At usual location. Topic renal and mesenteric vascular disease. Presenting are:
Dr. Michael O’Neil – Symplicity HTN3
Dr. Daniel Scott –Reop OR Mesenteric Ischemia CCF-Mayo
Dr. Lynsey Rangel –Open v Endo Mesenteric Ischemia
At usual location. Topic renal and mesenteric vascular disease. Presenting are:
Dr. Michael O’Neil – Symplicity HTN3
Dr. Daniel Scott –Reop OR Mesenteric Ischemia CCF-Mayo
Dr. Lynsey Rangel –Open v Endo Mesenteric Ischemia
December 15, 2015, usual place. Topic, femoropopliteal occlusive disease.
Dr. H. El-Arousy: 1-s2.0-S0741521415000646-main (Viabahn antiplatelet v anticoagulation)
Dr. J. Rowse: Circulation-2015-Krankenberg-CIRCULATIONAHA.115.017364 (Drug coated balloon v standard balloon in stent restenosis)
Dr. F. Vargas: 1-s2.0-S0735109713014149-main (1) (Drug eluting stents)
The patient had undergone EVAR for bilateral common iliac artery aneurysm with the original Gore Excluder stent graft a dozen years before with coil embolization and extension to the external iliac on the larger side and femoral to internal iliac artery bypass on the other side. A coagulopathy, one of the clotting factor deficiencies, had made him high risk for bleeding with major open surgery. His aneurysms never shrank but remained stable and without visible endoleak by CT for a long time resulting in ever longer intervals between followup.
Between 2009 and 2013, there was subtle enlargement on the embolized side without a type I or type III leak, and the patient was brought back a year and a half later, with further growth of the sac.
This was a relatively rare type IV endoleak that was causing sac enlargement due to excessive graft porosity of the original Excluder’s graft material. Its treatment is either explantation or relining. We chose to reline the graft with an Excluder aortic cuff at the top and two Excluder iliac limbs.
This was done percutaneously and in short followup, there has been stabilization and even some reduction in the aneurysm circumference.
It was long known that a certain percentage of PTFE grafts “back in the day” would sweat ultrafiltrated plasma. The relative porosity of the grafts allowed for transudation of a protein rich fluid.
This results in a hygroma formation. I remember seeing this in AV graft fistulae back in the 90’s -after flow was introduced, the grafts would start sweating! The newer grafts are lower porosity and this is seen very infrequently. Drs. Morasch and Makaroun published a paper in 2006 comparing parallel series of patients who received the original Gore Excluder (OGE), the currently available Excluder Low-Permeability Device (ELPD), and the Zenith device (ZEN). Sac enlargement occurred in equal measure between OGE and ZEN but zero was reported for the ELPD.
The ELPD had higher rates of sac shrinkage than the OGE, and equal rates of sac shrinkage compared to ZEN.
The diagnosis in my patient’s case came about through serial followup through a decade. While I doubt that the aneurysm would have ruptured in the same way as in a Type I, II, or III endoleak, I am sure it would have progressed to developing symptoms from aneurysmal distension or local pelvic compression.
Is it possible to visualize this kind of endoleak at the time it is suspected? I came across a case series from the Netherlands using Gadofosveset trisodium which takes longer to clear than the usual Gd-based MR contrasts and they successfully visualized transudative leaks in 3 serial patients with the original Excluder graft.
The problem is that Gd-based contrasts have toxicity, especially for patients with poor renal function. The protocol is time consuming. And I suspect that ten years out, a lot of grafts will have positive findings, especially cloth based grafts that are sutured to their supporting stents, without clinical basis for treatment as their sacs size are likely stable on a year to year basis.
That said, as we are well into the second decade of commercially available stent grafts, it is even more important than ever to continue lifelong followup even for what is assumed stable, patent grafts and anatomy.
The VEITH Symposium has been my favorite meeting since I was a junior resident back in the 90’s. This year is no different. I finally figured out why I like it so. VEITH is organized like the Iowa State Fair with all the charms and chaos that makes that fair one of the top 10 things to do in the US. There is the location at the Hilton Midtown which puts it in the center of all the commercial and tourist chaos that makes NY amazing. It is a high end version of the midway at the Iowa State Fair on East Side night, but instead of fried Snickers and bad teeth, you have perfectly crafted international foods and people from everywhere. Like the Iowa State Fair, everything is happening at the same time and you have to plan out your day in great detail. And there are the must sees like the debates between the giants of the field and the 20 surgeon panels sitting on stage no different from the 1000 pound pig and the handsomest cow. Then there is industry, but rather than tractors in green or blue flavors, we get seven different kinds of stent grafts at my last count. You learn how to pick out the signal from the noise, not always by counting the N of individual papers, but in the trends of the numbers of presentations that generally agree, like the hot new Fair food that catches and gets easier to buy every subsequent year. A true free market of ideas. And finally, like you can run into friends who moved to Dubuque, you run into people who were important on your life path, Jedi and Sith masters and padawans, and you have large unhealthy dinners together. What’s not to like? Next year, at VEITH!
The picture above shows a vascular anastomosis created by an ingenious gadget that has struggled to find a place in my personal kit despite performing well. It really works well when you don’t have an assistant to follow your running suture to apply tension and keep the suture out of the way. I have have come up with four reasons why I don’t use it every day even though I like the device, find it performs well, and have used it in the past.
1. Training Vascular Surgeons- The vascular anastomosis is over a century old, and the various forms it takes, interrupted suture, continuous, end to side, end to end, side to side, native to prosthetic and so on, all have to be taught so that the trainee can function even in the absence of such gadgets.
2. Cost- The cost of the device is subsumed by the hospital and ultimately the healthcare system. Using the device is the equivalent of turning the air-conditioning on when opening the window will do.
3. Time savings- If operating room time were metered like taxi time, then there might be an argument for this device, but the difference in the end is still trivial. A hand sewn anastomosis, even done slowly, takes usually no more than 20 minutes. Using this device, the times are reduced to about 1-5 minutes. This almost never is enough to make a difference, unless ischemia sensitive tissues are being repaired, but no one would use this device to sew a graft to a renal artery.
4. Results- The argument that an interrupted anastomosis is superior to a running one only works when native tissues are sewn to native tissues. A prosthetic to artery anastomosis will not adapt and frankly is the easiest to create a technically acceptable anastomosis with. An interrupted anastomosis done by hand can be done in as much time as a running one (figure below).
There are many wonderful and ingenious inventions like this. Whole specialties and institutes are built around implantation of ingenious and life saving devices. Yet the costs are increasingly astronomical and unsustainable.
Can there be innovation without sticker shock? The answer is a qualified yes. To make this a reality, there has to be several changes in the way that devices and procedures are vetted and approved. It will not be easy.
To bring a new drug to the market, the Tufts Center for the Study of Drug Development estimates in 2014 that it costs $2.5 Billion. This barrier which we have erected against ourselves insures that pharmaceutical development is channeled through a narrow group of players. On the device side, there are similar barriers and price tags to bringing a discovery to market. There is a six letter C-word to describe this situation, but it isn’t polite to use.
It used to be that breakthroughs in surgery were not directly monetizable. The carotid endarterectomy didn’t make DeBakey or Eastcott anything but fame among a small group of surgeons, but there was great good from that. A lot of time and effort and money has been used in an effort to supplant the carotid endarterectomy with carotid stenting, but the devices come at a greater cost for dubious benefit except in very particular situations. I recently performed an eversion carotid endarterectomy in about an hour’s time closing with no patch or shunt. The procedure cost the price of 6-0 suture to repair the artery, and several packs of an absorbable suture to close the skin. Add to this some disposable drapes, suction tubing, a cautery and an energy device. Compare this to a carotid stent procedure that uses a stent (4 figures), wires (up to 4 figures), protection device (4 figures), sheaths, balloons and catheters (3-4 figures), resulting in upwards of 5 figures of cost. This is for a procedure that in head to head comparisons results in a higher stroke rate, the very complication it is meant to prevent.
Health care innovation will have to have cost disruption as a necessary condition for its adoption. Whatever is used, has to drop the cost by removing a zero from the end of the price tag while yielding at least as good or better results.
The patient is a 60 year old with severe peripheral vascular disease. Risk factors included smoking, hypertension, and type I diabetes. The patient had developed gangrenous eschar over toes 1, 2, and 3. He had had prior bilateral femoropopliteal bypasses with saphenous vein, which was occluded on his symptomatic side, and stent grafts had been placed on his distal femoral to popliteal artery, but these were occluded. He also had chronic edema with some early lipodermatosclerosis and pitting edema. He was emaciated and had a low prealbumin.
CTA showed diffuse aortoiliac atherosclerosis with a severe stenosis in the proximal common femoral artery.
The femoropopliteal stent grafts were occluded but the popliteal artery reconstituted into a diseased set of tibial vessels -only the posterior tibial artery remained patent into the foot and remained as a target.
Preoperative angiography corroborated the CT findings.
The preoperative vein mapping suggested there was an acceptable anterior thigh tributary vein and marginal segments of vein below the knee. Arm vein was available as well.
My plan was to explore the veins on his legs and expose his CFA and BKPOP along with the posterior tibial artery. If the veins were inadequate, I would proceed with open endarterectomy of the common femoral artery and remote endarterectomy of the external iliac artery and stenting of the diffusely diseased common iliac artery and remote endarterectomy of the femoropopliteal segment above the stent to use as inflow for a shorter bypass with the vein we had.
Exploration showed that the anterior thigh vein was thin walled and became diminutive in the mid thigh. The infrageniculate veins were numerous and too small. I thought I might have enough for a short bypass from a recanalized mid SFA.
The remote endarterectomy of the external iliac and stenting of the common iliac went without complications. I do this over a wire to ensure access in case of rupture. A postop CTA shows the results in the aortoiliac segment.
Remote endarterectomy of the SFA went smoothly but was held up by calcified plaque above the occluded stents.
I cut down on the SFA and found that the vein from the thigh would be short. I mobilized the plaque and re engaged the Vollmer ring and was able to dissect the stents. By starting another dissection from the below knee popliteal artery, the stent was mobilized and removed.
The figure below shows the procedure angiographically. I used a tonsil clamp to remove the mobilized stents.
The common femoral and mid SFA arteriotomies were repaired with patch angioplasties. The infrageniculate popliteal arteriotomy was used as inflow to a very short reversed vein bypass with the best segment of thigh vein to a soft posterior tibial artery.
The patient had a palpable posterior tibial artery pulse at the ankle. CTA predicted the plaque found in the tibioperoneal trunk which compelled me to do the short bypass. In my experience, remote endarterectomy, sometimes with short single segment bypass, successfully restores native vessel circulation without need for lengthy multisegment arm vein bypass. Remote endarterectomy of the external iliac artery avoids the difficult CFA plaque proximal end point that often requires stenting across the ligament down to the patch. Only a single common iliac stent is required. I generally anticoagulate these patients with warfarin, especially if they are likely to resume smoking or have poor runoff. I hope to show this is the equal of multisegment vein bypass, and superior to it by virtue of avoiding long harvest incisions which are the source of much morbidity and now readmissions which are penalized.
One of the many conversations I had with Dr. PJ O’Hara, who just recently retired, was about the place of traditional open vascular surgery. It is well known that many vascular surgeons are graduating with only a handful of open aortas. The idea of creating an open vascular (exovascular) fellowship was actually floated among the society leadership, but I suspect it was mainly the kind of idea that occurs when seasoned surgeons get together for a beer. This CTA above shows the kind of aneurysm that still benefits from open repair. It is a juxtarenal AAA with a highly angulated, short neck. This was one of the cases I did in my last practice. The patient did very well and went home on POD #5. A CT was done at a later date for possible dissection (there was none) but I got to check out my work (below).
Unlike my patients who undergo EVAR, this patient won’t need intensive lifelong followup. While there is a small rate of complication in the mid and long term with open repair, these are infrequent and frankly rare. This is in contrast to the demands, often spelled out in the IFU’s, of stent grafts that require imaging and followup at 1 month, 6 month, 12 months, and annually for life. This is usually a CT scan and ultrasound, plus time and travel. While this is usually an agreeable tradeoff to most patients who are easily frightened by open aortic surgery, the cost to our healthcare system is not trivial.
The DREAM trial showed that the benefit of EVAR versus open repair is lost after a year. Most of the benefit is in the short term –in hospital stay, complication rates, and recovery time. EVAR also allows more surgeons and even nonsurgeons to treat aneurysms. Clearly, for the higher risk patients, the extra year or two of complication free life is worthwhile and avoiding possible death from open aortic surgery may be a good thing, but for the majority of patients, we still have to ask far more and far better from the technology. This starts with getting reintervention rates closer to zero and significantly diminished followup protocol printed on the IFU. It also means allowing it to cost the same as open surgery. It probably means changing the way we assess and approve medical devices.
My personal journey through the past twenty years since I started my career (I was an intern in 1994!) has been a witness to vast changes in how we treat vascular diseases. Vascular surgery was more art than science, and many fellowships were indentured servitude to a famous surgeon, usually with a fearsome reputation. There was selection pressure in the process for certain personality types – fanatically committed to received wisdom and suspicious of change. Frankly, I was not a good fit, being relatively open minded, suspicious of dogmatism, and always looking for a better way.
There was an industry sales representative back those Manhattan days. David Hunt took an interest in the peons and always brought in the best food and swag –I know this is verboten these days, but I’m talking about history here. He brought in needle holders and sutures, and trays for holding grafts for practicing anastomoses, which I did practice on those interminable weekend calls up in our Stuyvesant 10 call rooms. When you ran out of grafts, a call to Dave, and he’d bring in several bags of graft (PTFE). Clearly, the crack dealers and lobbyists didn’t have a monopoly on this sort of sales technique.
One day, he brought in stent grafts –something out of the labs, and mockups of AAA’s. My mind reeled playing with EVAR. This was the future. That fall, I pulled some favors and left work early, and got to the Hilton wearing a blazer over my scrubs. Sneaking into the Veith Symposium, I was shopping my own future. I walked around the halls laden with all kinds of stent grafts and mock ups of space age operating rooms with fluoroscopy built into them. Dodging the security, I snuck into lectures and listened to the early data, and the resounding condemnation of the angry old men. I had to be part of this. This was supercool. This was the future.
I wasn’t alone in this endo-enthusiasm. A whole generation of vascular surgeons fell into its spell. There was the urgency of training to avoid the perceived obsolescence of not being able to perform endovascular procedures. Back then, it was very difficult to get training and subsequently privileging to do endovascular. I had the great fortune of working with Dan Clair while we were at Columbia in the early 00’s.
Even back then, I also perceived a rush to cast off open surgery, even in myself. There was a thrill at crossing a long SFA occlusion with a wire. It felt like victory sparing someone a long vein bypass operation. Every year, new gadgets came along to make the crossing and opening of closed arteries slicker and easier. But the truth echoed in the condemnations of the angry old men, many who were at this point retiring en mass, was that most of these procedures weren’t very durable. Where a vein bypass would be good for years, these interventions were sometimes only good for a few months. Many practitioners, usually not vascular surgeons, vocalized that two or three of these procedures was better for the patient than any single huge operation, and (sotto voce) was better for the revenue stream. Procedural failures definitely put water on the fire, especially after the news that many of the investigators for these new devices were also investors.
Endo-enthusiasm grew into eventually a more mature perspective. Which brings me to the point of this meandering entry. I see the best results when the range of potential therapies are tailored for the needs of the patient. A frank discussion about the short, mid, and long term outcomes of any approach allows for a deliberative planning discussion that many patients, especially those who come with literature and research in hand, appreciate. This can only be possible with a practitioner who has mastered both endo and exo– vascular techniques.
I tell people who are applying for vascular surgery training that one of the best metrics for judging a program is the volume of hybrid procedures being performed. It speaks to an ease with all possible techniques and a philosophy based on imagining the best possible path for treating a patient. While there is nothing wrong with seeing programs and practices with an “open guy” or “gal” and the “wire guy” or “gal,” there will be an abundance of both endo and exo-enthusiasm, that is bias.
I believe that this secures the future of vascular surgery. Other specialties can generate unlimited number of endovascular specialists, but only vascular surgery can produce the individual who can perform a redo common femoral endarterectomy, profundaplasty, endovascular aortoiliac recanalization, and infrageniculate vein bypass to save a leg and a life. Only vascular surgery can produce the individual who can judge that with any credibility that limb salvage attempts are likely to fail and recommend primary leg amputation and rehab and have the patient walking on a modern prosthetic limb within a month, and maybe even running within a year. And that same surgeon can perform a tibial intervention to heal an ulcer, and understand that it only needs to stay open 6-12 months and forebear reintervention when the artery is closed and the patient healed and asymptomatic.
So I head to the VEITH symposium looking forward to seeing what’s next. I have a badge this time.
JULY 30, 2008 10:55 PM
Group I: small tumors, minimal attachment to carotid vessels, easily resected
Group II: larger with moderate vascular attachments
Group III: large tumors encasing carotid artery, often requiring resection of tumor and carotid artery
This was in contrast to what I was taught as a resident in New York City, that carotid body tumors were once a decade or career occurrence. Most of the cases found in my practice at that time were diagnosed by ultrasound, often on carotid screening. No one knows why they cluster in the prairie.
The case in the top movie had bilateral tumors; this occurs in 5%. The bottom movie shows a highly vascularized lesion with a branch coming from the external carotid.
This was embolized on the morning of surgery [figure below], and the tumor was avascular and shrivelled up at extraction.
Generally they are not malignant but are characterized by steady growth, mass effect, and eventual unresectability. Some are malignant and will metastasize, generally to lymph nodes. It is believed that malignant carotid body tumors are in the minority.
The use of embolization in larger tumors is a topic that has its proponents and detractors. I have found it useful in larger tumors, but unnecessary in the smaller ones. There is some risk to the patient and these can be technically challenging cases for the neuroradiologists, as these tumors take multiple sources from both internal and external carotid arteries.
The usual situation is a multiple redo or infected groin with heavy scarring. Woody is the proper adjective. The common femoral artery may be obliterated or buried in the scar but a small profunda or its major branch may be accessible. Or you just run into it and get bleeding. Rather than bemoan your fate, you may be able to make a purse out of sow’s ear by exposing the artery and sliding in an appropriately sized Argyll shunt. Backbleeding into the shunt means that you haven’t dissected (hopefully) the artery, and now you have control over the surface edge of an artery. You can then clamp the shunt. You can assess your situation and decide that spending another two hours digging out two centimeters of 3mm artery may not be worthwhile, but you also decide that it is important to preserve this vessel.
It is straightforward to anastomose graft to the arterial stump. The shunt keeps you from narrowing the anastomosis, as you are well aware from carotid shunting. While you are doing this, if you have a Rummel tourniquet or vessel loop around the distal external iliac, you can feed the leg via this shunt as long as you remember to have the graft over the shunt. And remove it when you are done.
Another scenario is in revascularizing an intercostal, lumbar artery, or backbleeding posterior origin accessor renal but don’t want to do it right away.