ABSTRACT
Consider image guidance in cases that are re-do or extended approaches or have difficult sellar anatomy when performing endoscopic or microscopic-assisted transsphenoidal surgery. Intraoperative swelling can occur throughout surgery: at the time of dural opening, clot evacuation or closure. The location of the nidus determines the ‘eloquence’ of the arteriovenous malformation and predicts the patient’s potential post-operative neurological deficits. Knowing the location of the surface draining veins is the key to intraoperative localization of the nidus. The discussion begins in the preoperative period by confirming the diagnosis, obtaining informed consent and marking the patient. The patient is placed in the supine position with head elevated and rotated away from the operative side. Direct intraoperative ventricular puncture by aspiration of cerebrospinal fluid should be considered, especially in the presence of ventriculomegaly and a swollen brain precluding access to the basal cisterns.
