Amazon Set Your Kindles Free

Posted on by docpark

My Lenovo Yogabook C930 recently got a firmware update where the main screen image gets cloned to the e-ink display. By putting the device into tent mode, the LCD screen turns off and you now have a PC on an e-ink screen. Linked to a Bluetooth keyboard, it is a low power focused writing station, albeit with lag. Like other e-Ink screens, there is lag -kind of like a typewriter, but you can see it in full sunlight and theoretically there should be a benefit to battery life although I am holding my horses given the Intel chip burning in this device. I have been advocating for this feature for my e-ink Kindle readers. Imagine if you can write a book on a Kindle! It would be a simple OS update. Come on Amazon! Turn on a simple text editor and sync to the Amazon cloud and call it “Author.”

Kudos to Lenovo for the firmware update. I feel like I am part of a giant beta as the Yogabook C930 is gloriously half-baked. The fingerprint reader is still dreck. Freewrite should take note and hurry up with Traveler!

Of Clot, Tofu, and Cheese

Posted on by docpark

The process of clotting is something vascular surgeons take for granted, but patients may have a hard time understanding what a clot is because in most people’s experience, it is rare for someone to see enough blood to form clot. How many patients or even health care providers have seen a tube or a basin of blood clot? So how do we describe clot to patients? I think the solution lies in food.

Most people who know me will say that I propose food as the answer for most things but hear me out. In describing clot, food is particularly salient. Clot is protein made insoluble, and there are many foods that have similar properties. Tofu, jello, and cheese and their making can give context where the word “clot” cannot.

All are made by taking a solution of protein and allowing them to form clumps that cause them to fall out of solution. It may require an acid, as in the case of tofu and cheese, but mere time and cooling may be sufficient as in the case of jello. And like these, clot may take on a soft crumbly quality when it is fresh clot, to a tenacious formed clump when given enough time. The difference is like silken or soft tofu and firm tofu. Or fresh ricotta cheese before it has time to set in its mold and the firmer cheese you get after weeks of curing.
With enough time, you get a hard substance that you can slice with a knife, like a dry cheddar or Parmesan. That is how I think of clot. It can be soft and formless like early jello before it is ready to eat. Or it can be hard and formed like mature dry cheese. The softer it is, the easier it is to dissolve or suck out via gadget or catheter, but there is a time factor to this softness -thing of your jello setting and hardening in your fridge. The harder the thrombus is, the less likely it is you can remove it with catheters and more likely you will have success with an operation as in the first picture. The harder stuff in fact crumbles well like a parmesan cheese and is harder to remove.

Burrata, handmade in Calabria is similar to the kind of semi-mature clot that deforms well but is tenacious and difficult to break up and remove except in one piece.

There are several things to draw from this with regard to devices designed to retrieve clot. Clot can occlude catheters as much as they can occlude arteries. Clot retrieval depends on net output of fresh clot that deforms well and flows well but fails in the hardened brittle clot that is well organized and adherent. Retrieving these crusty dried clot matter may be impossible for a device that depends on clot deformability or a maximum particle size, and these clots are the ones that are more partial to crumbling and embolizing. All devices must accept the fact that the unclogging is done in a flowing circulatory system where items swept downstream have the consequence of killing tissues whose arteries are blocked by emboli. There is always embolism with minimally invasive approaches. These devices make sense for hard to access circuits like the brain, but make far less sense in circuits like the extremities where surgical control is relatively low risk and results in reversal of blood flow -like in TCAR. Each of these devices can cost several thousand dollars. The fact is, operations can be faster and safer because embolism can be controlled and a wider range of clots, and larger amounts of it, can be removed at a lower cost. The first picture shows the results of a popliteal cut down and tibial thrombectomy where inflow was first restored in the below knee popliteal artery, and clot retrieved from each of the three tibial vessels (misleadingly, the tibial thrombus is all lined up), and a simultaneous 4 compartment fasciotomy performed, all under 90 minutes with no use of contrast. Unfortunately, open thrombectomy is a bit of a lost art in that many of the maneuvers and steps required to revascularize a limb successfully with no preoperative imaging requires experience. A younger patient with an arrthymia related embolism and normal soft arteries is approached far differently from an older person with atherosclerosis and diabetes, where open thrombectomy is better suited for the first, and catheter based approaches better for the latter.

Diagnostic and Therapeutic

The open surgical exploration of the extremity arteries is fast becoming a lost art along with the physical examination. In the setting of acute limb ischemia, the first decision in my mind is: was this an embolism? The presence of arrrhythmias, cardiac shunts, and aneurysms may suggest this, the next question is did this patient have a prodrome of limb ischemia related symptoms and history of atherosclerosis. The fact is, you have about 4-6 hours to return blood flow before irreversible neuromuscular damage sets in, maybe less if important collaterals are lost. Choice of procedure then devolves to choices about the most expedient methods for returning blood flow to the extremity, and between endovascular procedures and open surgery, it is rarely possible to manage significant clot burden with endovascular methods without adding the burden of procedural time. These considerations are balanced by patient risk. If the patient cannot tolerate general anesthesia, it is still possible to operate under local anesthesia. Otherwise, one is faced with choices like stenting across clot or common femoral artery. The algorithm is simple -ensure inflow, thrombectomize outflow, check for backbleeding, restore flow, check flow, repeat as necessary downstream. Fasciotomy as needed and close the skin if you can.

Endovascular options deal with the basic physics of trying to pull clot of varying consistency through a small lumen over a long length while not pushing emboli. The needs are simple -a low profile, cheap, over the wire solution for evacuating clot without embolizing nor injuring the patient on a 100cm and 150cm length catheter. Cost wise, open surgery always beats any endovascular option if wound complications of open surgical exposure are avoided. Both methods can’t cover themselves if open fasciotomy wounds keep the patient in the hospital for weeks. The fact is, we already have this magic system in the catheters that we already have on the wall, albeit, they don’t work particularly well if you are dealing with Parmesan, but none of the systems do. I recently declotted a graft fistula with just 6F sheaths, a regular #3 Fogarty ballon, 6mg of tissue plasminogen activator, and was able to salvage the blood and return to the patient.

Conclusion

Vascular surgeons should have as many words for clot as Eskimos purportedly do for snow. There is no one solution to a problem, but all the tools must be available to the vascular surgeon. Ironically, only the simplest are needed most of the time.

Distraction free writing used to be the norm with technology

Posted on by docpark

IMG_0645

Distraction Free Writing: Portable, Disconnected, AA Battery Powered

Distraction free writing has been a buzzword. It used to be the norm with computers by their limitations and design to focus you on writing. Today, technology is increasingly put in front of you to entertain and distract. The problem for students and writers is that your computer and phone are gateways to music, video, and communication in ways that were only dreams twenty years ago. The key elements of distraction free writing are a decent keyboard, extended battery life, simple interfaces, lack of connectivity, and   absence of party line operators. Each of these elements formed the core of our computers back in the 1980’s, when computers were rarely networked, they were all monochrome, and your words were all that you saw. This desire is driving the market for distraction free writing software and hardware, but you can find ways to create your own portable distraction free writing tools without dropping a fortune. And distraction-free writing is also intrusion-free -something to consider in today’s shifting privacy boundaries. At the end, the best distraction free options may be in reconsidering decades old devices that may be picked up cheaply used or at greatly reduced prices for new. Most current devices are made to last about a thousand recharges, and struggle with purposeful obsolescence. You may find that there are many fine older options that will suit your writing needs while greatly increasing your productivity while avoiding costs.

Consider the keyboards we had back in 1985. They were all mechanical spring keyboards which made a nice click sound. Writing was a tactile pleasure. This was in contrast to the membrane based keys seen on games and toys, and mistakes like the PCjr. You see them today as controls for microwave ovens. The moving keys send a message of accomplishment to your brain. Despite this, flat keyboards with no physical component  are still being thrown up to see if they would stick. The smartphone keyboard on the first iPhone killed the physical ones on Blackberry and the Treo’s after all. Manufacturers are still experimenting with flat keyboards such as on the latest Yoga Book’s e-ink keyboard, and the upcoming Microsoft Surface Duo devices.

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flat screen based keys like on the latest Yoga Book takes some getting used to

These software and touch display based keyboards rely on spelling correction and ultimately constant connectivity to minimize error. The push for ultra-portability means dispensing with the original mechanical keyboard which was descended from electric typewriters like the IBM Selectric. This resulted in the terribly mushy, mass produced keyboards introduced in the 1990’s, getting ever worse. The high point of this design viewpoint was introduced in the 2015 MacBook and recently retired in the 2019 Macbook Pro when Apple realized everyone hated typing on superflat keys meant to accommodate flatness over functionality. There is a welcome movement back to reasonable keyboards. I would even claim that the persistent life and value of the Thinkpad line is the focus on the keyboard that remains preserved after IBM sold it to Lenovo. The new-old keyboard on the 2019 MacBook Pro 16’s are a concession to the realization that typing is a core function of these machines.

There is a push back as writers, office workers, and gamers have created a market for mechanical keyboards. These are usually Bluetooth connected devices, and typically paired to tablets for writing. Unfortunately, separate keyboards connected to tablets are not as portable as a laptop.

QWERKYwriter is a retro mechanical keyboard for tablets but try taking that onto an airplane

I would argue that laptops are not as portable as they could be. The Freewrite (link) was designed with writers in mind as an update to electric typewriters with cloudbased file management and an e-ink display with days of battery life on a single charge. I almost bought one but the small display and the relatively bulky size kept me from springing. I have ordered a Freewrite Traveler (link) which is their mini-laptop version, but since I ordered one last spring, it has remained vaporware with its delivery date pushed back from summer 2019 to spring 2020.

Battery life is a sore point for me. Laptops are now expected to be wonderful if they exceed 8 hours of battery life, but I remember that the original portable computers like the Radio Shack 100 series could go days on AA batteries. Writing appliances were introduced in the 80’s including electric typewriters with single line LCD displays and single file memory which would allow you to compose and edit. I had such a device from Japan in high school that had a four line LCD display, built in thermoelectric (fax paper) printer, and battery life that went several days on 4 AA batteries.

By using computers and smartphones, which function as portable televisions and multi-function, shopping kiosks which use Watts of power, the trade off is battery life and constantly worrying about plugging in for a recharge. We forgot the days of battery life and are happy with 8 hours. The battery power bar is terribly distracting for me and I tend to stop working to find an outlet to recharge when it inevitably drops and when my productivity is nearly always highest. If I’m traveling, this means carrying the power brick, another injury to this one who remembers AA battery powered writing tools.

In 2017, the Samsung Galaxy Note 7 was famously recalled after spontaneously combusting and were banned from airplanes. All Lithium batteries must now be hand carried. Just recently, I was told while checking in that Apple Macbooks could not be turned on during flight because of heating issues. This is a consequence of the greatly increased energy densities of Lithium cells and their chemical volatility. AA batteries and their nickel metal hydride (NiMH) rechargeable variants suffer from no such problem.

Even with great battery life, you have to remember most of that power, and therefore bulk and weight of the Lithium batteries is devoted to painting vivid colors on the screen, communicating via radio signal to the world, and keeping dozens of apps updated on your activities, and not to writing.

The Lithium battery which can power a car because of its energy density is overkill if all you want is to write. The modern computer operating systems, Windows, MacOS, iOS, and Android, are all over-powered for the simple act of preserving words. Consider the lowly text file to a modern Word file. The text file for a novel might take kilobytes of memory, but the same Office Word file is measured in megabytes -thousands of times bigger. Try emailing a fully formatted Word file through your corporate firewalls if it exceeds your company’s limits on attachment file sizes. The size and complexity of information that is exchanged burns power. Compare that to the notes you might write onto paper. The few microcalories used to power your neurons and move pencil on paper, the motor and optics circuitry processing the information at a speed suitable for your ape brain.

My friend and early mentor, Professor David Tilson, refused to relinquish his DOS based word processor even well into the Windows era. And I understood. The monochrome and monotype letters forced you to look at the words and not the style of the words. While I admire Steve Jobs, and his introduction of fonts to our everyday lives, the ability to shape the look of your writing intrudes on its composition. Monochrome does not mean monotonous, and modern distraction-free software efforts like IA Writer embrace simplicity. The emergence of dark mode is another effort at rolling back the clock. When you enable it for your iPhone, it reaffirms the utility and critical need for focus and simplicity. Do you need millions of colors or just letters on a simple background? While you can change the color setting of your laptop screen or your writing software, the ultimate in monochrome experience is an e-ink display.

The e-ink display is what you see on Amazon Kindles. Originally meant for low power usage, high contrast functions like in store signs, e-Ink is currently used for e-Readers, although there is a niche market for e-ink based displays and tablets which do offer the low power hi contrast display perfect for a focused writing work station – you can find them on Amazon and eBay. Unfortunately, because these e-Ink tablets are run typically on Android, there is no escaping the internet on these, and because they do so, their battery lives are not that much different from standard tablets. What the we need is for Amazon to gift the writers of the world with Bluetooth or wired keyboard functionality to their Kindles and offer a text writer that can be synced to their cloud..

What the we need is for Amazon to gift the writers of the world with bluetooth or wired keyboard functionality to their Kindles and offer a text writer that can be synced to their cloud.

The constant need for connectivity drives software and hardware inefficiency. Writing requires intimacy and privacy. Just as you cannot write while engaged in a shouting match with someone, you cannot write with notifications of arriving messages, pictures, and videos. I cannot write while watching a movie or listening to certain music, but all of these distractions are baked into the function of modern computers and smartphones. This uses up battery life. The devices are in a race to maximize the battery and screen size at the cost of purpose and meaning aside from commerce.

Party line operators were a feature of the early telephone systems. Your locality was serviced by an operator that routed your calls and inevitably your conversations were open to intrusion both intentional and unintentional. When all your work is kept on a cloud server, it really is no different. And it isn’t that hackers that may take all your work. My generation grew up with the Cold War, and its dark tales of thought crimes and writers imprisoned for samizdat -ideas forbidden by a state entity. In a time when your social media is a subject for governmental and not just consumer interest, returning to off line options is something to consider seriously. The meaning of party line operators is in this context wholly changed.

The one feature of cloud based options is the convenience of accessing it across all of your devices. But are you really going to be writing on your iPhone, then on your desktop, then on your laptop, then from an airport kiosk? Your file can be lost during the sync process or changed to a competing version from another computer you were working on. And goodbye work if you get hacked or if your cloud service shuts you down or out. While you write, you have to keep a local version and back up to a nonvolatile storage option.

Not connecting to the internet saves you battery life. It also frees you from taking deep YouTube dives into funny cat videos or answering emails or Facebook posts. The stillness you need to just write is difficult to achieve with a modern laptop, tablet or smartphone. It can be attained with these older devices which people in the know still value decades after they left their boxes. I suggest these options if you are thinking of trying a focused writing appliance (a typewriter!).

Option 1: King Jim Pomera DM100  (link) is best described as a writing appliance designed in Japan adapted for the English speaking market. It is a sleek thin portable that allows one to type words unencumbered by internet. The files on it can be transferred to another computer by Bluetooth, and to smart phones by QR code which is cool. It runs for days on AA batteries, and has a backlit monochrome LCD screen. It is priced on th high end at 392.61, but receives the best rating on Amazon which to me is a 4.5. I never come across 5 star reviews that aren’t fake. One reviewers comment that the keyboard is cramped and takes getting used to. It can be used as a Bluetooth keyboard and stand for iOS devices.

Option 2: Neo 2 Alphasmart Word Processor with Full Size Keyboard,, Calculator

The Alphasmart Neo2 (link) was the last of a line of writing appliances put out by a pair of former Apple engineers who wanted to provide affordable word processing options on a full mechanical keyboard. The Neo2 is the most available and apparently the most usable, allowing one to type out hundreds of pages and transfer to a computer via USB connection. The screen is an LCD screen like on a calculator. The killer feature on this device is nearly forever battery life on AA cells. It has a rabid following of professional writers who appreciate the pared down experience for productive writing. It achieves that perfect 4.5 star rating. This is for a device discontinued in 2007 and sells for about 40-50USD in used condition. Reviewers rave about turning it on and instantly being able to type without bootup, and avoiding distraction by email, notifications, social media etc.

Option 3: Psion Series 5MX

The Psion Series 5MX represented the apex of portable computer design in the late 1990s. It was a computer made from the ground up from circuits, hardware, operating system, and apps by British engineers and it was a thing of beauty. Made in the late 1990’s, this device’s killer features, long battery life via AA cells, ultraportabiity, and lack of easy internet access puts it in a separate class. Not everyone like the keyboard, but I have long been able to type on it without difficulty with average to large sized hands. I had one during residency in the 1990’s and it followed me into fellowship. Before EHR, I composed full consultation notes and H&Ps on it and filed them on my password protected CF drive for later retrieval and update for frequent flyer patients. I picked up a pair of these for about 90USD from the Netherlands, but the going priced varies from about 70 to 200USD for a used one in good condition. New ones pop up but they go for nearly their original price -they are that good. I suspect I got a deal because they were Ericsson MC218, a Swedish licensed clone.

It has a compact flash drive, and with the save as text file function in the built-in word processor which works fast and reliably, it is possible to back up to a nonvolatile memory (the CF drive) and transfer to a regular computer. The one caveat is that the maximum size of CF drive it will see seems to be 128mB -that is megabytes which is hard to find. In certain older industrial machinery, instructions are uploaded via CF cards of these size, and so these cards are available on Amazon. Or look in a drawer for an old unused CF card.

I wrote this post on the Psion, and never once looked at emails, social media, or Youtube.

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I wrote this post on the Psion, and never once looked at emails, social media, or Youtube.

The shunt as temporary bypass -a modest proposal

Posted on by docpark

The rise of cardiopulmonary bypass life support has also given a rise to the need to keep large, obstructive cannulas in femoral arteries. ECMO cannulas are often kept in for days, and it is not uncommon to discover limb ischemia and infarction relatively late. This can be avoided by placing a distal perfusion cannula to shunt blood to the leg early in the ECMO process. The ECMO cannulas have a convenient side port to send a little flow to a 6F sheath placed in the femoral or popliteal artery. This is an established technique (reference 1, sketch below), and it works despite the modest flows achieved because it does not take much to keep the leg alive. These patients are not walking, nor are they need to heal leg wounds, so just enough blood flow means something just a little more than what they get when the common femoral artery is completely occluded by the life support cannulas. What is fascinating to me is that these shunts can pptentially help to save limbs when used as temporary extracorporeal bypasses when definitive vascular surgical care is not immediately available.

brachial to femoral shunt sketch

 

When I was a medical student, I took on a research project after my first year where I had a Langendorff preparation of a rat heart (below).

langendorff prep in MRI
an isolated, perfused, beating rat heart placed in a superconducting magnet for NMR spectra acquisition 

My project was to take a rat heart and keep it alive, beating, and even working, through a perfusion apparatus and place this inside a superconductive magnet to obtain Phosphorus nuclear magnetic resonance spectra -intracellular metabolism data including concentration of ATP, intracellular pH, and ATP/ADP ratio. While the project was successful -I am quite proud to have been the only person at Columbia to have successfully acquired NMR-S data with living beating heart, I moved on to other interests and took away this concept: with oxygenated, glucose enriched, isoosmolar fluid perfused at arterial pressure, any organ can be kept alive, possibly indefinitely, including a brain which only recently others have found possible (reference 2) in reputable scientific circles, but the the Nature publishing Yalies were scooped by the Simpsons decades ago (below), and maybe Mary Shelley centuries before,

simpsons head

This is the simple idea. Revascularization is keeping the target vascular bed alive by delivering oxygenated blood. With a shunt, it could be little, it could be a lot, but it certainly is better than zero, and even a little can buy you time.

The breakthrough that I had was several years ago, a patient arrived from another hospital with an Impella pump which did not have a side port like an ECMO cannula. It is a large catheter that augments cardiac output and in the patient that I was asked to see this patient as their leg was cold and pulseless. Their cardiac output was very poor, and they were sustaining an augmented systolic pressure in the 90’s. There was no way to get this patient to the operating room for a revascularization of any sort. It did strike me that the patient had the misfortune of having catastrophic heart failure in the absence of significant athersclerosis and had normal brachial arteries. After discussing the ramifications with the ICU and family, I placed a brachial artery 5F cannula, and connected it to a 5F sheath I placed in the superficial femoral artery below the occlusive common femoral sheath (figure below). A doppler on the tubing connecting the two cannulas confirmed flow and the patient’s left hand maintained a pulsatile oximetry waveform. The leg pinked up and eventually there was a signal in the foot. This managed to perfuse the leg which did better than the patient who succumbed to multiorgan failure from heart failure. The leg did great.

Which leads me to these thoughts. Most hospitals are good at diagnosing large vessel occlusion via CTA. Most hospitals have doctors who can place arterial lines with ultrasound guidance. In the instance of aortoiliac occlusion or femoral occlusion from thromboemboliem, time is a critical limiting factor to limb salvage. Many hospitals do not have vascular surgeons. Many hospitals transfer these patients with a heparin drip but in the ischemic condition. Transfer arrangements may take hours. Why not ameliorate this situation by having an appropriate physician -an anesthesiologist, an intensivist, an EM physician, place an ultrasound guided radial or brachial arterial line, connect to arterial line tubing to a dorsalis pedis arterial line. Tape it all down on the patient after confirming flow (crude sketch below). This would be better than the three extra hours of ischemia the patient gets hit with on transfer. No one would transport a donor kidney without adequate perfusion and protection, but dying legs get transferred all the time with established warm ischemia. If done well, it might turn an emergency procedure into an urgent, semi-elective one. Have the vascular surgeon video conference in to confirm the absence of blood flow and appropriateness of temporary shunting.

radial to dp shunt
radial artery to dorsalis pedis artery shunt

If we are to live in  a world with less vascular surgeons, then the radius of survival has to be extended with use of technology and simple ideas such as this. Comments are welcome.

Reference
1. Foltan M, Philipp A, Göbölös L, Holzamer A,
Schneckenpointner R, Lehle K, Kornilov I, Schmid C, Lunz D. Quantitative assessment of peripheral limb perfusion using a modified distal arterial cannula in venoarterial ECMO settings. Perfusion. 2019 Mar 13:267659118816934. doi: 10.1177/0267659118816934.

2. Vrselja, Z., Daniele, S. G., Silbereis, J., Talpo, F., Morozov, Y. M., Sousa, A. M. Mario, S., Mihovil, P., Navjot, K., Zhuan, Z. W., Liu, Z., Alkawadri, R., Sinusas, A. J., Latham, S.R., Waxman, S. G., & Sestan, N. (2019). Restoration of brain circulation and cellular functions hours post-mortem. Nature, 568(7752), 336–343.

Never say never

Posted on by docpark

fem-at-bypass.jpgIf you work long enough, you will not only see everything, but you may end up doing something that you say you would never do. You will be confronted with a scenario that would test not just your skills but also your boundaries. The adage, never say never is a warning that all of us may face a choice -to remain rigidly consistent with some earlier proclamation or to excuse a little hypocrisy for the sake of the patient.

At one point in recent years, I saw a patient who had an axillary artery to anterior tibial artery bypass with PTFE (figure above). That was a kind of marvel to me, but my initial response was a bit of a sneer.

“Who does this?” I thought.

Giving it some thought, the rationale could have been to spare the patient from a hip disarticulation as the patient had had failed revascularizations and was occluded from the infrarenal aorta to the anterior tibial artery on that side. If you see such a thing, it sparks wonder as it feels both wrong and splendid at the same time because some surgeon had the audacity to pull it off. By the time I saw it, the patient had avulsed the proximal anastomosis, infarcted their leg to their thigh, and was headed for a hip disarticulation, four years after the creation of the bypass. Four years of patency!

It was no wonder I remembered this case when this middle aged man presented to our clinic with a gangrenous right third toe. He had diabetes, hypertension, CAD with prior PTCA, prior acute mesenteric ischemia with bowel resection with an SMA stent, CHF with moderately reduced EF, CKD, and aortoiliac occlusive disease treated in past with aorto-bi-iliac bypass, left to right fem-fem bypass complicated by graft infection requiring resection of the fem-fem bypass, with subsequent development of rest pain on left leg and gangrene on right leg. He had been told at his home institution that he required eventual bilateral hip disarticulations. At the time of consultation, he was minimally ambulatory, limited by severe pain. He had been this way for over a year.

On examination, he had heavy scarring in both groins from prior open incisions healed by secondary intention, a midline laparotomy incision. He had weak bilateral axillary and brachial artery pulses. He had no pulses in either leg. The right foot had gangrene of the distal phalanx of the third toe. The both feet were anemic and painful -the left foot had more dependent rubor. Pulse volume recordings were flat in both legs. TCPO2 was in the 20-40mmHg range at the thighs bilaterally suggesting reduced potential for healing an above knee amputation. Vein mapping showed no suitable saphenous vein in either leg. CTA (figure below) showed both external iliac arteries to be occluded or absent and the common femoral arteries to be occluded or missing bilaterally.

AngioRunOff 1.0 B20f

The left femoral bifurcation was preserved and the left SFA was patent into small underfilled tibial vessels. On the right, there was an isolated segment of profunda femoral artery that reconstituted from pelvic collaterals. The right below knee popliteal artery reconstituted and had underfilled but patent three vessel runoff (figure below).

AngioRunOff 1.0 B20f (4)
posterior view of right popliteal reconstitution

The patient was admitted for workup and treatment. Heparin drip was started. In the setting of rest pain, I find that heparin drip improves circulation and symptoms even though it shouldn’t. I don’t have a great explanation for this, but it does, and I would welcome comments. To better assess how much operation the patient could tolerate, a cardiac risk assessment was performed. He was deemed a moderate to severely elevated risk due to his EF of 35% but had a normal nuclear stress test.

The options I presented to the patient were
1. Hip disarticulations
2. Bilateral above knee amputations with a wait and see approach to hip disrticulation
3. Sympathectomy
4. Axillo-profunda or popliteal bypass on right and Axillo femoral bypass on left
5. Ilio-right popliteal and left femoral bypass.
6. Thoracic or supraceliac aorta to right profunda and left femoral bypass

Hip disarticulation is the bogeyman of leg amputations done for peripheral vascular disease. When done for trauma or cancer in young people, the ability to rehab and walk again is excellent. When done for tissue loss in elderly, non-ambulatory patients, the reported mortality of the operation rises to above 50%. It is usually posed as a lead in to comfort measures. The above knee amputations were not likely to heal despite the neither here nor there findings of the TCPO2 which is only good when the results or normal or dismally low. Sympathectomy is an option for those without options, but this patient still had options, I felt.

Any revascularization relies on the choice of inflow, outlow, and conduit. In endovascular revascularizations, the conduit is the previously occluded vessels, but in this instance, because of the infected grafts, there was neither continuity, nor a good option even if there was as the common femoral artery is a terrible recipient of endovascular therapy. The options then devolve to choosing an inflow. The axillary arteries are technically easiest to access and manage and form the basis of treatment of high risk patients requiring limb salvage who have no endovascular options. The axillofemoral bypass is given a bad reputation of having a poor patency, but the key is the quality of the vessels and the number of potential tension, compression, and kink points. I think the reason why the axillary to anterior tibial bypass lasted for four years in the first patient had to do with his immobility, and the pristine nature of the anterior tibial artery -the only patent vessel below his umbilicus. Here to, the inflow disease appears to have spared his right popliteal artery and his left superficial femoral artery.

The only compromise with an axillary artery inflow is the amount of potential flow. In a patient with a 6-7mm axillary artery, the amount of flow going to both an arm and a leg, and a lower torso, would greatly exceed the flow capacity of that vessel. The infrarenal aorta on this man is graft and is relatively inaccessible due to the prior laparotomy for acute mesenteric ischemia, signalling the high likelihood of adhesions. The supraceliac aorta is an excellent inflow source and I have had good results dissecting it out laparoscopically as it is often deep and narrow an exposure to try to dissect open -While the retroperitoneal tunneling can be tricky, it is not insurmountable and good bypasses can result (link).

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My eye focused on the left iliac graft which perfused the internal iliac artery on that side. The graft was generous, and likely a dilated 8mm graft, and could be exposed via a left lower quadrant retroperitoneal exposure (the transplant exposure). This would allow me to to then tunnel to avoid the terribly scarred groins. On the right side, the obdurator canal could be traversed into the postioer compartment of the thigh -a graft could be sent to the below knee popliteal artery with a side graft to the tiny profunda femoral artery. On the left, the graft could be tunneled laterally near the insertion of the sartorius muscle and onto the superficial femoral artery. All of the incisions would be made in virgin skin, the only redo dissection being digging out the left iliac graft while avoiding injury to the ureter.

So I proposed a ilio-popliteal bypass. Not quite an axillo-tibial bypass, but almost there. There was some karmic balance being restored by my taking decision. It would be with PTFE all around. I quoted a 5-15% risk of major morbidity and mortality, lifelong anticoagulation, and right third toe amputation. The patient agreed.

Sketch001
sketch of iliopopliteal and iliofemoral bypassrs

The operation was done in a hybrid suite, as should all limb salvage cases. The retroperitoneal dissection was challenging because of the heavy scar tissue around the well incorporated iliac bypass, but with patience, a clampable 3cm segment was achieved. I am a big fan of Wylie hypogastric clamps because they stay out of the way when placed in a tight narrow spot, and for that same reason, I prefer the Cherry supraceliac aortic clamp. They were designed by my mentor, Ken Cherry, and his mentor, Jack Wylie for this kind of operation. A few venous bleeders were easily handled with my ring compressors (below), and I hope to continue this chain of innovation, but I digress.

park clamp.jpg
a Park clamp

The bladder was dissected off the pubis to allow the graft to be tunneled to the right pelvis. A counter incision in the right lower quadrant abdomen and a mid thigh incision mobilizins the anterior compartment muscles to the posterior compartment allowed me to tunnel across the obturator foramen. The obdurator vessels need to be avoided or there will be bleeding. this mid thigh incision allowed exposure of the profunda femoral artery more proximally and allowe the graft to be tunneled anatomically to the below knee popliteal artery for anastomosis. A jump graft was taken off this graft on the thigh to the profunda femoral artery which was small and diseased -no more than 2mm in size. An axillary bypass to this profunda would be doomed to the compromised patency rate published for ax-fem bypasses giving them a bad name. The left superficial femoral artery was exposed and provided outflow to the left iliofemoral bypass which was tunneled far laterally under the inguinal ligament to avoid the scar tissue where the common femoral artery was.

There was immediately multiphasic signal in both feet on release of clamps. After closure of all the incisions and dressings, the right middle toe was amputated.

The patient recently came back for an 8 month followup. His grafts remained patent and he was walking without limitations. Given the high quality of the inflow (large iliac graft), and the amount of decent outflow -the right popliteal and profunda, the left superficial femoral and retrograde to the profunda, gives the patients some surety of longevity for his grafts. These grafts will need lifelong surveillance.

I have since opened my mind a bit about that axillary artery to anterior tibial artery bypass. When given the choice between comfort measures for an otherwise nonambulatory but alert patient and hip disarticulation with its attendant high risk, a bypass from a large axillary artery to a large, relatively disease free anterior tibial artery is not the worst thing that could happen. For that patient, it gave them 4 more years with their family, which in any measure, is priceless. To that patient’s family, that surgeon was a savior.

The Hands of a Surgeon

Posted on by docpark

My partner, Lee Kirksey, Vice-Chair of Vascular Surgery, just got a paper on-line (link) about the curiously increasing volume of open surgical repairs we were experiencing from 2010-2014 at the Cleveland campus of the Cleveland Clinic. When I joined in 2012, my impressions at that time were mostly the paucity of straightforward EVAR cases that I had seen in private practice, and the high prevalence of stent graft explantation, infected aortic grafts, and open aortic aneurysm repairs (OAR) for juxtarenal and thoracoabdominal aortic aneurysms for nominally high risk patients. My TAAA muscles had atrophied during my years out of fellowship and I eagerly took the opportunity to recruit the help of my partners and scrub in on these cases with Pat O’Hara, Jean Kang, Dan Clair, Ezequiel Parodi, and Lee Kirksey. It is without any shame that I sought out not just extra expert hands, but interrogated these experts for different ideas and approaches, and absorbed feedback. At the time, I was ten years removed from graduation, a full-fledged vascular surgeon who thought he could do any operation put before him. I cannot imagine the thoughts churning through the head of a recent graduate faced with the choice of taking on an open aortic operation with only 5 cases under their belt, referring the case on to the regional tertiary center, or trying to McGyver an endovascular solution. I contributed probably about 35-50 cases to this paper, but the outcomes were a collective effort. Even today, I will run cases by Sean Lyden, Christopher Smolock, or Lee, if only for the company and gossip.

“We explain this distribution of cases as a function of several factors: a unique, broad regional quaternary referral practice whereby patients with complex aneurysmal disease are referred to our institution; an institutional practice evolution resulting from a critical analysis and understanding of EVAR failure modes that lead to explantation, thus generating a different perspective in the EVAR vs open decision-making process; a parallel high-risk IDE fenestrated graft study; a historical willingness to accept all physician and self-directed patient referrals (ie, a willingness to manage more complex cases); and a published expertise in the area of EVAR device explantation with an annually growing volume of commercial device removals” -from El-Arousy et al.

Reading through that paper, I have come to the conclusion that the increasing open aortic volumes at the Cleveland campus has as much to do with the ongoing retirement of experienced surgeons regionally as it does with the ability to attract these cases. Loss of these surgeons has a cascade effect like losing a species in an ecosystem. The operating rooms forget where the OMNI retractor is because nobody asks for it anymore. The ICU’s are no longer familiar with the ebb and flow of the postoperative open aortic operation. The floors lose institutional memory of the care of these vascular patients as the stent grafts and interventions go home within 48 hours, sometimes the same day.

If you were a vascular surgeon born before 1970, your approach to the scenario of the ruptured abdominal aortic aneurysm may differ substantially from that of surgeons born after the Carter administration. Most of my cohort, Gen-X and older, feel comfortable applying some betadine, opening the belly and placing a clamp. Those younger than us have told me they feel more comfortable putting up a large balloon and deploying a stent graft. In this generation, it is normal to call a general surgeon to decompress the abdominal compartment syndrome and manage the abdominal vacuum dressing. For our generation, the giant industrial robot arms and 80 inch monitors creates a barrier to the problem at hand, and gathering all the extra staff after hours and on weekends requires the logistical skills of a wedding planner.

We prefer an operating table, a willing anesthesiologist, a cooler full of O-neg blood, Prolene and a graft, strong suction, and an extra set of hands. The data suggests either method is equivalent in outcome, but I would argue that depending on the circumstance, there is an optimal method for that patient and you have to have the ability to do either open or endovascular or some hybrid combination. Unfortunately, it is clear that open vascular surgery is year over year diminishing, and and it might not be so great when we start rupturing our aneurysms.

The open approach is preferred because we got good at it by doing a lot of these cases. Your hands -it becomes natural to change the course of the disease and the fate of the patient with your hands. One of the things you lose with a wire based approach is the tactile feedback from the organ that you are treating. Yes, there is a subtle feedback from the flexible tip of a Glidewire, but that’s missing the point. The thing that is rarely considered with open surgery is the tactile aspects of operating.

Your fingers are your point of care ultrasound. As an intern, one of my earliest tasks was reaching in through a 2cm incision with my index finger, feeling for what I would describe as a rotten shrimp, and delivering it out by hooking my distal phalanx around its base. Adhesions were rubbed like money between finger and thumb to judge if you could bovie through it. If you felt a sliding sensation, it was mucosa to mucosa and you looked for another spot to cut. Into my fellowship which could be called the triple-redo, no-one else wants to do-, difficult vascular operations fellowship, the pulse or the plaque felt under the finger would guide me to carve away scar tissue from blood vessel, visualizing the feedback from the fingers. In a rupture, with the belly under a dark mire of blood, there is no seeing, only feeling. Your hands reach into the lesser sac or transverse mesocolon and strangle the aorta -your fingers while clamping, feel and avoid the caudate lobe, the NG tube in the esophagus, and split the crura of the diaphragm like a pick pocket. Once the pulse returns as anesthesia refills the tank, you scratch free the aorta with your thumb and forefinger, then slide the jaws of the aortic cross clamp over your fingers and against the spine and clamp. This takes about 60 to 90 seconds (link).

When a patient is bleeding out, this is the way to control the bleeding. In practice, no amount of rehearsing for getting a patient into a endovascular suite, getting airway and access, swinging in the industrial robot arm, and getting everyone into lead aprons, sending up wire, placing a 12F sheath and an aortic occlusion balloon, will be satisfactorily smoothly and efficiently as a STEMI or STROKE alert. The rAAA is for most hospitals, unless you are in Seattle, a once in a while occurence. Many more people can find a scalpel and an aortic clamp than they can find a 32 inch aortic balloon, a stiff exchange length wire, and a 12F sheath.

When a patient presents with a slowly bleeding, contained rupture, there is time to assemble the teams required for an endovascular repair, and for opening and decompressing the abdomen, for anesthesia to get IV’s, central lines, arterial lines, and order crossmatched blood. One has the time to get and review CT scans and choose grafts. One can even do things backwards, debranching after securing the leak (link) with a stent graft. The luxury of time should signal to you that the endovascular option is the preferable route, as all the advantages of minimally invasive repair are possible. Rural hospitals sending patients two hours by ambulance or arranging for a helicopter -this is the great filter through which those likely to survive make it into the endovascular suite. These patients do great with EVAR, because everything moves more or less like a routine elective EVAR.

The setting up the operating room for tackling rAAA is quite simple. Keep everything nearby. Nothing should ever be stored out of sight, retrievable only by arcane codes whispered in the ears of people down in the basement or across the street. Amazon gives itself a day to get that gadget to you, but the rupturing patient does not have the time to have a 28mm stent graft ordered by looking up a Lawson number, finding the materials person in the faraway room to find it, running it over a city block. The stuff has to be next to the OR. Every scenario is unique, and the best planning is assuming no one person knows where everything is but everything is close at hand -major vascular sets, retractors, C-arm, cell saver, stent grafts, open grafts, balloons, cardiopulmonary bypass -every gewgaw is few steps away. The inventory is what you see, because if you can’t grab it, it does not help the hemorrhaging patient.

If you are a vascular surgeon born after 1980, it is likely that you may have trained in a 0-5 residency and all the old people harumphing about the old ways seem biased. Rather than being rational about their awful upbringing, the old people seem to suffer from Stockholm Syndrome, turning from victims of a harsh and brutal system inherited from the original, Halsted, a cocaine addict, to willing collaborators now mooning about the good old days of every other day call and 120 hour work weeks.

There might be a growing suspicion about advocating for open surgery when fewer people can perform it. One of the truisms of surgery is if only one surgeon claims to be able to do a rare operation with great results when everyone else abandons it, like venous valve surgery or robot assisted mastectomies, it can mean that surgeon might be uniquely talented or shamelessly selling something. It is a shame that open vascular surgery is devolving into that category of arcana, like the Jedi. I have no doubt that the last open vascular surgeon will be a reclusive, bitter, wild eyed hermit like Luke Skywalker was in episode VIII, if we let it get that far.

Bald eagles were saved from extinction. The methods of species reclamation may be what is needed to save open vascular surgery. Financial metabolism drives behavior, and there must be recognition of the time and dedication required to perform good open vascular surgery in the form of increased RVUs and reimbursement. The surgeons retiring in their mid 60’s with straight backs and steady hands need to be incentivized to stay around and coach the next generation in the ways of the Jedi. Call it the master surgeon designation. Every 0-5 graduate needs to focus on getting 100 leg bypasses, 50 carotid emdarterectomy, and 25 open aortas within the first five years of practice with a master surgeon if they did not get this experience during training. Like dead Jedi, it would help even if they were just virtually present, shimmering on Facetime in their (bath)robes to go over planning and approaches, but being physically present and reimbursed for it would make the most sense.

There is always self service in any human activity. One mildly prominent vascular surgeon that I have come across is famous for saying he did not have a vascular fellowship because he did not want to train his competition. It is easy for the fifty somethings to sit and proffer their open skills and profit from its scarcity but it goes against decency to not pass on this collective body of hard won knowledge and skills. There must be stewardship of this great thing we do, this honorable and treasured endowment.

Of the concrete ways we are trying is creating a network of advanced open surgery capable surgeons regionally organized by Martin Maresch, capitalizing on social media and electronic communications. Here at CCAD we are in the organizing phase of a vascular residency, and I very fortunate to have Houssam Younes join us as he shares my interest in surgical education and open vascular surgery. We are contemplating a non-accredited fellowship. We have general surgery residents coming through our service as well as medical students.

One of my mentors told me, “I can train a monkey to do cardiac surgery,” as he was training me to do cardiac surgery. And he was right. The final comment I have is you have to demystify surgery, take away the Instagram perfection, the romance, and list in practical terms the toolkit of maneuvers that form the component parts of all operations and propagate it. Let us not kid ourselves. The technical skills of surgery can be taught to anyone. The Mayo brothers were performing surgery as teenagers before medical school. The knowledge and experience and judgement -that varies as much as people vary and we have a curriculum for that, but the physical acts of surgery need to be taught starting at the medical school level. Standardized drills and exercises need to be created so that proficiency can be metered.

“The individual per trainee OAR volume did not decrease during this period. In the training program, the use of “component separation” (separation of each
operation into discrete, instructionable steps that facilitates trainee mastery) is integral to instruction of open aortic aneurysm repair techniques and permits the
trainee to master all of the technical exposure and repair skills necessary to address and to manage both straightforward and complex aneurysm anatomy. Component
separation is essential to maximize trainee experience across all levels” –from reference 1

Here is my list of things a trainee must accomplish by the time they graduate from a vascular residency or fellowship.
1. Tying knots with gloves on with 6-0 Prolene inside a pickle jar without lifting or moving a 12 ounce lead fishing weight to which the suture is being tied, fast, one handed, two handed, left and right handed.
2. Holding forceps, needle holders, and clamps
3. Correct operation of the OMNI retractor, Weitlander retractor, Balfour retractor, Thompson retractor
4. Incise skin through dermis through correct depth and length with both #15 and #10 blade
5. Open the abdomen through midline and flank incisions and close these incisions
6. Harvest saphenous vein
7. Vascular anastomosis on a table, inside a pickle jar, inside a short Pringle’s can
8. Dissection of adhesions and scar tissue around blood vessels and organs
9. Dissect and expose the common femoral artery via vertical and oblique incisions and close these incisions
10. Dissect and expose the carotid bifurcation, left and right side, and close these incisions
11. Dissect and expose the tibial vessels in various parts of the leg and foot
12. Dissect out the brachial artery at the elbow
13. Dissect out the axillary artery and vein below the clavicle
14. Dissect out the axillary artery and vein from the axilla
15. Dissect out the subclavian artery, vein, and brachial plexus above the clavicle
16. Dissect out the arm veins
17. Dissect out the iliac artery via a lower quadrant pelvic retroperitoneal exposure
18. Dissect out the abdominal aorta via midline laparotomy
19. Dissect out the abdominal aorta via retroperitoneal approach
20. Dissect out the thoracoabdominal aorta via a thoracoabdominal exposure
21. Dissect out the popliteal artery via suprageniculate, infrageniculate incisions and prone position
22. Dissect out the inferior vena cava
23. Dissect out the iliac veins
24. Harvest deep femoral vein
25. Temporal artery biopsy
26. Endarterectomy of carotid, femoral artery, any artery with patch angioplasty
27. Exposure and control of supraceliac aorta, suprarenal aorta for clamping
28. Exposure and control of thoracic aorta
29. Exposure and control of the great vessels via sternotomy and supraclavicular incisions
30. Exposure and control of the vertebral artery
31. Safe removal of vascularized tumors
32. Amputations of digits, legs and arms up to pelvis and shoulder
33. Exposure and control of radial and ulnar arteries
34. Hand surgical techniques of exposing arteries, tendons, and nerves in forearm and hand
35. Plastic surgical techniques of skin grafting and basic rotational flaps
36. Fasciotomy of arms and legs, hands and feet.
37. Exposure and control of celiac axis
38. Exposure and control of superior mesenteric artery
39. Exposure and control of left renal vein
40. Exposure and control of hepatic veins, portal vein
41. Exposure and control of renal arteries
42. Exposure and control of profunda femoral arteries
43. Safe removal of spleen
44. Transabdominal retroperitoneal exposures of the abdominal aorta and inferior vena cava
45. All of the above in a reoperative field
46. All of the above with limited visualization and by sense of feel only
47. Laparoscopic and thoracoscopic techniques
48. Orthopaedic surgical techniques of myodesis, bone grafting, precision osteotomies, infection control, external fixation, spinal exposure
49. Safe resection and anastomosis of bowel
50. Drainage of infection
51. Intensive care of SIRS, MOFS, CHF, Septic shock, postoperative fluid shifts
52. Nonsurgical and surgical management of lymphedema, seromas, and edema
53. First rib resection
54. Spinal exposure
55. Organ harvest and transplantation
56. Planning of complex open, hybrid, and endovascular procedures

Every year, it is apparent that endovascular options suffer from some flaw when outcomes are studied beyond 2 years, but progress will march on in that sphere. It has to. The loss of open capable surgeons to early retirement is accompanied by overapplication of endovascular techniques at least partly due to the lack of knowledge of these open surgical options and achievable good results and partly due to financial incentives. The solution lies in redistribution of reimbursement to open procedures and creation of open surgical fellowships and identifying and empowering mentors who still walk among us.