小児の涙道閉塞診療におけるCTの検討

Lacrimal duct obstruction in children: assessment of computed tomography（CT）

要約　目的：小児の涙道閉塞に対して術前に施行した涙道造影CTの検討。

対象と方法：2020年4月〜2023年2月に九州大学病院で涙道内視鏡下で涙管チューブ挿入術を試みた小児のうち術前にCTを施行した27例（32側）を対象に，解剖学的構造，涙道造影の可否，骨性異常の有無について検討した。

結果：平均年齢（±標準偏差）は3.8±2.9歳，男児が14例（51.9％）であった。チューブ挿入術の成功率は93.8％（30/32側）であった。CTより軸位断での患側の鼻涙管の最小内腔径平均は3.0×4.1mm，矢状断での鼻涙管長平均は21.6±3.3mmであった。造影方法は点眼法が19例，注入法が4例であった。患側で造影できたのは点眼法，注入法ともに約50％と同程度だった。涙道閉塞の原因は，先天性鼻涙管閉塞24側（75.0％），後天性4側（12.5％），骨性異常3側（9.4％），鼻性1側（3.1％）であった。

結論：CTは術前に鼻性や骨性異常などの解剖学的情報を得られる有用な評価方法であるが，被曝のリスクを考慮し，個々の症例で慎重に必要性を検討する必要がある。

Abstract　Purpose：To assess the utility of preoperative lacrimal duct contrast computed tomography（CT）scan for lacrimal duct obstruction in children.

Methods：Twenty-seven children（32 sides）who underwent attempted silicone tube intubation and preoperative CT were included in this study. Clinical data including anatomical structure, visibility of contrast agent in the lacrimal duct, and bony stenosis were retrospectively obtained.

Results：The mean age（±standard deviation）was 3.8±2.9 years and fourteen patients（51.9％）were boys. Lacrimal intubation was successful in 93.8％（30 sides）of patients. The mean minimum inner diameter of the nasolacrimal duct on the affected side was 3.0×4.1 mm. The mean duct length in sagittal section was 21.6±3.3 mm. Contrast agent was confirmed in 19 cases and four cases administered by eye-drop and syringing, respectively. In each contrast method, the contrast could be seen on the affected side in about 50％ of cases, regardless of contrast method. The causes of lacrimal duct obstruction were congenital nasolacrimal duct obstruction on 24 sides（75.0％）, acquired nasolacrimal duct obstruction on four sides（12.5％）, bony stenosis on three sides（9.4％）, and nasal obstruction on one side（3.1％）.

Conclusion：CT is a useful preoperative evaluation method that provides anatomical information such as bony stenosis. However, the need for CT should be carefully considered in each case, taking into account the risk of radiation exposure.