Clinical and Imaging Follow-Up of Patients with Coiled Basilar Tip Aneurysms Up to 20 Years

Abstract

Background and purpose: Long-term follow-up data of coiled basilar tip aneurysms are scarce, and little is known about the risk of late aneurysm-related adverse events. We followed a cohort of 154 patients with basilar tip aneurysms coiled between 1995 and 2006.

Materials and methods: Imaging and clinical data were retrospectively reviewed. The incidence and timing of retreatment, rebleeds, and progressive mass effect by continuous aneurysm growth were recorded. Risk factors for retreatment were assessed.

Results: Clinical follow-up of 144 of 154 patients who survived the admission period was a mean of 9.8 years (median, 10.2; range, 0.3-20.1 years). During this period, 37 basilar tip aneurysms (26%) were additionally coiled (annual incidence rate, 2.6%; 95% CI, 1.8%-3.6%). Aneurysm size of >15 mm was the most important independent predictor for retreatment (OR, 8.7; 95% CI, 3.4-22.5). The first additional coiling was performed in the first year of follow-up in 17 of 37 patients (46%) and in 20 patients (54%) at a later time up to 17.2 years. Nine rebleeds occurred in 9 of 106 patients who initially presented with SAH after a median follow-up of 8.3 years (range, 0.3-16.6 years). The annual incidence rate was 0.7% (95% CI, 0.4%-1.5%). Eight patients died of aneurysm-related adverse events: 3 of rebleed and 5 of progressive mass effect.

Conclusions: Retreatment of coiled basilar tip aneurysms was frequently needed during follow-up, also at long intervals. Most late mortality was from progressive mass effect, not from rebleeds. Life-long MRA follow-up at yearly intervals is recommended.

Fig 1.

Follow-up scheme of 154 patients with a basilar tip aneurysm.

Fig 2.

A 41-year-old man with a coiled ruptured basilar tip aneurysm in 1997 and a rebleed 15 years later. A, Angiography in 2006, 9 years after coiling in 1997, shows an adequately occluded basilar tip aneurysm. B, CT in 2012 demonstrates a rebleed from the basilar tip aneurysm. C, Angiography reveals regrowth of the aneurysm (arrow). D, After additional coiling, the aneurysm is completely occluded (arrow).

Fig 3.

Timing of first retreatments in 37 patients with reopened basilar tip aneurysms.

Fig 4.

Timing of retreatments in 15 patients with coiled basilar tip aneurysms and >1 recurrence.

Fig 5.

Serial MR images of a 40-year-old man with a coiled ruptured basilar tip aneurysm in 2003. A, Transversal T2-weighted MR image from December 2003 shows a basilar tip aneurysm 6 months after coiling. B, MR imaging in May 2008 shows enlargement of the aneurysm and compression of the brain stem. C, MR imaging in March 2009 shows further growth, now with edema in the brain stem. D, MR imaging in December 2009 shows a rapid increase in size with enormous compression of the brain stem. The patient died 1 month later.