Endoscopic Endonasal Skull Base Surgery Research Articles

Diabetes Insipidus After Endoscopic Endonasal Pituitary Macroadenoma Resection, Correlation of Patient and Surgery-Related Risk Factors

Purpose: To identify patient and surgery related factors that could predict the development of postoperative central diabetes insipidus (CDI). Methods: This is a retrospective case-control study conducted at a single-institution tertiary referral center. Patients undergoing endoscopic endonasal skull base surgery for pituitary adenoma between November 2018 and April 2023 were recruited. The main outcome measures collected include age, gender, comorbidities, tumor type, postoperative diabetes insipidus, intraoperative and postoperative cerebrospinal fluid (CSF) leak, flow of CSF leak, number of layers required for repair, the use of nasal packing, and hospital length of stay. Results: A total of 20 patients developed DI postoperatively. Patients demographic and comorbidity profile did not correlate with DI development. The encounter of an intraoperative CSF leak was correlated with post-op DI (X2(1) =18.35, p<0.001) with a RR of 2.7 (CI=1.37-5.28). The use of nasal packs was also correlated with post-op DI (X2(1) =10.17, p=0.001) with a RR of 1.8 (CI=1.15-2.87). Defects requiring a two or more layers for reconstruction also correlated with post-op DI compared to single layer repairs (X2(1) =12.15, p<0.001) irrelevant of the materials used. Development of DI post-op correlated with an increased hospital length of stay (t(64) = -3.35, p =0.001). Conclusion: The physician should be careful when evaluating patients with pituitary adenomas in the postoperative period, particularly those with intraoperative CSF leak, nasal packing, and those who underwent multilayer reconstruction of the surgical defect.

Interdisciplinary Management of Skull Base Tumors.

Endoscopic endonasal skull base surgery has gained acceptance worldwide. Comparative analysis has demonstrated that endoscopic skull base surgery may have advantages for many pathologies of the anterior skull base, e. g., sinonasal malignant tumors; pathologies of the central skull base, e. g., pituitary adenomas, craniopharyngiomas; well-selected cases of planum sphenoidale and tuberculum sellae meningiomas; or for clival lesions, e. g., chordomas, chondrosarcomas, or selected meningiomas. Over the past three decades, interdisciplinary surgical teams, consisting of otolaryngologists and neurosurgeons, have provided detailed anatomical knowledge, suggested new approaches or modifications of established surgical techniques, and offered continued surgical education. A review of pertinent literature was conducted with an emphasis on interdisciplinary endoscopic surgery of skull base lesions. Based on the authors̓ surgical experience in two different interdisciplinary endoscopic skull base centers, the authors classify approaches for endoscopic endonasal skull base surgery, describe indications, and key anatomic landmarks for common pathologies, and highlight surgical techniques to avoid complications. Interdisciplinary endonasal endoscopic surgery combines surgical expertise, improves resection rates for many pathologies, and minimizes morbidity by reducing the incidence of surgical complications.

The importance of the palatine bone for endoscopic endonasal skull base surgery.

Endoscopic endonasal skull base surgery is increasingly prevalent, with its scope expanding from pathogens in the midline region to those in the paramedian region. Maximizing anterior sphenoidectomy is important for the median approach, and lateralizing the pterygopalatine fossa is crucial for the paramedian approach. Maximizing the surgical corridor in the nasal cavity and minimizing damage to neurovascular structures are vital for establishing a surgical field with minimal bleeding, ensuring safe, precise, and gentle procedures. However, the relationship between the maxillofacial and skull base bones in endoscopic endonasal skull base surgery is difficult to understand because these bones are intricately articulated, making it challenging to visualize each bone's outline. Understanding important bones and their related neurovascular structures is essential for all skull base surgeons to maximize the surgical corridor and minimize iatrogenic injury to neurovascular structures. This study aimed to elucidate the role of the palatine bone from a microsurgical anatomical perspective. Three dry skulls were used to demonstrate the structure of the palatine bone and its relationship with surrounding bones. A formalin-perfused cadaveric head was dissected to show the related neurovascular structures. The arteries and veins of the cadaveric heads were injected with red- and blue-colored silicon. Dissection was performed using a surgical microscope and endoscope. In addition, the utilization of the palatine bone as a landmark to identify neurovascular structures, which aids in creating a wider surgical field with less bleeding, was shown in two representative cases. The palatine bone consists of unique complex structures, including the sphenoidal process, ethmoidal crest, pterygopalatine canal, and sphenopalatine notch, which are closely related to the sphenopalatine artery, maxillary nerve, and its branches. The ethmoidal crest of the palatine bone is a well-known structure that is useful for identifying the sphenopalatine foramen, controlling the sphenopalatine artery and nerve, and safely opening the pterygopalatine fossa. The sphenoidal process of the palatine bone is a valuable landmark for identifying the palatovaginal artery, which is a landmark used to safely and efficiently expose the vidian canal. The sphenoidal process is easily cracked with an osteotome and removed to expose the palatovaginal artery, which runs along the pharyngeal groove, just medial to the vidian canal. By opening the pterygopalatine canal (also known as the greater palatine canal), further lateralization of the periosteum-covered pterygopalatine fossa contents can be achieved. Overall, the sphenoidal process and ethmoidal crest can be used as important landmarks to maximize the surgical corridor and minimize unnecessary injury to neurovascular structures.

Paediatric endoscopic endonasal middle skull base reconstruction: retrospective analysis of 78 patients treated in a single tertiary care paediatric center

Introduction Skull base pathologies in the paediatric population are rare and require treatment by multiple qualified specialists. The endoscopic endonasal approach has revolutionized surgical treatment because it is less invasive than existing treatments.The goal of this study was to retrospectively review our experience with the reconstruction of paediatric skull middle base defects and associated complications. Materials and methods We analysed medical records from patients aged ≤ 18 years who were treated at our centre between 2013 and 2021. Patients treated with an endoscopic skull base approach and reconstruction, and who had complete clinical and radiological documentation and a minimum follow-up of 12 months, were included in the analysis. Personal data, reconstructive techniques, and complications were analysed. Results A total of 78 patients met the inclusion criteria and were enrolled in the study. Of these patients, 32 were male and 46 were female, and the mean age was 11.5 years. The main signs and symptoms were as follows: bitemporal hemianopsia in 53 cases, visual impairment in 23 cases, and headache in 30 cases. The most frequent aetiologies were craniopharyngioma (38 cases), pituitary adenoma (23 cases), and clivus chordoma (4 cases). All patients were treated via a pure endoscopic approach. For reconstruction, a multilayer technique was used in 18 cases, naso-septal flap in 43 cases, Gasket-Seal technique in 12 cases, and heterologous reconstruction in 5 cases. Only six patients presented a major complication: two had a postoperative cerebral spinal fluid leak, one developed a brain abscess, and three had diabetes insipidus.The mean follow-up period was 23.4 months.There were no statistically significant differences in postoperative CSF leak in relation to different reconstructive techniques. Conclusion Endoscopic endonasal skull base surgery is a safe and effective treatment for paediatric middle skull base pathologies. Reconstruction techniques have a high success rate of 96.5–100%, and the rate of associated complications is < 3%.

A computed tomography (CT)-based morphometric study of various skull base parameters and their anatomical relationships relevant to endoscopic endonasal skull base surgery.

Endoscopic skull base surgery requires a thorough understanding of skull base anatomy. Orientation to regional anatomy to avoid complications like internal carotid artery injury can be assisted by knowledge of certain bony landmarks. These landmarks are themselves highly variable structures. This study focuses on the radiological morphometric characterization of these landmarks, which can be of great assistance to surgeons for better planning of endoscopic skull base approaches. Computed tomography scans of patients without skull base pathologies were analyzed retrospectively for the following parameters - Vidian canal (VC) length, VC and foramen rotundum (FR) distance from midline, the angle between the axis of VC and petrous internal carotid artery (pICA) and between VC and palatovaginal canal, the horizontal, vertical and direct distances between VC and FR and the patterns of sphenoid sinus (SS) pneumatization. The VC-pICA angle was more obtuse and VC and FR were placed farther off the midline on the left as compared to the right side. Similarly, the distances between VC and FR were more on the left side. The VC length and distance of VC and FR from the midline were longer in males than in females. The VC-pICA angle was more obtuse in females. The post-sellar variant was the predominant pneumatization pattern seen (57.9%), and the incidence of lateral recess pneumatization was 15%. The results of our study can be utilized for a better understanding of the anatomy of the skull base. In skull base pathologies with distorted anatomical landmarks, a basic understanding of their interrelations can be used to have a better anatomical orientation. All these measures can help in avoiding complications and make extended endoscopic approaches safe.

Validation of Korean Olfactory Questionnaire for Perioperative Olfactory Assessment in Endoscopic Endonasal Skull Base Surgery.

Objective: To analyze changes in olfactory function after endoscopic endonasal skull base surgery and compare performance of the olfactory questionnaire with those of conventional psychophysical tests. Methods: Patients were classified into 5 categories for olfactory function evaluation (normal, mild hyposmia, moderate hyposmia, severe hyposmia, and anosmia) based on a self-assessment. Patients also underwent the butanol threshold test (BTT), Cross-Cultural Smell Identification Test (CCSIT), and 11-item olfactory questionnaire. Subjects with normosmia preoperatively and who were followed up at least 6 months after surgery were analyzed. Receiver operating characteristic curves and confusion matrix analysis were performed for BTT, CCSIT, and olfactory questionnaire to compare their diagnostic abilities. The effects of age, preoperative olfaction, septal flap, tumor pathology, and tumor size on postoperative olfaction were evaluated using multivariate linear regression analysis. Results: Data from 108 patients were analyzed. Postoperative changes in the olfactory questionnaire were significantly associated with changes in the BTT and CCSIT. The area under the curve for postoperative self-olfactory function classification was highest for olfactory questionnaire (0.894), followed by BTT (0.767) and CCSIT (0.688). Patient age at the time of surgery and preoperative BTT score were significantly related to postoperative olfactory outcomes. Conclusion: The olfactory questionnaire correlated well with conventional psychosomatic olfactory function tests. In combination with clinical parameters and preoperative psychosomatic olfactory function tests, the olfactory questionnaire is suitable for assessing subjective olfactory function after endoscopic endonasal skull base surgery.

Impact of collagen matrix on reconstructive material selection and postoperative complications in endoscopic endonasal skull base surgery.

The aim of this study was to investigate the impact of collagen matrix on reconstructive material selection and postoperative complications in endoscopic endonasal skull base surgery. The authors retrospectively reviewed the data of consecutive patients who underwent purely endoscopic endonasal skull base surgery from January 2015 to March 2023. Intraoperative CSF leakage was classified according to the Esposito grade, and skull base repair was tailored to the leakage grade. The patients were divided into two groups: before (group A) and after (group B) collagen matrix implementation. The rates of autologous graft harvesting (fat, fascia, and nasoseptal flap), postoperative CSF leakage, and donor-site complications were compared between the two groups. In total, 270 patients were included. Group A included 159 patients and group B included 111 patients. There were no differences in patient characteristics, including age, pathology, and Esposito grade, between the two groups. The overall fat usage rate was significantly higher in group A (63.5%) than in group B (39.6%) (p = 0.0001), and the fascia usage rate was also significantly higher in group A (25.8%) than in group B (4.5%) (p < 0.0001). The nasoseptal flap usage rate did not differ between group A (32.7%) and group B (30.6%) (p = 0.79). Postoperative CSF leakage was similar between the two groups (0.63% in group A vs 1.8% in group B, p = 0.57), and the overall rate of CSF leakage was 1.1%. Donor-site complications occurred in 3 patients in group A, including 1 abdominal hematoma, 1 delayed abdominal infection, and 1 fluid collection after fascia lata harvesting. Collagen matrix implementation significantly decreased autologous graft harvesting without increasing postoperative CSF leakage, contributing to less invasive surgery.

Sinonasal Quality of Life After Endoscopic Endonasal Skull Base Surgery

This article is written to provide the reader with an overview of the sinonasal quality-of-life considerations for patients undergoing endoscopic endonasal skull base surgery.

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

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

Gender Differences in Quality-of-Life Outcome in Patients Undergoing Endoscopic Endonasal Skull Base Surgery

Abstract Background Prior studies showed that female patients with chronic rhinosinusitis (CRS) suffer a worse disease-specific quality of life (QoL). Goal The aim of this study is to investigate gender differences in sinonasal QoL outcomes in patients requiring endoscopic endonasal skull base surgeries (EESBS). Methods Cross-sectional analysis of patients presenting to our clinic from August 2020 to December 2022 with skull base tumors, spontaneous cerebrospinal fluid (CSF) rhinorrhea, or Grave's orbitopathy (for orbital decompression) was performed. Baseline and postsurgical QoL were measured using the 22-item Sinonasal Outcome Test (SNOT-22). Patients' demographics and comorbidities were reviewed. Patients with concomitant CRS were excluded. Results Eighty-six patients were included (54 with skull base tumors, 17 Grave's orbitopathy, and 15 spontaneous CSF rhinorrhea). The mean age of the patients was 52 years (range: 12.4–81.5 years), and 51.6% of the patients were females. There was no age difference between female and male patients. Smoking history, asthma, and allergic rhinitis were also similar between the two groups. Female patients had a significantly higher incidence of depression (58.3 vs. 32.4%, p = 0.018) and migraine (50.0 vs. 21.6%, p = 0.007). Female patients had a significantly worse overall SNOT-22 scores at baseline (33.6 vs. 18.2, p = 0.001), at the 3-month follow-up (29.7 vs. 15.5, p = 0.002), and at the 6-month follow-up (33.5 vs. 14.9, p = 0.005). This worse QoL was seen mainly in the ear/facial, sleep, and psychological domains. Linear regression of the SNOT-22 scores and its subdomains adjusting for comorbidities showed that migraine was found to be the most significant determinant of gender differences in the QoL. Conclusion Female patients who undergo EESBS show higher overall SNOT-22 scores secondary to higher incidence of migraine.

Electromyographic predictors of abducens nerve palsy after endoscopic skull base surgery.

Recovery of abducens nerve palsy (ANP) after endoscopic endonasal skull base surgery (ESBS) has been shown to be potentially predicted by postoperative ophthalmological examination. Triggered electromyography (t-EMG) and free-run electromyography (f-EMG) activity provide an intraoperative assessment of abducens nerve function, but associations with long-term ANP outcomes have not been explored. The objective of this study was to describe intraoperative abducens EMG characteristics and determine whether these electrophysiological profiles are associated with immediately postoperative and long-term ANP outcomes after ESBS. The authors conducted a 5-year (2011-2016) retrospective case-control study of patients who underwent ESBS in whom the abducens nerve was stimulated (t-EMG). Electrophysiological metrics were compared between patients with a new postoperative ANP (cases) and those without ANP (controls). Pathologies included chordoma, pituitary adenoma, meningioma, cholesterol granuloma, and chondrosarcoma. Electrophysiological data included the presence of abnormal f-EMG activity, t-EMG stimulation voltage, stimulation threshold, evoked compound muscle action potential (CMAP) amplitude, onset latency, peak latency, and CMAP duration at various stages of the dissection. Controls were selected such that pathologies were similarly distributed between cases and controls. Fifty-six patients were included, 26 with new postoperative ANP and 30 controls without ANP. Abnormal f-EMG activity (28.0% vs 3.3%, p = 0.02) and lack of response to stimulation (27% vs 0%, p = 0.006) were more frequent in patients with immediately postoperative ANP than in controls. Patients with immediately postoperative ANP also had a lower median CMAP amplitude (35.0 vs 71.2 μV, p = 0.02) and longer onset latency (5.2 vs 2.8 msec, p = 0.04). Comparing patients with transient versus persistent ANP on follow-up, those with persistent ANP tended to have a lower CMAP amplitude (12.8 vs 57 μV, p = 0.07) and higher likelihood of not responding to stimulation at the end of the case (45.5% vs 7.1%, p = 0.06). Abnormal f-EMG was not associated with long-term ANP outcomes. The presence of f-EMG activity, lack of CMAP response to stimulation, decreased CMAP amplitude, and increased CMAP onset latency were associated with immediately postoperative ANP. Long-term ANP outcomes may be associated with t-EMG parameters, including whether the nerve is able to be stimulated once identified and CMAP amplitude. Future prospective studies may be designed to standardize abducens nerve electrophysiological monitoring protocols to further refine operative and prognostic utility.

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

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

Use of patient-specific 3D printed models in pre-operative counseling for pediatric skull base surgery.

Pediatric cranial base pathology is anatomically complex and surgical treatment is oftentimes difficult to conceptualize for patients and their families. Three-dimensional (3D) models of the sinuses and cranial base have the potential to enhance patient understanding in numerous domains. Our objective is to assess the use of 3D models in pre-operative parental and patient counseling prior to endoscopic endonasal skull base surgery in the pediatric population. A survey was designed to assess parent and patient-perceived utility of 3D-printed models in surgical counseling prior to pediatric skull base surgery. A total of 10 patients were included. The median age was 9 years (range=5 months-15 years). Pathology included juvenile nasopharyngeal angiofibroma (JNA) (N=4), fibrous dysplasia of the maxilla and sphenoid (N=1), juvenile ossifying fibroma (N=1), nasal dermoid (N=2, one with intracranial extension), encephalocele (N=1), and parapharyngeal ectopic glial tissue (N=1). Nearly all parents agreed or strongly agreed that 3D printed models were helpful in explaining the patient's skull base pathology (N=10), surgical plan (N=10), and possible complications (N=9). All parents strongly agreed that 3D models should be used routinely in pre-operative counseling for endoscopic endonasal surgery. According to a majority of parents, patients older than 4 years old found the models helpful in understanding their pathology (75%) and surgery (88%). By allowing direct three-dimensional visualization of the target pathology, 3D models serve as a useful adjunct in enhancing patient comprehension of the pathologic entity, planned surgery, and potential complications prior to pediatric endoscopic endonasal skull base surgery.

DOTATATE PET Imaging in Olfactory Neuroblastoma and Association with SSTR Expression

Abstract Introduction Olfactory neuroblastoma (ONB), or esthesioneuroblastoma, is a rare neuroectodermal tumor of the nasal cavity and paranasal sinuses. Most of these tumors express somatostatin receptors (SSTRs), providing a potential target for radionuclide imaging with Ga-68 DOTATATE. However, this imaging modality has not been extensively studied in ONB. Methods We conducted a retrospective chart review of 96 endoscopic endonasal skull base surgery cases for ONB performed at our institution between 2000 and 2021. Histo (H) scores were assigned to each tumor and normalized DOTATATE standardized uptake values (nSUVs) were measured as well. Results Nine patients (5 males and 4 females) with ONB were ultimately included in the study. The average age of the patients was 50 years. All ONBs had a positive SSTR2 expression (H-score &gt; 105; mean: 180). All ONBs showed DOTATATE avidity (mean nSUV for ONB: 6.7). However, there was no correlation between H-score and nSUV, with an r 2 of 0.24 (p = 0.18). Conclusion Our study shows that SSTR2 expression is found in all ONBs with associated DOTATATE avidity, which may serve as a valuable imaging modality to monitor for recurrent and metastatic disease in ONB.

Operating Room Assessment in Endoscopic Skull Base Surgery

Since the introduction of endoscopic endonasal surgery for skull base pathologies in the 1990s [1], increasing experience with this technique has led to many progressive changes in patient positioning, technique, and assessment in the operating room. In addition, new surgical instruments have been developed for endoscopic endonasal skull base surgery. We present our experience and assessment of the operating room.

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

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

Otolaryngology Considerations of Pituitary Surgery: What an Endocrinologist Should Know.

Endoscopic endonasal skull base surgery is the preferred surgical approach for the management of pituitary adenomas. Perioperative management of pituitary lesions requires multidisciplinary care and typically includes a dual surgeon team consisting of a neurosurgeon and an otolaryngologist. The involvement of the otolaryngologist allows for a safe surgical approach with excellent intraoperative visualization of the tumor to enable an effective resection of the tumor by the neurosurgeon. Detection and treatment of sinonasal pathology is essential prior to surgery. Patients may experience sinonasal complaints following endoscopic transsphenoidal surgery, although this is typically temporary. Sinonasal care in the postoperative period can expedite recovery to baseline. Here we discuss the perioperative factors of endoscopic pituitary surgery that endocrinologists should be aware of, ranging from preoperative patient selection and optimization to postoperative care, with a particular emphasis on anatomic and surgical factors.

The Predictors of Postoperative Cerebrospinal Fluid Leak in Endoscopic Endonasal Pituitary Surgery: The Role of Tumor Volume.

Objectives Postoperative cerebrospinal fluid (Po-CSF) leak is still a challenging complication of endoscopic endonasal skull base surgery. However, data describing the predictive factors of Po-CSF leak in pure pituitary adenomas is lacking. Aim of this study is to determine the risk factors of Po-CSF leak in a pituitary adenoma group operated via pure transsellar endoscopic approach. Design This is a retrospective cohort study. Setting A single-center academic hospital. Participants Patients operated for a pituitary adenoma between 2015 and 2021 and followed up until June 2022 were included. Main Outcome Measures Demographics, comorbidities, imaging, and outcome were recorded. Univariate and multivariate logistic regression analyses were used to determine the risk factors of Po-CSF leak. Results Of the total 170 patients with a mean age of 47.5 ± 13.8 (min: 15; max: 80), 11 (6.5%) had Po-CSF leak. Univariate analysis revealed age, diabetes mellitus (DM), and tumor volume as predictors of Po-CSF leak. According to the receiver operating characteristic analysis, 7.5 cm 3 of tumor volume was found to be a good cutoff value with a sensitivity of 82% and a specificity of 75%. Hence, multivariable logistic regression model adjusted by age showed that a tumor volume of > 7.5 cm 3 (odds ratio [OR]: 22.9; 95% confidence interval [CI]: 3.8-135.9, p = 0.001) and DM (OR: 8.9; 95% CI: 1.7-46.5; p = 0.010) are strong independent risk factors of Po-CSF leak in pure endoscopic endonasal pituitary surgery. Conclusion Besides younger age and DM, a cutoff value for tumor volume > 7.5 cm 3 is the most remarkable risk factor for Po-CSF leak in pure endoscopic pituitary surgery. These patients should carefully be assessed preoperatively and potential preemptive surgical strategies should be taken into consideration to avoid complications.

The Pterygosphenoidal Triangle: Surgical Anatomy and Case Series in Endoscopic Endonasal Skull Base Surgery.

Safe exposure of the lacerum segment of the carotid artery remains a challenge in endoscopic endonasal surgery. To introduce the pterygosphenoidal triangle as a novel and reliable landmark for facilitating access to the foramen lacerum. Fifteen colored silicone-injected anatomic specimens were dissected using an endoscopic endonasal approach to the foramen lacerum region in a stepwise manner. Twelve dried skulls were studied and 30 high-resolution computed tomography scans were analyzed to measure the borders and angles of the pterygosphenoidal triangle. Surgical cases incorporating the foramen lacerum exposure between July 2018 and December 2021 were reviewed to provide surgical outcomes of the proposed surgical technique. The pterygosphenoidal triangle is delineated by the pterygosphenoidal fissure medially and the vidian nerve laterally. The palatovaginal artery is located at the base of the triangle anteriorly, while the apex is formed by the pterygoid tubercle posteriorly, which leads to the anterior wall of the foramen lacerum and lacerum internal carotid artery. In the reviewed surgical cases, 39 patients underwent 46 foramen lacerum approaches for resection of pituitary adenoma (12 patients), meningioma (6 patients), chondrosarcoma (5 patients), chordoma (5 patients), or other lesions (11 patients). There were no carotid injuries or ischemic events. Near-total resection was achieved in 33 (85%) of 39 patients (gross-total in 20 [51%]). This study details the pterygosphenoidal triangle as a novel and practical anatomic surgical landmark for safe and effective exposure of the foramen lacerum in endoscopic endonasal surgery.

879 Monitoring Flash Visual Evoked Potentials During Endoscopic Skull Base Surgery Reduces the Risk of Visual Pathway Injury

INTRODUCTION: Minimally invasive endoscopic endonasal skull base surgery offer safer and more effective access to the skull base to remove benign and malignant tumors. However, endoscopic skull base surgery around the visual pathway may increase the risk of injury of the visual pathway. Monitoring of flash visual evoked potentials (FVEPs) during surgery may detect a possible injury to the visual pathway, allowing the surgeon to take corrective measures during surgery to reverse or minimize it. METHODS: We identified patients with chiasmatic or pre-chiasmatic lesions who underwent minimally invasive endoscopic skull base surgery. Patients were subjected to eye exam (color vision, visual acuity, and visual field evaluation) within 3 months before surgery, and within 6-12 weeks and 6-9 months after surgery to explore short- and long-term surgical outcomes on eyesight. During surgery, FVEPs were recorded from electrodes placed in the scalp overlying the visual cortex after flashing red light stimulation (Cadwell LED stimulating goggles), as reported previously. We examined the relationship between FVEPs amplitude change and visual outcome on these patients. RESULTS: 102 patients have been enrolled in this retrospective study. The median age at admission was 57 years (range: 22-86 years) and 68.4% of the patients were female. Most of the patients had either pituitary adenoma (64.7%) or skull base meningioma (23.5%). Preliminary eye evaluations (pre- and post-surgery) showed that the patients did not develop short- or long-term eyesight impairments. CONCLUSIONS: Our study provides a new method for rapidly acquiring reproducible FVEP waves for which allows for timely reporting significant FVEP changes resulting in prompt signal action. Thus, monitoring FVEPs during endoscopic endonasal skull base surgery reduces the risk of visual pathway injury.