One of the most controversial discussions, during the IROS 2012 meeting in Salzburg this year, developed around chronic cerebrospinal venous insufficiency (CCSVI).
The Italian vascular surgeon Professor Paolo Zamboni believes that multiple sclerosis (MS) is the result of a problem with blood flow from the brain, which could therefore be treated by opening up the affected blood vessels. The professor has developed a dilation procedure that he believes improves the symptoms in MS patients.
To this controversial hypothesis, Professor Thomas J Vogl, Director of the Institute for Diagnostic and Interventional Radiology at the Johann Wolfgang Goethe University Hospital in Frankfurt, offered a ‘cautious yes’ although he also characterised the procedure as ‘experimental’. However, Dr Jim Reekers, Professor of Interventional Radiology, at the Department of Radiology Academic Medical Centre, University of Amsterdam, dismissed the alleged connection between MS and CCSVI: Prof. Zamboni’s hypothesis has already been scientifically disproved; it is merely the patient forums on the internet that keep this ‘message of hope’ alive.
Professor Dierk Vorwerk, Consultant at the Institute for Diagnostic and Interventional Radiology at Ingolstadt Hospital and German Congress President of IROS 2012, also doubts Prof. Zamboni’s studies: ‘The data all come from non-independent sources, i.e. mostly from Zamboni himself, or from his followers. All others who have tried to get to the bottom of this syndrome have not been able to find any proof.’ It could therefore be the case of a chimera being chased, he suggested. ‘The problem is that the procedure is already being offered as treatment – for payment. It is therefore, in the first instance, a business model that plays on the desperation and hope of patients,’ he added.
Definite answers will probably only result from a large study, which was initiated by the Canadian Ministry of Health.
‘Hot topics can be found wherever there are turf battles, i.e. where several different medical disciplines fight over who treats the patients, explained the Austrian Congress President Professor Siegfried Thurnher, Head of the Department of Radiology and Nuclear Medicine at the Hospital of the Order of Saint John of God in Vienna. His own irritation is that cardiologists increasingly act like vascular specialists and carry out minimally invasive interventions in the renal, carotid and leg arteries. ‘Numerous vascular surgeons are also getting a taste for this, now calling themselves ‘endovascular surgeons’ and taking over our procedures.’
From other disciplines come grumblings that interventional radiologists have developed new, gentler therapy concepts that lead to the same results as those achieved with previously established treatments -- typically, the uterine artery embolisation for fibroids. Whilst gynaecologists often tend to remove the uterus in patients suffering fibroids, radiologists guide a catheter into the uterine artery, cut off the blood supply to the fibroids and thus starve them. ‘Preserving the womb, apart from the fact that the procedure is also minimally invasive, is the significant advantage of this procedure, Prof. Thurnher explained. ‘However, gynaecologists want to claim the womb for themselves and are worried that this more gentle treatment is being offered by radiologists.’
A further field of deployment for interventional radiologists is the treatment of acute strokes. In some centres, around 20% of severe strokes are already being treated with microcatheters, the professor pointed out.
Along with controversies, all in all IROS 2012 (supported by CIRSE – the Cardiovascular and Interventional Radiological Society of Europe), did justice to its image as a showcase for interventional radiology.
Among innovative procedures presented was renal denervation, based on the following concept: Research results have shown that high blood pressure (BP) is partially caused by the kidneys. BP can be lowered by the destruction of those nerves that connect the kidneys with the sympathetic nervous system. To interrupt the abnormal regulation of BP, the nerves are cauterised with the help of high-frequency radio waves from a tiny high frequency probe inserted via an artery in the groin under local anaesthetic and guided towards the renal artery. ‘In around 85% of patients we observe a significant effect and BP falls by between 15 and 60 mm HG,’ said Professor Michael Uder, Director of the Institute of Radiology at the University Hospital Erlangen.
Procedures such as percutaneous alcohol ablation, radio frequency ablation, microwave ablation and cryoablation will soon face competition from Irreversible Electroporation (IRE), a procedure that originated in the field of food and bio process engineering. An electric field acts on the tumour cells; nanopores develop in the cell walls, the integrity of the cells is destroyed and they subsequently die.
Dr Ortrud Kosiek, senior house officer at the Clinic for Radiology and Nuclear Medicine at Otto-von-Guericke University Magdeburg, described the special characteristic of this procedure: ‘Collagen and elastic fibres do not respond to this procedure. Key structures and vessels therefore remain, tumour cells are destroyed.’ His regret is that there is not much data available on this procedure, as yet.