Study on superficial temporal artery guided interfascial pterional approach for the protection of facial nerve branches

Objective To investigate the protection of facial nerve branches during craniotomy through interfascial pterional approach by studying the microsurgical anatomy in cadaver head specimens. Methods Temporal branch of facial nerve and branches of superficial temporal artery (STA) of 15 cadaver heads (30 sides) were studied by microsurgical anatomy to investigate the relationship between STA, zygomatic arch and temporal branch of facial nerve, and the distribution of facial nerve branches in temporal fascial space. Verified the feasibility and safety of frontal-temporal branch of STA as an anatomic marker for the interfascial pterional approach to protect the temporal branch of facial nerve and its branches. Fifty clinically selected craniotomy cases were operated through interfascial pterional approach with frontal-temporal branch of STA for anatomic marker. Observed the post-operative injury of temporal branch of facial nerve. Results All of the temporal branch of facial nerve and its branches in 30 sides were located in the temporal muscle interfascial fatty layer (the first and second layer of fat pad) between the frontal-temporal branch of STA and the superior margin of zygomatic arch. Temporal branch of facial nerve possessed (4.00 ± 1.80) branches. The distance between superior margin of frontal branch of facial nerve and inferior margin of the frontal-temporal branch of STA was (4.70 ± 2.60) mm. All of the main temporal branches of facial nerve were accompanied with the main branch of STA. In 8 sides, temporal branches of facial nerve were located at the front of STA branch not far than 5 mm, and in 22 sides, they were located at the front of STA branch 5-10 mm. Frontal-temporal branch of STA was single in 29 sides, and it presented with double trunks in one side. STA and its frontal-temporal branch could be exposed and the frontal-temporal branch was used as anatomic markers for interfascial pterional approach in 50 craniotomy cases, no injury of facial nerve branches were seen after operation. Conclusion STA and its branches can be used as anatomic markers to incise the interfascial space in time in operation through interfascial pterional approach. This method can protect temporal branch of facial nerve and its branches, enhance the operation efficiency and reduce complication. It can also protect STA and its branches, reduce surgical injury, and protect regional blood circulation.