Mapping the Filipino Pediatric Skull Base: A Computed Tomography-Based Analysis of Anatomical Parameters and Nasoseptal Flap Reconstruction Feasibility from a Single Tertiary Hospital in the Philippines

Abstract

Objective: To establish radiographic baseline measurements of key anatomical parameters of the Filipino pediatric skull base using computed tomography (CT); compare these anatomical parameters across different pediatric age groups and between sexes; and determine the feasibility of nasoseptal flap reconstruction for sellar defects in a Filipino pediatric population by calculating the nasoseptal flap to sellar defect length ratio (NSR).

Methods:
Design: Review of Records
Setting: Tertiary Academic Medical Center
Participants: Digital Imaging and Communications in Medicine (DICOM) images of patients aged 0-17 years who had high-resolution head CT scans done at the University of Santo Tomas Hospital during the period of January 2019 – January 2024 were retrieved and reviewed. The following measurements were obtained: piriform aperture width (PAW), nare to sella distance (NSD), sphenoid to sella distance (SSD), sphenoid pneumatization type (SP), sphenoid sinus width (SW), olfactory fossa depth (OFD), lateral lamella cribriform plate angles (CPA), intercarotid distances (ICD) at the superior clivus (ICD-SC) and cavernous sinus (ICD-CS), potential nasoseptal flap length (NSF), potential sellar defect length (SDL) and nasoseptal flap length to sellar defect length ratio (NSR). Participants were stratified into three age groups (<5years, 5-12 years, 13 years and older), and sex (males, females). Between-group comparisons were performed using ANOVA, chi-square and independent t-tests (α = 0.05).

Results: Among the 111 participants (median age 12 years, IQR 7-15), 63.06% were males. For children <5 years (n = 23), mean values were: PAW 1.82 ± 0.15 cm, NSD 5.84 ± 0.37 cm, SSD 1.40 ± 0.35 cm, SW 1.78 ± 0.44 cm, OFD 0.53 ± 0.18 cm, ICD-SC 1.04 ± 0.20 cm, ICD-CS 1.64 ± 0.18 cm, NSF 4.95 ± 0.45 cm, and SDL 4.21 ± 0.64 cm. For ages 5-12 years (n = 39), values were: PAW 2.06 ± 0.23 cm, NSD 6.71 ± 0.50 cm, SSD 1.67 ± 0.24 cm, SW 2.55 ± 0.54 cm, OFD 0.61 ± 0.16 cm, ICD-SC 1.19 ± 0.21 cm, ICD-CS 1.86 ± 0.18 cm, NSF 5.63 ± 0.59 cm, and SDL 4.70 ± 0.85 cm. For ages ≥13 years (n = 49), values were: PAW 2.21 ± 0.26 cm, NSD 7.22 ± 0.63 cm, SSD 1.86 ± 0.33 cm, SW 3.04 ± 0.66 cm, OFD 0.64 ± 0.23 cm, ICD-SC 1.23 ± 0.26 cm, ICD-CS 1.92 ± 0.24 cm, NSF 6.50 ± 0.50 cm, and SDL 5.59 ± 0.90 cm. Most participants had sellar-type sphenoid pneumatization (n = 48, 43.24%) and Type 2 Keros classification (n = 74, 66.67%). Sphenoid pneumatization differed significantly across age groups (p = .001), with conchal type predominant in <5 years (n = 22, 95.65%), presellar in 5-12 years (n = 18, 46.15%), and sellar in ≥13 years (n = 38, 77.55%). The mean nasoseptal flap to sellar defect ratio (NSR) was 1.21 ± 0.22 overall and did not differ across age groups (p = .677), indicating adequate flap length for reconstruction across all ages.

Conclusion: In this sample, Filipino pediatric skull base anatomy demonstrates significant age-related dimensional changes but no sex-dependent differences. Despite smaller absolute dimensions in younger children, nasoseptal flap reconstruction appears radiographically feasible across all pediatric age groups. Our findings provide population-specific normative data to guide preoperative planning for pediatric endoscopic endonasal skull base surgery.