From Dr. Dmitirios Virvilis, formerly my trainee, now my colleague, who had this interesting case of end-stage iatrogenic pseudoaneurysm.
85-year-old gentleman with history of atrial fibrillation on anticoagulation, mechanical valve on Coumadin presented to our emergency department with significant hemorrhaging from the right groin (figure above). The patient had a coronary angiogram 2 months earlier done elsewhere complicated by a pseudoaneurysm which was managed with ultrasound guided thrombin injection that was not successful. Patient was sent to a vascular surgeon at another facility and the decision was made to intervene with the placement of a covered stent on the common femoral artery (possibly due to high patient risk?) compromising the junction of the SFA and profunda artery. The patient developed a large hematoma following placement of the covered stent and was managed solely with antibiotics for over a month prior to presentation.
On physical examination, the patient was septic, lethargic with grossly infected groin (image above). A CT scan with contrast was performed which showed active extravasation with stranding around the femoral vessels (below).
The patient was taken emergently into the operating room. Due to the extent of the infection under the inguinal ligament I obtained proximal control by performing a retroperitoneal flank incision. The iliac vessels were controlled and then I proceed with exploration of the hematoma. The junction of the superficial femoral artery and the profunda artery was separated and the common femoral artery was liquefied. There was only a very thin posterior layer of the common femoral artery and the cover stent was floating in the hematoma. The wound was thoroughly debrided. The distal external iliac artery was transected and the stent was removed. The junction of the superficial femoral artery and profunda artery were separated. A Rifampin soaked graft was used (picture below), which was an 8mm gelatin impregnated Dacron graft soaked in Rifampin (600mg in 200mL of saline) for 20 minutes.
The graft was anastomosed to the common iliac artery to fully exclude the external iliac artery which was debrided and ligated. The profunda artery was reimplanted on the side of the graft in an end-to-side fashion. After the wound was thoroughly irrigated and the graft was covered . The muscle flap was created in the usual fashion with lateral mobilization preserving the medial vascular pedicle. The wound was partially approximated and the top of the wound was left open for an application of wound VAC (below). The fact that I am practicing in a remote area has made me to be more efficient and incorporate in my practice many procedures picked up through training that fall under general surgery, plastic surgery, and advanced vascular surgery.
Patient remained hemodynamically stable and recovered in the ICU for 48 hours. After hospital course of approximately 5 days was finally discharged to rehabilitation center. Patient was seen 1 month and 2 months after the first operation and has had completely healed incision (below). There is a strong femoral pulse on the right groin with multiphasic pedal signals. Patient has completed 8 weeks of IV antibiotics. I am planning to perform a CT angio with runoff in the next few months in order to evaluate my distal anastomosis because I am concerned about the Pseudomonas that grew from the OR cultures.
From technical standpoint there is 2 things that I would like to address:
#1: The textbook answer would be to perform a bypass with a native conduit with deep femoral vein or great saphenous vein, but this is difficult to perform efficiently solo. I do not have CryoVein on the shelf and the cost of such a conduit is prohibitive in my institution. And extra-anatomic bypass also on the lateral approach, an obturator bypass, adds time and complexity especially with the separation of profunda and superficialis.
#2 Next time I will have to perform a bypass like that I will probably perform the bypass first to the profunda artery and then reimplant the SFA which is more mobile.
Discussion by W. Michael Park, MD
I have to congratulate Dr. Virvilis on this nice outcome. I agree on remaining vigilant for late re-emergence of infection, but it is very unlikely to occur as time passes without signs and symptoms. I have three things to add. First is that Rifampin soaked graft is effective in revascularizing within a decontaminated field while sewing to uninfected artery. Taking the graft to the common iliac bifurcation which was exposed to gain proximal control was wise as anastomoses to the external iliac under the inguinal ligament are challenging and there was an unknown degree of infection here. Second is the sartorius muscle flap must be in the armamentarium of every vascular surgeon and is an easy jumpoff point to learning gracilis and rectus femoris flaps as well. The lateral mobilization and medial rotation is done preserving the medial arteries that feed the graft -dividing too many of these to mobilize the flap kills the flap. The flap delivers the immune cells and vascularity to clear the remnants of infection and forms a better granulation source bed than debrided, infected wound.
Finally, Dr. Virvilis did reach out to me from around the planet (I work in Abu Dhabi, he in Mississippi) for a run through of his plan. I cannot tell you how valuable this is to be able to bounce ideas off of someone you trust. When I graduated from my fellowship, Tom Bower put his hand on my shoulder and said, “Do not hesitate to call me if you have a difficult situation.” I have since grown a long short-list of mentors, friends, and partners on speed dial. It taps me into cumulative millennia of surgeon-years of experience. With social media and increasing acceptance of its use to share ideas, there is absolutely no reason to work in isolation.
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.
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.
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.
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
A body floating in space, a fetus in the womb, a dad lounging in his favorite chair, share the feature of weightlessness and represent the absolute neutral position (figure above) of the human which is the position of a relaxed supine quadruped -a dead mouse. Anything else is a stress position, including standing. Repeating motions outside of this relaxed pose or holding those positions away from this absolute neutral for long periods of time is a nidus for injury and pain. That is why most land animals sleep flat on the ground.
The Pain Operations
Operations to relieve pain are often the most gratifying to both patient and surgeon to perform successfully. This circumstance applies to the commonly performed procedures such as spine surgery, endometrial ablations, and varicose vein resections. When the pain is due to a rare set of circumstances, things are not so easy. Typically for rarer pain syndromes, two things need to coincide for the successful operation to happen. First is the patient must suffer while more common and potentially life threatening diseases are ruled out and even treated if these are found. This may take months or years. The second necessary condition is finding a physician who has seen the particular pain syndrome before and understand how to test for it and treat it. That meant the majority of people never get treated, or are shunted into the circle of shame as malingering, drug seeking, and mentally unstable. The opioid epidemic creates double jeopardy for these patients -they can become addicts as their pain is never successfully diagnosed and treated and they get labeled as drug seeking.
All pain syndromes that can be successfully treated share common features that give you a degree of surety about the diagnosis, but at the end, there is a leap of faith on the part of both patient and practitioner because many of these operations have a failure rate ranging from 5-20 percent. First, the symptoms must be associated with sensory nerves, somatic or visceral. Second, there is a physical mechanism for that nerve to be inflamed from compression, swelling, or irritation that can be accounted for through history, physical examination, and imaging studies. Third, though not a constant, a major nerve trunk will be associated with a blood vessel, typically and artery, that is also affected by compression. Fourth, when swollen veins are the cause of pain, it has to be recognized that at an end stage the organ that the veins drain can also be affected.
The Pain Must Have a Testable Anatomic Basis
The somatic sensory nerves in the periphery are well mapped out and known since even classical times. The described pain should be consistent with a nerve. The best and easiest example is a neuroma that forms in an amputation stump. It triggers pain in its former distribution. It is palpable as a nodular mass. It is visible under ultrasound or cross sectional imaging. And it is easy to turn off temporarily with an injection of lidocaine, either under palpation or image guidance. If you can turn off the nerve and relieve the pain, it is likely that ablating or relieving the nerve of irritation will also relieve the pain. Such is the case in median arcuate ligament syndrome (figure below). The celiac plexus is caught under the median arcuate ligament and compressed. It causes a neuropathy that is felt in its visceral sensory distribution and the brain interprets these signals in the typical ways irritation of the stomach is interpreted -as pain, burning, nausea, sensations of bloating, and general malaise. These nerves can be turned off with a celiac plexus block and the effects tested by giving the patient a sandwich. When it works, the patient will say they will have had relief for the first time in years and operation to relieve the ligament compression and ablate the nerve can proceed. Same for many of the diseases listed.
Tight Spaces Impinging Nerves, Arteries, and Veins
Many of the tight spaces involving the nerves have accompanying arteries that are compressed. This results in injury to the artery in the form of intimal hyperplasia, post stenotic dilatation, aneurysm formation, and thromboembolism. Shared tight spaces that cause problems for nerves and arteries have the common features of fixed ligaments, adjacent bones and muscles, inflammation, and motion. These include the thoracic outlet, antecubital fossa, cubital canal, diaphragmatic hiatus at median arcuate ligament, inguinal ligament, popliteal fossa, carpal tunnel, obturator canal, mediastinum, retroperitoneum -basically anywhere nerve, compression, and motion occur. In some instances of median arcuate ligament syndrome, postures and breathing trigger the pain. Holding a child in an arm may trigger pain in neurogenic thoracic outlet. Or sitting while wearing tight jeans may trigger a burning pain in meralgia paresthetica. It is not uncommon to find damaged arteries in median arcuate ligament syndrome, thoracic outlet syndrome, and popliteal entrapment or thrombosed veins in nutcracker syndrome, May-Thurner Syndrome, and Paget-von Schroetter Syndrome. Because nerves are typically difficult to visualize, their compression may only be inferred by testing for compression in their adjacent arteries.
Dilated Veins and Swollen Organs and Visceral Pain
Venous hypertension is most commonly conceived of as varicose and spider veins of the legs and offer a model of pain when applied to other pain caused by venous dissension. The visceral sensory fibers veins and arteries trigger a very intense pain that localizes to the trigger. I have often witnessed this when I manipulate a blood vessel during local anesthesia cases. Visceral pain from swelling has a dull achiness that is localizable to my spider veins after a long day standing like a bruise (below). The swelling from varicoceles which I have also had feel nothing less than feeling the aftereffects of getting a kick in the balls -not the immediate sharp pain but imagine about 5 minutes after with the mild nausea, abdominal discomfort and desire not to move too much, and even a little flank pain. Imagine this occurring low in the pelvis with ovarian vein varices in pelvic congestion syndrome. This kind of swollen gonad pain afflicts many women whose pain is so frequently dismissed by male physicians because they have no context -well imagine getting kicked in the balls hard, wait about 5 minutes and that moment stretch it out to whenever you stand for a long period of time (below).
When a limb is swollen from a thrombosis, the veins hurt and is similar to a bone pain from a fracture or a pulled muscle -that is how the brain processes the pain, but when the muscles and skin get tight from edema, the pain is sharp and dire. This is the same kind for pain from a distended left kidney from nutcracker syndrome or a spleen from a splenic vein thrombosis. These conditions can be modeled and predicted based on history and correct differential and confirmed with proper imaging -always.
Build a theory of the pain based on a testable proposition and set of nerves
That is the final message. These pain syndrome require some imagination and empathy to map and model. Predictive tests then can be performed on physical examination, functional testing, or imaging. Often, the adjacent artery is the only thing that can be reliably visualized and tested, knowing that it is the nerve that is compressed. Turning off the offending nerve with a block and relieving the pain is the most powerful argument for operating. It is building the argument for an operation that requires these objective data, but at the end, it does require some experience and faith. You have to believe in your patient and the science and when they coincide, you have to act.
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.
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.
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?
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.
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.
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.
I got a call about a graft fistula that had a stenosis. “Where?” I asked. At the arterial anastomosis, the velocities were high -500cm/s. My next question was, “is there a problem with dialysis?” The response was, “no.” I reassured the caller and then asked what the velocities were in the mid graft. Around 200cm/s.
Which made me pull out a sheet of paper to do some math. I have to confess, after learning higher level math and fluid flow during college, I had to think about it. The question was, for a pipe that goes from 4mm to 7mm in diameter, what is the ratio of velocities in the smaller pipe compared to the larger section?
The diagram above shows the calculations. This makes a lot of assumptions about the fluid that aren’t necessarily true but I went to medical school, not grad school.
The algebra comes out to the calculation that the velocity in the 4mm segment will be 3 times faster than in the 7mm segment. Which is pretty close.
At the end of all this, it struck me that I needed no other more relevant information than the answer to, “is the dialysis going well?” The velocity numbers for the proximal anastomosis aren’t helpful except under the condition “yes, there is a problem with dialysis.”
There is only the Boolean, Dialysis Good, true or false. Enough flow? implies we know the exact number, a magic volume flow number. The problem with focusing on flow is that there is a problem with too much flow. Arteriovenous shunts are like adult ventriculoseptal shunts (VSD). They burden both sides of the heart. It’s like hitching a trailer on a car. Some cars like SUVs are fine for this, but imagine hitching a boat on a tiny car, which what happens to patients with bad hearts and renal failure.
We don’t have many good options in heart failure or severe systemic atherosclerosis than a catheter. Catheters are just awful, but in heart failure, any amount of flow may be detrimental.
I recently saw a patient with no fistula flow, but a patent and aneurysmal segment of cephalic vein fistula remained and inflated with expiration (above). The outside hospital had placed a tunneled catheter in the right internal jugular vein, but it failed to draw enough blood and they had taken to accessing the cephalic vein with a 14g needle and returning the dialyzed blood via the catheter. Here is a case of the nonflow access. The fistula has gone down at the anastomosis several months before -this is rare to have both a widely patent cephalic vein and a closed anastomosis.
The draw from the vein worked well because there was a siphon to the right atrium and on dialysis days, she was fluid overloaded enough to keep the remnant cephalic vein inflated.
The lack of arterial flow meant that return couldn’t happen in the same vein, but imagine if she had the same in the other arm or better, on the thigh.
Which then made me think that a dilated and varicose thigh vein with a patient sitting slightly upright would be fine for access. Why not? And accordingly, in heart failure patients, high venous pressures are the norm especially in the legs when the head is up. Can we make an access for heart failure patients that takes advantage of their fluid overload?
It would work like this. In both thighs, the valves in the saphenous vein are cut using a endoluminal valvulotome, particularly the anterior thigh tributary. Then you wait. The combination of heart failure and bipedalism will result in huge veins. Once the veins are huge, you could make a very small fistulous anastomosis, but I don’t think it would be necessary.
Some people will have large superficial veins that will allow for dialysis access even without a fistula. Crude drawing below if dilated veins created on the thigh.
An oldie but a goodie from my first blog, “The Pipes Are Calling” on Medscape. This case came to mind when I recently diagnosed a pheochromacytoma from my clinic -middle aged man with difficult to control hypertension and unilateral renal artery stenosis. One of the most critical lessons learned from medical school, the Columbia University College of Physicians and Surgeons, was to be a complete physician, to be curious and engaged in the well being of your patient even outside the narrow focus of your specialty. This I learned especially from people like Drs. Harold Neu and Mark Hardy.
W. Michael Park, MD, Surgery, Vascular, 05:24PM Jun 23, 2010
The patient is a middle aged man who developed rest pain of his left leg after CABG for 3VCAD/MI. Workup revealed an occluded left iliac arterial system with diffuse atherosclerosis of his aorta and iliac arteries. He had a long history of bilateral calf claudication and his right SFA was occluded and his left SFA was diffusely diseased. CTA was performed and showed the described anatomy
And a “2.2cm peripherally enhancing mass” probably representing a lymph node with central necrosis, adjacent to the aorta.
I proceeded with aorto-right iliac and left femoral bypass, planning on later leg revascularization as needed after establishing inflow. During the retroperitoneal dissection over the aorta, I ran into this purplish mass and on manipulation, the patient’s blood pressure shot to 210mmHg. As my brain processed, my resident who had just finished reading his chapter on endocrine, said, “this could be a pheochromocytoma.”
That tumor was out quicker than you could say “snit.” Frozen section, and later final pathology returned paraganglionoma.
The patient recovered well and graciously gave permission, as all my patients here do, to allow this to be discussed. He noted that hypertension kept him out of Vietnam. Records showed an uneventful CABG.
Applying the retrospectocsope, I will now be far more wary of midline retroperitoneal lesions that are highly vascularizad.
Innovating Our Way Out of Not Having Enough Vascular Surgeons
This year’s SVS meeting featured a sobering assessment about the vascular manpower deficit affecting North America at the E. Stanley Crawford Critical Issues Forum, moderated by Dr. Michel Makaroun, MD, president-elect of the SVS. 35-45% of practicing vascular surgeons plan on retiring in the next decade by conservative estimates. We are not attracting enough candidates for the training programs. The solutions, including decreasing the length of training, public relations campaigns, and incentivizing retention have had mixed results, but we have yet to see a sustainable rise in vascular surgeon numbers.
Burnout driven by lack of work-life balance, the advent of electronic medical records optimized for billing, the passing of the private practice era, and the constant need to adapt to new techniques, create a persistent downdraft on staffing. So as some hospital face the reality of having to contract services, little attention is given to delivering best care with the staffing that we have. Changing how we practice is the only viable solution.
There are an estimated 3000 active vascular surgeons in the US. Imagine if all the cheese needs of this country could only be met by 3000 artisanal cheesemakers who make cheeses one at a time and want to live in places with international airports, BMW dealerships, and major league sports teams, and must have 3-4 partners to share cheese call. If you are a rural hospital in dire need of vascular surgery services and your one vascular surgeon is retiring, you are probably SOL.
When I was training, vascular surgery was oft touted as a primary care specialty. And that is how many of us still practice, managing risk factors, monitoring mild disease, as well as planning and performing interventions and operations. As much as I enjoy that kind of interaction, the half hour to an hour visit for a head to toe cardiovascular survey and discussion, educating patients and families about pipes and pumps, is incredibly inefficient. A healthcare system, a hospital, facing a staffing shortfall, has to do everything possible keep that vascular surgeon in the OR during work hours.
What is the core function of a vascular surgeon? Making good decisions and executing plans well. Decisions require data. What is this data? We laud the history and physical examination, but this is a throwback to another era. If you look at the diagnosis of myocardial infarction, it is not standard practice for a cardiologist to come and get a history, examine the patient, and declare that the patient is having a heart attack based solely on history and physical examination. It is a triage nurse in the ED who draws labs and orders an EKG which is read by a machine. These data points will tell you if heart muscle is being damaged. A process is started which triggers a team to come and take care of this patient. The hospitals focused on this actually drill their cath lab teams like pit crews. A stopwatch starts with the goal of revascularization under an hour.
Not so with peripheral vascular disease. The ischemic foot might have only a few hours depending on its presentation before it is irretrievably lost, but no matter -they sit in the ED until a vascular surgeon comes to speak to the patient and family, examine them, and then order tests, admission, consults, and operating room -typically all by themselves. Getting these patients into the operating room is in many places hampered by the lack of dedicated OR staffing, radiology techs, anesthesiologists, space, equipment, and critical care capacity. During work hours, there are scheduled cases that have to be delayed or canceled for another time, which takes time to do. After hours, the patient may have too many comorbidities to handle safely with the available staff. The vascular surgeon may have to bargain and cajole, to align several factions whose attention is demanded by many equally important concerns. If you decide to hold a lavish dinner party of twenty important guests -reserving space, calling caterers, inviting guests, arranging transportation – on short notice, you might pull it off once, but if you do this regularly, you are a masochist of the first order.
In the heart attack model, the history and physical examination is relegated to a series of yes/no or how long questions, and positive responses trigger a series of coordinated actions of a system -a reflex. In the leg attack model, there is no such system. I have to blame the vascular surgeons for preserving the current model. Vascular surgeons are organized as a guild. Guilds are protective of their monopolies on skills and markets and fiercely resist change. Most vascular surgeons are terrified by loss of control, and cling to the notion of being misunderstood and unappreciated saviors. We can do better.
The area that needs streamlining is at the point of referral. The majority of time of a vascular surgeon is spent working up normal blood vessels, varicose and spider veins, leg edema and pain, and mild and moderate arterial atherosclerosis. This work initially does not require a vascular surgeon but rather a focused set of policies and initial diagnostic studies that can be administered or ordered by any caregiver. Reducing the need for vascular surgeons at this point in vascular care will go a long way in extending the vascular work force at hand.
Point of Care Blood Flow Evaluation
Finding and declaring blood vessels to be normal is challenging and too often time consuming. Streamlining this will go a long way in freeing vascular surgeons to take care of disease.
The average caregiver is an inconsistent pulse taker. The palpable pulses are not always easy to find. Asking over the phone or as policy for someone to examine pedal pulses -the posterior tibial artery and dorsalis pedis artery pulses, is challenging. A positive is just as likely to be true or false as a negative. No cardiologist would ask a similarly detailed and technical question about an MI. In fact, they can’t ask, “Is there a pulse in the LAD?” Cardiologists make do with tests easy to obtain and interpret with certainty -the plasma troponin level and the EKG. The EKG is read by an algorithm so established and so tested, that it should stand as an example of early machine intelligence taking over a human job -but I digress.
What is our EKG? It is not the ABI -the ankle brachial index, because it is terrible at identifying disease, and is difficult to obtain reliably without practice. The closest thing to an EKG we have in terms of simplicity and accuracy is the pulse volume recording, the PVR (figure below). A FloLab machine, the machine used to obtain PVRs, will basically run itself once the cuffs are correctly applied on the leg, and the tracings are very easy to interpret. Unlike an EKG, there are no electrodes whose locations you must memorize. If the closest vascular surgeon is an hour away by ambulance, the transfer of a patient with flat waveforms and ischemic foot does not require a consultation on site. The patient would go to the vascular surgeon with no time wasted and no kidneys injured by CTA’s that too often fail to travel with the patient. Unlike an EKG which can be performed by many caregivers, a PVR requires both the equipment and a vascular technologist. A vascular technologist is not available 24-7 in most hospitals, and FloLab machines purchased for vascular labs are not meant to be dragged around the hospital.
So let’s think out of the box about another box in every triage nurse’s cell, every ER and ICU bed, and on every hospital nursing floor. These are pulse oximeters with a digital tracing, and bonus points, some come with strip printers! Placing a pulse oximeter probe on the second toe and comparing to an erstwhile normal wave signal such as on an index finger can provide qualitative information about normality and disease. Normal waveforms and abnormal ones can be easily discerned. A flat line is another obvious finding when in comparison, a finger or an ear on the same patient has normal signals.
How much better would a vascular surgeon feel about a transfer call that has this information, “digital waveforms are flat in this patient with rest pain and a bruised toe.” How much better would a vascular surgeon feel about a call about a patient with “digital wave forms are normal in this patient with toe pain and a bruised toe. We got an x-ray and there was a fracture.” The communication can be quite detailed and refined. For example: “The patient had no pulses, we think. Digital wave forms were dampened but pulsatile in a patient with a bruised toe, we’ll send to vascular clinic in the morning.”
A study comparing pulse oximetry signals and ABI in type 2 Diabetes Mellitus found the following results (link).[i]
These data suggests pulse oximetry signal is equal to and somewhat better than ABI. Why is this important? Cost. This information is better than asking unsure people, “Is there a pulse?” A vascular technologist need not be on call 24/7. Extra FloLabs for ED, ICU, and floors need not be purchased. The pulse oximeter with waveform tracing is nearly ubiquitous wherever patient’s oxygenation needs to be assessed in most hospitals. While not perfect, it has great potential for serving as vascular surgery’s EKG machine for critical limb ischemia. Policies and algorithms can be built out in collaboration with Emergency Departments and nursing departments that can effectively determine if blood flow is normal or abnormal at point of care. Effective emergency responses to critical limb ischemia can be authored triggered by abnormal findings. Acute limb ischemia protocols based on time sensitive responses can be initiated. All of these can flow from referring entities being able to determine objectively normal or abnormal blood flow.
The vascular clinic is a sorting process where patients are determined to be normal or have mild, moderate, or severe disease. The vast majority of the time spent in clinic can be spent in triage by trained nurses and testing by technologists. Clear pathways and guidelines can dictate the ordering of vascular laboratory tests obviating the need for vascular consultation at this stage. Patients with normal blood vessels and vascular function are sent back to their physicians with the normal report. Patients with mild disease and moderate disease are sent to a physician with specialization in cardiovascular medicine for management of risk factors and periodic surveillance. At any point in the process, a vascular surgeon can be called to provide guidance and direct patients to different tests and consultations. The patients needing operations, based on correct indications and imaging are sent to a focused clinic where the surgeon and interventional team can review films, determine the urgency of indications balanced against risk, and plan and schedule procedures. Currently, vascular surgeons do all of this by themselves, as well as make hospital rounds, perform procedures, and interpret vascular laboratory studies, seeing one patient at a time.
In introductory computer sciences courses, search algorithms are taught to be brute force if you look at one item at a time for the thing you want, and to be efficient if you have presorted those items because every time you look, you can exclude part of the data set, ever shrinking the pool in which you search, making the search shorter and faster
The shortfalls in vascular surgeon numbers have as much to do with this dependence on the star chef cooking up one meal at a time, rather than a team working off recipes, with the chef directing the flow and occasionally jumping by the fire to make the most difficult of dishes. The first restaurant can seat three parties. The latter, easily ten times the number. Everyone gets fed.
Only asking how many vascular surgeons you need misses the big picture because there are many equally important questions. How many vascular technologists do you need? An accredited laboratory provides the critical diagnostics upon which decisions are made, and the surgeon should oversee but not be directly involved in the initial screening. Nurses trained to triage and order vascular laboratory tests and even perform the simpler ones is the second need. Third, is the cardiovascular medicine physician who manages those patients discovered to have mild to moderate disease, and depending on symptoms, refers severely symptomatic moderate disease and severe disease to a scheduling clinic. The scheduling clinic is composed of both interventionalists and vascular surgeons who plan interventions and operations.
Surgeons must be in the operating room to be effective. A well thought out and organized system, with interlocking teams, and well disseminated basic knowledge and awareness of vascular diseases reduces the need for a vascular surgeon to be present all the time in many places and ultimately increases the effectiveness of the vascular surgeons that are available by keeping them in the operating room. The system needs to be set up by the surgeon to allow clinic to be a setting mostly for consenting the patient for an operation or a discussion of treatment options.
Finally, vascular surgeons must be aligned with all the resources of the hospital including the considerable numbers of interventional cardiologists and radiologists, neurologists, and nephrologists. There is no reason someone should wait a month to get on the OR list for an iliac angioplasty and stent if an equally skilled and privileged cardiologist or radiologist has an opening the next day. The surgeon’s special talent should be open surgery and hybrid surgery -that which mixes open surgery and intervention in optimal measures which is not possible from a purely percutaneous approach. The key is frequent and easy communication between specialities and trust built by being in one shared cardiovascular institute.
There is a critical need of good operators. The acuity of disease and their solutions demand the continued presence and availability of open surgery. The fact is, many solutions are optimal in a hybrid fashion and for peripheral vascular disease, these options can only be offered via a vascular surgeon trained in both open surgery and peripheral interventions, or in a combined effort of open surgeon and interventionalist. And many disease categories can only be managed by open surgery.
The reality is that silos, economics, and practice patterns prevent this kind of combined effort. Market forces have pushed the training of vascular surgeons forcefully into the interventional realm at the cost of open surgical training. Some of the geographic maldisdribution of vascular surgeons has to do with younger vascular surgeons flocking to established practices where there are senior surgeons more comfortable in opening a belly or chest (or both). The trap they and hospital systems fall into is then allowing these new recruits to become the interventional specialist of that group, relegating the aging open surgeon to a narrow role, and then finding that the hospital has a problem when that surgeon announces retirement at 60. Every year, millennia of surgical experience retires to beaches and golf courses. The hospital systems should recognize this brain drain as a crisis and create work arounds that keep these skills going. The other opportunity lost is close coordination with interventional cardiologists, radiologists, and nephrologists who in many cases compete with vascular surgeons for the same patients but treat the patients based on their training and skill sets to the exclusion of potentially better operations offered by surgeons. This disjointed care creates both suboptimal outcomes for patients and high costs for hospital systems.
Commerce should never dictate the fate of a patient. A particular point is where competencies and privileging overlap, and guidelines recommend intervention over surgery as in the case of a TASC A or B iliac artery lesion. A patient should not be kept waiting weeks for a spot on a busy surgeon’s OR schedule when an open interventional cardiologist or radiologist slot is available for a iliac stent the next day. It should be a matter of practice that these cases are discussed and distributed, optimally in a shared indication clinic or rounds. Patients bumped off of a surgeon’s elective schedules for emergencies who could be cared for by an interventional partner without an added delay should be given that option. This kind of change requires a commitment to continual reorganization and optimization into a vascular institute.
The perfect vascular surgeon is a unicorn -well skilled, and experienced in open vascular surgery, but also versatile, innovative, and skillful in wielding a wire. I can name just a handful of unicorns. An apt analogy from the book Moneyball is the signing of superstars in baseball on the free agent market. The upshot of that book is that you can arbitrage for the valued metrics through signing several utility players with an aptitude for one thing or another which in sum equals or exceeds that superstar and get the final result -wins, in the same proportions as overspending on a superstar. Rather than searching for that unicorn, it is more important to set up the right system. Screening, testing, and management of mild vascular disease by a nurses and cardiovascular medicine physicians, while directing operations and interventions to vascular surgeons, cardiologists, and interventional radiologists should be the next step in the evolution of vascular care systems. There will never be enough vascular surgeons in the current system. The critical and rare competency is open vascular surgical skill. A surgeon who performs only interventions is not an “advanced minimally invasive practitioner” but rather someone equally privileged as an interventional cardiologist or radiologist, and therefore easily replaceable by an interventional cardiologist or radiologist specializing in peripheral vascular disease. A surgeon skilled in open vascular surgery is becoming rarer every year, but they are still out there, looking at brochures of real estate in sunny places. A team consisting of a cardiovascular medicine physician, many vascular technologists, nurses specializing in vascular diseases, several interventionalists, and a vascular surgeon skilled in open vascular surgery working as a single unit, is far more easy to assemble than finding and recruiting a herd of unicorns.