Sandra Ferns, on behalf of the LOTUS study group De novo aneurysm formation and growth of untreated aneurysms 5-year MRA follow-up in a large cohort of patients with coiled aneurysms Sandra Ferns, on behalf of the LOTUS study group Depts of Neurosurgery and Radiology, AMC Amsterdam Depts of Neurology and Radiology, UMC Utrecht Dept of Radiology, St. Elisabeth Ziekenhuis, Tilburg Dept of Neurosurgery, Slotervaart Ziekenhuis Amsterdam Depts of Neurosurgery and Radiology, Leiden UMC Depts of Neurosurgery and Radiology, VUMC Amsterdam Depts of Neurology and Radiology, Maastricht UMC All in the Netherlands

Contents Introduction LOTUS study design LOTUS study results Case Conclusion

Background Multiple intracranial aneurysms –40%1 De novo formation and rate of growth unclear2 Growth ↑ rupture risk1,3 Purpose: To determine 5-year incidence de novo aneurysm formation and growth of untreated aneurysms 1; Wiebers DO et al Lancet 2003, 2; Koffijberg H et al J Neurosurg 2008, 3; Juvela S et al J Neurosurg 2000

Methods LOTUS STUDY multicenter prospective >5yrs follow-up study of patients with adequately coiled aneurysms 7 participating Dutch centers with MEC approval

Methods PATIENTS Inclusion criteria: age 18-70 coiling >4.5 years ago GOS 4-5 adequate occlusion after 6 months no contra-indications for MRA at 3 Tesla Selection of patients with fixed follow-up duration of 5 ± 0.5 years

Methods IMAGING EVALUATION 3 Tesla MRI, Philips Medical Systems T2 weighted images MOTSA 3D TOF Standard MIP and VR 3D reconstructions EVALUATION 2 observers Additional aneurysms: compared with initial angiography Unchanged Grown De novo Not comparable

Methods ANALYSES Proportion de novo aneurysm formation and growth Patient- and aneurysm characteristics Patients with versus without additional aneurysms Patients with versus without growth of additional aneurysms

Results 276 patients follow-up 5 ± 0.5 years; 1332 patient years 50/ 276 (18%) had 75 additional aneurysms ♀ RR 2.03, 95%CI 1.03-3.98

Results 58 / 63 known; 92%, 95% CI 85- 99% 13% 58 / 63 known; 92%, 95% CI 85- 99% 2 / 276 patients: 0.7%, 95% CI: 0.2- 2.6% 5 / 63 known; 8%, 95% CI 1- 15% Age, gender, aneurysm size no predictor growth

Results: 2 de novo 5-year cumulative incidence ♀, 56 jr →3 mm MCA ♂, 66 jr →3 mm Basilar tip Both left untreated

Results: 5 grown 5 aneurysms in 4 patients ♀, 49 jr → ICA 3 → 6 mm ♂, 45 jr → pericall a 2 → 3 mm ♂, 66 jr → pcoma 2 → 3 mm ♀, 53 jr → PICA 2 → 3 mm → Bastip 4 → 6 mm COILED COILED

CASE Grown additional aneurysm

49 year-old woman, 5 additional aneurysms Grown left carotid tip aneurysm 3x3  4x6 mm (pcoma aneurysm 2x1 mm conform)

Results: Clinical implications 2 grown and 2 incomparable aneurysms treated in 3 patients (1.1%, 95% CI: 0.4- 3.1%) 8 patients extra imaging follow-up (2.9%, 95% CI: 0.9- 4.9%)

Conclusions Follow-up MRA 5 years after coiling has a low yield for detection of clinically relevant additional aneurysms 5-year incidence de novo formation: 0.7% (2/276) 5-year incidence treatment of additional: 1.1% (3/276)

LOTUS study group UMCU AMC G.J.E. Rinkel, neurologist B.K. Velthuis, radiologist G.A.P. de Kort, radiologist J.D. Schaafsma, neurologist resident VUMC F. Barkhof, radiologist J.C.J. Bot, radiologist LUMC P.A. Brouwer, radiologist M.A. van Walderveen, radiologist MUMC W.H. van Zwam, radiologist R. van Oostenbrugge, neurologist AMC S.P. Ferns, PhD student C.B.L.M. Majoie, radiologist (Principle investigator) R. van den Berg, radiologist M.E.S. Sprengers, radiologist J.C. van Rijn, radiologist J.J. Schneiders, PhD student P.M. Bossuyt, clinical epidemiologist W.P. Vandertop, neurosurgeon B.A. Coert, neurosurgeon St. Elizabeth Ziekenhuis Tilburg W.J.J. van Rooij, radiologist M. Sluzewski, radiologist Slotervaart Ziekenhuis B.J.C.M. Hummelink, neurosurgeon