ピオクタニンブルー®を腫瘍囊胞内に注入して全摘出した転移性脳腫瘍の1例

Pyoktanin Blue Injection for Resection of Cystic Brain Tumor: A Case Report

Ⅰ．はじめに

　囊胞性病変の摘出の際に，囊胞壁を損傷すると，正常脳との境界がわかりにくくなり，全摘出が困難となることがある．全摘出を確実にする目的でこれまでさまざまな手法が開発されてきた．その代表が，ナビゲーションシステムや5-aminolevulinic acid（5-ALA），術中MRI，術中超音波などである^5,10,11)．しかし，いずれも施行するためには設備が必要であり，あらゆる施設で行えるとは限らない．

　他科ではあるが囊胞性病変に対して囊胞内に色素注入を行うことが摘出に有用であるという報告がある^4,9)．囊胞内壁面を染色して視認性をよくする手法である．今回，それらの報告を基に，囊胞性転移性脳腫瘍に対する開頭摘出術の際にピオクタニンブルー^®（和光純薬工業，大阪）を囊胞内注入し，囊胞壁を損傷せずに全摘出した．囊胞内へのピオクタニンブルー^®注入は，囊胞性脳腫瘍全摘出の補助手段として有用と思われたためtechnical noteとして報告する．

　Pyoktanin blue is an agent that is often used during STA-MCA anastomosis. In this report, we inject it into a cystic tumor for complete resection, and we report its usefulness.

　The patient was a 57-year-old female. She suffered from progressive cerebellar ataxia. CT and MR showed a cystic metastatic tumor at the right cerebellar hemisphere, 40mm in diameter. Craniotomy was performed, 5cm in diameter, using the right suboccipital approach. After peeling off the tumor from the surface layer of the brain, we injected diluted pyoktanin blue into the tumor to dye the inside wall. After that, the tumor was peeled off completely without exposing the dyed inside wall.

　We sometimes find it difficult to distinguish tumor from brain if there is tearing of the tumor wall. Tearing of the tumor can be prevented by injecting pyoktanin blue into it, and making the inside wall visible. Using this procedure, we think a tumor can be resected without residual tumor or damage to the brain. Although we have used this method only a few times, we think it is an easy and useful technique to inject pyoktanin blue into a cystic tumor during its resection.