Surgical treatment of pial cerebellar arteriovenous fistulas with aneurysm of the main feeder artery

BACKGROUND: Intracranial pial arteriovenous fistulas (pAVFs) are rare vascular lesions only recently considered distinct from arteriovenous malformations. Conservative management was associated with a high mortality rate. The abnormality of the lesion arises from its high-flow nature. The authors present a case of a cerebellar pAVF associated with aneurysms of the main feeding artery that was surgically treated. CASE DESCRIPTION: A 54-year-old woman was referred to us after an attack of severe headache and vomiting. Computerized tomography scan visualized a hematoma of the fourth ventricle. Digital subtraction angiography (DSA) revealed a cerebellar pAVF mainly fed by the right posteroinferior cerebellar artery (PICA) and with drainage into one of the superior cerebellar veins. The PICA presented a saccular aneurysm on its fourth segment and a fusiform dilatation on its third segment. The patient underwent surgical operation via a midline suboccipital craniotomy. The fusiform dilatation was wrapped and the saccular aneurysm was clipped. The most fistulous connections were closed. The draining vein at the level of torcular herophili was closed by application of a clip. Control DSA demonstrated exclusion of both the aneurysms and the fistula from the circulation. At 1-year follow-up, the patient was neurologically intact. CONCLUSIONS: The association of a cerebellar pAVF and an aneurysm is rare. Surgical treatment of multiple-channel arteriovenous fistulas by closure of venous varix should guarantee the exclusion from the circulation and avoid recruitment of new arterial connections and recurrence. Attention must be paid to normal venous channels draining into the varix.