Category Archives: vascular surgery

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!

https://drive.google.com/open?id=0B0vXFPRoqBg0NWJ3R2ljaVBSSmM

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 extensive aorto-iliac occlusive disease, and status post past aorto-iliac bypasses that failed and salvaged with stents and fem-fem. The fem-fem was infected and more stents were placed. She is now presenting with postprandial abdominal pain, weight loss and food fear, a classical presentation of chronic mesenteric ischemia, as well as right sided lower extremity rest pain. Her aorta had extensive calcification throughout, and there was no site adequate for an aorto-mesenteric bypass. Fortunately, extra-anatomical bypass was never done for her in the past. CT also revealed a patent hepatic artery despite severe stenosis of SMA, and angiogram 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.

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.

Take What’s Given to You

I attended the WNY vascular surgery symposium this weekend, and something Dr. Bower, chair of vascular surgery at Mayo Clinic said really resonated with me. He told the young surgeons and trainees in the audience to “take what’s given to you”.

Let me give this a little more context. Dr. Bower was talking about the slick open IVC reconstruction that they perform for primary and secondary thrombosis of IVC, and he was saying that one really has to look hard at feeding branches of these big vessels and control them as much as possible to prevent hemorrhage. I believe this notion can be applied to all surgeries, and to life. Not everyone is made the same way, just look at the variants of the aortic arch. Therefore, if life hands you a lemon, or take one away from you, you should be able to take advantage of the situation and change on the fly.

Image result for ivc reconstruction

Us medical students spend years learning about basic and clinical science. We learn about pathognomonic findings and evidence based guidelines. These information serve to steer us to the right clinical decision. To be able to adapt, however, we need to master these basic knowledge, go through rigorous training, and collect immense amount of experience. Eventually, when life hands you a lemon (you expose the IVC and find aberrant renal vein), you slice it and put it in a Corona (vessel loop, ligate, re-implant, etc).

Don’t blindly stick to any “rules”. Rules are there to guide you, but not define you. Be able to adapt to the situation, and do what’s best in each individual situation. Take what’s given to you, and milk the heck out of it.

Infra-popliteal bypass – longest case by far

Below is a short and sweet version of the longest surgical case thus far in my short and sweet medical career:

Patient is a 47 years old Caucasian male with IDDM, past stroke, past DVT, PVD, and HTN. He has a dry gangrenous ulcer in the plantar aspect of his right first metatarsal, and occlusion of anterior tibial artery. He is scheduled to undergo femoral to peroneal artery bypass with great saphenous vein.

Image result for popliteal to peroneal bypass

Common femoral artery cut down was performed first for pre-op angiogram; this was partially due to the uncertainty of where exactly the occlusion is and patient’s vascular anatomy. We saw completely occlusion of the anterior tibial artery and distal portion of the posterior tibial artery after the takeoff of peroneal artery. The popliteal artery and peroneal artery were patent. Next, the deep compartment of the mid calf was dissected from the medial leg to skeletonize the peroneal artery. We also skeletonized the popliteal artery because we decided convert the procedure to popliteal to peroneal bypass. Afterwards, we proceeded to looko for the GSV in the medial malleolus, but the vein was too small (lower threshold is 3mm in diameter, but ours was much less). Therefore, we retrieved the GSV from up to, following the sephaneous-femoral-junction. Finally, we heparinized, dilated and anastomosed the venous conduit. Due to the difficult, delicate dissection of the deep compartment of the leg, difficulty exposing the GSV, the changing of procedural planning intra-op, and not having the imaging study pre-op made the whole case around 10 hours. Luckily, the goal of re-perfusing the foot as accomplished, with biphasic pulse on doppler post-op.

The take away from this case is for me is the importance of being prepared before diving in. The fascinating part about vascular surgery for me is the options of choosing your strategies for the battle – like a tactician – may it be open, endovascular, medical, or expectant management. The choices branch out further with each category of treatment. However, in this case since we didn’t have a strong plan going in, we were not able to change our plan smoothly on the fly. The result? 10 hours of anesthesia for patient instead of 6. On a good note, there were lots of dissections and anatomy structures that I learned, rather serendipitously I would say though…

Finally, I learned the luxury of having a stool in a marathon case.