Problems with post-clipping aneurysmal rests.

Abstract

The postclipping aneurysmal rest is a uncommon but sometimes dangerous event, that is generally underestimated. We distinguish the aneurysmal rest on the basis of its morphology in: 1) partial neck, 2) whole neck, 3) partial neck + partial sac, 4) whole neck + partial sac; on the basis of the relationship with the clip in: 1) proximal, 2) distal, 3) proximal + distal; on the basis of its size in: 1) small (< 2 mm), 2) medium (2-4 mm), 3) large (> 4 mm). From the surgical point of view the aneurysmal rests in our opinion can be classified as unavoidable, avoidable and intentional. Then we analyze the literature data in regard to the possible evolution and the risk of the rest and emphasize the importance of intraoperative angiography which has shown itself to be useful in avoiding aneurysmal rests. There is no consensus of opinion with regard to the type of treatment of the aneurysmal rest. In our opinion the factors which must be considered when deciding on the surgical treatment of a rest are: the age of the patient, mode of presentation of the previous aneurysm, the expertise of the surgeon and the approaches and the techniques used in the first operation, clinical presentation of the rest and its evolution, the surgeon's experience and the possibility of endovascular therapy. Finally we analyze some of the technical aspects of re-operation in relation to the anatomical relationship among the parent artery, the rest and the old clip.