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

preop CTA EVAR-ENDORE.jpg
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.

Preop left and right centerlines EVAR-ENDORE.jpg

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

AUI fem fem.jpg
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

postop centerline EVAR-ENDORE
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

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

ct-3dvr-planning

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.

ct-3dvr-planning

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).

or-view_1

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.

postop-duplex

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.

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. 

3DVR -Very Helpful in Planning Open Surgical Cases

3DVR CIA Endart

The images above show a patient with on isolated occlusion of his left common iliac artery. He was young, in his forties, but was a heavy smoker and suddenly developed claudication of his left leg which interfered with his work. He quit smoking and did not progress with exercise. Discussion involving possible stenting was made and initially offered but he turned it down because erroneously he assumed that his father’s coronary stents were the same as an iliac stent in terms of longevity. I do think that common iliac and aortoiliac occlusive disease is well treated with stents, but I felt it was possible to do a common iliac endarterectomy. We went over these images together and he settled on proceeding with endarterectomy.

The images show how well the 3D Volume Rendering, which I mentally call Virtual Reality, of CTA makes it possible to plan out operations and exposures virtually. The bottom left image shows the surgeon’s eye view of the exposed vessel.

Below, the virtual and the actual are juxtaposed.

3DVR CIA Endart Exposure

The outline on the virtual image (volume rendered) shows the areas of retraction -for the trainees, the retractor systems work to make quadrilaterals out of linear incisions, and as a rule, the incision should be twice the length of the square that you want to expose. The end points of the endarterectomy were at the aortic and iliac bifurcations.

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The arteriotomy was repaired with a patch at the iliac bifurcation -the common iliac was large and was repaired primarily.

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The specimen below was fibrocalcific. The thing about this disease is that the plaque truly has no endpoint -intimal thickening and mild plaque was present that could be taken all the way to the aortic root and to the feet on the other end!

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This patient did very well and had palpable pulses. He did not develop neointimal hyperplasia and successfully quit smoking.

One of the exciting developments is the ongoing development of wearable virtual reality and display solutions -particularly from the gaming industry. The gaming industry ironically drives all computer imaging because that is where the money is at. The advances in imaging trickle down to medicine -the VR images seen here are the result of the same algorithms that drive first person shooting games. It would be great to see this displayed intraop on a HoloLens, on a virtually positioned screen behind the assistant!

Mind the Lymphatics: managing a persistent postoperative seroma

figure 1

The patient was referred from an outside institution for the development of a large tender mass in her below knee incision after a femoropopliteal bypass done with PTFE for ischemia after a aorto-bifemoral bypass. The patient reported swelling that grew in the months after the operation to the point that she was unable to walk without pain. On examination, she had a Nerf football sized swelling in her previous below knee incision without erythema. It was quite tender. CTA showed a patent aorto-bifemoral bypass and a femoropopliteal bypass to the below knee popliteal artery. Incidentally noted was the absence or occlusion of the profunda femoral artery. There was bland lymphedema below the knee.

Differential diagnosis included:

  1. Graft Infection
  2. Seroma from PTFE ultrafiltration leak
  3. Seroma from lymph leak.

Graft infections can present like this, but also drive local and systemic inflammation and in the absence of fevers and white counts, was highly unlikely. Occasionally, indolent infections with S. epidermidis will present with fluid collections but typically this is a late presentation. Ultrafiltration leaks from PTFE are fairly rare in my practice but can occur randomly. Most PTFE grafts nowadays come with an external wrap that acts as a seal against microporosity, but on occasion, I have seen protein rich fluid accumulated around PTFE grafts. This typically is not high pressure and accumulates along significant or whole length of graft. I used to treat that with graft excision and replacement, but I have had success with relining the graft with PTFE based stent grafts and externally draining the seroma.

I suspected this to be a seroma from lymphatic leak. The lymphatics are an unusual system of vessels in that they are remnants of an earlier circulatory system that was designed to move and mix nutrients and primitive phagocytic immune cells throughout the external compartment of an organism. They are diaphanous vessels that have smooth muscles that periodically contract like cardiac muscle, propelling fluid and cellular components past valves. Typically, cautery, suturing, and the inflammation of wound healing are sufficient to close lymphatics, but when there is potential space and a large lymphatic trunk that has been divided within it, that space will be filled with fluid, particularly with edema fluid that accumulates post surgically with dependency.

This patient was treated with I&D, but the lymphatic was identified by injection with Isosulfan blue in the subcutaneous space of the foot (between the toes). The dye is avidly taken up by the lymphatics and it can be used to identify the leak, allowing for extirpation and closure.

Isosulfan blue is injected into the subcutaneous spaces between the toes.
Isosulfan blue is injected into the subcutaneous spaces between the toes.

The vital dye will be cleared by the kidney -the pee will be greenish blue for a day or two. This is contraindicated in patients with known sulfa allergies.

The dye is seen in the wound within minutes without any added measures -no pumping or massaging was required. The patient had begun spontaneously draining the night before her operation.
The dye is seen in the wound within minutes without any added measures -no pumping or massaging was required. The patient had begun spontaneously draining the night before her operation.

The dye concentrates in the lymphatics which are easily identified.

IMG_5298

The lymphatics were ablated and a VAC dressing was applied. Two weeks later, there has been significant healing with complete resolution of the seroma.

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Loss of lymphatics at this level does not cause permanent injury but clearance of edema is slowed. Clearly, the avoidance of lymph leaks is the first step in preventing seromata, but when they occur, it is simple enough to identify and treat them using this technique.

They are one way self circulating pipes and therefore treating the afferent termini is all that is necessary.
They are one way self circulating pipes and therefore treating the afferent termini is all that is necessary.

The right and left carotid bifurcations usually look like this

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Maybe it’s the way the the bilateral dorsal aortas resolve into an asymmetric arch, but there is asymmetry in the carotid arteries which lets me look at a lateral carotid arteriogram and reliably predict which carotid artery it is. Image I is the usual conformation of the right ICA takeoff which may be tucked ,medially and posteriorly toward the pharynx. Image II is the typical forked appearance of the left ICA, and because it is longer and the plaque usually ends at the bend, this makes an eversion easier on that side. I began noticing this when I was on the CVRx trial applying stimulator leads on the carotids.

Suprising result from gunshot wound to chest

 

bullet CTA

 

The patient was shot in the right shoulder and had walked to the emergency room with some dyspnea and back pain. CXR showed a right sided pneumothorax but no bullet. The paper clip on the 3D VR view of the CTA shown above is the entry wound. The green line traces the centerline of the aorta, aortic arch, and the right carotid system. The patient’s assailant was shooting from a balcony of a movie theater. Vascular surgery was consulted for loss of pulse in left leg during trauma workup.

CT scan of the chest and abdomen showed blood in the mediastinum and haze around the distal thoracic aorta.

Remarkably the patient remained stable. My plan was to cover the aortic perforation with a stent graft, but an appropriately sized graft for patient’s size was not available at that time in 2009, so we used a Zenith RENU cuff. The patient on examination had an absent left femoral pulse. I chose to explore this and use it as the access site of the TEVAR. I also made sure the detectives put on scrubs to receive the bullet as US laws about evidence requires witnessed removal and acceptance of criminal evidence.

The cutdown revealed the bullet (9mm round) to be lodged in the common femoral artery. It was placed in a kidney basin with a loud clank and handed off to the peace officer for processing.

The bullet managed to miss the esophagus, heart, major pulmonary vessels, upper abdominal organs, and gently nestled in the aorta and embolized to the femoral artery in the emergency room.

The RENU cuff’s delivery system was long enough –at the time of this procedure, smaller diameter thoracic stent grafts were not available and in the setting of trauma with younger patients, particularly female patients, this was a problem. An aortic cutdown was sometimes necessary to deliver a 24mm aortic cuff up near a tear due to deceleration at the ligamentum arteriosum of the pulmonary artery and aorta. The patient recovered well and this case report was written up by Dr. Jared Kray who is now a vascular surgery fellow in Missouri –the article is in print for the January issue of American Surgeon.