Something that I recently promised Dr. James S.T. Yao, I will be working to publish on my stent removal and extended remote endarterectomy cases and techniques. Meanwhile, here is a talk.
Hello Abu Dhabi
In Medicine, We Can All Be Real-World Innovators
Innovation has become a virtue in the current culture. There is an evangelical fervor around it. What are TED Talks but tent revivals for nerds? What is the new Apple campus but a cathedral born out of the values of our time? Yet in elevating the more famous innovators and inventions to lofty heights, we lose sight of its very practical and useful daily application. Rather than treat it like inspiration from the heavens, we should approach it as a trait that we all share in.
To make it work for you, you have to think of it as a muscle, and put your reps in. Here are a few “training” tips:
- If someone (maybe you) complains about something that feels like drudgery, fix it.
- Fix it like a life depended on it, because it just may.
- Accept that not everyone will get it.
- Do this every chance you get.
Many of us have stories about how we’ve taken opportunities to innovate. Here’s mine. When I was a second-year resident in the ICU back in 1994, we had a patient with HIV infection and necrotizing pancreatitis, requiring an open abdomen with three times a day sterile dressing change. These operations were performed in the ICU where the patient was left with an open abdomen with the pancreas which had exploded with inflammation was packed. The setup was quite hazardous because all the fluid splashing around was infected with HIV, occasionally bloody. But, it wasn’t just a hazard, it was a drudgery. Frustrated with the process, I came on the idea of inserting chest tubes over the packing and under the sticky adhesive drape, and then placing these on suction. I achieved a seal, and the ICU nursing staff was pleased with the invention. Thinking that I could escape the day without another hazardous dressing change, I took the time to pat myself on the back. Of course, I was called stat to the ICU and was dressed down by the head of the ICU for being both lazy and cavalier with the risk to the patient. Interestingly, though, a company came out several years later with a strikingly similar idea, and now negative pressure wound therapy is the standard of care in such situations. In fact, it’s a multi-billion dollar industry.
Of course, money shouldn’t be the sole motivation for innovation. I was motivated by doing less work, reducing the contamination threat for the ICU nurses, and improving care. Many of the best innovations in medicine help the physician care for the patient more efficiently, with better results, and with less suffering. Similarly, the Cleveland Clinic was conceived when American physicians and surgeons, while camped in the vasty fields of northern France during World War I, came to the realization that working collaboratively in a big tent across specialties and disciplines created great efficiencies and rewards, particularly in patient outcome. This innovation, encapsulated in the words “to act as a unit,” brought to the world the first multi-specialty clinics.
Here’s one last, more-recent example. I am frequently called emergently to an operating room to help control bleeding. Typically, these requests are from surgeons here at the Clinic working on severely scarred, radiated, or previously operated tissues. The typical routine is to dig out the vessel and clamp it, which is challenging because dissecting out the vessel can cause further injury to the vessel with more bleeding. I realized that a circular compressor would control bleeding and provide space for placing a repair suture (figure). When it works, it’s surprisingly easy. You can try it yourself; if you get bleeding from a vein on the skin, compress it with the ring handle of a clamp. This idea has gone to our Innovations office, is now patent pending, and is on track to be manufactured.
We became the dominant species on this planet through the trait of innovation. We could not migrate and survive on all the continents by waiting to grow fur, wings, or gills. Rather, we sallied forth, and we invented our way through deserts, mountains, ice fields, oceans, and jungles. Yet, inventiveness is not common, and it’s too often viewed poorly as a close cousin to cunning, or even sorcery. Innovation also threatens the status quo, because it brings change, and with that obsolescence. Innovation is risky, and the stakes are even higher in medical innovation. But, it’s also the only way we will solve what ails us.
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- Michael Park, MD is a vascular surgeon at the Cleveland Clinic and a 2017-2018 Doximity Fellow. He will be moving abroad to be chief of vascular surgery at Cleveland Clinic Abu Dhabi.
- Published Op-(m)ed on Medium link
Nutcracker Syndrome: The Renal Vein Transposition
Case Report
Patient is a 43 year old woman who had been having bouts of severe left sided abdominal pain for several years with worsening episodes of nausea and vomiting resulting in several visits to the emergency room. She has also had microscopic hematuria. Gastrointestinal workup including gastric emptying study, esophagogastroduodenoscopy and colonoscopy were negative, as was a workup for kidney stones. Eventually she was referred to my clinic for management of nutcracker syndrome. She denied lower abdominal pain nor excessive menstrual bleeding.
On examination, she was tender over the left kidney and flank. Laboratory examination was positive for microscopic hematuria. CT venography (below) showed an obstruction of her left renal vein by the superior mesenteric artery. Drainage via gonadal vein was not demonstrated, and no pelvic varices or complex of retroperitoneal veins was apparent.
Duplex showed the narrowing in the left renal vein and spectral Doppler showed elevated velocities across the compression caused by the superior mesenteric artery (below). The collecting system was not obstructed.
Treatment options included endovascularization with a large stent in the left renal vein, left renal vein transposition to a lower position on the inferior vena cava, left renal autotransplantation, and left nephrectomy. Stent placement comes with a degree of risk for cardiopulmonary embolism which may require a sternotomy to fish out an errant stent. The risk for this in the US is because the largest nitinol stents available are 14mm in diameter which might result in undersizing in a vein that could easily dilate to well over 20mm. Larger nitinol stents for venous applications are available in Europe but currently are not approved in the US (yet). Wall stents, while certainly wide enough, have the problem of being long and stiff when not fully deployed. A 22×35 Wall stent may be 50mm long if deployed inadvertently into a tributary vein or contrained at the narrowing. Because it slides easily, passing balloons in or out can cause it to slip out of position. Because this stent elongates when compressed and packed, deployment is challenging and it is prone to “watermelon seeding,” a set up for embolism. It does have the virtue of easy reconstraining.
My friend and recent host for Midwest Vascular Surgery Society Travelling Fellowship, Dr. John V. White, in Chicago, seems to have solved this problem by a multistep process of predeploying a temporary suprarenal IVC filter, deploying a stent (whatever fits), leaving the filter as a protection against stent migration for 4 weeks until the stent permanently seats itself through scarring/intimal ingrowth, then removing the filter.
I chose to perform venography and renal vein transposition. The patient was placed in a supine position on a hybrid angiographic operating room table and her right femoral vein was accessed. She was placed in 15 degrees reverse Trendelenberg which is about the upper limit possible. Venography below.
After heparinizing and clamping, the renal tributary was taken with a 5mm cuff –this would ensure proper length without narrowing the IVC.
The vein was anastomosed and flow was excellent by pulse Doppler.
She recovered well but had a longer stay because of an ileus, being discharged on day 5. Because she lived at a distance, and came back for followup the following week prior to boarding a plane for home. She no longer had the left sided abdominal pain and there was no hematuria. CT showed excellent drainage through the transposed vein.
Followup will be periodic (6 monthly) renal venous duplex from home. Given that there was minimal tension on the repair, I expect this to do well.
Discussion:
Nutcracker syndrome is one of the many unfortunate consequences of our bipedal lifestyle. The small intestines hang like baggy sausages off the branched stems of the superior mesenteric artery (SMA), and in some individuals, the SMA compresses the left renal vein against the aorta. The left renal vein receives up to 12-15% of cardiac output via the left kidney, and with outflow obstruction, drains the blood through small collaterals. The renal venous hypertension results in swelling of the left kidney with subsequent left renal colic -with flank and abdominal pain, nausea, and vomiting. There is hematuria which can be gross or microscopic. With drainage via an incompetent gonadal vein, varicoceles can occur with discomfort in men and pelvic varices with pelvic congestion syndrome can occur in women.
Diagnosis is challenging because it is one of the relatively rare non-gastrointestinal causes of abdominal pain (table).
- Mesenteric ischemia
- Median arcuate ligament syndrome
- Nutcracker syndrome
- Neuromuscular
- Urolithiasis
- Inflammatory aortitis/arteritis
- Hypersplenism
- Portal hypertension
- Arterial aneurysm
- Infections
- Pelvic Congestion Syndrome
- Endometriosis
- Hernias
A history of left sided abdominal pain, flank pain, nausea, vomiting, associated pelvic pain, and episodes of hematuria are diagnostic. Examination is typically positive for left renal tenderness and flank tenderness. Laboratory examination include urinalysis for hematuria. Duplex, while technically challenging, will show renal venous compression with velocity elevation or loss of respirophasicity, CTA will typically show obstruction of the left renal vein with filling of collaterals, as will MRV.
Venography should be done in a stepwise manner (White protocol) to fully demonstrate the maldistribution of blood. That is the key word, maldistribution. I learned from my fellowship with Dr. White that performing venography in as upright a position as possible recreated the pathophysiology, the physics, particularly for pelvic congestion and nutcracker. Remember, this is a disease of bipedalism, of upright posture. Many negative studies done supine become positive, as the contrast will fall to where it prefers to go. As I have stated in the past, on the venous side, demonstrating drainage has different imaging needs than demonstrating flow. Pathologic venous drainage has three characteristics:
- Varicose veins develop as an end stage process
- Reversal of flow or reflux is demonstrated, particularly into small tributary veins
- The midline is crossed in these usually small, now larger, collateral veins
While pressure gradients are nice if they are large, they are difficult to assess when they narrow to 1-2mmHg, particularly if they vary with cardiac cycle and respiration. Because we are assessing drainage, the distribution of contrast and the direction it goes is particularly important, and far more sensitive than pressure measurements.
Venography was done per a modification of Dr. White’s protocol for pelvic congestion:
- Steep reverse Trendelenberg
- Hand injection 10mL half diluted contrast, gently as to not create false reflux
- Runs with catheter in left EIV, right EIV, left renal vein, right renal vein
- With pelvic congestion workup, add selective bilateral gonadal and internal iliac veins.
I have started transposing gonadal veins when they have enlarged from chronic reflux (link, ref 2). Renal vein transposition was chosen because her ovarian vein was competent and too small to transpose (ref 1-3). While the patency rate of stents in veins seems to be acceptable, long term data is unavailable. Also, venographic appearances are deceiving -see the in-vivo measurement of the left renal vein after dissection:
References:
- White, J. et al, Left ovarian to left external iliac vein transposition for the treatment of nutcracker syndrome. J Vasc Surg Venous Lymphat Disord. 2016;4:114–118.
- Miler R, Shang E, Park W. Gonadal Vein Transposition for the Treatment of Nutcracker Syndrome. Annals of Vascular Surgery 2017, July 6. in press. http://dx.doi.org/10.1016/j.avsg.2017.06.153
- Markovic J, Shortell C. Right gonadal vein transposition for the treatment of anterior nutcracker syndrome in a patient with left-sided inferior vena cava. J Vasc Surg Venous Lymphat Disord.2016 Jul;4(3):340-2. doi: 10.1016/j.jvsv.2015.09.002.
- Erben Y, Gloviczki P, Kalra M, Bjarnason H, Reed NR, Duncan AA, Oderich GS, Bower TC. Treatment of nutcracker syndrome with open and endovascular interventions. J Vasc Surg Venous Lymphat Disord. 2015 Oct;3(4):389-96. doi: 10.1016/j.jvsv.2015.04.003.
Case report up on Annals of Vascular Surgery -Gonadal Vein Transposition for Nutcracker Syndrome
A case report co-authored by my recently graduated trainees, Drs. Roy Miler and Eric Shang. An update to be presented at Midwest Vascular Surgery Society Meeting in Chicago.
When Hybrid Seems Better: Carotid Trauma As a Model For All Trauma
History
The patient is an 80 year old woman with lung cancer who was getting a port placed at her home institution. It was to be a left subclavian venous port, but when access was not gained, a left internal jugular venous port was attempted, but after the intitial stick and sheath placement, pulsatile bleeding was recognized and the sheath removed. Hemostasis was achieved with clips and the wound closed and a right internal jugular venous port was placed. The postprocedural CXR shown above showed tracheal deviation and numerous clips from the initial port placement attempt, and a CT scan with contrast (unavailable) showed a carotid pseudoaneurysm of 3cm projecting posteriorly behind the pharynx/esophagus. She was kept intubated and sedated, and transferred for management.
On examination, her vital signs were stable. She had 2cm of tracheal deviation and swelling was apparent at the base of the neck. While my trainees may be better versed at this than I at the particulars of this, my old general surgery trauma training kicked in, as she had a Zone I neck carotid injury, 
which in my experience is highly morbid despite how stable the patient was. Point again to trainees, this is no different from someone having stabbed this patient with a knife at the base of the neck. My options were:
- Open repair
- Endovascular repair from femoral access
- Hybrid repair
Open Repair
Open repair is the approach of choice for zone 2 injuries because aerodigestive tract injuries can also be addressed and the exposure is straightforward. For Zone 1 injury, the exposure is potentially possible from a neck exposure, but in my experience, jumping into these without prepping for a sternotomy puts you into a situation without a plan B. The exposure of the carotid artery at this level becomes challenging with hemorrage from the artery once the compression from the hematoma or pseudoaneurysm is released. A sternotomy in this elderly woman, while not optimal, may be necessary if open control is required, but the best plan is to avoid this.
Endovascular Options
This should be a straightforward repair from an endovascular approach, even with the larger sheath required for the covered stents. A purely endovascular approach is problematic for two reasons. One, cerebral protection devices are built for bare carotid stents and not peripheral stent grafts, but this is not prohibitive -it should be fine. Without a planned drainage, the hematoma would be left behind which could cause prolonged intubation and problems with swallowing -both an issue for an elderly patient battling lung cancer. Endovascular access could provide proximal control for an open attempt from above, but instrumenting from the arch in an 80 year old has a known 0.5-1% stroke rate.
Hybrid Repair
A hybrid open approach with exposure at the carotid bifurcation offers several advantages. With control of the internal carotid artery, cerebral protection is assured while the carotid artery is manipulated. At the end of the procedure, the internal carotid can be backbled through the access site with the common carotid artery clamped. The hematoma could be avoided until the stent graft is deployed. An unprotected maniplation in the arch can be avoided. Once the stent graft is deployed, drainage of the hematoma can be performed.
This required setting up a table off the patient’s left that allowed the wire to lie flat to be manipulated by my right hand. The carotid bifurcation was accessed through a small oblique skin line incision and the common, internal, and external carotid arteries, which were relatively atherosclerosis free, were controlled with vessel loops. The patient was heparinized. The internal carotid was occluded with the loop, and the common carotid below the bifurcation was accessed and an 8F sheath with a marker tip inserted over wire. Arteriography showed the injury and pseudoaneurysm.
The location of the injury based on CT and on this angio would have baited a younger me into directly exposing it, but experience has taught me that which occasionally you can get away with it, the downsides -massive hemorrhage, stroke, need for sternotomy, just aren’t worth it. The sheath was brought across the injury and a Viabahn stent graft was deployed across the injury.
The hemorrhage was controlled and the hematoma was then exposed and drained -the cavity was relatively small and accepted the tip of a Yankauer suction easily. A Jackson-Pratt drain was placed. The access site was repaired after flushing and retrograde venting as described.
She recovered rapidly after extubation postop. She was able to breath and swallow without difficulty and had suffered neither stroke nor cranial nerve injury. The drain was removed on postop day 2.
The patient recently returned for a 6 month followup. Duplex showed wide patency of her stent.
More gratifyingly, her port was removed as her cancer was controlled with an oral regimen.
Discussion
Let me start with my bias that all penetrating trauma should be approached in a hybrid endovascular OR. It is a natural setting for trauma and this case illustrates that. In a hybrid operating room, central aortic and venous injuries can be controlled endovascularly while open repair, including salvage packing, can be done. Excess morbidity of central vascular exposures can be avoided. Temporary IVC filters can be placed if indicated (becoming rarer and rarer). Cardiopulmonary bypass can be started.
In this patient, hybrid therapy brought the best of both techniques and avoided many of the pitfalls of the purely open or endovascular approach. For stable zone I penetrating injuries of the neck, it is clear that this is a reasonable approach.
May-Thurner Syndrome Causing Pelvic Congestion -Pathoanatomy Movie
