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Published on: July 5, 2021
Surgical Relevance of Pediatric Anterior Clinoid Process Maturation for Anterior Skull Base Approaches
Robert C Rennert1, Michael G Brandel1, Jeffrey A Steinberg1
1Department of Neurological Surgery, University of California, San Diego, La Jolla, California.
Insights
The anterior clinoid process (ACP) shows stable thickness but complex growth patterns during childhood and adolescence. Understanding these developmental changes and variations is crucial for pediatric skull base surgery.
Area of Science:
- Neurosurgery
- Pediatric anatomy
- Skull base surgery
Background:
- The anterior clinoid process (ACP) is key for surgical access to the anterior skull base.
- Detailed understanding of pediatric ACP development and variations is limited.
Purpose of the Study:
- To conduct a morphometric analysis of the anterior clinoid process (ACP) throughout pediatric maturation.
Main Methods:
- High-resolution CT scans of 60 patients (0-18+ years) were analyzed for ACP dimensions and variations.
- Measurements included thickness, length, pneumatization, and ossified ligaments.
- Statistical analysis involved t-tests and linear regression, stratified by age, sex, and laterality.
Main Results:
- No significant differences in ACP parameters were observed based on laterality or sex.
- ACP thickness remained stable, while length increased significantly in two phases (0-3 to 8-11 years and 16-18 years to adult).
- Anatomical variations like ossified carotico-clinoid ligament (OCCL) and interclinoid ligament (OIL) were present from age 3, while ACP pneumatization was seen from age 11.
Conclusions:
- The anterior clinoid process (ACP) exhibits stable thickness and a triphasic growth pattern during development.
- Understanding these morphometric changes and variations is vital for safe surgical removal in pediatric patients.
- Clinically significant ACP variations can manifest at any age.
Background:
Removal of the anterior clinoid process (ACP) can expand anterior skull base surgical corridors. ACP development and anatomical variations are poorly defined in children.
Objective:
To perform a morphometric analysis of the ACP during pediatric maturation.
Methods:
Measurements of ACP base thickness (ACP-BT), midpoint thickness (ACP-MT), length (ACP-L), length from optic strut to ACP tip (ACP-OS), pneumatization (ACP-pneumo), and the presence of an ossified carotico-clinoid ligament (OCCL) or interclinoid ligament (OIL) were made from high-resolution computed-tomography scans from 60 patients (ages 0-3, 4-7, 8-11 12-15, 16-18, and >18 yr). Data were analyzed by laterality, sex, and age groups using t-tests and linear regression.
Results:
There were no significant differences in ACP parameters by laterality or sex, and no significant growth in ACP-BT or ACP-MT during development. From ages 0-3 yr to adult, mean ACP-L increased 49%, from 7.7 to 11.5 mm. The majority of ACP-L growth occurred in 2 phases between ages 0-3 to 8-11 and ages 16-18 to adult. Conversely, ACP-OS was stable from ages 0-3 to 8-11 but increased by 63% between ages 8-11 to adult. Variations in ACP morphology (OCCL/OIL/ACP-pneumo) were found in 15% (9/60) of scans. OCCL and OIL occurred in patients as young as 3 yrs, whereas ACP-pneumo was not seen in patients younger than 11 yrs.
Conclusion:
The ACP demonstrates stable thickness and a complex triphasic elongation and remodeling pattern with development, the understanding of which may facilitate removal in patients <12. Clinically relevant ACP anatomic variations can occur at any age.
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