術前予想より深部に存在した鉛筆による眼窩内異物の手術経験

A piece of pencil as intraorbital foreign body located deeper than presurgical estimation

要約　目的：術前予想より深部に存在した色鉛筆による眼窩内異物の手術経験の報告。症例：2歳男児が金色の色鉛筆で受傷した。術前のコンピュータ断層撮影では眼窩内の内直筋近傍に異物像を認めた。全身麻酔下で経結膜切開にて手術を行った。目視で確認できないため，術中透視を行うと術前予想より深部にあり眼窩隔膜を破り眼窩脂肪織内に入り込んでいた。異物は水分を含み脆弱化，細分化しており摘出時，脂肪織と一緒にさらに深部に移動したが透視下ですべて摘出した。眼瞼腫脹と結膜浮腫が長期強度にみられた。結論：異物が眼窩脂肪織に入り込むと，術中透視によって位置を把握しないと術前の予想より深部に存在する場合があるので注意が必要である。

Abstract.　Purpose：To report a case with an intraorbital foreign body located deeper than presurgical estimation. Case：A 2-year-old boy presented with an intraorbital foreign body. He had been injured in the right eye the day before while playing with a gold-colored pencil. Computed tomography showed a foreign body located near the medial rectus muscle. Surgery was performed via conjunctival approach under general anesthesia. The foreign body could not be identified immediately. X-ray showed the broken piece of pencil located deeper than presurgical estimation,as it was buried in the orbital fat and moved deeper by surgical manipulation. Conclusion：This case illustrates that adjunct intraoperative use of X-ray may be of value for intraorbital foreign body,as it may be located deeper than previous estimation.