脳室内腫瘍に合併する水頭症の治療

Treatment for Hydrocephalus Caused by Intraventricular Tumors

Point

・脳室内腫瘍による水頭症は髄液循環路の閉塞のほか，髄液の吸収障害や産生過多によって生じ，その原因を正しく判断することが重要である．

・腫瘍の組織型はさまざまであり化学療法や放射線治療に感受性のよい腫瘍もあるため，水頭症治療と同時に生検を行うメリットは大きい．

・頭蓋内圧が高い症例への脳室ドレナージや脳室腹腔シャントは，上行性ヘルニアを生じる危険があり注意を要する．

　Intraventricular tumors often cause hydrocephalus because their location in the ventricles affect cerebrospinal fluid circulation. Even small tumors can lead to acute hydrocephalus when they block the cerebrospinal fluid flow. They may also be found as large tumors occurring in large spaces, such as in lateral ventricles.

　Since various histological tumors occur in ventricles, it is important to consider the treatment strategy according to the expected histological type before treating hydrocephalus in the early stage. In addition, it is beneficial to predict and evaluate the site and size of the tumor, the cause of hydrocephalus, and the effect of postoperative chemotherapy and radiation therapy. Some tumors are sensitive to chemotherapy and radiation therapy, so there is an advantage in performing a biopsy at the same time as hydrocephalus treatment.

　Ventricular drainage and ventricular peritoneal shunts for patients with high intracranial pressure are at risk of developing ascending hernias, so we should be careful with the procedure.