Baptist Health Miami Neuroscience Institute invites Dr. Daniel Barrow to discuss the latest techniques and research advancing cerebrovascular surgery and stroke care.
Yeah. Mhm OK, I'm gonna start, uh, I'm gonna start right on time. It's 4 o'clock. Um, thanks to everybody for coming. Um, this is the 3rd invited lectureship out of 12 that we've done. Um, we have, um, covered a number of the disciplines. I hogged the invitees for the most part for the first year, but next year we'll solicit um recommendations for uh the various topics. Um, today we have a cerebrovascular lectureship. Um, and it's we named it the Charles G. Drake cerebrovascular radio cerovascular surgery lectureship. Uh, in honor of, um, Charles Drake, so many of you wouldn't know who Charles Drake was unless you were a slightly older erbrovascular surgeon, uh, but he was a unique person. Um, he was born in Windsor, Ontario, and he spent his entire career at the University Hospital in London, Ontario, could have moved anywhere, didn't want to move. Favorite hobbies were fishing, golfing, and flying. Had a little plane flew up to his cottage. On weekends and stuff, um, and he was very famous for his vertebrovascular artery aneurysm surgery. This is before the days of interventional radiology, but he was one of the first neurosurgeons to promote endovascular treatment. Of of aneurysms, and he prompted his interventional radiologist to think outside the box and do creative things. Um, he was very humble about his accomplishments, but What he had 1800 basler tip aneurysms or something he did with Sydney Peerless. And I put in the description, uh. Beside his photograph that will go on the plaque that um and I got approval from Jim Drake, his son, who's a pediatric neurosurgeon in Toronto. I called Jim and I sent him the the verbiage for the description and and Dan remembers this, that he was invited speaker, um. Yeah, it's the wrong uh link. Yeah, the, um, I'll send you an email with the right. And he said, I'm not here to tell you about my successes. I'm here to tell you about the brains I've wrecked. And then he basically, and I was like, I was a resident at the time and I was shocked that he would say that, but cause, you know, I thought every all these famous people were. You know, infallible, and then back in the day, he went on to say, you know, Mr. McDermott, who had a, you know, remember he used the person's names because that's how well he remembered um the individual cases and tried to tell us what not to do. Based on his, I think, errors of the past. Um, he was very successful, um, academically, he, um, you know, was president of numerous societies which you can So far as requesting remote control of your screen. So now what do I do? Oh, You know how to do? So, um, anyway, he was, even though he was in Little London, Ontario, Canada, he was the president of uh more American neurosurgical societies and international societies than he was Canadian ones. So, um. And stuff. I don't know approved declined, OK. And um So, and he received the Cushing medal from the WNS and he received the highest order a civilian can get in Canada. It's called the Companion. Order of Canada. I think Jim Rutka has also received the same medal as a Canadian from Toronto. And um I've known Doctor Barrow since 1997 when he was a guest lecturer at UCSF. Uh, I asked him how he could become, how he became a chairperson at such a young age in 1997. Remember talking to um down radiation oncology outside the Gamma I remember. I don't know if you do, but I remember. And um Dan's been uh chairman of the department of neurosurgery at Emory University in Atlanta since 1995. Uh, he started his training in, in, uh, uh, in Atlanta Demery, did fellowships with Robert Spitzler, I presumed Thorson in Rochester back in the day, and I found out last night at dinner that actually Dan was set up to do his errovascular fellowship with Charlie Drake, um, prior to meeting his current wife, which changed his plans. And uh Doctor Drake was not upset, very understanding the whole thing, and they, they turned out to be uh close friends over the years. Dan's got a very impressive CV. It's humbling. You feel inadequate when you read a CV like his in terms of his leadership and his uh participation. He's had over 40 invited lectureships in cerebrovascular surgery. He, he received the Drake Award and was a Drake lecturer for the joint section ANS CNS cerebrovascular surgery section. He's a member of 25 editorial boards, lots of papers, book chapters, and 79 visiting professorships, which is unbelievable. 80, including this one now and Uh, he held many positions in the American Board of Neurological Surgery, organized neurosurgery, too many to list. Um, he's CEO of the physician group practices at Emory Healthcare. Is that correct, Dan? Not anymore? OK. But he was past president of the Congress of Neurological Surgeons, uh, Academy of Neurological Surgeons, Society of Neurological Surgeons, Georgia Neurosurgical Society. When he gave the Academy talk during his presidency, he had all this animation and everything. I was, and I went up to him afterwards and I said, I said, did you do all that animation yourself? And he said, yes, I hired an artist and we drew sketches and compiled all these little drawn images into like a, you know, pictogram, and I said how long did it take? he said 5 months. So he worked on his talk for 5 months, which to me is it sounds like a record, but we're delighted that he was able to come and we're looking forward to hearing about the evolution of cerebrovascular surgery since the days of Charles Drake. Well, this is the title of the uh talk that Doctor McDermott gave me and being an obedient person that's uh partly what I'm gonna talk about, but also being somewhat of a politician, uh, that answers the question that I wanna answer, not the one that was asked. I have a subtitle, uh, that is, uh, what do we have to fear? So to understand where we came from, from the time of Drake, we must understand how we actually got here in the first place uh before Drake or any of the rest of us were here. The development of the field of neurosurgery is one among the very great triumphs of Homo sapiens. Although we have evidence of trephination dating back 10,000 years, it took millennia for Homo sapiens to evolve the ability to do that rather simple task of drilling a hole in somebody else's skull. It took only another 11,000 years from trephination to modern neurosurgery and this past century has witnessed unparalleled advances that we have, uh, we have come to expect and one of the human characteristics uh that may dictate our future is a human flaw that has permeated history and that flaw is called complacency. It it often follows a period of success, and it is that that we really need to fear I think in the future and I'm gonna talk a little bit more on that flaw later, but first, let's look at how we got to where we are before Drake or any of us were here. I think it's a fascinating story. The genesis and evolution of the field of neurosurgery is an interesting chapter in the history of medicine. Much had to happen before our specialty could even be imagined. We know that ancient man performed primitive cranial surgery, but what had to occur before that initial venture into the human skull? First, we needed humans. 65 million years ago, dinosaurs became extinct, opening the opportunity for the evolution of mammals on Earth. It took more than 60 million years, but 2.3 million years ago, Homo habilis, the first of the genus Homo, evolved. His brain was slightly larger than a chimpanzee. He used simple stone tools and walked upright, but didn't talk. 400,000 years later, 1.9 million years ago, Homo erectus evolved. His brain was 50% larger than Habilis. He used complex tools such as spears and hand axes. He was the first to leave Africa. It took him another 1.5 million years to make one of the most important discoveries that would alter the course of evolution. Through a combination of luck and talent. Erectus prevails. And in Africa, he is about to take what may be the biggest leap in human history. Erectus is the first to master fire. This skill changes the course of human evolution. Harnessing fire may trigger a cascade of changes in erectus's behavior, body, and brain. After fire, erectus can sleep on the ground as flames keep carnivores at bay. He is then free to evolve arm and hand shapes for goals other than hoisting himself into branches. But the control of fire has an even more profound effect on the life of erectus. Cooking Fire and cooking could have cut 5 hours of chewing a day down to 1. Fast calories from cooked food drive a growth spurt. Erectus becomes 50% taller than earlier humans and reaches our own height. Cooked food requires less digestion, so his intestines and rib cage get smaller. Thanks to softer food, the erectus's jaw muscles shrink, freeing the skull and the brain to get bigger. A bigger brain and a powerful new tool. Fire The ability to manage fire provided for the evolution of Homo sapiens 300,000 years ago with far more sophisticated skills, language, music, art, Homo sapiens was still a hunter-gatherer, but it developed a far greater capacity to think, and more importantly, to imagine. Without imagination, there can be no invention, no art, no religion, no language, no brain surgery. The oldest trephinations from 10,000 BC have been found in northern Africa. Stone tools were used by urly hominids to perform one of the earliest surgical procedures of which we have evidence, perforating the skull to let out demons or to release insanities resulting from head injuries. There is no evidence these ancient humans performed surgery on the brain, and therefore cannot be regarded as the true beginning of the field of neurosurgery. Imitep, founder of Egyptian medicine, was the earliest known practicing physician. He described stroke and recognized head injury and would elevate a skull fracture as described in the Edwin Smith papyrus around 3000 BC. Around 300 BC, the Greek Alexandrian School of Medicine performed open dissection as part of formal teaching. Hippocrates understood head injury and primitive cerebral localization. Galen was responsible for the most prodigious output of antiquity. He differentiated between the pia and dura mater, accurately described the corpus callosum, ventricular system, pineal and pituitary, infundibuum and aqueductive silvius. He described higher cortical function and embraced the view that the brain controlled intelligence, fantasy, memory, and judgment. There was a long interlude and serious case of complacency after Galen. The Arabic and medieval period was one of great intellectual activity, and yet somnolence where originality of thought is concerned. Faith and teachings of antiquity was excessive, such that with the fall of the Roman Empire and up to the beginning of the 16th century, anatomy and the practice of surgery with rare exceptions lay dormant and chained to Galenic orthodoxy. The medical renaissance, like the original renaissance, began in the early 1400s and continued into the late 1600s. The acceleration of medical progress during the Renaissance depended on several factors including the invention of printing of particular importance, however, was the shift from theism and the belief that authority came from God to humanism and its belief that authority came from man. The more open attitudes of Renaissance humanism diminished church control of the teachings of the medical profession. Human dissection became more accepted and a better knowledge of the original writings of Galen developed. Advances in surgical techniques also occurred that would become important to the future field of neurosurgery. Valius was a Flemish born anatomist whose dissections of the human body helped to rectify the misconceptions made particularly by Galen, who for religious reasons have been able only to study animals. Vasalius identified the anatomical errors in Galen's work and challenged the academic world. During the Renaissance, the pace of scientific progress also accelerated outside of medicine. Nicholas Copernicus published his book on planetary motion in 1543, 1 month before Vesalius published his work on anatomy. The work done by Copernicus overturned the medieval belief that the earth lay at the center of the universe, and the work by Vesalius overturned the old authorities about the structure of the human body. In 1543, these two separate books fostered a change in understanding of the place of mankind within the macrocosmic structure of the universe and the microcosmic structure of the human body. But the field of neurosurgery still existed only in the imagination of Homo sapiens. An imagination that had evolved some 300,000 years previously with the advance from Homo erectus to Homo sapiens. It would not be until the 19th century that technological advances in cerebral localization theory, antiseptic techniques, and anesthesia would allow for neurosurgery to become a distinct profession and flourish. The pace of progress then sped up considerably. In 1861, Pierre Paul Broca heard of a patient named Louis Victor Lebourne, who had a 21 year progressive loss of speech and paralysis, but not a loss of comprehension or mental function. When Leborne died just a few days later, Broka performed an autopsy. He determined that, as predicted, Leborne had a lesion in the frontal lobe of the left hemisphere. The area of the brain important for speech production, now bearing the name of BOA, was determined to lie within the third convolution of the left frontal lobe, next to the lateral sulcus. Over the next 2 years, Broka went on to find autopsy evidence from 12 more cases in support of the localization of articulated language. John Hewlings Jackson began to give localization its modern theoretical form by working out many of his physiological principles through the study of large numbers of patients with focal motor seizures and other unilateral disorders. William Morton is credited for first using ether anesthesia in Boston in 1846. And in 1847, James Simpson used chloroform in Edinburgh. We Southerners know that despite what the folks in Boston say, Crawford Long in Georgia have been using ether for years before it was used in the famous ether dome of the MGH. The decade of the 1870s saw adoption of the germ theory. It was on the accident wards of the Glasgow Royal Infirmary that Joseph Lister would pioneer the transformation of surgical practice using the new germ theory of French chemist Louis Pasteur. In 1867, Lister published his first paper on the treatment of abscesses and compound fractures with carbolic acid dressings. William McEwen, a young surgeon in Glasgow, was well acquainted with the work of both Broka and Jackson and was directly tied to the antiseptic tradition of his fellow Glaswegian, Joseph Lister. In 1879, he combined these new technologies by performing two successful craniotomies, one for subdural hematoma and another for a meningioma. The first modern neurosurgical operations resulted from McEwen's firm conviction about the validity of antisepsis and localization. Thus, McEwen was the first practitioner of modern neurosurgery. But he was not really the first modern neurosurgeon in the sense of devoting the majority of his time and energy to the field. Only 2 years later in 1886, Victor Horsley was appointed surgeon to the National Hospital for the Paralyzed and Epileptic in Queen Square, London. The first neurosurgical appointment in the history of the world. Horsley can legitimately be called the first neurosurgeon. According to this strict definition, he was also the world's only neurosurgeon for many years. A distinct profession can be said to exist when there is an identifiable group of like-minded people who devote a large part of their time and energy to practicing the activity. Usually in accordance with some basic principles that are widely accepted. The rise of neurosurgery as a distinct profession can be indirectly attributed to William Halstead, who transformed surgical training through development of the academic residency system. His focus on the importance of research caused a second level of specialization among the Halstead residents, including Hugh Hampton-Young, who went into urology. William S. Baer into orthopedics, Joseph Colt Bloodgood into surgical pathology, and Harvey Cushing into neurosurgery. In the early 20th century, Harvey Cushing decided to make neurosurgery his life's work. Cushing's address on the special field of neurological surgery to the Academy of Medicine of Cleveland was the first overt appeal to the medical community for the recognition of neurosurgery as a distinct entity. It was given in 1904, 25 years after McEwan's first operations. Fishing moved to Boston in 1912, served a distinguished medical career in World War One. In 1919, delivered a paper on his improved brain tumor statistics to the American College of Surgeons. The eminent chairman William Mayo declared. Gentlemen, we have witnessed the birth of a new specialty, neurological surgery. The Society of Neurological Surgeons, the world's first neurosurgical society, was founded in 1920. It took Homo sapiens 290,000 years of natural selection to be able to tren the skulls of other Homo sapiens. And only 11,000 to develop modern neurosurgery replete with its accouterments. In the single century since Cushing introduced our specialty, the rapidity of additional advances has been mind-boggling. During the 20th century, the advances in our field have occurred at a rate never witnessed before in the history of humankind, and we have now become somewhat numbed to those progresses and expect them to develop and continue. So what does complacency have to do with the field of neurosurgery? Well, complacency often follows a period of success which we see in neurosurgery and it can quickly spread and reduce future uh success significantly. The volumes written about it there, uh, we see, we see complacency in nature, uh, we see it in business over and over again. Uh, we see it in in economics. uh, America's on track to go bankrupt. $1 trillion deficits are now the new normal and life as we know it is very close to ending, but, uh, we seem to be infected with this tragic stoicism and we don't even really think about it or talk about it. We see complacency in sports. Uh, my Atlanta Falcons got complacent in the 4th quarter of the 2017 Super Bowl, and they lost. Perhaps the 2016 presidential race was affected by complacency. Perhaps uh Hillary should have spent a little more time in Michigan, Pennsylvania, Wisconsin, where the deplorables were rather than assuming that she would prevail. Uh, entire nations have fallen prey to complacency. Um, we see it in war, calamitous decision by Napoleon to invade Russia in 1812 was likely the result of complacency, complacency that resulted from his army's repeated victories in Central Europe. Those victories led him to believe that Russia would surrender after a few battles, and he made no plans for a sustained campaign or occupation of Russia. The price for that complacency was 600,000 French lives. Hitler forgot his history. The ill-fated decision to invade the Soviet Union in 1941 underestimated Soviet military resilience and counted on the success of tactics that had been successful in previous campaigns, the invasion of Poland and the Battle of France. Confident of victory, the Germans didn't count on getting caught in a Russian winter, and as a result, the German offensive literally froze in the Soviet Union on December 5, 1941. We see it in medicine. Um, cardiac surgeons in the 70s, 80s, vast in remarkable success. They became fat, happy and complacent. They gave up the critical care management and the endovascular options for their patients and were about one drug or one stent away from unemployment. By the time they realized that they were a one trick pony, the cardiologists had dominated uh their field. The president of the Society of Thoracic Surgeons realized that CV surgeons should have entered the endovascular domain, but that was 2006. By that time they had lost that domain forever. As with Napoleon, Hitler, business cardiac surgery, complacency often follows a period of success. Andy Grove, who is a Hungarian born American businessman, engineer, author, and a pioneer in the semiconductor industry, I think said it very well. So both the knowledge of stroke, uh, and the field of neurosurgery had these very early and low laborious, uh, starts, but great progress in recent times. And this relatively recent success can set the stage for complacency. So let's look at the progress we've made during and since Doctor uh Drake's time. He belonged to what we have referred to retrospectively as the greatest generation, and, and he was, he was great, uh, he really was. I belong to a generation called the baby boomers, um, and many of the advances that have occurred in our field occurred before I was born, uh, and others as I was growing up and not terribly concerned about neurosurgery. Many of these advances would have been during Doctor Drake's career. Advances in imaging have been critical to the progress in neurosurgery. We're very dependent upon imaging, and this is a pneumoencephalogram, which for decades was the primary means of imaging the brain. It was introduced in 1919 by Walter Dandy, uh, the year before Drake was born and used extensively up until the late 1970s when it was, uh, replaced by more sophisticated and less invasive imaging techniques. I never saw a pneumoencephalgram. I barely missed it. Uh, when I was in medical school, radionuclide scans were in vogue, and the CT had recently been introduced into clinical practice. Moniz invented angiography in 1926 when Dr. Drake was 8 years old, but the images were not dramatically different than the ones I used when I first started my career, and we still did direct carotid punctures for some cases. The history of intracranial surgery for aneurysms is not a long one. The first direct operation on an intracranial aneurysm was performed by Norman Dott, who wrapped an aneurysm in 1933 when Charlie Drake was 13 years old, and the first obliterative clipping of an aneurysm was performed by Walter Dandy in 1938 when Drake was 18 years old. Neurosurgery improved dramatically when the operating microscope was introduced in the 1960s largely by Yasser Gill and Donaghy. During this time in the early 1960s, I was much more concerned about sports, birthday parties, and young girls. Um, meanwhile, while I was engaging in those activities, neurosurgeons were flocking to learn the art of microsurgery in the 60s and 70s before I had entered medical school. The first operations on the carotid artery were quite naturally ligation for trauma or hemorrhage. Surgical methods of treating carotid occlusive disease prior to 1951 were still like ganglion blocks, cervical sympaectomy, removal of thrombi, and reestablishment of blood flow, ligation and excision of the carotid bifurcation, and intracranial ligation of the carotid artery with silver clips, and these methods had little or no success. In two important articles in 1951 and 1954, C. Miller Fisher, neurologist at Mass General, defined carotid atherosclerosis and the relationship to cerebrovascular insufficiency, and he predicted that surgeons would one day develop carotid surgery as we know it. His prophecy was soon fulfilled. The first successful reconstruction of the carotid was performed by Correa in Buenos Aires in 1951 after he read Fisher's article. A 41 year old patient had recurring symptoms of left hemiparesis and aphasia. Angiography demonstrated severe stenosis, so they performed an end to end anastomosis between the left external and the uh distal internal carotid arteries. Patient made an uneventful recovery and died 23 years later from a myocardial infarction. Uh, they published the case in 1955, the year that I was born. The first successful carotid endarterectomy was performed by Michael Debaki in 1953, a 53-year-old bus driver had recurring episodes of right hemiparesis and dysphagia over a two-year period. Thromboendarterectomy was carried out, and that patient lived for 19 years with no further strokes, and died from complications of coronary artery disease in 1972, the year I graduated from high school. The from this experience, surgery on other extracranial vessels, the vertebral subclavian was developed and based on microsurgical techniques developed in the 60s, uh, Yasser Gill, Donaghy and Jacobson developed extracranial to intracranial bypass procedures for patients with clued carotids. In 1977, when I was halfway through medical school, a randomized trial was initiated to determine the efficacy of that very innovative procedure. I once asked George Tyndall, who was my chairman, why in the world he entered the field of neurosurgery at a time when there was so little that could be done for patients. His response was rather interesting. He, he didn't hesitate, and he said, because we knew things had to get better. And at the beginning of my career, George Tyndall could certainly rest assured that his field had indeed become better, but much was happened, much was to happen in the next few decades. In the initial years of my career, all aneurysms were treated 2 weeks after the subarachnoid hemorrhage. They were given strict bed rest. We gave huge doses of aminocaproic acid, uh, to prevent rebleeding, and if they survived 2 weeks, then we operated on them. Uh, we would occasionally still do carotid occlusions for anterior circulation aneurysms, the technique that my boss, George Tyndall had developed when he was a junior faculty member at Duke. Cavernous malformations were mysterious lesions, largely due to the fact we couldn't see them. They're they're invisible on angiography and very difficult to see on CT. There was no brain stem surgery, cavernous malformations of the brain stem were utter mysteries and completely undefined. Carotid and arterectomy was one of the most commonly performed operations, despite any objective evidence, it did any good for anybody at all. It just intuitively seemed to be the right thing to do. Radiosurgery was unrefined and rarely used, and embolization techniques were primitive, so most complex AVMs like this, we just operated on them without the benefit of preoperative uh embolization, uh, and, uh, we lost a lot of blood sometimes. During the early part of my residency, I spent 6 months at the Massachusetts General Hospital studying neurology under various masters, but including two of the greatest neurologists that ever lived, uh, Raymond Adams and C. Miller Fisher. Yes, the same one that described carotid endarterectomy. And there was considerable nihilism, uh, about the field of stroke at that time. I once heard C. Miller Fisher state that the primary benefit of stroke was to teach neuroanatomy. His famous quote was, you learn. Neuroanatomy, stroke by stroke, uh, and that's really what it was used for cause there wasn't much you could do for patients. Before the results of the bypass uh study was published, we operated on almost everyone with carotidoclusion did bypasses on them. The bypass study was finally published the year I finished my residency in 1985. And it was pretty clear at that point what the indications were for ECIC bypass. There were none. Every single category did better with medical therapy than they did with, with, with surgery. But the early part of my career were the golden years of microsurgery, when every cerebrovascular problem only had a surgical solution. Surgery was the only option and George Tyndall, God love him, indulged me and supported me in many of the crazy things we did. Sundt introduced the high flow bypass for aneurysms, and I had the honor and privilege of doing a fellowship with him at the Mayo Clinic and learned these techniques and we did some crazy things back then, all kinds of high flow bypasses. We did innovative bypasses like the petris to the supralinoid. Bypass, uh, what I learned is that in my hands if the patient tolerated this procedure, it meant they likely didn't need it in the first place anyway. uh, by the time I got finished with this, uh, they, they were either, um, they were either, uh, uh, you know, uh, not dependent upon oxygen or, um. They didn't need the the the the the operation. This is a young boy with moya Moya. I'll never forget his name's Elvis Stepp. um, he had no superficial temporal artery, no occipital artery and horrible moya moya. So we took his uh uh omentum out. We took a did a free transplant of his omentum. And, and as the most the gastro epiloic artery and vein to the facial uh artery and vein and laid it on his brain. I mean just purely human experimentation, and he had incredible revascularization of his brain. It was just almost miraculous, but we just made this stuff up as we were going along. Early in my career, we did lots of deep hypothermic circulatory arrest cases in this young woman from Mississippi who presented with a Weber syndrome from a compression of her brain stem. Here you can see um uh under the temporal lobe, uh here is uh the patient's now on bypass and you can see the heart stopping and the aneurysm sac deflating. We put a temporary clip on the basillar in case the aneurysm opens so air wouldn't get in the system because with the heart not beating. For 45 minutes, uh, we want to make sure that air didn't get in the system. Here you can see the heart stopped, uh, the aneurysms completely collapsed and during about 40 minutes of complete circulatory arrest with the patient 18 °C, uh, we can, uh, leisurely, uh, somewhat leisurely, uh, reconstruct this aneurysm, uh, with a series of clips. Uh, and here you see the, the final result, and this is actually an intraoperative angiogram done with the patient on bypass, but it was enough to let us see that the superior cerebellar and posterior cerebral arteries were open. This is um the way we did embolectomies before the Mr. Clean trial, and the others that demonstrated the benefits of mechanical thrombectomy. We just take the patient to the operating room. Open up to Sylvia and Fisher, um. Here's the embolus. In the middle cerebral artery for atrial fibrillation. And we sewed the vessel back up, um, you know, um, and you guys complain about having to take call for thrombectomies at night. Uh, but it was a fun operation to do. Uh, they didn't, they didn't all do very well by the time we got that done, but, um, it was, it was fun. Uh, and during my career and, and what would have been the latter part of Doctor Drake's career, uh, the progress has only accelerated. I, I think one of the most important things has been subspecialization, which has led to focus and more rapid advances in all of our subspecialties. The quality and rapidity of CT imaging. Improved dramatically during the early part of my career and in the 80s, MRI was introduced. I mean, you know, it's hard to believe that we practiced without MRI uh but it, it provided imaging that was previously unimaginable and at this point in my career, I was chin deep in vascular challenges, but this opened up an entire new era for us. We can now see things like cavernous malformations that on CT we didn't know what these were but with MRI they became it was almost pathonemonic. Um, we learned that we could safely remove these from regions previously thought to be completely forbidden territory, the thalamus, the brain stem, spinal cord, and so it opened up new, uh, opportunities for us. FMRI and PET scanning allows to see the brain in action and DTI imaging helps as a plan approaches to avoid the high priced real estate. And, and do them safely. angiography has improved dramatically, but today, sometimes we don't even do angiography to make clinical decisions. We'll take patients to the operating room based upon CT angiography. Technology and metallurgy improve the closing pressure of aneurysm clips and provide additional angles and fenestrations and MR compatibility. The calcium. Antagonist nimodipin was introduced during my career and reduced the risk of delayed cerebral ischemia and uh delayed surgery after subarachnoid hemorrhage was completely abandoned in early, uh, in, in favor of early surgery. And then of course the development of the GDC coil in 1990 provided an alternative approach that avoided the hazards of, of open surgery. Uh, this is a, uh, a video of one of the first GDCs ever placed at Emory. He did it up embolizing into the middle cerebral artery, and uh we had a visiting professor, I'll never forget it was Bill Friedman. I'll never forget this, and, and I got a call the beginning of his lecture and my endovascular colleague said, oh my God, Dan, we got this horrible problem. So I ran over and did this case. And was back before Bill had finished his lecture. He's a slow talker, but this is the first GDC coil, uh, at Emory, and after this, I thought, oh hell, endovascular therapy, hell, that's not gonna be any challenge to what we do. I, I thought endovascular therapy was, uh, uh, probably going to be a, a, a fad, kind of like, uh, pet rocks and the hula hoop, uh, uh, boy, was I wrong. Don't let me down. So things changed, um, these and other events eroded the microsurgical case volume and threatened the future of open vascular neurosurgery and transformed it into a multimodal specialty with different skill sets, distinct training programs, and the possibility of competing interests of individual practitioners. So, what about today? What is the role of microsurgery today? Well, I, I think it's very bright. I, I, I think there are many indications and a lot of equipoise. Um, neurosurgeons still treat in cerebral hemorrhage, uh, from all types of pathologies, not just vascular malformations, but there may even be a role for spontaneous hemorrhage from hypertension. We have a lot of options as neurosurgeons, uh, for ischemic stroke, and we play a role in all the, the treatments of subarachnoid hemorrhage, including surgery, and I'll talk about that. Now, ICH is an intuitively surgical disorder. If you got a clot in your brain, it's gotta be good to get it out. But we've had a very difficult time proving that despite a number of randomized trials. So at Emory, we developed and executed the enriched trial, uh, to try to determine if there really is a role for a paravasicular minimally invasive surgery for spontaneous intracerebral hemorrhage. This multi-center trial was established um to randomize 300 patients. Um, and a few weeks ago, we randomized our 300 patients. So the study is done, and with a minimum 6-month follow-up of those patients and data analysis, we hope we'll actually have an answer in about 7 months, uh, and see if there, if there is a role. I think there is a major role for surgery in the treatment of AVMs. In fact, I think it is the single most important treatment uh paradigm we have. The problem with the other options is embolization alone rarely cures an AVM. Uh, we certainly know that from uh the Aruba trial where it was the primary modality used and the results of that trial were were terrible. Um, and evidence is now coming out that more people are, are, are coming into the hospital with ruptured AVMs because of the findings of the Ruba trial. Despite those AVMs in that trial being grade 1 and grade 2 lesions, virtually none of them were treated with microsurgical treatment, which uh has an extraordinarily low morbidity and mortality. So I think there is a bright role for surgery with AVMs. Dural fistulas, on the other hand, have become largely and appropriately an endovascular disease. Um, the pathology is that site where the actual fistula occurs. It is a very simple pathology, despite how, how horrible the angiograms look, and it doesn't matter whether you interrupt that with the surgical clip. Coagulate it or fill it with coils or or onyx, and it is far safer and far better to treat the majority of these with endovascular therapy and using transarterial and trans venous combinations, most of them can be treated in that manner, but there does remain a role for some selected ones this. fistula of the sinoparietal sinus really didn't have any endovascular option to get to it. And the surgical treatment is simple. You literally coagulate the vein. There's no nitis to remove you coagulate the vein right at uh the fistula and, and it, it's, it's, it's done. Cavernous malformations, the only reasonable treatment option is surgery. Uh, radiosurgery has been tried, uh, has never been shown to get rid of cavernous malformations. It, it is known to cause them, uh, in patients that are pres uh have a predilection for them. And so, uh, we now knowing, uh, and having defined safe entry zones, uh, here's a malformation being removed from the dorsal, uh, midbrain. Uh, uh, through a lateral supra cerebellar infratentorial approach. So even in areas where early in my career, we were truly forbidden territories, we routinely operate in those areas and surgery has a, a, a major role still. Management of spinal AVMs depends on the type, but primary uh treatments, in my opinion, I, and I, I admit I have a surgical bias, but I think, um, Uh, play a big role. The most common, the dural fistula, is associated with devastating natural history, and I have a very strong surgical bias for treating these. This is the pathology. The pathology is, is literally right there at F. This is the artery, that's, that's the, that's the pathology. And so the treatment. It is simple and durable. So there's the fistula, right there, you coagulate it and you divide it. The problem with endovascular therapy is if you push the emballos it into the venous system, you exacerbate the venous hypertension, and if it's short of it, it, it recurs, and so we treat most of ours surgically. For the more complex type 2 or glomus lesions, surgery oftentimes is the only treatment. Um, this is a, a young boy who presented with the Brown-Soca syndrome from a hemorrhage from this horrible AVM. You can see it's got an aneurysm in it. It's fed by the anterior spinal artery. Here's the AP view. We literally did a midline myelotomy, went all the way through his spinal cord to the anterior spinal artery, and, and resected the AVM from a purely dorsal approach. And here's the postoperative angiogram. And To demonstrate not my surgical ability, but the fact that kids make you look really good because you can do that kind of stuff on them and get away with it. This is that little boy at his postoperative visit. And Pretty remarkably, about a decade and a half later, I was in my office, and this kid stopped by on his way to Vanderbilt University to thank me, and it was the same kid, um, about 15 years later, who had never had any recurrence of that spinal ABM. So I think it demonstrates the durability of surgical treatment. For cavernous malformations of the spinal cord, there is no other option. Surgery is the option and will remain the option for the foreseeable future. Um, and very much like brain stem cavernous malformations. We have learned that we can get excellent results with these, that if we're just careful, these are very well circumscribed from the surrounding um uh spinal cord, they're much easier to deal with than arteriovenous malformations. They can be removed in a piecemeal fashion and you can eliminate on a permanent basis, the risk of future hemorrhage. The options for treating carotid stenosis include uh medical, surgical, and endovascular options. Uh, carotid endarterectomy is now one of the most studied procedures we do. There is overwhelming evidence that it is superior to medical therapy for symptomatic patients with high grade stenosis. You only have to do 6 carotid endarterectomies to save 1 patient from having a stroke. So it's a pretty low bar. Now, if the patient has a lower grade stenosis, You have to do 15 of them to save one patient from a stroke. And indeed, there is also a role for asymptomatic patients. But remember, you have to do 67 carotid endarterectomies with no complications to save one patient from having stroke. So you better be very careful when you select your asymptomatic patients. Well, just about the time that we demonstrate efficacy, along comes angioplasty and stenting, and You know, I think the Crest trial was very, very important in that it proved that both of these treatments are safe and they're efficacious. There were more strokes in the stenting group, but there were more MIs in the surgical group. I would point out. And again, this is my surgical bias, that the MIs were largely asymptomatic enzyme elevations and the strokes were strokes. So I think surgery actually won this contest, but the point is, I think there's still a strong argument for surgery for carotid disease. Now, when the carotid is occluded, options are medical therapy, ECIC bypass, and angioplasty and stenting, the latter having been demonstrated by the Sampras trial to be largely inefficacious. So bypass is the intuitive option, but it, it already failed, uh, an initial bypass trial. So along comes the the cost study, which we were part of. Finally, we have the ability to identify patients who actually have hemodynamic insufficiency using PET scanning and oxygen extraction fraction. But after years of randomized patients, The study failed to show benefit, but it wasn't because of lack of efficacy, it's because of the improvement in the medical management of stroke from the beginning to the end of the study was so great, we would never be able to randomize enough patients to show the little benefit that surgery might have. So, what are the indications for bypass today? Well, maybe a few. Um, I think the few include Moya Moya disease for which we do a lot of bypasses still. There are selected patients with hemodynamic insufficiency that have failed medical therapy that our neurologists sent for bypass, and then certainly for complex aneurysms. So, Let's go to finally to the most controversial subject. Uh, what is the current role of microsurgery in the treatment of aneurysms? Well, again, I will admit my surgical bias, but I think there is equipoise for many aneurysms, a state of genuine uncertainty regarding the comparative therapeutic merits of each of the options available. So, let's look at the data. Um, there have been 4 randomized prospective trials of ruptured saccular aneurysms. ISA demonstrated endovascular superiority at 1 year, but not at 5 years, and not at 10 years, except for deaths. They changed the, the endpoint, uh, at the end. The Brad trial showed no difference at any time point for secular aneurysms. The finished study showed no difference, and the least study from China showed no difference. Uh, a matched control study from Canada showed actually the clipping was superior. As my dear friend Robert Harbaugh once said, this is pretty shaky evidence to justify a revolution in the treatment of aneurysms, but indeed, there was a revolution in the treatment of aneurysms, no question about it. Well, what about endovascular advances? I mean, since those trials were done, we now have balloon remodeling, stent coiling, flow diversion. The problem, and these are wonderful tools and we welcome them, but the problem is when a patient has a subarachnoid hemorrhage, there's a relative contraindication to these options because of the need for dual antiplatelet therapy. I think we'll get around that somehow with technology, but right now it's, it's a problem. Uh, and endovascular therapy is associated with higher recurrence rate, higher rebleeding rate, less ability to eliminate mass effect, and continued unsuitability for some aneurysms. Now, for some aneurysms, there is no longer equipoise. Uh, symptomatic, cavernous segment aneurysms, hands down, flow diversion is the treatment of choice compared to the crazy things we used to do with bypasses and occlusion of the carotid. And so there is no debate any longer. But I would argue that although endovascular adjuncts are a very welcome addition to our armamentarium, there are many patients who are not good candidates for endovascular therapies, and there are many aneurysms that are not. Good candidates for uh uh uh endovascular techniques and for which there's equipoise. For aneurysms associated with the life or health threatening hemorrhage, it is completely illogical not to clip it while you're there taking the clot out. Why would you put the patient to two procedures, one of them being less durable, you fix both of them at the same time. Some aneurysms that are large and associated with the mass effect are better managed with microsurgical treatments. This is the last circulatory arrest case that I did. Uh, we didn't have any endovascular options for this aneurysm, so the patient, uh, uh, went, uh, under a cardiac bypass, and this is the result we got. I, I, I just don't think we could have done that with an endovascular, uh, device, and this is, this has never recurred. This was several years ago. This is a patient with a large pia aneurysm causing massive compression of the brain stem, and you can see that PICA is coming right out of the uh neck of the aneurysm. So, we, at the time of surgery, take advantage of the fact that the two pikas are right next to each other. We do a pika, pika bypass side to side, and then we trap the vertebral artery, and you can see the big mass underneath the brain stem. We open it up and decompress the brain stem, and there's the ICG showing the bypass filling. Some aneurysms are too small for endovascular therapy. This mid basilar aneurysm that ruptured, we, we had to treat it by clipping, there wasn't any coil small enough to get uh into it. The patient had a subarachnoid hemorrhage, so we didn't wanna put a flow diverter in. For aneurysms with highly complex configurations and very wide necks, we have some wonderful new tools. They're called aneurysm clips, and they work extremely well for those complex and wide-necked aneurysms. Thrombotic aneurysms are notoriously resistant to endovascular resolution as the coils just migrate into the thrombus, and the mass effect isn't reliably eliminated. Here's a posterior cerebral aneurysm, the dots outlining the true size of the, of the mass. And here you can see under the left temporal lobe, you can see the P1, the P2, and the aneurysm compressing the brain stem. So, through a subtemporal approach, here you can see the, the, there's the P2 to the PO connecting it to the carotid. So we separate the um That's the distal, uh, I mean so the proximal posterior cerebral artery. There's the post you're communicating, we separate the distal. Posterior cerebral, the P2. Open the aneurysm, do an aneurysmorphe. Which immediately eliminates the mass effect on the brain stem, which was the, the problem the patient presented with. Um, and also softens the uh sack so that we can reconstruct it with, uh, uh, with clips. Here's the thrombus being taken out. And fennistra clips used to reconstruct the posterior cerebral artery with the fenestration, um, reconstructing the lumen of the posterior cerebral artery. One of the most common indications for surgery are endovascular failures. This is a 60, I'm sorry, 36 year old man. Who was presented to an outside hospital in 2015 and underwent coiling of this somewhat large uh carotid M1 bifurcation aneurysm, and he was lost to follow up and came back to us four years later and you can see that he's had a new hemorrhage and his aneurysm has grown dramatically. Um, only a small portion of the aneurysms filling. You can see the dots outline the actual size, the lenticular stripes stretched around it. There was marked stenosis of the middle cerebral, uh, proximal, uh, uh, beyond the neck. So the plan was to insert a radial artery here. Occlude the vessel distal to the aneurysm to create a blind sac, so that the lenticulous triads would fill through the bypass, but the blind sac would occlude. Here's the six-week postoperative angiogram showing the lenticular strides filling and the aneurysm completely uh thrombosis. And uh this gentleman made an excellent recovery and is very grateful for the permanent solution that we provided him, um. Fusiform blister aneurysms present challenges for both endovascular and microsurgical techniques. This is a young boy from Africa who hemorrhaged from this large fusiform aneurysm. So the plan was to do a bypass to the, this branch using the superficial temporal artery and then trap the aneurysm and, and, and open it up and resect it. So here's the intraoperative angiogram. Uh, you can see there's a, a hole where that artery used to be, but when we inject the external carotid, you can see that it fills that hole, and so it was a, uh, a surgical uh uh option for him. Now, in this patient's home country of South America, She was recommended she undergo a craniotomy for clipping of her middle cerebral aneurysm, and then endovascular treatment of her basal or artery aneurysm. Totally, completely illogical. These two aneurysms are about 1 inch apart from each other. They both are exposed to exactly the same procedure. If you're operating on the patient, for God's sake, why wouldn't you do both of them at the same time? And here's the intraoperative angiogram showing that we did that. And finally, you know, these have been examples where I think surgery is a better option, but endovascular therapy and surgical therapies are not mutually exclusive. Uh, they can be combined in selected cases. This is a young man who has this unusual aneurysm, probably an old dissection where there's an artery coming right out of the dome of the aneurysm. There isn't a surgical option and, and an endovascular option we thought would include that artery. So we took the patient to surgery. Put a temporary clip on that artery that's coming out of the aneurysm. And I wanted to identify the branch on the surface that corresponded to it. And I knew it was one of these two, but wasn't sure which one. So with the temporary clip, we did an ICG and you can see that one of them isn't filling. When I take the temporary clip off, it fluoresces. So that's the one I want to revascularize. I plug in a bypass. We take the patient, you can see I've occluded that artery. You can see the flow diverter being put in, this was done by Jacques Dion. Almost immediately, the aneurysm is going away and the external carotid shows that uh I'm filling that branch through my bypass. So, with all this success. What do we have to fear? Well, This rapid success in neurosurgery, starting with trephination and coming all the way to these wonderful things we can do after thousands of years of development, sets the stage for the same complacency that plagued the pre-Renaissance physicians, Napoleon, cardiac surgeons. We've witnessed. Placency on our field in the past, having been at the leading edge of developing surgical treatments for peripheral nerve surgery, we've largely lost that to plastic and orthopedic surgeons. Uh, neurosurgeons developed carotid endarterectomy, and today we do about 7% of them. Uh, pain surgery was pioneered by William Sweet. We've largely lost that discipline to a variety of other specialties spine surgery, endovascular therapies, and neurocritical care are areas where neurosurgeons make great contributions, but we almost lost had it not been for the collaboration and for the rather heroic efforts of some of our specialist leaders. In 1899, Charles Duelel, who was the commissioner of patents, allegedly recommended to President William McKinley that the United States Patent Office be closed because everything that can be invented has been invented. Now these are probably not really the words of William of uh of of um Charles Duel, but they're probably apocryphal. But for young neurosurgeons entering the field of neurosurgery today that has witnessed the development of microsurgical techniques, endovascular therapies, remarkable advances in neuroimaging, the growth of molecular biology, mapping the human genome, stem cell therapy, they may believe that. Everything that could be developed in our specialty indeed has been developed, but that premise is as wrong today as it was when Mr. Duel allegedly made his comment to President McKinley. There are more than 1000 neurological diseases affecting more than a billion people worldwide. So there is much work left to do. American medicine has done a terrific job increasing the quantity of life. Now we're faced with the challenge of improving the quality of that prolonged life. You know, we all hope to live long, long lives, but none of us want to live to be 100 if it means that we can't move, we suffer with pain, we're severely disabled or. We've lost the memories we spent a lifetime creating. Indeed there are many ongoing challenges facing us, and those challenges must be addressed by all of our physicians, physicians, scientists, and our basic sciences within our departments and centers in cerebrovascular disease alone, there are many remaining challenges. I've talked with some of you today about them. We need strategies to take advantage of the reversal penumbra with pharmacologic extensions so we can do thrombectomies later. We need advances in molecular profiling of vascular pathology. We need prospective randomized trials comparing our current therapeutic options. Um, we need to determine if minimally invasive surgical techniques are beneficial and intracerebral hemorrhage. And we must explore the amazing opportunity to merge endovascular therapies with brain machine interfacing like the synchron uh device, and we need to develop medical treatments for challenging cerebrovascular disorders such as untreatable aneurysms or cavernous malformations not amenable to surgery. In many conditions. That were never considered neurosurgical problems are now known to be brain diseases with potential neurosurgical solutions, many of which will be addressed by our functional colleagues, movement disorders. Psychiatric disorders, these are brain problems that we can fix, pain. Eating disorders. Drug addiction. There is already success in some places doing deep brain stimulation or neuromodulation for addiction, uh, memory loss, and of course the holy grail to be able to repair the diseased or the injured brain. What are our limitations? We are only limited by our imaginations. By our functional imaging. By our financial resources. And complacency. Charlie Drake He was certain they could do better in his time. He was not complacent, nor timid. He was brutally honest, and he tackled the most challenging of all the issues facing vascular neurosurgery at the time, basal aneurysms. He was painfully honest. He reported not only his successes, as Mike said, but painfully described his failures. He described the perforating vessels, the thalamal perforators that he occluded and recognized that's why his patients died or did things worse than dying. He highlighted the importance of these that he had inadvertently clipped and taught the rest of us how to avoid them. Throughout history, there have been a lot of really smart people who didn't see it coming, like the Decca recording executive who missed the Beatles. Well, I think neurosurgeons, uh, have seen it coming, and we have embraced new technologies like endovascular therapies, stem cell therapies, making diseases, surgical diseases. I have extreme confidence in the generation to whom our as baby boomers are leaving our chosen specialty. Vascular neurosurgery is in the most competent hands, and our problems will lead to solutions and what was thought to be impossible will become routine, but the key I believe is research which our specialty has embraced much more than most surgical specialties. We must continue the basic research that has advanced our specialty, and the clinical research that translates that to human disease, but we also need technology research, particularly in big data and artificial intelligence, and for God's sake, don't become complacent. Thank you. Questions? Yeah Doctor, thank you so much for your presentation. It was, uh, it's really humbling to see like everything that has, uh, you know, has going on in the field of cerevascular surgery. Um, I have a question for you. Of course, you know, I have a uh an endovascular bias, but the question to you is when you show like those surgeries, for example, I mean, some of those surgeries are pretty complex, right? And I see that most of the cerevascular surgeons are actually being hybrid trained, so they do potentially both endovascular and open surgery. Now, do you foresee that in the future? You know, depending on the complexity of those do you think someone, I mean, all those younger neurosurgeons, would they be competent to do, you know, for example, basal tip giant aneurysm, for example, as you showed, or you feel like that is something that it is potentially, um, you know, it's gonna be more and more difficult to have someone that will be competent in doing that looking like, I don't know, 1015, 20 years from now. Yeah, yeah, it's a problem. I, I don't, you know, I, I mean, there's nothing, you know. I, I don't, I, I don't wanna try to, you know, show these cases to, to try to convince you I'm a virtuoso. I mean, I think anybody can learn to do these things if you commit yourself to it. But the only way you get to do those things is by doing it over and over and over again. And I lived, as I said, through the, you know, the, the best times of cerebrovascular surgery. I mean, we, we, we didn't have any options and so, so you do it over and over and over again. And, and, you know, part of the decision making about what's best for an individual patient is, is not just You know, what options are available, but what's available for that patient and what the individual practitioner is best at. And, and sure, I, I, you know, I, again, I, I, I joke that I have a surgical bias. I, I mean, I do, but I'm honest about it. I have an incredibly good relationship with my colleagues, and we never argue, ever, never have had an argument. We, we push each other really more than, than, you know, than we, we joke around, but, but we, we push each other to do things. I said you, uh, you know, I can't, oh no, no, I've seen you do this, you're gonna do a better job than we're gonna do in asking. No, no, no, you don't we, so we, we have a lot of that. I think, I do think that to train the next generation of cerebrovascular surgeons, I think, I think it's gonna be done in a very few places. I think you need high volume, obviously, you don't have high volume, you don't have the cases to do it. You need a collegial relationship with your endovascular colleagues, you need a skull-based laboratory, which we have, you need a microvascular laboratory, which are easy to do this day and age, you can get cheap microsos. And I believe you need some faculty, not all, with a surgical bias. Uh, if you don't have that, you need somebody like me that at every M&M conferences, what the hell were you thinking? Patient has a blister aneurysm with the subarachnoid hemorrhage, and you, you put a pipeline that was in our M&Ms is that what I said? It's the most illogical thing why would you put it, why would you put somebody to do an Ilate therapy with a subarachnoid hemorrhage. Well, I, you know, I know it's a reasonable option, but I wanna play the devil's advocate. I wanna be that guy that you guys hate, that's, you know, points out that, you know, there's a durable time-honored way to treat these things, but you have to roll your sleeves up and take them to surgery. So, you know, I think the things that I'm showing you are not gonna exist in the future. Part of the reason is because Let's just take aneurysms. In in health care, in in United States health care, in the cost, and the importance, it is a rounding error. I mean, I hate to say it this way, but if every single patient with a subarachal hemorrhage died, Nobody would notice except the families and and those of us that care for those patients. It's not, it's not. You know, it's not um arthritis, it's not hypertension, it's not something that is important. So the healthcare systems, frankly, aren't gonna care whether we clip or coil aneurysms. That's something that we can, you know, talk about, um, but Yeah, I think you're right. I mean, it's, it's headed that way and But I think for the foreseeable future, my point is I think that microsurgery will still play a major role in, in the overall management of cerebrovascular disease. Um, you know, from a residency training standpoint, are y'all starting to integrate the, you know, the skull-based laboratory micro neurosurgery and kind of really build a curriculum to make sure that everyone Yeah, completing that. Yeah, yeah, we are. So all of our residents rotate on endovascular therapies. Uh, we, um, uh, thanks largely to your former mentor Gustavo Pradilla, Gustavo has built a beautiful skull-based laboratory, uh, at Grady Hospital, which is one of our multiple hospitals where residents train. It is, it is an excellent resource and up until last year, it was just something that was there that you could use if you wanted. Now we're actually implementing it as a, as a rotation uh to actually have every resident spend some time there cause, you know, I mean, cerebrovascular surgery is, is just microsurgery. That, that's all it is. Uh, you know, we do different things, but it's microsurgery, and I am of the firm belief that all neurosurgeons are better surgeons by learning microsurgical techniques. If you're a spine surgeon, You are a better spine surgeon than the average orthopedic surgeon. I'm nothing against orthic surgeon, don't get me wrong, I've got colleagues who are great, but just having learned microsurgical techniques and how to deal with tissue under a microscope gives you a leg up. If you're a pediatric neurosurgeon, a tumor surgeon, that micro microsurgical Training makes you a better surgeon and I, I was talking, you know, to some of the endovascular folks today about the importance of if you're a non-neurosurgical endovascular person, the beauty and the importance of going to the operating room, seeing the brain in three dimensions. I mean, we learned so much from each other and um that's been one of the rich parts about our department is we have neurologists, radiologists. Uh, all the neurointensivists are in our department, all the endovascular people, regardless of what union card they carry, they're in the department of neurosurgery, and we, it creates an environment that is so much more rich for learning than if we're just a bunch of neurosurgeons, you know, uh, uh, knuckle draggers, you know, with, uh, writing our orders with crayons, you know, trying to, you know, tell each other how wonderful we are. Um, it, it, it's, uh, that environment is much more rich for learning. Um, I've got a question. Any, I wrote a paper, I think it was published in 1990 on temporary arterial occlusion. Uh, an aneurysm surgery. Are there any advances beyond propofol and thiopental in terms of brain protection during the period of No, not, not, not anything of any importance. I mean, you know, we've, we've, since you wrote that paper, we've learned maybe a little bit more about the tolerances, the amount of time, uh, we've got better monitoring that allows us to predict ischemia, um, but, um, no, I mean, that was one of the things I alluded to. I, I, we really do need pharmacologic. Um, uh, options for, for prolonging the, the penumbra, uh, you know, for giving us that time for, for temporary occlusion during surgery, for patients with ischemic stroke, you know, that, that are not at a, at a comprehensive stroke center or thrombectomy ready center. We, we, it, it, it, it seems so imminent. I mean, you know, the, the, the NMDA receptors, you know, work that was done by Choi and others, you know, back in the 80s, you know, looks so promising and it just, none of it ever worked. It seems like something that somebody's gonna figure out sometime, how we can prolong, uh, that ischemic, protect the brain, you know, better. But yeah, I use propofol still and induced hypertension probably is better than anything when you are temporarily clipping something. uh I've also question, can I ask one more while I got the mic. You can do whatever you want. You're the boss. That's what you told me anyway. Um, in my 28 years at UCSF and you've seen, I, I think you've seen this as well, even at the barrel, um, there's been a slight change in um the surgical management of grade 3 B if you want, and above ABMs because of the morbidity, and I saw Michael back off big time. Uh, he really wouldn't operate on anything, um, that was, um, above a grade 2 if it hadn't ruptured, if it was particularly if it was close to eloquence. Um, so therefore we used a lot of, you know, radiosurgery, not embolization before treatment and what's your, we didn't we shied away completely from treating these big low bar AVMs with anything because nothing seemed to work. you have common sense? Well, we've learned, we've learned that. Counterintuitively, big AVMs are less likely to bleed than small ones. I mean, if you measure the pressure in AVMs, we've done it, others have done it, pressure is higher in a small AVM. And if you think about it, it makes sense. If you got a big AVM, you, you know, you've got more space to, you know, dissipate the, the pressure and, uh, and so, you know, we use that to our advantage to, not to say that grade 4 and grade 5 AVMs are something I would want to have or one of my family members have. But we use that to our advantage to, to give patients some, some security by saying, good news is, the bad news is we really can't treat your AVM safely. The good news is, this is much, much less likely to bleed than, you know, the small AVM that I'm operating on tomorrow, and you can reassure patients, there's no, there's no benefit of taking patients hope away. And telling them, you, you know, you got a horrible disease, there's nothing I can do for you. That, that doesn't do anybody any good. So I use that uh that information uh to try to reassure patients that I believe I can't provide any uh reasonable treatment for. To make them believe that they have a, a, a, a better natural history. But, uh, Yeah, I, I agree. I, I think I would radiosurgery is ideal for, it's ideal for small AVMs. They're deep in the brain that we can't get to safely. That, it's great for that. But for, you know, AVMs that are accessible, surgery has a much, uh, a huge advantage. You know, when you add up the, the risk of hemorrhage over the 3 to 4 years you're waiting for the radiosurgery to work, you add to that the, the high likelihood it's not gonna work. You know, I mean, even with a small ABM it's maybe 80%, uh, you know, and then you add to that the 2 to 3% risk of radiation injury for grade 12 AVMs, you can operate on them with a dramatically lower risk than that, that combined risk. So I, I, I, it troubles me to see, you know, small accessible AVMs treated with radiosurgery, um. Without getting uh An opinion. Yeah, our, our philosophy was grade 12 ruptured surgery. Um, the grade 3s, 4s were very difficult to manage, but multidisciplinary. Yeah, you know, there's, there's the, the, the problem with the Spitzler Martin grading system is just too complicated. So, you know, what I use is what's called the Barrow Eastwood uh grading system. Clint Eastwood and I developed it together. Only there are only 3 types of AVMs the good, the bad, and the ugly and, and it's interesting that Robert Spitzler, my dear dear friend who I've, I've abused most of his life, actually came around to that and, and one of, you know, he's published his grading system, you know, so many times that um. He tweaks it so he can get another publication out of it, but he actually, in his last, his last publication, he grouped, he grouped the the the the threes and the 4s and the fives together. So basically, he came up with the good, the bad, and the ugly. He called them A, B, and C or something like that, but anyway, Barrow Eastwood, that's the way to go. Um, any other questions? Well, Dan, I think that was a really a captivating presentation. We really enjoyed it. I think I can say that for the group and uh for those who are watching by Zoom, I hope they felt the same way. But let's uh take a pause. I think we have some refreshments outside for everybody and uh please come up and introduce yourself to Doctor Barrow. Thank you. Thanks. Thanks. Thanks everyone. Just the, just the, the, yeah. You know, I didn't know audience would have.
