Endoscopic endonasal skull base surgery: analysis of complications in the authors' initial 800 patients

Simultaneous combined keyhole mini-transcranial approach and endoscopic transsphenoidal approach to remove multi-lobulated pituitary neuroendocrine tumor with suprasellar extension

BACKGROUND

Transsphenoidal surgery (TSS) is the main method to remove pituitary neuroendocrine tumor (PitNET), but large or multi-lobulated one is still challenging.

OBJECTIVE

The less invasive simultaneous combined keyhole mini-transcranial approach and standard transsphenoidal approach was used to remove multi-lobulated or hourglass-shaped non-functioning PitNET to avoid the specific complications related to extended TSS.

METHODS

Twenty-one patients of large multi-lobulated or hourglass-shaped PitNET (6 patients were recurrent cases after TSS or transcranial approach) were treated by this simultaneous combined approach. The supraorbital or midline keyhole approach was performed under the operating microscope so that the fine arteries feeding optic apparatus were dissected from the tumor capsule safely and securely and the suprasellar part of the tumor was removed in the extra-capsular fashion in combination with transsphenoidal approach.

RESULTS

Visual function improved after the surgery in 14 (74 %) of 19 patients with preoperative disturbance of the visual fields. Four patients (19 %) developed postoperative deterioration of pituitary endocrine functions requiring permanent hormonal replacement. One patient (4.2 %) suffered cortical laminar necrosis without permanent disorders and another patient (4.2 %) suffered cerebrospinal fluid rhinorrhea but neither was permanent. Postoperative computed tomography detected no subarachnoid hemorrhage in any patient. Gross total removal was achieved in 15 patients (71 %). Five patients (24 %) with subtotal removal and one patient (4.2 %) with partial removal had lateral tumor extension with Knosp classification 3 or 4.

CONCLUSION

The combined method is an effective treatment option to remove complex PitNET safely and securely with dissecting fine arteries on the tumor capsule.

Endoscopic Transpterygoid Repair of Sphenoid Sinus Meningocele: A Comprehensive Case Report and Literature Review

We report a challenging and uncommon case involving a 53-year-old Japanese man with cerebrospinal fluid (CSF) leakage caused by a meningocele in the lateral recess of the sphenoid sinus. Our innovative treatment approach involved a combination of transpterygoid and endoscopic modified medial maxillectomy techniques, with special emphasis on the preservation of the sphenopalatine artery. This strategic preservation was pivotal to the successful use of the ipsilateral nasoseptal flap for reconstruction, which played a crucial role in the prevention of postoperative CSF leakage. Otolaryngologists and neurosurgeons collaborated to perform the bath-plugging technique; effective collaboration was instrumental to the success of the procedure. This report highlights significant advancement from conventional frontal craniotomy to a more sophisticated endoscopic technique, shows the importance of meticulous surgical planning and execution, emphasizes careful preservation of critical anatomical structures during complex neurosurgical and otolaryngological procedures, and underscores the evolving landscape of surgical approaches for managing complex medical conditions.

Does Time to Initiation of Adjuvant Radiotherapy Affect Reconstruction Outcomes after Endoscopic Resection of Skull Base Malignancies?

Introduction and Objective  It is unclear if the length of the time interval to initiation of adjuvant radiation therapy (RT) after endoscopic endonasal surgery affects reconstruction outcomes. In this study we present our experience with adjuvant RT after endoscopic endonasal procedures, to determine if the time to RT after surgery impacts post-RT reconstruction complication rates. Methods  A retrospective cohort study of 164 patients who underwent endoscopic endonasal surgery between 1998 and 2021 was conducted. Using Cox proportional hazard ratios (HRs), we evaluated several variables and the complications that occurred during the 1-year period after starting RT. Results  Seventy-eight (47.5%) and eighty-six patients (52.5%) received RT before and after the sixth postoperative week, respectively. The overall post-RT complication rates were 28%, most of these were severe infections ( n  = 20, 12.2%) and delayed CSF leak ( n  = 4, 2.5%). There was no significant difference in the post-RT complications between the patients who received postoperative RT before or after the sixth operative week (HR: 1.13; 95% confidence interval: 0.63-2.02; p = 0.675 ). Univariate analysis demonstrated negative impact associated with smoking history ( p = 0.015 ), the use of neoadjuvant chemotherapy ( p = 0.0001 ), and the use of photon therapy ( p = 0.012 ); and we found a positive impact with the use of multilayer reconstruction techniques (overall, p = 0.041 ; with fat, p = 0.038 ; and/or fascia graft, p = 0.035 ). After a multivariate analysis only, smoking history was an independent risk factor for post-RT complications ( p = 0.012 ). Conclusion  Delaying RT for more than 6 weeks after endoscopic endonasal surgery does not provide a significant benefit for reconstruction outcomes. However, special attention may be warranted in patients with smoking history who have received neoadjuvant chemotherapy, or in patients who will receive photon-based RT after surgery as these groups were found to have increased complication rates post-RT.

Contralateral Nasofrontal Trephination: A Novel Corridor for a "Dual Port" Approach to the Petrous Apex

BACKGROUND AND OBJECTIVES

Expanded endonasal approaches (EEAs) have proven safe and effective in treating select petrous apex (PA) pathologies. Angled endoscopes and instruments have expanded indications for such approaches; however, the complex neurovascular anatomy surrounding the petrous region remains a significant challenge. This study evaluates the feasibility, anatomic aspects, and limitations of a contralateral nasofrontal trephination (CNT) route as a complementary corridor improving access to the PA.

METHODS

Expanded endonasal and CNT approaches to the PA were carried out bilaterally in 15 cadaveric heads with endovascular latex injections. The distance to the PA, angle between instruments through the 2 approach portals, and surgical freedom were measured and compared.

RESULTS

Three-dimensional DICOM-based modeling and visualization indicate that the CNT route reduces the distance to the target located within the contralateral PA by an average of 3.33 cm (19%) and affords a significant increase in the angle between instruments (15.60°; 54%). Furthermore, the vertical vector of approach is improved by 28.97° yielding a caudal reach advantage of 2 cm. The area of surgical freedom afforded by 3 different approaches (endonasal, endonasal with an endoscope in CNT portal, and endonasal with an instrument in CNT portal) was compared at 4 points: the dural exit point of the 6th cranial nerve, jugular foramen, foramen lacerum, and petroclival fissure. The mean area of surgical freedom provided by both approaches incorporating the CNT corridor was superior to EEA alone at each of the surgical targets ( P = <.001).

CONCLUSION

The addition of a CNT portal provides an additional avenue to expand on the classical EEA to the PA. This study provides insight into the anatomic nuances and potential clinical benefits of a dual-port approach to the PA.

Long-term outcomes in advanced anterior skull base malignancy: a single quaternary institution experience

BACKGROUND

Advanced skull base malignancies are a heterogenous subset of head and neck cancers, and management is often complex. In recent times, there has been a paradigm shift in surgical technique and the advent of novel systemic options. Our goal was to analyse the long-term outcomes of a single quaternary head and neck and skull base service.

METHODS

A retrospective review of 127 patients with advanced anterior skull base malignancies that were treated at our institution between 1999 and 2015 was performed. Multiple variables were investigated to assess their significance on 5 and 10-year outcomes.

RESULTS

The mean age was 60.9 (± 12.6 SD). Sixty-four percent were males and 36% were females. Ninety percent of patients had T4 disease. Median survival time was 133 months. The 5-year overall survival (OS) was 66.2%, disease-specific survival (DSS) was 74.7%, and recurrence-free survival (RFS) was 65.0%. The 10-year OS was 55.1%, DSS was 72.1%, and RFS was 53.4%. Histological type and margin status significantly affected OS & DSS.

CONCLUSION

Surgical management of advanced skull base tumours has evolved over the last few decades at our institution with acceptable survival outcomes and complication rates. Histological diagnosis and margin status are the main predictors of survival. The addition of neoadjuvant systemic agents in current trials may improve outcomes.

The impact of obesity on rates of post-operative CSF leak following endoscopic skull base surgery: results from a prospective international multi-centre cohort study

Aims

Post-operative CSF leak is the major source of morbidity following transsphenoidal approaches (TSA) and expanded endonasal approaches (EEA) to lesions of the sella turcica and the ventral skull base. There are conflicting reports in the literature as to whether obesity (BMI ≥30) is a risk factor for this complication. We aimed to evaluate data collected as part of prospective multi-centre cohort study to address this question.

Methods

The CRANIAL (CSF Rhinorrhoea After Endonasal Intervention to the Skull Base) study database was reviewed and patients were divided into obese and non-obese cohorts. Data on patient demographics, underlying pathology, intra-operative findings and skull base repair techniques were analysed.

Results

TSA were performed on 726 patients, of whom 210 were obese and 516 were non-obese. The rate of post-operative CSF leak in the obese cohort was 11/210 (5%), compared to 17/516 (3%) in the non-obese cohort, which was not statistically significant (χ2 = 1.520, p=0.217). EEA were performed on 140 patients, of whom 28 were obese and 112 were non-obese. The rate of post-operative CSF leak in the obese cohort was 2/28 (7%), which was identical to the rate observed in the non-obese cohort 8/112 (7%) Fisher's Exact Test, p=1.000). These results persisted following adjustment for inter-institutional variation and baseline risk of post-operative CSF leak.

Conclusion

CSF leak rates following TSA and EEA, in association with modern skull base repair techniques, were found to be low in both obese and non-obese patients. However, due to the low rate of post-operative CSF leak, we were unable to fully exclude a small contributory effect of obesity to the risk of this complication.

The Transorbital Approach: A Comprehensive Review of Targets, Surgical Techniques, and Multiportal Variants

The transorbital approach (TOA) is gaining popularity in skull base surgery scenarios. This approach represents a valuable surgical corridor to access various compartments and safely address several intracranial pathologies, both intradurally and extradurally, including tumors of the olfactory groove in the anterior cranial fossa (ACF), cavernous sinus in the middle cranial fossa (MCF), and the cerebellopontine angle in the posterior cranial fossa (PCF). The TOA exists in many variants, both from the point of view of invasiveness and from that of the entry point to the orbit, corresponding to the four orbital quadrants: the superior eyelid crease (SLC), the precaruncular (PC), the lateral retrocanthal (LRC), and the preseptal lower eyelid (PS). Moreover, multiportal variants, consisting of the combination of the transorbital approach with others, exist and are relevant to reach peculiar surgical territories. The significance of the TOA in neurosurgery, coupled with the dearth of thorough studies assessing its various applications and adaptations, underscores the necessity for this research. This extensive review delineates the multitude of target lesions reachable through the transorbital route, categorizing them based on surgical complexity. Furthermore, it provides an overview of the different transorbital variations, both standalone and in conjunction with other techniques. By offering a comprehensive understanding, this study aims to enhance awareness and knowledge regarding the current utility of the transorbital approach in neurosurgery. Additionally, it aims to steer future investigations toward deeper exploration, refinement, and exploration of additional perspectives concerning this surgical method.

Interdisciplinary Management of Skull Base Tumors

OBJECTIVE

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.

METHOD

A review of pertinent literature was conducted with an emphasis on interdisciplinary endoscopic surgery of skull base lesions.

RESULTS

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.

CONCLUSION

Interdisciplinary endonasal endoscopic surgery combines surgical expertise, improves resection rates for many pathologies, and minimizes morbidity by reducing the incidence of surgical complications.

[Endoscopic endonasal anterior skull base surgery : Presentation of a monocentric entity profile]

BACKGROUND

Extended endoscopic endonasal surgery (EEES) is an essential part of treatment of various pathologies of the anterior skull base. In addition to significant improvements in the quality of life of affected patients and a lower complication profile compared to open skull base surgery, the therapeutic results are comparable if the indications are correct.

MATERIALS AND METHODS

Data of all endoscopic endonasal skull base procedures performed at the University Skull Base Center Hamburg under the direction of the Department of Otorhinolaryngology between June 2018 and November 2022 were retrospectively collected.

RESULTS

A total of 50 cases were identified. Of these, 56% (28/50) were malignant tumors, 24% (12/50) were benign pathologies with direct skull base involvement, and 20% (10/50) were anterior skull base defects with rhinoliquorrhea. In 96% (48/50) of cases, the preoperatively set goal of surgery (representative biopsy, complete resection, closure of the skull base defect) could be achieved. Complications grade III or higher according to Clavien-Dindo occurred in 4/50 cases. During the observation period, n = 5 olfactory neuroblastomas were diagnosed, all of which were exclusively and successfully operated on endoscopically.

CONCLUSION

In recent years, the spectrum of endoscopically resectable pathologies of the anterior skull base has steadily expanded. In particular, midline-related tumors such as olfactory neuroblastoma or iatrogenic/idiopathic skull base defects with cerebrospinal fluid rhinorrhea are treated completely endoscopically with very good results. Nevertheless, there are also limitations to this technique. Due to high variance in the scope of frontobasal surgery, the extent, and the complex anatomy, as well as the overlapping responsibilities of the specialist disciplines, establishment of certified skull base centers and bundling of frontobasal surgery at these centers is highly relevant for quality assurance.

The role of endoscopic endonasal salvage surgery in recurrent or residual craniopharyngioma after a transcranial approach: a systematic review

BACKGROUND

The management of craniopharyngiomas is challenging due to their high rate of recurrence following resection. Excision of recurrent tumors poses further surgical challenges due to loss of arachnoidal planes and adherence to anatomical structures. The endoscopic endonasal approach (EEA) offers a favorable alternative to transcranial approaches for primary craniopharyngiomas. However, the safety and efficacy of EEA for recurrent tumors, specifically after a prior transcranial approach, needs further investigation.

METHODS

We performed a systematic review using PubMed to develop a database of cases of recurrent craniopharyngiomas previously treated with a transcranial approach.

RESULTS

Fifteen articles were included in this review with a total of 75 cases. There were 50 males and 25 females with a mean age of 38 years (range 2-80). One prior transcranial surgery was done in 80.0% of cases, while 8.0% had two and 12.0% had more than two prior surgeries. Radiotherapy after transcranial resection was given in 18 cases (24.0%). Following EEA, vision improved in 60.0% of cases, and vision worsened in 8.6% of the cases. Of cases, 64.4% had pre-existing anterior hypopituitarism, and 43.8% had diabetes insipidus prior to EEA. New anterior hypopituitarism and diabetes insipidus developed in 24.6% and 21.9% of cases, respectively following EEA. Gross total resection (GTR) was achieved in 64.0%, subtotal resection in 32.0%, and partial resection in 4.0% revision EEA cases. GTR rate was higher in cases with no prior radiotherapy compared to cases with prior radiotherapy (72.0% vs 39.0%, p = 0.0372). The recurrence rate was 17.5% overall but was significantly lower at 10.0% following GTR (p = 0.0019). The average follow-up length was 41.2 months (range, 1-182 months).

CONCLUSION

The EEA can be utilized for resection of recurrent or residual craniopharyngiomas previously managed by a transcranial approach.

Predictors and Complications of Cerebrospinal Fluid Leak after Endoscopic Endonasal Surgery: A Single Institution Retrospective Review

Background  The endoscopic endonasal approach (EEA) is a commonly used technique for resection of sellar, suprasellar, and anterior fossa masses. One of the most troublesome complications of this technique is cerebrospinal fluid (CSF) leak. In this study, we evaluate the risk factors and consequences of CSF leak on surgical outcomes. Methods  The current study is a retrospective single-institution cohort study evaluating patients who underwent EEA for sellar and/or suprasellar masses from July 2017 to March of 2020. Risk factors for intraoperative and postoperative CSF leak were evaluated, including sellar defect size, tumor volume and pathology, age, body mass index, prior endoscopic endonasal surgery, lumbar drain placement, nasoseptal and mucosal graft use, year of surgery, and cavernous sinus invasion. Postoperative infection, perioperative antibiotic use, and length of stay were also evaluated. Results  Our study included 175 patients. Sellar defect size ( p  = 0.015) and intraoperative CSF leak ( p  < 0.001) were significantly associated with an increased risk of postoperative CSF leak. Patients with nasoseptal flaps were more likely to have a postoperative CSF leak than those with free mucosal grafts ( p  = 0.025). Intraoperative CSF leak, Cushing's disease, and lumbar drain placement were associated with an increased length of stay. Conclusion  Sellar defect size, intraoperative CSF leak, and nasoseptal flap use were associated with an increased risk of postoperative CSF leak. Intraoperative CSF leak, Cushing's disease, and lumbar drain placement are all associated with an increased length of stay.

The Temporoparietal Fascia Flap Transposition Technique for Ventral Skull Base Reconstruction: Anatomic Analysis and Surgical Application

BACKGROUND AND OBJECTIVES

The temporoparietal fascia (TPF) flap is an alternative for revision endoscopic skull base reconstruction in the absence of the nasoseptal flap, and we aimed to investigate the anatomy and surgical application of TPF flap transposition in endoscopic endonasal surgery.

METHODS

Six lightly embalmed postmortem human heads and 30 computed tomography angiography imaging scans were used to analyze the anatomic features of the TPF flap transposition technique. Three cases selected from a 512 endoscopic endonasal cases database were presented for the clinical application of the TPF flap.

RESULTS

The TPF flap, composed by the deepest 3 scalp layers (galea aponeurotica, loose areolar connective tissue, and pericranium), can be harvested and then transposed through the infratemporal-maxillary-pterygoid tunnel to the ventral skull base. The superficial temporal artery as its feeding artery, gives frontal and parietal branches with similar diameter (1.5 ± 0.3 mm) at its bifurcation. The typical bifurcation was present in 50 sides (83.3%), with single (frontal) branch in 5 sides (8.3%), single (parietal) branch in 2 sides (3.3%), and multiple branches (>2) in 3 sides (5%). The transposed TPF flap was divided into 3 parts according to its anatomic location: (1) infratemporal part with an area of 19.5 ± 2.5 cm2, (2) maxillary part with an area of 23.7 ± 2.8 cm2, and (3) skull base part with an area of 44.2 ± 4 cm2. Compared with the nasoseptal flap, nasal floor flap, inferior turbinate flap, and extended septal flap, the coverage area of the skull base part of the TPF flap was significantly larger than any of them (P < .0001).

CONCLUSION

The TPF flap technique is an effective alternative for endoscopic endonasal skull base reconstruction. The TPF flap could successfully cover large skull base defects through the infratemporal-maxillary-pterygoid tunnel.

Transorbital Route to Intracranial Space

The endoscopic superior eyelid transorbital approach has emerged as a notable and increasingly utilized surgical technique in recent years. This chapter presents an overview of the approach, tracing its historical development and highlighting its growing acceptance within the skull base community.Beginning with an introduction and historical perspective, the chapter outlines the evolution of the transorbital approach, shedding light on its origins and the factors driving its adoption. Subsequently, a comprehensive exploration of the anatomic bone pillars and intracranial spaces accessible via this approach is provided. Hence, five bone pillars of the transorbital approach were identified, namely the lesser sphenoid wing, the anterior clinoid, the sagittal crest, the middle cranial fossa, and the petrous apex. A detailed correlation of those bone targets with respective intracranial areas has been reported.Furthermore, the chapter delves into the practical application of the technique through a case example, offering insights into its clinical utility, indications, and limitations.

CSF leak after pediatric endoscopic endonasal expanded approaches: a series review

PURPOSE

Endoscopic endonasal approaches in the pediatric population pose specific challenges. Management of postoperative cerebrospinal fluid [CSF] leak is probably the major concern. The purpose of the present investigation is to describe and analyze the incidence of postoperative CSF leaks in our pediatric series of endoscopic endonasal approaches.

METHODS

This is a retrospective analysis, case review of our institutional series. Descriptive statistical parameters and bivariate correlations are analyzed.

RESULTS

Twenty-one patients have been operated through endoscopic approaches in our series. Four patients showed a postoperative CSF leak needing a revision surgery; these cases are described in further detail. Approaches expanded beyond the sellar area and non-sellar pneumatization of the sphenoid sinus were significantly associated with a higher risk of postoperative CSF leak.

CONCLUSIONS

CSF leak incidence after endoscopic endonasal approaches is higher in pediatric patients than in adult series. Anatomic and pathologic factors add complexity to these approaches in children. Multilayer closure is advisable to prevent and treat this complication.

Transnasal Endoscopic Pituitary Surgery-The Role of a CT Scan in Individual Tailoring of Posterior Septum Size Resection

OBJECTIVE

This study was designed to evaluate the possibility of predicting the minimum size of septal resection for safe tumor extraction in transnasal paraseptal pituitary adenoma resection from preoperative computed tomography scans.

METHODS

A retrospective CT scan analysis was performed on 20 patients who underwent endoscopic pituitary surgery at the University Hospital in Ostrava. Virtual insertion of the straight instrument into the sphenoid cavity was simulated using a CT scan. The minimum septal resection size was predicted and compared to various diameters in the nasal cavity. The results were then compared with cadaveric dissections, in which septal resections were performed at 1 cm and 2 cm distances from the anterior sphenoid wall. The association between cadaver dissections and CT scan results was studied.

RESULTS

A total of 20 patients who underwent endoscopic transnasal surgery for pituitary adenoma between the years 2020 and 2021 were enrolled in the study. The mean virtual posterior septal size resection needed to reach the medial edge of the ICA with the straight instrument, without infracturing the nasal septum, was 13.2 mm. In cadavers with a 1 cm posterior septal resection, the medial edge of the ICA was reached with the straight instrument. In 2 cm resections, it was possible to reach beyond the lateral edge of the ICA.

CONCLUSION

There is no significant correlation between the minimum septal size resection and measured diameters in the nasal cavity. According to our study, a 1 cm resection is sufficient for a non-extended pituitary tumor extraction. More extensive septal resections allow for better maneuverability and overview in the surgical field.

Tips and Tricks to Safely Perform an Endoscopic Endonasal Trans-Sphenoidal Pituitary Surgery: A Surgeon's Checklist

The authors aimed to develop an extensive preoperative checklist of CT scan findings during endoscopic access to the ventral skull base and implement it in clinical practice. A comprehensive literature review was conducted to identify the radiological landmarks crucial to endoscopic skull base surgery. Four electronic databases were searched: PubMed, MEDLINE, EMBASE, and Google Scholar using search terms/keywords such as "radiological landmarks," "endoscopic skull base surgery," "CT scan," "pituitary surgery," "anatomical variations," "internal carotid," "optic nerve," "sphenoid sinus," "pneumatization," "dehiscence," and "protrusion". Inclusion criteria were limited to original articles and systematic reviews published in English, between the years 2000 and 2021, which pertained to the radiological landmarks to be identified during endoscopic skull base surgery. Full-text articles were retrieved and collated into a narrative review focused on a 12-item checklist the authors agreed upon. The mnemonic "O ROAD TO SELLA" was used to represent the checklist and include the following landmarks: Sphenoid Ostium, Sphenoid Rostrum, Onodi cells, Anatomic variations of the sphenoid sinus, Distance between the carotids, Tumor characteristics, Optic nerve dehiscence/protrusion, Septation/insertion of the sphenoid sinus, Entrance to the sellar floor, Lateral recess of the sphenoid sinus, cLinoid process pneumatization, and internal carotid Artery dehiscence/protrusion. The checklist is designed to be used by attending physicians, fellows, and residents and the authors intend to implement it into electronic medical records at the institution's medical center to monitor the outcomes of EEPS after implementation.

Comparison of prophylactic antibiotics for endonasal transsphenoidal surgery using a national inpatient database in Japan

BACKGROUND

The choice of prophylactic antibiotics for use in endonasal transsphenoidal surgery (ETSS) lacks universal standards. This study aimed to investigate the effectiveness of cefazolin, ampicillin and third-generation cephalosporins for preventing postoperative meningitis and secondary outcomes (in-hospital death and the combination of pneumonia and urinary tract infection) in patients who have undergone ETSS.

METHODS

The study used data from the Diagnosis Procedure Combination database in Japan. Data from 10 688 patients who underwent ETSS between April 2016 and March 2021 were included. Matching weight analysis based on propensity scores was conducted to compare the outcomes of patients receiving cefazolin, ampicillin or third-generation cephalosporins as prophylactic antibiotics.

RESULTS

Of the 10 688 patients, 9013, 102 and 1573 received cefazolin, ampicillin and third-generation cephalosporins, respectively. The incidence of postoperative meningitis did not significantly differ between the cefazolin group and the ampicillin group (OR, 1.02; 95% CI, 0.14-7.43) or third-generation cephalosporins group (OR, 0.81; 95% CI, 0.10-6.44). Similarly, in-hospital death and the composite incidence of pneumonia and urinary tract infection did not differ between the cefazolin group and the ampicillin or third-generation cephalosporins group.

CONCLUSIONS

Cefazolin, ampicillin and third-generation cephalosporins as perioperative prophylactic antibiotics for ETSS do not differ significantly in terms of preventing meningitis.

The learning curve for endoscopic endonasal pituitary surgery: a systematic review

Recent literature demonstrates that a learning curve exists for endoscopic pituitary surgery. However, there is significant variability in the way these studies report their outcomes. This study aims to systematically review the literature regarding outcomes for endoscopic pituitary surgery and how this may be related to a surgical learning curve. An electronic search of the databases Medline, Scopus, Embase, Web of Science and Cochrane Library databases was performed and data extracted according 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. Ten articles were included in the review as they examined the following: rates of gross total resection, average operative time, CSF leak rate, visual outcomes, endocrine outcomes and how these results were influenced by surgical experience. We have demonstrated that a learning curve exists for some outcome variables for endoscopic pituitary surgery. However, there is significant heterogeneity in the current body of literature which makes clear comparisons difficult.

Fat enhanced leukocyte-platelet-rich fibrin versus fascia lata in endoscopic reconstruction of CSF leaks

PURPOSE

The aim of this study was to use a new biological active fat enhanced leukocyte-platelet-rich fibrin membrane (L-PRF) for skull base defect reconstruction and compare its validity and reliability with the time-honored fascia lata.

METHODS

This prospective study was conducted on 48 patients with spontaneous CSF leaks who were divided into 2 matched groups by stratified randomization, 24 patients in each group. In group A we performed multilayer repair using fat enhanced L-PRF membrane. In group B we used fascia lata for the multilayer repair. In both groups we enforced the repair with mucosal grafts/flaps.

RESULTS

The two groups were statistically matched for age, sex, intracranial pressure, and site and size of the skull base defect. There was no statistically significant difference between the two groups regarding the outcome of the repair or recurrence of CSF leak during the first postoperative year. Meningitis occurred in one patient in group B and was successfully treated. Another patient in group B developed thigh hematoma which resolved spontaneously.

CONCLUSION

The fat enhanced L-PRF membrane is a valid reliable option in repair of CSF leaks. The membrane is autologous, readily available, easily prepared, and has the advange of including stromal fat, stromal vascular fraction (SVF), and leukocyte-platelet-rich fibrin (L-PRF). The present study showed that fat enhanced L-PRF membrane is stable, non-absorbable, not liable to shrink or become necrotic, and can establish good seal of the skull base defect and further enhance the healing process. The use of the membrane also has the advantage of avoiding thigh incision and possible hematoma formation.

Traumatic iatrogenic dissecting anterior cerebral artery aneurysms: conservative management as a therapeutic option

INTRODUCTION

Traumatic iatrogenic intracranial aneurysms (TICAs) are rare, but are important due to their risk of intracranial hemorrhage and complexity of management.

METHODS

Two adult patients, one with history of chronic sinusitis and nasal cavity polyposis undergoing functional endoscopic sinus surgery (FESS), and second during rhinoplasty, suffered subarachnoid hemorrhage (SAH) due to anterior cerebral artery (ACA) injury during the procedures.

RESULTS

Two women patients aged 17 and 38 years with SAH after nasal surgery were referred to our institute. Three small dissecting aneurysms were seen involving A2 segment of ACA of two patients. Both were managed conservatively. Follow-up angiography (after 2 months) demonstrated complete occlusion of the aneurysms. There was no rebleeding and the patients had a good outcome at the last follow-up.

CONCLUSIONS

Conservative management of traumatic iatrogenic dissecting cerebral aneurysms is a reasonable therapeutic option that can lead to favorable angiographic and clinical outcomes.

Endoscopic Orientation of Juxta-pituitary Carotid in Transsphenoidal Approaches: Critical Considerations for Clinical Applications

Introduction  In sphenoid sinuses with ill-defined carotid bony landmarks, accidental injury of the internal carotid artery (ICA) remains one of the most challenging complications, which is particularly reported in the endoscopic endonasal transsphenoidal approaches (EETAs). Objectives  To describe an anatomical model for the endoscopic orientation of the juxta-pituitary segment of the ICA in relation to the lateral opticocarotid recess (OCR) as a nearby bony landmark. Methods  Dissection was performed progressively, simulating the EETA, in twenty fresh adult cadavers. After reducing the posterior and lateral walls of the sphenoid sinuses, various measurements were taken from both lateral OCRs to "contact points" on the juxta-pituitary segment of the ICA and lateral margins of the pituitary gland. Results  The current results have enabled us to divide the region between the lateral OCRs into 3 compartments: 2 lateral parasellar compartments contain juxta-pituitary segments of the ICA with a mean width of 8 mm and a narrow range from 7 mm to 10 mm; and a central intercarotid sellar compartment represents the safe region for bone drilling, showing widely variable widths ranging from 9 mm to 20mm. In all specimens, the variation in the width of the intercarotid compartment correlated with the distance between both lateral OCRs. Conclusion  The present study improves surgeon awareness of the variations in the course of the ICA through the EETA along sphenoid sinuses with ill-defined bony landmarks. An appreciation of the measurements taken in the present study can help in operative training, and can also provide a base for future studies to confirm ICA courses associated with a higher risk of injury.

Formal Closure of Endoscopic Endonasal Skull Base Defects With a "Bow Tie" Tri-Layer Graft

OBJECTIVE

Risk factors for a postoperative cerebrospinal fluid leak (CSF) after surgery include an intraoperative high flow of CSF, elevated body mass index, defect size, and defect site. In our prior series, a high postoperative CSF leak rate for tumors of the central skull base (planum, sella, and clivus) appeared to be due to graft migration. We changed our closure technique from a single layer of collagen +/- fat graft to a novel graft, termed a "Bow tie" (a tri-layer fat graft with two pieces of collagen matrix), and report our results in this study.

METHODS

Retrospective temporal epoch study of a single otolaryngologist's experience of closing skull base defects in our skull base center from 2005 to 2017.

RESULTS

One hundred and forty-nine patients met inclusion criteria in two time periods, pre- and post-introduction of the Bow tie technique. In epoch I, from 2005 to 2013, 79 patients had reconstruction with a single layer of dural graft (25 had additional free fat graft). In epoch II, from 2014 to 2017, 70 patients had reconstruction with the Bow tie.

RESULTS

CSF leak rates were 8.7% overall: 15.2% in epoch I and 1.4% in epoch II (p = 0.01). After controlling the procedure, defects with a size greater than 2 cm had a 5.7 greater likelihood of failure. Epoch II had a lower incidence of major complications.

CONCLUSION

Using a single surgeon's experience, the multilayer Bow tie has a significant reduction in postoperative CSF leak and associated major complications for defects of the central skull base.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1568-1575, 2023.

The Transcaruncular Corridor of the Medial Transorbital Approach to the Frontal Lobe: Technical Nuances and Applications

BACKGROUND AND IMPORTANCE

Medial orbital access through a transcaruncular corridor has yet to be fully characterized as a potential approach to intradural lesions within the skull base. Transorbital approaches present unique potential in the management of complex neurological pathologies and require subspecialty collaboration across multiple disciplines.

CLINICAL PRESENTATION

A 62-year-old man presented with progressive confusion and mild left-sided weakness. He was found to have a right frontal lobe mass with significant vasogenic edema. A comprehensive systemic workup was otherwise unremarkable. A multidisciplinary skull base tumor board conference recommended a medial transorbital approach through transcaruncular corridor, which was performed by neurosurgery and oculoplastics services. Postoperative imaging demonstrated gross total resection of the right frontal lobe mass. Histopathologic evaluation was consistent with amelanotic melanoma with BRAF (V600E) mutation. At his last follow-up visit, 3 months after surgery, the patient did not experience any visual symptoms and had an excellent cosmetic outcome after surgery.

CONCLUSION

The transcaruncular corridor through a medial transorbital approach provides a safe and reliable access to the anterior cranial fossa.

Surgical Anatomy and Approaches of the Anterior Cranial Fossa from a Transcranial and Endonasal Perspective

The anterior cranial fossa (ACF) is a complex anatomical region that can be affected by a broad spectrum of pathology. For the surgical treatment of these lesions, many approaches have been described, each of them with different scope and potential surgical complications, often associated with significant morbidity. Traditionally, tumors involving the ACF have been operated by transcranial approaches; however, in the last two decades, endoscopic endonasal approaches (EEAs) have been gaining popularity. In this work, the authors review and describe the anatomical aspects of the ACF and the technical nuances of transcranial and endoscopic approaches for tumors located in this region. Four approaches were performed in embalmed cadaveric specimens and the key steps were documented. Four illustrative cases of ACF tumors were selected to demonstrate the clinical application of anatomical and technical knowledge, which are essential in the preoperative decision-making process.

Endoscopic Endonasal Approach in Craniopharyngiomas: Representative Cases and Technical Nuances for the Young Neurosurgeon

Craniopharyngiomas (CPs) are Rathke's cleft-derived benign tumors originating most commonly in the dorsum sellae and representing 2% of intracranial neoplasms. CPs represent one of the more complex intracranial tumors due to their invasive nature, encasing neurovascular structures of the sellar and parasellar regions, making its resection a major challenge for the neurosurgeon with important postoperative morbidity. Nowadays, an endoscopic endonasal approach (EEA) provides an "easier" way for CPs resection allowing a direct route to the tumor with direct visualization of the surrounding structures, diminishing inadvertent injuries, and providing a better outcome for the patient. In this article, we include a comprehensive description of the EEA technique and nuances in CPs resection, including three illustrated clinical cases.

Management of recurrent cerebrospinal fluid leak, current practices and open challenges. A systematic literature review

Cerebrospinal fluid leak (CSFL) is a rare pathological condition which requires prompt and adequate management due to the high rate of associated major complications. At present, CSFL can be successfully treated through endoscopic endonasal approaches with success rates higher than 90%. Despite this, CSFL recurrence may occur, and its management is critical and still represents a matter of debate. A systematic review of the literature on the management of recurrent CSFL was conducted. It included a cohort of 1,083 cases of CSFL treated with surgical or conservative approaches; 112 cases of recurrence were reported for an overall recurrence rate of 10.3%. Most of the leaks were localised in the anterior skull base (68.3%) and identification of recurrent CSFL may be troublesome. Therefore, the entire skull base must be meticulously examined and long-term follow-up is mandatory. The risk for CSFL recurrence is higher in patients affected by idiopathic intracranial hypertension (IIH), but its role in CSFL recurrence is yet to be understood. Recurrent CSFL must be repaired as soon as possible in order to reduce the risk of intracranial complications. The use of early post-operative CSF diversion by lumbar drain (LD) is currently a matter of debate even in case of CSFL recurrences.

Cadaver Homologous Banked Fascia Lata in Skull Base Reconstruction: Preliminary Multidisciplinary Experiences

Skull base reconstruction has been a widely debated issue. Both autologous and heterologous materials have been proposed, however the formers are usually preferred due to their optimal healing outcomes and integration. Nevertheless they are still associated with donor-site functional and aesthetic morbidity. The aim of this study is to report a preliminary experience of different sites defects skull base repair with Cadaver homologous banked fascia lata graft. Patients who underwent reconstruction of skull base defects with Cadaver homologous banked fascia lata between January 2020 until July 2021 were included in the study. Three patients were finally identified for the study. Patient 1 underwent combined craniotomic-endoscopic surgical access for extended anterior skull base neoplasm with subsequent repair with homologous cadaver fascia lata. Patient 2 underwent endoscopic transphenoidal surgery for sellar-parasellar neoplasm. After tumor debulking the surgical cavity was obliterated with homologous cadaver fascia lata. Patient 3 finally had politrauma with otic capsule-violating fracture with profused CSF leak. An endoscopic obliteration of external and middle ear was performed using homologous cadaver fascia lata with blind sac closure of external auditory canal. No graft displacement or reabsorption was observed in these patients at the last follow-up. Cadaver homologous banked fascia lata has proved safety, efficacy and ductility in reconstruction of different skull base defects. Level of Evidence: Level IV-retrospective cohort study.

Strategy of skull base reconstruction after endoscopic transnasal pituitary adenoma resection

Objective

Endoscopic endonasal surgery (EES) is commonly performed for resection of lesions of the anterior/middle cranial fossa region. Cerebrospinal fluid (CSF) leakage is a major complication. Skull base reconstruction after EES is challenging. We describe our reconstruction strategy and technique and analyze its outcomes.

Methods

We retrospectively analyzed 703 patients with pituitary adenoma who underwent EES in our center from January 2020 to August 2022. Clinical, imaging, operative, and pathologic data were recorded from the medical records and analyzed. Skull base reconstruction was performed to achieve the following three goals: seal the original leak, eliminate dead space, provide blood supply, and early ambulation. Reconstruction was tailored to individual patients based on grade of CSF leakage encountered during surgery.

Results

The number of patients with a grade 0, 1, 2, and 3 intraoperative CSF leak was 487, 101, 86, and 29, respectively. Overall incidence of postoperative CSF leakage was 0.14% (1/703). Fascia sutured and vascularized nasoseptal flap were selected for all grade 3 CSF leaks. One patient who experienced postoperative CSF leakage developed intracranial infection and were treated with lumbar CSF drainage that failed; eventually re-exploration surgery for repair was required. Other patients did not have complications such as CSF leak and infection. 29 patients with grade 3 CSF leakage did not complain of severe nasal complications after operation. No perioperative complications related to the strategy (overpacking, infections, or hematomas) occurred. Incidence of postoperative CSF leak according to intraoperative leak grade was as follows: grade 0, zero; grade 1, zero; grade 2, 1.16% (1/86); and grade 3, zero.

Conclusion

The principles of sealing the original leak, eliminating dead space, providing blood supply, and early ambulation are key in skull base reconstruction after EES. Individualization of these principles can significantly reduce the incidence of postoperative CSF leakage and intracranial infection and reduce the use of lumbar CSF drainage. Skull base suture technique is safe and effective in patients with high-flow cerebrospinal fluid leaks.

Endonasal skull base repair with a vascularised pedicled temporo-parietal myo-fascial flap

Objective

Expanded endonasal approaches (EEAs) to the skull base have increased the scope and extent of pathologies that can be treated endoscopically. The trade-off is creation of large skull base bone defects requiring reconstruction to re-establish barriers between the sino-nasal mucosa and subarachnoid space to prevent CSF leak and infection. A popular reconstructive technique is the local vascularized pedicled naso-septal flap, an option that may not always be possible when there is disruption of the vascular pedicle from multiple previous surgeries, adjuvant radiotherapy or extensive tumor infiltration. An alternative is the regional temporo-parietal fascial flap (TPFF) transposed via the trans-pterygoid route. We implemented a modification of this technique incorporating contralateral temporalis muscle at the tip of this flap and deeper vascularised pericranial layers within the pedicle to provide a more robust flap in selected cases.

Study design/methods

A retrospective review of two cases is presented with both patients having undergone multiple EEAs to resect skull base tumors with adjuvant radiotherapy, their postoperative courses complicated by recalcitrant CSF leaks resistant to multiple surgeries.

Results

Our patients had their persistent CSF fistulae repaired using infra-temporal transposition of the TPFF modified to include some of the contralateral temporalis muscle with optimisation of a vascular pedicle: a temporo-parietal temporalis myo-fascial flap (TPTMFF). Both CSF leaks resolved without further complication.

Conclusion

In situations where local flap repair to reconstruct skull-base defects following EEA may not be viable or has failed, a modified regional flap incorporating temporo-parietal fascia with a preserved vascular pedicle along with attached temporalis muscle plug may provide a robust alternative option.

Evolution of Radiographic Changes of a Vascularized Pedicled Nasoseptal Flap after Endonasal Endoscopic Skull Base Surgery

BACKGROUND AND PURPOSE

There is active research involving the radiographic appearance of the skull base following reconstruction. The purpose of this study was to describe the radiographic appearance of the vascularized pedicle nasoseptal flap after endoscopic skull base surgery across time.

MATERIALS AND METHODS

We performed chart and imaging review of all patients with intraoperative nasoseptal flap placement during endoscopic skull base surgery at a tertiary academic skull base surgery program between July 2018 and March 2021. All patients underwent immediate and delayed (>3 months) postoperative MR imaging. Primary outcome variables included flap and pedicle enhancement, flap thickness, and flap adherence to the skull base.

RESULTS

Sixty-eight patients were included. Flap (P = .003) enhancement significantly increased with time. Mean nasoseptal flap thickness on immediate and delayed postoperative scans was 3.8 and 3.9 mm, respectively (P = .181). The nasoseptal flap adhered entirely to the skull base in 37 (54.4%) and 67 (98.5%) patients on immediate and delayed imaging, respectively (P < .001).

CONCLUSIONS

Our findings demonstrate heterogeneity of the nasoseptal flap appearance after skull base reconstruction. While it is important for surgeons and radiologists to evaluate variations in flap appearance, the absence of enhancement and lack of adherence to the skull base on immediate postoperative imaging do not appear to predict reconstructive success and healing, with many flaps "self-adjusting" with time.

Multiportal Combined Endoscopic Endonasal and Transorbital Pathways: Qualitative and Quantitative Anatomic Studies of the "Connection" Skull Base Areas

BACKGROUND

Combined endonasal and transorbital multiportal surgery has been recently described for selected skull base pathologies. Nevertheless, a detailed anatomic description and a quantitative comprehensive anatomic study of the skull base areas where these 2 endoscopic routes converge, a so-called connection areas, are missing in the scientific literature.

OBJECTIVE

To identify all the skull base areas and anatomic structures where endonasal and transorbital endoscopic avenues could be connected and combined.

METHODS

Five cadaveric specimens (10 sides) were used for dissection. Qualitative description and quantitative analysis of each connection areas were performed.

RESULTS

At the anterior cranial fossa, the connection area was found at the level of the sphenoid planum; in the middle cranial fossa, it was at the Mullan triangle; finally, in the posterior cranial fossa, the connection area was just behind the medial portion of the petrous apex. The average extradural working areas through the transorbital approach were 4.93, 12.93, and 1.93 cm 2 and from the endonasal corridor were 7.75, 10.45, and 7.48 cm 2 at the level of anterior, middle, and posterior cranial fossae, respectively.

CONCLUSION

The combined endonasal and transorbital endoscopic approach is an innovative entity of skull base neurosurgery. From the anatomic point of view, our study demonstrated the feasibility of this combined approach to access the entire skull base, by both corridors, identifying a working connection area in each cranial fossa. These data could be extremely useful during the surgical planning to predict which portion of a lesion could be removed through each route and to optimize patients' care.

Endoscopic Reconstruction of the Anterior Skull Base Following Tumor Resection: Application of a Novel Bioabsorbable Plate

OBJECTIVE

Endoscopic repair of skull base defects is required following resection of intracranial pathology via the endoscopic endonasal approach (EEA). Many closure techniques have been described, but choosing between techniques remains controversial. We report outcomes of 560 EEA procedures of skull base reconstruction performed on 508 patients over a 15-year-period. Halfway through this period, we adopted the use of a rigid, bioabsorbable extrasellar plate for reconstruction, enabling a comparison between this technique and those used previously.

METHODS

All patients undergoing EEA from 2005 to 2019 at our institution were retrospectively reviewed. Demographic information, surgical pathology, tumor dimensions and radiographic features, reconstructive technique, and patient-related outcomes were collected and analyzed with univariate and multivariate statistical modeling.

RESULTS

Five-hundred sixty procedures were performed on 508 patients. The series complication rate was 8.2%. Overall, cerebrospinal fluid (CSF) leak rate was 5.0% but varied significantly across closure techniques (p < 0.001). Critically, the CSF leak rate in the 272 cases prior to our 2013 adoption of the Resorb-X Plate (RXP) was 8.5%, whereas leak rate in the subsequent 288 cases was 1.7%. RXP was protective against CSF leak (p = 0.001), whereas gross total resection (GTR) correlated with increased leak rate (p = 0.001). Patient BMI was significantly associated with risk of leak (p = 0.047). Other variables did not impact leak risk.

CONCLUSION

Reconstructive technique, extent of resection, and patient BMI significantly contributed to CSF leak rate. GTR was associated with increased leak risk while the RXP was protective. The bioabsorbable RXP is an effective option for rigid skull base repair with comparatively few complications.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1092-1098, 2023.

Endonasal Exposure of Lateral Recess of the Sphenoid Sinus: Significance of Pterygoid Process Pneumatization

Background

Caudal pneumatization of the pterygoid process may impact endonasal exposure of the lateral recess of sphenoid sinus (LRSS).

Objectives

This study aims to explore the implications of a pneumatized pterygoid process for an endonasal transpterygoid approach to the LRSS and to define strategies regarding the preservation or sacrifice of the vidian nerve.

Methods

Dissection of the LRSS (11 sides) was performed on 6 cadaveric specimens, preselected for the radiographic presence of an LRSS. In addition, the dimensions of the LRSS were measured on the deidentified CT images of 120 patients (240 sides). The sphenoid sinus was subdivided into 3 categories: Type 1 (no identifiable LRSS), Type 2 (lateral pneumatization of the greater wing above the vidian canal), and Type 3 (pneumatization of both the greater wing and the pterygoid process).

Results

On the cadaveric specimens, a Type 2 pneumatization often allowed access to the LRSS above the level of the vidian canal; thus, sparing the vidian neurovascular bundle. In Type 3 pneumatization, a frontal corridor through the pterygoid base could be created to reach the LRSS with preservation of the vidian nerve. Extreme Type 3 pneumatization, however, required the transposition or sacrifice of the vidian nerve to facilitate a full direct access to the superolateral LRSS. Measurements on CT images revealed that the extent of caudal pneumatization of the pterygoid process had no statistically significant correlation with the superolateral extension of the lateral recess in patients with Type 3 LRSS ( P > .05).

Conclusion

Pneumatization of the LRSS toward a caudal or superolateral direction may develop independent from each other. Caudal pneumatization of the pterygoid process seems to variably impact the endonasal exposure of the LRSS.

Cirugía endoscópica transnasal de base de cráneo: Análisis de las complicaciones en los primeros 120 procedimientos

Antecedentes:

El abordaje endoscópico endonasal (AEE) presenta ventajas potenciales a los abordajes abiertos tradicionales. Sin embargo, se han descrito complicaciones como la fístula de líquido cefalorraquídeo (LCR), trastornos visuales y meningitis postquirúrgica. El objetivo de este trabajo es presentar la experiencia acumulada en 120 casos de cirugía endoscópica de base de cráneo realizadas por un mismo equipo quirúrgico, y describir y analizar las principales complicaciones postoperatorias según la complejidad de los casos.

Métodos:

Estudio retrospectivo sobre nuestra base de datos de pacientes operados de AEE de base de cráneo por diversas patologías entre julio de 2011 y marzo de 2022.

Resultados:

Se analizaron 120 cirugías con AEE de base de cráneo. El 57.14% fueron realizadas en mujeres. La mediana de edad fue de 44 años. El 26.66% fueron reintervenciones. La patología más frecuente fue el adenoma hipofisario (49.17%) seguida de la fístula de LCR (8.33%). El AEE más utilizado fue el transelar 65.83%. Se registraron 26 complicaciones, sin diferencias según la complejidad. Se constataron 13 casos de diabetes insípida (DI) y 8 de fístula de LCR. Esta fue más frecuente en pacientes con fístula intraoperatoria de LCR. La mediana de internación fue de 5.5 días.

Conclusiones:

El AEE de base de cráneo se ha vuelto una opción cada vez más utilizada para el manejo quirúrgico de la patología de la base de cráneo, con una baja frecuencia de complicaciones postoperatorias inmediatas y baja mortalidad. El perfeccionamiento de la técnica como la mejoría en los cuidados postoperatorios se asocian a una menor estancia hospitalaria.

Giant Non-Functioning Pituitary Adenomas: Treatment Considerations

Giant pituitary adenomas are a subgroup of pituitary adenomas defined by a diameter greater than 4 cm, and they account for 5-14% of adenomas in surgical series. Because of their growth patterns and locations, often involving critical neurovascular structures, they represent a true surgical challenge, and gross total resection is difficult to achieve. There is no consensus on the optimal surgical strategy for giant pituitary adenomas, and, often, integrated multi-staged treatment strategies have been considered. Transcranial or transsphenoidal approaches, alone or combined, according to tumor and patient features are the two main routes. Each of these strategies has pros and cons. The conventional transcranial approach has for a long time been considered the first choice for the removal of giant pituitary adenomas. Currently, with endoscopic techniques, it is also possible to remove lesions that involve the intradural compartment and the adjacent neurovascular structures with the use of extended approaches. Our policy for the management of these lesions is to adopt the endoscopic endonasal approach as the first choice unless the tumor presents significant intracranial extension that results in it being outside the visibility and maneuverability of the endoscopic endonasal route. In these latter cases, we agree that the transcranial approach is more appropriate. However, accurate preoperative evaluation and refined treatment plans for each patient are mandatory to define a proper strategy in order to achieve the most effective long-term result.

Exploration of the causes of cerebrospinal fluid leakage after endoscopic endonasal surgery for sellar and suprasellar lesions and analysis of risk factors

Objective

Postoperative cerebrospinal fluid (CSF) leakage following endoscopic endonasal surgery (EES) is a frequent complication. This study aims to identify potential risk factors of postoperative CSF leakage.

Methods

A retrospective review of 360 patients who underwent EES was included. The associations between postoperative CSF leakage and patient demographics, medical history, tumor characteristics, and intraoperative repair techniques were analyzed; the diagnosis and repair of postoperative CSF leakage were also introduced.

Results

Postoperative CSF leakage occurred in 14 patients (3.9%), 2 of them cured by lumbar cistern drainage, 12 underwent endoscopic repair. Among these 12 cases, 3 were repaired twice, and the rest were cured the first time. During the repair surgery, insufficient embedded fat was detected in one case detected, seven with breached inner artificial dura, three had vascularized pedicle nasoseptal flap (VP-NSF) displacement, two with VP-NSF perforation, two with VP-NSF inactivation, and one with imperfect adherence to VP-NSF to the skull base. Eight cases had intracranial infections. Excluding one case who died of severe intracranial infection, the rest were cured and discharged without obvious sequelae. Multivariate analysis revealed that the suprasellar lesion, subarachnoid invasion, and intraoperative grade 3 flow CSF leakage were the risk factors of CSF leakage after operation, while the bone flap was a protective factor.

Conclusion

Bone flap combined with VP-NSF and iodoform gauze for skull base reconstruction is recommended in high-risk patients, while postoperative lumbar cistern drain remains dispensable.

Endoscopic transorbital avenue to the skull base: Four-step conceptual analysis of the anatomic journey

Background

In the last decades, skull base surgery had passed through an impressive evolution. The role of neuroanatomic research has been uppermost, and it has played a central role in the development of novel techniques directed to the skull base. Indeed, the deep and comprehensive study of skull base anatomy has been one of the keys of success of the endoscopic endonasal approach to the skull base. In the same way, dedicated efforts expended in the anatomic lab has been a powerful force for the growth of the endoscopic transorbital approach to the lateral skull base.

Therefore, in this conceptual paper, the main steps for the anatomic description of the endoscopic transorbital approach to the skull base have been detailed.

Methods

The anatomic journey for the development of the endoscopic transorbital approach to the skull base has been analyzed, and four “conceptual” steps have been highlighted.

Results

As neurosurgeons, the eyeball has always represented a respectful area: to become familiar with this complex and delicate anatomy, we started by examining the orbital anatomy on a dry skull (step 1). Hence, step 1 is represented by a detailed bone study; step 2 is centered on cadaveric dissection; step 3 consists in 3D quantitative assessment of the novel endoscopic transorbital corridor; and finally, step 4 is the translation of the preclinical data in the real surgical scenario by means of dedicated surgical planning.

Conclusions

The conceptual analysis of the anatomic journey for the description of the endoscopic transorbital approach to the skull base resulted in four main methodological steps that should not be thought strictly consequential but rather interconnected. Indeed, such steps should evolve following the drives that can arise in each specific situation. In conclusion, the four-step anatomic rehearsal can be relevant for the description, diffusion, and development of a novel technique in order to facilitate the application of the endoscopic transorbital approach to the skull base in a real surgical scenario.

Evolution in endoscopic endonasal approach for the management of hypothalamic–pituitary region metastasis: A single-institution experience

Introduction

Endonasal endoscopic surgery has changed the treatment perspectives for different lesions of the hypothalamic–pituitary region. The metastases of the hypothalamic–pituitary region represent 0.4% of all intracranial metastatic tumors and account for only 1.8% of surgically managed pituitary lesions. The aim of tshis study is to describe a single-center institutional experience with 13 cases of hypothalamic–pituitary metastasis focused on presurgical workup, the evolution of the surgical technique, and postsurgical management according to our protocols, showing effects on progression-free and overall survival rates for this relatively uncommon location.

Material and Methods

We retrospectively reviewed the whole series of patients that received the endoscopic endonasal approach at the Division of Neurosurgery at the University of Naples “Federico II” undergoing surgery from January 1997 to December 2021. We identified 13 cases whose pathology reports revealed a metastatic lesion. Statistical analysis was performed to determine the Kaplan–Meier survival function and assess for log-rank differences in survival based on gender, surgical treatment, and postoperative therapy (p-value &lt; 0.02*).

Results

The pathology report disclosed lung adenocarcinoma (six cases, 46%), breast adenocarcinoma (two cases, 15.4%), clear cell renal carcinoma (one case, 7%), melanoma (one case, 7%), colorectal adenocarcinoma (one case, 7%), uterine cervix carcinoma (one case, 7%), and follicular thyroid carcinoma (one case, 7%). A standard endoscopic endonasal approach was performed in 10 patients (76.9%), while an extended endonasal procedure was performed in only three cases (23%). Biopsy was the surgical choice in five patients with infiltrative and invasive lesions and a poor performance status (38%), while in the cases where neurovascular decompression was necessary, a subtotal resection was achieved in five patients (38%) and partial resection in three patients (23%). Recovery of visual field defect was observed in six of seven patients with visual loss (85.7%), improvement of oculomotor nerve palsy occurred in four of seven patients with this defect (57.1%), while the impairment of oculomotor palsy was observed in three patients (42.9%). Visual function was stable in the other patients. The median progression-free survival and overall survival were 14 and 18 months, respectively. There were statistically significant differences in PFS and OS in patients who underwent adjuvant radiotherapy (p=0.019 is referred to OS and p=0.017 to PFS, respectively; p-value = 0.02).

Conclusions

The endoscopic endonasal approach is a viable approach for the management of hypothalamic–pituitary metastases as this surgery provides an adequate opportunity to obtain tissue sample and neurovascular decompression, both being crucial for continuing the integrated adjuvant therapy protocols.

Effects of cruciate embedding fascia-bone flap technique on grade II-III cerebral spinal fluid leak in endoscopic endonasal surgery

Background

Cerebral spinal fluid (CSF) leak remains an important issue in endoscopic endonasal surgery (EES). A standard protocol for skull base closure has not yet been established, and the application of rigid buttress has not been given sufficient attention. To emphasize the functions of support and fixation from rigid buttress in reconstruction, we introduced the cruciate embedding fascia-bone flap (CEFB) technique using autologous bone graft to buttress the fascia lata attachment to the partially sutured skull base dural defect and evaluated its efficacy in a consecutive case series of grade II–III CSF leaks in EES.

Methods

Data from consecutive patients diagnosed with sellar region lesions with grade II–III CSF leaks during EES were collected from May 2015 to May 2020. Skull base reconstructions were performed with the CEFB or the conventional pedicle vascularized nasoseptal flap (PNSF). Related clinical data were analysed. The combined use of the CEFB and PNSF was applied to an additional supplemental case series of patients with grade III leak and multiple high-risk factors.

Results

There were 110 and 65 patients included in the CEFB and PNSF groups, respectively. The CEFB demonstrated similar effects on the incidence of postoperative CSF leak (2.7%), intracranial infection (4.5%), and lumbar drainage (LD) placement (5.5%) as PNSF (3.1%, 3.1%, and 6.2%), but with less epistaxis (CEFB: 0%, PNSF: 6.2%) and nasal discomforts (CEFB: 0%, PNSF: 7.7%). The LD duration (CEFB: 6.67 ± 2.16 days, PNSF: 10.50 ± 2.38 days), bed-stay time (CEFB: 5.74 ± 1.58 days, PNSF: 8.83 ± 3.78 days) and hospitalization time (CEFB: 10.49 ± 5.51 days, PNSF: 13.58 ± 5.50 days) were shortened in the CEFB group. The combined use of CEFB and PNSF resulted in 0 postoperative CSF leaks in the supplemental case series of 23 highly susceptible patients.

Conclusion

This study suggested that the new CEFB technique has the potential to prevent postoperative CSF leak in EES. The results indicated that it can be used effectively without PNSF in suitable cases or applied in addition to a PNSF with high compatibility when necessary. Its effectiveness should be further verified with a larger cohort and better design in the next step.

Trial Registration Current Controlled Trials ChiCTR2100044764 (Chinese Clinical Trial Registry); date of registration: 27 March 2020. Retrospectively registered

Endonasal access to the lateral poststyloid space: Far lateral extension of an endoscopic endonasal corridor

The styloid process constitutes the posterolateral boundary for an endonasal exposure of the infratemporal fossa. This study aims to explore the feasibility of a far-lateral extension to the lateral poststyloid space via an endonasal corridor. An endonasal dissection was performed on six cadaveric specimens (12 sides). Following an endoscopic endonasal access to the parapharyngeal space, the styloid process and the tympanic portion of the temporal bone were removed to reveal the jugular bulb and the extratemporal facial nerve. Distances from the anterior nasal spine to the relevant landmarks were measured using a surgical navigation device. Through an endonasal corridor, only the anteroinferior aspect of the jugular bulb was exposed. Conversely, the extratemporal facial nerve could be sufficiently exposed, and the deep temporal nerve could be transposed to the stylomastoid foramen. The average horizontal distances from the nasal spine to the posterior tract of V₃ , styloid process, and facial nerve were 79.33 ± 3.41, 97.10 ± 4.74, and 104.77 ± 4.42 mm, respectively. Access to the lateral poststyloid space via an endonasal corridor is feasible, potentially providing an alternative approach to address select lesions extending to this region. The deep temporal nerve has a similar diameter to that of the facial nerve; thus, providing potential reinnervation of the facial nerve.

Three-Dimensional Reconstruction of the Sphenoid Sinus Anatomy for Presurgical Planning with Free OSIRIX Software

Background A preoperative three-dimensional (3D) surgical field understanding remains a key factor to achieve safer endonasal transsphenoidal endoscopic approaches (ETSE). The aim of this article is to describe how we can get a reliable 3D sphenoidal anatomical reconstruction for surgical planning by using a user-friendly, accurate, and free image software.

Methods Free computer software (OSIRIX Medical Imaging Software) was used to create in a personal computer a three-dimensional (3D) reconstruction of the sphenoid sinus (SS) based on head computed tomography angiographies (CTAs) from a series of 67 patients who were operated for sellar tumors during a 4-year period (March 2016 to March 2020). The aim of the 3D reconstruction with OSIRIX was to reveal preoperatively the most important intrasphenoidal structures seen from the endonasal point of view.

Results The intraoperative visible sphenoidal structures were previously recognized in the virtual 3D reconstructed image with 100% of specificity (SP) and positive predictive value. The OSIRIX view by using region of interest points allowed us to see preoperatively the internal carotid artery parasellar course even in those cases in which it was hidden by bone or tumor. Moreover, the 3D reconstruction was able to provide a clear differentiation between the tumor and the pituitary gland when both structures were in contact with the sellar floor.

Conclusion Our experience with the OSIRIX software from CTA as preoperative planning for endonasal pituitary surgery was valuable, because it gave us access in simple way to a free and reliable 3D image of the SS.

Equivalent outcomes in nasal symptoms following microscopic or endoscopic transsphenoidal surgery: results from multi-centre, prospective study

Background

T ranssphenoidal surgery (TSS) is the standard approach for resection of pituitary lesions. Historically, this has utilized the microscopic approach (mTSS); however, the past decade has seen widespread uptake of the endoscopic approach (eTSS). The purported benefits of this include improved visualization and illumination, resulting in improved surgical and endocrinological patient outcomes. It is also believed that eTSS results in fewer post-operative nasal symptoms compared to mTSS; however, few papers have directly compared these groups.

Objectives

We sought to compare nasal symptoms after endoscopic uninostril (eTSS-uni), endoscopic binostril (eTSS-bi) and microscopic endoscopic transsphenoidal surgery (mTSS).

Methods

The General Nasal Patient Inventory (GNPI) was prospectively administered to 136 patients (71 non-functioning adenomas, 26 functioning adenomas, 39 other pathology) undergoing transsphenoidal surgery at multiple time points (pre-operatively; days 1, 3 and 7–14; months 1, 3 and 6 and 1 year post-operatively). All surgeries were performed by subspecialist pituitary surgeons in three subgroups — mTSS (25), eTSS-uni (74) and eTSS-bi (37). The total GNPI scores (0–135) and subscores for the 45 individual components were compared across three groups assessing for temporal and absolute changes.

Results

Irrespective of surgical approach used, GNPI scores were significantly higher on post-operative day 1 (p < 0.001) and day 3 (p ≤ 0.03) compared to pre-treatment baseline (mixed-effects model). By 1 month post-operatively, however, post-operative GNPI scores were no different from pre-treatment (p > 0.05, mixed-effects model). Whilst the eTSS-uni group demonstrated significantly lower GNPI scores at day 1 post-op compared to the mTSS group (p = 0.05) and eTSS-bi group (p < 0.001), there was no significant difference in post-operative scores between approaches beyond 1–2 weeks post-operatively. Similar results were obtained when the non-functioning tumour group was analysed separately.

Conclusions

Transsphenoidal pituitary surgery is well tolerated. Post-operative nasal symptoms transiently worsen but ultimately improve compared to pre-operative baseline. Operative approach (microscopic, endoscopic uninostril or endoscopic binostril) only has a transient effect on severity of post-operative nasal symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-022-05138-5.

Nasoseptal flap and rigid reconstruction in endoscopic endonasal skull base surgeries: The longitudinal experience of a single center

BACKGROUND

Recently, endoscopic endonasal approaches (EEA) have been used for skull base defect reconstruction surgeries. The nasoseptal flap (NSF), a vascular pedicled flap, was introduced to decrease postoperative cerebrospinal fluid (CSF) leakage.

PURPOSES

This study aimed to outline the authors' institutional experience using NSF and rigid implants in anterior skull base defect reconstruction surgeries following EEA.

DESIGN

A retrospective cohort review of patients who underwent NSF reconstruction following EEA in the Otorhinolaryngology and Neurosurgery Departments at King Saud University Medical City, Riyadh, Saudi Arabia, from January 2015 to May 2021, divided into 2 time periods according to the reconstruction technique.

RESULT

Out of the 106 patients who underwent EEA, 77 underwent NSF reconstruction. The majority had expanded EEA (94.8%). The mean age was 40.21 ± 17.7 years, and the female gender represented 61% of the sample. More than half of the sample underwent right NSF (57.1%). Meningioma was the most common diagnosis (45.5%). The clivus was the most frequent site of lesions (23.4%). The overall rate of postoperative CSF leakage and lumbar drainage (LD) insertion was 15.6% and 51.9%, respectively. The duration of LD was a median of four days. The overall failure rate was 13%, declining from 20% in the first period to 5.4% in the second period. Rigid implants were used significantly more in the first period than in the second period (67.5% versus 16.2%, P < 0.001). Meningitis, the highest postoperative complication, was reported in 6 patients (7.8%). One patient died three weeks postoperatively after massive nasal bleeding. No significant difference was found between either side of the NFS regarding the CSF leakage and failure rate.

CONCLUSION

In the authors' experience, there has been an overt decline in failure rates and complications of EEA over the last three years due to increased experience among surgeons and a standardization of reconstruction techniques. Minimal reconstruction may provide satisfactory results by decreasing the use of rigid implants. An endoscopic endonasal approach with an NSF for anterior skull base defect reconstruction is considered a safe procedure with no significant difference between the sides of the flap.

Injury to the Extrasellar Portion of the Internal Carotid Artery during Endoscopic Transsphenoidal Surgery: A Case Report

Background

Injury to the internal carotid artery (ICA) during endoscopic transsphenoidal surgery (ETSS) is a serious complication with a risk of mortality. ICA injury during ETSS usually occurs during intrasellar manipulations and rarely occurs in the extrasellar portion. Several hemostatic procedures have been proposed for ICA injury in the intrasellar portion, whereas hemostatic methods for ICA injury in the extrasellar portion, where the ICA is surrounded by bone structures, are less well known.

Case Presentation

A 65-year-old man with an incidental pituitary tumor underwent ETSS. The petrous portion of the left ICA was injured during resection of the sphenoid septum connected with left carotid prominence using a cutting forceps. Bleeding was too heavy for simple hemostatic techniques. Hemostasis using a crushed muscle patch was tried unsuccessfully during controlling of the bleeding. Eventually, the injured site of the ICA was covered with cotton patties followed by closing with a vascularized pedicled nasoseptal flap. Cerebral angiography immediately after surgery showed no extravasation from the injured site of the left ICA petrous portion. However, a carotid-cavernous sinus fistula originating from the injured ICA site was detected 7 days after surgery, so the vascular reconstructive surgery combined with left ICA occlusion was performed. The overall postoperative course was uneventful.

Conclusion

We believe that emergency application of the cottonoids may be effective for hemostasis against ICA injury in the extrasellar portion during ETSS, but further vascular reconstruction combined with ICA occlusion on the injured side and removal of the cottonoids would be required.

Visual deterioration after endonasal endoscopic skull base surgery: causes, treatments, and outcomes

OBJECTIVE

Visual deterioration after endoscopic endonasal transsphenoidal surgery (EETS) for sellar and parasellar masses is a rare but serious complication caused by either compressive or ischemic mechanisms. Timely diagnosis and intervention may restore vision if instituted appropriately. The associated risk factors and their relation to the success of intervention are not well understood.

METHODS

The authors examined a series of 1200 consecutive EETS cases performed by the senior author at Weill Cornell/NewYork-Presbyterian Hospital from 2010 to 2020. Cases with postoperative visual deterioration were identified. Pre- and postoperative clinical data, mechanism of visual decline, latency to intervention, and long-term visual outcome were retrospectively collected and analyzed with appropriate statistical methods.

RESULTS

Twenty-one patients (1.75%) complained of early postoperative visual deterioration. The most common pathology associated with postoperative visual loss was craniopharyngioma (7.69%), followed by meningioma (5.43%) and then pituitary adenoma (1.94%). Timely intervention restored vision in 81% of patients for a 0.33% rate of permanent visual deterioration. Average time to visual deterioration was 28.8 hours, and over 70% of patients experienced vision loss within the first 13 hours. Compressive etiology (n = 11), consisting of either hematoma (n = 8) or graft displacement (n = 3), occurred 7.3 hours and 70.3 hours after surgery, respectively, and was more common in adenomas. Acute postoperative visual deterioration was more common in firm closures (4.78%) compared with soft closures (1.03%; p = 0.0006). Ischemic etiology (n = 10) occurred 10.3 hours after surgery and was more common with craniopharyngiomas and meningiomas (p = 0.08). Sixteen patients (76.2%) underwent early reoperation to explore and decompress the optic apparatus. Vision was restored to baseline after reoperation in all 11 compressive cases, whereas 6/10 ischemic cases improved with supplemental oxygen and hypervolemic hypertensive therapy (p = 0.02). Fluid expansion from 8 to 16 hours (p = 0.034) and systolic blood pressure elevation from 32 to 48 hours (p = 0.05) after surgery were significantly higher in those ischemic patients who recovered some vision compared with those with persistent visual deficits.

CONCLUSIONS

Visual deterioration after EETS is a rare event but can be effectively treated if acted upon appropriately and in a timely fashion. Compressive etiology is reversible with early reoperation. Ischemic etiology can be successfully treated in roughly half of cases with supplemental oxygen and hypertensive hypervolemic therapy but may result in permanent visual deterioration if not instituted appropriately or if delayed with unnecessary exploratory surgery.

Functional Outcomes and Quality of Life in Patients with Sinonasal, Nasopharyngeal, and Anterior Skull Base Tumors

PURPOSE OF REVIEW

This article will review functional and QOL outcomes among patients treated predominantly for sinonasal and nasopharyngeal malignancies.

RECENT FINDINGS

Treatment advances and interdisciplinary supportive care help to lessen the functional impairments and the reduction in quality of life (QOL) that were once accepted as inevitable tradeoffs for cure. Recent progress in QOL and Patient-Reported Outcome (PRO) instruments for this population will be covered. Sinonasal and nasopharyngeal tumors affect patients' quality of life, appearance, and critical functions. Tumors arise in proximity of vital structures including the orbit, cranial nerves, carotid artery, brain, cervical spine, and pituitary gland. Surgical morbidity, along with acute and late effects of systemic therapy and radiotherapy on normal tissues in this functionally critical region, may result in wide-ranging symptoms. Patients with skull base tumors report a high symptom burden at presentation, prior to treatment, relative to other malignancies in the head and neck region.

"Sagittal Crest": Definition, Stepwise Dissection, and Clinical Implications From a Transorbital Perspective

BACKGROUND

The recent development of the superior eyelid endoscopic transorbital approach (SETOA) offered a new route for the management of cavernous sinus and middle cranial fossa tumors. As a result, a constant anatomic landmark of the surgical pathway after drilling the medial edge of the greater sphenoid wing (GSW) is represented by a triangular-shaped bone ridge appearing as a "crest."

OBJECTIVE

To perform an anatomic study to define this surgical landmark, named the "sagittal crest" (SC) as seen from the transorbital endoscopic view.

METHODS

Four adult cadaveric specimens (8 sides) were dissected performing an endoscopic transorbital approach to the middle fossa and the SC was removed to perform interdural opening of the cavernous sinus. Computed tomography scans were made before and after removal of the SC to perform quantitative analysis and building a 3-dimensional model of the bone resection of the GSW via the SETOA.

RESULTS

The SC is a bone ridge triangle shaping dorsally the superior orbital fissure resulting as the residual fragment after drilling the lateral aspect of the greater sphenoid wing. Predissection and postdissection computed tomography scans allowed to objectively assess SC features and dimensions (mean 1.08 ± 0.2 cm).

CONCLUSION

The SC is a constant anatomic landmark constituted of the residual medial portion of the GSW. Complete resection of this key landmark provides adequate working space and appears to be mandatory during SETOA to guide the subsequent interdural dissection of the lateral wall of cavernous sinus.

The effects of cerebrospinal fluid (CSF) diversion on post-operative CSF leak following extended endoscopic anterior skull base surgery

There is a paucity of high quality evidence regarding the routine placement of lumbar drain (LD) in reducing post-operative (op) cerebrospinal fluid (CSF) leak after extended endoscopic trans-sphenoidal resection of anterior skull base lesions. In this study, we sought to compare the incidence of post-op CSF leak between patients with upfront LD insertion and those without it. This was a prospective randomized controlled trial conducted over a period of 5 years with patients undergoing extended endoscopic trans-sphenoidal surgery randomly assigned to either LD insertion at the time of surgery, or no LD placement. Thirty-eight patients with anterior skull base tumors were accrued from three tertiary hospitals of Melbourne. Post-op leak was confirmed by β2-transferrin-positive rhinorrhea, and/or worsening pneumocephalus on brain imaging. Skull base defect size and pedicled nasoseptal flap viability were assessed on post-op CT and MRI, respectively. There was no significant difference in post-op CSF leak incidence between the two subgroups (12.50% in LD arm vs. 9.10% in no LD arm). Patients with LD insertion however, demonstrated substantially raised complication rates, longer hospital lengths of stay and lower subjective quality of life measures at 12 months compared with those without LD. In conclusion, routine placement of LD at the time of surgery for extended anterior skull base trans-nasal approach did not reduce the risk of post-op CSF leak. Discretion is warranted when using LD as an adjunct due to its associated morbidities, prolonged hospital stay and adverse effect on patients' subjective outcome measures.