Latest / European Society for Vascular Surgery / Aortic Dissections – The Asian Perspective with P. Robless

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Aortic Dissections – The Asian Perspective with P. Robless · European Society for Vascular Surgery

• 0:00
  Welcome to the ESVS podcast. I'm Laurence Bertrand
• 0:02
  and today we have a special episode focused on
• 0:05
  the Asian perspective of aortic dissections.
• 0:07
  I'm delighted to be joined by Dr. Peter Robless
• 0:10
  in Singapore to explore this topic. Dr. Robless
• 0:12
  has founded the vascular surgery department at
• 0:14
  the National University Hospital in Singapore
• 0:16
  and has been a leading figure in the world of
• 0:18
  vascular care in Southeast Asia. He has served
• 0:20
  as president of the Asian Society for Vascular
• 0:22
  Surgery, ASVS, in 2016. He's also on the organizing
• 0:26
  committee for the annual Aortic Asia Symposium.
• 0:29
  Dr. Robles, thank you very much for joining us
• 0:31
  today. Thank you very much, Laurence. I'm very
• 0:33
  pleased and excited to be on your podcast. I'm
• 0:36
  so glad you made the time to be with us here
• 0:38
  today. To begin, I'd love to hear a little bit
• 0:40
  about your personal journey. What drew you into
• 0:43
  vascular surgery and what was it like setting
• 0:45
  up vascular surgery department at NUH in Singapore?
• 0:49
  Yeah, so that was sometime maybe 20 years ago.
• 0:51
  I finished my training in the UK and I went to
• 0:55
  Australia to... learn some endovascular surgery.
• 0:59
  And in between, I took the European Board of
• 1:03
  Vascular Surgery exam in Innsbruck. And on my
• 1:06
  way out, I stopped in Singapore and looked at
• 1:08
  and I had a visit to the hospital. And just by
• 1:11
  accident, they were looking for a vascular surgeon
• 1:13
  to join the cardiac department to set up a new
• 1:17
  department of vascular surgery, if you like.
• 1:19
  So things, you know, got going and I ended up
• 1:23
  working there as my first job after finishing
• 1:25
  my training. It was a kind of a stab in the dark.
• 1:29
  I had no idea what to expect, but the cardiac
• 1:32
  surgeons were very nice and helped me set up.
• 1:35
  They were happy that all the vascular emergencies
• 1:37
  could be dealt with by somebody and not them.
• 1:40
  But it was a very good synergy because they saw
• 1:43
  a lot of aortic work, which came through the
• 1:46
  hospital to them and not to general surgery.
• 1:50
  So it was a very busy first three years. I don't
• 1:52
  think I went home very much in the first three
• 1:54
  years. So looking back, how do you feel the field
• 1:58
  of vascular surgery has evolved in Singapore
• 2:00
  and in the region? And from your experience,
• 2:03
  have the clinical needs changed as well in the
• 2:04
  past 20 years? Well, looking back over the last
• 2:07
  two decades, when I joined the hospital, there
• 2:10
  were four vascular surgeons on the island of
• 2:13
  about 5 million people. And now we have 44 vascular
• 2:17
  surgeons. And we're all very busy. I asked my
• 2:21
  professor at the time in St. Mary's in London,
• 2:24
  what would it be like to go to a new place where
• 2:27
  there was no vascular service? Would you find
• 2:29
  any work and so on? And she said to me, Professor
• 2:32
  Mansfield, that is, that, you know, if you do
• 2:35
  that, the work will just come. And so she was
• 2:37
  right. I had the biggest challenge was to organize
• 2:40
  the service, to build a vascular lab. to do a
• 2:44
  service for aortic emergencies, lower limb, and
• 2:48
  then limb salvage. So that's taken about a decade
• 2:52
  or so to evolve. So now our biggest challenges
• 2:54
  are aortic emergencies and also the tsunami of
• 2:58
  diabetic limb salvage. That consumes a lot of
• 3:02
  resources. So let's move the focus to today's
• 3:07
  discussion. I'd like to talk about aortic dissections
• 3:10
  in Asia, as announced. I'd like to start by looking
• 3:12
  at some of the epidemiology. In European population
• 3:15
  -based studies, incidence reports range from
• 3:18
  about 2 .5 in Germany to 7 .2 in the Swedish
• 3:21
  sets per 100 ,000 person -years. Depending on
• 3:25
  the country and case rupture methods, while available
• 3:28
  population data in Asia is not as abundant as
• 3:32
  in Europe, there are some Japanese. Korean and
• 3:34
  urban Chinese data sets that suggest similar
• 3:36
  regional variation from 2 .7 in a Chinese set
• 3:40
  to 7 .2 in a Japanese set per 100 ,000 years
• 3:43
  reported. Professor Robles, from your clinical
• 3:45
  experience in Singapore and Southeast Asia, does
• 3:48
  that broadly align with what you see in practice
• 3:50
  or do you feel dissections are more frequent
• 3:52
  or perhaps simply diagnosed and referred differently?
• 3:56
  Okay, so my impression is that Overall, we see
• 4:01
  far more dissections than aneurysms, be it thoracic
• 4:05
  or abdominal. And when I say dissections, I mean
• 4:09
  the aortic syndromes, a full -blown dissection,
• 4:12
  IMH, penetrating ulcers, and so on. We tend to
• 4:17
  see them at a much earlier age. The published
• 4:19
  average age is about 50 to 55 years. But the
• 4:23
  last two type 1 dissections I've been involved
• 4:26
  with in my hospital, were in their mid -30s,
• 4:29
  so they seem to be getting younger. We're seeing
• 4:32
  a ratio of type A to type B dissections of 2
• 4:36
  to 1, and they seem to be presenting a decade
• 4:39
  earlier than the Western published data. In terms
• 4:42
  of incidence, it's very hard to tease. It depends
• 4:45
  on the healthcare system. The Japanese are very
• 4:48
  good at collecting data, and I think one Japanese
• 4:51
  publication quotes 17 per 100 ,000 person -years.
• 4:56
  But in this city, they did image -guided autopsies.
• 5:00
  So all the pre -hospital deaths were recorded
• 5:03
  and they had a CT scan, non -contrast CT scan,
• 5:06
  which confirmed aortic dissection. So in clinical
• 5:10
  practice, this is just anecdotal, but you would
• 5:13
  often find when you are referred a case of dissection,
• 5:16
  the patient tells you the story of severe chest
• 5:19
  pain, rushing to the nearest big hospital. And
• 5:22
  because they are so good at doing a... what they
• 5:25
  call door -to -cath time, they end up having
• 5:27
  a coronary angiogram, which would be normal.
• 5:29
  And then only they discover that the patient's
• 5:32
  actually got a dissection. So that's the common
• 5:35
  scenario. So are you thinking that actually it
• 5:39
  might be much higher than what we're describing?
• 5:43
  Certainly it's higher than the incidence of symptomatic
• 5:47
  aneurysms. in Asia. When I train in the UK, we
• 5:52
  get many more aneurysms coming through. But it
• 5:56
  also may be that because we're sighted with a
• 5:58
  cardiothoracic unit, we are getting a lot more
• 6:01
  dissections than you would see in a standard
• 6:04
  vascular unit. So we may be skewed in that sense.
• 6:07
  We do see all aortic work coming through, be
• 6:09
  it thoracic or abdominal. Yeah, that's interesting.
• 6:13
  Another recurring observation in the literature
• 6:16
  is that in several Asian cohorts, particularly
• 6:19
  from China, patients with acute aortic dissections
• 6:22
  appear to present at a younger average age. So
• 6:24
  you mentioned this just now that in Western registries
• 6:27
  like in IRAD, sometimes by nearly a decade. As
• 6:30
  you said, your last two cases were even in their
• 6:32
  30s. So IRAD reports mean age. presentation in
• 6:36
  Western populations between 62 and 63, while
• 6:39
  data coming from the Chinese reports, albeit
• 6:41
  hospital -based data sets, are closer to 50,
• 6:44
  52 years of age. And you've answered this already
• 6:47
  a little bit, but is this a trend consistent
• 6:49
  with your clinical practice in Singapore? Can
• 6:51
  you tell us a bit about the numbers you're seeing?
• 6:53
  Yeah, so we don't have Singapore -specific data,
• 6:56
  but I did some research. We have hospital -level
• 6:59
  data from our neighboring country in Malaysia.
• 7:03
  They report the mean age for aortic acute type
• 7:08
  A dissection is 51 .6 years with a male predominance
• 7:12
  of 72 % and over 70 % of the patients are hypertensive
• 7:16
  or were hypertensive. I think this is in keeping
• 7:22
  with Asian data. It's about 50, you know, early
• 7:24
  50s is the average age of presentation for acute
• 7:27
  dissection. And you said that's what you're also
• 7:29
  experiencing in real life clinical setting. Is
• 7:33
  that right? Yeah, that's right. That's correct.
• 7:36
  So I'm curious as to why the Asian population
• 7:38
  might indeed present with aortic dissections
• 7:41
  at a younger age. Some hypotheses might be a
• 7:43
  high prevalence of untreated hypertension. You
• 7:45
  mentioned there that Malaysian study had 70 %
• 7:48
  arterial hypertension. But what about other things
• 7:50
  like lifestyle factors, possible genetic influences?
• 7:53
  What do you think is the most plausible cause
• 7:55
  for earlier presentation in the Asian cohort?
• 7:58
  Yeah, so we're not sure. We're still teasing
• 8:00
  it apart. Hypertension is the obvious one. We
• 8:04
  do look for that every time we find a young patient
• 8:07
  with a dissection. Primary care here, not universally
• 8:10
  good. Some people have access to good primary
• 8:12
  care and some don't. But sometimes we find a
• 8:17
  patient who's normal -tensive and cannot explain
• 8:20
  why they would present with an acute dissection.
• 8:22
  So we start looking at family history. any other
• 8:26
  relatives who would have died at an early age,
• 8:29
  you know. We are starting to do genetic testing.
• 8:32
  We now can send blood off for a panel of genetic
• 8:35
  conditions, about 90 conditions, not just Marfan's
• 8:39
  and Louis' and the usual ones, but even rare
• 8:43
  and esoteric genetic conditions. And we have
• 8:45
  genetic counseling as well. So that's starting.
• 8:49
  Another aspect we're looking at is sleep apnea.
• 8:53
  So I normally would ask the wife, you know, does
• 8:55
  the patient snore or sleep badly? And sometimes
• 9:00
  send them for a sleep study. And there's a lot
• 9:03
  of undiagnosed sleep apnea. So they get spikes
• 9:06
  of hypertension at night, not knowingly. Not
• 9:09
  much data. There is some soft data out there,
• 9:11
  but these are the things that I look at in practice.
• 9:14
  That's interesting. That'll be exciting to follow
• 9:16
  and see what comes out of there. Given Singapore's
• 9:20
  ethnically diverse population, perhaps it's ideally
• 9:23
  placed to dig into the reasons why certain groups
• 9:25
  might present earlier compared to others. In
• 9:27
  your personal experience, do you see meaningful
• 9:29
  differences between ethnic groups or are there
• 9:32
  other noticeable risk factors? Yeah, so I think
• 9:34
  with regard to the ethnic differences, it's really
• 9:37
  to do with compliance. Some are more compliant
• 9:40
  with taking... antihypertensive medication and
• 9:43
  some are not. So that may predispose them to
• 9:45
  cardiovascular disease in general, including
• 9:49
  diabetes. So that may be a compliance issue,
• 9:53
  not so much to do with the genetics. Okay, so
• 9:56
  in your opinion, the arterial hypertension is
• 9:58
  still in the forefront rather than ethnically
• 10:01
  genetic predisposition. Yeah. So moving into
• 10:05
  clinical practice, there's sometimes a perception
• 10:07
  in Europe that in parts of Asia, there may be
• 10:10
  a lower threshold for intervention in aortic
• 10:13
  dissection with earlier or more extensive surgical
• 10:16
  or endovascular treatment compared with more
• 10:18
  conservative medical management in selected cases.
• 10:21
  What is your take on that? Would you say that's
• 10:23
  an accurate statement? Yeah, that's hard to generalize.
• 10:27
  I mean, Asia is a big place. So obviously in
• 10:31
  Singapore and Malaysia, we would be more evidence
• 10:35
  -based, I suppose, in terms of our approach.
• 10:39
  And access to primary care is quite good generally.
• 10:43
  So if you wanted to treat a patient medically
• 10:46
  for type B dissection, that's quite realistic.
• 10:49
  They will be followed up every month. They can
• 10:52
  do a home blood pressure and so on. Telemedicine
• 10:55
  has also taken hold. country like China, where
• 11:01
  it's so big, sometimes that patient's presentation
• 11:05
  to hospital is the only time they're going to
• 11:07
  see a doctor. And when they go back to their
• 11:09
  village or even a small town, they may not get
• 11:13
  access to primary care. So that's the only time
• 11:16
  you have the opportunity to intervene. not unrealistic
• 11:22
  to to use a stand graph if you've got a uncom
• 11:25
  you know you can tell a slightly uncomplicated
• 11:28
  type b dissection with maybe a little burn or
• 11:31
  sorry a diameter of approaching 4 cm uh you know
• 11:36
  so that's done and that because there's such
• 11:38
  a big country the numbers look huge compared
• 11:41
  to everybody else right yeah so so it's a bit
• 11:44
  skewed in that sense Right. So you're thinking
• 11:47
  that maybe part of the reason that we might get
• 11:49
  that impression is, first of all, just because
• 11:50
  they have such higher numbers in general, just
• 11:52
  due to a very large population. And second of
• 11:56
  all, because they might strategically choose
• 11:58
  that because there might not be the same kind
• 12:00
  of access to primary care after that moment of
• 12:04
  presentation. Have I understood that correctly?
• 12:05
  Yeah. So what they call tier one cities, the
• 12:08
  big cities have the hospital facilities to do
• 12:11
  endovascular surgery. And patients may travel
• 12:15
  four to five hours from their secondary cities
• 12:17
  to get, you know, to see the doctor and then
• 12:19
  get treated. So they're draining a very large
• 12:23
  area. That accounts for the numbers. And then
• 12:26
  there's the question of follow -up. You know,
• 12:27
  if you were sitting in that primary hospital
• 12:29
  or tertiary hospital and you see the patient
• 12:32
  with the type B dissection and you know you can't
• 12:35
  follow the patient up, they can't come back in
• 12:36
  a month's time and do interval scans and so on,
• 12:38
  like we would normally do. This is your only
• 12:40
  opportunity to treat the patient. be able to
• 12:44
  admit the patient for a week or two at the most,
• 12:47
  and then they'll have to go back to their referring
• 12:50
  hospital, so to speak. So therein lies the problem
• 12:53
  with the logistics. I think they're getting better
• 12:57
  from the meetings we go to. The awareness, the
• 13:01
  follow -up is coming, the publications are coming.
• 13:04
  They're also quite good with the interventions.
• 13:07
  They don't seem to have a high complication rate.
• 13:09
  They have good conformable graphs. They don't
• 13:13
  oversize a lot. They just cover the primary 10.
• 13:16
  So they're quite sensible about their approach,
• 13:18
  I'd say. That's interesting. And we'll get into
• 13:20
  that a little bit. Would you say that they're
• 13:22
  also just more like particularly strong believers
• 13:25
  in immediate intervention, as well as the strategic
• 13:28
  idea of not being able to follow up the patients?
• 13:31
  Or is that a misjudgment? Yeah, can't comment.
• 13:34
  I mean, we see the publications and listen to
• 13:37
  the talks. Case by case, we've not reviewed the
• 13:40
  images. We just look at the overall numbers.
• 13:43
  So we're speaking about China right now, right?
• 13:47
  Just to be clear. Can you tell us a little about
• 13:49
  the landscape of the rest of Asia? What do you
• 13:52
  know about that? What can you tell us about that?
• 13:54
  So I think the big data comes from Japan. They're
• 13:57
  very organized. They have a national registry
• 14:00
  and national guidelines, which they have adapted
• 14:03
  from the US and some of the European guidelines.
• 14:07
  with their own epidemiological data and classification
• 14:11
  criteria and also levels of evidence for intervention
• 14:15
  and recommendation. So I think they're the most
• 14:17
  organized in their approach. Their published
• 14:19
  results are probably the ones that we look to
• 14:22
  in Asia as the benchmark. The other countries,
• 14:25
  we're not quite at that level yet. Hmm. Singapore
• 14:28
  is often seen as a bridge between Western and
• 14:30
  Asian worlds overall in the sphere of medical
• 14:33
  innovations for endovascular management of dissections.
• 14:36
  Do you have access to both the Western technology
• 14:39
  and the regionally developed devices? You mentioned
• 14:41
  a couple of them earlier. Can you tell us a little
• 14:43
  bit about the Asian manufactured stance or approaches
• 14:45
  that you think might deserve greater international
• 14:48
  attention? Yeah, so we have access to both. We
• 14:52
  have what's called the Health Science Authority,
• 14:54
  or HSA, which is pretty much like the FDA. Most
• 14:58
  devices have to go through quite a strong regulatory
• 15:00
  approval, but we are quite early adopters for
• 15:04
  new technology. So we've tried everything, obviously.
• 15:07
  If something works, then we tend to stick with
• 15:10
  it and then just evolve that way. For us, sometimes
• 15:13
  the... the Asian sense are a bit of a mystery
• 15:16
  because we don't really get to see them, right?
• 15:19
  So is there anything you can tell us a little
• 15:20
  bit about them? Okay, so this is a difficult
• 15:23
  topic because if you worked in the National University
• 15:26
  Hospital in Singapore, as you've visited us,
• 15:29
  we have access to most of the new devices. The
• 15:33
  paperwork's all done. The proctoring is done
• 15:36
  properly. The team has been trained, you know,
• 15:39
  and we do keep a registry and look at results.
• 15:43
  But if you were in a small hospital in another
• 15:46
  Asian country, let's say, you know, colleagues
• 15:50
  may be doing physician -modified endographs.
• 15:53
  And that's becoming very, very common now because
• 15:56
  they don't have access. So they may use a Korean
• 16:01
  stent and modify it or a off -the -shelf, shall
• 16:04
  we say, Western stent and modify it. uh so there's
• 16:08
  so much variation it's very hard to to put down
• 16:10
  but they're getting better at it i mean the results
• 16:12
  we are seeing is pretty good it's become a whole
• 16:15
  kind of a new industry a cottage industry you
• 16:17
  know position modified underground so you know
• 16:20
  even before we got access to a frozen elephant
• 16:22
  trunk we'd make our own and is there any ideas
• 16:26
  from the um asian stance that you would like
• 16:28
  to tell us about that you know maybe we're missing
• 16:30
  out on over here so there's some Chinese manufacturers,
• 16:34
  it's modified stands so that they're based for
• 16:38
  Asian anatomy, conformable to the lesser curve,
• 16:41
  double taper. The lumens are all smaller, so
• 16:44
  you don't need so much oversizing. Smaller delivery
• 16:46
  systems would help as well. But by and large,
• 16:48
  they're pretty similar designs. Good. I'm going
• 16:53
  to ask you a little bit about the guidelines
• 16:54
  now. You mentioned earlier that some of the Japanese
• 16:58
  have made adapted specific guidelines. What other
• 17:01
  guidelines might you draw our attention to that
• 17:03
  are used by and large in Asia? And what are you
• 17:06
  using in Singapore? Are there particularly helpful
• 17:08
  ones you'd like us to know about? Yeah, so the
• 17:11
  Japanese guideline is the most evidence -based
• 17:14
  and modified to their local data and recommendations.
• 17:19
  That's the standard that we aspire to. China,
• 17:22
  the Chinese guidelines are an expert consensus,
• 17:24
  which is adapted from Western guidelines. We
• 17:27
  are just digesting the ESVS guidelines. And I
• 17:30
  quite like the TEM system, because I think we
• 17:34
  need to move away from type A, type B, you know,
• 17:36
  because we are really doing an endovascular type
• 17:39
  of repair. So we need to think about landing
• 17:41
  zones and where the entry tear is and, you know,
• 17:45
  malperfusion and so on. So I like that TEM. Yeah,
• 17:49
  so we borrow from everybody is the short answer
• 17:52
  to your question. Are there any contradictions?
• 17:54
  Yeah, so I thought there would be a difference
• 17:55
  in the treatment recommendations for size. But
• 18:00
  I'm encouraged to see that the hinge point for
• 18:03
  treatment, both in the Japanese and the ESVS
• 18:06
  guidelines, is about the same. So I think that's
• 18:08
  quite reassuring. So before we move to the end
• 18:11
  of the podcast, I'd like to look ahead a little
• 18:13
  bit. So for the purposes of guiding future research,
• 18:17
  what do you see as the biggest gaps in our understanding
• 18:19
  of aortic dissections in Asia specifically? And
• 18:22
  what main hurdles are keeping us from filling
• 18:25
  those gaps? Yeah, so this was a question that
• 18:27
  we posed to ourselves maybe 15 years ago when
• 18:30
  a group of us started the Aortic Asia Symposium.
• 18:36
  And it's quite unique because It's centered between
• 18:41
  Bangkok, Hong Kong and Singapore. And in every
• 18:45
  country, there's a cardiac surgeon and vascular
• 18:48
  surgeon helming the meeting. So there's a mix
• 18:51
  between cardiothoracic and vascular surgery for
• 18:55
  aortic intervention. And, you know, as vascular
• 18:59
  surgeons, we actually learn a lot from our cardiac
• 19:01
  surgery colleagues and vice versa. So there's
• 19:04
  a lot of cross -fertilization. And we see their
• 19:07
  data, they look at our data, and then we sort
• 19:10
  of find ways of treating this disease together.
• 19:13
  And that's evolved over the last 13 years. So
• 19:16
  now, you know, we... It's changed our approach
• 19:20
  to treating patients with aortic disease. So
• 19:23
  we're trying to close the gaps, obviously. The
• 19:26
  meeting is now in its 13th edition, and we've
• 19:30
  reached a stage now where we're thinking about
• 19:31
  doing a Delphi -like consensus on... management
• 19:35
  of aortic disease in Asia, because we have enough
• 19:38
  experts from India, China, Thailand, Japan, Malaysia,
• 19:44
  Singapore, Korea, and with help from friends
• 19:47
  in Europe and the US who are already in the main
• 19:51
  European and US guidelines. So we can have a
• 19:54
  sensible and practical guideline for guiding
• 19:57
  Asian physicians in Asia. Is there any specific
• 20:00
  gap that you think people pick out as a topic
• 20:04
  to research? Yeah, so the low -lying fruit would
• 20:06
  be the TEM classification. If we can retrospectively
• 20:11
  look at our dissection scans and analyze that
• 20:15
  and see which patients should have been treated
• 20:17
  or would you have changed treatment, you know,
• 20:20
  based on that. And then obviously there's always
• 20:23
  that size issue. Are we, you know, putting in
• 20:26
  a stand that's manufactured in the West into
• 20:28
  an Asian patient and serving them appropriately?
• 20:30
  Or should we have different Asian? specific dissection
• 20:33
  stents. So a lot of it is morphology, anatomy
• 20:37
  and morphology. Yeah, so that's what comes to
• 20:40
  mind straight away. Then there are the rare ones.
• 20:44
  Genetics, I think, is a whole new thing. Why
• 20:46
  are we seeing younger patients? So to do genetic
• 20:49
  studies is quite expensive. And there are also
• 20:53
  implications for the patient and the insurance
• 20:55
  cover and so on. So we're quite mindful of that.
• 20:59
  You know, we're also looking at the possibility
• 21:01
  of false lumen illusion with smart polymers as
• 21:06
  a stage procedure after doing the acute dissection.
• 21:09
  So that may be the future. Okay, what about in
• 21:13
  the next decade? How do you think the management
• 21:16
  of aortic dissection in Asia will change? Again,
• 21:19
  coming back to the Aortic Asia meeting, when
• 21:21
  we started it 15 years ago, we were... talking
• 21:24
  about EVAs and fenestrated EVA. We thought that
• 21:28
  was the epitome of endovascular treatment. Now,
• 21:34
  two -thirds of the meeting is to do with the
• 21:36
  arch, arch branch, arch fen. So yeah, so that's
• 21:41
  changed in the last 10 years. So we are coming
• 21:44
  up to the arch and looking down into the aortic
• 21:46
  valve. Interesting. It'll be exciting to see
• 21:49
  what comes out. Thank you. Thank you so much
• 21:52
  for sharing your insights and all of your experiences.
• 21:55
  It's been a fascinating perspective. Thank you
• 21:58
  for making the time for us today. My pleasure.
• 22:01
  It was good talking to you again, Lauren. Also,
• 22:04
  thank you to our listeners for joining us in
• 22:05
  this episode of the ESVS podcast. We look forward
• 22:09
  to welcoming you again next time. Thank you.
• 22:11
  Bye. Goodbye for now.