Eung Koo Yeon1, Young Dae Cho2, Dong Hyun Yoo2, Su Hwan Lee3, Hyun-Seung Kang4, Jeong Eun Kim4, Won-Sang Cho4, Hyun Ho Choi5, Moon Hee Han6. 1. 1Department of Radiology, KyungHee University Medical Center, KyungHee University College of Medicine. 2. 2Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul. 3. 3Department of Neurosurgery, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Ilsan. 4. 4Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine. 5. 5Department of Neurosurgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine; and. 6. 6Department of Radiology, Veterans Health Service Medical Center, Seoul, Korea.
Abstract
OBJECTIVE: The authors conducted a study to ascertain the long-term durability of coiled aneurysms completely occluded at 36 months' follow-up given the potential for delayed recanalization. METHODS: In this retrospective review, the authors examined 299 patients with 339 aneurysms, all shown to be completely occluded at 36 months on follow-up images obtained between 2011 and 2013. Medical records and radiological data acquired during the extended monitoring period (mean 74.3 ± 22.5 months) were retrieved, and the authors analyzed the incidence of (including mean annual risk) and risk factors for delayed recanalization. RESULTS: A total of 5 coiled aneurysms (1.5%) occluded completely at 36 months showed recanalization (0.46% per aneurysm-year) during the long-term surveillance period (1081.9 aneurysm-years), 2 surfacing within 60 months and 3 developing thereafter. Four showed minor recanalization, with only one instance of major recanalization. The latter involved the posterior communicating artery as an apparent de novo lesion, arising at the neck of a firmly coiled sac, and was unrelated to coil compaction or growth. Additional embolization was undertaken. In a multivariate analysis, a second embolization for a recurrent aneurysm (HR = 22.088, p = 0.003) independently correlated with delayed recanalization. CONCLUSIONS: Almost all coiled aneurysms (98.5%) showing complete occlusion at 36 months postembolization proved to be stable during extended observation. However, recurrent aneurysms were predisposed to delayed recanalization. Given the low probability yet seriousness of delayed recanalization and the possibility of de novo aneurysm formation, careful monitoring may be still considered in this setting but at less frequent intervals beyond 36 months.
OBJECTIVE: The authors conducted a study to ascertain the long-term durability of coiled aneurysms completely occluded at 36 months' follow-up given the potential for delayed recanalization. METHODS: In this retrospective review, the authors examined 299 patients with 339 aneurysms, all shown to be completely occluded at 36 months on follow-up images obtained between 2011 and 2013. Medical records and radiological data acquired during the extended monitoring period (mean 74.3 ± 22.5 months) were retrieved, and the authors analyzed the incidence of (including mean annual risk) and risk factors for delayed recanalization. RESULTS: A total of 5 coiled aneurysms (1.5%) occluded completely at 36 months showed recanalization (0.46% per aneurysm-year) during the long-term surveillance period (1081.9 aneurysm-years), 2 surfacing within 60 months and 3 developing thereafter. Four showed minor recanalization, with only one instance of major recanalization. The latter involved the posterior communicating artery as an apparent de novo lesion, arising at the neck of a firmly coiled sac, and was unrelated to coil compaction or growth. Additional embolization was undertaken. In a multivariate analysis, a second embolization for a recurrent aneurysm (HR = 22.088, p = 0.003) independently correlated with delayed recanalization. CONCLUSIONS: Almost all coiled aneurysms (98.5%) showing complete occlusion at 36 months postembolization proved to be stable during extended observation. However, recurrent aneurysms were predisposed to delayed recanalization. Given the low probability yet seriousness of delayed recanalization and the possibility of de novo aneurysm formation, careful monitoring may be still considered in this setting but at less frequent intervals beyond 36 months.
Entities:
Keywords:
DNIA = de novo intracranial aneurysm; SAH = subarachnoid hemorrhage; TOF = time-of-flight; aneurysm; coiling; follow-up; recanalization; vascular disorders