Endoscopic Resection of Pediatric Skull Base Tumors: An Evidence-Based Review

Neuroendoscopy: intraventricular and skull base tumor resection in children

During the last 30 years, the neurosurgeons have witnessed a revolution in the practice of interventricular surgery. The advent of neuroendoscopy at the end of the 1980s has allowed a minimally invasive management of a very large series of pathologies in pediatric neurosurgery ranging from hydrocephalus to arachnoid cyst to intraventricular tumors. The progresses in the management of hydrocephalus, intracranial cyst, and the fluid filled collection nevertheless has been more rapid and radical due to the simpler equipment that is necessary to perform this kind of surgery. The intraventricular tumors instead have been addressed in a slower way, and for many years, the only endoscopic procedure that was allowed on interventricular tumors was a biopsy associated with the management of hydrocephalus. Only very small tumors have been considered operable for complete removal during many years due to the limitations of the neuroendoscopic equipment and to the small calibers of the working channel. More recently, the advent of new devices and new surgical techniques are offering new perspectives on the possibility of intraventricular tumor surgery in children. In this review, we describe the historical perspective of the learning curve of intraventricular tumor surgery under neuroendoscopic control and try to offer a view of the future perspective in the removal of larger intraventricular tumors, analyzing the main indications for intraventricular endoscopic tumor surgery. We offer as well an historical perspective of the evolution of skull base surgery and endonasal transsphenoidal approach for skull-based tumors in children. This kind of surgery that has acquired widespread acceptance for many pathologies in adult age has diffused more slowly in pediatric neurosurgery due to the anatomical limitation observed in these age range. Also in this field, the slow evolution of the technique and of the technology available to neurosurgeons has allowed a very significant expansion of indication for the minimally invasive removal of skull base tumors in children.

Triple Layer Oronasal Fistula Repair Using Local Endonasal Flaps: Case Series of Three Patients

Oronasal fistula (ONF) is a common complication encountered after palatoplasty. Repair is indicated when symptoms impact speech and swallowing. In spite of the variety of surgical approaches described to repair these defects, recurrence rates remain high. Traditionally, successful closure is said to be achieved in using a double-layered approach due to the three-dimensional aspect of the defect. The extent of the fistula into the nasal cavity has incited an increased curiosity in using local endonasal flaps. In recent years, endonasal reconstructive procedures have seen increased interest and application, from cranial base defect repairs to orbital reconstruction and beyond. The nasoseptal (NSF) and inferior turbinate flaps (ITF) possess a robust arterial supply and an exceptional reach with excellent results demonstrated in large defect repair. However, the use of these flaps in ONF repair is scarcely discussed in the literature, and their effectiveness is relatively undetermined. In this manuscript, we present a series of three patients who underwent a triple layer ONF closure, with the oral portion incorporating a turn-in mucosal flap plus a local palate rotation flap or greater palatine artery pedicled-rotation flap, and a NSF or an ITF for the nasal portion of the defect.

Pediatric Endoscopic Endonasal Skull Base Surgery: A Retrospective Review Over 11 Years

OBJECTIVE

To show the safety and efficacy of the endoscopic endonasal approach (EEA) for skull base surgery in pediatric patients through descriptive analysis of cases over an 11-year period.

METHODS

The study comprised 94 patients undergoing EEA for skull base surgery, between January 2007 and June 2018, at 2 tertiary pediatric hospitals. Descriptive statistics are presented regarding the presentation, intraoperative details, and complications.

RESULTS

Over the study period, 130 surgeries were performed in 94 patients: 94 primary surgeries and 36 reoperations. The mean patient age was 13.8 years and 48.9% of patients were female. Presenting signs/symptoms included endocrinopathies (56.4%), vision abnormalities (37.2%), and cranial nerve deficits (20.2%). EEA alone was used in 95.7% of primary surgeries and 91.7% of reoperations. Diseases treated included craniopharyngioma (18.1%), pituitary adenoma (17.0%), Rathke cleft cyst (13.8%), chordoma (9.6%), osteosarcoma (5.3%), juvenile nasopharyngeal angiofibroma (4.3%), skull base fracture (4.3%), and encephalocele (3.2%). A lumbar drain was used in 20.2% of primary surgeries and 25% of reoperations. A nasoseptal flap was used in 36.2% of primary surgeries and 25% of reoperations. Postoperative complications included cerebrospinal fluid leak (12.8%), sinusitis (7.4%), bacterial meningitis (3.2%), and carotid artery injury in 1 reoperation.

CONCLUSIONS

EEA for anterior cranial base disease is safe and efficacious in pediatric patients and can be used to treat many of the rare and heterogenous diseases that arise in this anatomic location. Management strategies and rates of sinonasal and intracranial complications including cerebrospinal fluid leak rate are similar to those reported in adult cohorts.

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.

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.

Sinonasal Symptom Outcomes following Endoscopic Anterior Cranial Base Surgery in the Pediatric Population

Objective This study aimed to evaluate the impact of endoscopic anterior cranial base (ACB) surgery on sinonasal symptoms in the pediatric population utilizing the Sino-Nasal Outcome Test (SNOT)-22 questionnaire.

Design This is a retrospective review.

Setting The study was conducted at a tertiary academic medical center.

Participants Thirty-four consecutive patients, age 6 to 17 years, M:F 14:20, who underwent endoscopic ACB surgery from July 2008 to August 2019. Ten patients had baseline and a minimum of two subsequent postoperative SNOT-22 questionnaires available for analysis.

Main Outcome Measures Baseline and postoperative SNOT-22 scores were compared. The mean change from baseline sinonasal symptom scores in the pediatric and historical adult cohorts was compared.

Results The mean baseline SNOT-22 score for our 10 patient cohort was 0.46 out of 5 for each of the first 10 sinonasal-specific questions. This worsened to 1.69 at 1 month and returned to near baseline, 0.7, at 3 months postoperatively. The mean quality-of-life score improved to 0.91 at 1 month and 0.6 at 3 months postoperatively. The mean change from baseline for the following items: need to blow nose, runny nose, postnasal discharge, thick nasal discharge, wake up at night, reduced concentration, and frustrated/restless/irritable were similar to those in our historical adult cohort at 3 months postoperatively.

Conclusion Endoscopic ACB surgery in the pediatric population results in increased sinonasal symptom morbidity in the early postoperative period; however, symptoms return to near baseline by ∼3 months, and quality-of-life scores progressively improve in the postoperative period. These trends were similar to those seen in our historic adult cohort.

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).

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.