[Analysis of internal carotid-posterior communicating artery aneurysms with difficulty in clipping: with special...

Although internal carotid-posterior communicating artery (ICPC) aneurysms seem to be one of the easiest to be operated on, some are known difficult to handle and could not be successfully clipped even with all sorts of preparations. It is, therefore, essential to analyze ICPC aneurysms with difficulty in clipping. Out of 106 cases with ICPC aneurysms admitted to Kyoto University Hospital since May 1977, 83 cases have been registered in this study to the exclusion of either non-operated cases or giant aneurysm cases. Cases with difficulty in clipping procedure are selected and classified depending on its causes, which were judged from operation records as well as operative photographs. Angiograms have been checked to discuss whether possible causes of difficulty in clipping could have been suspected preoperatively. Radiometry were also performed in the following items; distance between the anterior clinoid process (ACP) and proximal side of the aneurysmal neck (W) in AP view, distance of proximal side of the neck from ACP (D) and its height (H) from the baseline between the ACP and posterior clinoid process in lateral view. Causes of difficulty in clipping procedure can be grouped as follows: a) ventrally directed dome of the aneurysm (9 cases), b) incision of the plica petroclinoidea anterior (PPA) or removal of the anterior clinoid process (ACP) to identify proximal side of the neck (7 cases: b group), c) saucer-shaped dome with no apparent neck, d) branches of the internal carotid artery from dome.(ABSTRACT TRUNCATED AT 250 WORDS)