Approaching the Sella through the Nonpneumatized Sphenoid in Pediatric Patients

Surgical management of Rathke cleft cysts in pediatric patients: a single institution experience

OBJECTIVE

Rathke cleft cysts (RCCs) are benign, epithelial-lined sellar lesions that arise from remnants of the craniopharyngeal duct. Due to their rarity in the pediatric population, data are limited regarding the natural history and optimal management of growing or symptomatic RCCs. We present our institutional experience with the surgical management of RCCs.

METHODS

We performed a retrospective study of consecutive RCC patients ≤ 18 years old treated surgically at our institution between 2006 and 2022.

RESULTS

Overall, 567 patients with a diagnosis of pituitary mass or cyst were identified. Of these, 31 had a histopathological diagnosis of RCC, 58% female and 42% male. The mean age was 13.2 ± 4.2 years. Presenting symptoms included headache (58%), visual changes (32%), and endocrinopathies or growth delay (26%); 13% were identified incidentally and subsequently demonstrated growth on serial imaging. Six percent presented with symptomatic intralesional hemorrhage. Surgical approach was transsphenoidal for 90% of patients and orbitozygomatic for 10%. Preoperative headaches resolved in 61% of patients and preoperative visual deficits improvement in 55% after surgery. New pituitary axis deficits were seen in 9.7% of patients. Only two complications occurred from a first-time surgery: one cerebrospinal fluid leak requiring lumbar drain placement, and one case of epistaxis requiring cauterization. No patients experienced new visual or neurological deficits. Patients were followed postoperatively with serial imaging at a mean follow-up was 62.9 ± 58.4 months. Recurrence requiring reoperation occurred in 32% of patients. Five-year progression-free survival was 47.9%. Except for one patient with multiple neurological deficits from a concurrent tectal glioma, all patients had a modified Rankin Scale score of 0 or 1 (good outcome) at last follow-up.

CONCLUSION

Due to their secretory epithelium, pediatric RCCs may demonstrate rapid growth and can cause symptoms due to local mass effect. Surgical management of symptomatic or growing pediatric RCCs via cyst fenestration or partial resection of the cyst wall can be performed safely, with good neurologic outcomes. There is a nontrivial risk of endocrinologic injury, and long-term follow up is needed due to high recurrence rates.

Pediatric sellar teratoma - Case report and review of the literature

BACKGROUND

Intracranial teratoma represents a rare neoplasm, occurring predominantly during childhood. Characteristic symptoms depend on the location but are mainly hydrocephalus, visual disturbances, hypopituitarism, and diabetes insipidus. Initial diagnosis can be challenging due to similar radiological features in both teratomas and other lesions such as craniopharyngiomas. Gross total resection is recommended if feasible and associated with a good prognosis.

CASE DESCRIPTION

A 10-year-old girl presented with newly diagnosed growth retardation, fatigue, cephalgia and bilateral hemianopia. Further laboratory analysis confirmed central hypothyroidism and hypercortisolism. Cranial magnetic resonance imaging showed a cystic space-occupying lesion in the sellar and suprasellar compartment with compression of the optic chiasm without hydrocephalus present, suspicious of craniopharyngioma. Subsequently, an endonasal endoscopic transsphenoidal near-total tumor resection with decompression of the optic chiasm was performed. During postoperative recovery the patient developed transient diabetes insipidus, the bilateral hemianopia remained unchanged. The patient could be discharged in a stable condition, while hormone replacement for multiple pituitary hormone deficiency was required. Surprisingly, histopathology revealed conspicuous areas of skin with formation of hairs and squamous epithelia, compatible with a mature teratoma.

CONCLUSIONS

We present an extremely rare case of pediatric sellar teratoma originating from the pituitary gland and a review of literature focusing on the variation in presentation and treatment. Sellar teratomas are often mistaken for craniopharyngioma due to their similar radiographic appearances. However, the primary goal of treatment for both pathologies is to decompress eloquent surrounding structures such as the optic tract, and if applicable, resolution of hydrocephalus while avoiding damage to the pituitary stalk and especially the hypothalamic structures. If feasible, the aim of surgery should be gross total resection.

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.

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.

Incidence of Sinus Inflammation After Endoscopic Skull Base Surgery in the Pediatric Population

BACKGROUND

The extended endonasal approach has been utilized in the resection of anterior skull base lesions in the pediatric population. There are unique challenges to these patients in the post-operative setting, including patient compliance with medical therapy and post-operative debridements, and a smaller nasal airway that may increase propensity toward scarring. Our objective for this study is to evaluate the incidence of post-operative radiographic inflammation in this patient population using the Lund-Mackay (LM) score.

METHODS

A single-center, retrospective review of pediatric patients undergoing endoscopic approach to the skull base between 2009 and 2021 was performed. Demographic and clinicopathologic data and pre- and post-operative imaging were analyzed. One-way ANOVA followed by Tukey multiple pairwise comparisons statistical tests were used to compare mean LM scores between groups.

RESULTS

Seventy-two patients (52 males, 20 females) were identified with a median follow-up of 27 months. All patients underwent an extended endonasal approach for resection of skull base lesions. The mean LM scores were compared between pre-operative MRI, first post-operative MRI > 30 days after surgery, and most recent post-operative MRI. One-way ANOVA was performed with significant differences noted between the groups (p < 0.001). Tukey multiple pairwise comparisons test was then performed and noted significant differences between the pre-operative and first post-operative LM (p < 0.0001) and the first post-operative and most recent LM (p < 0.0001). There was no significant difference noted between the pre-operative LM score and most recent LM score (p = 0.14).

CONCLUSION

Despite concerns regarding possible subsequent development of chronic rhinosinusitis following endoscopic skull base surgery in pediatric patients, the current study suggests that transient radiographic evidence of sinus inflammation can be seen up to six months postoperatively, which appears to resolve by approximately two years after surgery.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

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 extended transsphenoidal surgery for newly diagnosed paediatric craniopharyngiomas

PURPOSE

Endoscopic extended transsphenoidal surgery (EETSS) has gained popularity for treatment of craniopharyngiomas. The aim of this study is to assess the outcome of endoscopic extended transsphenoidal surgery (EETSS) for newly diagnosed paediatric craniopharyngiomas.

METHODS

Patient details were obtained from a prospective database of all endoscopic transnasal operations performed by a single surgeon. Outcomes including visual function, pituitary function, body mass index (BMI), postoperative neurological deficit, extent of resection and recurrence on follow-up were obtained. Obesity was defined as BMI percentile of equal to or greater than 95%.

RESULTS

Between January 2011 and January 2020, 15 of 16 children (5-18 years old) with newly diagnosed craniopharyngiomas underwent EETSS. Four patients had a conchal-type sphenoid sinus. Gross total resection (GTR) was achieved in 4 patients and near total resection (NTR) in 5 patients. The remaining 6 had subtotal resection (STR). Postoperative radiotherapy was used in 6 patients (4 with STR, 2 with NTR). There were no postoperative deaths, strokes or CSF leaks. Normalisation of visual fields (VF) occurred in 9/13 patients with preoperative VF defects. One patient developed a new visual field defect. During a median follow-up period of 74 (8-104) months, 2 patients have required further surgery for tumour progression following initial STR, where a tumour remnant was left in situ to preserve the pituitary stalk. 6/11 patients developed new anterior pituitary dysfunction as a result of surgery and 9/12 developed new diabetes insipidus (DI). At the time of last follow-up, 14/15 children had anterior panhypopituitarism, 13/15 had DI and 1 patient developed new onset obesity. Two patients, who were obese preoperatively, were no longer obese at last follow-up.

CONCLUSIONS

EETSS can be performed as the first option in the majority of children with newly diagnosed craniopharyngioma, despite factors such as small nose, non-pneumatised sphenoid sinus, small sella or purely suprasellar tumour location. Preservation of the pituitary stalk at the expense of leaving residual tumour may not be in the best interests of the patient.

Intercarotid artery distance in the pediatric population: Implications for endoscopic transsphenoidal approaches to the skull base

OBJECTIVE

Comprehensive quantitative evaluation of the intercarotid artery distance (ICD) in the pediatric population has not been sufficiently explored. This study aims to measure the minimal ICDs at multiple levels of the skull base to assess changes in the ICD during development.

METHODS

Measurement of the ICDs between the paired paraclival, parasellar, and paraclinoid segments of the internal carotid artery (ICA) was performed on coronal MRI from 540 patients ranging from 0 to 17 years old (n = 30 for each age). Comparison of these indices in the very young (0-5 years, Group 1) and young (6-17 years, Group 2) patients, and assessment of the degree of sphenoid sinus pneumatization was employed.

RESULTS

The narrowest ICD was located at the paraclinoid ICAs in the vast majority of cases (89.44%). When comparing the ICDs in very young age patients with the ICDs of 17 years old subjects, a statistically significant difference was found at the paraclival (ages 0-5), parasellar (ages 0-2), and paraclinoid (ages 0-4) ICDs (p < 0.05). Comparison of the ICDs between the intergroups (Group 1 and 2) also demonstrated a statistically significant difference (p < 0.0001). Pneumatization of the sphenoid sinus was initially noted to start at 3 years of age, and there were no patients with a non-pneumatized sphenoid sinus identified after 7 years of age in our cohort.

CONCLUSION

Measurement of ICDs at multiple levels provides a valuable reference for EEA procedures in the pediatric population. While the ICD may be largely stable in the pediatric population after 5 years of age, additional anatomic factors may restrict transsphenoidal access in very young patients (0-5 years).

Enhancing access to the suprasellar region: the transcallosal translamina terminalis approach

Craniopharyngioma represents one of the most challenging brain tumors to treat. Surgery may be the definitive treatment, and multiple surgical approaches have been described, each based on different anatomical considerations. Some approaches require working through narrow corridors that do not often provide a sufficient view of the critical anatomical structures around the tumor. The choice of the right approach is key for optimizing resection and minimizing risk. In this paper, the author presents the case of a pediatric patient with a large suprasellar craniopharyngioma who underwent complete resection of the tumor through a novel approach: a transcallosal translamina terminalis corridor. This particular transcallosal corridor, behind the anterior communicating artery, allows the optimal opening of the lamina terminalis extending up to the anterior commissure. This novel variation of the traditional operation provides a wider exposure of the tumor compared with the classic approaches through the lamina terminalis. This technique has not been sufficiently described in the pediatric literature. The author describes it here as an alternative method for treating patients with sellar and suprasellar tumors.