Advances in Interventional Neuroradiology Dr James F Peerless March 2014

Introduction

Interventional Radiology Endovascular, catheter-based techniques using fluoroscopy and angiography – To diagnose and treat vascular diseases of the CNS Examples – diagnostic cerebral angiography – acute endovascular stroke treatment – revascularization of carotid and intracranial stenosis – cerebral aneurysm

The Past

From Small Beginnings Catheterisation of arterial cerebral vessels first described in 1931 by French neurologist, Dr Moniz. Access limited by size of catheters – Transfemoral and transcarotid approaches Treatment options: – Electrothrombosis (1964) – Detachable balloons (1970) – Injection into aneurysm Iron Microspheres Microcatheter developed in 1988 – Allowed direct probing of aneurysms

Coil Development Free coil occlusion – Detachable coils via a delivery wire – Separated with direct current – Guido Gugliemi (UCLA), 1991 Initially used in non-ruptured posterior aneurysms, poor grade SAH and those unfit for surgery Now the treatment of choice, >90% Electrolysis detachment replaced by mechanical/pressure devices

Coil Development

The Present

Aneurysms Coiling – Bare platinum coils – Bioactive PGA coils Increased thrombogeneity and fibrosing induction Stenting Balloon-remodelling and embolisation Flow-diverters – devices are designed to achieve aneurysm occlusion through reconstruction of the diseased segment of artery

Aneurysm Treatments

Balloon and Onyx Embolisation

Collected data in 2143 patients between – Clipped: 1070 (30.6 %) – Coiled: 1073 (23.7 %) Follow-up series in conferred a survival benefit of at least seven years Increased (small) risk of rebleed Future bleeds “essentially eliminated”

Previous small single-centre trials showed promise of bioactive coils Bare platinum versus Cerecyte coils RCT (non-blinded), n = 500 Non-significance demonstrated, but – Increased periprocedural M&M – Poorer 6-month outcome (mRS)

ATENA Trial, 2010 – Data collected in 622 patients in France and Canada between 2005 & 2006 – Coiling and remodelling associated with better radiological outcomes than stenting – Factors for a favourable outcome Age < 65 Aneurysm diameter < 6 mm Dome-neck ratio > 1.5

Brain AVMs Embolisation techniques – nBCA n-butyl-cyano-acrylate – Onyx licensed in 2005 polymer in organic solvent Results from single-centre studies only Trade-off between long- and short-term gain – Pierot et al., 2009 (J. Neuroradiol.) >60% occlusion rates in 73% on 116 patients 2% mortality, 8% morbidity at one month Increased risk of recanalisation with reduced occlusion Periprocedural morbidity – 12.2%: Hauck et al., 2009 (Am. J Neuroradiol.) – 19.5%: Panagiotopolous et al., 2009 (Am. J Neuroradiol.)

The Future

Future Advances Aneurysms – Problems are the same as in the past Tricky aneurysms are large with wide necks Difficult to treat with high recurrence rates – flow diverters – Bettering the understanding of: aneurysm formation, growth, and rupture AVMs – New embolisation materials

Reference Schumacher M, Weber J. Aneurysm Treatment – a Neuroradiologic Success Story. Clinical Neuroradiology, 2008;4: Gounis J, De Leo III M, Wakhloo A. Advances in Interventional Neuroradiology. Stroke, 2010;41:e81-e87 Chen M. Interventional Neurology – Recent Advances & New Applications. US Neurology, 2011;7(1):37-40