Lateral lamella of the cribriform plate: software-enabled computed tomographic analysis and its clinical relevance in skull base surgery.

OBJECTIVE To describe a quantitative analysis of the lateral lamella of the cribriform plate (LLCP) height in computed tomographic (CT) images. The LLCP is the thinnest anatomic structure in the skull base. DESIGN Software-enabled CT scan measurements. SETTING Academic center. RESULTS The CT scans from 50 patients were analyzed. The median height of the LLCP in 100 sides was 2.4 mm. The LLCP height was 0 to 3.9 mm in 83 sides, 4.0 to 7.0 mm in 15 sides, and greater than 7.0 mm in 2 sides. When analyzing differences among sides, the LLCP height was greater on the right side in 28 patients and greater on the left side in 22. The differences between sides was 0 to 1.9 mm in 39 patients, 2.0 to 3.9 mm in 9 patients, and greater than 4.0 mm in 2 patients. CONCLUSIONS Computer-aided CT scan analysis allows for a quantitative analysis of the paranasal sinus skull base anatomy. Knowledge of these dimensions is invaluable during surgical planning and navigation. Asymmetry of the relative ethmoid roof position is common. Thus, the rhinologic surgeon must exercise caution to prevent unintentional skull base injury and cerebrospinal fluid leak.