Mullan's triangle or anteromedial triangle of the middle cranial fossa: a cadaveric study with its surgical importance.

Abstract

Surgical approaches to the cavernous sinus (CS) and middle cranial fossa (MCF) can be challenging, particularly for young neurosurgeons. The anteromedial (Mullan's) triangle is a triangle by the side of the CS and constitutes part of the floor of the MCF. The contents include the sphenoid sinus, superior ophthalmic vein, and sixth cranial nerve. The literature contains very little research that has precisely defined and measured the anteromedial triangle while considering anatomical variances minimally. The present study was conducted on the skulls of 25 adult human cadavers which were dissected to expose the anteromedial (Mullan's) triangle on both sides. After precisely defining the triangle on each side, measurements of the three borders were taken, and using Heron's formula, the area of each triangle was calculated. On average, the length of the medial border was 12.5 (+ 3.1mm); the length of the lateral border was 9.9 (+ 3.1mm); the length of the base was 10.75 (+ 2.4mm) and the area of the anteromedial triangle was 43.9 (+ 15.06mm2). Precise anatomical knowledge of the Mullan's triangle enables the treatment of disorders in often deformed anatomy or difficult-to-access structures. That is the reason it is important to gain a thorough understanding of the surgical anatomy and to adopt a safe procedure.