Efficacy of Adenosine Triphosphate-induced Transient Cardiac Arrest for Deflation of Cerebral Aneurysms during Clipping Surgery

Clipping surgery for cerebral aneurysms occasionally requires transient deflation of the aneurysm to prevent its rupture and to avoid injury to the surrounding tissue structure. Temporary occlusion of the parent artery is an effective method to reduce the pressure of the aneurysm. However, with large aneurysms, blocking the parent artery may not be a suitable alternative. In addition, temporary occlusion may be prohibited by the existence of atherosclerotic changes or perforating branches in the parent artery. Transient cardiac arrest (TCA) induced by adenosine triphosphate (ATP) is an effective alternative in such cases. This method leads to a temporary softening of the aneurysm. Adenosine is a purine nucleoside that suppresses atrioventricular conduction. A bolus dose of ATP causes momentary cardiac arrest. Here, we describe the advantages of inducing TCA to the clipping process.<br>  Eighty-seven consecutive patients with aneurysms (ruptured aneurysms : 39, unruptured aneurysms : 48) were surgically treated between 2012 and 2013. Of these, seven patients with anterior circulation aneurysms underwent TCA-inclusive surgery. Among them, five had ruptured aneurysms and two had an unruptured aneurysm. Bolus intravenous injection of ATP (10-120 mg) was administered at a dose deemed fit by the anesthesiologist to satisfy the arrest duration requested by the surgeon. Microsurgery was then performed during the short period of cardiac arrest.<br>  We observed 3-40 seconds of cardiac arrest and noted remarkable softening or collapse of the aneurysms in all cases. In every case, the aneurysms were successfully obliterated without rupture, and the heartbeat recovered spontaneously without any additional intervention. Complications associated with TCA were not observed in any of these patients.<br>  TCA facilitated safe and quick dissection of the aneurysm and clip application during the clipping operation. This approach is useful when temporary occlusion of the parent artery is difficult. In addition, TCA provides an added advantage of no parent artery injury, which is often associated with its temporary occlusion.<br>  ATP-induced TCA is a quite useful and safe approach when temporary occlusion of the parent artery is not feasible, although the former requires close monitoring by an experienced anesthesiologist.