Life imitates social media: a ruptured type V thoracoabdominal aortic aneurysm or IT saves a life

ARTERIAL (2) (2)
Type V TAAA Rupturing into Right Pleural Cavity

It was only last month when I came across a post of an aortic aneurysm in a difficult spot (link) and I couldn’t help chiming in some comments. Reading it now, I sound insufferable, because I wrote,

“Depends on etiology and patient risk stratification. Also assuming aneurysm goes to level of SMA and right renal artery origins and involves side opposite celiac. Options depending on resources of your institute: 1.Open repair with cannulation for left heart bypass and/or circulatory arrest 2.Open debranching of common hepatic, SMA, R. Renal from infrarenal inflow and then TEVAR 3.FEVAR from custom graft from manufacturer on protocol 4.Parallel grafting to CA, SMA, R. RA with TEVAR 5.Surgeon modified FEVAR 6.Open Repair We would have a multidisciplinary huddle around this patient -Vascular, Cardiac Surgery, Cardiology, Anesthesia, and ID (if needed) to help choose. Be ready to refer to a center with more resources -including prepping patient for transfer and imaging -including uploading images to the cloud for transfer with patient’s permission. More info please”

More Info Please, Indeed

The post I commented on was of a saccular aneurysm in the transdiagphragmatic segment of aorta. Ironically, only a few weeks later, I got called from hospital transfer center about a patient with a leaking aortic aneurysm, a type V thoracoabdominal aortic aneurysm as it turned out, from an outside hospital, needing urgent attention, and we accepted in transfer based on the conversation I had with the tranferring physician. And that was the problem -usually in taking these inter-hospital transfers, you have to pray that the precious CT scans come along with the patient burned correctly onto a CD-ROM. You can buy and watch a movie in 4K resolution over the internet -about 4 gigabytes, but a patient’s CT scan which is about 200 megabytes -because of various self imposed limits, overly restrictive interpretations of laws, and lack of computer skills, these life saving images get transferred on CD in 2019. That last time I purchased a CD for anything was over 15 years ago.

An Interested Party

The technical solution –to use the internet to transfer critical life saving information between hospitals – came about when our IT folks took an interest in my quarterly complaint email about using the newfangled internet for sharing files. After mulling various solutions ranging from setting up a server to using commercial cloud solutoins, we came upon the compromise of using our internal cloud with an invitation sent to the outside hospital. I would send this invitation to upload the DICOM folder of the CD-ROM to an outisde email address. It was simple and as yet untried until this night. “Would the patient agree to have his CT scan information transmitted to us electronically?” I asked the other physician. He assured me that the patient was in agreement.

It Takes Two to Tango

Of course, being able to transfer these pictures requires a willing partner on the other side, and the referring physician made it clear he did not have the technical expertise to do so. It took a bit of social engineering to think about who would have that ability. Basically, aside from myself, who spend all their time in dark rooms in the hospital in front of giant computer monitors? The radiologists! I got through to the radiologist who had interpreted the report and explained the simple thing I needed. Gratefully, he agreed, and I sent him a link to our cloud server. I explained to him, “When you receive this, clicking the link opens a browser window and then you open the CD-ROM and find the DICOM folder and drag and drop it on the browser window.” The 200-500 megabytes of data then get sent in electronic form, as it was meant to in 2019.

The Internet Saves a Life

The brutal truth is that in locking down a computer system, many hospitals make it impossible to even load an outside CD-ROM, creating many self imposed barriers to care. Thankfully, at CCAD, we were able to work together to find a secure solution. With the CTA on our servers, I was able to review the study within 15 minutes of accepting the patient, and arrange for the right team to be assembled, and confirm that we had the right material (stent grafts) for treating the patient. When the patient arrived, OR was ready to go, saving hours of time that normally would have been required if the CT scan had to be reviewed from the CD-ROM that came with the patient. Sometimes, the CD-ROM does not come, and in a critical situation, the CTA has to be repeated with some risk to the patient for complications of the contrast and radiation.

What to Do

The patient had a 8cm sphere shaped aneurysm arising in the transdiagphragmatic aorta, leaking into the right pleural cavity.

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The patient was otherwise a healthy middle aged man with risk factors of smoking and hypertension. The centerline reconstructions showed the thoracic aorta above the aneurysm to be around 20mm in diameter and same below, with the celiac axis and superior mesenteric artery in the potential seal zone of a stent graft. The only plaque seen was around the level of the renal arteries and was focal and calcified. Looking at the list I had made as a comment to the Linked-In post, I realized that I really only had one viable option.

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Open repair, usually the most expeditious option, was made challenging by the right hemothorax, making a left thoracotomy hazardous if the lung had to be deflated. Cardiopulmonary bypass would have to be arranged for, and that adds a metabolic hit that greatly raises the stakes. Of the endovascular solutions, the only viable option was TEVAR to exclude the rupture and debranching of the celiac axis and superior mesenteric artery. To those who would advocate for parallel grafts, there was no room in the normal 20mm diameter aorta. And branch systems for rupture are some time in the future. Also, the patient was becoming hypotensive. So the planned operation was first TEVAR to stop the bleeding, and then open surgical debranching. A hybrid repair.

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The smallest stent graft we have is a 21mm graft, but it would not be suitable for this aorta. In practice, the normal aorta is quite elastic and will dilate much more than what is captured on a CTA. The next size we have is 28mm graft and I chose this to exclude the rupture, which was done percutaneously.

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As seen below, the graft excluded the celiac and SMA. Late in the phase of the final aortogram (second panel) there was an endoleak that persisteed despite multiple ballooning. The timing suggested the intercostals and phrenic vessels contributed to a type II endoleak, but it was concerning.

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Find the Endoleak

The bypasses were sent from the infrarenal aorta to the common hepatic artery and the SMA close to its origin, and the origins of the celiac axis and SMA were clipped. The bypasses were then done with a 10x8mm bifurcate Dacron graft originally for axillofemoral bypassing. It had spiral rings which I removed at the anastomosis and this resulted in a kink at the closer bypass. Usually, I loop this for iliomesenteric bypass but there was not enough distance from the infrarenal aorta. I have to add a little trick I modified from my pediatric surgery experience as a resident -a Heinecke-Mikulwicz graftoplasty:

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This worked to relieve the kink as evidenced on the aortogram above. After closing the laparotomy, I placed a chest tube in the right chest. The patient had a course prolonged by a classic systemic inflammatory response syndrome, with fevers, chills, and leukocytosis. He bled for a while but stopped with correction of his coagulopathy. All blood cultures were negative, but a CT scan was performed out of concern for the endoleak, and the possibility of continued bleeding.

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No endoleak was detected as the sac was fully thrombosed. There was a consolidation of the blood in the right chest, but it resolved with fibrinolytic therapy.

Discussion

This case illustrates several points I have been making on this blog.

  1. Hybrid repairs are not some kind of compromise but the full realization of a complete skill set. When students ask me how to judge a training program, one of the best metrics is how frequently are hybrid operations performed. It means either the endovascularist and open surgical operator are in complete synchrony or there are individual surgeons competent in both open and endovascular surgery. Hybrid operations, rather than being a compromise, are an optimization.
  2. Time -Laying the stent graft across the celiac and SMA origins starts a warm ischemia clock. The liver and intestines, in my reckoning, should be able to tolerate the 2 hours of work to get the bypasses working. Cardiopulmonary bypass may give you less ichemia but at the metabolic cost of the pump time. These negative factors add up, but were surmounted by the fact that early control of hemorrhage was achieved. Stopping the bleeding and restoring flow are the core functions of vascular surgery.
  3. Planning and preparation. The ability to see the CT images and prepare the teams and materiel before the patient transferred was lifesaving. This is where our IT gets credit for responding to a critical need and formulating a solution that meets internal policies, external regulations, and saves a life. It illustrates so many opportunities particularly with electronic medical records and their processes which focus more on documentation for billing. A discharge summary should be multimedia like this blog post and it should be normal and easy to generate. And finally, as clinicians, we should mind technology with as much attention as we give to the latest medical devices and techniques.

When Hybrid Seems Better: Carotid Trauma As a Model For All Trauma

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Tracheal deviation due to iatrogenic carotid pseudoaneurysm

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, neck zones.pngwhich 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:

  1. Open repair
  2. Endovascular repair from femoral access
  3. 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.

carotid control

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.

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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.

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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.

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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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

post CTA EVAR-ENDORE

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

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

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

 

Reference

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

Complex femoral pseudoaneurysm with arteriovenous fistula and large hematoma treated with novel hybrid therapy

wide avf and pseudo

The patient is a middle aged man who after an interventional procedure was referred to my clinic with an expanding hematoma due to a pseudoaneurysm complicated by an arteriovenous fistula. He was a week out from his procedure and had grown a hematoma roughly the size of a hard boiled egg in his left groin which caused him pain. A duplex scan showed a pseudoaneurysm (below) with fistula flow.

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On examination, he had this well circumscribed indurated hematoma of hard boiled egg size with tenderness. There was a bruit on auscultation. Duplex showed a small chamber of flow adjacent to the proximal superficial femoral artery emptying into the femoral vein. Doppler in the common femoral vein showed relatively high fistula flow, and this is reported to be associated with failure of thrombin injection. CTA (top) demonstrated flow of contrast from femoral artery to vein through a pseudoaneurysm chamber that laid between. Angulation to an axial orientation showed this better (below).

axial AVF
Contrast flows from femoral artery (right) to the fistula chamber, then into the femoral vein.

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Axial MPR
Operation was planned, but in the days leading up to the operation, I had a thought -the primary reason why ultrasound guided thrombin injection would fail is the AVF. It would be simple to fluoroscopically guide an angioplasty balloon on the arterial side to occlude the fistula inflow. The next step would be to get access to the pseudoaneurysm with a needle under ultrasound guidance, confirm location with a contrast injection. Once confirmed, the balloon is inflated and a small volume of thrombin would be injected. I discussed this with the patient in detail and he was enthusiastic about trying this before proceeding with an open repair.

 

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Schematic of procedure
The procedure went as planned. Ultrasound guided access is aided with dual live display of B-mode and color flow (below)

Arteriography showed much of the contrast from injection of the pseudoaneurysm to preferentially go to the artery which made me worry less about creating a DVT/PE. With balloon inflated (below), thrombin was injected and balloon inflation held for about 30 seconds.

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There was resolution of flow in the pseudoaneurysm and in the fistula. Before and after duplexes are composited below.

prepost pseudo chamber

Repeat duplex on the following day showed resolution of the pseudoaneurysm and arteriovenous fistula.

In the days before ultrasound guided thrombin injection of pseudoaneurysms, open surgical repair of these was fraught with complications. First, these patients typically had cardiac disease. Second, they were usually anticoagulated often with multiple agents. And finally, they were  many times obese, making not only the operation fraught with complexity, but the ultimate wound healing a delicate and rare phenomena. Even now, we get emergency repairs when access hemostasis fails, and these patients are typically high risk. With hematoma evacuation, inflammation, lymph leaks, and infections may follow; the patient was correct in his enthusiasm for agreeing to proceed with a minimally invasive effort.

As to the techniques, they are all well established in the vascular surgeon’s toolbox. Ultrasound guided access of the pseudoaneursm should be obtained before arterial occlusion. This was  facilitated by general anesthesia which kept the patient from moving. Having access to excellent ultrasound and angiographic imaging made this possible. The patient felt much better and was discharged home the next day after his confirmatory duplex.