Advances in Interventional Neuroradiology

Dr James F PeerlessMarch 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 1994-2002– Clipped: 1070 (30.6 %)– Coiled: 1073 (23.7 %)

• Follow-up series in 2005 + 2009 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;4:203-215

• 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