Middle Fossa Research Articles

The Use of Synthetic, Nonabsorbable Graft for Middle Fossa Repair in Patients With Spontaneous Cerebrospinal Fluid Leak: A Pilot, Prospective Study.

To evaluate the efficacy of a nonabsorbable, synthetic graft for the reconstruction of spontaneous middle fossa (sMF) cerebrospinal fluid (CSF) leaks. Six adult patients (age ≥16 yr) who had sMF CSF leaks surgically repaired within an 18-month period at a single university hospital using synthetic, nonbiological, nonabsorbable graft (Neuro-Patch) and a retrospective control group of five patients undergoing multilayer MF repair with autologous grafts. MF repair through a combined transmastoid/MF approach using Neuro-Patch or multilayer autologous grafts. The incidence of postoperative leak within 6 months postoperatively was the main outcome measure; we also recorded the need for lumbar drain, additional hearing loss, length of inpatient stay, body mass index, previous meningitis, preoperative increased intracranial pressure, and age. In the Neuro-Patch group, there was no postoperative CSF leak without the need for lumbar drain. We observed no additional hearing loss; patients were monitored for 2 days without any readmissions. Increased intracranial pressure (four of six), previous episodes of meningitis (two of six) or obesity (five of six) did not affect patient outcomes. Demographic and prognostic factors were the same for the control group. However, one patient needed lumbar drain postoperatively because of residual leak; lumbar drain was used in one more case (two of five cases), whereas three of five patients had to stay for longer than 2 days (5 d). Our pilot study suggests the use of Neuro-Patch via combined transmastoid/MF approach as an effective technique with minimum, if any morbidity; it could be of particular benefit for patients with larger MF dura defects. A larger number of patients are required to strengthen the evidence.

Transorbital Approach Clipping of Middle Cerebral Artery Aneurysm: A Virtual Reality Morphometric Anatomic Study

The transorbital approach (TOA) has a unique advantage to the more common lateral approaches as it provides direct access to the anterior middle fossa and medial sylvian fissure (SF) without significant dissection or retraction. However, when to use the TOA for surgical treatment of MCA aneurysms remains unclear. This study details the feasibility of clipping unruptured middle cerebral artery (MCA) aneurysms via the TOA by highlighting the anatomic features that either facilitate or hinder the approach. Virtual reality (VR) models of 25 MCA aneurysms from CT angiograms of actual patients were rendered with the relevant anatomic structures, including the neighboring temporal lobe and SF. TOA was performed on the models in VR and the globe was translated medially and inferiorly, replicating retraction used intraoperatively. Anatomic data, including the area of surgical freedom (AOF) at the aneurysm, were recorded. Trials of aneurysm clipping were conducted in VR and each aneurysm was classified as "possible" or "impossible" candidates for clipping via TOA. Separately, the relationship between surgical view and SF visualized was analyzed. Sixteen aneurysms were eliminated as candidates for TOA treatment either through VR clip trial and/or because the SF was inaccessible. The remaining 9 (36%) were candidates for TOA. Comparing the details of these two aneurysm categories with Mann Whitney U tests, there was a statistically significant difference in the AOF of the TOA approach and the width of the aneurysm dome. A clinical case report is also provided highlighting the VR rehearsal similarity with surgery. Given the minimally-invasive, technically-challenging approach, the feasibility and safety of TOA for MCA aneurysms must be evaluated before wide clinical adoption. This study identified AOF, aneurysm width, and SF accessibility as three features that may significantly impact the possibility of clipping MCA aneurysms via TOA.

Middle fossa arachnoid cyst fenestration for ruptured cysts associated with subdural collections: paediatric neurosurgery tertiary unit experience.

Arachnoid cysts are commonly encountered benign cystic structures and often come to attention as incidental findings following cranial imaging. Surgical intervention rates vary in different studies; however, rupture of cyst and subdural collection with mass effect are some of the indications for surgical intervention. In this study, we aimed to evaluate our operated cohort of middle fossa arachnoid cysts to determine the rate of traumatic subdural collection in this cohort and further assess outcomes. A retrospective review of all consecutive operated middle cranial fossa arachnoid cysts was carried out for the period 2010 to 2024. Demographics including age, sex, Galassi type, surgical technique for fenestration, preceding history of trauma, presence of papilloedema, and complications following surgery were extracted. Indication for surgery included papilloedema and headaches or increasing head circumference or rupture and subdural collections. Arachnoid cysts managed with CSF diversion as primary surgery were excluded. Over the study period, 21 fenestrations of the arachnoid cysts were carried out in 19 patients with mean age of 7years and M:F ratio of 2.2:1 (laterality: 9 right-sided and 10 left-sided). These included seven Galassi 2 and twelve Galassi 3 arachnoid cysts. At presentation, 10 had papilloedema, 5 with no papilloedema, and 4 with no available ophthalmological assessment. Fenestration of cyst included 12 microscopic, 6 endoscopic, and 3 combined approaches. Of the operated cohort, 8 were due to rupture of arachnoid cyst and subdural collections causing mass effect. Of 8 cases of ruptured arachnoid cyst with subdural collections, 75% had clear history of preceding head injury in the context of accidental or sports-related injuries. Two patients required redo-fenestration (10.5%), 1 patient required temporary lumbar drain (5.2%), and 2 patients required cysto-peritoneal shunts (10.5%). Rupture of arachnoid cysts and subdural collections although rare can be associated with head injury in majority of cases. All operated cases belonged to grade 2 and 3 Galassi.

Epidermoid Cyst at the Root of the Sphenoidal Pterygoid Process: A Rare Case Report.

Epidermoid cysts of the skull base are rare. We present the case of a woman with an epidermoid cyst at the root of the sphenoidal pterygoid process. She experienced tightness of the forehead skin without headache. Computed tomography (CT) scan revealed a hypodense lesion at the base of the skull in the right middle cranial fossa, which had partly eroded the pterygoid root. Magnetic resonance imaging (MRI) scan revealed a soft cystic mass that eroded the pterygoid root with hypo-/iso-intense on T1-weighted images, hyperintense on T2-weighted images, inhomogeneous hyperintense on diffusion-weighted images, a slightly low apparent diffusion coefficient, and no enhancement, suggesting a diagnosis of an epidermoid cyst. Surgical excision was performed using a nasal endoscope via the pterygoid process-root approach. A histopathological examination confirmed the diagnosis of an epidermoid cyst. At the 6-month follow-up, no recurrence was found on MRI or nasal endoscopy, and the symptoms of forehead tightness disappeared. In conclusion, epidermoid cysts at the root of the sphenoidal pterygoid process are exceptionally rare. Preoperative MRI and CT scans are necessary for the correct diagnosis and differentiation of other low-growing lesions. Nasal endoscopy is crucial for surgical excision and postoperative follow-up for potential recurrence.

A Proposal for Comprehensive Audio-Vestibular Test Battery Protocol for Diagnosis and Follow-Up Monitoring in Patients with Vestibular Schwannoma Undergoing Surgical Tumor Removal.

Background: A vestibular schwannoma (VS) is a benign tumor, causing audiological and vestibular symptoms. This study aimed to propose a comprehensive audio-vestibular test battery protocol for diagnosis and follow-up monitoring in patients with unilateral VSs undergoing surgical removal. Methods: The detailed interpretation of audiological and vestibular findings was presented in two example cases. The surgery was performed through the middle cranial fossa (#1) and translabyrinthine approach (#2). The participants were evaluated with tonal, speech, and impedance audiometry, ABR, caloric test, vHIT, cVEMP, oVEMP, SOT, and DHI. Patient and tumor characteristics were retrieved from the patient's history. Results: In the postoperative period, the reduction in gain of the lateral semicircular canal was observed in the vHITs of both patients. The DHI in case #1 increased after surgery, while it decreased in case #2. The improvement in postural performances compared to the preoperative SOT (CON 5, CON 6, composite score) and immediately after the procedure was observed. Conclusions: A specific diagnostic protocol is necessary to compare the results of different surgical techniques and approaches. Diagnostic tests performed before the surgery should be repeated within a specific time frame during postoperative follow-up to enable the comparison of results. The proposed protocol can help us better understand the processes ongoing during tumor growth and postoperative vestibular compensation.

Posterior clinoid process in children: morphometric analysis, pneumatization ratio, and surgical implications.

To describe pneumatization and topographic position of the posterior clinoid process (PCP) in healthy children when approaching the anterior and middle fossae. The study consisted of computed tomography images of 180 pediatric patients (90 males / 90 females), aged 1-18years. The presence or absence of PCP pneumatization was noted, and the distances of certain landmarks to PCP were measured. The distances of the foramen ovale, foramen rotundum, superior orbital fissure, anterior clinoid process (ACP), foramen magnum and crista galli to PCP were measured as 18.59 ± 3.36mm, 15.37 ± 3.45mm, 14.60 ± 3.05mm, 5.27 ± 3.24mm, 32.03 ± 3.27mm, and 30.45 ± 3.93mm, respectively. These parameters increased with growth (between 1-18years), but the distance between PCP and ACP decreased with an irregular pattern. In 11 sides (3.10%), a fusion between PCP and ACP was determined. PCP pneumatization was identified in 32 sides (8.9%). Its pneumatization correlated with pediatric ages (p < 0.001), but not gender (p = 0.459) or side (p = 0.711). Most of PCP pneumatization appeared after late childhood period (i.e., between 10-18years). Our study provides beneficial data for neurosurgeons to use PCP as a reference point for creating a skull base map in children, because of the incomparable position of PCP in the skull base center.

Technical note: durable resolution of hydrocephalus after ultrasound-guided percutaneous fenestration of giant suprasellar arachnoid cyst in a neonate.

Arachnoid cysts are relatively common, but rarely require intervention. While most arachnoid cysts in typical middle or posterior cranial fossa locations are seldom symptomatic, suprasellar cysts may become symptomatic due to the potential for ventricular outflow obstruction and hydrocephalus. Typical standard of care for the treatment of these lesions is endoscopic fenestration with third ventriculostomy, or the placement of ventriculoperitoneal or cystoperitoneal shunts. The surgical and anaesthetic risks of traditional interventions may be higher in the early neonatal period, including leak of cerebrospinal fluid, infection, and premature failure of ventriculostomy or shunts. This note describes a novel bedside ultrasound-guided technique to percutaneously fenestrate large suprasellar arachnoid cysts under local anaesthesia. The technique involves insertion of a 25-g spinal needle until contact with the membrane of the arachnoid cyst medially, followed by a lateral sweeping to widely incise/fenestrate the lesion into the ventricular space under continuous ultrasound visualisation. This note describes an example case which demonstrates durable radiological and clinical improvement after 2years of follow-up. This may represent a management option to temporise, or perhaps definitively manage suprasellar arachnoid cysts in the neonatal period.

Endoscopic endonasal drainage of a middle fossa epidural abscess in conjunction with endoscopic sinus surgery: illustrative case.

Recent anatomical studies have reported the feasibility of the endoscopic endonasal approach to the middle fossa. However, its clinical applicability has been discussed in only a few cases. This article describes the case of a middle fossa epidural abscess successfully drained through a fully endoscopic endonasal corridor and discusses the key technical points. The authors describe an 8-year-old boy who presented with worsening headache, fatigue, emesis, and fever and was diagnosed with a left middle fossa epidural abscess associated with sphenoid sinusitis. Following endoscopic sinus surgery performed by a rhinologist, the middle fossa was accessed by removing the maxillary strut through the transmaxillary transpterygoid corridor. Complete drainage of the abscess was confirmed on postoperative magnetic resonance imaging. The patient tolerated the surgery without neurological deficit and demonstrated prompt symptom improvement. He was discharged home after completing a 6-week course of antibiotic therapy and remained free from recurrence at 1 year following surgery. The endoscopic endonasal approach may be applicable to a middle fossa epidural abscess, resulting in prompt clinical improvement. The maxillary strut is a key structure for entering the middle fossa. https://thejns.org/doi/10.3171/CASE24288.

Microsurgical Resection of Trigeminal Schwannoma Through Transorbital Approach: 2-Dimensional Operative Video.

We present the case of an asymptomatic 34-year-old woman who was found to have an incidental left trigeminal schwannoma.1,2 Owing to the rapid increase in size on imaging, an atypical finding for this type of lesion,3 as well as the risk of cranial nerve involvement and need for tissue diagnosis, the patient underwent a microsurgical left transorbital approach with lateral orbitotomy to resect the lesion.4,5 Piecemeal resection was performed, and the internal contents of the cavernous sinus were preserved. Ultimately, gross total resection was achieved with no residual disease identified on postoperative imaging. No new neurologic deficits were noted after surgery. The technical considerations for the transorbital approach and the literature review on the outcomes for middle fossa lesions accessed by a lateral orbitotomy are reviewed.6-10 The patient consented to the procedure and to the publication of her images. Institutional Review Board approval was deemed unnecessary due to the retrospective, case-report nature of this work.

The value of beta trace protein in CSF-leakage detection confirmed by endoscopic fluorescein evaluation.

Cerebrospinal fluid (CSF) leaks originating from defects within the anterior and middle cranial fossa typically manifest as unilateral clear watery rhinorrhea. Continuous CSF leakage mandates surgical repair due to the risk of meningitis and brain abscess. It can be categorized based on its underlying etiology into traumatic, iatrogenic and non-traumatic CSF leaks.

Outcomes at 6 months after isolated or non-isolated surgery for temporal bone cerebrospinal fluid leak in adults: A STROBE analysis

AimThe main aim of this study was to evaluate 6-month closure success in surgery for isolated or non-isolated temporal bone osteomeningeal breach (OMB). Secondary objectives were to analyze complications of closure and correlations between success and breach, treatment and patient data. Material and methodThis was a single-center retrospective observational study of patients who underwent surgery for temporal bone OMB via a middle cranial fossa or transmastoid approach in a French university teaching hospital between 2007 and 2022, with follow-up of at least 6months. Patients with superior semicircular canal dehiscence were excluded. Study data comprised gender, age, body mass index, OMB etiology, mode of discovery, audiometric and radiological data, surgical technique, length of hospital stay and postoperative complications. The primary endpoint was absence of a cerebrospinal fluid leak on MRI at 6months. Fisher's exact test or Chi2 test were used for qualitative data and Student t-test for quantitative data. ResultsThe closure success rate was 87%: 81% (3 recurrences) in the middle cranial fossa group of 16 patients and 93% in the transmastoid group of 14 patients. Postoperative audiometry showed significant improvement (P=0.0016) for air conduction in the middle cranial fossa group. Five patients (17%) operated on via the middle cranial fossa approach and 1 (7%) operated on via the transmastoid approach had postoperative complications. OMB was in the tegmen mastoideum in 8 patients (29%), tegmen tympani in 7 (25%), tegmen antri in 4 (14%), tegmina antri and tympani in 3 (11%), antri and mastoideum in 1 (8%) and in the whole tegmen in 5 (18%). Eleven OMBs were lateral to the superior semicircular canal, 13 medial and 4 on either side. ConclusionThe transmastoid approach is indicated in case of associated middle-ear procedures, patients aged over 75years or OMB lateral to the superior semicircular canal. The middle cranial fossa approach is reserved for OMB located medial to the superior semicircular canal patients under 75years of age without associated ossicular procedures. For patients with OMB medial to the superior semicircular canal who require middle-ear surgery, a combined approach can be used.

Anatomical Features and Morphometric Characteristics of the Sphenoidal Sinus in MRI Studies.

Differential access to pathological sellar processes and adjacent regions is determined by the anatomic structures identified through diagnostic imaging. Both direct endonasal access (microscopic or endoscopic) and sublabial access utilize the sphenoid sinus (SS) as the primary surgical pathway. Critical factors include the pneumatization of the sinus, its intermediate septa, and the presence of a double wall, consisting of a connective tissue membrane along the dorsal wall of the SS. The present study aims to demonstrate the significance of the size and type of the SS based on MRI measurements. The type of SS, its pneumatization, and the proximity of adjacent brain structures are crucial for different surgical approaches to the SS and pituitary fossa. In neurosurgical practice, six main types of sinuses are recognized: sphenoid body type, lateral type, clival type, lesser wing type, anterior type, and combined type. Failure to consider these variations can lead to damage to the cavernous sinus, Meckel's cave, nerve structures in the middle cranial fossa, planum sphenoidale, suprasellar region, and vital brainstem structures located on the clivus. Randomly included MRI measurements were conducted on 112 patients from Pulmed University Hospital, Plovdiv, Bulgaria, categorized into two cohorts based on gender, with mean ages of 51 years for men and 47.8 years for women. The measurements, recorded in centimeters, were obtained using two imaging software programs, RadiAnt DICOM Viewer (Medixant, Poznan, Poland) and Weasis DICOM Viewer (Nicolas Roduit, https://github.com/nroduit/Weasis). No statistically significant differences were observed between the measurements produced by the two programs. Measurements of the SS were taken in two equal groups, using three different projections: axial, sagittal, and coronal. The results for height, width, and depth showed average sizes of 2.73-3.04 cm in axial projections, 1.70-2.64 cm in sagittal projections, and 2.86-3.03 cm in coronal projections. The minor differences between axial and coronal measurements of the same parameters (height and width) are statistically acceptable and attributed to the varying angles of the MRI scans. These measurements are crucial for planning surgical access to the sellar and parasellar regions, determining the necessary bony resection of the posterior wall of the SS, and preventing complications from excessive bony trepanation.

Microsurgical Lateral Orbital Approaches to Resect Tumors within the Cavernous Sinus, Middle Fossa, and Temporal Lobe: A Systematic Review

Abstract Introduction Common approaches to remove skull base tumors invading the orbital apex, cavernous sinus, middle fossa, or temporal lobe include orbitozygomatic or fronto-orbital craniotomies. Recently, different types of orbital approaches have been described as alternative minimally invasive techniques. Objective With this systematic review, we analyzed the typology of intracranial tumors treated through transorbital approaches, especially through the lateral orbital (LO) wall, and analyzing the complication rates and outcomes. Design A PubMed/Medline search was performed using the criteria: “orbitotomy,” “transorbital,” “transpalpebral,” and “lateral orbitotomy” in combination with “cavernous sinus,” “middle fossa,” and “temporal lobe.” Main Outcome Measures From these reports, we collected diagnoses, lesion sizes and locations, approaches, outcomes, aesthetic outcomes, postoperative ptosis, postoperative cranial nerve (CN) palsies, length of CN deficits postoperatively, overall complications, and follow-up length. Results A total of 13 papers and 3 of our own cases matched our inclusion criteria totaling 160 patients. Most patients were treated for meningiomas (135, 84.4%). The approaches included the LO approach (n = 54; 33.8%), deep transorbital (n = 5; 3.1%), mini-LO (n = 91; 56.9%), and modified LO (n = 10; 6.2%). While not all cases reported excision success, the various LO approaches achieved total (n = 42; 26.25%) resection margins. Postoperative ocular complications (including CN palsies, proptosis, or ocular disturbances) totaled 46 (28.8%) new CN palsies, 23 (14.4%) occurrences of vision loss, 1 (1.7%) with worsened proptosis, 5 (3.9%) with worsened enophthalmos, and 42 (26.3%) other complications. Conclusion Microsurgical LO approaches, especially in the era of radiosurgery, may become a suitable alternative to other more established craniotomies.

Morphological and Morphometric Study of the Pterion &amp;ndash; A Cadaveric Study in Sri Lanka

Introduction: Pterion is an important landmark as its relation to the anterior branch of middle meningeal artery, Broca’s motor speech area on the left side, and surgical interventions relating to pathologies of the sphenoid ridge and optic canal as it provides access to vital structures such as sylvian fissure, circle of Willis, optic nerve, para-sellar regions, middle meningeal vessels and cavernous sinus. Approach through pterion is mostly used to treat lesions of anterior and middle cranial fossa. Pterion ossicle or Epipteric bone are sometimes mistaken as a fracture at this point.Objective: The aim is to study the types of pterions and measure the distance from various bony landmarks on skull to the midpoint of pterion.Methods: Specific measurements were taken, and type of the pterion recorded by two independent investigators in the Frankfurt plane on both sides of 37 adult dry skulls of unknown age, gender and race, without calvaria which were prepared for academic purposes, none of which showed any obvious pathology or trauma. The skulls with broken lateral walls were excluded. The linear distance from the center of the pterion to four anatomical landmarks were measured using a Vernier caliper with an accuracy of 0.1 mm.Results: The sphenoparietal type of pterion was the most common (83.8% left, 81.1% right), followed by the frontotemporal (8.1% left, 13.5% right), and epipteric (8.1% left, 2.7% right) types and the stellate type was the least commonly observed (2.7% left side only). The distances on the left and right sides respectively from the center of the pterion to the frontozygomatic suture were 3.60 ± 0.57 cm and 3.68 ± 0.50 cm, to the zygomatic arch 3.76 ± 0.39 cm and 4.03 ± 0.40 cm, to the tip of the mastoid process 7.96 ± 0.58 cm and 8.16 ± 0.61 cm, and to the topmost part of the external auditory meatus 5.42 ± 0.34 cm and 5.53 ± 0.35 cm.Conclusions: This knowledge is essential in surgical approaches and interventions via the pterion, especially for neurosurgeons while drilling a burr hole at the pterion to prevent orbital penetration due to an anterior drilling and an ineffective access for instrumentation due to a posterior drilling. It will also be helpful for surgeons, radiologists, anthropologists, forensic pathologists in their diagnosis and treatment.

A New Surgical Option For Patients with Unresolved Bell's Palsy.

This paper describes a new surgical procedure with electrical stimulation of the facial nerve for unresolved Bell's palsy and compares the facial nerve recovery with another group who underwent traditional middle cranial fossa decompression. All patients with total unilateral facial paralysis had surgery by the senior author 3months from onset of Bell's Palsy. Surgical decompression was performed in 13 patients between 1992-2012 (Group 1). Surgical exposure with intraoperative electrical stimulation of the facial nerve in the peri-geniculate region was performed in 47 patients between 2012-2022 (Group 2). The facial recovery at 1month and 3month were significantly better in Group 2. The degree of synkinesis was significantly less in Group 2. The trans-mastoid electrical stimulation of the facial nerve is less invasive, requires no hospital stay, and less time off work compared to the middle cranial fossa approach. The earlier facial movement at one month results in less long-term unwanted faulty regeneration or synkinesis.

Biportal Endoscopic TransOrbital and transMaxillary Approach to the Cranio-Orbital Region and Middle Cranial Fossa: A Preliminary Analysis of Maneuverability.

Traditional and well-established transcranial approaches to the spheno-orbital region and middle cranial fossa guarantee optimal intracranial exposure, and additional orbital and zygomatic osteotomies provide further control over extracranial components to be resected; however, these techniques come at the cost of additional morbidity. The introduction of minimally invasive endoscopic approaches and the conceptualization of the so-called "multiportal" paradigm might provide an alternative route. This preliminary study investigates the feasibility of the combined Biportal Endoscopic TransOrbital and transMaxillary Approach (bETOMA) approach to the spheno-orbital and middle cranial fossa regions. Using 4 silicon-injected adult cadaver heads (8 sides; 16 approaches), we systematically dissected through superior eyelid ETOA and endoscopic TMA approaches. The analysis focused on pterygopalatine, infratemporal, anterior and middle cranial fossae, Meckel cave, and cavernous sinus access. We evaluated the feasibility of bETOMA using linear distances, angles of attack, and exposure areas. We also introduced volume of operative maneuverability, its standardized derivative (sVOM), target distance, visuo-operative angle, and working zone volume as novel metrics. The analysis revealed comparable angles of attack between approaches. ETOA and TMA exposure areas were 918.38 ± 223.93 mm2 and 257.07 ± 86.07 mm2, respectively. TMA showed a larger VOM in the greater sphenoid wing, but ETOA offered superior distal maneuverability (sVOM: 5.39 ± 1.94 vs 2.54 ± 0.79 cm3) and closer intracranial space access (27.45 vs 50.83 mm). The combined approaches yielded a mean working zone volume of 13.75 ± 3.73 cm3 in the spheno-orbital interface. The bETOMA approach provides adequate neurovascular exposure and maneuverability to the spheno-orbital region, infratemporal, and anterior and middle cranial fossae, addressing significant limitations of previously investigated monoportal techniques (ie, optic nerve decompression, hyperostotic bone resection, and infratemporal exposure). This combined minimally invasive approach might help manage lesions harbored within the cranio-orbital interface region invading the extracranial space.

Exploring optimal microscopic keyhole access to the skull base: an anatomical evaluation of transciliary supraorbital and transpalpebral orbitofrontal craniotomy approaches

Purpose: The past two decades have witnessed the rise of keyhole microscopic minimally invasive surgeries, including the transciliary supraorbital approach (TCA) and transpalpebral approach (TPA), commonly known as the transorbital approach. This study aims to elucidate the nuances, specific indications, and advantages of each approach. Methods: A series of dissections were conducted on five formalin-fixed, alcohol-preserved cadaver heads. The TCA was performed on one side, and the TPA on the other. Virtual measurements of working angles for both approaches were recorded. Additionally, three clinical cases were presented to illustrate the practical application of the techniques. Results: For TCA, the craniotomy dimensions were 1.7 cm x 2.5 cm (Cranial-Caudal (CC) x Lateral-Lateral (LL)), while for TPA, they measured 2.1 cm x 2.9 cm (CC x LL). The measurements of anterior clinoid processes (ACP) were obtained and compared between approaches. In the TCA, the mean ipsilateral ACP measurement was 62 mm (Range: 61 –63 mm), and the mean contralateral ACP measurement was 71.2 mm (Range: 70 –72 mm). In TPA, these measurements were 47.8 mm (Range: 47 –49 mm) and 62.8 mm (Range: 62 –64 mm), respectively. TCA exhibited an average cranial-caudal angle of 14.9°, while TPA demonstrated an average of 8.3°. Conclusion: The anterior cranial fossa was better exposed by a TCA, which also featured shorter operative times, enhanced midline visualization, and a quicker learning curve. Conversely, the middle fossa was better exposed by a TPA, making it an excellent option for middle fossa pathologies, including those in the anterior temporal lobe. After sphenoid bone wing drilling, the TPA offers superior visualization from the lateral to the medial aspect and enhances the CC angle. Additionally, the TPA reduces the risk of postoperative frontalis palsy based on anatomic landmarks. However, the TPA requires a greater cranial osteotomy, and due to unfamiliarity with eyelid anatomy, the learning curve for most neurosurgeons is lengthier for this procedure.

SupraPetrous InfraTemporal Approach: A Supplemental Approach to Supracerebellar Infratentorial for Inferior Amygdala and Hippocampal Head Access-A Cadaveric Study With Case Illustrations.

Access to the amygdala and hippocampus (A/H) is complex. To address the limitations and invasiveness of traditional approaches, including the Transsylvian, Subtemporal, and Supracerebellar infratentorial approaches, we developed the suprapetrous infratemporal (SPIT) approach. This study describes the nuances of this approach in both cadaveric studies and clinical cases. Three unilateral exposures were performed using microscopic and endoscopic methodologies in the SPIT approach. After cadaveric investigation, this approach was successfully implemented in representative clinical cases. The SPIT approach enabled direct access to the inferior A/H, circumventing the requirement for temporal lobe retraction and detachment of the temporal lobe from the dura through a subtemporal route by drilling the upper part of the mastoid, consequently mitigating tension on the vein of Labbé. This enabled a bottom-up view because one would gain with a zygomatic osteotomy and forward projection like a mini-posterior petrosal view by using a transmastoid view, without cutting down the zygomatic arch and opening the dura subtemporally, limiting patient pain and preventing case comorbidity. The SPIT approach was performed in 2 cases of mesial temporal cavernoma presenting with seizures. The lesion was visualized intraoperatively and was successfully removed in these cases. The postoperative course was excellent with no complications, and gross total resection was radiographically confirmed with Engel Class 1a seizure freedom. The SPIT approach is a complementary approach for inferior A/H disease, combining the combined middle fossa approach modified for intradural pathology. Limited drilling of the upper aspect of the mastoid with a medial dural opening at the level of the arcuate eminence provides a direct trajectory with minimal brain retraction. Additional research encompassing a larger patient cohort and extended follow-up periods is required to substantiate the advantages of SPIT in the management of inferior A/H lesions.

Predictors of operative ischemic cerebrovascular complications in skull base tumor resections: Experience in low-resource setting

Abstract Background Ischemic cerebrovascular complications following skull base tumor resections remain a significant factor impacting both short-term and long-term patient outcomes. This study aims to improve risk stratification, surgical decision-making, and postoperative care protocols. Methods A retrospective cohort study on predictors of ischemic cerebrovascular complications among patients who underwent skull base tumor resection was conducted at 2 high-volume neurosurgical centers in Ethiopia from 2018 to 2023. Binary logistic analysis was performed to see the association of each predictor variable. Results The study included 266 patients, with 65.5% being female. The median age and tumor size were 37 (± IQR = 17) years and 4.9 cm (± IQR 1.5), respectively. Ischemic cerebrovascular complications occurred in 19.9% of patients. Middle cranial fossa tumors and tumors spanning both anterior and middle cranial fossa (AOR = 6.75, 95% CI: 1.66–27.54, P &amp;lt; .008), grades 3–5 vascular encasement (AOR = 5.04, 95% CI: 1.79–14.12, P &amp;lt; .002), near-total resection and gross total resection (AOR = 2.89, 95% CI: 1.01–8.24, P &amp;lt; .048), and difficult hemostasis (AOR = 9.37, 95% CI: 3.19–27.52, P &amp;lt; .000) were significantly associated with iatrogenic vascular injury. Subarachnoid hemorrhage had a statistically significant association with vasospasm (AOR = 12.27, 95% CI: 1.99–75.37, P = .007). Conclusions Surgery-related ischemic cerebrovascular complications are common. Thorough perioperative risk stratification and proactive treatment planning are crucial to mitigate vascular insults associated with it. In low-resource settings, neurosurgical services are provided without advanced instruments, leading to more complications. Therefore, it is important to focus on improving neurosurgical setup to enhance patient outcomes.

MORPHOMETRIC VARIATION OF FORAMEN OVALE IN DRY ADULT SKULL OF INDIAN POPULATION WITH CLINICAL CORRELATIONS

Objective: The present study aim is to evaluate morphology and morphometric measurements of foramen Ovale present in the Greater wing of Sphenoid bone of the Middle Cranial fossa of the Skull base, using Digital sliding Vernier caliper. The anatomical knowledge of Foramen Ovale and it’s variations are of great help to neurosurgeons, oncologists and radiologists while performing any diagnostic and surgical interventions into and nearby foramen to deal with unavoidable complications as Tic douloureux. Methods: This study was done in 35 dried Human skulls taken from the Department of Anatomy, GBCM, Dehradun, India. The length and the width of the Foramen Ovale were measured. The different shapes of the foramen were also seen. All data collected was subjected to Statistical analysis using Student’s T-test. Results: In the present study, Incidence of Oval shape foramen Ovale was maximum, followed by Elongated shape. There were no statistical differences between the mean length and mean width on the two sides of Foramen Ovale. Conclusion: The vast knowledge of different shapes and sizes of foramen Ovale to Neurosurgeons and Oncologists helps to operate with least invasive procedures to avoid clinical manifestations.