Are orbital branches of the middle meningeal artery underestimated? A human cadaveric angiographic study.

Abstract

ObjectiveUnderstanding anatomical variations of the middle meningeal artery (MMA), particularly the meningolacrimal anastomosis (MLA), is essential for the safe execution of MMA embolization (MMAe) procedures. Due to the small size of these dural branches, detailed anatomical dissections have been challenging, and conventional clinical angiography often underrepresents their frequency because of competing orbital blood flow. This study aimed to determine the prevalence and anatomical characteristics of the MLA using isolated high-resolution angiography and DynaCT in human cadaveric specimens.MethodsA prospective angiographic study was conducted in eight fresh human cadaveric specimens. Microcatheters were navigated into proximal MMA branches, followed by contrast injection and imaging with angiography and DynaCT. MLA identification, length, diameter, and branching patterns were recorded. Descriptive statistics were used to analyze anatomical characteristics.ResultsThe MLA was visualized in 15 of 16 (93.7%) MMAs. A single MLA was observed in 87.5% of cases; one specimen showed two branches. The mean length of the intradural segment of the MLA (from the origin at the MMA to the entry into the orbit) was 1.77 ± 0.70 cm. The mean diameter of the MLA was 0.93 ± 0.29 mm, and the MMA diameter at the origin of the MLA measured 2.15 ± 0.51 mm. There were no statistically significant differences between genders in any of the parameters.ConclusionsOrbital branches of the MMA, particularly the MLA, are more prevalent than previously appreciated in standard angiography. This has significant implications for the safety of MMAe. Cadaveric angiography may reveal critical anastomoses underrepresented in in vivo imaging, underscoring the need for anatomical vigilance during embolization.