An endoscopic endonasal approach for the surgical repair of transsphenoidal cephalocele in children

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.

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.

Endoscopic Transnasal Skull Base Surgery in Pediatric Patients

Introduction  In pediatric patients, endoscopic transnasal surgery (ETNS) poses challenges because of the small size of the developing skull and narrow endonasal corridors. Objective  This study aimed to evaluate the efficacy of ETNS in children by assessing our experience of endoscopic skull base surgery. Materials and Methods  All pediatric patients ( n  = 54) who were eligible for surgery using only the endonasal endoscopic approach at our tertiary center between 2012 and 2018 were included in this study. The surgeries were performed simultaneously by an endoscopic skull base team of neurosurgeons and otolaryngologists. Hormonal analyses were conducted before and after surgery in all patients with sellar/parasellar lesions. Patients older than 8 years underwent smell and visual testing. Results  In the 54 patients aged 1 to 17 years who underwent surgery, craniopharyngioma was the most common pathology (29.6%), followed by pituitary adenoma (22.2%). Gross total resection was achieved in 33 (76.7%) of 41 patients who underwent surgery because of the presence of tumors. All visual deficits improved, although one patient sustained olfactory deterioration. Sixteen (29.6%) patients presented with complications such as transient diabetes insipidus and temporary visual loss. Conclusions  Despite anatomy-related challenges in children, adequate results can be achieved with high rates of success, and the functional and anatomical integrity of the developing skull and nose of children can be preserved. In pediatric patients, ETNS is a safe and effective option for addressing various lesions along the skull base.

[Modern diagnosis and treatment in children with congenital basal encephalocele]

Basal encephalocele is a rare disease that predominantly occurs in children. Its most common symptoms include nasal liquorrhea, difficulty in nasal breathing, and deformity of the naso-orbital region.

MATERIAL AND METHODS

The study group included 19 patients with basal encephalocele, aged 2 months to 18 years. Ten (59%) patients were operated on through a transnasal endoscopic approach; 3 (17.5%) patients were operated on through a transcranial approach; 4 (23.5%) patients were operated on using a combined approach: the patients underwent simultaneous elimination of a cranio-orbital region deformity using the basal transcranial approach as well as hernial sac resection and hernioplasty using the transnasal endoscopic approach. Two children had no surgery due to minimal symptoms and a lack of cerebrospinal fluid leak.

RESULTS

Application of the algorithms for diagnosis and treatment of encephalocele, suggested by the authors, enabled making the timely diagnose, defining the optimal surgical tactics, and achieving good treatment results.

CONCLUSION

A differentiated approach to the choice of a surgical technique for basal encephalocele, the use of auto-tissues for skull base reconstruction, intraoperative and postoperative lumbar drainage, and simultaneous elimination of deformity of the fronto-naso-orbital region enable avoiding complications and achieving good functional and aesthetic results.