Morphometric analysis of Kocher's and Frazier's points in a small sample taken from the South African scaphocephalic paediatric population: A preliminary study

Abstract

IntroductionDue to varying cranial morphologies, ventricular access in patients with craniosynostosis using conventional techniques is often a challenge. Although ventricular access may not be frequently required in scaphocephalic patients, it is vital that an ideal location of the access points be established for safe ventricular catheterization. This study aimed to document the morphometry of commonly used ventricular access points, i.e. Kocher's and Frazier's points, within a select South African scaphocephalic paediatric population. MethodsThe craniometric dimensions of Kocher's and Frazier's points were measured relative to anatomical and craniometric landmarks on pre-operative computed tomography scans of 24 consecutive patients diagnosed with scaphocephaly between 2014 and 2020. Results were compared against age, sex, population group and the degree of severity of the deformity. ResultsKocher's point was located between 91.6 mm and 140.0 mm posterior to the nasion, and between 20.5 mm and 34.6 mm lateral to the midline. Statistically significant increases were reported in the mean distance posterior to nasion between patients in the <1 year and older age groups (>1-<9 years) (ANOVA, p < 0.001); and in the mean distance lateral to the midline (ANOVA, p = 0.004), between patients in the <1 year and 3-<6-year (post-hoc, p = 0.002) and 1-<3-year and 3-<6-year (post-hoc, p = 0.030) age groups, respectively. Frazier's point was located between 60.9 mm and 82.8 mm superior to the inion, and 25.9 mm and 41.4 mm lateral to the midline. No statistically significant differences were documented for comparisons by sex, population group and degree of severity in the tested sample. ConclusionsThe study found that the traditional landmarks used for ventricular access can be unreliable in scaphocephalic patients, particularly in those less than one year of age. Parameters measured in the anteroposterior plane were more affected than those measured lateral from the midline. This study provides novel morphometric data for neurosurgical consideration regarding ventricular catheterization procedures in scaphocephalic patients.