Categories
AAA complications Endoleak EVAR imaging open aneurysm surgery opinion ruptured AAA Uncategorized

Off the guidelines: type II endoleak can derail the perfect EVAR

Every once in a while, I will make an exception to the SVS guidelines on AAA repair with regard to size at time of repair (link). I have a bunch of excuses. When I trained in 2000-2002 with several giants of vascular surgery, there was some controversy when the first guidelines came out in 2003 (link). The board answer became 5.5cm that year, but where I trained, it was a minority opinion held by Dr. Jeb Hallett. The majority was in the belief that as long as operative mortality was low, even high risk AAA repair could be undertaken (link). The published risk for Mayo was low, and that came from both technical excellence and high volume (more on that later). The criteria during my fellowship was 4.5cm in good risk patients for open repair based on data generated in the 1980’s and 90’s during Dr. Hollier’s tenure.

Then as now, the debate centered around the balance of risk. At specialty centers that achieved less than 1% mortality rate for elective open AAA repair, 4.5cm in good risk patients would seem perfectly reasonable. But given the 5-10% mortality seen in the Medicare database at that time for community practice, the 5.5 cm criteria was not only good science, it was prudent. The first set of guidelines held off the contentious volume recommendations that was the nidus of conflict within other surgical societies.

The advent of endovascular was a game changer -the mortality rate in the Medicare databases was 1-2% for EVAR in the community setting, meaning more surgeons in most hospitals could achieve tertiary center levels of mortality with this new technology. The issue was never really settled in my mind through the 2000’s, even with the PIVOTAL Study. I enrolled patients into the PIVOTAL Study (link) at that 4.5cm threshold during my time in Iowa. Eventually I lost equipoise and I stopped enrolling after a handful of patients. It had to do with graft durability.

Around that time, I took two patients in a row to the operating room for sac expansion without identifiable endoleak. They were Dacron and stent-based endografts placed about 5-7 years before by another surgeon and aortography failed to show type I or III endoleak. Sac growth was over a centimeter in 6 months and the aneurysm size was over 6cm in both. I chose to marsupialize the sac and oversew any leaks, with the plan to replace the graft if there was a significant leak. On opening the sac, no significant lumbar or IMA leaks were encountered but in these patients a stream of blood could be seen coming from the sutures securing the stents. It was the same graft that was in the trial, the AneuRx, and that was when I realized that these grafts have the potential to fail in the same way that patio umbrellas leak after years of use -cloth sewn to rigid metal with movement wears open the cloth wherever there is stitching. This did not happen with open repair. I lost enthusiasm for the trial as I lost faith in this graft which was retired from the market. I placed pledgetted sutures to close the leaks on both patients, and closed the aneurysm sac tightly around the graft in one patient who was higher risk, and replaced the stent graft in the other.

There are some exceptions to justify repair of 4.5-5.5cm AAA. During my time in practice, there were patients who lived far away from major medical centers who would not survive a ruptured AAA even if the rupture rate was low and who confessed they only came into town every five years or so. There were patients who suffered from clinical anxiety whose AAA was documented by a psychiatrist to amplify their anxiety. There were patients with vague abdominal pain for whom thorough workup have ruled out gastrointestinal causes and every visit to the ER triggered a CT scan to rule out AAA rupture. And there seemed to be some patients who seemed to have such perfect anatomy for EVAR, whose risks were low, and whose growth rates were so consistent that their repairs could be timed on the calendar. Some combination of these factors and lobbying on the part of the patient got them their repair in the 5cm range. And they still do.

The patient is a man in his sixties with hypertension who presented with a 4.7cm AAA which in various reports he came with described 5.2×4.7cm. After review of his images, it was clear it was 4.7cm. If measured on a typical axial cut CT scan or a horizontally oriented ultrasound probe, a cylindrical aortic aneurysm will be seen as an ellipse in cross section. A radiology report will typically report an aneurysms length and the anteroposterior and lateral dimensions. If you cut a sausage at an angle, the ovals you cut can be quite wide but the smaller length of the oval reflects the diameter of the sausage.

Looking back at his records, for three years he had multiple CT scans for abdominal  pain showing the AAA and a well documented record of growth of about 2-3mm annually -the normal growth rate. He asked me to prognosticate and so I relayed that 4.7cm in 2017 with a 3mm growth rate, we would be operating in 2020. The anatomy was favorable with a long infrarenal neck and good iliac arteries for distal seal and access. He was quite anxious as whenever he had abdominal pain, his local doctors would discuss the AAA and its risks or order a CT. After a long discussion and considerable lobbying by the patient and family, I agreed to repair his 4.7cm AAA.

The EVAR was performed percutaneously. No endoleak was detected by completion arteriography (figure). He was soon discharged and was grateful. In followup, CT scan showed excellent coverage of the proximal and distal zones and absence of type III endoleaks. There was increased density to suggest a type II leak, but his inferior mesenteric artery was not the source of it. over a three year period, his aneurysm sac continued its 2-3mm of annual growth despite the presence of the the stent graft.

While CT failed to locate this endoleak, abdominal duplex ultrasound did showing flow from a small surface vessel (duplex below, figure at beginning of post). It was not the inferior mesenteric artery which can be treated endovascularly (link) or laparoscopically (link). CT scan suggested that it was one of those anterior branch vessels that one would encounter in exposing the aorta. Usually these were higher up as accessory phrenic arteries, but these fragile vessels, larger than vasovasorum, but smaller than named aortic branches, are seen feeding the tissues of the retroperitoneum.

Ultrasound revealed the type II endoleak from an anterior retroperitoneal branch artery.

Type II endoleaks are not benign. The flow of blood into the aneurysm sac after stent graft repair is almost never benign. It is a contained hemorrhage. There are three components to the pressure signal  seen by the aortic aneurysmal wall that could trigger breakdown, remodeling, and aneurysm growth. They include pressure, heart rate, and the rate of change of pressure. The presence of fresh thrombus may play an inflammatory role. Some endoleaks clearly have a circuit and others are sacs at the terminus of their feeding vessels, never shutting down because the AAA sac can both accept and eject the blood flow. Changes in AAA sac morphology due to sac growth can cause problems with marginal seals, component separation, and component wear. Sac growth can cause pain. Ruptures, while rare, can cause death. Mostly, type II endoleaks generate more procedures because it is hard to ignore continued growth.

Review of aortogram from device implantation showed a small anterior artery arising from the proximal aortic sac (arrow)

Three years of followup showed growth of the AAA sac to 5.5cm, which ironically threshold for repair. Again, no type I or III endoleak could be seen. He reached his calculated repair date, and I discussed our options in detail.

1. Do nothing, keep following

2. Endovascular attempt

3. Open surgery, marsupialization

4. Laparoscopic ligation of target vessel

Doing nothing hasn’t worked for 3 years. What would more time buy? Endovascular -to where. The IMA is the usual target for an endovascular attempt, although iliolumbar access is possible (link), we really needed to fix this with one attempt. Open surgery is a great option -a short supraumbilical incision is all that would be needed to open the AAA sac and oversew the collaterals. The patient did not want a laparotomy. There are reports of laparoscopic guided endovascular access with endovascular coiling of the remnant sac with fluoroscopy. This adheres to the letter of the claim of minimal access, but really?

I compromised with the patient and offered laparoscopy. I have ligated the IMA a handful of times laparoscopically -these are relatively fast and straightforward cases. As I had the location of the endoleak, I felt it should be straighforward to dissect out the anterior sac much as in open repair and clip this vessel.

Use of ultrasound allowed localization of the leak and identification of the artery for clipping.

Of course, what should have been a 30 minute procedure through a minilaparotomy became a two hour enterprise getting through scar tissue (not the first time encountering this after EVAR) while pushing away retroperitoneum. I recruited the help of general surgery to get extra hands, but the patient was well aware that there was a good chance of conversion. Patience won out as the artery was ultimately clipped and endoleak no longer seen on ultrasound.

I waited a year before putting this together as I wanted CT followup. The sac stopped growing and has shrunk a bit back to 5cm or so. There will be those who argue that nothing needed to have been done about this leak as it would have stopped growing eventually, but I would counter that an aneurysm sac that kept growing like the stent graft never went in is one demanding attention. The key role of duplex ultrasound cannot be minimized. We have an excellent team of vascular scientists (their title in Europe), and postop duplex confirmed closure of the leak.

Not seeing the leak anymore is a positive, but the stent graft remains.

The patient is quite satisfied having avoided laparotomy. His hospital stay was but a few days. During my conversations with our general surgeons who are amazing laparoscopists, that this would have been a nice case with the robot. That’s a post for another day.

The definition of success in this case and many EVAR’s plagued by type II leaks leaves me wondering. Excellent marketing of the word “minimally invasive” has subtly defined laparotomy as failure, and not just in vascular surgery. When costs and efficacy are reviewed as we come out of this pandemic, I suspect that open surgery will selectively have its day in the sun. A ten blade, a retractor, a 3-0 silk is so much more cost effective than five ports and disposable instruments. And a stent graft system?

Maybe I am just a dinosaur.

Categories
acute mesenteric ischemia chronic mesenteric ischemia complications CTA hybrid technique imaging techniques Technology visceral malperfusion

Abdominal Stroke Alert!

It is a rare day that passes without the announcement of a stroke alert at CCAD. A reflex arc of activity is initiated, as time becomes the critical metric of success. Patients with strokes have a limited window of time to reverse the effects of the arterial occlusion, and the whole hospital is organized around getting the patient into the angiographic suite to open up blood vessels. If you watch it happen, it is the pinnacle of modern medicine, to achieve what only a decade ago was deemed unachievable. It was built around a foundation laid by cardiologists for heart attacks -the STEMI alert. The teams practice like racing pit crews with a stopwatch to get a patient from the emergency room, to CT scan, to angio suite. A long time ago, as a young surgeon, I had to work hard to get institutional support of ruptured AAA and cold legs. Vascular surgery has traditionally struggled to get recognition for its patients, their diseases, and its work, which is nothing less than the most important safety net for any large general multi-specialty hospital, critical infrastructure like oxygen plumbing and backup generators. As I transition to that weird designation of mid-career surgeon (please don’t call me a senior surgeon), I have also appreciated that Steve Jobs aphorism about good artists copying, great artists stealing. It’s only stealing if you don’t give credit. Here is what I borrowed from the neurologists.

Acute mesenteric ischemia is an abdominal stroke. Use it in your conversations with other people as you speed your patients way into the angio suite. The reflex arc is in there. For the emergency department, the operating room, and all the physicians, acute mesenteric ischemia sounds like tummy trouble, but abdominal stroke brings sudden clarity to conversations like:

“Well, you’re in line behind a gallbladder and a cystoscopy. Is the patient NPO?”

Me: “It’s an abdominal stroke. We literally only have a few hours before the patient dies…”

“I’ll bring the backup team in!”

The patient is a middle aged man with risk factors of NIDDM and prior history of DVT who developed severe mid-abdominal pain at 5pm. He came to the ED at around 11pm and had a general surgery consultation who ordered a CT Angiogram showing SMA occlusion (pictured below).

Acute Mesenteric Ischemia case presentation

Acute Mesenteric Ischemia case presentation (1)
Heparin was started, and at 11:30, vascular surgery was consulted. The patient had a soft, doughy texture to his abdomen, but great pain with palpation -classic pain out of proportion to the exam. Determining the patient to have acute mesenteric ischemia from a thromboembolism, I took the patient to our hybrid angiographic OR suite with the plan for arteriography, possible open thrombectomy, and exploratory laparotomy.
Arteriography from femoral access showed an occlusion of the SMA beyond the middle colic artery, a typical pattern for an embolism that occurs when embolism lodges distally and propogates proximally (image below).

Acute Mesenteric Ischemia case presentation (2)
I got Glidewire access into the ileocolic terminus of the SMA, exchanged for a Rosen wire, over which I placed an 8F sheath into the proximal SMA. This was a rather large sheath meant to catch thrombus as I suctioned it out with a 6F Penumbra catheter. This is another technique I borrowed from the neurointerventionalists. Whenever a stroke alert is going on, curiosity drives me to peak in and see what marvelous gadget or gewgaw they are using, and I was impressed by how efficiently the neurointerventionalists were able to get to the smallest thrombus in the furthest branch vessels. I was prepped for open thrombectomy, consented for bypass if necessary, but having experience in suctioning clot through single catheters and sheaths, I thought the simple design of the Penumbra and its efficacy in the cerebral system could easily translate into the mesenteric.The problem with open thrombectomy is the inability to see if you have cleared thrombus from all the branches unless you do an arteriogram after you’ve completed your procedure. This may be a significant contributor to the 20-30% bowel resection rate that occurs on second look laparotomy in my old paper and in the literature since its publication.

The Penumbra was effective in removing much of the fresh thrombus, but I was also cognizant of the fact that pulling out the catheter will draw clot into the 8F sheath that did not make it into the catheter. I placed a wire, and removed the sheath to expel much of the bulky thrombus (picture below).

Acute Mesenteric Ischemia case presentation (3)

The completion angiogram (below) doesn’t show the intermediate angiograms showing thrombus that embolized to other arteries as I manipulated the catheters and thrombectomized -I was able to successfully retrieve these with selective catheterization, another neurointerventional series of maneuvers that I have successfully borrowed.

Acute Mesenteric Ischemia case presentation (4)
After being satisfied with the completion, I removed the sheaths and explored the abdomen finding this segment of infarcted small bowel (next image).

Acute Mesenteric Ischemia case presentation (6)
There was no question in my mind that there would be some dead bowel based on the time course described by the patient. Despite my excitement about calling for GIA staplers -I am general surgery boarded- I called in the general surgeons for their help in resecting and anastomosing this segment of bowel. They would be the ones taking the patient back for any second look laparotomy, although in this patient, I determined that there would likely be no need. After the anastomosis was completed, I did a Wood’s Lamp examination (pictured), which is accomplished with a black light after giving the patient an ampule or two of Fluorescein.

Acute Mesenteric Ischemia case presentation (7)
The bowel had a splotchy fluorescence pattern which is typical of ischemia-reperfusion. This is where you have to ask the anesthesiologist and any critical care specialist who follows -no pressors please! Edema won’t kill an anastomosis as badly as ischemia will, and the gut is as sensitive to norepinephrine as are the toes. Workup in the hospital including echocardiography and CTA of the entire aorta failed to reveal a proximal source or cardiac shunts or thrombus. The patient recovered and has recently followed up, eating well, and tolerating his anticoagulation which he will be on for life.
I sent out the pictures to my neurointerventional friends with some glee, but also with the purpose of informing them that in the case that the vascular surgeons become incapacitated or quarantined due to the COVID-19 pandemic, their skills would be recruited in the care of an abdominal stroke -a blood vessel is a blood vessel.
Acute mesenteric ischemia should be the first thing on everyone’s differential of sudden onset abdominal pain because of its time dependence, yet it does not have the same resonance to the unfamiliar as abdominal stroke. Survival is dismal when too much time and intestinal death has occurred. When associated with the stroke alert concept, it translates into processes already in place throughout the hospital and it becomes natural for everyone to appreciate the urgency of treating abdominal stroke. This is the system adopted by Roussel et al. in France, where they have regionalized care of intestinal stroke. They report mortality rate of 6.9%, which is in a selected population, but significantly lower than the traditionally reported 30-60% mortality.

I am still an advocate of an open approach, especially when angiographic resources are unavailable, and every trainee needs to be able to describe the exposure of the SMA, and management of acute mesenteric ischemia. Hopefully, everyone will appreciate the urgency of all the various ischemic conditions manifest in the peripheral circulation, but rebranding them as a stroke (leg stroke, hand stroke, intestinal stroke…) is helpful. Finally, there is no survival with dead bowel -it must be found through exploration and resected.

Reference:

Roussel A, Castel Y, et al. Revascularization of acute mesenteric ischemia after creation of a dedicated multidisciplinary center. 2015 Nov;62(5):1251-6. doi: 10.1016/j.jvs.2015.06.204.

Categories
Commentary complications imaging limb salvage PAD popliteal artery entrapment syndrome techniques

Zebras, not horses: popliteal artery entrapment syndrome

mega mushroom
Adding a vascular surgeon to a hospital is like eating one of these. It turns Mario into Mega Mario. Vascular surgeons turn community hospitals into tertiary care centers.

Recalling the medical school adage, “when you hear hoofbeats, it’s probably horses, not zebras,” it is critical to think about rarities down on the differential list whenever you come across a patient. Vascular diseases suffer from inadvertent obscurantism arising from its absence from medical school curricula such that common disorders like mesenteric ischemia and critical limb threatening ischemia are frequently missed by even experienced medical practitioners. Vascular zebras are even harder to pin down because many experienced vascular specialists practice for years before they encounter, for example, adventitial cystic disease or dysphagia lusoria with a Kommerell’s diverticulum. Even so, real patients have these disorders, and we are all subject to inexperience bias -the feeling that something does not exist until you see it. You may completely miss something staring at you in the face or worse, deny its existence.

The patient is a middle aged man in his 50’s who aside from mild hypertension had no real risk factors. One day, at work, his right leg stopped working. He developed a severe calf cramp and the forefoot was numb and cool. He went to his local hospital and the doctors there appreciated the lack of pulses in the right leg and got a CTA, of which I only had the report which found a right popliteal artery occlusion.

The next morning, as he had signals and was not having rest pain, his doctors discharged the patient on clopidogrel and scheduled for angiography and stenting, per patient. As his debilitating claudication did not go away over the weekend, he came to our emergency room. While he had no rest pain, he did have minimal walking distance before his calf muscles seized up. On exam, his right foot was cool and cyanotic, with intact motor function and sensation. There was a weak monophasic posterior tibial artery signal. Bedside point of care photoplethysmography showed dampened waveforms (below).

dppg.png
Look at the blue line. The waveforms are dampened in the ischemic foot.

Because he did not bring his CT, I repeated the study. I have written extensively on the need to be able to share CTA studies without barriers. After his study, I brought it up on 3D reconstruction software.

paes.png

It clearly showed a Type II Popliteal Artery Entrapment affecting both legs (CTA images in series above). Stenting it would have failed.  I spoke with the patient about operating the next day. The plan was popliteal artery exploration and thromboendartectomy with myotomy of the congenitally errant medial head of the gastrocnemius muscle. The patient was agreeable and I took him to the operating room for a myotomy and popliteal thrombendarterectomy in the prone position. The medial head of the gastrocnemius muscle went over the  popliteal artery and inserted laterally onto the femur.

pop opened.png
Endofibrosis, cut medial head of gastrocnemius muscle to right of distal clsmp

The artery was opened and while there was fresh clot, the artery showed signs of chronic injury as evidence by endofibrosis which pealed off. Pathology showed to be fibrotic in nature.

04-SP-19-4119 Trichorme stain showing fibrous tissue as green
Trichrome stain showing chronic endofibrosis

The artery was repaired with a pericardial patch and flow restored to the tibials, not all of which were completely patent.

pop patched.png

The patient was discharged after about a week and will be scheduling repair of his contralateral popliteal artery entrapment.

The vascular surgeon has a vital role in a hospital’s medical ecosystem. One time, I heard hospital administrator say that with the advance of endovascular technologies, the vascular surgeon would become an expensive, redundant luxury easily replaced by the overlapping skillset of radiologists, cardiologists, general surgeons, trauma surgeons, cardiac surgeons, nephrologists, neurosurgeons, neurologists, podiatrists, infectious disease, and wound care specialists. When I identify these zebras, these rare diagnoses, I am neither replacing all those aforementioned specialties, nor having special insight unavailable to the uninitiated. I am keeping my eyes open. In a non-smoking, active, otherwise healthy and employed middle aged man with no cardiac history, it is very strange to have isolated popliteal occlusion with otherwise pristine arteries throughout the rest of the CT scan. That is a statistical outlier. People who occlude blood vessels in this fashion usually have more comorbidities, usually are older, and usually have more atherosclerotic disease burden. While not quite like the teenager who presented last year with the same diagnosis (after a month of misdiagnosis and delayed treatment), the cleanliness of the arteries elsewhere in the body was disturbing to me. This puts me on a zebra hunt and not the usual horse roundup.

A hospital needs vascular surgeons in the way that America need the US Marine Corps. Every decade, there is some congressional movement to see how the USMC, which has fighter jets, tanks, planes, aircraft carriers, helicopters, and riflemen, can be phased out because it seems to duplicate the services of the Navy, Air Force, and Army, and every generation a conflict proves these arguments wrong. Individuals who know things broadly and deeply, who can do many things across specialty lines, work from head to toe, and whose specialty is to customize solutions to complex problems is the special quality that is the difference between tertiary hospitals and quaternary hospitals. While these qualities are goals within Vascular Surgery, it is a generalizable goal for anyone working in healthcare. My favorite professor in medical school was Dr. Harold Neu, chair of infectious diseases at P&S. He knew everything and was interested in everything and took every moment in the hospital to increase his knowledge a little more. That’s how and why I diagnosed a case of schistosomiasis earlier this year -the upper abdominal pain was not from a coincidental aortic aneurysm, but the fellow did swim in the Nile.

I texted Dr. Sean Lyden, my former boss and partner at the Cleveland Clinic main campus, if there was any situation where an asymptomatic popliteal entrapment who had gone over 50 years of life without complications could just be watched -it was a question from the patient actually. Dr. Lyden treats popliteal entrapment weekly and maintains a clinic specializing in popliteal artery entrapment (link). One of advantages of working in vascular is that the community is small and highly accessible, and I have a group of living textbooks on speed dial (that term pegs me as antique). There is an active social network of vascular specialists and the SVS maintains SVS Connect (link) for posting and discussing difficult questions. Despite the horrible hour that he received the text (“What’s the matter? Are you in trouble?” he asked) because of the time differences between Abu Dhabi and Cleveland, he answered, “no.” Sorry, Sean, for texting you at 4 in the morning.

When you look for four leaf clovers, and you have never seen one in your life, the moment you find one must be transformative. I have never found one, but I keep my eyes open, lest I trod on one.

 

Categories
AAA Commentary common iliac artery aneurysm EVAR iliac artery aneurysm imaging open aneurysm surgery

When You Pay Your Own Way, You Chose Value

abd angio  11836788149..jpg

The patient is an active man in his 60’s with a history of hypertension who had known about a right common iliac artery aneurysm for several years and had come for an opinion. He was asymptomatic of pain. He had a prior splenic artery aneurysm embolization about a decade prior to presentation.. CT scan showed a large eccentric aneurysm arising from a retrograde chronic dissection dilating the right common iliac artery to over 4cm. This is typically iatrogenic, but impossible to know for sure. The left common iliac artery was ectatic to 2cm as was the aorta to 3 cm and all were “wavy.” This sort of tortuosity is the result of remodeling in the axis of flow resulting in lengthening of the artery and is found in those with the substrate for aneurysmal degeneration (footnote). He did not smoke and he could climb stairs without dyspnea or chest pain.

abd angio  1605093750..jpg

On examination, he was a fit middle aged man with a slight paunch. His abdomen was soft and his peripheral pulses were present and normal. Laboratory results were normal, including creatinine. EKG and echocardiogram were also normal.Treatment options were discussed in detail. The patient was paying for the operation himself and wanted to understand in detail the possible options. These included

1. Open aortobi-iliac bypass with a jump bypass to the right internal iliac artery
2. Open aortobi-iliac bypass with ligation of right internal iliac artery
3. EVAR with right external iliac extension after embolization of right internal iliac artery
4. EVAR with parallel grafts to right external and internal iliac artery (off label)
5. EVAR with iliac branched graft to right internal and external iliac artery (off label)

People are known to react with emotions and to decide typically for near term gain over far term benefits. The offer of an operation involving laparotomy and a possible weeklong hospitalization with all the attendant risks of death, heart attack, stroke, ileus, wound infection, pneumonia, organ failure and so on provides a stark contrast to the appeal of endovascular repair which can be done percutaneously, with local anesthesia, and with a short hospital stay. The lifelong CT scans are in the murky future compared to the present which is sharply in focus. This is why few people save for retirement, why profligate grasshoppers far outnumber industrious ants. In the same vein, the offer of an “advanced minimally invasive” solution plays to several cognitive biases that exists in the mind of not only the patient but the health-care provider. These include this preference for short term gain over long term gain, but also viewing all innovation as being necessarily better than what was available.

After going over the operation in great detail, the patient cut me off when I mentioned the need for lifelong followup CT scanning. Because he lives in several countries, typically, he has to pay for his healthcare out of pocket and he balked at the notion of paying for an annual CT scan. He was also disdainful of the possibility of reintervention (quoted at 10%) and having to pay for it. Also, the stent grafts, which he would have to pay for, end up being as costly as a new luxury sedan based on local pricing.

We chose open surgical repair via a midline laparotomy. An aortobi-iliac bypass was performed from proximal aorta to right internal iliac artery and left common iliac artery bifurcation with a jump bypass from the right graft branch to the right external iliac artery. Technically, this sequence was chosen for ease of access to the internal iliac artery with the external clear of graft. Operative time was 3 hours. He was in the ICU for one night. He went home after 10 days after contracting a UTI. In followup three weeks after discharge, because he had fevers, a CT scan was performed (figure). He was treated for an upper respiratory infection which cleared, and he has been doing well since. We are both happy that he will never need a followup CT scan.

Before and After

The literature supports this stance. The long term followup of the EVAR-1 Trial (Reference 1) is an example. This was the late followup of the prospective randomized study looking at open surgery versus EVAR in 1252 patients. The initial EVAR 1 findings are well known and put into question the long term benefits of EVAR as the initial mortality benefit of EVAR is lost within a few years of treatment. At a mean of 12.7 years of followup, there were more deaths from aortic aneurysm rupture and aneurysm related death in the EVAR group compared OPEN surgery (adjusted HR 5.82, p=.0064), with 13 AAA ruptures. I have mentioned before that the failure of a handful of pacemakers drove the Guidant company to recall over 20,000 of their devices. Plus, the cost of annual CT scans in the treatment group and cost of devices and cost of reintervention have driven the UK’s NICE Guidelines recommending against EVAR in elective AAA repair. The meta-analysis of EVAR-1, DREAM, OVER, and ACE trials comprising 2783 patients is confirmatory, that aneurysm related mortality was significantly higher after the initial mortality benefit of EVAR fades away, and that patients of marginal fitness gain no advantage from EVAR, particularly those with heart or renal disease, and those with PAD had lower mortality in the period of 6 months to 4 years (reference 2).

I post this case, because despite a complications, in this case UTI and URI, the patient did fine. So why is open aortic surgery considered a dying art? Why is there such pushback against the UK NICE Guidelines?During my residency in the 1990’s, in the heyday of open surgery, I observed a lot of mediocre vascular surgeons and a very few great ones. The average vascular surgeon would take 6-8 hours to perform open aortic surgery, and the patient would come out with a typical picture of oliguria, third spacing, SIRS, that would generate a 1-2 week stay that would even be described as the normal and expected course for AAA repair in surgical and critical care textbooks. The best surgeons back in the day did these operations under 3 hours with 100mL blood loss and the patients would spend a day in the ICU (often not needing it), and 3-7 days in the hospital, but they were the exception.A higher percentage of surgeons today can do EVAR well than surgeons 25 years ago could perform competent open aortic surgery. Most surgeons graduating from training rarely see or do open aortic surgery compared to the multitude of interventions. Capable open surgery basically is not available outside of a few centers, and most surgeons admit to not having equipoise to start a new trial with modern devices. Open aortic surgery is a lost art, like growing your own vegetables, dressing your own game, reading cursive script, and dialing a rotary telephone.

It is not for a lack of desire. I have several younger colleagues I have met or interacted with via social media who have an intense interest in gaining open vascular skills. They have organized open skills courses at major European vascular meetings, but I believe that is not enough.The need for exovascular fellowship, the running topic of conversation of older surgeons through the 2000’s, is never as critical as it is now as we see milennia of surgeon-years of experience retiring to golf courses and cottages. The recommendation for preferring open surgery in the younger and fitter patients is sadly out of reach for most patients and surgeons. The same passion in disseminating endovascular knowledge needs to be applied to repair the damage to vascular education by over-relying on and over-prescribing endovascular approaches.

Finally, and sadly, this patient is the exception. When given clear options and outcomes and costs, this patient made a rational decision, choosing value over convenience.

Reference
1. Lancet 2016;388: 2366-2374.
2. BJS 2017;104:166-178

Footnote:

Pearls for finding AAA:
1. Tortuosity of the internal carotid arteries including loops and hairpin turns found in patients particularly smokers implies the present of a AAA until proved otherwise
2. Palpating bounding popliteal or pedal pulses in an older smoker implies the presence of a AAA until proved otherwise. Especially if the medical student can feel these pulses.
3. African-American Females with Diabetes almost never get AAA.
4. Palpate their abdomen

Categories
imaging opinion Practice skunk works

At the Intersection of Art and Science

tube graft

I taught myself to draw during medical school when I couldn’t figure out the three dimensional relations of structures. I discovered that if you just draw the shading of an object, it pops out in three dimensions. Over the years, I took to carrying little notebooks to sketch out anatomy and proposed operations for patients through this medium. While I found this to be a handy tool that I used only occasionally, since moving to Abu Dhabi, where much of my communicating is done through an interpreter, my drawings carry a much greater weight as direct communication of my thoughts and intentions.

Sketch134215736

Drawing helps the patient and family understand the unseeable. It gives form to words that are often confused like blood vessel, graft, stent, artery, and vein.

sketch1548914407501

What is informed consent when patient’s cannot describe their problems to their friends and relatives what the problem is and what is going to be done about it?

sketch1548482196294.png

I usually draw with the pen in my shirt pocket and some copier paper, but sitting down and doing a proper sketch is soothing and very helpful for me as the surgeon to previsualize the goals that I have to reach during an operation to take the patient across the finish line. During meetings and conferences, I sketch into one of those fancy bound notebooks that I collect.

UNADJUSTEDNONRAW_thumb_4232.jpg
Funny thing is I was doodling during class as a kid, but it was spaceships, not aneurysms.

While pencil and markers do a fine job, the real magic is in using tablet based sketching software, using layers, to build serial images of the steps of an operation.

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I am increasingly tempted to use these images as my operative note, but understanding that words are needeed for billing, I comply. Even so, I find it helpful to put these illustrations on my EMR notes, because it allows everyone to see and understand what I saw and what I did. I leave you with some of my illustrations with attached comments.

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Long segment disease stents in their natural occluded state

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Our best shot

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The nutcracker

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The fractal

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Hybridized aorto-bi-iliac revascularization

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Retrieving the unretrievable embedded filter

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3 step treatment of a type II thoracoabdominal aortic aneurysm

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Dysphagia lusoria, treated

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Targets under the ulcer

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I’m not sure this really works

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An off pump CABG for a vascular surgeon

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Phase 1

Phase 2

Categories
AIOD aortoiliac occlusive disease (AIOD) BKA bypass CTA EndoRE EVAR graft infection imaging remote endarterectromy

The Unclampable: Strategies for Managing a Heavily Calcified Infrarenal Aorta

Leriche Syndrome -one of those disease names that adds to our work in a way that an ICD codes and even the “aortoiliac occlusive disease” fails to describe. When I hear someone described as having Leriche Syndrome, I think about a sad, chain smoking man, unmanned, complaining of legs that cramp up at fifty feet, pulseless.

The CT scan will occasionally show an aorta ringed by calcium in the usual places that are targetrs for clamping below and above the level of the renal arteries. Even without the circumferential calcium, a bulky posterior plaque presages the inability to safely clamp the aorta. Woe to the surgeon who blithely clamps a calcified lesion and finds that the rocky fragments have broken the aorta underneath the clamp! The first way to deal with this is to look for ways not to clamp the aorta, by planning an endovascular procedure, but circumstances may necessitate the need to control the aorta despite the unclampability.

The traditional methods of avoiding clamping the calcifed peri-renal aorta are extra-anatomic bypasses including femorofemoral bypass and axillo-femoral bypass. I propose these following options for the consideration when the patient needs a more durable solution while avoiding a heavily diseased aorta.

Not Clamping I:

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An EndoABF (actually EndoRE-ABF)

EndoABF does work to avoid clamping -these are common femoral endarterectomies supplemented by stenting of the aortoiliac segment, including in those with appropriate anatomy, a bifurcated aortic stent graft. This is often not possible to treat both sides, but one side is usually more accessible. Often, people will compromise and perform an AUI-FEM-FEM, but I have found the fem-fem bypass to be the weak link, as you are drawing flow for the lower half of the body through a diseased external iliac artery. The orientation of the proximal anastomosis is unfavorable and in the instance of highly laminar or organized flow, the bypass is vulnerable to competitive flow on the target leg, leading to thrombosis.

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AUI prior to fem-fem bypass for acute aortoiliac occlusion causing critical limb ischemia

The femorofemoral bypass is the option of patients whose options have largely run out. It is made worse when fed by an axillofemoral bypass. Sometimes, you have no choice, but in the more elective circumstance, you do.

 

Not Clamping II:

The second method is performing a aorto-uni-iliac stent graft into a conduit sewn end to end to the common iliac aftery, oversewing the distal iliac bifurcation.

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The conduit is 12mm in diameter, the key is to deliver the stent graft across the anastomosis, sealing it. The conduit is then sewn to the side of a fem-fem bypass in the pelvis, maintaining antegrade flow to both legs. The other option is to sew the conduit to a 14×7 bifurcated graft. Illustrated above is this 12mm conduit sewn end to end to the diseased common iliac artery with wire access into the aorta and a aorto-uni-iliac device. Typically, a small AUI converter (Cook, Medtronic) can be used, but the aorta is often too small even for a 24mm device, and an iliac limb with a generous sized docking segment (Gore) ending in a 12mm diameter fits nicely. Below is a CTA from such a case, where the stent graft is deployed across the anastomosis, sealing it off from anastomotic leaks (exoleaks).

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Not Clamping III:

Often, the infrarenal aorta is soft anteriorly and affected only by posterior plaque at the level of the renal arteries. While a clamp is still not entirely safe (I prefer clamping transversely in the same orientation as the plaque with a DeBakey sidewinder clamp), a balloon is possible. I do this by nicking the aorta -simple application of a finger is sufficient to stop the bleeding if you have ever poked the ascending aorta to place cardioplegia line.

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A Foley catheter is inserted and inflated. The Foley’s are more durable and resist puncture better than a large Fogarty. This is usually sufficient for control, although supraceliac control prior to doing this step is advised. The aorta can be endarterectomized and sewn to the graft quite easily with this non-clamp. conduit2.png

This has worked well, Although pictured above with an end-to end anastomosis planned, it works just as well end-to-side. I actually prefer end to side whenever possible because it preserves the occluded native vessels for future intervention in line.

The Non-Thoraco-Bi-Femoral Bypass

The typical board answer for the non-clampable aorta is taking the inflow from the thoracic aorta or from the axillary artery -neither of which are good options. The first because the patient is positioned in right lateral decubitus and tunneling is not trivial. The second because of long term durability. The supraceliac aorta, technically it is the thoracic aorta, is often spared from severe plaque and clampable. Retropancreatic tunelling is straightforward, and a 12 or 14mm straight graft can be tunelled in this fashion from the lesser sac to the infrarenal retroperitoneum. It then sewn to the supraceliac aorta and then anastomosed to a 12x6mm or 14x7mm bifurcated aorto-bifemoral bypass, of which limbs are tunneled to the groins.

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This worked very well recently, allowing a middle aged patient with severe medical problems, occluded aorta and iliac arteries, with critical limb ischemia, survive with minimal blood loss and home under 5 days. It delivers excellent flow to both legs in an antegrade fashion. Dr. Lew Schwartz gave me a list of references showing that this is not novel, but represents a rediscovery as the papers were published in the 80’s [reference], and buttresses the principle that innovations in open vascular surgery are exceedingly rare, largely because we have been preceeded by smart people. 

Conclusion: All of these come about through application of some common sense and surgical principles. The most important this is that the aorta is the best inflow source and reconstructing it with the normal forward flow of down each leg and not reversing directions as in a fem-fem bypass gives each of these options a hemodynamic advantage.

 

References for Supraceliac Aorta to Lower Extremity Bypass

  1. Surgery [Surgery] 1987 Mar; Vol. 101 (3), pp. 323-8.
  2. Annals of Vascular Surgery 1986 1(1):30-35
  3. Texas Heart Institute Journal [Tex Heart Inst J] 1984 Jun; Vol. 11 (2), pp. 188-91.
  4. Annals of Thoracic Surgery 1977 23(5):442-448
Categories
Carotid carotid-subclavian CTA imaging techniques

The Closest Thing to an Off Pump CABG -a Carotid Subclavian Bypass to Treat Unstable Angina

 

Patient is a 77 year old man with history of HTN, hyperlipidemia, former smoking, and CAD with CABGx5 and bilateral lower extremity bypasses who developed unstable angina consisting of neck and throat pain. He underwent catheterization at an outside hospital and found to have 100% LAD occlusion, a diseased, small patent left main and left circumflex (the profunda femoral artery of the heart!), 100% RCA occlusion, a patent but diseased SVG to distal RCA, and a patent LIMA graft to distal LAD but with severe plaque and near occlusion of his proximal left subclavian artery.

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He had an NSTEMI. His vitals signs stabilized in the coronary care unit and he was sent to a telemetry floor. Whenever he walked, he would get the jaw pain, and this would also occur sporadically while recumbent.

On examination, he had no left brachial pulse, only a monophonic signal there, and bounding femoral pulses where there were the origins of bilateral femoral-tibial bypasses. His radial artery pulse was diminished on the right and absent on the left. Both saphenous veins had been harvested as were arm veins for the left leg bypass.

CTA shows the left subclavian artery to be occluded at its origin.

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Heavily calcified occlusive plaque in left subclavian artery

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Arrow points to LSCA origin with plaque

Cardiac surgery, interventional cardiology, and vascular surgery were called in for consultation. Cardiology consultation (Drs. Kapadia and Shisheboor) felt, and I agreed, that the left subclavian lesion was a poor candidate for recanalization and stenting. CT Surgery (Dr. Faisal Bakaeen) and I had a long discussion regarding alternate conduits, as he had unknown radial but likely radial artery disease, and had all usable veins previously harvested. I brought up a free RIMA graft -I had worked with Dr. Daniel Swistel, in NYC as a resident, who was Dr. George Green’s protege, and as a medical student at P&S I scrubbed Dr. Green’s final cardiac case. He routinely performed bilateral ITA bypasses decades before all-arterial revascularizations were routine. I get enthusiastic talking about cardiac disease! Walking through all the options -does anyone use deep femoral vein as coronary bypass conduit -we agreed ultimately that the best option would be a carotid-subclavian bypass with plenty of backup.

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At its heart, it would be this vascular surgeon’s attempt at an off-pump single vessel CABG (above). Preparations were made with cardiac anesthesia and cardiac surgery to place an IABP (intra-aortic balloon pump) if he became unstable. For my part, the operation was straightforward, but I was going to have to go about it efficiently. I also figured that with a clamp beyond the LIMA takeoff, no significant change would occur to the coronary flow from the LIMA graft. So I hoped as I worked very deliberately. We kept him on the hypertensive side during the case.

The operation went well. The patient’s angina resolved and a followup CT showed the patent bypass feeding the LIMA and LAD.

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LIMA bypass not well visualized on coronary CTA because of the clips used in dissecting them. Perhaps we will switch to clips that are invisible to x-ray one day. 

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Composite CTA showing the bypass

His resting angina resolved. He followed up a month later and was very pleased. Moreover, he had a brachial and radial artery pulse and a general weakness of the left arm that he never complained about before lifted.

Discussion

The carotid subclavian bypass is something that really needs to be in the armamentarium of a modern vascular surgeon. Though out of print, Wylie’s Atlas (the unabridged, multivolume version) is available used through online sellers, and is useful for elucidating the anatomy which boils down to avoiding cutting the important structures -the phrenic nerve, the vagus nerve, the brachial plexus, branches of the subclavian including the vertebral artery, while cutting away muscles -lateral head of sternocleidomastoid, any part of the omohyoid, the anterior scalene muscle. And dividing the lymphatic duct if encountered. And tunneling under the jugular vein. And minding the buttery fragility of the SCA. The best technical paper out there is by Dr. Mark Morasch and it mostly deals with carotid-subclavian transposition (reference 1) but has excellent figures on bypass as well. I do both transposition and bypass, but for brevity, I prefer bypass.

This is not a unique problem, having been reported in the literature. An unusual variant of this is coronary sbuclavian steal syndrome (reference 2), which refers to reversal of flow in the LIMA bypass in the setting of subclavian artery occlusion and left arm exertion -which was not the case here, but interesting enough to mention. Here, it was a straightforward case of managing the hemodynamics. The key point of operating on such a patient was having the surety of quick response in the case of ischemic heart failure -we operated in the cardiovascular operating rooms with rows of perfusion pumps and balloon pumps and VADs and ECMOs at the ready.  Indeed, this result could not have been so straightforward and routine seeming without the combined effort and experience of the whole Heart and Vascular Institute from nursing to consultant staff.

 

Reference

  1. Morasch MD. Technique for subclavian to carotid transposition, tips, and tricks. J Vasc Surg 2009;49:251-4.
  2. Cua B et al. Review of coronary subclavian steal syndrome. J Cardiol. 2017 Apr 14. pii: S0914-5087(17)30090-4. doi: 10.1016/j.jjcc.2017.02.012. [Epub ahead of print]
Categories
AAA AIOD aortoiliac occlusive disease (AIOD) bypass Commentary EndoRE EVAR imaging kidney transplant remote endarterectromy techniques

When both iliac systems are occluded below an abdominal aortic aneurysm: hybrid techniques on the cutting edge

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AAA with iliac arterial occlusion -arrows point to right external iliac and left common iliac arterial occlusions

The patient is an 70 year old man referred for evaluation of claudication that occurred at under a block of walking. He reported no rest pain or tissue loss. He smoked heavily up to a pack a day, with congestive heart failure with an ejection fraction of 40%, prior history of myocardial infarction treated with PTCA, and pacemaker, and moderate dyspnea on exertion.

On examination, patient had a flaccid abdomen through which the AAA could be palpated, and he had no palpable femoral artery pulse bilaterally, nor anything below. He had a cardiac murmur and moderate bilateral edema. Preoperative risk evaluation placed him in the high risk category because of his heart failure, coronary artery disease, and his mild to moderate pulmonary disease.
CTA (pictured above and below) showed a 5.1cm infrarenal AAA with an hourglass shaped neck with moderate atherosclerosis in the neck, an occluded left common iliac artery with external iliac artery reconstitution via internal iliac artery collaterals, and a right external iliac artery occlusion with common femoral artery reconstitution. There was calcified right common femoral artery plaque.

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Treatment options included open surgical aortobifemoral bypass with exclusion of the AAA, total endovascular repair with some form of endo-conduit revascularization of the occluded segments of iliac artery, or a hybrid repair.

Open aortic repair in patients with heart failure and moderate COPD can be performed safely (ref 1). Dr. Hollier et al, in the golden age of open repair, reported a 5.7% mortality rate operating on 106 patients with severe category of heart, lung, kidney, or liver disease.

Typically, the hybrid repair involves sewing in a conduit to deliver the main body of a bifurcated or unibody stent graft when endovascular access is not possible. Despite techniques to stay minimally invasive -largely by staying retroperitoneal, this is not a benign procedure (ref 2). Nzara et al reviewed 15,082 patients from the NSQIP database breaking out 1% of patients who had conduit or direct puncture access.

Matched analyses of comorbidities revealed that patients requiring [conduit or direct access] had higher perioperative mortality (6.8% vs. 2.3%, P = 0.008), cardiac (4.8% vs. 1%, P = 0.004), pulmonary (8.8% vs. 3.4%, P = 0.006), and bleeding complications (10.2% vs. 4.6%, P = 0.016).

Despite these risks, I have performed AUI-FEM-FEM with good results with the modification of deploying the terminus of the stent graft across an end to end anastomosis of the conduit graft to the iliac artery (below), resulting in seal and avoiding the problems of bleeding from the usually heavily diseased artery

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Aorto-uni-iliac stent graft across end to end conduit anastomosis to fem-fem bypass

The iliac limbs of some stent graft systems will have proximal flares and can be used in a telescoping manner to create an aorto-uni-iliac (AUI) configuration in occlusive disease. The Cook RENU converter has a 22mm tall sealing zone designed for deployment inside another stent graft and would conform poorly to this kind of neck as a primary  AUI endograft which this was not designed to act as. The Endurant II AUI converter has a suprarenal stent which I preferred to avoid in this patient as the juxtarenal neck likely was aneurysmal and might require future interventions

I chose to perform a right sided common femoral cutdown and from that exposure, perform an iliofemoral remote endarterectomy of the right external iliac to common femoral artery. This in my experience is a well tolerated and highly durable procedure (personal data). Kavanagh et al (ref 3) presented their experience with iliofemoral EndoRE and shared their techniques. This would create the lumenal diameter necessary to pass an 18F sheath to deliver an endograft. I chose the Gore Excluder which would achieve seal in the hourglass shaped neck and allow for future visceral segment intervention if necessary without having a suprarenal stent in the way. I planned on managing the left common iliac artery via a percutaneous recanalization.

The patient’s right common femoral artery was exposed in the usual manner. Wire access across the occluded external iliac artery was achieved from a puncture of the common femoral artery. Remote endarterectomy (EndoRE) was performed over a wire from the common femoral artery to the external iliac artery origin (pictures below).

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External iliac to common femoral artery plaque removed with Moll ring cutter (LeMaitre Vascular) over a wire

The 18F sheath went up with minimal resistance, and the EVAR was performed in the usual manner. The left common iliac artery occlusion was managed percutaneously from a left brachial access. The stent graft on the left was terminated above the iliac bifurcation and a self expanding stent was used to extend across the iliac bifurcation which had a persistent stenosis after recanalization.

The patient recovered well and was sent home several days postprocedure. He returned a month later with healed wounds and palpable peripheral pulses. He no longer had claudication and CTA showed the aneurysm sac to have no endoleak (figures below).

post CTA EVAR-ENDORE

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Composite imaging showing normal appearing right iliofemoral segment (EIA + CFA) and patent left common iliac artery.

Discussion
I have previously posted on using EndoRE (remote endarterectomy) for both occlusive disease and as an adjunct in EVAR. Iliofemoral EndoRE has excellent patency in the short and midterm, and in my experience has superior patency compared to the femoropopliteal segment where EndoRE is traditionally used. This case illustrates both scenarios. While the common iliac artery occlusions can be expected to have acceptable patencies with percutaneous interventions, the external iliac lesions typically fail when managed percutaneously especially when the stents are extended across the inguinal ligament. The external iliac artery is quite mobile and biologically, in my opinon, behaves much as the popliteal artery and not like the common iliac. Also, the common femoral arterial plaque is contiguous with the external iliac plaque, making in my mind, imperative to clear out all the plaque rather than what can just be seen through a groin exposure.

On microscopy, the external iliac artery is restored to a normal patent artery -I have sent arterial biopsies several months after endarterectomy and the artery felt and sewed like a normal artery and had normal structure on pathology. This implies that the external iliac can be restored to a near normal status and patients that are turned down for living related donor transplantation of kidneys can become excellent recipients. In this case, this hybrid approach effectively treated his claudication but also sealed off his moderate sized AAA while not precluding future visceral segment surgery or intervention with a large suprarenal stent.

 

Reference

  1. Hollier LH et al. J Vasc Surg 1986; 3:712-7.
  2. Nzara R et al. Ann Vasc Surg. 2015 Nov;29(8):1548-53
  3. Kavanagh CM et al. J Vasc Surg 2016;64:1327-34
Categories
CTA imaging Uncategorized Venous venous aneurysm venous intervention

3D VR Images from CT Data Very Useful in Open Surgical Planning: Popliteal Venous Aneurysm

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Patient is a middle aged man with history of DVT and PE who in preoperative workup for another operation was found to have a popliteal venous aneurysm affecting his right leg. Unlike the recently posted case (link) which was fusiform, this aneurysm was saccular (CT above, duplex below). Popliteal venous aneurysms have a high risk of pulmonary embolism because: they tend to form clot in areas of sluggish flow and once loaded with clot, will eject it when compressed during knee flexion.

preop-duplex

When I perform open vascular surgery, I tend to get a CTA not just because it is minimally invasive and convenient, but because it gives important information for operative planning. The volume rendering function, which takes the 3 dimensional data set from a spiral CT scan, and creates voxels (3 dimensional pixels) of density information and creates stunning images such as the one featured on the current September 2016 issue of the Journal of Vascular Surgery. But these are not just pretty pictures.

In fact, I use these images to plan open surgery, even to the location of incisions. Vital structures are seen in 3D and injuries are avoided. Take for example the CT Venogram on the panel below. By adjusting the window level, you have first the venographic information showing the saccular popliteal venous aneurysm on the left panel, you can also see where it is in reference to the muscles in the popliteal fossa. The greater saphenous vein and varicose veins below are well seen.

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By adjusting the level, subcutaneous structures are better seen including the small saphenous vein which could be harvested to create a patch or a panel graft from a posterior approach. A final adjustment of the window level on the right shows the skin, and I can now plan the curvilinear incision.

By changing the orientation, I can also recreate the surgeon’s eye view of the leg in the prone position (below).

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And you can see how well it matches up to the actual operation shown below:

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This was treated with plication of the saccular aneurysm and unlike the fusiform aneurysm, I did not sew over a mandrill (a large 24F foley) inserted through a transverse venotomy, but rather ran a Blalock type stitch under and over a clamp.

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The several weeks postoperatively showed no further trace of the saccular aneurysm.

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The volume rendering software grew out of the 3D gaming industry. The voxel data that paints flesh and bone on skeletons and costumes and weapons is far more complex than what is applied for the 3DVR packages that are available. The images shown for this post comes from TeraRecon/Aquarius, but they are also available as open source software from Osirix, Vitrea, and various software packages sold with CT scanners. While those that are tied to the scanners are often tied to dedicated workstations -limiting you to going to Radiology and taking over their workstation, many will work in the cloud for both the DICOM data and for virtual desktop access through mobile. Contrast is not necessary if the patient has kidney dysfunction -the vessels can be manually centerlined -ie. a line can be dropped in the center of the artery to illustrate its course when viewing the VR images.

I will plan the surgery while in the clinic with the patient, actually tracing out the incisions and dissections necessary to achieve success. It is a wonderful teaching tool for trainees. But most critically, it helps me imagine the operation and its successful completion.

Categories
Aberrant right subclavian artery Carotid CTA Dysphagia lusoria imaging

Dysphagia Lusoria -a simplified approach

Arrow points to the esophagus. Tension is maintained by the tether on either side of the esophagus. By releasing one side, the tension is relieved.

The patient had been suffering with dysphagia for over a decade and had had extensive head and neck work up which found a goiter. Medical treatment of this goiter failed to relieve the lingering sensation of food getting stuck and the constant feelingof choking. It was only after a search for mediastinal sources of dysphagia that an aberrant right subclavian artery was found. 


One of the advantages of working at the Clinics (I was a fellow at the Mayo, and currently on staff the the Cleveland) is that the infrequent is common while the common is rare. Recently in clinic, I had not one but two patients with dysphagia lusoria. It was the observation of Dan Clair’s,  chairman emeritus, that by simply transposing the aberrant and yet nonaneurysmal right subclavian artery, the tension on the esophagus and trachea are relieved. Or as the dictum might go: it takes two hands to garrote someone


The question is then what to do with the stump? The natural history of the untreated stump is unknown but may be more benign than one might assume. It certainly doesn’t degenerate into an aneurysm all the time -chest CT’s are fairly common and when these are discovered, they are not usually aneurysmal like persistent sciatic arteries which present typically as aneurysms with thromboembolism. Perhaps because we don’t sit on the subclavian artery as we would on a persistent sciatic artery that these aberrant right subclavian arteries don’t degenerate. 


The old fashioned way I learned to treat these aneurysms (Kommerell Diverticula) was through a high thoracotomy and short graft repair of the aorta, replacing the origin of the diverticulum.  This is a dangerous operation for  an older, sicker, and often cachectic patient. The more recent reports involve a left carotid subclavian bypass or transposition and TEVAR after a right carotid subclavian revascularization. This second step may be unecessary if the non-aneurysmal stump proves to be benign. I don’t recommend coil embolization of the stump as mass effect of packed coils adjacent to the esophagus can cause dysphagia to recur, and this may necessitate an open resection and repair (observation, DC). 

The patient underwent a successful right carotid subclavian transposition and had immediate relief of her dysphagia for the first time in over a decade, especially because she had been told she may have been imagining the discomfort. Kudos to her physicians who ordered the CT of the chest that discovered her arch anomaly. Follow up at 6 weeks showed a stable subclavian stump and patent transposition (images above). My plan is for regular interval CT’s with increasing intervals as time passes.