Toshio Hyogo, current president of the World Federation of Interventional Neuroradiology (WFITN) and 2004 president of the Japanese Society of NeuroEndovascular Therapy tells NeuroNews how he found his way into interventional neuroradiology and describes some of his most memorable cases and advice from mentors. Hyogo is chief, department of Neurosurgery at Nakamura Memorial Hospital in Sapporo, Japan.
How did you find your way into neurosurgery, and then, interventional neuroradiology?
My graduation from medical school overlapped with the early stages of computed tomography. I felt that this technique had huge potential, the ramifications of which we were only just beginning to fathom. Then, I encountered the Tracker catheter (microcatheter) in 1988 which led me on to interventional neuroradiology because navigating intracranial vessels with a therapeutic intent attracted me and I felt that this was a future full of possibilities.
Which innovations in interventional neuroradiology/endovascular neurosurgery have shaped your career?
The Guglielmi Detachable Coil was a revolutionary innovation for endovascular treatment and I found this to be true in my career as well. This coil was the first device for safe and reliable aneurysm treatment, and it has been used for over 20 years. I am sure that the present belief in endovascular treatment and new devices owe much to this coil and related technology.
Who were your mentors in the field and what do you still remember of their wisdom?
My particular mentors were two Japanese physicians. The first, Dr Junichi Nakamura, the previous chief and owner of our hospital led me to neurosurgery and taught me the importance of patient care and always remaining in contact with the patient. He was quick to grasp potential future of endovascular treatment and supported me to get into interventional neuroradiology. Akira Takahashi, a professor at Tohoku University, taught me the first steps and primary techniques in endovascular treatment.
I also have two mentors outside Japan. Michel Mawad, a professor at Baylor College of Medicine, Houston Texas, USA, became a mentor when I was in Houston in 1996. This was just before the introduction of the Guglielmi Detachable Coil to Japan and I had gone abroad to study aneurysm coil embolization. He taught me extensively about endovascular treatment and I appreciated his kindness in my first uneasy experience of life abroad. Luc Picard, a professor from the Department of Neuroradiology, Nancy University, France, was a mentor when I was in Nancy in 1997. We had many cases of aneurysm coil embolization and cerebral arteriovenous malformation glue embolization at Nancy, and Luc taught me not only the clinical aspect but also a part of the spirit and essence of neuroradiology which originated and developed in France.
Could you describe an early moment in your career in interventional radiology where you were amazed by what the specialty could achieve?
I was amazed by what interventional neuroradiology could achieve when I saw a patient recover dramatically from symptoms on the angiography suit table during my first stroke treatment. The patient had a right hemiparesis and speech disturbance and was diagnosed with a left middle cerebral artery occlusion. I then navigating the microcatheter to the occlusion site and infused urokinase. During the infusion, she suddenly spoke and intended to remove her oxygen mask with her with right hand. Angiography revealed a complete re-opening of the occluded vessel.
Can you describe a memorable case and how interventional neuroradiology came to the rescue?
A 17-year-old high school girl suffering subarachnoid haemorrhage was transferred to our hospital. The diagnosis was pial arteriovenous fistula (an arteriovenous malformation). I treated her by endovascular embolization using glue with a flow control balloon catheter.
Using two catheters in one branch of the middle cerebral artery was a brand-new, revolutionary technique for me at that time, and her fistula was treated completely. I was so very glad that she made an impressive recovery and went to nursing college and then to become a midwife.
Another case when interventional neuroradiology came to the rescue was in the case of a pituitary tumour. During an operation to remove the tumour by trans-sphenoidal approach, one side of the carotid artery was injured and the neurosurgeon could not control the haemorrhage. We carried out a rescue treatment with endovascular technique by coil embolization of the injured carotid artery, and the haemorrhage stopped.
What is the research you have done that has been most rewarding?
My hospital is the Stroke Centre of Sapporo city, so I have treated stroke patients ever since the microcatheter was first introduced. I have got good results by including cerebral blood flow factor measurement to the indication criteria. My work was also instrumental in organising and performing a Japanese randomised controlled trial for endovascular stroke treatment, the Melt-Japan study. Evidence from the study contributed to the introduction of rtPA in Japan and I am very proud of the success of Melt-Japan.
How does the practice of interventional neuroradiology in Japan differ from Europe and North America?
Traditionally, cerebral angiography has been performed by neurosurgeons in Japan and this has continued on into endovascular treatment. The Japanese Society of NeuroEndovascular Therapy (JSNET) has about three thousand members and over 90% of the members are neurosurgeons. This is a big difference from the West. Recently, the number of neurosurgeons who are devoted to endovascular treatment is increasing in the USA. I think it is very important that endovascular treatments should be performed by doctors who have experience of watching cerebral aneurysm from the outside or who know how the plaque is fragile at carotid endarterectomy.
Another difference is in the integration of the cases. In Japan, neuroendovascular treatment is performed in many different kinds of hospitals—university hospitals, municipal hospital and even small private hospitals. In the smaller institutes, experience with endovascular treatment is usually very limited. So we had to meet the challenge of how to ensure a standard level of endovascular treatment for the patient. This became a very important problem in Japan. One of the answers was to create a JSNET specialist qualification system, which was established in 2000. I wrote the paper in Interventional Neuroradiology. I am very proud of this system, a specialist examination system which is constant and fair. With the expansion of interventional neuroradiology, the same problem will be apparent in many countries. We hope our specialist qualification system will be a model case to help solve this problem.
What do you hope to achieve in your term as president of WFITN?
WFITN is seeking to standardise fundamentals that are common all over the world, even under different medical systems or different levels of the treatment. One of the main goals in establishing WFITN is improving the training for endovascular treatment. On training standards, I took over from the former WFITN president Pierre Lasjaunias. Luc Picard arranged the charter of training for endovascular treatment and wrote the paper in Interventional Neuroradiology with the support of many members. In my term, I would like to focus on arranging the society’s system including bringing in the constitution. This work is underway and will continue with the next president. As for the WFITN scientific meeting in Africa, we hope this meeting will be a one step of expansion of neuro-endovascular treatment in Africa as previously experienced in east Asia, Japan, Korea and China.
What are three key questions in interventional neuroradiology that you would like to see answered?
- What is the final design of clot removal devices in stroke treatment?
- Is it possible to have surface modified devices such as coils, stents and diverters?
- Is it possible to have a computer-assisted endovascular treatment guiding system?
What are the new techniques/technologies that you are watching closely?
I am very interested in nanotechnology and how it will influence interventional neuroradiology. I expect that we will soon see applications of nanotechnology in interventional neuroradiology such as in surface modification, smooth finishing of devices or in the evolution of new device materials to replace metal.
What are your interests outside of medicine?
I am interested in sports and enjoy watching football games in Europe, baseball games in the USA and of course, in Japan. I also enjoy playing golf.
In football, I have enjoyed watching Series-A, Premier League and La Liga matches. When it comes to the FIFA World cup, I have been to games in all the World Cup games from1994 in the USA to 2006 in Germany. I did not make the 2010 World Cup in South Africa as it was too far from Japan, but I had to go there for the WFITN meeting this year!
In baseball, I am a fan of the Nippon-Ham Fighters, the professional baseball team in my city, Sapporo.
I play golf with the Sapporo club and my handicap is now nine. Golf is a sport where you can never be “perfect”—not even Jack Nicklaus or Tiger Woods can be.
I think that that is an attractive point for all golfers, juniors, seniors, professionals and beginners. I believe practice is the only way of improving and getting close to “perfect”.
Chief, Department of Neurosurgery at Nakamura Memorial Hospital in Sapporo, Japan
Endovascular treatment of cerebrovascular disease, aneurysm and stroke
1979 Graduate of the Sapporo Medical College, Sapporo, Japan
1979 Medical License from Japan
1979 Department of Neurosurgery, Nakamura Memorial Hospital, Sapporo, Japan
1984 Clinical staff of National CardioVascular Center, Suita, Japan
1985 Board certification of Neurosurgery
1996 Clinical fellow, The Methodist Hospital, Department of Neuroradiology, Baylor College of Medicine, Houston, USA
1997 Clinical fellow, Department of Neuroradiology, Nancy, France
1997 Chief of division of Surgical Neuroangiography, Department of Neurosurgery, Nakamura Memorial Hospital, Sapporo, Japan
2000 Board certification as consulting specialist of JSNET
2004 Co-director of Department of Surgical Neuroangiography, Neurosurgery, Nakamura Memorial Hospital, Sapporo, Japan
2004 President of Japanese Society of Neuro-Endovascular Therapy (JSNET)
2006 present Executive board member of JSNET
2007–2009 Vice president of WFITN
2009–2011 President of WFITN