Gender and Population Variation in Craniometry and Freehand Pass Ventriculostomy.

BACKGROUND: Ventriculostomy using the freehand pass method is subject to complications arising from misplacement of the catheter tip. This method may require multiple passes for successful catheterization. Methods of determining the burr-hole location (known as the Kocher point) were derived historically from European patients and may not be appropriate for other populations with different cranial shapes. This study examines the possibility that anatomic variation in interpopulation variation together with sexual dimorphism in cranial size and shape may contribute to this problem.

METHODS: Sagittal and parasagittal measurements of the frontal bone were taken of 300 Thai (150 female, 150 male) crania and 300 American white (150 female, 150 male) crania. These measurements were compared to determine sexual dimorphism and interpopulation variation in size and shape.

RESULTS: The measurements were statistically significantly larger in males than in females and on the right side than the left in both sexes in both Thai and American white samples. The frontal bone is significantly longer at the sagittal plane in Europeans of both sexes than in Thai, but in the parasagittal plane, there is no difference. This finding indicates a difference in frontal bone shape between the 2 populations and between males and females.

CONCLUSIONS: The dimensions of the frontal bone vary between males and females and can vary among populations. The optimal location for the burr hole in freehand pass ventriculostomy may depend on both the gender and the ancestry of the patient.