title: Aneurysm growth and de novo aneurysms during aneurysm surveillance.
abstract: OBJECTIVE Many low-risk unruptured intracranial aneurysms (UIAs) are followed for growth with surveillance imaging. Growth of UIAs likely increases the risk of rupture. The incidence and risk factors of UIA growth or de novo aneurysm formation require further research. The authors retrospectively identify risk factors and annual risk for UIA growth or de novo aneurysm formation in an aneurysm surveillance protocol. METHODS Over an 11.5-year period, the authors recommended surveillance imaging to 192 patients with 234 UIAs. The incidence of UIA growth and de novo aneurysm formation was assessed. With logistic regression, risk factors for UIA growth or de novo aneurysm formation and patient compliance with the surveillance protocol was assessed. RESULTS During 621 patient-years of follow-up, the incidence of aneurysm growth or de novo aneurysm formation was 5.0%/patient-year. At the 6-month examination, 5.2% of patients had aneurysm growth and 4.3% of aneurysms had grown. Four de novo aneurysms formed (0.64%/patient-year). Over 793 aneurysm-years of follow-up, the annual risk of aneurysm growth was 3.7%. Only initial aneurysm size predicted aneurysm growth (UIA < 5 mm = 1.6% vs UIA ≥ 5 mm = 8.7%, p = 0.002). Patients with growing UIAs were more likely to also have de novo aneurysms (p = 0.01). Patient compliance with this protocol was 65%, with younger age predictive of better compliance (p = 0.01). CONCLUSIONS Observation of low-risk UIAs with surveillance imaging can be implemented safely with good adherence. Aneurysm size is the only predictor of future growth. More frequent (semiannual) surveillance imaging for newly diagnosed UIAs and UIAs ≥ 5 mm is warranted.
authors.affiliation: Department of Neurosurgery.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Serrone
authors.affiliation: Department of Neurosurgery.
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Tackla
authors.affiliation: Department of Neurosurgery.
authors.forename: Yair M
authors.initials: YM
authors.lastname: Gozal
authors.affiliation: Department of Surgery, Division of Trauma/Critical Care.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Hanseman
authors.affiliation: Department of Neurosurgery.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Gogela
authors.affiliation: Department of Neurosurgery.
authors.forename: Shawn M
authors.initials: SM
authors.lastname: Vuong
authors.affiliation: Department of Neurosurgery.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Kosty
authors.affiliation: University of Cincinnati College of Medicine; and.
authors.forename: Calen A
authors.initials: CA
authors.lastname: Steiner
authors.affiliation: Department of Neurosurgery.
authors.forename: Bryan M
authors.initials: BM
authors.lastname: Krueger
authors.affiliation: Department of Neurosurgery.
authors.forename: Aaron W
authors.initials: AW
authors.lastname: Grossman
authors.affiliation: Department of Neurosurgery.|Department of Radiology, University of Cincinnati College of Medicine.|Comprehensive Stroke Center at the University of Cincinnati Neuroscience Institute; and.|Mayfield Clinic, Cincinnati, Ohio.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Ringer
mesh_terms: D002533:Cerebral Angiography; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
keywords: CTA = CT angiography; DSA = digital subtraction angiography; MRA = MR angiography; SAH = subarachnoid hemorrhage; UIA = unruptured intracranial aneurysm; aneurysm; de novo; growth; subarachnoid hemorrhage; surveillance; vascular disorders