impact of sinonasal anatomic changes after endoscopic anterior skull base surgery on nasal airflow and air conditioning: a computational fluid dynamics study

Objective: To analyze the impact of the sinonasal anatomic changes after endonasal endoscopic anterior skull base surgery on the nasal airflow and heating and humidification by computational fluid dynamics (CFD), and to explore the correlation between the postoperative CFD parameters and the subjective symptoms of the patients. Methods: The clinical data in the Rhinology Department of the First Affiliated Hospital of Zhengzhou University from 2016 to 2021 were retrospectively analyzed. The patients received the endoscopic resection of the anterior skull base tumor were selected as the case group, and the adults whose CT scans had no sinonasal abnormalities were chosen as the control group. The CFD simulation was performed on the sinonasal models after reconstructed from the patients' sinus CT images during the post-surgical follow-up. All the patients were asked to complete the Empty Nose Syndrome 6-Item Questionnaire (ENS6Q) to assess the subjective symptoms. The comparison between two independent groups and the correlation analysis were carried out by using the Mann-Whitney U test and the Spearman correlation test in the SPSS 26.0 software. Results: Nineteen patients (including 8 males and 11 females, from 22 to 67 years old) in the case group and 2 patients (a male of 38 years old and a female of 45 years old) in the control group were enrolled in this study. After the anterior skull base surgery, the high-speed airflow moved to the upper part of the nasal cavity, and the lowest temperature shifted upwards on the choana. Comparing with the control group, the ratio of nasal mucosal surface area to nasal ventilation volume in the case group decreased [0.41 (0.40, 0.41) mm-1 vs 0.32 (0.30, 0.38) mm-1; Z=-2.04, P=0.041], the air flow in the upper and middle part of the nasal cavity increased [61.14 (59.78, 62.51)% vs 78.07 (76.22, 94.43)%; Z=-2.28, P=0.023], the nasal resistance decreased [0.024 (0.022, 0.026) Pa·s/ml vs 0.016 (0.009, 0.018) Pa·s/ml; Z=-2.29, P=0.022], the lowest temperature in the middle of the nasal cavity decreased [28.29 (27.23, 29.35)℃ vs 25.06 (24.07, 25.50)℃; Z=-2.28, P=0.023], the nasal heating efficiency decreased [98.74 (97.95, 99.52)% vs 82.16 (80.24, 86.91)%; Z=-2.28, P=0.023], the lowest relative humidity decreased [(79.62 (76.55, 82.69)% vs 73.28 (71.27, 75.05)%; Z=-2.28, P=0.023], and the nasal humidification efficiency decreased [99.50 (97.69, 101.30)% vs 86.09 (79.33, 87.16)%; Z=-2.28, P=0.023]. The ENS6Q total scores of all patients in the case group were less than 11 points. There was a moderate negative correlation between the proportion of the inferior airflow in the post-surgical nasal cavity negatively and the ENS6Q total scores (rs=-0.50, P=0.029). Conclusions: The sinonasal anatomic changes after the endoscopic anterior skull base surgery alter the nasal airflow patterns, reducing the efficiency of nasal heating and humidification. However, the post-surgical occurrence tendency of the empty nose syndrome is weak.

The impact of surgical set-up of endoscopic two surgeon four hand anterior skull base surgeries on surgeons' ergonomics.

The impact of different surgical set-ups of endoscopic two surgeon four hand anterior skull base surgeries on surgeons' ergonomics remain unclear. This study aims to explore the effect of surgeon, patient and surgical screen positioning on surgeons' ergonomics using the Rapid Entire Body Assessment (REBA) tool. A total of 20 different surgical positions of anterior skull base surgery were simulated and the ergonomic impact on surgeons' neck, truck, leg and wrist were measured using the validated Rapid Entire Body Assessment (REBA) tool. To investigate the ergonomic effect of different surgical setups, the operating surgeon, assisting surgeon, patient head, camera and screen positions were positioned differently in each surgical position. The lowest REBA Score recorded is 3 whereas the highest score is 8. The REBA scores for the majority of positions are 3 highlighting that these positions are ergonomically favorable. Position 12 is the least ergonomically favorable position with a total REBA score of 19. In this position, operating surgeon is positioned to the right of the patient, assisting surgeon to the left of patient, patient head in central position with camera held by operating surgeon and one screen is placed to the right of patient. Positions 13 and 17 are the most ergonomically favorable positions with a total REBA score of 12. In these positions, the patient's head is positioned to the center, two screens were utilized, and the surgeons were positioned on either side of the patient. The utilization of 2 screens with a central patient head position with the surgeons placed on either side of the patient contribute towards a more ergonomically state in these positions. Certain positional behaviors are better at reducing musculoskeletal injury risk when compared to other. Positions with two screens and central head positions are more favourable ergonomically and surgeons should consider this set-up to reduce musculoskeletal injuries during anterior skull base surgery.

Incidence of Ossification of Caroticoclinoid Ligament in Dry Adult Human Skulls with its Surgical Implications: A Cross-sectional Study from Telangana Region, India

Introduction: The caroticoclinoid ligament extends from the Anterior Clinoid Process (ACP) to the Middle Clinoid Process (MCP). Occasionally, it gets ossified and forms the caroticoclinoid foramen. Anterior clinoidectomy is a common surgical procedure to treat internal carotid artery aneurysms or pituitary tumours. Abnormal ossification of the caroticoclinoid ligament may lead to intraoperative or postoperative complications as it is not normally present. Aim: To find out the incidence of ossification of the caroticoclinoid ligament in adult human skulls. Materials and Methods: This was an observational crosssectional study that included 100 dry adult human skulls collected from the Department of Anatomy, Gandhi Medical College, Secunderabad; Osmania Medical College, Hyderabad; Bhaskar Medical College, Moinabad, Telangana, India, from January 2021 to February 2023. Adult human skulls with open vault were included. All the skulls were observed and skulls damaged in the clinoid regions were excluded from the study. The skulls were observed for the presence of any ossifications of the caroticoclinoid ligaments and the observations were noted. The qualitative data was presented as number and percentage was calculated. The data was recorded in MS excel version 2021. Results: The incidence of ossification of caroticoclinoid ligament was 8 (8%). The incidence was higher on right-side when compared to the left-side. Bilateral complete ossification of the caroticoclinoid ligament was observed in 2 (2%) skulls; bilateral incomplete ossification was observed in 3 (3%) skulls, unilateral complete ossification was observed in 2 (2%) skulls on the right-side. In one skull 1 (1%), complete ossification was observed on the right-side and incomplete ossification was observed on the left-side. Conclusion: Knowledge of the ossification of the caroticoclinoid ligament is important for neurosurgeons while performing anterior clinoidectomies or skull base surgeries. Radiological confirmation of the ossification of the caroticoclinoid ligament is essential to avoid complications.

Use of BoneScalpel Ultrasonic Bone Dissector in Anterior Clinoidectomy and Posterior Fossa Surgery: Technical Note.

BackgroundFirst popularized by Dolenc, anterior clinoidectomies were performed with rongeurs, before the adoption of modern high-speed drills. We describe a novel application of the piezoelectric BoneScalpel™ in anterior skull base and posterior fossa surgeries. In the literature, to date, there are no mentions of anterior clinoidectomies performed with piezosurgical devices.MethodsWe reported a total of 12 patients, 8 affected by posterior fossa tumors and 4 treated for anterior skull base oncologic and vascular pathologies. This study aims to assess the safety and efficacy of the piezoelectric osteotomy in skull base and posterior fossa surgeries. In all patients, an ultrasonic bone dissector (BoneScalpel™ - Misonix) was used to perform the anterior clinoidectomy (AC) and craniotomy.ResultsA successful clinoidectomy was performed in 4 out of 12 patients (33.3%). We did not notice any heat damage to the surrounding soft tissue in critical areas such as paraclinoid structures. We documented only one durotomy in an oncologic patient, while no lesions of SSS or TS were detected.We recorded only a slightly increased surgery duration in the PIEZOSURGERY® and BoneScalpel™ group, compared to standard surgery with an osteotome to perform craniotomies, but no time difference in performing the clinoidectomy between BoneScalpel™ and a conventional high-speed drill.ConclusionWe report the first experience with piezosurgery for anterior clinoidectomy. There is no time difference in performing the clinoidectomy between BoneScalpel™ and a conventional high-speed drill, and this is an undoubted advantage in critical contexts such as clinoid-paraclinoid surgeries, where the risk of dural sinuses tears is common.

Bilateral Persistent Primitive Olfactory Arteries Observed During Resection of Olfactory Groove Meningioma: Technical Case Report.

Resection of olfactory groove meningiomas is challenging because of their close proximity with the anterior cerebral circulation. It is important to recognize the vascular variants in procedures at the anterior skull base because inadvertent maneuvers may result in the rupture of these arteries and unexpected bleeding. We reported a type 2 persistent primitive olfactory artery with a dural branch of the elongated anterior cerebral artery directly to the ethmoid region, visualized during the surgical removal of an olfactory groove meningioma. This is the first report of bilateral persistent primitive olfactory artery demonstrated by operative visualization and confirmed with vascular study. Understanding and recognizing the possible variations of this vascular anatomy is of great importance for anterior skull base surgeries.

Current Trends in Endoscopic Ear Surgery.

Current Trends in Endoscopic Ear Surgery.

An institutional analysis of the outcomes of endonasal endoscopic anterior skull base surgery

Endoscopic skull base surgery is an emerging surgical technique that recolonized the resection of skull base lesions. The present study analyzed the outcome of the endoscopic endonasal anterior skull base.A retrospective data review ofendoscopic endonasal anterior skull base surgeries performed from 2017 to 2022. Minimum follow-up was done 6 months postoperatively.: 63 cases of anterior skull base pathologies have been operated out of which 2 cases of meningioma, 3 cases of meningoencephalocele, 5 olfactory neuroblastoma, 18 angiofibroma extending till anterior skull base, 8 CSF rhinorrhea repair, 12 pituitary macroadenoma, 8 cerebral Mucormycosis and 7 sino-nasal mass with intracranial extension have been operated. Residual disease was left in 10 cases, the rest all the masses were completely removed. The overall complication rate was 28.6 percent. Three mortalities occur a few months post-operatively of which 2 were cerebral mucormycosis and one was sino-nasal malignancy with intracranial extension.Endoscopic endonasal anterior skull base surgeries are safe surgical procedure that provides a high degree of disease clearance and negligible complications.