It is a great honor and pleasure to give the 2020 Donahi Lecture and the title is the Evolution of Cerebrovascular Neurosurgery in Finland, a European Perspective. I thank Dr. Welch for this wonderful invitation and also Dr. Friedlander for inviting me to the WNS-CNS executive committee member as an international liaison. Both are great neurosurgeons and great friends. Thank you very much. I have no disclosures. I personally didn't meet Dr. Donahi ever. Here he is in a picture with Professor Jasagil, whom I met later on. I spent one month in Little Rock in 2000 and it was a great month. I learned a lot. Every day we saw one hour of videos of how to open the sylveon fissure and other basics and tricks in addition to observing his surgeries. What a wonderful month. Later on in 2003, during our life course, I was assisting him in a posterior fossa surgery in this picture. He came to Helsinki for three times to our life course to perform surgeries. European Union had 500 million people before the Brexit, which reduced the number of people with 65 million. Finland has 5.5 million people and has some special things. The only real Santa Claus comes from Finland. All others are fakes. We have a lot of saunas, more than 3 million saunas for 5 million people. Nokia has been our pride and joy, especially 15-20 years ago, 39% of the cell phone world market was dominated by Nokia. Now it is a network company producing 5G networks. We have also now cell phone games, Clash of Clans, Clash of Royals have brought more than all Star Wars movies together, money, and Angry Birds also comes from Finland. We have a special competition that has been going on for 20 years, cell phone throwing world championships, the world champion being 136.75 meters. We have shipyard industry, most of the Caribbean cruisers are made in Finland, and funny enough we drink most coffee and milk in the world. We are ice hockey and F1, Formula 1 world champions, and we have a great public school system. The highest density of heavy metal bands, blondes, and PhD per capita can be found in Finland. We have the most stable and free society, free press, lowest corruption and crime rate, equality of genders, almost 50% of neurosurgeons are women. We have the cleanest air and water, here you can see a lake view from Finland. We have 190,000 lakes, so we never have lack of water. According to the United Nations, Finland is the best place for a mother to live, and there has been a decade-long support system with 11 months of maternity leave plus altogether three years with reduced salary. You can stay out of work to raise your kids. Still we have the lowest birth rate in the world, together with Japan, and surprisingly also Italy and Spain, for various reasons. According to the United Nations and their survey, we have been the happiest nation three years in a row. This has definitely changed from the 60s when we had the highest suicide rate, but there was a big prevention program and things have definitely changed. Less than 10% of our gross national product goes to health care. Still according to studies, we produce the highest quality and availability in health care, reflected also by a very low mortality in the unfortunate COVID pandemic. So only less than 200 people have passed since April 27th to COVID-19. Also small population and early social distancing have helped definitely. Finland is perfect for long-term follow-up studies because of our small population, high quality health care system. We have five university hospitals treating patients with a catchment area, so selection biases are minimal. We have registries and statistics Finland, and also when patients have an identification code, you can combine all the data. You can find patient files or the reports from anywhere when you have the permission to reach them for scientific purposes. Patients are also willing to participate in long-term follow-up studies and retrospective is really not bad as all patients are included and there are no randomization biases. We have also of course produced prospective studies which have problems in randomization as we all know. Neurosurgery in Finland started in 1932 when Helsinki department was established. Helsinki treats the southernmost part of Finland, 2.2 million catchment area. Then Turku here on the west coast was established in 1967 and last year, Helsinki and Turku treated 65 to 67% of aneurysms endovascularly. Oulu was established in 1975 and 75% of aneurysms are treated endovascularly. Kuopio was established in 1976. The university hospital had neurosurgery since then and 60% of the patients are treated endovascularly and Tampere, 67% of the aneurysms are treated endovascularly. The first aneurysm surgery was performed in Finland in 1937 and we have around 80 neurosurgeons. Helsinki University Hospital is a giant, the largest hospital network in Europe with 23 hospitals, 25,000 employees, 3,100 doctors and almost 100,000 surgeries in more than 3,200 beds. This is an overview of Helsinki. Helsinki is the capital of Finland with 600,000 people. Altogether the capital area is 1.2 million and Helsinki catchment area for neurosurgery as mentioned is 2.2 million. In Helsinki area we have 300 islands. It is a wonderful city for sailing, outdoor activities, museums, concerts, etc. We have four seasons, summer is very nice, warm, light. We have beautiful foliage and up north in Finland we have fantastic cross-country skiing and downhill skiing with a lot of snow during winter but as there is definitely a climate change in Helsinki we do not necessarily have snow, at least not much. This year almost nothing and this picture I took in February 23rd with no snow it looks very much like spring in Helsinki. Helsinki Neurosurgery was established in 1932. The first chairman and the founder of Finnish Neurosurgery is Arno Snellman here. He was succeeded by Gunnar Ravjörkesteen and then Henri Trupp. Olli Heiskanen was in between the chairman and then many of you know Juha Hernesniemi who was my predecessor. I became the director of neurosurgery in 2015 and this is now our vascular team with five vascular neurosurgeons, Leena, Miikka, Aki, Martin. There is a subspecialization within the group so two of us do AVMs, two of us do bypasses, two of us do janettas and posterior circulation aneurysms, all of us do anterior circulation aneurysms and cavernomas. We have a 24-7 on-call team and now Justyna was my fellow and is joining the vascular team gradually and Ville just finished his residency and is joining my fellowship next year. Rahul is a resident who is in hybrid training for endovascular. He did his first basilar tip aneurysm at the age of 27, endovascularly clearly showing that the learning curve is very steep in endovascular. In Europe we have around 20 hybrids so far and I will come back to that. We need to train more and training has begun. Helsinki and Finland has a lot of input on PhDs and scientific papers on vascular especially SAH risk factors including the aneurysm wall, incidence of SAH, characteristics mainly surgical techniques and long-term prognosis on aneurysms. We have a database in Helsinki of more than 13,000 patients and a database on AVMs more than 800 patients and we have published extensively on this. Also on dural AV fistulas, cavernomas, intracerebral hematomas and moyamoya disease the incidence of which is very low in Finland. SAH in Finland, aneurysm prevalence is as elsewhere 2% and now that there is less smoking, Finns are one of the least smoking countries in the world nowadays. The incidence of SAH has gone down to 7 to 100,000 per year. So also it seems that we have less MC aneurysms than we used to together with the lower incidence of SAH. Smoking and hypertension are the highest risk factors for rupture and we have studied the aneurysm wall and inflammation in it and the idea is to image those aneurysms that have a higher risk for rupture and then treat those ones. This paper published in Neurology in 2016 showed that the incidence of SAH is decreasing together with decreasing smoking rates everywhere. Rise of ruptured intracranial aneurysms is also decreasing and we have less and less giant aneurysms. In Greece where smoking is more common, SAH is also more common and incidence being 26 to 100,000 which is clearly higher than in other countries where there is less smoking. Japan is also going down with their numbers. We participated in Dr. Gunnell's and Lifton's aneurysm gene study which didn't find any specific aneurysm gene that could be studied and according to a large Nordic twin study of more than 6 million follow-up years, SAH appears to be mainly of non-genetic origin and familial cases can mostly be attributed to environmental risk factors such as smoking and hypertension. So we have studied the aneurysm wall, we have a tissue bank of more than 700 samples collected after clipping for research and the aneurysm wall definitely is a dynamic thing. Many things going on, mostly inflammation and there is expression of metalloproteinases, growth factors which can be affected pharmaceutically, also hemodynamics play a role. You can divide aneurysm wall types into four, A being almost like a normal wall except that lamina elastica internale is missing, then you go to a more degenerated ABC and D type is with a very thin wall, highly degenerated, higher risk for rupture and there is organized thrombus inside that also keeps up inflammation and affects the wall. The thinner the wall, the higher the rupture risk which makes sense and also you can see that there is a lot of complement activation in the D type as a sign of inflammation according to the surface area, there is more of this brown color in immunohistochemistry showing higher inflammation. Then a few words about our AVM database since 1944. We have more than 800 patients and we have published in Neurosurgery in 2008 and 2011 our series and to make it short previous rupture deep location, infratentorial location and large size of the AVM are independent risk factors for rupture and if you follow these patients long enough you will see that during 20 years follow up 45% of the previously ruptured AVMs rupture again and also the risk of rupture for infratentorial ones is 76% during the 20 year follow up for deep 53, large 52 and the ones with deep brain is 52% risk of rupture during 20 years. And if we compare to Aruba study we have the same natural history, the short follow up time of Aruba if you compare that to our longer ones so the conclusion is that still the natural history is about the same 2.5% risk of rupture per year. If you follow long enough and you don't do anything with an AVM half of the patients die due to the AVM but if you treat it completely the patients have almost like a normal life span compared to a mass general population in Finland. A recent study on KRAS mutations in AVMs opens new highways to pharmaceutical therapy and also shows that not all AVMs are inborn, many of them progress during life as you can often see in clinical practice. Then a few words on how to become a better neurosurgeon. You should travel and see, you should go to different ORs in different places of the world to see, learn from the masters, you can also invite masters to your own place and we have had a great pleasure of having an annual international microsurgery life course in Helsinki where we have invited many of the world's stars to do surgery in addition of doing it also ourselves. Unfortunately this year would have been the 20th celebration but due to the pandemic we had to cancel the course. Cadaver courses are important and also lab training because in bypass surgery the numbers are going down in most of the places so you need lab training with rodents and also silicone tubes and that makes you also a better neurosurgeon even if you don't do bypasses that regularly. Networking is important, you form friendships all over the world, nice to go to see friends in different places, learn surgical anatomy, watch surgical videos, now it's easy with your smartphone, many journals have their own video archives and most of all record and watch your own surgeries, you will be surprised to see yourself in action. Meaning invasiveness and quality of life are key words and must be taken into account. We studied our patients operated on in a series of prospective consecutive unselected of more than 400 patients who underwent elective craniotomy between 2011 and 12 and 94% of the patients were very satisfied with the treatment and the complication rate was very low. You have to be open to publish your results also adverse effects and complications. In addition to developing your micro neurosurgical skills you have to follow what's going on in endovascular treatment so we were included in Dr. More's course in Paris between 2007 and 15 showing surgeries from Helsinki live by a satellite. Paris is known for endovascular treatment, almost 95% of the patients treated by that method and Helsinki was known for micro surgery 95 to 90% of the patients were operated on at one point. That has changed and now we have collaborated a lot with ENS vascular and I'm a board member in ENS vascular committee as an international liaison like I am in the AA and the CNS we have good collaboration we have European and American speakers in this in September. Here we are with Jacques More, Peter Vajkoczi, David Langer, Bhadvan Redzvan on the rooftop of a hotel and it's fantastic collaboration. In Europe you can also train to be in the neuro interventionalist as a neurosurgeon so you need 12 months dedicated training in diagnostic neuroradiology and 24 months in interventional and this 12 month clinical training in neuroscience can be included it is during your residence in neurosurgery. So there's a trend in Helsinki since 2015 when I became the director to go towards more endovascular and this is evidence-based especially concerning vertebrobasilar aneurysms most of them are treated endovascular nowadays except for some pica aneurysms. Patients income and follow-up stay at neurosurgery because the patients come to neurosurgery, knowledge of the disease and research is mostly at neurosurgery despite the angiosuite and equipment belonging to radiology. These sessions are made together with interventionalists and we have every morning an x-ray meeting where we see results of endovascular microsurgery they are exposed and discussed. Doors open to hybrid training 2017 after having given more cases to neuro interventionalists. This is natural as door swings both ways. Training of vascular neurosurgeons and hybrids in the 20s in Finland and Europe it has some challenges and changes as SAH incidence is going down we have less aneurysm patients, ruptured aneurysms are getting smaller so does it mean that they become easier? Can be but some small aneurysms can be very difficult if we talk about blisters but definitely we have less giant aneurysms and thereby maybe surgery is not at least becoming more difficult as was thought at one point. Also we see that in Helsinki we don't have crossovers from endovascular to neurosurgery so also we avoid operating there's no need to operate endovascular treated aneurysms later. Expectations of the society for mini invasiveness and quality of life are increasing and due to less aneurysm patients one-year fellowship in open micro neurosurgery is not enough it is just the beginning and longer times are needed for training. Neurosurgeons definitely should do endovascular and treat and follow the patients and do research. Endovascular equipment are definitely more expensive and in ruptured aneurysms ICU costs are similar according to a Finnish study but still endovascular may save money with shorter hospital stay and shorter sick leaves especially in unruptured aneurysms. Future perspectives on vascular neurosurgery there is and there will be a need for vascular neurosurgeons but job description changes there will be need for hybrids and also vascular neurosurgeons are excellent skull base surgeons because often these tumors and are involved with vasculature so often vascular surgeons do skull base surgery and this goes very well also in the future. Centralization of the patients and vascular on-call teams including hybrids are very important and within a single department and vascular team subspecialization is important. Bypasses, AVMs and posterior circulation aneurysms are not for all vascular neurosurgeons but should be also centralized. At least two persons in a vascular group should do these special procedures and there should be enough neurosurgeons to keep up a vascular on-call system. Fellowship should be done in high-volume centers but one-year fellowship in open microsurgery is not enough. You have to continue developing your skills later on. Bypasses for moyamoya are still needed but perhaps in the future exoscopes will replace microscopes in these procedures. Once there will be medication for moyamoya the number of bypasses may go down as it has happened with flow diverters for instance in intercavernous aneurysms and in most centers bypass numbers are going down except for some tertiary high-volume centers. Centralization within countries and even continents is necessary and lab training with silicone tubes rats and mice is necessary in times of less bypasses and less exposure to aneurysm surgery. Neurosurgeons should go to endovascular training and with radial artery access angiographies and procedures are becoming more and more elegant. Neurosurgeons in the United States are ahead in experience and training and it has been very wise to start this hybrid training. Europe is behind that but also now increasing training but Europe has been ahead in devices. We get all the new stuff much earlier than our colleagues in the United States. Future perspectives on vascular neurosurgeon prevention, prevention, prevention. The best way to treat is to prevent and by reduced smoking incidence of aneurysms and SAH has gone down and also smoking affects AVMs. Hypertension is an important risk factor both for aneurysms and intracellular hemorrhages and treating hypertension effectively has very good consequences and has gone has affected also probably the incidence of SAH and it's going down. Risk factors go in families and so far no single aneurysm gene that could be detected has been found. Microsurgery still in 2020 is a gold standard in MCA aneurysms as re-canalization is very common after endovascular and selected AVMs, cavernomas and hematomas still need surgery. Endural AV fistulas, endovascular has almost completely run over microsurgery. Identification of aneurysm wall types and inflammation is pertinent and I strongly believe that within the next few decades pharmaceutical therapy will come to prevent rupture in unruptured aneurysms and no invasive treatments may be needed. The same has happened in gastric ulcers which are an infectious disease, aneurysms are an inflammatory disease with other mechanisms that can be affected like hypertension. In AVMs and cavernomas pharmaceutical therapy studies are already going on. I want to thank for this great honor I want to thank my national and international colleagues AANS, CNS and ENS CV section executive committees where I'm a member. I want to thank World Academy and I want to finish my presentation to this very nice slide. This was taken this picture in Prague in September 2018 at the World Academy dinner. We have a wonderful group of people, good friends who make this job even better. Thank you very much.

Cerebrovascular Neurosurgery

Finland

European perspective

Aneurysm prevalence

Subarachnoid hemorrhage

Endovascular treatment