Categories
AAA Commentary techniques

The Parallel Bar -higher than you’d think

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At last week’s Veith Symposium, there was a straw poll for parallel grafts versus fenestrated stent grafts in emergent setting, and the results were a populist parallelist majority. This is clearly the result of years of inability to access this technology and reflects market forces making the decision over careful science. There are clear examples of this in the past -the adoption of laparoscopic cholecystectomy and appendectomy, done without randomized control trials shows that RCT’s be damned, people and surgeons will get what they want.

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The several presentations on parallel grafts caught my eye. First was the Eye of the Tiger technique which sounds like a kung-fu move. Presented by Dr. David Minion of the University of Kentucky, the gist of it is that the gutters created by parallel grafts can be obviated by reshaping the branch grafts from circles to lenticular shapes (illustration). The sequence of moves is to deploy a balloon expandable stent graft outside of the main graft and deploy it, then deflate the balloon. The aortic graft is then ballooned, crushing the branch graft. With the balloon inflated, the branch graft is then inflated, now taking a lenticular configuration. This, I will put in my tool box.

Bullfrog catheter tracking (top) and inflated for infusion (botton) with needle out.
Bullfrog catheter tracking (top) and inflated for infusion (botton) with needle out.

The other presentation was on the bullfrog catheter, by Dr. Christopher Owen of UCSF. It inflates to press the catheter portion of it in the middle of the length of the balloon against the stent graft wall. A penetrating needle then comes out through the graft material, allowing for infusion of a sealing embolic material. This has not been tried in humans but application in an animal model is ongoing.

The first time I saw Nellix, this is what I thought...
The first time I saw Nellix, this is what I thought…

I have a feeling parallel grafts will be with us for a while. Using these in conjunction with the Nellix graft, juxtarenal aortic aneurysms were treated, which brings me to think that with the inevitable progression of paravisceral segment aneurysm disease, we will be seeing secondary endobags (not a pejorative) for treatment of paravisceral aortic aneurysms with parallel grafts, and we will see something like this on CT scans one day (illustration). Mr. Ian Loftus of St. George’s Vascular Institute reported on 19 patients (11 single, 5 double, 3 triple branch) over 12 months who were unsuitable for OR/EVAR solutions, treated with 100% technical success, one type I endoleak. Dr. Michel Reijnen presented the Arnhem experience with this technique. Their series included 7 patients with juxta (5) or para (2) renal AAA’s (4 single, 2 double). He reported 100% chimney graft patency and no reinterventions in short followup. He presented a case of rupture, but warned that further investigation would be needed before using the endobag for rAAA.

I think that the whole issue points to several truths. Paravisceral and thoracoabdominal aortic aneurysms have always been viewed with trepidation and this generally caused referral of these cases to high volume centers and surgeons during the open era. Experience with EVAR has infused a sense of confidence and with mastery of infrarenal EVAR and basic endovascular interventions, most practitioners feel ready to offer an endovascular solution to the visceral segment AAA’s, but feel locked out either through lack of training or inability to access the devices, particularly not having ready solutions on the shelf. These parallel graft systems offer relative ease of delivery and use readily available components. Even I have resorted to parallel grafts in an emergency with acceptable short term result (patient lived) but with uncertainty with durability.

I think that there will never be a completely satisfactory off the shelf, “every-surgeon” solution because these patients are no less complex when approached with endovascular technique -they just present a different set of equally difficult challenges. As in open repair of these complex aortic aneurysms, endovascular repair of these should aggregate to high volume practices and centers with deep experience.

Categories
bypass PAD techniques

Tibial Endarterectomy in Conjunction with Popliteal Endarterectomy in Lieu of Bypass

 

The patient is an elderly woman who had severe rest pain due to popliteal artery and tibial occlusion. She had no leg veins and sparse arm veins which would have to be spliced to achieve a femoro-peroneal bypass. Her preop CTA showed a patent SFA and proximal popliteal artery occluding above the joint and reconstituting only the peroneal artery. I planned for a retrograde popliteal remote endarterectomy tibioperoneal trunk endarterectomy via a below knee exposure with patch angioplasty of the arteriotomy, the bailout would be a short arm vein bypass from the above knee popliteal artery to peroneal artery.

Arteriography was performed via a left common femoral access and is shown below.

The popliteal artery was occluded and there was a very small peroneal artery that continued down the leg with seeming occlusion of the anterior and posterior tibial arteries. The popliteal and anterior tibial artery were exposed through a below knee incision taking care to avoid venous injury which can be troublesome source of bleeding. The tibioperoneal trunk down to the bifurcation and origin of the peroneal artery was exposed through the same incision. And anterior tibial artery origin was controlled with a vessel loop largely out of habit although it seemed clear it was occluded, as were the proximal popliteal and tibioperoneal trunk branches. The arteriotomy was created from the tibioperoneal trunk to the popliteal artery and endarterectomy was performed from distal to proximal to create a starting point for the ring dissectors used in remote endarterectomy. The anterior tibial plaque branched off much like an external carotid artery plaque and I decided to see what would happen if I did an eversion endarterectomy. I was able to mobilize a short length of the artery and was able to pull as I endarterectomized around the plaque and it thinned very nicely and came out with a gossamer end point. More gratifyingly, the backbleeding was excellent –this was controlled with the vessel loop very nicely. The retrograde popliteal endarterectomy was performed as described in another post in another case –link. The artery was then patched and completion arteriography was performed.

What was fascinating was it seemed I had reopened not just the pop-peroneal axis but the anterior tibial artery was also open, very dramatically so. The patient also had a bounding dorsalis pedis artery pulse. She recovered and went home two days later and in three years of followup while I was still in Iowa, she remained widely patent, maintained on Coumadin anticoagulation.

Popliteal endarterectomy for localized popliteal artery disease has been described (reference) with decent short term patency and successful limb salvage. Nasr et al. performed their endarterectomy via a posterior exposure. I think I recall coming across this in a book chapter from the old Wylie textbook which is long out of print. I think that the anterior tibial artery never lit up well because it was part of a highly developed collateral network, but it was patent all along. Duplex which was not done, would have given a better indication of its patency. I think that the patency of the popliteal endarterectomy is related to its relative shortness and in this case, the added outflow cannot hurt.

Reference

Nasr H et al. Popliteal endarterectomy for localized popliteal artery disease. Ann Vasc Surg 2014 (in press).

 

 

Categories
Uncategorized

Poster session -Dr. Teng presents poster about using cephalic vein transposition for SVC Syndrome

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Dr. Teng, second from left, supported by her co-trainees, presented a poster at the International session on using cephalic vein transposition for SVC Syndrome, which was well received.

Categories
bypass techniques

Nice source of arterial autograft for pediatric cases

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Dr. Gary Fass presented a decade long series of safe autograft harvest using SFA harvested for arterial bypass while reanastomosing remnant SFA to the PFA, achieving acceptable long term patency. This will definitely go into my armamentarium. Shows the poster sessions are often very useful!

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Categories
AAA bypass techniques

Hybrid graft suture less technique for visceral branches during open thoracoabdominal aortic aneurysm repair.

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Dr. Roberto Chiesa from Italy presented his experience in 61 renal arteries using the Gore hybrid graft today at the Veith Symposium The graft which I sketched above on my phone is their PTFE graft terminated in a Viabahn configuration. He reports a 10% acute renal failure rate and 90% primary patency in followup. This is something I’ve considered but never tried because the one extra anastomosis doesn’t add all that more time especially if a branched graft is used. Will revisit this concept.

Dr. Debus presented using this graft in a later talk for debranching visceral arteries in hybrid repair of TAAA.

Categories
AAA peripheral aneurysm

Consult QD post regarding iliac branched grafts

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Link to Clinic blog post regarding iliac branched grafts (link).

Categories
Uncategorized

The Time I Crashed the VEITH Symposium

One of the many conversations I had with Dr. PJ O’Hara, who just recently retired, was about the place of traditional open vascular surgery. It is well known that many vascular surgeons are graduating with only a handful of open aortas. The idea of creating an open vascular (exovascular) fellowship was actually floated among the society leadership, but I suspect it was mainly the kind of idea that occurs when seasoned surgeons get together for a beer. This CTA above shows the kind of aneurysm that still benefits from open repair. It is a juxtarenal AAA with a highly angulated, short neck. This was one of the cases I did in my last practice. The patient did very well and went home on POD #5. A CT was done at a later date for possible dissection (there was none) but I got to check out my work (below).

Unlike my patients who undergo EVAR, this patient won’t need intensive lifelong followup. While there is a small rate of complication in the mid and long term with open repair, these are infrequent and frankly rare. This is in contrast to the demands, often spelled out in the IFU’s, of stent grafts that require imaging and followup at 1 month, 6 month, 12 months, and annually for life. This is usually a CT scan and ultrasound, plus time and travel. While this is usually an agreeable tradeoff to most patients who are easily frightened by open aortic surgery, the cost to our healthcare system is not trivial.

The DREAM trial showed that the benefit of EVAR versus open repair is lost after a year. Most of the benefit is in the short term –in hospital stay, complication rates, and recovery time. EVAR also allows more surgeons and even nonsurgeons to treat aneurysms. Clearly, for the higher risk patients, the extra year or two of complication free life is worthwhile and avoiding possible death from open aortic surgery may be a good thing, but for the majority of patients, we still have to ask far more and far better from the technology. This starts with getting reintervention rates closer to zero and significantly diminished followup protocol printed on the IFU. It also means allowing it to cost the same as open surgery. It probably means changing the way we assess and approve medical devices.

My personal journey through the past twenty years since I started my career (I was an intern in 1994!) has been a witness to vast changes in how we treat vascular diseases. Vascular surgery was more art than science, and many fellowships were indentured servitude to a famous surgeon, usually with a fearsome reputation. There was selection pressure in the process for certain personality types – fanatically committed to received wisdom and suspicious of change. Frankly, I was not a good fit, being relatively open minded, suspicious of dogmatism, and always looking for a better way.

There was an industry sales representative back those Manhattan days. David Hunt took an interest in the peons and always brought in the best food and swag –I know this is verboten these days, but I’m talking about history here. He brought in needle holders and sutures, and trays for holding grafts for practicing anastomoses, which I did practice on those interminable weekend calls up in our Stuyvesant 10 call rooms. When you ran out of grafts, a call to Dave, and he’d bring in several bags of graft (PTFE). Clearly, the crack dealers and lobbyists didn’t have a monopoly on this sort of sales technique.

One day, he brought in stent grafts –something out of the labs, and mockups of AAA’s. My mind reeled playing with EVAR. This was the future. That fall, I pulled some favors and left work early, and got to the Hilton wearing a blazer over my scrubs. Sneaking into the Veith Symposium, I was shopping my own future. I walked around the halls laden with all kinds of stent grafts and mock ups of space age operating rooms with fluoroscopy built into them. Dodging the security, I snuck into lectures and listened to the early data, and the resounding condemnation of the angry old men. I had to be part of this. This was supercool. This was the future.

I wasn’t alone in this endo-enthusiasm. A whole generation of vascular surgeons fell into its spell. There was the urgency of training to avoid the perceived obsolescence of not being able to perform endovascular procedures. Back then, it was very difficult to get training and subsequently privileging to do endovascular. I had the great fortune of working with Dan Clair while we were at Columbia in the early 00’s.

Even back then, I also perceived a rush to cast off open surgery, even in myself. There was a thrill at crossing a long SFA occlusion with a wire. It felt like victory sparing someone a long vein bypass operation. Every year, new gadgets came along to make the crossing and opening of closed arteries slicker and easier. But the truth echoed in the condemnations of the angry old men, many who were at this point retiring en mass, was that most of these procedures weren’t very durable. Where a vein bypass would be good for years, these interventions were sometimes only good for a few months. Many practitioners, usually not vascular surgeons, vocalized that two or three of these procedures was better for the patient than any single huge operation, and (sotto voce) was better for the revenue stream. Procedural failures definitely put water on the fire, especially after the news that many of the investigators for these new devices were also investors.

Endo-enthusiasm grew into eventually a more mature perspective. Which brings me to the point of this meandering entry. I see the best results when the range of potential therapies are tailored for the needs of the patient. A frank discussion about the short, mid, and long term outcomes of any approach allows for a deliberative planning discussion that many patients, especially those who come with literature and research in hand, appreciate. This can only be possible with a practitioner who has mastered both endo and exo– vascular techniques.

I tell people who are applying for vascular surgery training that one of the best metrics for judging a program is the volume of hybrid procedures being performed. It speaks to an ease with all possible techniques and a philosophy based on imagining the best possible path for treating a patient. While there is nothing wrong with seeing programs and practices with an “open guy” or “gal” and the “wire guy” or “gal,” there will be an abundance of both endo and exo-enthusiasm, that is bias.

I believe that this secures the future of vascular surgery. Other specialties can generate unlimited number of endovascular specialists, but only vascular surgery can produce the individual who can perform a redo common femoral endarterectomy, profundaplasty, endovascular aortoiliac recanalization, and infrageniculate vein bypass to save a leg and a life. Only vascular surgery can produce the individual who can judge that with any credibility that limb salvage attempts are likely to fail and recommend primary leg amputation and rehab and have the patient walking on a modern prosthetic limb within a month, and maybe even running within a year. And that same surgeon can perform a tibial intervention to heal an ulcer, and understand that it only needs to stay open 6-12 months and forebear reintervention when the artery is closed and the patient healed and asymptomatic.

So I head to the VEITH symposium looking forward to seeing what’s next. I have a badge this time.

 

 

Categories
MALS

The Median Arcuate Ligament Compresses the Celiac Plexus -Pathoanatomy

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This is a picture from several years ago when I released the median arcuate ligament with open surgery. Seen tented up by the right angle clamp is the fibromuscular tissue over the celiac axis. You can also see a cord of celiac plexus, which gives the foregut somatic sensory innervation. It is becoming clearer that MALS is a nerve compression syndrome in the same way that carpal tunnel compression of the median nerve or thoracic outlet compression of the brachial plexus causes pain. Like nTOS, the arterial compression is a bystander, but a necessary finding in the diagnosis. The celiac axis and median arcuate ligament acts as a nerve compressor. This is why people with MALS respond to celiac plexus block and why it makes sense they don’t have mesenteric ischemia.

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Categories
Carotid

Another Carotid Body Tumor, A Shamblin I, From My Archives

These really are common in the Midwest. When I was a fellow, about one a month was done at the other Clinic. Shamblin, who ironically never went into vascular surgery, wrote the paper with the eponymous classification while a medical student.

October 16, 2008

This patient underwent a screening carotid artery duplex scan, and was found to have a 15mm mass in his carotid bifurcation. He was asymptomatic. On exam, there was a nodule that was palpable through the skin.

He was taken to the operating room with myself and Dr. Simon Wright, otolaryngologist, and we found a small discrete mass basically as anticipated on CT. The incision was along skin lines, and all the nerves were dissected using McCabe clamp. Hemostasis was maintained with sutures, clips, and a harmonic scalpel which was used to avoid transmission of electrical energy into the wound.

 

The mass gets its perfusion from multiple branches from the external carotid artery. By patiently dissection these, the tumor was dissected and removed. This was a Shamblin Type I lesion (see blog entry). The patient recovered without complication and was discharged the next day.

The panel below right shows the screening carotid duplex study which found the lesion. The CTA above shows the lesion in its typical location. The oblique axis MPR view shows the mass to have multiple vascular supply, but to be discrete and not invading the artery. The photos above show the lesion in-situ and ex-vivo.

Path revealed it to be a paraganglionoma.

Categories
Journal Club

December Journal Club

The November Journal Club was held with great attendance from the staff. Dr. Roy Miler was awarded the prize for most symposium-ready talk. December Journal Club will be held December 16, 2014 at Foundation House. The topic is thrombolysis, which has a rich history here at the Clinic. The papers to be discussed are:

 

Xiaoyi Teng, MD: Freischlag vTOS lysis

Lynsey Rangel, MD: TOPAS NEJM

Francisco Vargas, MD: CAVENT Trial