Cerebrospinal fluid (CSF) rhinorrhea is one of the most common complications after trans-sphenoidal surgery. At present, transcranial or endoscopic surgery for CSF leakage requires general anesthesia to remove autologous fat or fascia to repair the leak, which is traumatic and costly. The authors present a case of a 25-year-old male patient with pituitary adenoma who experienced CSF rhinorrhea 10 days after undergoing endoscopic resection of the tumor. The authors innovatively sequential filled the leak with a gelatin sponge soaked in povidone-iodine solution and iodinated gauze under outpatient nasal endoscopy. The follow-up of 6 months showed no recurrence of CSF leakage. CSF leakage is the most common complication of trans-sphenoidal surgery. The authors suggest that for small cerebrospinal fluid leaks in the early stage after trans-sphenoidal surgery, the leakage should be first filled with gelatin sponge and iodoform gauze sequentially under outpatient nasal endoscopy, which may achieve a complete cure.

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.

The nasal skull base is located into the deep position of nasal cavity and closely related to important nerves and vessels. The complete removal of tumors in this area poses a complex surgical challenge.In order to investigate the clinical efficacy of utilizing free middle turbinate mucosa (FMT), fascia lata, and pedicled nasal septum flap (known as the Hadad-Bassagasteguy flap, HBF) for the treatment of cerebrospinal fluid (CSF) rhinorrhea, a retrospective analysis was conducted on clinical data from 65 patients who underwent skull base reconstruction following endoscopic resection of nasal-skull base tumors. The selection of the repair material was based on the size and location of the defect. For defects less than 1.5 cm (n = 24), FMT was chosen, while for defects greater than or equal to 1.5 cm (n = 16), HBF was preferred. In cases where HBF was not available or not suitable (specifically, when the defect was located on the posterior wall of the frontal sinus), fascia lata was selected (n = 25). The repair outcomes of all 65 patients were summarized, and subsequently, a comparison was made between the use of fascia lata and HBF. The overall success rate for one-time repairs was 93.8 %. Specifically, the success rates for repairs using FMT, fascia lata, and HBF were 91.7 %, 96.0 %, and 93.8 %, respectively. Throughout the follow-up period, there were 2 cases of postoperative CSF leakage out of 24 patients who underwent FMT reconstruction, 1 case out of 25 patients who underwent fascia lata reconstruction, and 1 case out of 16 patients who underwent HBF reconstruction. The occurrence of postoperative complications, such as intracranial infection, lung infection, and epistaxis, was observed in both the fascia lata group and the HBF group. However, there were no statistically significant differences between the two groups. The transnasal endoscopic reconstruction of skull base defect using HBF, fascia lata, and FMT demonstrated satisfactory repair effects in managing CSF rhinorrhea. Generally, FMT has been found to be a dependable repair material for small defects measuring less than 1.5 cm, while in the case of larger defects equal to or exceeding 1.5 cm, both HBF and fascia lata can be utilized with comparable repair outcomes. The selection of fascia lata becomes a viable option when HBF is unavailable or not suitable.

BACKGROUND: Aspiration pneumonitis (AP) secondary to cerebrospinal fluid (CSF) leak is underestimated and rarely discussed. This study aimed to evaluate the association between AP and CSF leaks.
METHODS: Clinical and surgical characteristics of CSF leak patients with and without AP between January 2010 and December 2022 were included and compared.
RESULTS: This study included 159 patients, 16 with CSF otorrhea and 143 with CSF rhinorrhea. Among them, 40 (25.2%) had AP. Bilateral pneumonitis was identified in 32 cases, of which 11 showed severe pneumonitis in the right upper lung lobe. Twenty-one (52.5%) asymptomatic and 19 (47.5%) symptomatic cases were documented. The major clinical manifestations included cough (n = 19, 47.5%) and expectoration (n = 9, 22.5%). The prevalence of pneumonitis was significantly higher in the spontaneous group than in the traumatic group. High-flow CSF leak was associated with AP (42.5% vs. 16.8%, p = 0.001). No significant differences were identified in defect locations between patients with and without AP. Patients with pneumonitis had a higher prevalence of meningitis (32.5% vs. 12.6%, p = 0.003). Multiple logistic regression results revealed that meningitis, spontaneous and high-flow CSF leaks are independent factors for AP occurrence. Both the CSF leak and pulmonary complications resolved following successful surgical repair.
CONCLUSIONS: AP secondary to CSF leaks is frequently underdiagnosed, with a higher incidence identified in spontaneous cases. The occurrence of AP was associated with high-flow CSF leak.
CONCLUSIONS: A pneumonitis rate of 25.2% in cerebrospinal fluid (CSF) leak patients was reported for the first time. A higher prevalence of aspiration pneumonitis was identified in spontaneous CSF leak. Meningitis, spontaneous and high-flow CSF leaks are independent factors for aspiration pneumonitis occurrence.

Cerebrospinal fluid rhinorrhea (CSFR) is a condition in which the cerebrospinal fluid flows out of the nasal cavity due to rupture of the arachnoid, dura, and nasal membranes because of bone defects in the skull base. The authors report a rare case of CSFR in a 2-year-old girl who experienced trauma in the nasal cavity by a bamboo stick. She underwent endoscopic repair for the CSFR. During surgery, a bulged vesicle was observed at the left cribriform plate with a small amount of cerebrospinal fluid draining from the surrounding area. Postoperative recovery was good. Endoscopic CSFR repair in pediatric patients is minimally invasive, effective, and safe as demonstrated in this case. Prevention of CSFR in children is important. Parents and caretakers of children need to be more aware, and potentially dangerous objects should not be kept within reach of children.

A 27-year-old female patient presented with chronic spontaneous cerebrospinal fluid (CSF) rhinorrhea. She had deformity and weakness on the left side since childhood. Imaging examinations demonstrated hemi-hydranencephaly with a nearly complete absence of the right cerebral hemisphere, which was replaced with a membranous sac filled with CSF. She was accompanied with a frontal midline tumor containing lipids. After ventriculoperitoneal shunt, the CSF rhinorrhea completely ceased and no direct repair of the CSF fistula was necessary. The ventriculoperitoneal shunt procedure changes the CSF flow dynamics and releases the intracranial pressure, which may be a simple and effective procedure for CSF rhinorrhea in hemi-hydranencephaly.

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.
METHODS: 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).
CONCLUSIONS: 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.
METHODS: 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 .

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.
METHODS: 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.
CONCLUSIONS: This case demonstrates the value of endoscopic endonasal transpterygoid corridor in the exposure and manipulation of the sphenoid lateral recess.

本文报道了1例复发性鼻窦内翻性乳头状瘤鼻内镜术后迟发性脑脊液鼻漏病例。患者男，50岁，因“鼻内镜术后5 d，头痛伴高热3 d”转诊，有糖尿病史（血糖控制欠佳）、2次鼻内镜手术史。第2次外院鼻内镜手术后，患者出现高热、头痛、鼻腔清水样分泌物，鼻内镜检查发现脑脊液鼻漏，漏口位于曾使用单极电凝止血的筛顶。保守治疗无效后，控制血糖后予以鼻内镜下脑脊液鼻漏修补术，术后随访肿瘤无复发，无再次脑脊液鼻漏。.

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.
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.
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.
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.