Unruptured Aneurysms G Narenthiran L Alakandy J P Holland Greater Manchester Neurosciences Centre Hope Hospital Salford

Tools for estimating the Life-time risk of rupture & Effect of intervention on life-expectancy

Unruptured aneurysms Increasing numbers being diagnosed 45% - 80% of patients with ruptured aneurysm may die Not all rupture Treatment morbidity 0-16%; mortality 0- 25% Treat those at high risk of rupture

ISUIA 2003 Prospective Multi-centre 1692 patients did not have treatment Selection bias Not randomised Aneurysms < 2mm not included Mean duration of follow-up was 4.5 years Patients who subsequently underwent treatment excluded from analysis Included only North America and Europe

ISUIA, 2003 The best we have Findings of ISUIA (2003), could be incorporated into the global view of UIA Considered along with other data pertaining to the patient

Objective Tools for calculating rapidly at: Neurovascular MDT meetings Clinics

Method Cumulative risk (%) = 100 x {1- [(1-annual risk)/100]^years}

Maths of Probability × × 0.98 × × 0.98 × 0.98 × × (risk of no-rupture) years Chance of non-rupture = Chance of rupture = 100 – chance of no-rupture Annual risk of rupture = 2% Annual risk of no-rupture = 98%

Calculation: Simple Vs Actual SimpleActual 1% annual risk over 10 years % annual risk over 20 years 6046

Updated ISUIA (2003) < ≥ 25 Group 1 Group 2 Cavernous carotid 0003%6.4% AC/MC/IC01.5%2.6%14.5%40% Post-P comm 2.5%3.4%14.5%18.4 %50% 5 year cumulative rupture rate. Wiebers DO et al. Lancet 2003; 362:

Annual risk of rupture of unruptured aneurysm < >=25 Group 1 Group 2 Cavernou s carotid AC/MC/IC Post-P comm

Risk of Intervention Vs natural history The Risk of intervention is immediate Risk of natural history is distributed over the life-time

Need to take into out those who will have a good outcome following rupture

Life table Life-expectancy tables for Constructed abridged life-tables

Look-up tables ‘Actuarial-type’ table Gender specific Calculations performed using Microsoft ® Excel ® 2003 Table laid out using Adobe ® Illustrator CS2 ® and Adobe ® InDesign CS2 ®

‘Hope’ calculator Life-time risk of rupture of unruptured aneurysms Effect of intervention on the life- expectancy Software developed with Macromedia ® Flash 8 ® Both Windows and Mac compatible

55 year old male with sah with an incidental 5 mm Acomm Aneurysm

A 50 year old female with 8 mm rt. PICA aneurysm

A 45 year lady with 8 mm MCA aneurysm A 60 year male with 13 mm basilar artery aneurysm

Acknowledgements Mr Leggate, Mr King Mr Hutchinson, Dr Laitt Mr West, Mr Richardson, Miss Pickett, Dr Hughes, Dr Herdwardkar

Acknowledgements Mr Kirkpatrick, Mr Laing Professor Mendelow, Mr Mitchell Professor Harbaugh (Penn State) Professor Wiebers (Mayo Clinic) Professor Tamargo (Johns Hopkins)

Questions?