Titanium aneurysm clips: Mechanical characteristics and clinical trial

Abstract

Titanium clip is well documented to reduce the artifact observed in computed tomography (CT) or magnetic resonance (MR) imaging and improve the quality of these images. There are, however, some demerits based on metallic characteristics including large spring portions, lack of long and fenestration clips, and difficulties to produce. We examined the mechanical characteristics of Sugita titanium aneurysm clips (product of 6 aluminium-4 vanadium-titanium) and investigate the safety in clinical use and the imaging quality compared with those of cobalt (Co) alloy clips. On mechanical test, Sugita titanium clips showed no significant difference in closing force compared with the conventional Co alloy clips. The closing force reduced about 10% after 100 times repeated opening in titanium clips in contrast with no remarkable changes in Co alloy clips. Sixty-four patients with ruptured or unruptured cerebral aneurysms (total number of 71 aneurysms) were treated with Sugita titanium clips through the microsurgical technique. None of the unfavorable outcome occurred in related to the titanium clips. Neither clip dislocation nor deformation was experienced in this series during the follow- up period. The clip artifacts seen in CT and MR image were markedly reduced, however, MR angiography had less quality to resolve anatomical structures due to an existence of vessel gap. These results indicate that in spite of some disadvantages, Sugita titanium clips allow safe and beneficial use routinely in aneurysm surgery insofar as the complete clipping is obtained.