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.

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.

When good enough is better than perfect: a case of end stage visceral segment aortic occlusive disease

The patient is a woman in her 60’s who self referred for complaint of abdominal pain, weight loss, and rest pain of the lower extremities. She is a 40 pack year smoker and had severe COPD, hypertension, congestive heart failure with mitral regurgitation, chronic kidney disease stage IV, and ischemic rest pain of the legs. She had a 30 pound weight loss due to severe postprandial abdominal pain. She had bloody stools. Her kidney function was worsening, and dialysis was being planned for likely renal failure but she was against dialysis. She had consulted several regional centers but was felt to be too high risk for surgery and with her refusal of dialysis, would be a high risk for renal failure and death with intervention. Physical examination revealed weakened upper extremity pulses, and nonpalpable lower extremity pulses and a tender abdomen. In clinic, she developed hypoxia and dyspnea and was admitted directly to the ICU.

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CTA (above) revealed severely calcified atherosclerotic plaque of her visceral segment aorta occluding flow to her mesenteric and renal arteries and to her leg. The right kidney was atrophic. The left kidney had a prior stent which looked crushed. The infrarenal aorta was severely diseased but patent and there were patent aortic and bilateral iliac stents.

Echocardiography revealed a normal ejection fraction of 60%, diastolic failure,  +2 to+3 mitral regurgitation, and pulmonary artery hypertension. She did respond to diuresis and stabilized in the ICU. Intervention was planned.

Options that I considered were an extranatomic bypass to her legs and revascularization from below. I have come across reports of axillo-mesenteric bypass, and I have performed ascending and descending thoracic aorta to distal bypass for severe disease, but concluded, as did the outside centers, that she was a formidable operative risk. Also, there was a high likelihood of great vessel occlusive disease. Looking at her CTA, I felt that she needed just a little improvement in flow -not perfect but good enough. The analogy is like drilling an airline through a cave-in. Also, her left kidney gave a clue -it was normal sized and survived the stress test of a contrast bolus for the CTA without dying. A discussion with the patient green lighted an attempt -she understood the cost of failure but did not wish to linger with this abdominal pain.

Access for intervention was via the left brachial artery. Aortography showed the severe stenosis at the origin of the SMA and the nearly occlusive plaque in the visceral segment aorta.

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The plaque was typical of the coral reef type, and had an eccentric channel that allowed passage of a Glidewire. Access into the left renal artery was achieved. Its stent was patent but proximally and distally there were stenoses; this was treated with a balloon expandable stent. The path to it was opened with a balloon expandable stent to 8 mm from femoral access. This was the improvement the renal needed. A large nitinol stent was placed from this access in the infrarenal aorta when severe disease above the iliac stents was encountered.  The SMA was then accessed and treated with a bare metal stent.

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Renal stent was reaccessed and ballooned in this pentultimate angiogram

Her creatinine improved, as did her intestinal angina. She was discharged home. She later returned a month after the procedure with complaints of nausea and vomiting and right lower quadrant abdominal pain and was discovered to have an ischemic stricture of her small bowel. This was removed laparoscopically and she recovered well. She recovered her lost weight and now a year and a half later, remains patent and symptom free.

Discussion: Dr. Jack Wiley includes in the preface to his atlas of vascular surgery the words of Dr. Joao Cid Dos Santos, the pioneer of endarterectomy techniques, “Vascular surgery is the surgery of ruins.” And in that context, good enough is sufficient.

 

Visceral Mycotic Aneurysm Treated with Resection and Revascularization

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Sometimes the best conduit is no conduit.

The patient presented with abdominal pain and fevers which was initially diagnosed as a urinary tract infection. He is an older man with a prosthetic aortic valve and prostatic cancer who had a Foley catheter for several weeks leading up to a prostatectomy. Antibiotics relieved his abdominal pain. Echocardiogram revealed aortic valve vegetations. A CT scan revealed a mycotic mesenteric aneurysm and vascular surgery was consulted.

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Examination revealed moderate cachexia and a soft abdomen. He was taken to the operating room for resection of aneurysm. Laparotomy revealed a mass in the small bowel mesentery root. The aneurysm had moderate but not excessive amounts of inflammation.

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The CTA had shown the superior mesenteric artery to be patent above and below what was likely an embolized vegetation (see white arrows in all images).

The treatment goal was aneurysm resection with an intraoperative determination of need for revascularization. His thighs were prepped for possible saphenous vein harvest and cryopreserved artery was available.

Resection revealed the artery to be infected. There was good backbleeding from the distal SMA.

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The handheld Doppler signals in the distal segment of SMA were excellent, corresponding to the viable bowel, but the patient’s cachexia and relative inanition concerned me for future bowel ischemia complicating his planned redo aortic valve replacement and subsequent prostatectomy.

But before I embarked on vein harvest, a simple maneuver determined my next step. I brought the distal SMA to the proximal SMA and found there was enough laxity to simply anastomose both to each other.

IMG_4654The flows were now excellent in the SMA. The patient recovered uneventfully, requiring no subsequent bowel resection. He then had his redo-aortic valve replacement from which he recovered well from and ultimately soon after had his prostatectomy.

Treatment with antibiotics without resection is not a good option as the majority of these rare aneurysm go on to rupture if left unresected. A frequently cited article by Drs. DeBakey and Cooley from 1953 (ref 1) and other subsequent articles show success with simple resection. While cryografts and saphenous vein grafts are subject to infection, they can be used safely in this setting, but the best conduit using no conduit. Often, aneurysms start at a small nidus and not only expand but elongate, given an opportunity to repair aneurysms primarily.

Reference

  1. DeBakey ME, Cooley DA: Successful resection of mycotic aneurysm of superior mesenteric artery: case report and review of literature. Am Surg 1953;19:202-212.

The inferior mesenteric artery is a poor target for revascularization in chronic mesenteric ischemia

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The patient was referred to me after having undergone an intervention for chronic mesenteric ischemia. She is over 70 years of age and had lost over thirty pounds in 3 months due to severe abdominal pain with eating. A month prior to seeing me, she had undergone arteriography at an outside hospital and was found to have occlusion of her celiac axis (CA) and superior mesenteric artery (SMA) with a small but patent inferior mesenteric artery. Attempt at recanalization, done from left brachial access, of the SMA was abandoned after the patient started having pain, and the inferior mesenteric artery was accessed and stented with a balloon expandable stent. Despite the stent, the pain persisted. On examination, she was cachectic, weighing about a hundred pounds, and had moderate to severe pain with abdominal palpation. CT angiography (shown above) showed a chronically occluded CA and SMA and a patent stent to the IMA.

After discussion with the patient about the possibility of a bypass, we decided to proceed with diagnostic arteriography and an attempt at recanalization. When planning these, I always try to come from the groin first as most of the time I am able to revascularize from below. I try to avoid 6F sheaths in the arms of thin cachectic patients -women especially where the brachial artery is likely the same diameter as a 6F sheath. The only downside about coming from below is that it is technically challenging and the stent comes off at a higher angle than the SMA typically has in situ.

The image below shows the procedure:

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The series of images shows the initial aortogram and access. The superior mesenteric artery has a stenosis at the origin, with an area of post stenotic dilatation or small aneurysm, which occludes beyond the first three branches of the SMA. The IMA fails to feed the bowel -the later phases not shown shows filling from the SMA segment to the CA and ileal branches.

The key step to this procedure is in getting “deep” access with a wire -in this case a floppy Glidewire, which I used to cross the occluded SMA. There is feedback from the tip which occurs if you spin it without a torque device. The wire has the quality, a feature really, of being tacky when dry, allowing for a great deal of coaxial spin with your first two fingers and your thumb. The tip transmits information about what it is crossing as you spin it -this is something that is hard to teach at first, but is gained largely through experience, but I learned it from Dan Clair over a decade ago when he barked at me to get rid of the torque device (“a tool for babies!”). The tip will go where it should if you spin, not push.

Once the wire is buried, a suitable catheter that tracks well is brought across the occlusion. Again, while there are many catheters that can do this, the Glide Catheter is suitable again from spinning across an occlusion over the wire that would push out the lowest profile and equally hyrdophillic catheters. Once the catheter is buried, a suitably stiff wire (in this case a Rosen wire) should be brought across -this widens the arc created by the wire as it goes up and over the SMA origin and allows for delivery balloons and stents. Using the balloon-piton technique (a requisite for FEVAR), the sheath is brought into the SMA, securing access into it.

The occlusion in the mid-SMA ballooned nicely and did not require a stent -a nonocclusive dissection is seen but I chose not to treat this as placing a stent is likely to cause as many problems as solve and the dissection is in line with flow. The origin was stented with a balloon expandable stent -having the patient awake is useful in determining if the stent is “big enough.” Final arteriography in two planes is shows below.

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Gratifyingly, the entire mesenteric system in the CA (foregut) and SMA (midgut) lit up. I admitted her for observation as I have seen patients develop bowel infarction with reperfusion which may be due to embolization but I think just as likely due to edema. Food needs to be reintroduced slowly as there maybe metabolic consequences to rapid refeeding. Her baseline lactate was 2.6mMol/L but came down to 0.8mMol/L the next day. Her other labs were normal. Her pain remitted and she was able to tolerate a regular diet by postoperative day 2.

Discussion: 

Mesenteric ischemia is a particularly morbid condition. When it presents acutely, there is a high mortality rate (ref 1). Revascularization in good risk individuals is still bypass surgery (ref 2,3). The inferior mesenteric artery offers a dismal revascularization target for this reason -while the artery will remodel and dilated in the setting of mesenteric ischemia, its orifice from the aorta does not and is usually no more than 1-2mm from birth to adulthood. Also, while the large bowel will get perfusion from the IMA, and the foregut may get collateral flow from collaterals fed from the middle colic via the Arc of Riolan, the midgut does not get sufficient flow from from the IMA because it requires the longest path to fill the ileal and jejunal branches. The development of atherosclerosis in the aorta further complicates attempts at stenting. Despite this, it is still attempted (ref 4) and in 4 patients was successful at relieving pain for short periods of time, with one patient requiring eventual bypass despite characterization as “high risk.” It is a reflection of how poorly this vessel does with intervention that this 4 case series is the largest in the literature.

The analogy to IMA stenting in the legs is stenting of a heavily diseased profunda femoral artery in the setting of critical limb ischemia with femoropopliteal occlusive disease. It is occasionally successful in the short term, but will only delay the inevitable operation. There are no low risk patients with severe weight loss due to mesenteric ischemia. Aggressive intervention offers a path of survival for these patients, and but long term results are only possible with bypass.

References

  1. Park WM, Gloviczki P, Cherry KJ Jr, Bower TC, Panneton JM, Schleck C, Ilstrup D, Harmsen WS, Noel AA. Contemporary management of acute mesenteric ischemia: factors associated with survival. J Vasc Surg. 2002;35(3);445-452.
  2. Park WM, Cherry KJ, Jr, Chua HK, Clark RC, Jenkins G, Harmsen WS, et al. Current results of open revascularization for chronic mesenteric ischemia: a standard for comparison. J Vasc Surg. 2002;35(5):853–859.
  3. Kasirajan K, O’Hara PJ, Gray BH, Hertzer NR, Clair DG, Greenberg RK, et al. Chronic mesenteric ischemia: open surgery versus percutaneous angioplasty and stenting. J Vasc Surg. 2001;33:63–71.
  4. Wohlauer M, Kobeiter H, Desgranges P, Becquemin JP, Cochennec F. Inferior Mesenteric Artery Stenting as a Novel Treatment for Chronic Mesenteric Ischemia in Patients with an Occluded Superior Mesenteric Artery and Celiac Trunk. Eur J Vasc Endovasc Surg. 2014;27(3):e21-e23.