Midterm outcome of partially thrombosed intracranial aneurysms treated with guglielmi detachable coils

Abstract

We evaluated the results of Guglielmi detachable coil (GDC) treatment in partially thrombosed aneurysms and determined if there is high rate of recanalisation on follow-up. Among 149 treated aneurysms in 141 patients, 25 CT- or MR-confirmed partially thrombosed aneurysms were selected for evaluation. The features of thrombosed aneurysms and percentage of occlusion were analysed on initial angiograms. Follow-up angiograms, which were available in 18 cases, were evaluated for aneurysm lumen recanalisation. The recanalisation rate was compared with that of non-thrombosed aneurysms treated with GDCs. Locations of aneurysms were as follows: cavernous carotid ten; ophthalmic four; p-com. two; MCA one; A-com. one; basilar tip four; midbasilar two; PICA one. The size of the aneurysm lumen ranged from 5 to 30 mm (mean 16.8 mm) on angiograms, but on cross sectional images the size of aneurysms ranged from 13 to 70 mm (mean 24.6 mm). The extent of aneurysmal thrombosis ranged from 10 to 90 per cent (mean 46.4 per cent). On initial GDC treatment, total to subtotal occlusion was achieved in 18 cases out of 25 (72%). Of the 18 follow-up angiograms, 14 cases (77.8%) showed recanalisation ranging from 10 to 60 per cent of aneurysm size. Luminal recanalisation was due to migration (10 of 14) or compaction (4 of 14) of coil masses. In two cases, symptoms recurred in association with aneurysm recanalisation, but in no instance was haemorrhage noted. Attempts for retreatment were made in ten cases with success in six. In comparison, 14 (15.9%) out of 88 nonthrombosed cases revealed recanalisation on follow-up angiography. Midterm follow-up angiograms in partially thrombosed aneurysms treated with GDC revealed a fivefold higher rate of recanalisation than in non-thrombosed cases. Close follow-up is necessary in patients with thrombosed aneurysms treated with GDCs.

Figure 1

Non-recanalisation. Pre-contrast CT (A) reveals high density mass with rim calcification in the left suprasellar area. The denser area (arrow) represents the lumen and the surrounding low density area represents a thrombus. Left carotid angiogram (B) shows an aneurysm arising from the ophthalmic artery origin. Post-procedure angiogram (C) shows more than 95% occlusion of lumen with GDCs. On seven month follow-up angiogram (D), there is no change in coil position or shape.

Figure 2

Migration of coil mesh. Tl-weighted MR (A) shows an elongated shape aneurysm arising from the basilar artery with internal multilayer high signal (arrow). Left vertebral angiogram (B) demonstrates a 7 mm aneurysm arising from the superior cerebellar artery origin. The superior cerebellar artery is not visible. Immediate post-procedure angiogram (C) shows complete occlusion of the aneurysm. On 7 month follow-up angiogram (D), coil mesh migrated laterally without significant change in coil mesh shape and recanalised lumen.

Figure 3

Compaction of coil mesh. Contrast enhanced CT (A) shows an enhancing aneurysm in the left posterior communicating artery origin area. Note focal non-enhancing portion representing a thrombus. Left internal carotid angiogram (B) shows an aneurysm at the same location. The aneurysm was occluded with GDCs and achieved 95% occlusion (C). Eight month follow-up angiogram (D) shows coil mesh compaction without migration.

Figure 4

Predominant migration of coil mesh. T1-weighted MR (A) with contrast enhancement shows a partially thrombosed aneurysm in the interpeduncular fossa. The thrombus shows low signal with marginal high signal and residual lumen shows enhancement. Lateral angiogram of the vertebral artery (B) reveals an aneurysm arising from the basilar tip. Immediate post-procedure angiogram (C) shows 95% occlusion of the aneurysm. Fifteen months follow-up angiogram (D) shows migration of coil mesh toward the fundus and lumen recanalisation. In addition the coil mesh shows compaction. This patient was treated again. On 4-year follow-up angiogram (E), coils migrated to the dome and the lumen recanalised. Final angiogram (F) after the repacking procedure shows more than 95% occlusion of the lumen.