POSTERIOR COMMUNICATING ARTERY SECTION DURING SURGERY FOR BASILAR TIPANEURYSM

Although dividing the posterior communicating artery (PComA) during su rgery has been criticized for increasing the risk of ischaemia, this p rocedure increases working space improving visibility and the ability to manipulate during treatment of basilar tip aneurysms via the pterio nal approach. We divided a hypoplastic PComA in 4 of our cases of basi lar tip aneurysm. This was necessary because either (1) the length of the PComA and intracranial internal carotid artery (ICA) limited media l retraction of the ICA and access to the basilar bifurcation region, or (2) the PComA and its perforators ran just in front of the aneurysm , interfering with its exposure. We were able to clip the aneurysm nec k in all four patients, three of whom had complications including temp orary impairment of consciousness, ocular movement disorders and alter ed sensation in the extremities. Patients with complications showed tr ansient hypersomnolence immediately after surgery; computed tomography showed small thalamic infarctions. However, in two of three patients the ischaemic events occurred contralateral to the side of PComA secti on. All patients regained consciousness within a week and were dischar ged with mild ocular movement palsies. In our cases except one with is chaemic complications, thalamic infarction probably resulted from thal amo-perforating artery injury when the aneurysm neck was clipped, rath er than tuberothalamic artery injury due to section of the PComA. Taki ng previous reports and our results into consideration, we believe tha t division of a hypoplastic PComA is a safe procedure in particular ca ses when the grade of subarachnoid haemorrhage is not poor and there a re no cerebrovascular risk factors, although we realize it is desirabl e to preserve normal blood flow.