Surgical Relevance of Pediatric Anterior Clinoid Process Maturation for Anterior Skull Base Approaches

Impact of nasal septum deviation on the sphenoid bone pneumatization: a retrospective computed tomography study

BACKGROUND

Deviated nasal septum (DNS) changes aerodynamic airflow pattern and increases nasal resistance that may affect paranasal sinus pneumatization.

OBJECTIVES

To explore the relationships among DNS, sphenoid bone pneumatization and surrounding neurovascular structures.

MATERIAL AND METHODS

The paranasal sinus CT images of DNS patients (n = 100) and patients without DNS (n = 60) between 2020 and 2022 were retrospectively analyzed. Sphenoid bone pneumatization and anterior clinoid processes (ACP) length were measured while surrounding neurovascular structure types were assessed.

RESULTS

In the DNS group, the indicators demonstrating sphenoid bone pneumatization were significantly (p < 0.001) greater than that in the control group. There were no statistically significant differences in the indicators demonstrating the positions of vidian canal (VC) and foramen rotundum (FR) between two groups. Regarding proportion of different neurovascular structure grades, the findings were significant (p < 0.05) between two groups. The corrected sphenoid sinus area also correlated with surrounding neurovascular structure types.

CONCLUSIONS AND SIGNIFICANCE

Severe DNS is significantly related to the sphenoid bone pneumatization and surrounding neurovascular structure. This suggests that clinicians should be aware of the anatomical variation of sphenoid bone pneumatization and the cranial base structures in DNS patients.

Closure of small skull base defects with muscle plug napkin ring technique: how I do it

BACKGROUND

Defects through the skull base into the paranasal sinuses can occur during anterior skull base procedures, risking cerebrospinal fluid leak and infection if not repaired.

METHODS

We describe a muscle plug napkin ring technique for closure of small skull base defects, wherein a free muscle graft slightly bigger than the defect is packed tightly in the defect, half extracranially and half intracranially and sealed with fibrin glue. The technique is illustrated in the case of a 58-year-old woman with a large left medial sphenoid wing/clinoidal meningioma.

CONCLUSIONS

The muscle plug napkin ring technique is a simple solution to small skull base defects.

Maturation of the internal auditory canal and posterior petrous bone with relevance to lateral and posterolateral skull base approaches

Anatomic knowledge of the internal auditory canal (IAC) and surrounding structures is a prerequisite for performing skull base approaches to the IAC. We herein perform a morphometric analysis of the IAC and surgically relevant aspects of the posterior petrous bone during pediatric maturation, a region well-studied in adults but not children. Measurements of IAC length (IAC-L), porus (IAC-D) and midpoint (IAC-DM) diameter, and distance from the porus to the common crus (CC; P-CC) and posterior petrosal surface (PPS) to the posterior semicircular canal (PSC; PPS-PSC) were made on thin-cut axial CT scans from 60 patients (grouped by ages 0–3, 4–7, 8–11 12–15, 16–18, and > 18 years). IAC-L increased 27.5% from 8.7 ± 1.1 at age 0–3 to 11.1 ± 1.1 mm at adulthood (p = 0.001), with the majority of growth occurring by ages 8–11. IAC-D (p = 0.52) and IAC-DM (p = 0.167) did not significantly change from ages 0–3 to adult. P-CC increased 31.1% from 7.7 ± 1.5 at age 0–3 to 10.1 ± 1.5 mm at adulthood (p = 0.019). PPS-PSC increased 160% from 1.5 ± 0.7 at age 0–3 to 3.9 ± 1.2 mm at adulthood (p < 0.001). The majority of growth in P-CC and PPS-PSC occurred by ages 12–15. Knowledge of these patterns may facilitate safe exposure of the IAC in children.

Maturation of the sella turcica and parasellar region: Surgical relevance for anterior skull base approaches in pediatric patients

OBJECTIVE

Traditional and extended transnasal transsphenoidal approaches provide direct access to a variety of anterior skull base pathologies. Despite increased utilization of transnasal approaches in children, anatomic studies on pediatric skull base maturation are limited. We herein perform a surgically relevant morphometric analysis of the sella and parasellar regions during pediatric maturation.

METHODS

Measurements of sellar length (SL), sellar depth (SDp), sellar diameter (SDm), interclinoid distance (ID), intercavernous distance (ICD), and the presence of sphenoid sinus pneumatization (SSP), and sphenoid sinus type (SST) were made on thin-cut CT scans from 60 patients (evenly grouped by ages 0-3, 4-7, 8-11 12-15, 16-18, and >18 years) for analysis. Data were analyzed by sex and age groups using t-tests and linear regression.

RESULTS

Sella and parasellar parameters did not differ by sex. SL steadily increased from 8.5 ± 1.2 mm to 11.5 ± 1.6 mm throughout development. SDp and SDm increased from 6.0 ± 0.9 mm to 9.3 ± 1.4 mm and 9.0 ± 1.6 mm to 14.4 ± 1.8 mm during maturation, with significant interval growth from ages 16-18 to adult (p < 0.01). ID displayed significant growth from ages 0-3 to 4-7 (18.0 ± 2.4 mm to 20.7 ± 1.9 mm; p = 0.002) and ICD from ages 0-3 to 8-11 (12.0 ± 1.8 mm to 13.5 ± 2.1 mm; p < 0.001), without further significant interval growth. SSP was not seen in patients < 3, but was 100% by ages 8-11. SSTs progressed from conchal/presellar (60% at ages 4-7) to sellar/postsellar (80% at adulthood).

CONCLUSION

The sella and parasellar regions have varied growth patterns with development. Knowledge of the expected maturation of key anterior skull base structures may augment surgical planning in younger patients.