SVC Syndrome: Right Internal Jugular Vein Pressure is Intracranial Venous Pressure

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The patient is a young father in his early thirties who complains of severe headaches, dyspnea, and inability to function or interact with his toddler. He complains of visual disturbancers when bending over and has dilated neck veins when recumbent. He was born with aortic stenosis and has undergone three aortic valve replacements and has had pacemakers since childhood. His most current pacemaker is a DDDR pacemaker in his left subclavian venous position, but he has two dead leads in his right subclavian vein. His symptoms started in his twenties but has worsened sharply over the past year. An effort was made to remove his dead leads at a tertiary referral center, but they couldn’t.

On examination, he had significant findings from dilated neck and supraclavicular fossa veins, a left chest pacemaker, and scars from his sternotomies. Duplex showed a patent bilateral internal jugular veins (IJV) with minimal respirophasic variability.

Venography (composite, above) showed superior vena cava occlusion consistent with his diagnosis of SVC Syndrome. I measured venous pressures, which we normally don’t do, because I was curious about them. Right IJ access with ultrasound with a sheath revealed pressures on the monitor in CVP mode of 22mmHg. Access from the groin into the heart revealed a right atrial (RA) pressure of 14mmHg. The SVC was crossed from below into the right IJV, and the SVC was dilated with a balloon -no stenting was possible because of the presence of the leads. His pacemaker did not fail during the procedure. After balloon dilatation, contrast passed easily from his IJV into his RA (below). His pressure in the R. IJV was 17mmHg and in the RA was 16mmHg.

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He immediately felt relief and in 1 month followup had sustained symptom relief with patent flows seen in right IJV. He understood it was likely he would need regular reintervention when symptoms returned.

Discussion:

While IVUS is usually the way to check on patency after venous intervention, the presence of permanent pacemaker leads, including a set of nonfunctioning leads from the right SCV, made its use moot -venoplasty to 12mm was done in multiple stations and there was to be no stenting which is the usual next step if IVUS found residual stenosis. The more interesting finding here is the pressures measured in the IJV. The symptoms of SVC syndrome come from venous hypertension, but we rarely if ever measure pressure. Intracranial pressure (ICP) which is used to monitor for critical hypertension in the cranium typically after surgery or trauma, is considered high if over 15mmHg, moderately elevated over 20mmHg, and severe when over 40mmHg. ICP is greater than or equal to intracranial venous pressure, and in patients with SVC occlusion, this pressure is equal to the IJV pressure. With an IJV pressure of 22, this patient’s ICP was likely over 20mmHg, explaining his incapacitation.

IJV pressure is easily obtained and may justify urgent intervention in acute SVC syndrome, although more data needs to be obtained. This patient will benefit most from a more durable solution, but for now, he is very pleased to be able to take part in the care of his young child.

POTS+May-Thurner’s Syndrome: Rare Disease Causes Rare Disease?

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The patient is a younger man in his twenties who began having dizzy spells associated with near syncope and tunnel vision. He was previously an athlete and was fit and never had such episodes -he had a resting heart rate typically in the 60’s or lower. Workup for arrhythmias was ultimately positive for POTS -postural orthostatic tachycardia syndrome and he was referred to Dr. Fredrick Jaeger of our Syncope Clinic. Tilt table testing the demonstrated the reported tachycardia over 140bpm while upright rising from 60bpm while supine. A radionuclide hemodynamic study (Syncope Radionuclide Hemodynamic Test) showed 54% of his blood volume pooled in his left lower extremity and lower abdomen with upright posture. Air plethysmography (PHLEBOTEST) showed abnormal refill and fill times in both legs and a duplex of the legs showed deep venous reflux in both legs. MRV revealed narrowing of left common iliac vein by the overlying right common iliac artery (May-Thurner’s Syndrome, MTS), and this was where the patient came to my clinic.

The MRV, shown above and below showed the typical pathoanatomy for MTS, but the patient had no symptoms related to left leg swelling, DVT, or varicosities. He did have a reducible left inguinal hernia which was quite tender.

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After some deliberation, while not promising anything regarding his POTS, I agreed to proceed with treating his pathoanatomy. Discussion with Dr. Jaeger revealed this: normally about 20% of blood volume parks in the legs with standing which is rapidly dissipated with normal calf muscle pump action. In a subset of patients with POTS, there is a 30-40% maldistribution of blood volume into the legs which may or may not drive the autonomic responses leading to POTS. He has never seen a study result showing a 54% distribution.

It made physiologic and anatomic sense to me to proceed with a venogram and intervention, but I confess I was dubious about any affects I might have on the patient’s POTS and I informed him of it. Also, I recommended seeing a general surgeon for his hernia.

Venography showed obstruction of his left common iliac vein as evidenced by the filling of pelvic and lumbar collateral veins.

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Intravascular ultrasound showed the narrowing better and more directly (panel below). The right common iliac artery narrowed the left common iliac vein severely.

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A 22mm Wall Stent was positioned across this and dilated with a 22mm balloon in the IVC and an 18mm balloon in the iliac vein. The resulting venogram showed resolution of the obstruction with collateral veins no longer visualized (below).

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But again, IVUS demonstrated more directly the result (and illustrates the importance of having IVUS available for venous interventions).

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The patient was discharged after procedure on a baby aspirin only. He subsequently underwent laparoscopic inguinal herniorrhaphy and returned to my clinic about a month later. His followup duplex showed a widely patent stent and normal flows in the left iliac venous system.

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Surprisingly -the patient declared that he was cured of his POTS. He said since the stents went in, he has not had any more episodes of near syncope, dizziness, tunnel vision, nor weakness requiring lying down to rest. His wife confirmed that he was a flurry of activity over the holidays that was surprising considering how debilitated he was before. This is astonishing to me.

But it should not be a surprise given this: if the POTS symptoms were the result of autonomic dysregulation, a breakdown of the feedback control loop, there were only several places this could be a problem.

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The pathology, the MTS, explains the POTS in this instance very nicely. Because the problem was in the cardiovascular system part of the diagram which I can fix and not the autonomic nervous system control element, which I can’t fix yet, a solution could be tried. This was not an asymptomatic compression of the iliac vein which we do encounter as an incidental finding. It seems to be POTS caused by MTS, and cured for now by treatment of the MTS.

 

 

The Geometry of Parallel Grafts in the Iliac Arteries

The development of metachronous common iliac artery aneurysm, or progression of them, after prior treatment with EVAR (endovascular aneurysm repair), particularly with “bell bottoming” is typically treated with coil embolization of the internal iliac artery and extension of the stent graft into the external iliac artery. While CH-EVAR has been in the news with the recent results from the PERICLES registry, I have never been entirely convinced of its durability. That is different in the case of building parallel grafts in an iliac limb of an EVAR graft (reference).

Here, the geometries, thrombosis, and forces combine to make gutter flow and endoleak unlikely. Choosing the right size of stent grafts to channel to the external and internal iliacs seems to be a challenge, but is easily solved by this scheme -which I can’t claim as my own, but was thought up by a surgeon in upstate New York who choses to remain anonymous.*

The diameter of the stent graft to be sealed to is measured and an area calculated. The sum of the areas of the two grafts to be placed need to equal or slightly exceed the area of this inflow stent graft. If you have decided the size of the external iliac graft, for example, then the diameter of other graft is merely a few geometric formulas away.

Here is a table that can be helpful in avoiding those formulas.
diameter area table.jpegThe inflow graft area is taken from its measured diameter. Then usually one or the other artery has an obligate size -a size the graft has to be while the other has more “wiggle room.” The other thing that comes from experience is that the AFX graft’s iliac limb extension don’t get the B-infolding that can affect an oversized stent graft placed in a small artery and it accomodates a neighbor well.measurement_3

For example, take this patient who after EVAR of aortic aneurysm with AFX developed metachronous dilatation of the common iliac artery to 3.9cm with abdominal pain. The average diameter is 18.5mm. From the table, that rounds to 19mm corresponding to 283.53 square mm. If the internal iliac artery requires a 13mm graft, that is 132.73 square mm, the difference being 150.80 square mm. That corresponds to a 14mm diameter graft, but a slightly larger graft is preferred for oversizing. The external iliac artery is 8mm, and putting a 13mm Viabahn (largest available) in that would result in the B-infolding in the 8mm external iliac. Here, I bailed myself out by simply placing a 20mm AFX iliac limb extension, which by virtue of its design is resistent to infolding and tolerant of parallel grafts laid alongside in constricted channels. I found that the AFX iliac limb, a 20-13mm x 88mm length extension well suited for this.

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The AFX graft limb seems to adapt to the presence of the parallel “sandwich” graft which is deployed second and ballooned last. In followup, there was shrinkage of the common iliac artery aneurysm sac and no endoleak.

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Compared to my other parallel graft case treating a metachronous saccular common iliac aneurysm years after an EVAR with a Gore endograft (link), which by table calculation, resulted in 8% oversize in calculated areas, this particular technique with a large AFX graft and an appropriately sized Viabahn seemed to work well the setting of a previously placed AFX graft. It allows one to avoid hypogastric occlusion.

The final option of a femoral or external iliac to internal iliac bypass after extension across the bifurcation to the external iliac artery is still a reasonable choice, although it seems to be receding into history.

Reference

Smith, Mitchell T. et al. “Preservation of Internal Iliac Arterial Flow during Endovascular Aortic Aneurysm Repair Using the ‘Sandwich’ Technique.” Seminars in Interventional Radiology 30.1 (2013): 82–86. PMC. Web. 9 Dec. 2016.

*While these grafts are not FDA approved for use in this manner, many times, with a prior endograft or graft in place, using the currently available and approved Gore Iliac Branch Endoprosthesis (IBE) in this common scenario would still be off label usage of an approved device, and only if it is feasible, which most times is not. For nonmedical readers, many commonly available devices and medications are used off-label, such as aspirin for blood thinning.

Bypasses still work -a guest post from Dr. Max Wohlauer

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Max Wohlauer, a recent graduate, is now Assistant Professor of Surgery at the Medical College of Wisconsin in the Division of Vascular Surgery. He sent along a case which is published with his patient’s and department’s permission.

The patient is an 80 year old man with diabetes mellitus, CHF, and pulmonary fibrosis, who presents with right foot toe ulcers. He had an inflow procedure earlier in the year, but it failed to heal the ulcers. An attempt at crossing a CTO of the SFA/POP failed. Angiogram (above), showed a distal anterior tibial artery target.

Preop ABI, TBI’s, toe waveforms, and pulse Dopplers are shown. are as shown.

 

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All point to likely limb loss. The TBI is 0 and the ABI is incompressible. Max planned for bypass. The saphenous vein was mapped and shown to be adequate.

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Max comments:

  • Compromised runoff on angio. Cutdown on AT and determined it was adequate target at start of case
  • Right fem-AT bypass
  • Re-do groin exposure
  • Translocated non-reversed GSV
  • Subcutaneous tunnel

 

The operation went well. Completion angiography was performed showing a patent bypass and distal anastomosis with good runoff.

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A followup duplex showed patency of the graft.

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Postop ABI’s showed excellent results:

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Commentary from Park

Bypasses work and are possible even in high risk individuals with good anesthesia and postoperative care. Because open vascular surgical skills are not well distributed while endovascular skills are more widely distributed, there is bias both in the popular mind and even among some catheter based specialists that bypass surgery is a terrible, no good thing. The fact is that a well planned bypass is usually both effective and durable even in high risk patients, but clearly it is not the only option.

Ongoing developments in endovascular technology bring greater possibilities for revasularizing patients. As someone who does both interventions and operations, I have seen spectacular success (and occasional failure) with both approaches, and I admit to having biases. It is human nature to be biased, but it is because of my biases, I support further ongoing study, as the mistake would be to establish monumental truths without supporting evidence. There is an ongoing randomized prospective trial (BEST-CLI) that aims to answer important questions about what approach brings about the best results in critical limb ischemia. It will bring evidence and hopefully, clarity, to this important disease.*

Finally, I am very proud to have participated in Dr. Wohlauer’s training, and look forward to seeing his evidence, experience, and even biases, presented at future meetings.

 

*CCF is a BEST-CLI study site.

Takayasu’s Arteritis Driven Median Arcuate Ligament Syndrome: Unusual Symptoms Demand Unusual Solutions

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The patient is a young woman from overseas who was referred to the clinic for abdominal and chest pain that persisted after diagnosis and treatment of Takayasu’s Arteritis affecting her visceral (middle) aorta. A year prior to presentation, she had been having severe abdominal pain, 30 pound weight loss, and weakness. Laboratory findings included elevated inflammatory markers. CT scan showed inflammation around her celiac axis and superior mesenteric artery. She was treated with prednisone but only responded ultimately to immunosuppressives. Her pain remitted for a while and she regained weight and strength, but eventually in the months prior to consultation, symptoms of postprandial abdominal pain and nausea set in with concomitant constant midsternal chest pain which at times was incapacitating.

Examination was remarkable for a well nourished young woman in distress with epigastric tenderness. Inflammatory markers were normal and she was on methotrexate and tocilizumab. CTA (above) and duplex showed severe stenoses affecting the origins of the celiac axis and superior mesenteric artery. A composite of the centerlines through these showed the arteries to be critically narrowed at their origins (below), along with a mild to moderate stenosis of the aorta (above). No active inflammation could be seen.

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The anterior view of the 3DVR images of her CT showed an absence of collateralization via the inferior mesenteric artery and Arc of Riolan.

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This could account for her postprandial abdominal pain which was midabdominal, but the midsternal chest pain was difficult to explain. A cardiac cause had been ruled out at her home institution. It was on the lower part of the sternum and bordered the epigastrium. Through my work with median arcuate ligament syndrome, it was not unusual to have chest pain be part of the pain syndrome which comes about through the compression of the celiac plexus by the median arcuate ligament (reference), and treated effectively with the division of the median arcuate ligament and celiac plexus neurolysis.

I did feel that revascularizing the SMA was likely to improve her postprandial symptoms, given the paucity of circulation to the gut. I had a discussion about her chest pain and the thought that this was a celiac plexus neuropathy as the result of compression of the celiac plexus by her Takayasu’s disease. Typically, for younger people, I perform a bifurcated graft to the celiac axis and SMA from the distal descending thoracic aorta for younger patients, but I had no intention of replacing her aorta at this time, and wanted to reserve any definitive revascularization of her visceral vessels for a later time if it became necessary. Her pulses were full in the legs and she had no hypertension, renal insufficiency, or claudication. I therefore planned a ilio-mesenteric bypass, as it would preserve planes for a later more definitive operation if necessary, and would address her mesenteric ischemia.

I also proposed taking down the median arcuate ligament and lysing her celiac plexus to treat her chest pain symptoms. While I knew this would be fraught with some hazard because of the inflammation that had been there, it would be the best chance at treating this symptom that was debilitating her. I did not think the constant chest/epigastric pain had a vascular etiology. Normally, I would test this with a celiac plexus block, but given the likely inflammation involved, a failed block would not be helpful, and a positive one achieved with some difficulty.

The patient thought this was reasonable and agreed. She underwent a midline laparotomy and I exposed both the SMA and right common iliac artery in the retroperitoneum and tunneled a PTFE graft in a C-pattern in the retroperitoneum. The SMA was diseased proximally under the pancreas and affected by inflammatory scar tissue, and the vessel was thickened as well. The iliac pulse was normal and full and provided excellent inflow.

Going into the lesser sac, the crurae of the diaphragm were heavily scarred near the celiac axis. Division of these fiber was taken slowly and with the aid of both loupe magnification and a hook cautery (borrowed from laparoscopic surgery). The aorta was cleared of tissue first -it was also encased in scar tissue. The dissection going distally was made difficult by inflammatory scar tissue as well, but several large nerve trunks were encountered and divided. The celiac axis was atretic and small within this scar tissue, but was released down to the trifurcation.

The recovery was notable for remission of her chest pain and her ability to resume eating without pain or nausea. A CTA done before discharge showed a patent bypass.

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Followup communication has revealed continued remission of her presenting symptoms months after her operation.

We are working on presenting a followup to our recent paper on MALS. Increasingly, it is apparent that consideration of celiac plexus compression as an etiology of epigastric abdominal pain unexplained by more common gastrointestinal causes provides solutions for patients given no explanation for their debilitating pain. This pain can also affect the chest, and flanks and back in the distal thoracic dermatomes, and mimic the some of the symptoms of mesenteric ischemia. In those with recurrent MALS after a successful ligament release and interval of symptom remission, even in the absence of celiac axis compression, a positive response to a celiac plexus block points to the presence of either remnant plexus fibers or compression by scar tissue of the cut nerve endings (neuromata) and reoperation has been successful. Extrapolating this experience to this patient with inflammatory compression of the celiac plexus secondary to Takayasu’s Arteritis made sense and celiac neurolysis appears effective.

Reference

Weber JM, Boules M, Fong K, Abraham B, Bena J, El-Hayek K, Kroh M, Park WM. Median arcuate ligament syndrome is not a vascular disease. Ann Vasc Surg. 2016 Jan;30:22-7.

External iliac remote endarterectomy restores the artery to normal, opening the way for EVAR, TAVR, TEVAR, and transplant: alternate applications of EndoRE

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One of the nice things  about practicing at the Clinic is being able to offer unique solutions. A severely diseased or occluded external iliac artery (EIA) can be a vexing problem, particularly if bilateral, in this endovascular era. Many cardiovascular devices require femoral access that has to traverse compromised iliac arteries -those with large (>16F) delivery systems require a sufficiently wide path to get the devices to the heart and aorta. Also, living related donor kidney transplantation is predicated on minimizing risk to maximize results and having significant iliac plaque negates one as a recipient for this high stakes elective procedure. In situations where the EIA is too small to accommodate devices because of atherosclerotic plaque, the typical solution is placement of a conduit to the common iliac artery or the aorta. The practice of “endopaving” with a covered stent graft and ballooning is also described, but its long term outcomes are not reported and the internal iliac artery is usually sacrificed in this maneuver.

This patient presents with lifestyle limiting claudication and an absent right femoral pulse. ABI is moderately reduced on the right to 0.57, and he had no rest pain. CTA at our clinic revealed an occluded EIA bracketed by severely calcified and nearly occlusive plaque of the common iliac artery (CIA) and common femoral artery (CFA).

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Centerline Projection

The patient was amenable to operation. Traditionally, this would have been treated with some form of bypass -aortofemoral or femorofemoral with a common femoral endarterectomy. While endovascular therapy of the occluded segment is available, one should not expect the patencies to be any better than that of occlusive lesions (CTO’s) in other arteries. Hybrid open/endovascular therapy is an option as well with CFA endarterecotmy and crossing CIA to EIA stents, but I have a better solution.

The common femoral endarterectomy rarely ends at the inguinal ligament, and is uniquely suitable for remote endarterectomy, a procedure from the early to mid twentieth century.

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Steps in Remote Endarterectomy

 

The addition of modern fluoroscopic imaging and combining with endovascular techniques makes this a safe and durable operation.

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The patient was operated on in a hybrid endovascular OR suite. A right groin incision was made to expose the common femoral artery for endarterectomy and left common femoral access was achieved for angiographic access, but also to place a wire across the occlusion into the common femoral artery.

All actions on the external iliac artery plaque are done with an up-and-over wire, allowing for swift action in the instance that arterial perforation or rupture occur. This event is exceedingly rare when the operation is well planned. With this kind of access, an occlusive balloon or repairing stent graft can be rapidly delivered.

The common femoral endarterectomy is done from its distal most point and the Vollmer ring is used to mobilize the plaque. A Moll Ring Cutter (LeMaitre Vascular) is then used to cut the plaque.

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The plaque is extracted and re-establishes patency of the EIA.

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Plaque Specimen

The plaque end point is typically treated with a stent -in this  case, the common iliac plaque was also treated.

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What is nice about this approach is that this artery has been restored to nearly its original condition. I have taken biopsies of the artery several months after the procedure in the process of using the artery as inflow for a cross femoral bypass, and the artery clamped and sewed like a normal artery and the pathology returned normal artery.

This has several advantages over conduit creation which can be a morbid and high risk procedure in patients who require minimally invasive approach. A graft is avoided. The artery is over 8mm in diameter where with stenting up to 8mm with an occlusive plaque, the danger of rupture is present, and often ballooning is restricted to 6mm-7mm. This is insufficient for many TEVAR grafts and TAVR valves.

For patients being worked up for living related donor transplants who are turned down because of the presence of aortoiliac plaque, those with the right anatomy can undergo this procedure and potentially become candidates after a period of healing.

 

Park Clamp

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One of the reasons why I moved my family to Cleveland was to participate in innovation at the Clinic. One of the devices that I have been working on has reached the patent stage and I am free to divulge it. Full link below. Innovation is part of the culture here like oxygen in the air.

Clinic link