The field of endoscopic endonasal surgery is in a constant state of advancement, with an expanding range of applications. Improvement in the diversity of instruments available, along with the increasing proficiency of surgical teams, has enabled the successful endoscopic treatment of complex sinonasal and skull base malignancies. Not only is the overall complication rate reduced by endoscopic approaches, but survival outcomes have also shown promising results when compared to traditional open approaches.

BACKGROUND: Cerebral cavernous hemangiomas (CHs) are the most common vascular malformations and can be found in many locations in the brain. The most common extra-axial locations are the intrasellar and parasellar regions. Both locations are rare for CH.
METHODS: A 41-year-old female who had experienced headaches for about a year presented to the authors\' institution because of a mass located in the left cavernous sinus (CS). It was confirmed that it was not causing any loss in the visual field and that there was no pituitary irregularity. Surgery was planned with a preliminary diagnosis of CH. An endoscopic endonasal approach (EEA) was undertaken with the otorhinolaryngology team. The dura mater was opened following excision of the back wall of the sphenoid sinus. A blue-purple vascular lesion was observed, filling the left CS. Gross-total resection (GTR) was achieved. In the literature, there were 10 cases in which GTR had been performed using the EEA.
CONCLUSIONS: Patients with CHs located in the sellar region present with various complaints. The preference for endoscopic surgery over cranial surgery for such lesions requires more comprehensive studies, but it is thought that this approach can reduce surgical complications and the time to discharge for the patient. https://thejns.org/doi/abs/10.3171/CASE24227.

BACKGROUND: The upper respiratory mucosa plays a crucial role in both the physical integrity and immunological function of the respiratory tract. However, in certain situations such as infections, trauma, or surgery, it might sustain damage. Tissue engineering, a field of regenerative medicine, has found applications in various medical fields including but not limited to plastic surgery, ophthalmology, and urology. However, its application to the respiratory system remains somewhat difficult due to the complex morphology and histology of the upper respiratory tract. To date, a culture protocol for producing a handleable, well-differentiated nasal mucosa has yet to be developed. The objective of this review is to describe the current state of research pertaining to cell culture techniques used for producing autologous healthy human upper respiratory cells and mucosal tissues, as well as describe its clinical applications.
METHODS: A search of the relevant literature was carried out with no time restriction across Embase, Cochrane, PubMed, and Medline Ovid databases. Keywords related to \"respiratory mucosa\" and \"culture techniques of the human airway\" were the focus of the search strategy for this review. The risk of bias in retained studies was assessed using the Joanna Briggs Institute\'s (JBI) critical appraisal tools for qualitative research. A narrative synthesis of our results was then conducted.
RESULTS: A total of 33 studies were included in this review, and thirteen of these focused solely on developing a cell culture protocol without further use. The rest of the studies used their own developed protocol for various applications such as cystic fibrosis, pharmacological, and viral research. One study was able to develop a promising model for nasal mucosa that could be employed as a replacement in nasotracheal reconstructive surgery.
CONCLUSIONS: This systematic review extensively explored the current state of research regarding cell culture techniques for producing tissue-engineered nasal mucosa. Bioengineering the nasal mucosa holds great potential for clinical use. However, further research on mechanical properties is essential, as the comparison of engineered tissues is currently focused on morphology rather than comprehensive mechanical assessments.

CONCLUSIONS: Interpretation of surgical mapping is essential for postoperative radiotherapy planning. Operative and pathological reports lack comprehensive information on margins quality and tissue block mapping. Standardizing reports is essential to reduce uncertainties, aiming for less morbid poRT.

BACKGROUND: 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.
METHODS: 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.
CONCLUSIONS: 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.

As the indications for endoscopic skull base approaches have increased, so has the need for more versatile vascularized flaps for skull base reconstruction. Here, we describe a novel lateral based nasopharyngeal flap (LNPF). Two cadaver heads were dissected to elucidate flap anatomy, dimensions, and technique. A retrospective review was performed on two cases where LNPF was used to repair CSF leaks in the nasopharyngeal area, and outcomes reported. The LNPF is an ascending pharyngeal artery myomucosal flap that includes the nasopharyngeal mucosa and the superior pharyngeal constrictor muscle. The flap was 1.2 × 2.2 cm in greatest dimensions. The LNPF was used for salvage CSF leak repair in two cases: one clival and one tubal. Both patients had resolution of leak at 7 months follow-up. The LNPF is a novel flap with reconstruction potential for the nasopharynx, including the lower clivus and the eustachian tube.

BACKGROUND: Endoscopic endonasal surgical resection is an effective therapeutic approach for olfactory neuroblastoma (ONB). Unilateral excision of ONBs with limited extension has been reported with the purpose of preserving olfactory function. We aimed to review implications of surgical management, olfactory preservation feasibility, and survival outcomes in patients who underwent endoscopic unilateral resection of ONB.
METHODS: A systematic literature review was conducted using the search terms [(\"Olfactory neuroblastoma\") OR (\"Esthesioneuroblastoma\")] AND [(\"Unilateral resection\") OR (\"Olfaction preservation\")]. Studies reporting cases of unilateral ONB endoscopic resection with postoperative olfaction assessment were included. Concurrently, records of patients who met inclusion criteria at our institution were reviewed retrospectively. The survival and olfactory outcomes were analyzed in both cohorts.
RESULTS: Thirty-three patients were identified in the published literature. Twenty-three (69.7%) reported postoperative olfaction preservation. Olfactory function after surgery did not show an association with Kadish stage (P = 0.128). No evidence of disease was observed at the latest follow-up in this group of patients. Nine patients who met inclusion criteria were identified at our institution. The extent of resection influenced the level of olfaction preservation when cribriform plate and nasal septum resection coexisted (P = 0.05). A single patient at our institution developed recurrence after being lost to follow-up for 22 months.
CONCLUSIONS: Olfaction preservation can be achieved in patients who undergo endoscopic unilateral resection and adjuvant radiotherapy. The extent of resection should aim for negative margins, particularly in the midline. Larger studies are required to assess the risk of contralateral microscopic disease, and, hence, close follow-up is advised.

Objective  The endoscopic endonasal approach has emerged as an excellent option for the treatment of lesions involving the petroclival fissure (PCF). Here, we investigate the surgical anatomy of the ventral PCF and its application in endoscopic endonasal surgery. Methods  Sixteen head specimens were used to investigate the anatomical features of PCF and relevant technical nuances in translacerum, extreme medial, and contralateral transmaxillary (CTM) approaches. Two representative endoscopic endonasal surgeries involving the PCF were selected to illustrate the clinical application. Results  From the endoscopic endonasal view, the ventral PCF is presented as a lazy L sign, which is divided into two distinct segments: (1) upper (or petrosphenoidal) segment, which extends vertically from the foramen lacerum inferiorly to the junction of the petrosal process of sphenoid bone and petrous apex superiorly, and (2) lower (or petroclival) segment, which extends inferolaterally from the foramen lacerum to the ventral jugular foramen. Approaching both segments of the ventral PCF first requires full exposure of the foramen lacerum, followed either by exposure of the anterior wall of cavernous sinus and paraclival internal carotid artery for upper segment access, or transection of pterygosphenoidal fissure and Eustachian tube mobilization for lower segment access. Combined with a CTM approach, the lateral extension of the surgical access can be improved for both upper and lower segment PCF approaches. Conclusion  This study provides a detailed investigation of the microsurgical anatomy of the ventral part of PCF, relevant surgical approaches, and technical nuances that may facilitate its safe exposure intraoperatively.

OBJECTIVE: Various nonvascularized or vascularized techniques have been adopted in endoscopic endonasal surgery (EES) for repairing intraoperative cerebrospinal fluid (CSF) leaks after tumor resection. Vascularized nasoseptal flaps, free nasoseptal grafts, free turbinate grafts, and fascia lata and mashed muscle are frequently used. Outcomes of those grafts applied in the defects of different regions need to be clarified.
METHODS: The data from a series of 162 patients with skull base tumor who underwent EES that had intraoperative CSF leak between Jan 2012 and Jan 2021 were retrospectively analyzed. The regions included anterior skull base, sellar region, clivus and infratemporal fossa. Repair failure rate (RFR), meningitis rate, and associated risk factors were assessed.
RESULTS: In total, 172 reconstructions were performed in 162 patients for the 4 sites of the skull base. There were 7 cases (4.3%) that had postoperative CSF leaks, which required second repair. The RFR for anterior skull base, sellar region, clivus, and infratemporal fossawas 2.6%, 2.2%, 16.7%, and 0%, respectively. The clivus defect was an independent risk factor for repair failure (P < 0.01). The postoperative meningitis rate was 5.6%. Repair failure was an independent risk factor for meningitis (P < 0.01).
CONCLUSIONS: Vascularized nasoseptal flap, free nasoseptal graft, free turbinate graft, and fascia lata and mashed muscle are reliable autologous materials for repairing the dural defects in different regions during EES. Clivus reconstruction remains a great challenge, which had a higher RFR and meningitis rate. Repair failure is significantly associated with postoperative meningitis.

OBJECTIVE: The study intends to clarify the optimal endoscopic endonasal surgical strategy for symptomatic Rathke\'s cleft cysts (RCCs).
METHODS: We retrospectively analyzed patients with RCCs that underwent EEA surgery. The strategy for surgical and reconstruction method selection was presented. Patients were split into groups of fenestration open or closed. Pre- and postoperative symptoms, imaging, ophthalmologic, and endocrinologic exams were reviewed. The incidence of complications and the recurrence rates were determined.
RESULTS: The 75 individuals were all received primary operations. The fenestration closed group contained 32 cases, while the fenestration open group contained 43 cases. The median follow-up period was 39 months. The three primary complaints were headache (n = 51, 68.00%), vision impairment (n = 45, 60.00%), and pituitary dysfunction (n = 16, 21.33%). Of the 51 patients with preoperative headaches, 48 (94.12%) reported improvement in their symptoms following surgery. Twenty-three out of 45 patients (51.11%) experienced an improvement in visual impairment. Pituitary dysfunction was found improved in 14 out of 16 individuals (87.50%). There was no discernible difference in the rate of symptom alleviation between both groups. There were three patients (3/75, 4.00%) had cyst reaccumulation. One of them (1/75, 1.33%), which needed reoperation, was healed using pterional approach. In term of complications, cerebral infections occurred in two patients (2/75, 2.67%). Both of them recovered after antibiotic treatment. No postoperative cerebrospinal fluid rhinorrhea occurred. One patient (1/75, 1.33%) in the open group experienced epistaxis. There was no persistent hypopituitarism or diabetes insipidus (DI). Analysis of headache related factors showed that the presence of wax like nodules was related to it.
CONCLUSIONS: RCC was successfully treated with endoscopic endonasal surgery with few problems when the fenestration was kept as open as feasible. Preoperative identification of T2WI hypointense nodules may be a potential reference factor for surgical indication.