Enhanced catheter propagation with hypercapnia during superselective cerebral catherisation.

During arterial catherisation of a cerebral arteriovenous malformation it may be difficult or impossible to access the nidus of the malformation through its small, tortuous feeding vessels due to microcatheter impaction. Carbon dioxide, a most potent cerebral vasodilator, was temporarily added to the inspired gases of two anaesthetised patients undergoing superselective embolisation of an arteriovenous malformation, when the microcatheter had been impacted for a considerable time. Successful propagation of the microcatheter into the malformation was achieved in both patients after a relatively short period of hypercapnia.