Impact of skull base development on endonasal endoscopic surgical corridors

Comparative Efficacy of Transsphenoidal and Transcranial Approaches for Treating Tuberculum Sellae Meningiomas: A Systematic Review and Meta-Analysis

Background/Objectives: Tuberculum sellae meningiomas (TSMs) constitute 5-10% of intracranial meningiomas, often causing visual impairment. Traditional microsurgical transcranial approaches (MTAs) have been effective, but the emergence of innovative surgical trajectories, such as endoscopic endonasal approaches (EEAs), has sparked debate. While EEAs offer advantages like reduced brain retraction, they are linked to higher cerebrospinal fluid leak (CSF leak) risk. This meta-analysis aims to comprehensively compare the efficacy and safety of EEAs and MTAs for the resection of TSMs, offering insights into their respective outcomes and complications. Methods: A comprehensive literature review of the databases PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted for articles published on TSMs treated with either EEA or MTA until 2024. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Meta-analysis was performed to estimate pooled event rates and assess heterogeneity. Fixed- and random-effects were used to assess 95% confidential intervals (CIs) of presenting symptoms, outcomes, and complications. Results: A total of 291 papers were initially identified, of which 18 studies spanning from 2000 to 2024 met the inclusion criteria. The exclusion of 180 articles was due to reasons such as irrelevance, non-reporting of selected results, systematic literature review or meta-analysis, and a lack of details on method/results. The 18 studies comprised a total sample of 1093 patients: 444 patients who underwent EEAs and 649 patients who underwent MTAs for TSMs. Gross total resection (GTR) rates ranged from 80.9% for EEAs to 79.8% for MTAs. The rate of visual improvement was 86.6% in the EEA group and 65.4% in the MTA group. The recurrence rate in the EEA group was 6.9%, while it was 5.1% in MTA group. The postoperative complications analyzed were CSF leak, infections, dysosmia, intracranial hemorrhage (ICH), and endocrine disorders. The rate of CSF leak was 9.8% in the EEA group and 2.1% in MTA group. The rate of infections in the EEA group was 5.7%, while it was 3.7% in the MTA group. The rate of dysosmia ranged from 10.3% for MTAs to 12.9% for EEAs. The rate of ICH in the EEA group was 0.9%, while that in the MTA group was 3.8%. The rate of endocrine disorders in the EEA group was 10.8%, while that in the MTA group was 10.2%. No significant difference was detected in the rate of GTR between the EEA and MTA groups (OR 1.15, 95% CI 0.7-0.95; p = 0.53), while a significant benefit in visual outcomes was shown in EEAs (OR 3.54, 95% CI 2.2-5.72; p < 0.01). There was no significant variation in the recurrence rate between EEA and MTA groups (OR 0.92, 95% CI 0.19-4.46; p = 0.89). While a considerably increased chance of CSF leak from EEAs was shown (OR 4.47, 95% CI 2.52-7.92; p < 0.01), no significant difference between EEA and MTA groups was detected in the rate of infections (OR 1.92, 95% CI 0.73-5.06; p = 0.15), the rate of dysosmia (OR 1.25, 95% CI 0.31-4.99; p = 0.71), the rate of ICH (OR 0.61, 95% CI 0.20-1.87; p = 0.33), and the rate of endocrine disorders (OR 1.16, 95% CI 0.69-1.95; p = 0.53). Conclusions: This meta-analysis suggests that both EEAs and MTAs are viable options for TSM resection, with distinct advantages and drawbacks. The EEAs demonstrate superior visual outcomes in selected cases while GTR and recurrence rates support the overall effectiveness of MTAs and EEAs. Endoscopic endonasal approaches had a higher chance of CSF leaks, but there are no appreciable variations in other complications. These results provide additional insights regarding patient outcomes in the intricate clinical setting of TSMs.

Special Considerations in Pediatric Endoscopic Skull Base Surgery

Originally pioneered in adults, endoscopic endonasal approaches for skull base pathology are being increasingly applied as a minimally invasive alternative for young children. Intrinsic anatomic differences between these patient populations have sparked discussions on the feasibility, safety, and efficacy of these techniques in pediatric patients. This work aims to serve as a primer for clinicians engaged in the rapidly evolving field of pediatric endoscopic skull base surgery. A succinct overview of relevant embryology, sinonasal anatomy, and diagnostic workup is presented to emphasize key differences and unique technical considerations. Additional discussions regarding select skull base lesions, reconstructive paradigms, potential surgical complications, and postoperative care are also highlighted in the setting of multidisciplinary teams.

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.

Neurosurgical Treatment and Outcome of Pediatric Skull Base Lesions: A Case Series and Review of the Literature

INTRODUCTION

Pediatric skull base lesions occur rarely and are of various etiologies. Traditionally, open craniotomy has been the treatment of choice; however, nowadays, endoscopic approaches are increasingly applied. In this retrospective case series, we describe our experience in treating pediatric skull base lesions and provide a systematic overview of the literature on the treatment and outcome of pediatric skull base lesions.

METHODS

We conducted a retrospective data collection of all pediatric patients (<18 years) treated for a skull base lesion at the Division of Pediatric Neurosurgery, University Children's Hospital Basel, Switzerland, between 2015 and 2021. Descriptive statistics and a systematic review of the available literature were additionally conducted.

RESULTS

We included 17 patients with a mean age of 8.92 (±5.76) years and nine males (52.9%). The most common entity was sellar pathologies (n = 8 47.1%), with craniopharyngioma being the most common pathology (n = 4, 23.5%). Endoscopic approaches, either endonasal transsphenoidal or transventricular, were used in nine (52.9%) cases. Six patients (35.3%) suffered from transient postoperative complications, while in none of the patients these were permanent. Of the nine (52.9%) patients with preoperative deficits, two (11.8%) showed complete recovery and one (5.9%) partial recovery after surgery. After screening 363 articles, we included 16 studies with a total of 807 patients for the systematic review. The most common pathology reported in the literature confirmed our finding of craniopharyngioma (n = 142, 18.0%). The mean PFS amongst all the studies included was 37.73 (95% CI [36.2, 39.2]) months, and the overall weighted complication rate was 40% (95% CI [0.28 to 0.53] with a permanent complication rate of 15% (95% CI [0.08 to 0.27]. Only one study reported an overall survival of their cohort of 68% at five years.

CONCLUSION

This study highlights the rarity and heterogeneity of skull base lesions in the pediatric population. While these pathologies are often benign, achieving GTR is challenging due to the deep localization of the lesions and eloquent adjacent structures, leading to high complication rates. Therefore, skull base lesions in children require an experienced multidisciplinary team to provide optimal care.

Minimally invasive endoscopic approaches to pediatric skull base pathologies

OBJECTIVE

Endoscopic endonasal approaches to pediatric skull base lesions are rare, challenging, and present distinct considerations from adult pathology. In this study, we describe our endoscopic technical approach to various skull base lesions demonstrating the efficacy and nuances of these approaches in pediatric patients.

METHODS

Pediatric patients underwent endoscopic approach for skull base lesions from January of 2015 to April of 2021 were included in the study. Presenting symptoms, indications for surgery, surgical outcomes, intraoperative and postoperative complications, length of hospital stay, and length of follow-up were documented.

RESULTS

A total of 18 patients (median age 12, age-range 1-15, 53% male) underwent 19 endoscopic transsphenoidal procedures. The pathologies included craniopharyngioma (N = 5), biopsy for an unknown disease (n = 2; orbital meningioma and pituitary lymphocytic hypophysitis), pituitary adenoma (N = 2; ACTH-secreting and non-functional), Rathke's cleft cyst (n = 2), CSF leak repairs (n = 2; post-traumatic and spontaneous meningocele), juvenile nasopharyngeal angiofibroma (n = 3, 1 patient had 2 procedures) and rhabdomyosarcoma (n = 1). GTR was achieved in 11 out of 15 procedures (73.3%). Out of 10 patients with a sellar lesion, 6 patients had intraoperative CSF leak (60%). No patients experienced post-operative CSF leak. The median follow-up for all patients was 14 months (1-36 months).

CONCLUSION

Anterior and middle skull base pathology in pediatric patients can be effectively operated via an endoscopic approach across a wide variety of patient ages and conditions. Minimally invasive techniques with middle turbinate and nasal septum preservation can be achieved without compromising outcomes. A wide variety of surgical repair strategies can be successfully utilized.

Complications of Endoscopic Skull Base Surgery for Sellar and Parasellar Tumors in Pediatric Population; Neurosurgical Perspectives

Background

Advances in surgical techniques based on in-depth anatomical knowledge of the skull base have broadened the indications for endoscopic skull base surgery (ESS) with the advantage of wide and direct surgical exposure while minimizing invasiveness. However, the low incidence of the indicated diseases and narrow surgical corridors in children have limited the popularization of ESS. In addition, surgical complications and preventive interventions are not yet well known. Therefore, we retrospectively investigated the complications and prevention methods of ESS in children with a comprehensive review.

Methods

We retrospectively analyzed the medical records of pediatric patients who underwent ESS for sellar and parasellar tumors at Seoul National University Children's Hospital from July 2010 to December 2020. Visual and endocrine status, extent of resection, complications, and recurrences were investigated depending on the pathology of the tumor. In addition, a comprehensive literature review regarding the complications of pediatric ESS was performed.

Results

A total of 98 patients were enrolled. The median age of the patients was 12 years, and 52 patients were male. Preoperative visual disturbance was found in 53 patients, anterior pituitary function deficit in 69, and diabetes insipidus in 32. Gross total resection was attempted in 67 patients and achieved in 62 (93%). Biopsy and cyst fenestration were the goals of surgery in 26 patients, and all were achieved as planned. Regarding outcomes, visual disturbance worsened in two patients (2%), endocrine status was aggravated in 34 (35%) patients, and new-onset diabetes insipidus occurred in 27 (41%) patients. The overall surgical complication rate (other than aggravation of visual or endocrine status) was 17%. Postoperative meningitis (12%) was the most common complication, followed by cerebrospinal fluid leakage (2%), vasospasm, hemorrhage and infarction. By pathological diagnosis, craniopharyngioma had the highest complication rate of 29%. All but one patient with postoperative hemorrhage showed no permanent deficits.

Conclusion

ESS in children is feasible and relatively safe. More attention and different postoperative management protocols are required in children to avoid complications, especially in craniopharyngiomas. However, the complications can be mostly managed conservatively without permanent neurologic deficits.

Anatomic Parameters and Growth of the Pediatric Skull Base: Endonasal Access Implications

Objectives: Endoscopic endonasal anterior skull base surgery has expanding use in the pediatric population, but the anatomy of pediatric patients can lead to limitations. This study aims to characterize the important anatomical implications of the pediatric skull base using computed tomography (CT) scans. Design: Retrospective analysis Setting: Tertiary academic medical center Participants: 506 patients aged 0-18 who had undergone maxillofacial and or head CTs between 2009-2016. Methods: Measurements included piriform aperture width, nare to sella distance (NSD), sphenoid pneumatization, olfactory fossa depth, lateral lamella cribriform plate angles, and intercarotid distances (ICD) at the superior clivus and cavernous sinus. These patients were then subdivided into 3 age groups adjusting for sex. ANCOVA models were fit comparing between all age groups and by sex. Results: Piriform aperture width, NSD, sphenoid sinus pneumatization as measured using lateral aeration and anterior sellar wall thickness, olfactory fossa depth, and ICD at the cavernous sinus was significantly different among all age groups (P<0.0001). Our results show that mean piriform aperture width increased with each age group. The mean olfactory fossa depth also had consistent age dependent growth. In addition, ICD at the cavernous sinus showed age dependent changes. When comparing by sexes, females consistently showed smaller measurements. Conclusion: The process of skull base development is age and sex dependent. During preoperative evaluation of pediatric patients for skull base surgery piriform aperture width, sphenoid pneumatization in both the anterior posterior and lateral directions, and ICD at the cavernous sinus should be carefully reviewed.  

Maturation of the sella turcica and parasellar region: Surgical relevance for anterior skull base approaches in pediatric patients

OBJECTIVE

Traditional and extended transnasal transsphenoidal approaches provide direct access to a variety of anterior skull base pathologies. Despite increased utilization of transnasal approaches in children, anatomic studies on pediatric skull base maturation are limited. We herein perform a surgically relevant morphometric analysis of the sella and parasellar regions during pediatric maturation.

METHODS

Measurements of sellar length (SL), sellar depth (SDp), sellar diameter (SDm), interclinoid distance (ID), intercavernous distance (ICD), and the presence of sphenoid sinus pneumatization (SSP), and sphenoid sinus type (SST) were made on thin-cut CT scans from 60 patients (evenly grouped by ages 0-3, 4-7, 8-11 12-15, 16-18, and >18 years) for analysis. Data were analyzed by sex and age groups using t-tests and linear regression.

RESULTS

Sella and parasellar parameters did not differ by sex. SL steadily increased from 8.5 ± 1.2 mm to 11.5 ± 1.6 mm throughout development. SDp and SDm increased from 6.0 ± 0.9 mm to 9.3 ± 1.4 mm and 9.0 ± 1.6 mm to 14.4 ± 1.8 mm during maturation, with significant interval growth from ages 16-18 to adult (p < 0.01). ID displayed significant growth from ages 0-3 to 4-7 (18.0 ± 2.4 mm to 20.7 ± 1.9 mm; p = 0.002) and ICD from ages 0-3 to 8-11 (12.0 ± 1.8 mm to 13.5 ± 2.1 mm; p < 0.001), without further significant interval growth. SSP was not seen in patients < 3, but was 100% by ages 8-11. SSTs progressed from conchal/presellar (60% at ages 4-7) to sellar/postsellar (80% at adulthood).

CONCLUSION

The sella and parasellar regions have varied growth patterns with development. Knowledge of the expected maturation of key anterior skull base structures may augment surgical planning in younger patients.

Endoscopic Skull Base Surgery in the Pediatric Population

Background

Surgery is often indicated for definitive biopsy or as the primary treatment modality for pediatric skull base lesions. Traditionally, open surgical approaches were utilized to address pediatric skull base pathology. However recently, expanded endoscopic sinus surgery has been utilized as a minimally invasive approach to addressing skull base pathology in the pediatric population.

Purpose

This review provides an overview of the current literature evaluating the unique anatomic challenges of the pediatric skull and the safety and efficacy of expanded skull base procedures in the pediatric population.

Findings

The pediatric skull base and sinus anatomy is small and continues to develop throughout childhood leading to unique surgical challenges. Sphenoid sinus pneumatization and intercarotid distance at the skull base are two significant anatomic challenges to pediatric skull base surgery. Despite the distinctive anatomy challenges, recent studies demonstrate that the safety and efficacy of expanded endoscopic sinus surgery appear to be equivalent to traditional open surgical approaches.

Conclusion

Expanded endoscopic sinus surgery in the pediatric population has similar efficacy and safety as the traditional open approaches.

Applications of Endoscopic Endonasal Surgery in Early Childhood: A Case Series

INTRODUCTION

Endoscopic endonasal surgery (EES) has been slower to gain popularity in early childhood due to anatomical challenges. We sought to describe the safety and efficacy of EES in early childhood.

METHODS

All patients younger than 7 years who underwent EES at a large Cranial Base Center from 2002 to 2019 were reviewed as a retrospective cohort study.

RESULTS

Thirty-six patients underwent EES before the age of 7 years. Four patients had two-stage EES. Two patients required combined transcranial and endonasal approaches. The mean age at the time of initial surgery was 4 years (range: 1-6). Twenty patients were male, and 16 were female. Of 21 tumors intended for resection, 11 patients had gross total resections, and 10 had near total (>95% tumor removed) resections. Nine patients (43%) had recurrences, of which 6 were craniopharyngiomas (p = 0.01). There was no difference in recurrence rates based on the degree of resection (p = 0.67). Three cerebrospinal fluid (CSF) leaks occurred following primary EES (8%). Following an increase in nasoseptal flap usage (31-52%) and CSF diversion (15-39%) in 2008, there was only one CSF leak out of 23 patients (4 vs. 15%; p = 0.54). Postoperatively, 1 patient developed a permanent new cranial neuropathy, and 1 patient developed a permanent visual field cut. Six patients developed permanent postoperative panhypopituitarism, of which all were craniopharyngiomas (p < 0.001). The mean follow-up was 64 months.

CONCLUSIONS

Early childhood EES is both safe and technically feasible for a variety of pathologies.

First experience with augmented reality neuronavigation in endoscopic assisted midline skull base pathologies in children

INTRODUCTION

Endoscopic skull base approaches are broadly used in modern neurosurgery. The support of neuronavigation can help to effectively target the lesion avoiding complications. In children, endoscopic-assisted skull base surgery in combination with navigation systems becomes even more important because of the morphological variability and rare diseases affecting the sellar and parasellar regions. This paper aims to analyze our first experience on augmented reality navigation in endoscopic skull base surgery in a pediatric case series.

PATIENTS AND METHODS

A retrospective review identified seventeen endoscopic-assisted endonasal or transoral procedures performed in an interdisciplinary setting in a period between October 2011 and May 2020. In all the cases, the surgical target was a lesion in the sellar or parasellar region. Clinical conditions, MRI appearance, intraoperative conditions, postoperative MRI, possible complications, and outcomes were analyzed.

RESULTS

The mean age of our patients was 14.5 ± 2.4 years. The diagnosis varied, but craniopharyngiomas (31.2%) were mostly represented. AR navigation was experienced to be very helpful for effectively targeting the lesion and defining the intraoperative extension of the pathology. In 65% of the oncologic cases, a radical removal was proven in postoperative MRI. The mean follow-up was 89 ± 79 months. There were no deaths in our series. No long-term complications were registered; two cerebrospinal fluid (CSF) fistulas and a secondary abscess required further surgery.

CONCLUSION

The implementation of augmented reality to endoscopic-assisted neuronavigated procedures within the skull base was feasible and did provide relevant information directly in the endoscopic field of view and was experienced to be useful in the pediatric cases, where anatomical variability and rarity of the pathologies make surgery more challenging.

Endoscopic management of congenital nasal meningoencephaloceles: a short series of 15 paediatric cases

PURPOSE

To retrospectively analyse surgical management of clinico-radiologically proven nasal meningoencephalocele amongst children and results of repair with single-layer septo-mucosal flap at a tertiary skull base surgery centre in north India.

METHODS

Fifteen children with clinic-radiological nasal meningoencephaloceles with or without CSF rhinorrhoea were included. Radiological scans included CT scans and MRI scans for all cases to delineate soft tissue and bony architecture. All children underwent endoscopic excision of encephaloceles and repair of the skull base defect.

RESULTS

The authors were successful in fourteen cases. Successful cases included 4 children less than 6 months of age who underwent single-layer rotated septo-mucosal flaps, thereby avoiding donor site morbidity.

CONCLUSION

As endoscopic excision of nasal encephalocele is an established management approach, the authors take the concept of minimally invasive surgery a step further by successfully managing these lesions with single-layer repair. Vascularized septo-mucosal flap seems to be the only determining factor for a successful repair for congenital meningoencephalocele. However, a prospective study comprising a larger subset of patients would substantiate the assumption.

Sellar Remodeling after Surgery for Nonfunctioning Pituitary Adenoma: Intercarotid Distance as a Predictor of Recurrence

Introduction  As they grow, pituitary adenoma can remodel the sella turcica and alter anatomical relationships with adjacent structures. The intercarotid distance (ICD) at the level of the sella is a measure of sella width. The purpose of this study was to (1) assess how ICD changes after transsphenoidal surgery and (2) explore whether the extent of ICD change is associated with tumor recurrence. Methods  A retrospective analysis of preoperative and postoperative coronal magnetic resonance imaging (MRI) scans was carried out by two independent assessors on patients who underwent transsphenoidal surgery for nonfunctioning pituitary macroadenomas. Preoperative tumor volume and any change in ICD following surgery were recorded and compared between groups. Logistic regression models of recurrence were generated. Results  In 36 of 42 patients, ICD fell after surgery (mean = 1.8 mm) and six cases were static. At time of follow-up (mean = 77 months), 25 had not required further intervention and 17 had undergone second surgery or radiosurgery. In patients in whom no further intervention has yet been necessary, the postoperative reduction in ICD was significantly smaller than in those who required repeat intervention (1.1 vs. 2.7 mm respectively, p  < 0.01). ICD decrease was weakly correlated with tumor volume ( r  = 0.35). ICD decrease was a significant predictor of recurrence (odds ratio [OR] = 3.15; 95% confidence interval [CI]: 1.44-6.87), largely independent of tumor volume. Conclusion  For most patients, ICD falls following surgical excision of a nonfunctioning pituitary macroadenoma. A greater reduction in ICD postsurgery appears to predict recurrence. Change in ICD shows promise as a radiographic tool for prognosticating clinical course after surgery.

Outcomes of Endoscopic Versus Open Skull Base Surgery in Pediatric Patients

OBJECTIVE/HYPOTHESIS

To characterize the pathology and outcomes of skull base surgery in the pediatric population by open versus endoscopic surgical approach.

STUDY DESIGN

Retrospective cohort study.

METHODS

A retrospective review of pediatric patients (<18 years) who underwent skull base surgery for nonmalignant disease from May 2000 to August 2019 was performed. Patient demographics, pathology, and operative characteristics by surgical approach were recorded and analyzed. Patients with a combined endoscopic/open approach were classified as open for the analysis.

RESULTS

Eighty-two pediatric skull base patients were identified with a mean age of 11.3 years (standard deviation 5.2). A purely endoscopic approach was used in 63 (77%) patients, a purely open approach was used in nine (11%) patients, and a combined open/endoscopic approach was used in 10 (12%) patients. The all-cause complication rate was 9.8%. There was no statistically significant difference in rate of complications between patients with an open versus endoscopic approach for resection (15.8% vs. 7.9%; P = .379). Risk of having a complication did not significantly vary by patient age. The odds of having a complication with an open approach was not statistically significant in a multivariable model adjusted for age, sex, race, intraoperative cerebrospinal fluid leak, tracheostomy requirement, and vascular flap use (odds ratio 2.76, 95% confidence interval 0.28-26.94; P = .383).

CONCLUSIONS

Our retrospective study demonstrates a similar risk of complication for open versus endoscopic approach to resection in pediatric skull base patients at our institution. Safety and feasibility of the endoscopic approach has previously been demonstrated in children, and this is the first study to directly compare outcomes with open approaches.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:996-1001, 2021.

The expanded endonasal approach in pediatric skull base surgery: A review

OBJECTIVE

Surgery of the pediatric skull base has multiple unique challenges and has seen recent rapid advances. The objective of this review is to assess key issues in pediatric skull base surgery (SBS), including anatomic limitations, surgical approaches, reconstruction techniques, postoperative care, complications, and outcomes.

DATA SOURCES

PubMed literature review.

REVIEW METHODS

A review of the literature was conducted to assess the challenges, recent advances, and reported outcomes in pediatric SBS.

RESULTS

The pediatric skull base presents multiple anatomic challenges, including variable patterns of pneumatization, narrow piriform aperture width, and narrow intercarotid distance at the level of the cavernous sinus but not the superior clivus. These issues may be particularly challenging in patients less than 2 years of age. Endoscopic endonasal approaches in the sagittal and coronal plane have been applied to the pediatric skull base while open approaches may still be necessary in the setting of extensive intracranial or orbital disease, as well as disease lateral to critical neurovascular structures. While the nasoseptal flap was initially called into question for pediatric cases, it has been shown through multiple reports to be a feasible and robust reconstructive option. Complications and outcomes often depend upon the pathology. In children, response to noxious stimuli, ability to avoid Valsalva, and adherence to nasal precautions is variable. The use of lumbar drains is more common in pediatric than adult patients.

CONCLUSION

While the pediatric skull base presents unique challenges, outcomes data support that endoscopic endonasal approaches are a pertinent surgical technique in appropriately selected patients.

LEVEL OF EVIDENCE

3a.

The limits of endoscopic endonasal approaches in young children: a review

INTRODUCTION

The endoscopic endonasal approach (EEA) provides visualization of four deep surgical corridors (transcribiform, transtubercular, transsellar, and transclival) with superior illumination and specialized deep-reaching instruments, as compared to microscopic techniques. Several studies have evaluated EEAs in children but do not stratify for the very young of age, whose particularly small nares and developmental anatomy may limit endonasal instrumentation.

METHODOLOGY

A comprehensive review of EEAs in infants and children to age 4 was performed to determine the limitations in this age group.

RESULTS

Eighteen studies were identified describing this approach for pediatric patients and the surgical caveats and limitations were reviewed. In very small children, CSF leaks, meningioencephaloceles, tumors of the anterior skull base, and lesions at the rostral cervical spine have been successfully treated endonasally. While newer studies advocate using 2.7-mm diameter (18-cm length) lenses, 4-mm diameter rigid lenses have been used without technical difficulty. The youngest patient in whom an EEA was used was a 6-week-old for a dermoid resection. Some have advocated that due to the small nares, approaches via bilateral entry are optimal for multiple instruments, however, others, including authors of a series of 28 repaired CSF leaks demonstrate successful single nare access.

DISCUSSION

EEAs are associated with less blood loss, are less likely to hinder normal growth of the skull and midface, and allow for the resection of even malignant lesions. Despite the limitations of the frontal, ethmoid, and sphenoid sinuses before age 3, reports have not documented insurmountable difficulty with EEAs even in infants. 2.7-mm diameter endoscopes are favored unilaterally or bilaterally to treat both benign and malignant lesions and preserve the young patient's facial anatomy better than older methods. Ever improving technology has facilitated the use of this approach in patients it would otherwise be infeasible for in the past, but it still cannot overcome the anatomical constraints of certain young patients in which this approach remains unindicated. Patient selection is therefore of utmost importance and the risks and benefits of more extensive approaches in these cases must be considered.

The Change in Distance Between Bilateral Internal Carotid Arteries in Acromegaly and Its Risk Factors

Background: Studies investigating the change in distance between the bilateral internal carotid arteries (ICAs) in acromegalic patients have provided ambiguous results. The influencing factors of these changes have not been well-identified. Objective: To further investigate the change in distance between bilateral ICAs in acromegaly patients and identify the influencing factors of the change. Method: Patients diagnosed as acromegaly from Jan 2016 to Sep 2019 in the Department of Neurosurgery of the First Affiliated Hospital of Fujian Medical University, were included in this study. Computed tomography angiography (CTA) or magnetic resonance angiography (MRA) data were obtained for all patients for three-dimensional reconstruction of the ICAs. Distance between bilateral ICAs was measured and recorded for assessment. Result: 172 patients including 86 cases with acromegaly in the study group and 86 cases with non-functional pituitary adenoma in the control group were enrolled in this study. The difference of adenoma sizes between two groups was not statistically significant. Patients in acromegaly group had significantly larger maximum distances between bilateral siphon carotid ectasias (25.5 ± 4.1 vs. 23.4 ± 3.5 mm, P = 0.001) and between bilateral lacerum segments (26.2 ± 3.2 vs. 24.1 ± 4.3 mm, P < 0.001) compared with those of patients with non-functional pituitary adenomas. Multivariate analysis showed that the increased bilateral ICAs distance was associated with disease duration (odds ratio = 1.01, 95% confidence interval = 1.01-1.02, P = 0.005) and refractory pituitary adenoma (odds ratio = 9.8, 95% confidence interval = 1.1-88.7, P = 0.043) but not with level of growth hormone (GH), insulin-like growth factor-1 (IGF-1) and adenoma size in acromegaly. Conclusion: Our study showed significant change in distance between the bilateral ICAs in acromegalic patients, comparing to patients with non-functional pituitary adenomas. The increased intercarotid artery distance is associated with disease duration but not with preoperative level of GH and IGF-1. Refractory pituitary adenoma and longer disease duration are the both risk factors of the increased ICAs distance in patient with acromegly.

The endoscopic endonasal approach for pediatric craniopharyngiomas: the key lessons learned

PURPOSE

The aim of this study is to highlight the role of the endoscopic endonasal approach (EEA) in pediatric craniopharyngiomas by reviewing our experience and the key lessons learned from the application of this approach in children.

METHODS

Between 1998 and 2017, 12 pediatric craniopharyngiomas were treated via EEA at our institution. Demographic data, preoperative assessment, tumor features, surgical results, complications, and recurrences were analyzed.

RESULTS

Visual defects were the most frequent presenting sign. Seven craniopharyngiomas were infradiaphragmatic, and five were supradiaphragmatic. The EEA was successfully performed in all cases with no complication related to children's sinonasal anatomy. Gross total resection (GTR) rate was of 75%. Endocrinological disturbances improved in one case (20%) and worsened in three (60%). New onset of diabetes insipidus was observed in four (36%) children. Visual defect improved in 91% of cases, with no new postoperative deficit. Postoperative cerebrospinal fluid (CSF) leak occurred in one patient (8%). Three patients (27%) experienced tumor regrowth, and one craniopharyngioma recurred (mean follow-up, 78 months).

CONCLUSIONS

The EEA offers a straight route to the sellar-suprasellar, making it the ideal approach for pediatric infradiaphragmatic craniopharyngiomas. In supradiaphragmatic craniopharyngiomas, the extended EEA provides a clearer and close-up visualization of the tumor-hypothalamus interface, which can grant better results in terms of quality of life. The pediatric skull base anatomy should not represent a contraindication for the endoscopic technique. Larger series encompassing a wider spectrum of pediatric craniopharyngiomas are needed to further support the benefits of this surgical approach.

Endoscopic endonasal skull base surgery for pediatric brain tumors

PURPOSE

The utility of endoscopic endonasal skull base surgery (EES) in various pathologic entities in adults has been published in the literature. However, the role of EES in children has not been clearly elucidated. We evaluated the feasibility of EES in children with brain tumors.

METHODS

We retrospectively reviewed clinical features, surgical outcomes, and complications in children who underwent EES for intracranial and skull base tumors at a single institution from July 2010 to October 2018.

RESULTS

A total of 82 patients underwent EESs for 77 intracranial and 5 skull base bony tumors. The mean age at diagnosis was 11.4 years (range 4-18 years), and the mean follow-up period was 46.8 months. The most common tumors were craniopharyngioma in the intracranial tumor and chordoma in the skull base. Gross total resection was the goal of surgery in 55 patients and achieved in 90.9%. The vision was improved in 76.1% of patients with visual impairments. Preoperatively, various endocrinological deficiencies were revealed in 73.7% of 76 patients with hypothalamus-pituitary lesions, and the hyposomatotropism was most common. Endocrinological status was improved only in 10. Aseptic or bacterial meningitis (7.3%) was the most common surgical complication, and the cerebrospinal fluid leakage rate was 2.4%.

CONCLUSIONS

EES provides favorable neurological outcomes with acceptable risk for children with brain tumors. The high incidence of endocrinological deficits in cases with hypothalamus-pituitary lesions emphasizes the importance of judicious pre- and postoperative evaluation.

Peel-Away Catheter Introducer Sheath for Reducing Nasal Traumatic Injury During Pediatric Endoscopic Skull Base Surgery

OBJECTIVE

Pediatric endoscopic endonasal surgery represents a still-growing discipline to approach complex skull base lesions and is characterized by unfavorable anatomical conditions. Children have very small nostrils and narrow rhinosinusal corridors, which could lead more easily to accidental injury to the nasal structures. We describe the use of a peel-away catheter introducer sheath as an innovative and minimally invasive technique to further reduce surgical trauma to the nasal mucosa and structures in pediatric rhinoneurosurgery.

METHODS

From January 2009 to December 2018, the peel-away sheath technique was used in 6 pediatric endoscopic procedures for biopsy and/or removal of skull base tumors.

RESULTS

The endoscopic technique with the use of the peel-away catheter allowed clear visualization of the surgical field during the whole course of the procedure and good surgical maneuverability. The use of the peel-away sheath did not prolong the surgical operation time and provided a good working channel. No intraoperative or postoperative major complications were observed. No nasal short-term complications were registered in all patients.

CONCLUSIONS

The use of a peel-away catheter introducer sheath technique represents a valid adjunct in the endoscopic pediatric skull base surgery repertoire. It can help in avoiding inadvertent surgical traumas to the sinonasal structures, especially by residents and junior surgeons. This could potentially reduce postoperative nasal morbidity.

Lack of Sphenoid Pneumatization Does Not Affect Endoscopic Endonasal Pediatric Skull Base Surgery Outcomes

OBJECTIVES/HYPOTHESIS

Currently, due to the rarity of pathology, there are limited data surrounding outcomes of pediatric skull base surgery. Traditionally, surgeons have proceeded with caution when electing endonasal endoscopic transsellar/transplanum approaches to the skull base in pediatric patients due to poor sphenoid pneumatization. In this study, we review outcomes of endoscopic pediatric skull base surgery based on sphenoid pneumatization patterns.

STUDY DESIGN

Retrospective chart review.

METHODS

A review of all cases of pediatric (age < 18 years) craniopharyngioma managed via an endoscopic endonasal approach at a tertiary academic medical center.

RESULTS

A total of 27 patients were included in the analysis. The median age was 8 years. Nineteen (70%) patients were male. Presellar, sellar/postsellar, and conchal sphenoid pneumatizations were found in 6, 11, and 10 patients, respectively. There was no significant association between sphenoid pneumatization pattern and extent of resection (gross vs. subtotal, P = .414), postoperative cerebrospinal fluid (CSF) leak (P = .450), intraoperative estimated blood loss (P = .098), total operative time (P = .540), and length of stay (P = .336). On multivariate analysis, after accounting for age, sex, preoperative cranial nerve involvement, and cavernous sinus invasion, there remained no significant association between sphenoid pneumatization pattern and extent of resection (P = .999) and postoperative CSF leak (P = .959).

CONCLUSIONS

Sphenoid pneumatization pattern does not appear to affect outcomes in endoscopic skull base surgery in the pediatric population. Importantly, lack of sphenoid pneumatization does not impede gross total resection or increase complications. Thorough knowledge of the anatomy during the endoscopic approach is critical to optimize outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:832-836, 2019.

Developmental Considerations in Pediatric Skull Base Surgery

Objectives  To review developmental surgical anatomy and technical nuances related to pediatric skull base surgery. Design  Retrospective, single-center case series with literature review. Setting  MD Anderson Cancer Center. Participants  Patients undergoing pediatric skull base surgery. Main Outcome Measures  Review developmental anatomy of the pediatric skull base as it relates to technical nuance of various surgical approaches and insight gained from a 25-year institutional experience with this unique patient population. Results  Thirty-nine patients meeting these criteria were identified over a 13-year period from 2003 to 2016 and compared to a previously reported earlier cohort from 1992 to 2002. The most common benign pathologies included nerve sheath tumors (11%), juvenile nasopharyngeal angiofibromas (9.5%), and craniopharyngiomas (4.8%). The most common malignancies were chondrosarcoma (11%), chordoma (11%), and rabdomyosarcoma (11%). Varied surgical approaches were utilized and were similar between the two cohorts save for the increased use of endoscopic surgical techniques in the most recent cohort. The most common sites of tumor origin were the infratemporal fossa, sinonasal cavities, clivus, temporal bone, and parasellar region. Gross total resection and postoperative complication rates were similar between the two patient cohorts. Conclusions  Pediatric skull base tumors, while rare, often are treated surgically, necessitating an in depth understanding of the anatomy of the developing skull base.

Endoscopic Management of Developmental Anomalies of the Skull Base

Developmental anomalies of the skull base may present in childhood or as an adult. The most common pathologies include dermoid, encephalocele, and glioma. Encephaloceles may present as part of a syndrome. Other entities include infantile hemangiomas and teratoma. Endoscopic techniques provide a less invasive and morbid option for treatment. Proper evaluation and treatment is necessary to prevent complications such as meningitis.

Fibro-Osseous Lesions of the Skull Base in the Pediatric Population

Fibro-osseous lesions of the skull base include a variety of lesions with different biologic behavior. The most common lesions include fibrous dysplasia, osteoma, aneurysmal bone cyst, and juvenile ossifying fibroma. The diagnosis can usually be established with radiographic imaging. In the absence of symptoms, slow-growing lesions can often be observed. When surgery is indicated for relief of symptoms, endoscopic endonasal techniques are well suited for all age groups.

Suprasellar and recurrent pediatric craniopharyngiomas: expanding indications for the extended endoscopic transsphenoidal approach

OBJECTIVE The expanded endonasal endoscopic transsphenoidal approach has become increasingly used for craniopharyngioma surgery in the pediatric population, but questions still persist regarding its utility in younger children, in recurrent and irradiated tumors, and in masses primarily located in the suprasellar region. The narrow corridor, incomplete pneumatization, and fear of hypothalamic injury have traditionally relegated this approach to application in older children with mostly cystic craniopharyngiomas centered in the sella. The authors present a series of consecutive pediatric patients in whom the endonasal endoscopic approach was used to remove craniopharyngiomas from patients of varied ages, regardless of the location of the tumor and previous treatments or surgeries, to ascertain if the traditional concerns about limitations of this approach are worth reevaluating METHODS Eleven consecutive pediatric patients (age ≤ 18 years) underwent surgery via an endoscopic transsphenoidal approach at NewYork-Presbyterian/Weill Cornell Medical Center from 2007 to 2016. The authors recorded the location, consistency, and size of the lesion, assessed for hypothalamic invasion radiographically, calculated skull base measurements, and assessed parameters such as extent of resection, visual function, endocrinological function, weight gain, and return-to-school status. RESULTS The average age at the time of surgery was 7.9 years (range 4-17 years) and the tumor sizes ranged from 1.3 to 41.7 cm³. Five cases were purely suprasellar, 5 had solid components, 4 were reoperations, and 5 had a conchal sphenoid aeration. Nevertheless, gross-total resection was achieved in 45% of the patients and 50% of those in whom it was the goal of surgery, without any correlation with the location, tumor consistency, or the age of the patient. Near-total resection, subtotal resection, or biopsy was performed intentionally in the remaining patients to avoid hypothalamic injury. Anterior pituitary dysfunction occurred in 81.8% of the patients, and 63.3% developed diabetes insipidus . Two patients (18%) had a greater than 9% increase in body mass index. Visual function was stable or improved in 73%. All children returned to an academic environment, with 10 of them in the grade appropriate for their age. There was a single case of each of the following: CSF leak, loss of vision unilaterally, and abscess. CONCLUSIONS The endoscopic transsphenoidal approach is suitable for removing pediatric craniopharyngiomas even in young children with suprasellar tumors, conchal sphenoid sinus, recurrent tumors, and tumors with solid components. The extent of resection is dictated by intrinsic hypothalamic tumor invasiveness rather than the approach. The endoscopic transsphenoidal approach affords the ability to directly inspect the hypothalamus to determine invasion, which may help spare the patient from hypothalamic injury. Irrespective of approach, the rates of postoperative endocrinopathy remain high and the learning curve for the approach to a relatively rare tumor is steep.

Is the chiasm-pituitary corridor size important for achieving gross-total resection during endonasal endoscopic resection of craniopharyngiomas?

OBJECTIVE Craniopharyngiomas arise from the pituitary stalk, and in adults they are generally located posterior to the chiasm extending up into the third ventricle. The extended endonasal approach (EEA) can provide an ideal corridor between the bottom of the optic chiasm and the top of the pituitary gland (chiasm-pituitary corridor [CPC]) for their removal. A narrow CPC in patients with a prefixed chiasm and a large tumor extending up and behind the chiasm has been considered a contraindication to EEA, with a high risk of visual deterioration and subtotal resection. METHODS A database of all patients treated in the authors' center (Weill Cornell Medical College, NewYork-Presbyterian Hospital) between July 2004 and August 2016 was reviewed. Patients with craniopharyngiomas who underwent EEA with the goal of gross-total resection (GTR) were included in the study. Patients with postfixed chiasm or limited available preoperative imaging were excluded. Using preoperative contrast-enhanced T1-weighted sagittal midline MR images, the authors calculated the CPC as well as the distance from the chiasm to the top of the tumor (CTOT). From these numbers, they calculated a ratio of the CPC to the CTOT as a measure of difficulty in removing the tumors through the EEA and called this ratio the corridor index (CI). The relationship between the CI and the ability to achieve GTR and visual outcome were measured. RESULTS Thirty-four patients were included in the study. The mean CPC was 10.1 mm (range 5.2-19.1 mm). The mean CTOT was 12.8 mm (range 0-28.3 mm). The median CI was 0.8; the CI ranged from 0.4 to infinity (for tumors with a CTOT of 0). Thirty-two patients had GTR (94.1%) and 2 had subtotal resection. The CPC value had no relationship with our ability to achieve GTR and no effect on visual or endocrine outcome. CONCLUSIONS EEA for craniopharyngioma is generally considered the first-line surgical approach. Although a narrow corridor between the top of the pituitary gland and the bottom of the chiasm may seem to be a relative contraindication to surgery for larger tumors, the authors' data do not bear this out. EEA appears to be a successful technique for the majority of midline craniopharyngiomas.

Transorbital endoscopic approach for exposure of the sylvian fissure, middle cerebral artery and crural cistern: an anatomical study

BACKGROUND

The availability of minimal access instrumentation and endoscopic visualization has revolutionized the field of minimally invasive skull base surgery. The transorbital endoscopic approach using an eyelid incision has been proposed as a new minimally invasive technique for the treatment of skull base pathology, mostly extradural tumors. Our study aims to evaluate the anatomical aspects and potential role of the transorbital endoscopic approach for exposure of the sylvian fissure, middle cerebral artery and crural cistern.

METHODS

An anatomical dissection was performed in four freshly injected cadaver heads (8 orbits) using 0- and 30-degree endoscopes. First, an endoscopic endonasal medial orbital decompression was done to facilitate medial retraction of the orbit. An endoscopic transorbital approach through an eyelid incision, with drilling of the posterior wall of the orbit and lesser sphenoidal wing, was then performed to expose the sylvian fissure and crural cisterns. A stepwise anatomical description of the approach and visualized anatomy is detailed.

RESULTS

A superior eyelid incision followed by orbital retraction provided a surgical window of approximately 1.2 cm (range 1.0-1.5 cm) for endoscopic transorbital dissection. The superior (SOF) and inferior (IOF) orbital fissures represent the medial limits of the approach and are identified in the initial part of the procedure. Drilling of the orbital roof (lateral and superior to the SOF), greater sphenoidal wing (lateral to the SOF and IOF) and lesser sphenoidal wing exposed the anterior and middle fossa dura. A square-shaped dural opening provided visualization of the posterior orbital gyri, sylvian fissure and temporal pole. Intradural dissection allowed exposure of the sphenoidal portion of the sylvian fissure, M1, MCA bifurcation and M2 branches and lenticulostriate perforators. Dissection of the medial aspect of the sylvian and carotid cisterns with a 30-degree endoscope allowed exposure of the mesial temporal lobe and crural cistern.

CONCLUSIONS

The transorbital endoscopic approach allows successful exposure of the sphenoidal portion of the sylvian fissure and M1 and M2 segments of the middle cerebral artery. Angled endoscopes may provide visualization of the mesial temporal lobe and crural cistern. Although our anatomical study demonstrates the feasibility of intradural dissection and closure via an endoscopic transorbital approach, further studies are necessary to evaluate its role in the clinical scenario.

Cerebral Vein Malformations Result from Loss of Twist1 Expression and BMP Signaling from Skull Progenitor Cells and Dura

Dural cerebral veins (CV) are required for cerebrospinal fluid reabsorption and brain homeostasis, but mechanisms that regulate their growth and remodeling are unknown. We report molecular and cellular processes that regulate dural CV development in mammals and describe venous malformations in humans with craniosynostosis and TWIST1 mutations that are recapitulated in mouse models. Surprisingly, Twist1 is dispensable in endothelial cells but required for specification of osteoprogenitor cells that differentiate into preosteoblasts that produce bone morphogenetic proteins (BMPs). Inactivation of Bmp2 and Bmp4 in preosteoblasts and periosteal dura causes skull and CV malformations, similar to humans harboring TWIST1 mutations. Notably, arterial development appears normal, suggesting that morphogens from the skull and dura establish optimal venous networks independent from arterial influences. Collectively, our work establishes a paradigm whereby CV malformations result from primary or secondary loss of paracrine BMP signaling from preosteoblasts and dura, highlighting unique cellular interactions that influence tissue-specific angiogenesis in mammals.

Intraoperative magnetic resonance imaging in pediatric neurosurgery: safety and utility

OBJECTIVE The use of high-field intraoperative MRI has been largely studied for the treatment of intracranial tumors in adult patients. In this study, the authors investigated the safety, advantages, and limitations of high-field iMRI for cranial neurosurgical procedures in pediatric patients, with particular attention to craniopharyngiomas and gliomas. METHODS The authors performed 82 surgical procedures in patients under 16 years of age (range 0.8-15 years) over an 8-year period (2007-2014) using iMRI. The population was divided into 3 groups based on the condition treated: sellar region tumors (Group 1), gliomas (Group 2), and other pathological entities (Group 3). The patients' pre- and postoperative neurological status, the presence of residual tumor, the number of intraoperative scans, and complications were evaluated. RESULTS In Group 1, gross-total resection (GTR) was performed in 22 (88%) of the procedures and subtotal resection (STR) in 3 (12%). In Group 2, GTR, STR, and partial resection (PR) were performed, respectively, in 15 (56%), 7 (26%), and 5 (18%) of the procedures. In Group 3, GTR was performed in 28 (93%) and STR in 2 (7%) of the procedures. In cases of craniopharyngioma (Group 1) and glioma (Group 2) in which a complete removal was planned, iMRI allowed localization of residual lesions and attainment of the surgical goal through further resection, respectively, in 18% and 27% of the procedures. Moreover, in gliomas the resection could be extended from partial to subtotal in 50% of the cases. In 17% of the patients in Group 3, iMRI enabled the identification and further removal of tumor remnants. There was no intra- or postoperative complication related to the use of iMRI despite special technical difficulties in smaller children. CONCLUSIONS In this study, the use of iMRI in children proved to be safe. It was most effective in increasing the extent of tumor resection, especially in patients with low-grade gliomas and craniopharyngiomas. The most prominent disadvantage of high-field iMRI was the limitation with respect to operative positioning due to the configuration of the surgical table.

Predicting the limits of the endoscopic endonasal approach in children: a radiological anatomical study

OBJECT The endoscopic endonasal approach (EEA) has been established as an alternative approach to craniovertebral junction (CVJ) pathology in adults. The authors have previously described the nasoaxial line (NAxL) as an accurate predictor of the lower limit of the EEA to the CVJ in adults. The surgical anatomy limiting the EEA to the pediatric CVJ has not been well studied. Furthermore, predicting the lower limit of the EEA in various pediatric age groups is important in surgical planning. To better understand the anatomy affecting the EEA to the CVJ, the authors examined the skull base anatomy relevant to the EEA in children of different age groups and used the NAxL to predict the EEA lower limit in children. METHODS Axial brain CT scans of 39 children with normal skull base anatomy were reconstructed sagittally. Children were divided into 4 groups according to age: 3-6, 7-10, 11-14, and 15-18 years old. The intersection of the NAxL with the odontoid process of C-2 was described for each group. Analyses of variance were used to estimate the effect of age, sex, interaction between age and sex on different anatomical parameters relevant to the endonasal corridor (including the length of the hard palate [HPLe]), dimensions of choana and piriform aperture, and the length of the NAxL to C-2. The effect of the HPLe on the working distance of NAxL to the odontoid was also estimated using analysis of covariance, controlling for age, sex, and their interaction. RESULTS The NAxL extended to the odontoid process in 38 of the 39 children. Among the 39 children, the NAxL intersected the upper third of the odontoid process in 25 while intersecting the middle third in the remaining 13 children. The measurements of the inferior limits did not differ with age, varying between 9 and 11 mm below the hard palate line at the ventral surface of C-2. Significant increases in the size of the piriform aperture and choana and the HPLe were observed after age 10. The HPLe predicted the length of the NAxL (p < 0.0001). CONCLUSIONS The caudal limit of the EEA extends as far as the middle third of the odontoid process in children, as predicted by the NAxL. The most prominent increase in the size of the choana and piriform aperture occurs after age 10. The HPLe is a significant predictor of the working distance to C-2. Utilizing the NAxL preoperatively may help in planning the EEA to the CVJ in children.

The rise and fall of the craniocervical junction relative to the hard palate: a lifetime story

OBJECT

Endoscopic approaches to the anterior craniocervical junction are increasing in frequency. Choice of oral versus endoscopic endonasal approach to the odontoid often depends on the relationship of the C1–2 complex to the hard palate. However, it is not known how this relevant anatomy changes with age. We hypothesize that there is a dynamic relationship of C-2 and the hard palate, which changes with age, and potentially affects the choice of surgical approach. The aim of this study was to characterize the relationship of C-2 relative to the hard palate with respect to age and sex.

METHODS

Emergency department billing and trauma records from 2008 to 2014 were reviewed for patients of all ages who underwent cervical or maxillofacial CT as part of a trauma evaluation for closed head injury. Patients who had a CT scan that allowed adequate visualization of the hard palate, opisthion, and upper cervical spine (C-1 and C-2) were included. Patients who had cervical or displaced facial/skull base fractures, a history of rheumatoid arthritis, or craniofacial anomalies were excluded. The distance from McGregor's palatooccipital line to the midpoint of the inferior endplate of C-2 (McL–C2) was measured on midsagittal CT scans. Patients were grouped by decile of age and by sex. A 1-way ANOVA was performed with each respective grouping.

RESULTS

Ultimately, 483 patients (29% female) were included. The mean age was 46 ± 24 years. The majority of patients studied were in the 2nd through 8th decades of life (85%). Significant variation was found between McL–C2 and decile of age (p < 0.001) and sex (p < 0.001). The mean McL–C2 was 27 mm in the 1st decade of life compared with the population mean of 37 mm. The mean McL–C2 was also noted to be smaller in females (mean difference 4.8 mm, p < 0.0001). Both decile of age (p = 0.0009) and sex (p < 0.0001) were independently correlated with McL–C2 on multivariate analysis.

CONCLUSIONS

The relationship of C-2 and the hard palate significantly varies with respect to age and sex, descending relative to the hard palate a full centimeter on average in adulthood. These findings may have relevance in determining optimal surgical approaches for addressing pathology involving the anterior craniocervical junction.

Endoscopic endonasal surgery for benign fibro-osseous lesions of the pediatric skull base

OBJECTIVES/HYPOTHESIS

To describe the presentation, treatment, and outcomes of benign fibro-osseous tumors involving the skull base in a pediatric population.

METHODS

Retrospective chart review from January 2002 to September 2013 of pediatric patients (ages 0-18 years) who underwent endoscopic endonasal surgery (EES) for benign fibro-osseous tumors involving the skull base.

RESULTS

Fourteen patients were identified with an age range of 2.7 to 17.9 years (mean, 12.5 years). Six juvenile ossifying fibromas, five benign fibro-osseous lesions, two osteomas, and one fibrous dysplasia were treated. Ocular symptoms and nasal obstruction were the most common presenting symptoms in nine (64%) and six (43%) of patients, respectively; five (36%) presented with proptosis and four (29%) with diplopia. Two (14%) patients had cranial nerve VI palsy. Transsellar and transclival approaches were used in five (36%) of patients. Orbital and optic nerve decompressions were the most common components of the approaches performed in nine (64%) of the surgeries. Gross total resection (GTR) was achieved with single-stage surgery in 10 (71%) patients; two additional patients underwent staged GTR. Two intraoperative cerebrospinal fluid (CSF) leaks occurred and were repaired endoscopically. There were no postoperative CSF leaks or infectious complications. Two patients had transient diplopia, and two had transient diabetes insipidus, all of which resolved. The mean follow-up was 13.8 months. Two patients had a recurrence, and both required additional EES achieving GTR.

CONCLUSIONS

EES for benign fibro-osseous tumors of the skull base is a safe and effective treatment for excision of these lesions in the pediatric population.

LEVEL OF EVIDENCE

4.

Endoscopic extended transsphenoidal resection of craniopharyngiomas: nuances of neurosurgical technique

Endoscopic approaches to the midline ventral skull base have been extensively developed and refined for resection of cranial base tumors over the past several years. As these techniques have improved, both the degree of resection and complication rates have proven comparable to those for transcranial approaches, while visual outcomes may be better via endoscopic endonasal surgery and hospital stays and recovery times are often shorter. Yet for all of the progress made, the steep learning curve associated with these techniques has hampered more widespread implementation and adoption. The authors address this obstacle by coupling a thorough description of the technical nuances for endoscopic endonasal craniopharyngioma resection with detailed illustrations of the important steps in the operation. Traditionally, transsphendoidal approaches to craniopharyngiomas have been restricted to lesions mostly confined to the sella. However, recently, endoscopic endonasal resections are more frequently employed for extrasellar and purely third ventricle craniopharyngiomas, whose typical retrochiasmatic location makes them ideal candidates for endoscopic transnasal surgery. The endonasal endoscopic approach offers many advantages, including direct access to the long axis of the tumor, early tumor debulking with minimal manipulation of the optic apparatus, more precise visualization of tumor planes, particularly along the undersurface of the chiasm and the roof of the third ventricle, and a minimal-access corridor that obviates the need for brain retraction. Although much emphasis has been placed on technical tenets of exposure and "how to get there," this article focuses on nuances of tumor resection "when you are there." Three operative videos illustrate our discussion of technical tenets.

Anterior skull-base surgery: current opinion

PURPOSE OF REVIEW

The field of anterior skull-base surgery has undergone rapid advancement in the last 10-15 years. As a result, tumors of the anterior skull base that were once considered inoperable are now routinely resected with reliable results and decreasing morbidity. The purpose of this review is to highlight the most up-to-date opinions and advancements within the field, and to evaluate the recent advances in the surgical management of anterior skull-base tumors.

RECENT FINDINGS

In the last year, the body of literature in anterior skull-base surgery has been expanded with new anatomic insights, surgical techniques, and data on patient outcomes and quality of life. Much of this literature is focused on minimally invasive, endoscopic techniques, which have expanded greatly in the last decade.

SUMMARY

This article summarizes the most current opinion in the field of anterior skull-base surgery. Recent literature regarding new anatomic insights, surgical techniques (resection and reconstruction), and outcomes data are outlined.

Nasoseptal flap reconstruction of pediatric sellar defects: a radiographic feasibility study and case series

OBJECTIVES

In this study, we used computed tomography measurements to investigate the feasibility of nasoseptal flap reconstruction of sellar defects in children, and we reviewed our institutional experience with the procedure.

STUDY DESIGN

Cross-sectional and case series.

SETTING

Pediatric tertiary care facility.

METHODS

We obtained 10 normal maxillofacial scans for each year of age from birth to 18. Computer-assisted nasal and skull-base measurements were performed. Patients with incomplete pneumatization were excluded from analysis. Reconstruction was presumed feasible if the ratio of nasoseptal flap length to associated sellar defect length was greater than 1. Chart review identified surgical patients.

RESULTS

Of 190 scans, 125 had complete pneumatization. Of these, 120 (96%) displayed a ratio of nasoseptal flap length to sellar defect length greater than 1, suggesting that reconstruction would be feasible. Mean ratio of flap length to defect length for all subjects was 1.47 (SD 0.33; 95% CI, 1.41-1.53). Only 5 of 125 patients (4%) had a ratio less than 1; the median age for these patients was 15 years, which is older than the median age of 12 years for subjects with a ratio greater than 1 (P = .02). An inverse relationship was identified between age and ratio of flap length to defect length (r = -0.49, P < .001). Case series identified 6 children, ages 5 to 17; flap length was never described as a limitation.

CONCLUSIONS

Nasoseptal flap length is not a limiting factor for reconstruction of pediatric sellar defects. When compared with older patients, younger patients tend to have greater nasoseptal flap length relative to sellar defect length.

Endoscopic Endonasal Repair of Congenital Defects of the Anterior Skull Base: Developmental Considerations and Surgical Outcomes

Techniques of endoscopic endonasal surgery, initially developed primarily for intracranial neoplasms, have been adapted to treat a wide variety of pathologies previously addressed with open craniotomy including congenital and acquired defects of the anterior skull base. Congenital defects can lead to herniation of leptomeninges containing cerebrospinal fluid alone or with brain tissue. Specific types of encephalocele can be defined on the basis of the associated abnormal bony anatomy. Endoscopic endonasal surgery represents a relatively recent development in the treatment of these entities. Technical considerations include relatively younger age range of the patient population, dimensions of preexisting bony defect, volume of herniated meninges and brain tissue, and distorted anatomy from abnormal development of the affected craniofacial skeleton. Recent highly detailed anatomical studies have quantitatively verified the utility of endoscopic endonasal surgery in the pediatric population. Particular attention has been directed toward adequacy of nasoseptal flap reconstruction in pediatric patients. Several reports have described patients with encephalocele of the anterior cranial fossa successfully treated with endoscopic surgery. The literature on endoscopic repair of congenital encephalocele is reviewed. Outcomes have generally been reported as favorable, although long-term follow-up and systematic studies have not been pursued.

The costs of skull base surgery in the pediatric population

Objectives To determine the costs of endoscopic endonasal surgery (EES) for pediatric skull base lesions. Methods Retrospective chart review of pediatric patients (ages 1 month to 19 years) treated for skull base lesions with EES from 1999 to 2013. Demographic and operative data were recorded. The cost of care for the surgical day, intensive care unit (ICU), floor, and total overall cost of inpatient stay were acquired from the finance department. Results A total of 160 pediatric patients undergoing EES for skull base lesions were identified. Of these, 55 patients had complete financial data available. The average total inpatient and surgical costs of care were $34, 056 per patient. Angiofibromas were the most costly: $59,051 per patient. Fibro-osseous lesions had the lowest costs: $10,931 per patient. The average ICU stay was 1.8 days at $4,577 per ICU day. The average acute care stay was 3.4 days at $1,961 per day. Overall length of stay was 4.5 days. Three cerebrospinal fluid leaks (4%) and two cases of meningitis (3%) occurred. One tracheostomy was required (1.5%). Conclusions EES is a cost-effective model for removal of skull base lesions in the pediatric population. Costs of care vary according to pathology, staged surgeries, length of ICU stay, and need for second operations.