Surgical removal of an arteriovenous malformation in the anterior perforated substance in a pregnant woman

BACKGROUND: A tailor-made treatment is often required in arteriovenous malformations (AVMs) depending on the individual situation. In most cases, treatment strategy is usually determined according to the patient's Spetzler–Martin grade. However, in the present case, we were not able to treat the patient following the usual guidelines because of neurological symptoms and pregnancy. CASE DESCRIPTION: We describe a rare case of a 31-year-old woman in the 15(th) week of gestation who presented with an AVM in the anterior perforated substance (APS). She suffered a sudden coma and hemiplegia. A computed tomographic scan showed an enhanced mass and a huge hematoma in the basal ganglia and temporal lobe. The hematoma was successfully evacuated in an endoscopic procedure. Angiography showed that a 25-mm nidus in the APS was fed by the anterior choroidal arteries (AChAs) and the lenticulostriate arteries (LSAs). Therefore, we attempted to remove the nidus because the patient became alert with mild aphasia and hemiparesis 10 days after hemorrhage. The feeding arteries were cut under motor evoked potential (MEP) monitoring, and the nidus was totally resected leaving two of four AChAs and a single artery with several LSAs. The postoperative course was uneventful, and she gave birth to a healthy baby by caesarian delivery 122 days after the hemorrhage with only minor sequelae. CONCLUSIONS: Surgical strategy with a device-administered anesthesia are suitable for removing large AVMs even in pregnant women and for the successful outcome of their pregnancies. Even after recovering from a coma and hemiplegia, MEP monitoring is effective for removing large AVMs even when located in the APS.