妊娠を契機に発症したシャント機能不全の1例

Ventriculoperitoneal Shunt Malfunction due to Pregnancy

Ⅰ．は じ め に

　1960年代以降，シリコンチューブの開発により水頭症に対する脳室腹腔短絡術（以下，VPシャント術）は脳神経外科領域において日常的に行われるようになった．また，これに伴いシャント機能不全を経験することも稀ではなく，小児においてはシャント術後1年以内に約3割がシャント機能不全を生じるとの報告もある^16,18)．その原因としてはチューブの機械的な閉塞，システムの故障および感染が大部分を占める⁹⁾．

　今回，われわれはVPシャント術を受けた患者が後に妊娠を契機にシャント機能不全を発症し，出産後にシャント機能不全が治癒した1例を経験したので文献的考察を加えて報告する．

A 27-year-old female was admitted to our department due to gait disturbance and disorientation. Computed tomography (CT) scan revealed symmetrical ventricular dilatation. She was pregnant at 25 weeks of gestation. At the age of 16 years,she had received a ventriculo-peritoneal (VP) shunt for hydrocephalus,induced by a cerebellar medulloblastoma. Neurological examination at the current admission showed that she was disoriented with ataxic gait and convergence nystagmus. Analysis of the cerebrospinal fluid showed normal cell composition. Magnetic resonance images (MRI) and Thalium-single photon emission tomography (Tl-SPECT) revealed no recurrence of the tumor. The radio-isotope shunt flow study showed there was no obstruction of the shunt tube or retardation of intraabdominal diffusion.

　The patient was diagnosed as having shunt malfunction without obstruction of the shunt tube. We performed pumping of a flushing device for the shunt system. As a result her symptom was gradually improved. The follow-up MRI,20 days after the using,showed complete disappearance of hydrocephalus. She was discharged from our hospital 1 month later. She continued pumping of the flushing device by herself at home. Three months later,she delivered a healthy infant by vaginal labor. She has not need to do pumping after that. And MRI showed no sign of hydrocephalus.