Related Experiment Video
Updated: Mar 9, 2026
Endolymphatic Duct Blockage as a Surgical Treatment Option for Ménière's Disease
Published on: April 28, 2023
A Systematic Review With Meta-analysis of the Mastoid Emissary Foramen: Implications for Posterior Cranial Fossa
Ibrahim Alzir1, George Triantafyllou1, Sabino Luzzi2
1Department of Anatomy, School of Medicine, Faculty of Health Sciences, National and Kapodistrian University of Athens, Greece.
Introduction:
The mastoid emissary foramen (MEF), transmitting the mastoid emissary vein, is a key anatomical structure encountered during posterior cranial fossa and cerebellopontine angle approaches. Injury to this variable venous pathway may result in significant hemorrhage. However, published data regarding the prevalence and morphology of the MEF remain inconsistent.
Methods:
A systematic review with meta-analysis was conducted according to PRISMA 2020 and Evidence-based Anatomy guidelines. Four databases were searched for osteological and imaging studies reporting MEF prevalence or morphometry were included. Pooled prevalence and morphometric estimates were calculated using random-effects models.
Results:
Twenty-one studies comprising 8689 skull sides were included. The pooled prevalence of the MEF was 74% (95% CI: 65.16-82.03), with absence in 26%. A single MEF was most common (53%), while multiple MEFs were present in 16% of cases. Two, three, and four MEFs were observed in 12%, 4%, and 0.6% of cases, respectively. Nationality influenced the prevalence of multiple MEFs, whereas laterality and study type did not. The pooled mean diameter of the MEF was 2 mm (95% CI: 1.55-3.14).
Conclusions:
The MEF is a common but highly variable anatomical structure. Awareness of its prevalence and morphology is essential for neurosurgical planning, emphasizing the importance of high-resolution preoperative imaging to minimize vascular complications during posterior cranial fossa approaches.
Insights
The mastoid emissary foramen (MEF) is a common anatomical structure, found in 74% of skulls, but its size and number vary significantly. Understanding MEF anatomy is crucial for preventing bleeding during neurosurgery.
Area of Science:
- Anatomy
- Neurosurgery
- Radiology
Background:
- The mastoid emissary foramen (MEF) transmits the mastoid emissary vein and is significant in posterior cranial fossa surgeries.
- Vascular complications can arise from MEF injury due to its variable nature.
- Existing data on MEF prevalence and morphology are inconsistent.
Purpose of the Study:
- To systematically review and meta-analyze the prevalence and morphometry of the mastoid emissary foramen.
- To provide updated, pooled estimates for MEF characteristics.
Main Methods:
- A systematic review and meta-analysis adhering to PRISMA 2020 and Evidence-based Anatomy guidelines.
- Inclusion of osteological and imaging studies reporting MEF prevalence or morphometry.
- Calculation of pooled prevalence and morphometric estimates using random-effects models.
Main Results:
- Twenty-one studies with 8,689 skull sides were analyzed.
- The pooled prevalence of the MEF was 74%, with 26% showing absence.
- A single MEF was most common (53%), multiple MEFs occurred in 16%, and the mean diameter was 2 mm.
Conclusions:
- The mastoid emissary foramen is a prevalent yet highly variable anatomical feature.
- Knowledge of MEF prevalence and morphology is vital for neurosurgical planning.
- High-resolution preoperative imaging is recommended to mitigate vascular risks in posterior cranial fossa approaches.
