All posts by orjunkie

Comment on “Incidence of Myocardial Infarction After High-Risk Vascular Operations in Adults” by Yen-Yi Juo et al. JAMA Surg. 2017

Question raised by the paper – MI incidence in high risk vascular surgery didn’t decrease despite advanced cardiac care pre-op (2.7% 30 day MI in 2009; 3.1% in 2014).
My comment on this paper – This study only analyzed high risk procedure includes open AAA and infrainguinal bypass. Endovascular intervention was not included so SHOULD NOT BE MENTIONED ANYWHERE IN THE ARTICLE.
This study has poor generalizability. It is retrospective study on a very unspecific database. NSQIP database lacks specifics on location of cross-clamping in aortic cases and detailed perioperative medical management. Study population is predominantly white, and criteria for MI was not specified and only included up to 30 days.
With the advancement of endovascular intervention, more AAA and TAAA are treated with simple or complex EVAR (branched or fenestrated). The more emergency procedure in open AAA cohort reflects the makeup of open procedure for AAAs, as more and more elective cases of AAA are done endovascular. Open aortic procedure are also becoming increasingly complex, as the simple AAAs with adequate infrarenal aneurysm neck size, length, morphology are treated predominantly by EVAR. The leftover ones with aneurysm neck angulation and large diameter, juxtarenal/pararenal AAA, etc comprise the open AAA intervention. Thus, one can extrapolate that the open AAA procedures are becoming higher risk with expected poorer outcomes. It is no surprise that there is significantly higher actual incidence of post-op MI in open AAA repair [3.0%] vs [1.9%] in infrainguinal bypass, which is more of an elective procedure with subacute patient presentation. Therefore, pre-op cardiac workup and optimization are paramount. However, one cannot associate endovascular intervention with poorer outcome. EVAR, if anything, has made repair of AAA and TAAA into a low risk procedure, without the need for general anesthesia or cross clamp, and made even the rupture of AAA a controllable incident. It has made the cases of AAA/TAAA that require open approach more morbid procedure, but broad perspective that include all AAA/TAAA treated open and endovascularly would likely reflect an improvement in long term outcome of these patients.

Back to Basics

Happy 2018 everybody! Hope not many of your flights are getting delayed too much.

Also, you are not going to believe what I am going to blog about this time. I have just completed a rotation in neurology. If you follow this blog, you know that I am pretty gung-ho about vascular surgery. I guess I tend to find inspirations at unexpected places.

I wasn’t used to it at first. Coming in at 7am, pre-rounding on patients for 3+ hours, table rounding with attending for another 1-2 hours, and finally formally rounding on patients who are now taking afternoon naps. This schedule is different from surgery, to say the least. The amount of sitting probably gave me a badonkadonk.

However, nothing is all bad. Neurology rotation was 3-4 weeks of getting back to basic science and pathophysiology. I spent tremendous amount of time looking at new concepts and relearning old ones (pathogenesis of thrombus formation, atherosclerosis, embolism, etc).

Why is it easier to perform endarterectomy on arterial lesion caused by thrombosis versus Takayasu’s (the latter is associated with transmural inflammation so hard to find a plane)?  Why does intracranial vasospasm primarily give posterior headache (Posterior circulation has more sympathetic input)? How come temporal arteritis rarely affect intracranial vessels ( they have extremely thin walls with much less elastic fibers in the media and adventitia and absent vasa vasorum compared to their extracranial counter parts)? Those are few out of the many new basic science concepts I was able to learn and make clinically relevant during my time on neurology. Not only did I gain new knowledge, rotating in a medical subspecially like neurology taught me to always keep an eye out on the basic pathogenesis of every clinical disease. Indeed, medicine helps surgeon (or in my case, surgeon-in-training) quite a bit; much more than I thought.

I was once told by a mentor that to be a good surgeon, you need to know 2 things – pathophysiology and anatomy. It’s nice to brush up on the pathophys, an area that is easily forgotten if you spend a tad too long wandering in the other territories of medicine.

Anatomy = Technology?

Hey all, it’s been a long time. I am currently half way through the interview trail for 5+0 vascular surgery residency. It’s been busy, sometimes hectic, but definitely eye-opening and fulfilling experience. Visiting top-notch institutions, poking the brains of well-trained and well-researched surgeons, learning about the forefront clinical trials are all part of the interviewing experience that make the $100+ per night hotel stay and 20 hour per week at the airport worthwhile.
To keep this blog topic anonymous, let’s just say when I interviewed at a certain top 10 hospital, I had a pre-interview dinner with Dr. A. Dr. A is a sage who has been practicing vascular surgery all of his life, and who generously extended me the advice of making sure the “anatomy matches technology”.
When he spoke of this philosophical concept, his goal was to tell me to learn all of the options available in vascular surgery, choose what is most appropriate, and draw up plan B, C, D, etc since you have all of the options up your sleeve. This is a great advice, and frankly the most fascinating aspect of vascular surgery in my opinion. Having many ways of treating the same lesion is both interesting and cognitively challenging.
Let me give you an example of the philosophy of “anatomy = technology” in real life vascular surgery that made this concept really resonate with me. There is a new technique of treating carotid lesion that have developed in the past few years called TCAR (trans-carotid artery revascularization). To make a long description short, it utilizes flow reversal from common carotid artery to femoral vein to prevent distal embolization, while allowing a small incision above the clavicle for proximal control and to be the site of angioplasty/stenting, obviating the need to traverse through a hostile aortic arch in trans-femoral approach. Research (ROADSTER trials) has shown that the composite rate of stroke, death and MI rate 30 days after TCAR is smaller than traditional carotid endarterectomy. The vascular surgery world is pretty much split on whether TCAR should be more widely used, as it is currently only indicated for distal internal carotid lesion, high risk patient, redo/irradiated neck, etc as it is for transfemoral carotid stenting. You might ask yourself, what is not to like about TCAR, something that can save patients surgical wound, multiple days of hospital stay, and potentially fewer perioperative stroke?
I urge you to look at new device and technique development with open-mindedness but an objective attitude. This is a classic case of the necessity of making sure that “anatomy matches technology”. Sure, having TCAR allows patient with risky neck or high risk aortic arch to benefit from a small supraclavicular incision. Nevertheless, the traditional carotid endarterectomy is actually a very low risk procedure especially in the hand of a well-trained, experienced vascular surgeon. Some cite the stroke rate of less than 0.2%! For these surgeons, learning a new technique, and most importantly subjecting patient to a procedure that would cost them thousands of more dollars and one that still lacks long term data is much worse. For those of us who are more enthusiastic about TCAR (because it is after all another option in the repertoire), perhaps the right thing to do for now is to learn it well, but still discuss with the patient the possibility of referring to a surgeon with good endarterectomy outcome, if it is not us.
Being cool and cutting-edge is one thing, but individualizing to each patient and doing what’s best for the patient is the rule.

Outcome Research – Less Boring and More Power Than You Think

First and foremost, big shout out to the Eastern Vascular Society for hosting and organizing a thoroughly educational and enjoyable conference at Savannah, Georgia. I am writing this article during my second day here, staying at the gorgeous Westin resort. This conference is not as big as the SVS annual meeting, but it is more intimate and definitely just as informative. The few mosquito bites here and there are no biggie (I am blood type B).

The Westin Savannah Harbor Golf Resort & Spa (top), and the view of downtown from across the Savannah River (bottom).

Day one was all about dialysis; topics included access, maintenance, trouble shooting, and various decision making along the way. I would like to use the topic of dialysis access to show you the power of outcome research.

Many of you reading my blog are students, and I am sure some of you find outcome research in medicine boring, and frequently don’t seem like they apply to daily practice. I will show you that this is not the case, and it is in fact important to carry out more well designed studies and trials so we can create a “bank” of statistically powerful data so we can fall back on them when necessary.

When talking about whether hemodialysis is the best option for patients who are near the end of the road, Dr. Clifford Sales from Westfield NJ cited the data that in octagenarian with ESRD going on dialysis, the mean survival is around 1 year. This has tremendous implication on decision for creating dialysis access. Many of you know, the comparison between AV fistula vs. AV graft can be put simply that AVF is more durable and has less complications such as thrombosis and infection, but takes longer to cannulate and mature (4-6 weeks), whereas AVG can be cannulated much sooner (in 24 hours in some) but has less patency with prolonged use and more complications along the way. It is still advocated to create a native AVF in patients, but what do you think is the best choice of hemodialysis access for octagenarian with the mortality outcome data I presented to you earlier?

Answer is AVG becomes a much more attractive option, perhaps the preferred option. Why? It can be used quickly compared to AVF, so it brings the patient back to a relatively better quality of life when he/she is most likely at the end of the road. With survival of around one year, many complications associated with AVG would not surface, as it is not used long enough to induce thrombosis, infection, seroma, etc. This outcome data is amenable to change, as medicine progresses and octagenarian lives longer, even with ESRD (further highlighting the importance of constantly making progresses and updating on clinical research). In addition, patient with ischemic heart disease and ESRD have poor survival on hemodialysis, so delaying surgery for dialysis access and managing them conservatively are preferred.

You see the importance of clinical research on outcome of patient receiving treatment modalities such as different hemodialysis access, with different patient characteristics and co-morbidities. This has significant applicability on our decisions as surgeons, and definitely guides treatment. This is but a small example of many important clinical trial and followup studies that are going on currently. I urge all of you to learn your basics on the journey of becoming a great surgeon and doctor, but keep updated on the current research on your interested field.



Extent III TAAA Sandwich Technique – Apprenticeship from Dr. McKinsey

I just had a week of sub-I at Mount Sinai West, where Dr. James Mickinsey practices. For those of you who don’t know, he is internationally known for treating complex aortic cases, and the primary reason I was so excited to extend my stay one more day in this hospital that I have to travel 40 minutes each way. Below is a description for a sandwich technique for an extent III TAAA case I scrubbed.

Patient is a 84 YO AAM who has been followed by Dr. MicKinsey for an extent III TAAA that was >5.5 cm and had ulcerative plaques. The method of repair was going to be so called “Sandwich technique”, where chimney graft for visceral arteries will be sandwiched by two aortic stent grafts (schematics shown below). This technique was designed to bypass the expensive, time consuming step of personally designing fenestrated/branched TEVAR graft for each patient with TAAA that needs visceral artery coverage, and allows off-the-shelf selection of stent grafts.

Schematic drawing of the repair. Top picture shows deployment of first thoracic stent graft and cannulation of celiac and SMA from bilateral brachial cutdown. Middle drawing shows the finished product after sandwiching the balloon expandable stents in celiac and SMA by another aortic stent graft at the distal end of the first one. Bottom drawing shows the cross section design of the aortic and chimney stents, as well as gutters.

RIght CFA, with less iliac tortuosity was accessed and dilated up to 22F for deployment of the first thoracic stent graft, and left CFA accessed with 5F sheath for aortogram. Usually, axillary arteries would be accessed with cutdowns to cannulate the visceral arteries and deploy the chimney stents. Due to a history of hemi-facial and hemi-torsal burn with prior skin grafts covering the left chest and axillary region, cutting down on the axillary would lead to future skin breakdown, so we performed bilateral brachial artery cutdowns instead. One setback for the brachial cutdown is that since the patient’s arms would be abducted and extended, rotating the C-arm to get lateral fluoro views would be difficult. We solved this problem by abducting patient’s arm minimally, giving just enough space for adequate rotation of the C-arm. This might not be possible for obese patients.

Bilateral CFA were accessed first. Aortogram was taken to assess the TAAA, access vessels and visceral branches. Right CFA with less tortuous iliac artery was chosen to be the route of deployment of the first thoracic stent. Bilateral brachial cutdowns were done (an attending at each side with Dr. McKinsey monitoring outside, a common set up of lineup in a complex aortic case here as I’ve heard). The celiac axis and SMA were cannulated from above, balloon expandable chimney stents were inserted and deployed at the same time, with the proximal ends above the upper border of thoracic stent graft. The second aortic stent graft was deployed, sandwiching the chimneys, and the whole system was dilated with CODA balloon, but carefully avoiding the origins of celiac and SMA. Completion angio showed no endoleak. Whether or not to cover the renals then deploying a third aortic stent graft for a second sandwich were discussed, but due to the elderly status of the patient and the extent of coverage possibly leading to spinal cord ischemia, we decided to call it a day.

What a wonderful case that shows how far vascular surgery has come. From open surgery 20 years ago to endovascular cases nowadays, the field of vascular surgery has truly evolved with respective to time and technological innovation. Dr. Frank Veith (surgeon who performed the first EVAR in the U.S.) said in his presidential address during SVS annual meeting a while ago that vascular surgery needs to evolve like Darwinism. Dr. McKinsey’s practice is not only fascinating and unparalleled, but also definitely a representation of Dr. Veith’s vision.

Don’t Burn Bridges

I’m in the middle of my away sub-I at the Mount Sinai hospital in NYC. Frankly I have not been worked this hard since my crush in high school. Get up at 4am, rounds at 5:15, 3-4 cases through the day with barely enough time to shove down lunch, then rounds and conclusion of the days usually around 8-9pm. Even though I barely have time for leisure, I am learning so much and making great progress in becoming a great vascular surgeon. I think training here would be phenomenal.

Every Friday there is protected teaching conference. This past Friday, we went over a presentation on femoral-popliteal arterial diseases. When discussing the treatment options between open vs endo, something Dr. David Finlay said made an impression on me.

“Don’t burn bridges.”

That’s is the prerequisite of endovascular treatment. You give patient a better quality of life by intervening through endo but you shouldn’t burn future back up plans for bypass, or worse, turning a claudicant into critical limb ischemia.

Let’s say a gentleman with intermittent claudication after 3 blocks with calf pain comes to you for advice for failing medical management. You in your good grace decide to do diagnostic angiogram. You see a moderate CFA stenosis and a severe SFA stenosis in the right side. You plasty it but it is no better despite multiple attempts. What do you do?

This scenario touches the concept of preferential flow. When SFA becomes critically stenosed, the flow to lower leg switches to the profunda. Just like when the vena cava is thrombosed and the azygos system takes over. In this patient, the profunda is compensating for the flow to the lower leg. If you get too aggressive with endo and dissect the CFA, the whole system goes down and your backup plan becomes AKA instead of bypass.

A lot of factors affect our decision of how aggressively we intervene for claudicants, such as TASC II grade, medical stabilization, angiographic findings, success of medical management, etc. the most important factor that I believe is how much the claudication is affecting patient’s quality of life. We are not god, but what we can do and our ultimate goal as vascular surgeons is improve patient’s quality of life. Very frequently, the best treatment is let the claudicants be, especially if they tell you a story that doesn’t convince you their life is dramatically altered by their ischemia. I’ll Keep this in mind when I practice.

Listen to the patient, and don’t get aggressive with endo and end up burning a bridge that was elegantly built by patient’s own vascular anatomy.

Timely Aggression – Lesson from Poker

I’ve been playing poker ever since beginning of high school. Started with $10 buy-in tournaments with friends, then $20, $50… Eventually I was playing $1/$2 cash games, then $2/$5, $5/$5 PLO, and eventually capping at $5/$10 home games.

I was able to roll up my bank roll with disciplinary money management, reading away from tables, watching Youtube videos, googling advanced strategies, etc. One key lesson, among many others, is what I call timely aggression. It might take a long time to build up the image that you’re a manic gambler, but once you flop that made-hand, you play it aggressively like you would with your marginal hands and bluffs. People eventually pay you off with their marginal hands, while you hold the nuts. To sum this up in simpler terms – you appear aggressive while doing damage control with your bad hands, and you get similarly aggressive with your big hands.

Now, contrast this timely aggression with the management we choose in vascular surgery. This is appropriately illustrated in a case of endovascular case in a patient with previous open AAA repair with Dacron. The plan was to stent cover a new stenotic segment within the right common iliac portion of the graft. The surgeon met quite a bit of resistance when trying to advance the sheath before stent deployment. He forced it up, but angiogram after adequate positioning showed blowout disruption of the distal anastomotic site on the right, between the Dacron graft and the native subclavian vessel.

This image is pretty similar to the one I saw during M&M.

Instead of acquiring proximal control from contralateral side with balloon and opening up the groin (aka timely aggression), the surgeon decided to deploy a Viabahn stent over this rupture, basically creating a free floating tube with only radial force of Viabahn keeping itself in place. Meanwhile, patient continued to hemorrhage and became hemodynamically unstable, in the end requiring opening laparotomy to control the hemorrhage and repair of the anastomatic rupture.

Another option besides primary repair of the ruptured site is a aorto-uni-iliac stent graft, fem-fem bypass, and ligation of the proximal side of ruptured side.

When the situation calls for it, timely aggression with open vascular surgical procedure is needed. With endovascular approach being increasingly prevalent, the open procedures are a lost art due to decreased utility, training and some might call “laziness”. I firmly believe in the importance of betting my strong hand aggressively in poker, as well as being ready for open procedure and damage control when situation calls for it.

Podcast – Chronic Venous Insufficiency

Please feel free to listen to the unedited version of the podcast episode I created for Surgery 101, sponsored by University of Alberta. It is on chronic venous insufficiency, a topic I believe students do not learn enough about in medical school. My recording starts at 1 minute mark. Enjoy!

Axillo-hepatic-profunda bypass?

Say what?

That was my response when Dr. Linda Harris told me about her plan. She is the program director of vascular surgery here at University at Buffalo, and more importantly she is my mentor. However, I can’t help but second guess the words that were coming out of her mouth.

“Yap, I’ve done it before. It’s the only viable option we have left.”

Alright. Don’t have to tell me twice. I’m going to see this thing through.

The patient is a Caucasian female in her late 50s. She has extensive aorto-iliac occlusive disease, and status post past aorto-bifem bypasses that failed and salvaged with stents and fem-fem. The fem-fem then failed and more stents were placed. She is now presenting with postprandial abdominal pain, weight loss and food fear, a classic triad of chronic mesenteric ischemia, as well as right sided lower extremity rest pain. Her aorta had extensive calcification throughout, including the supraceliac region, and there was no inflow site adequate for an aorto-mesenteric bypass. Fortunately, extra-anatomical bypass was never done for her in the past. Duplex revealed retrograde flow at common hepatic artery and CT revealed a patent hepatic artery despite severe stenosis at other splanchnic vessels. CT with runoff showed a patent right profunda artery with distal collateralization.

So the outline of bypass was something like this:

In the end, the patient gained palpable right lower extremity pulses and audible doppler signal throughout the branches of her SMA.

Some takeaways and pointers from this procedures are listed below:

  • Tunneling via midaxillary line if axillo-fem bypass only; tunneled deep to the pectoralis major and into the abdominal cavity under the costal margin if axillo-mesenteric bypass. In this case, the tunneling was via right midaxillary line but one of the bifurcated limb of graft was swung over the costal margin into the peritoneal cavity.
  • Third part of axillary artery after emerging from pec minor was used for inflow. This part of axillary artery gives simpler exposure (need to split pec minor/major if more proximal part is used).
  • Ringed PTFE graft for simple procedure (no need for vein harvest) and it is protected from kinking compared to GSV.  However, if bowel were infarcted then GSV preferred due to less likelihood of graft infection.
  • Greater omentum was first sutured around the entry point of the graft into the abdomen and then invaginated over the main body of the graft using interrupted Vicryl suture to exclude it from peritoneal cavity.
  • Interposing vein collar/cuff was not used, but it might have been a good idea…
  • The smaller size of graft is preferred (8mm). A larger diameter will result in slower velocity, increasing the buildup of pseudointima.
  • Endarterectomy of visceral arterial ostium not possible due to no clamping site at supraceliac aorta due to calcification. However, this might be an option if clamp site as present (or do a thoraco-hepatic-profunda bypass)
  • Endovascular intervention was out in this case due to prior aorto-bifem (thrombosed proximal CFA) and supraceliac calcification (rendering brachial approach difficult).
  • Axillary inflow might just serve as a bridging procedure to allow temporary clinical stabilization and definitive reconstruction at a later date. However, in this patient it will likely serve as definitive repair.
  • Renal arteries were patent in this patient, so even though aortic plaque usually originates at the infrarenal aorta, this patient just had ostial lesions at the visceral branches and atherosclerosis of supra celiac region, which represent a rarer progression of aortic atherosclerosis.

If one knows what she is doing, one can achieve great things in what seems to first timers as really funky ways.

SVS Annual Meeting – A Carnival of Expert Surgeons and Professors

This is my 5th day in the stunning San Diego for the 2017 annual meeting of Society of Vascular Surgery. I would just like to say that a less than a week of exposure among these brightest minds of vascular surgery beats months of clinical rotation. You name it: cutting edge research symposium and lectures, technique simulation and practice, exhibition of new technologies for the OR, networking with renouned surgeons and professors (Dr. Frank Veith!), and even mock interviews with program directors. I would highly recommend this event to anyone who is interested in any surgical specialties, or just want to explore the still not-so-well-known field of vascular surgery. They are generous with their scholarships, so apply for them and they just might pay for your trip next time.