Diagnostic accuracy of intrathecal fluorescein versus other radiological modalities in evaluating non-congenital skull base defects: a systematic review and meta-analysis.

PURPOSE: The intraoperative detection of cerebrospinal fluid (CSF) leaks during endoscopic skull base surgery is critical to ensure watertight sealed defects. Intrathecal fluorescein (ITF) is a valuable adjunct to intraoperative investigation. Hence, our aim is to summarize the evidence of the efficacy of ITF as an accurate diagnostic modality and reconstruction guide for non-congenital skull base defects. METHODS: Using the Cochrane Central, MEDLINE, and Embase databases, we identified studies involving the use of ITF in non-congenital CSF leaks which were published until November 2023. The STATA 18 software was used for meta-analysis. RESULTS: Fourteen studies met the inclusion criteria, in which seven studies were included in the meta-analysis. ITF was used in 1898 (90.3%) of patients, with a detection rate of 88.1%. The overall detection rate of non-congenital CSF leaks among ITF concentrations of 5% and 10% had a statistically significant pooled effect size of 2.6 (95% CI = 2.25, 2.95), while when comparing the ITF to other alternative radiological tests, it was not statistically significant with a mean difference of 0.88 (95% CI = - 0.4, 2.16). Moreover, the pooled prevalence was statistically significant in regards of the complications associated with ITF with an effect size of 0.6 (95% CI = 0.39, 0.82), indicating that 60% of patients who underwent ITF would experience at least one of the measured complications. CONCLUSION: ITF is considered as an efficient tool in localizing skull base defects. However, there was no significant results when comparing the ITF to other alternative radiological tests. Accordingly, if the ITF intervention is indicated, patients should be carefully selected based on their clinical need.

A Safe Technique for Excising the Perpendicular Plate of the Ethmoid Bone in Patients with Crooked Nose: A Finite Element Analysis.

BACKGROUND: Correction of the crooked nose, especially the perpendicular plate of the ethmoid bone, has the potential to cause skull base injury. At present, the safe and effective method for perpendicular plate resection has not been clearly defined through biomechanics. METHOD: CT scan data of 48 patients with crooked nose and deviated nasal septum were divided into C-type, angular deformity-type, and S-type based on the morphology of the 3D model. Different types of finite element models of the nasal bony septum and skull base were established. The osteotomy depth, angle, and force mode of the PPE resection were simulated by assembling different working conditions for the models. The von Mises stress of the anterior cranial fossa was observed. RESULTS: When the osteotomy line length was 0.5 cm, the angle was at 30° to the Frankfurt plane, and 50 N·mm torque was applied, the von Mises stress of the skull base was minimal in the four models, showing 0.049 MPa (C-type), 0.082 MPa (S-type), 0.128 MPa (angular deformity-type), and 0.021 MPa (control model). The maximum von Mises stress values were found at the skull base when the osteotomy line was 1.5 cm, the angle was 50°, and the force was 10 N along the X-axis, showing 0.349 MPa (C-type), 0.698 MPa (S-type), 0.451 MPa (angular deformity-type), and 0.149 MPa (control model). CONCLUSION: The use of smaller resection angle with the Frankfurt plane, conservative resection depth, and torsion force can better reduce the stress value at the skull base and reduce the risk of basicranial fracture. It is a safe and effective technique for perpendicular plate resection of the ethmoid bone in the correction of crooked nose. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Spontaneous rhinorrhea and idiopathic intracranial hypertension: a complex and challenging association.

INTRODUCTION: Spontaneous CSF leak is a known complication of idiopathic intracranial hypertension (IIH). Patients with CSF rhinorrhea present a unique challenge within the IIH population, as the occurrence of a leak can mask the typical IIH symptoms and signs, complicating the diagnosis. Treatment of leaks in this population can also be challenging, with the risk of rhinorrhea recurrence if intracranial hypertension is not adequately treated. OBJECTIVE: The aim of this narrative review was to examine current literature on the association between spontaneous CSF rhinorrhea leaks and IIH, focusing on key clinical features, diagnostic approaches, management strategies, and outcomes. MATERIAL AND METHODS: A literature search was executed using the PubMed and Scopus databases. The search was confined to articles published between January 1985 and August 2023; extracted data was then analysed to form the foundation of the narrative review. RESULTS: This search yielded 26 articles, comprising 943 patients. Average age was 46.8 ± 6.5 years, and average body mass index was 35.8 ± 4.8. Most of the patients were female (74.33%). Presenting symptoms were rhinorrhea, headaches and meningitis. The most common imaging findings were empty sella and encephalocele. The standard treatment approach was endoscopic endonasal approach for correction of CSF rhinorrhea leak, and shunt placement was also performed in 128 (13%) patients. Recurrences were observed in 10% of cases. CONCLUSIONS: The complex relationship between spontaneous CSF leaks and IIH is a challenge that benefits from multidisciplinary evaluation and management for successful treatment. Treatments such as endoscopic repair, acetazolamide, and VP/ /LP shunts reduce complications and recurrence. Personalised plans addressing elevated intracranial pressure are crucial for successful outcomes.

How I do it? Endoscopic endonasal transpterygoid repair of sphenoid lateral recess cerebrospinal fluid leak after previous unsuccessful transcranial surgery.

BACKGROUND: Direct access to the sphenoid lateral recess offers the best chance of sealing spontaneous cerebrospinal fluid (CSF) rhinorrhea caused by lateral sphenoid encephaloceles of the Sternberg canal defect. METHOD: We present a case of spontaneous left-sided sphenoid lateral recess CSF leak after previous unsuccessful transcranial surgery managed with an endoscopic endonasal transpterygoid approach (EETA). An anatomical-based step-by-step illustration of the EETA was presented in the surgical video. CONCLUSION: This case demonstrates the value of endoscopic endonasal transpterygoid corridor in the exposure and manipulation of the sphenoid lateral recess.

Spontaneous cerebrospinal fluid rhinorrhea associated with an incidental pituitary adenoma.

Spontaneous cerebrospinal fluid (CSF) rhinorrhea presenting as the sole symptom of untreated pituitary adenoma is rare, with only 15 cases having been reported in the English literature. All these untreated pituitary adenoma contributing to spontaneous CSF rhinorrhea were diagnosed by the preoperative neuroimaging. Herein, we described an extraordinary rare patient with a pituitary microadenoma, presenting with spontaneous CSF rhinorrhea as the sole symptom. However, this pituitary microadenoma was only found incidentally at surgery, not preoperatively. To the best knowledge of us, this is the first reported case of spontaneous CSF rhinorrhea associated with an untreated pituitary adenoma diagnosed at surgery.

Correlation between Pneumatization Variants of Paranasal Sinuses and Skull Base and Spontaneous Cerebrospinal Fluid Rhinorrhea: A Case-Control Study.

INTRODUCTION: Spontaneous cerebrospinal fluid rhinorrhea (SCSFR) is the most common type of cerebrospinal fluid leakage and may cause serious cerebral complications. The aim of this research was to investigate the relationship between the degree of pneumatization variants of the paranasal sinus and skull base and the incidence of SCSFR. METHODS: In total, 131 patients with SCSFR were analyzed, and 50 patients suffering from the nasal septal deviation were selected as controls. The pneumatization of the paranasal sinus and skull base was observed by CT scan. RESULTS: Among the 137 fistulas, 55 (40.15%) were found in the ethmoid sinus. The incidences of Onodi cells (27.27 vs. 8%) and type 3 lateral recess of the sphenoid sinus (LRSS, 70.37 vs. 22%) in the SCSFR subgroups were significantly higher than those in the control group (p < 0.05). Moreover, the occurrence of SCSFR was linearly correlated with the classification of Onodi cells and LRSS (p < 0.05). There was no significant difference in the incidence of frontal cells, anterior clinoid process pneumatization, and posterior clinoid process pneumatization between the SCSFR patients and the controls. CONCLUSION: The most common site of SCSFR is the ethmoid sinus. The excessive pneumatization of the Onodi cell and LRSS increases the risk for the occurrence of SCSFR in the ethmoid sinus and sphenoid sinus, respectively. The possible association between the paranasal sinus ontogeny and SCSFR pathophysiology needs further studies.

Cerebrospinal fluid rhinorrhea from the lateral recess of sphenoid sinus: More to it than meets the eye.

BACKGROUND: Cerebrospinal fluid (CSF) leak from the lateral recess of the sphenoid sinus is rare when compared to leaks from other sites. The extended endonasal approach along with a transpterygoid extension provides adequate exposure for repair of these defects. MATERIALS AND METHODS: We retrospectively analyzed a series of seven patients who underwent eight transpterygoid approaches for repair of the CSF leak from the lateral recess of the sphenoid sinus. We analyzed the patient characteristics, site of leaks, type of repair done, and presence of increased intracranial pressure (ICP) in these individuals. RESULTS: Seven patients underwent eight transpterygoid approaches for CSF leaks from the lateral recess of the sphenoid sinus. The leak was bilateral in one patient. The materials used for repair consisted of fat, fascia lata, free mucosal flap or a vascularised nasoseptal flap, and fibrin glue. Evidence of increased ICP was found in five of the seven patients. CSF diversion was needed in three of the seven patients (two ventriculoperitoneal shunt and one thecoperitoneal shunt). CONCLUSION: Endoscopic endonasal transpterygoid approach provides an excellent visualization of the skull-base defect and facilitates adequate instrument manipulation within the corridor, allowing successful repair of the defect with low rates of recurrence. Increased ICP can have a role in causing spontaneous CSF rhinorrhea from this location.

Spontaneous cerebrospinal fluid leaks in the anterior skull base secondary to idiopathic intracranial hypertension.

Spontaneous cerebrospinal fluid (CSF) leaks represent a clinical entity in which CSF rhinorrhea occurs in the absence of any inciting event. Spontaneous CSF leaks are associated with elevated intracranial pressure (ICP) or have underlying idiopathic intracranial hypertension (IIH). We report a cohort of patients who have undergone nasal endoscopic repair for spontaneous CSF leaks. We review our perioperative complications and the effectiveness of the nasal endoscopic approach to repair spontaneous CSF leaks. Also, we examine the evidence correlating spontaneous CSF leaks and IIH and the role of decreasing ICP in the treatment of nasal spontaneous CSF leaks. A retrospective analysis of patients with nasal spontaneous cerebrospinal fluid leaks was performed. Data on the nature of presentation, patient body mass index, defect location and size, ICP, clinical follow-up, and complications were collected. Thirty-five patients had nasal spontaneous cerebrospinal fluid leaks with evidence of IIH's symptoms. The most common sites were the cribriform plate, the ethmoid roof, and sphenoid lateral pterygoid recess. All patients underwent endonasal endoscopic surgery to repair the defect. Postoperatively, all patients underwent lumbar drainage and acetazolamide therapy. Nasal spontaneous cerebrospinal fluid leaks represent a surgical challenge because of their high recurrence rates. The most important factor for obtaining a successful repair in these patients is reducing their intracranial pressure through nutritional, medical, or surgical means.

Isolated sphenoid sinus pathologies: a series of 40 cases

Background/aim: Isolated sphenoid sinus-derived lesions are rare and generally present with unclear symptoms. We are sharing our experience to be mindful of such lesions in differential diagnosis and to help accomplish successful treatment while avoiding revisions and complications.Materials and methods: Data from patients who underwent isolated sphenoid sinus surgeries (ISSs) were retrospectively extracted from the period of January 2005 to August 2015. Demographic data, chief complaints and presenting symptoms, imaging findings, surgical management, and results were evaluated. Results: There were 40 patients who underwent ISS. These patients had different pathologies. The chief complaint was nonspecific headache, except for cerebrospinal fluid leak patients who presented with serous rhinorrhea. Conclusion: It is critical to investigate suspicious symptoms with clinical findings and imaging techniques to avoid late diagnoses of isolated sphenoid pathologies. The transnasal approach is more minimally invasive and tissue-sparing. In our experience, we have noted that excising the inferior one-third of the superior turbinate decreases revisions. On the other hand, results show that the presence of concomitant pathology and invasive fungal disease increases the risk of revision surgery and complications.

[Cerebrospinal fluid rhinorrhea in primary treatment of large and giant prolactinomas with dopamine agonists]. / Nazal'naia likvoreia pri pervichnom lechenii bol'shikh i gigantskikh prolaktinom agonistami dofamina.

At present, pharmacological therapy of prolactinomas with dopamine agonists (DAs) is considered the treatment of choice. In most cases, giant prolactinomas respond to treatment with dopamine agonists and decrease in size during the first months of the treatment. One of the rare but dangerous complications of conservative treatment of prolactinomas with invasive growth is cerebrospinal fluid rhinorrhea. MATERIAL AND METHODS: We present a retrospective analysis of 15 patients with macropropactinomas who underwent surgery for cerebrospinal fluid rhinorrhea developed due to primary therapy with dopamine agonists at the Burdenko Neurosurgical Institute (BNI) in the period between 2005 and 2015. All patients had large and giant tumors (according to the classification adopted at the BNI). When cerebrospinal fluid rhinorrhea was detected, patients were hospitalized to the BNI for examination, detection of a CSF fistula, reconstruction of a defect, and resection (if possible) of the tumor. RESULTS: In the period between 2005 and 2015, 15 patients (8 males and 7 females) with prolactinomas of a large and giant size at the onset of conservative therapy underwent surgery for cerebrospinal fluid rhinorrhea at the BNI. All patients underwent transnasal reconstruction of a skull base defect, with 13 out of 15 patients undergoing simultaneous resection of the tumor. After tumor resection, reconstruction was performed using auto-fat, fascia, and glue (in 8 cases). In the remaining cases, apart from auto-fat, fascia, and glue, a mucoperiosteal flap and auto-bone were used. Fourteen patients were followe-up. In 13 cases, there was no relapse of cerebrospinal fluid rhinorrhea after skull base reconstruction. In 1 case, there was a relapse of cerebrospinal fluid rhinorrhea. CONCLUSION: Conservative treatment of patients with giant prolactinomas should be performed under regular control of ENT doctors and neurosurgeons for timely detection and surgical treatment of cerebrospinal fluid rhinorrhea.

Non-Invasive and Minimally Invasive Imaging Evaluation of CSF Rhinorrhoea - a Retrospective Study with Review of Literature.

BACKGROUND: Localization of a cerebrospinal fluid [CSF] fistula is a diagnostic challenge. The choice of an optimal imaging technique is necessary to locate the site of CSF leak which is required for surgical/endoscopic repair of the CSF fistula. MATERIAL/METHODS: Retrospective analysis of imaging was performed in 33 patients who presented with symptoms suggestive of CSF rhinorrhoea over a period of two years. Either a bone defect on high resolution CT [HRCT] or CSF column extending extracranially from the subarachnoid space with or without brain/ meningeal herniation on magnetic resonance [MR] cisternography was considered positive for CSF leak. The MR imaging technique included 1-mm heavily T2-weighted [TR 2000 ms; TE-200 ms] fast spin echo study in coronal and sagittal planes. HRCT sections involved 0.625 to 0.8-mm sections in the coronal plane, with or without axial planes, through the paranasal sinuses, reconstructed in a sharp algorithm and acquired with the patient in prone position. Imaging findings were compared with endoscopic findings, being the gold standard for the assessment of CSF rhinorrhea. RESULTS: A total of 25 patients had a combination of HRCT and MR cisternography. The sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV] of both MR cisternography and HRCT together were 93%, 100%, 100% and 50% respectively. Two patients underwent only MR cisternography, 5 patients underwent only HRCT and one patient underwent HRCT, MR cisternography and CT cisternography. Though PPV was 100% in the groups with HRCT alone, MR cisternography alone and combined CT cisternography, HRCT and MR cisternography, the results were not statistically significant as the number of patients in those groups was lower. CONCLUSIONS: Combination of MR cisternography and HRCT appears to be complementary, accurate and non-invasive and should be considered as optimal imaging modality for pre-op imaging in the evaluation of CSF rhinorrhoea.

Role of Acetazolamide in Traumatic CSF Rhinorrhea and Otorrhea: A Randomized Controlled Trial.

Background Untreated cerebrospinal fluid (CSF) rhinorrhea and otorrhea can lead to adverse complications like meningitis and hence should not be overlooked. Acetazolamide reduces CSF production by 48%. The actual role of acetazolamide in the amelioration of traumatic CSF rhinorrhea and otorrhea is not clear as, till date, very few formal studies have been conducted. Aim of the study was to determine the role of acetazolamide in traumatic cerebrospinal fluid rhinorrhea and otorrhea. Materials and Methods A randomized controlled trial was conducted among 134 patients with head injuries presenting to the neurosurgery department of a tertiary care center in North India, with complaints of CSF rhinorrhea and otorrhea within 72 hours of traumatic injury. One-hundred thirty-four patients were randomized into intervention and control group. Comparative analysis was not possible in 58 patients as in due course they were either operated for head injury or lumbar drain was put due to excessive CSF leak; hence, forth comparative analysis was done in 76 patients. Out of these 76 patients, 44 patients belonged to the intervention group (Acetazolamide given) and 32 belong to the control group (Acetazolamide not given). The day of the stoppage of CSF Leak was the main endpoint of this study. Result Majority of the patients were in the age group of 21 to 30 years and were predominantly males. Road traffic accident was observed in 84 (75%) patients. There was no statistically significant difference noted in the mean number of days of CSF leak whether acetazolamide was given or not ( p = 0.344). The complication associated with CSF leak was meningitis. The percentage of patients developing meningitis was more after lumber drain insertion. Conclusion In our study, there was no advantage of adding acetazolamide to the conservative management of traumatic CSF leak. Therefore, the practice of routinely giving acetazolamide should be reconsidered.

3D Slicer reconstruction combined with neuroendoscopic keyhole approach for the treatment of cerebrospinal fluid rhinorrhea：2 cases report and literature review.

Background and importance: Explore the techniques, advantages and disadvantages of 3D Slicer reconstruction combined with transcranial neuroendoscopy in cerebrospinal fluid rhinorrhea surgery. Clinical presentation: We collected complete clinical data of two patients with cerebrospinal fluid rhinorrhea who underwent minimally invasive surgery using 3D Slicer reconstruction combined with transcranial neuroendoscopy through the supraorbital eyebrow arch keyhole approach in our hospital from June 2022 to May 2023. The patients were one male and one female, aged 50 and 63 years old. At the same time, a retrospective summary of relevant literature at home and abroad in recent years was conducted. 1 case had spontaneous cerebrospinal fluid rhinorrhea with secondary cribriform plate lesion, and the other 1 case had traumatic cerebrospinal fluid rhinorrhea. Both 2 patients were ineffective after long-term conservative treatment, and ultimately recovered after detailed preoperative evaluation and preparation and surgical treatment. Conclusion: Cerebrospinal fluid rhinorrhea is a challenging disease in neurosurgery, and improper management can lead to serious complications such as meningitis. Our team used 3D Slicer reconstruction combined with transcranial endoscopic minimally invasive keyhole surgery to treat cerebrospinal fluid rhinorrhea, achieving good results, proving that this combined technology has certain advantages and is a new surgical technique worth promoting. However, the widespread application and promotion of this technology in anterior skull base surgery still require comprehensive and reliable prospective clinical studies to test.

Management of cerebrospinal fluid rhinorrhea as a rare complication of antiphospholipid syndrome.

Background: Antiphospholipid syndrome is a complex autoimmune condition associated with the formation of recurrent thrombosis in any vascular bed throughout the body. Jugular vein thrombosis is very rare with only a 0.9% occurrence and is not typically associated with cerebrospinal rhinorrhea as a result of raised intracranial pressure. Case Description: A 54-year-old patient presented with a 9-month history of cerebrospinal fluid (CSF) rhinorrhea and headache on a background of antiphospholipid syndrome. Investigations showed a superior vena cava (SVC) and right internal jugular vein (IJV) obstruction with moderately elevated intracranial venous pressures. Her magnetic resonance imaging (MRI) brain was consistent with a CSF leak. The patient underwent successful endovascular stenting of her obstructed SVC and right IJV followed by surgical repair of a herniating meningocele in the posterior left ethmoid air cells. Conclusion: CSF rhinorrhea is uncommon and never previously reported associated with SVC thrombosis induced by antiphospholipid syndrome. A combination of endovascular techniques and surgical repair is recommended for this challenging presentation.

Spontaneous Cerebrospinal Fluid Rhinorrhea With Meningoencephalocele Recurrence After Placement of a Lumboperitoneal Shunt: A Case Report.

Cerebrospinal fluid rhinorrhea associated with meningoencephalocele is usually treated surgically. During the perioperative period, cerebrospinal fluid diversion may be employed to control intracranial pressure, but there are few indications for this method. A 51-year-old female presented with cerebrospinal fluid rhinorrhea associated with meningoencephalocele and underwent surgical repair followed by the placement of a lumboperitoneal shunt. However, cerebrospinal fluid leakage recurred, requiring a second surgery. Lumbar drainage effectively controls intracranial pressure, but it does not cure bone defects. The use of these devices should be carefully considered based on the patient's condition.

Management of frontoethmoidal osteoma causing pneumocephalus and cerebrospinal fluid leakage with minimally invasive techniques: illustrative cases.

BACKGROUND: Osteoid osteoma is a common benign bone tumor frequently seen in the frontoethmoid region. However, involvement of the skull base is rare, with few cases previously reported. OBSERVATIONS: The authors report two cases of spontaneous, symptomatic frontoethmoidal osteoma: one presented with neurological deficit secondary to tension pneumocephalus and the other with cerebrospinal fluid leakage. The first case was managed with a transfrontal sinus craniotomy and pneumocephalus decompression with osteoma resection and skull base reconstruction. The second case was managed with a uninaral endoscopic endonasal approach to the anterior skull base with osteoma resection and reconstruction. LESSONS: Given the paucity of cases with associated tension pneumocephalus described in the literature, it was relevant to describe the authors' experience with surgical decision-making and the expected outcomes among patients with this pathology when using minimally invasive techniques.

Management of Recurrent Cerebrospinal Fluid Rhinorrhea Caused by Sequential, Anatomically Separated Skull Base Defects-A Case-Based Systematic Review.

OBJECTIVE: Recurrent cerebrospinal fluid (CSF) rhinorrhea caused by sequential, anatomically separated skull base defects is rarely reported in the literature. Neither management nor etiology has been sufficiently investigated. We present an illustrative case and a systematic review of the literature regarding etiology, diagnostics, and management of this rare phenomenon. METHODS: A systematic literature search looking for articles reporting sequential CSF leaks with multiple skull base defects was performed. Data from included articles were descriptively reported, and the quality of the included studies was assessed with Grading of Recommendations Assessment, Development and Evaluation. RESULTS: A 71-year-old woman with posttraumatic CSF rhinorrhea and left-sided CSF otorrhea due to a left-sided horizontal fracture of the petrous bone presented at our institution. After initial surgical repair and a 10-week symptom-free interval, CSF rhinorrhea recurred. Imaging revealed a preexisting contralateral meningoencephalocele of the lateral sphenoid recess causing recurrent CSF rhinorrhea most likely after initial traumatic laceration. The defect was successfully treated. A literature search identified 366 reports, 6 of which were included in the systematic review with a total of 10 cases. Quality was deemed good in 8 of 10 cases. The most common location for primary and sequential CSF leaks was along the sphenoid bone (4/10 and 5/10 patients, respectively). All publications except one reported the presence of a meningo (encephalo)cele as cause of the sequential CSF leak. CONCLUSIONS: Occurrence of recurrent CSF rhinorrhea due to an anatomically separated sequential skull base lesion remains a rare phenomenon. Reassessment of imaging studies and a structured diagnostic workup to detect sequential CSF leaks independent of the primary lesion should is recommended.

Endoscopic Management of a Case of Spontaneous Cerebrospinal Fluid Leaks in Anterior Skull Base.

Spontaneous cerebrospinal fluid (sCSF) leaks are rare, and their diagnosis and treatment often present significant challenges. This paper discusses and reports cases experienced at our facility. We retrospectively reviewed three of five cases of sCSF leaks experienced at the Department of Otolaryngology and Head and Neck Surgery, Kyushu University, from December 2020 to December 2022, excluding CSF otorrhea. All three patients were female; their mean age was 56 years (44-71 years). Two of the three patients were obese (first degree), and one was average weight (according to the criteria of the Japan Society for the Study of Obesity). Two patients had hypertension, and one had sleep apnea syndrome as an underlying disease. In all cases, leakage sites, which were all the cribriform plate, can be endoscopically identified, and all could be closed by an endoscopic intranasal approach. We reviewed cases of sCSF leaks. Although some patients had difficulty identifying the leakage site in a narrow and complex nasal cavity, an endoscopic survey was useful in identifying the leakage site. All cases were closed and there were no signs of recurrence. Identifying the site of leakage and selecting the appropriate closure method depending on the extent of the leakage is essential in treating such cases.

Reliability of High-resolution Gadolinium-enhanced MR Cisternography and Gasket-seal Technique for Management of Anterior Skull Base Defects.

PURPOSE: Precise preoperative localization of anterior skull base defects is important to plan surgical access, increase the success rate and reduce complications. A stable closure of the defect is vital to prevent recurrence of cerebrospinal fluid (CSF) rhinorrhea. The purpose of this retrospective case series was to evaluate the reliability of a new high-resolution gadolinium-enhanced compressed-sensing SPACE technique (CS T1 SPACE) for magnetic resonance (MR) cisternography to detect cerebrospinal fluid leaks of the anterior skull base and to assess the long-term success rate of the gasket-seal technique for closure of skull base defects. METHOD: All patients with spontaneous or postoperative cerebrospinal fluid rhinorrhea and defects of the anterior skull base presenting to the Departments of Otorhinolaryngology and Neurosurgery between 2019 and 2020, receiving a computed tomography (CT) cisternography and MR cisternography (on a 3T whole-body MR scanner using a 64-channel head and neck coil) with CS T1 SPACE sequence and closure of the defect with the gasket-seal technique, were enrolled in the study. For the cisternography, iodinated contrast agent (15 ml Solutrast 250 M®), saline (4 mL) mixed with a 0.5 mL of gadoteridol was injected into the lumbar subarachnoid space. RESULTS: A total of four patients were included in the study and MR cisternography with CS T1 SPACE sequence was able to precisely localize CSF leaks in all patients. The imaging results correlated with intraoperative findings. All defects could be successfully closed with the gasket-seal technique. The mean follow-up was 35.25 months (range 33-37 months). CONCLUSION: MR cisternography with CS T1 SPACE sequence could be a promising technique for precise localization of CSF leaks and the gasket-seal technique resulted in good closure of the CSF fistula in this case series.

Clinical application of transcranial neuroendoscopy combined with supraorbital keyhole approach in minimally invasive surgery of the anterior skull base.

To explore the techniques, safety, and feasibility of minimally invasive neurosurgery through the supraorbital eyebrow arch keyhole approach by neuroendoscopy. Retrospective analysis of clinical data of patients with various cranial diseases treated by transcranial neuroendoscopic supraorbital eyebrow keyhole approach in our hospital from March 2021 to October 2023. A total of 39 complete cases were collected, including 21 cases of intracranial aneurysms, 9 cases of intracranial space occupying lesions, 5 cases of brain trauma, 3 cases of cerebrospinal fluid rhinorrhea, and 1 case of cerebral hemorrhage. All patients' surgeries were successful. The good prognosis rate of intracranial aneurysms was 17/21 (81%), and the symptom improvement rate of intracranial space occupying lesions was 8/9 (88.9%). Among them, the initial symptoms of one patient with no improvement were not related to space occupying, while the total effective rate of the other three types of patients was 9/9 (100%). The average length of the craniotomy bone window of the supraorbital eyebrow arch keyhole is 3.77 ± 0.31 cm, and the average width is 2.53 ± 0.23 cm. The average postoperative hospital stay was 14.77 ± 6.59 days. The average clearance rate of hematoma by neuroendoscopy is 95.00% ± 1.51%. Our results indicate that endoscopic surgery through the supraorbital eyebrow arch keyhole approach is safe and effective for the treatment of anterior skull base lesions and cerebral hemorrhage. However, this retrospective study is a single center, small sample study, and the good surgical results do not exclude the subjective screening of suitable patients by clinical surgeons, which may have some bias. Although the clinical characteristics such as indications and contraindications of this surgical method still require further prospective and multicenter clinical research validation, our study still provides a new approach and choice for minimally invasive surgical treatment of anterior skull base lesions.