Categories
amputation bypass Commentary PAD trauma

When Better is Better Than Good

original bypass

The dictum that better is the enemy of good is one of the old chestnuts carried around surgery training forever. It is an admonition against an unhealthy perfectionism that arises from either vanity or self doubt, and in the worse cases, both. The typical scenario is a surgeon trying to make a textbook picture perfect result and finding the patient’s tissues lacking, will take down their work to make it better, and repeat this process while the patient and everyone else in the room lingers.

Trying to avoid this, many surgeons will try to avoid any difficulties -the bad patch of scar tissue, irradiated body parts, areas of prior infection. But the mental contortions involved in avoiding “perfect” can result in actual physical contortions that in the end don’t pay off in good enough. I have not been immune to this, and I don’t think any physician or surgeon can honestly say they haven’t experienced some variation on this.

This patient is a younger middle aged man who in his youth experienced a posterior dislocation of his left knee, resulting in an arterial transection. This was repaired with an in-situ graft. Subsequently, he had complications of osteomyelitis and had his knee fused after resection of his joint. He did well with this bypass for several decades, but it finally failed several years ago, and a new one was created (image above).

Rather than directing the graft in line as in the previous one, this was was taken from a medial exposure of the femoral artery and tunneled superficially around the fused knee to coil lateral, ending in the anterior tibial artery.

This graft in turn thrombosed and was lysed by the outside surgeons and underwent serial interventions of proximal and distal stenoses at the anastomoses. The patient, when I met him, was contemplating an above knee amputation as a path to returning to work as a nurse in a rural hospital.

While there should be no reason long bypasses should do any less better than short bypasses, I do have to say these things about this patient’s bypass:

  1. No vein is perfect and the longer your bypass, the more chances you will have that a segment of bad vein will end up in your bypass
  2. Turning flow sharply can cause harsh turbulence. Turbulence can cause transition of potential energy into kinetic energy which acts to damage intimal, resulting in intimal hyperplasia.
  3. Thrombosis is a sure sign that your graft is disadvantaged, and the longer the period of thrombosis, the longer the intima “cooks” in the inflammatory response that accompanies thrombosis, making the vein graft even more vulnerable to subsequent intimal hyperplasia, thrombosis, or stricture.
  4. A high flow, small diameter vein graft entering a larger, disease free bed results in more turbulence but also Bernoulli effects that cause the graft to close intermittently, vibrating like one of those party favors that make a Bronx Cheer (a Heimlich valve). This is the cause I think of the distal long segment narrowing on this graft.

This patient was decided on amputation when our service was consulted, and after reviewing his CTA, I offered balloon angioplasty as his symptoms were primarily of paresthesia and neuropathic pain. I used cutting balloons and got angiographically satisfactory results.

intervention

The patient, although he admitted to feeling much better, was sad. He relayed that he had felt this way several times before, only to have his life interrupted by pain and weakness signaling a restenosis.

 

A direct graft would require about 10 centimeters of vein
 
It was only a month later when I heard the patient had returned with the same symptoms. He wasn’t angry nor full of any “I told you so” that frankly I was muttering to myself. Reviewing his CTA, he had restenosed to a pinhole. The vein, to use a scientific term, was “no good.”

The other interesting finding was that he had an abundance of very good vein. Following surgical dictum, his original and subsequent surgeons had used his vein from his contralateral saphenous vein. His right leg, fused at the knee, lacked a good calf muscle pump action. While there were no varicose veins, the greater and lesser saphenous veins were large and generous conduits, at least by 3DVR imagery, confirmed on duplex (image below, white arrows).

veins
3DVR showing presence of potential conduit

The extant arteries were smooth and plaque-free. I decided to harvest his lesser saphenous vein and through the same incision expose his distal superficial femoral artery and tibioperoneal trunk. While I anticipated some scarring, I was confident that the sections of artery I wanted to expose were easy to access because of some distance from the fused knee.

IMG_6478
On left short saphenous vein was harvested then same exposure used to expose TP Trunk

The picture shows the exposure and reversed vein graft in-situ, using the segment of lesser saphenous vein. As in prior experience in redo surgery, you can never know if a dissection will be easy or hard simply based on fear or concern for breaking something. It’s not until you start bushwacking –carving through scar and dealing with extraneous bleeding will you learn whether it was easy or hard. You can only be certain it was necessary. The only hitch was the femoral artery while well exposed, was buried in scar, and I chose not to get circumferential control as I was fairly deep, and had avid backbleeding from a posteriorly oriented collateral that required a mass clamp of the deep tissues.

Will this work better? Don’t know but it has a good chance, and I think a better chance. It is a large vein oriented in a straight path over a short distance going from good artery to good artery. This is better theoretically than a long meandering bypass with smaller vein. 

Categories
Commentary

VESS Meeting -Vail, CO 2015

IMG_3767

VESS is a special medical society whose mission is to foster academic activity and collegiality among young vascular surgeons. Dr. Vikram Kashyap, the outgoing president, gave an engaging talk about changing with the times, referencing three powerhouse rock groups -Rush, The Police, and the Red Hot Chili Peppers, three of my favorite groups.

Dr. Max Wohlauer presented our case report on “Osteosarcoma masquerading as an axillary artery pseudoanuerysm.”

IMG_3804

The case report ended the Friday morning session and was well received.

IMG_3805

Dr. John Weber opened the Friday afternoon session with “Median arcuate ligament syndrome is not a vascular disease.” Shown above prepping for the talk, he is also in the conference dress code of being ready for the slopes.

The talk was also well received and not surprising to most who agreed. In a conversation I had with Dr. Kenneth Cherry, he mentioned that he and Dr. Jeb Hallett had concluded as much decades ago.

The scuttlebutt in the conference was about the NY Times article about the scandalous overuse of femoral stents by some physicians. It is a matter of course that the first line of therapy for mild to moderate claudication is a combination of risk factor modification and exercise therapy -something not mentioned by the writers as something emphasized by Vascular Surgeons who as a rule are against plying stents on asymptomatic or mildly symptomatic patients.

The other thing was the tremendous demand for vascular surgeons, and the success of the 0-5 training programs which represent the future of vascular surgery. Dr. Karl Illig professed as much in the Q&A of a report from Wake Forest. Surprisingly the majority (100%) of 0-5 graduates in 2013 went into academic practice.

Categories
AAA Commentary techniques

The Parallel Bar -higher than you’d think

eye tiger big

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.

eyetiger1

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
AAA Commentary EVAR training

AAA Dynamism

 

September 11, 2008

This patient presented with abdominal pain and found to have a 9.5cm AAA. CT showed a previous stent graft that had slipped its moorings from a very short neck, and had actually flipped down on itself.

The patient was a very sick man with an AICD, end stage CHF, and severe COPD on home O2, and had been turned down for a heart transplant. He relayed that surgeon who had performed the EVAR 6 years before had informed him to follow up with his primary care physician.

This patient was repaired with an AUI-Fem-Fem with plug occlusion of his left iliac. The patient recovered and was POD #6, to his home.

 

November 13, 2014

This was not the first patient I had like this. Pictured below is another patient with a similar scenario from my personal photo bank. It is important to understand that aneurysms are dynamic, particularly if tortuous. Many of the early generation grafts were placed with great enthusiasm in all sorts of anatomy and they come back to us. Here at the clinic, Dr. Eric Turney and others reported that from 1999 to 2012, 100 patient required EVAR explant. Overall mortality was 17%, with an elective case mortality of 9.9%, non-elective mortality of 37%, and 56% mortality for ruptures (reference). Excluding the 13% of cases that were infected, progression of aneurysm disease was identified as the cause of late (>5yr) failure. It is a major source of open aortic experience for our trainees.

Illustrated below is the mechanism for loss of primary seal when there is a great deal of anterior bowing. Technically, anchoring mechanisms in modern grafts have worked to prevent or delay this effect, but it is something to consider in tortuous anatomy.

Reference: J Vasc Surg. 2014 Apr;59(4):886-93

Categories
Commentary

Chronicle of the scientific efforts and human costs at the outset

A great New Yorker article relays the efforts scientific efforts focused on Ebola and the calculus of ZMapp allocation.

Link