Japanese to English Science Medical (general) surgery

脳外科医が前頭開頭し嚢胞摘出後，耳鼻科医が左前頭洞嚢胞を摘出した。

This is from a case report in which a patient had a maxillary sinus mucocele (前頭洞嚢胞) surgically removed.

I don't understand the division of labour here. There is only one mucocele and throughout the text it is specified as a left maxillary sinus mucocele (左前頭洞嚢胞). So when the brain surgeon performs 嚢胞摘出, what is he doing?

The mucocele is pressing on the frontal lobe so perhaps 摘出 here simply means separation/extrication rather than resection (the brain tissue itself is not cut into at any point)?; or perhaps the brain surgeon resects the portion pressing on the brain and the otolaryngologist does the rest?

Any ideas would be much appreciated.