The Inferolateral Surgical Triangle of the Cavernous Sinus: A Cadaveric and MRI Study with Neurosurgical Significance

The inferolateral triangle is a surgical skull base triangle used as a neurosurgical landmark. There are few reports of its measurements with little attention paid to anatomic variations. The inferolateral triangle was measured in 10 adult human cadaveric heads via dissection then direct measurement and 5 participants undergoing neuroimaging using tracing features. In the cadavers, mean lengths (mm) of the superior, anterior, and posterior borders were 17.0 (±5.5), 12.9 (±1.7), and 17.8 (±3.3), respectively, with mean area of 97.85 (±28.17) mm2. In the participants, mean lengths (mm) of the superior, anterior, and posterior borders were 17.35 (±4.01), 14.36 (±1.36), and 18.01 (±2.43), respectively, with mean area of 113.6 (±25.46) mm2. No statistical difference in triangle areas between groups was found. Intimate understanding of the inferolateral triangle is essential to skull-based surgery; knowing its anatomy and variations aids in surgical planning and understanding of regional pathology.