術後性上顎嚢胞術式の考察

Surgery for Postoperative Cysts of Maxilla

I．はじめに

　術後性上顎嚢胞の画像診断法は従来は普通X線診断法（単純撮影法，断層撮影法）が中心であったが，X線CTの導入によって術前の情報はより詳細となった。今回の報告では後術性上顎嚢胞のX線CT像を検討し，嚢胞に対する術式，ことに下鼻道側壁における鼻内開窓術の適応について報告した。

　この鼻内開窓術の適応となる条件についてはいまだ定説がないが，その最低条件とは，1）嚢胞は単房性であること（画像上も嚢胞内に不完全隔壁をもたない），2）嚢胞の内側壁は下鼻道側壁に接して膨隆していること，が必要であろう。

Postoperative cysts of the maxilla occur as a rather late sequela after 20~30 years from initial Caldwell-Luc operations.

The preoperative CT findings and operative findings in 53 cases were reported.

The cysts were classified according to the size and relation to the lateral wall of the inferior meatus, as the followings.

1) number of cysts (monocystic or multicystic)

2) relationship to the lateral inferior meatal wall (close contact with bulge or not)

3) Incomplete or complete septa in the cysts as evaluated by CT.

Theoretically, a monocyst, in close contact to the lateral inferior meatal wall, and without septa, is indicated for endonasal window operation.

There were 12 cysts out of 53(22.6%), whereas the window operations were performed only in 4 cases (7.5%).

The window operation, is hampered with technical difficulties, such as postoperative later-alization of the lateral meatal wall and rather remote distance (5cm) from the nostril, therefore this operation should not be performed lightly.