Exovascularist’s Dilemma: Where Is Our LIMA to LAD

During our daily morning huddles, peopled by cardiologists and cardiac surgeons, one thing impresses me more than anything else. The assembled interventional cardiologists, world class and renown, they who can place a stent in any part of the body, will defer to the unassailable superiority of the LIMA to LAD bypass over any existing intervention. I am always a little sad that the analog for this, the vein bypass in the leg does not get the same love. The open surgical bypass of the leg is the great straw man at international symposia. It is fast becoming a diminishing and curious habit of a fading generation.

The acknowledged superior hemodynamics and patency of the bypass is diminished in the literature by pooling patency loss with other factors such as amputation, heart attacks, and death. Some vascular surgeons dogmatically cling to habits learned in training that favor complications, making themselves their own worst enemies both in the literature and in the marketplace. These bad habits involve long incision length, closure techniques that do not anticipate edema, and wound orientation that makes failure more likely.

Operations require far more support and resources to succeed than do interventions that soon go home. Brilliant operations alone will not heal the patient. It is pathways and postoperative care infrastructure and staff that prevent these secondary complications -the very complications that keep the leg vein bypass from being as respected, if not loved, as the LIMA to LAD.

The postoperative care of these patients devolves to management of leg edema. No medical or nursing school adequately teaches the basic science nor management of edema, which is the most common vascular condition

The incisions are too long in the classic vein bypass. When you create and then close an incision, the inflammation drives the accumulation of fluid in the extracellular space – creating edema. This postoperative edema, poorly managed, results in complications that leave the patient hobbled with time lost to healing wound complications, pain, and excess limb weight. Additionally, vein bypasses usually involve groin exposure and the delicate lymphatics that coalesce there are perturbed or destroyed during exposure. Postop, this damage and the inflammation rapidly overcomes the capacity of a lymphatic system. The traditional vein harvest also involves cutting through deep layers of fat. The fat is typically closed by broad sutures that create areas of fat necrosis -potential fodder for bacteria. The best ways the complications of long and deep incisions is to avoid them altogether. The calculus of the operative moment – “I must see the vein,” must include the vision of a patient losing months to wound therapies to heal a gaping, necrotic, infected wound. I recommend skip incisions or adopting in-situ bypass technique with endovascular management of fistulae. Or corral your cardiac PA to harvest the vein segment in the thigh after mobilizing the vein in the leg with the endoscope.

The incisions are often closed with Nylon sutures and skin clips which can become potential foci of infection. With edema, they create zones of ischemia around them, killing skin and creating entry points for skin flora as the skin expands under an unyielding clip or suture. Placed under a pannus, these sutures or clips fester in an anaerobic environment. Closure should adhere to anatomy. The body relies on connective tissue planes to keep itself together. In the groin, these are Scarpa’s layer and the dermis. They should be closed with absorbable monofilament in a buried interrupted fashion at the dermis with a final running subcuticular layer of 4-0 absorbable monofilament. Steristrips or glue at the skin finishes the job. If you use sutures, particularly at the distal anastomotic site, take care to realize that you have about 12 hours before the skin dies in the best of circumstances, and less with microangiopathy of diabetes and ESRD. Squeezing out the edema before closure with a sterile Esmarch or short counterincisions or even a large one to allow for tension free closure over an anastomosis will prevent wound complications over your graft.

The classic longitudinal groin incisions that cut across the inguinal crease divides a tension point -that crease is like a cord that supports the pannus that is slung over it and when divided and then closed with a stitch, that stitch then bears the weight of that pannus every time the patient sits up or stands. If you are observant, wound necrosis typically starts at the groin crease under a surgical clip or suture. Incisions in the groin should be obqlique and parallel to this crease, or if you can, even inside this crease. When these wounds are closed, the natural lines of tension are in line with the incision rather than orthogonal to it. The natural forces keep the wound shut.

This is only the first step. The next is keeping the wound clean and dry for at least 5 days. At the Mayo Clinic, where I trained, the nurses up on 5 Mary Brigh were trained to blow dry the groin wounds every few hours on cool setting and redressing the wound with dry gauze. You can get something close to it by ensuring the wounds painted with betadine, allowed to air dry, and dressed with dry gauze. If there is a constant leak of fluid, you have a serious problem as there is too much edema in the leg, or the wound isn’t closed, or there is a lymph leak. It needs to be actively dried out or you get a wet, macerated, infected wound like a grenade went off in the groin.

They don’t teach compression wrap techniques in medical or nursing school

The simplest thing to avoid lymph leaks is to not make them. Cutting near lymph nodes is hazardous, and once below Scarpa’s you have to orient your dissection directly over the femoral artery. Stray horizontally and you will undoubtedly cut one of the 4 to 10 invisible lymph channels.

They are invisible but detectable -after you break them, you will see a constant wetness in the wound. Think about injecting a cc or two of Lymphazurin (Isosulfan Blue, for those not allergic to Sulfa) into the intertriginous space on the same foot and you will see the lymph channel in bright blue, or stare carefully at the likely spots for a lymph leak and clip it, burn it, Ligasure or Harmonic scalpel it.

Lymph leak identified from saphenectomy incision (for CABG)

So how did we get to a rather dry discussion about edema? Wound complications are tremendously debilitating and offset any benefit from vein bypass operations. These long incisions become terrible big wounds if not prevented. It takes the concerted effort of a team and particularly nursing in actively managing edema. And at the end, the patient too must be included in this discussion. For the vein bypass of the leg to get the same respect and love as the LIMA to LAD bypass, surgical wound complications must become never events.

Water goes downhill

Arterial Restoration -Something New, Something Old

Something that I recently promised Dr. James S.T. Yao, I will be working to publish on my stent removal and extended remote endarterectomy cases and techniques. Meanwhile, here is a talk.

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

CXR.jpeg
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.

prestent angiography.png

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.

post deployment angiography.png

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.

7 months post op.png

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.

Salvage: A different approach to graft infections in the groin

The principles of salvage are in rescuing valuable undamaged goods in the setting of catastrophe. This guided me when a patient was flown in from an outside institution to our ICU with a saline soaked OR towel in his right groin -he had had an aorto-bifemoral bypass for aorto-iliac occlusive disease a year prior, but had never properly healed his right groin wound which continued to drain despite VAC therapy and wound care. On revealing his groin, this is what I saw:

EndoRE in graft infection.002

A CT scan was sent with the patient but has been lost to time, and it showed a patent aorto-bifemoral bypass send flow around an occluded distal aorta and iliac arteries. The graft did not have a telltale haze around it nor a dark halo of fluid which signaled to me that it was likely well incorporated and only sick in the exposed part. The patient was not septic, but had grown MRSA from the wound which was granulating from the extensive wound care that had been delivered.

EndoRE in graft infection.009

I felt that it would be possible to move his anastomosis point more proximally on the external iliac in a sterile field (figure above), and then close, then endarterectomize the occluded external iliac artery after removing the distal graft, then after vein patching, cover the repair with a sartorius muscle flap. It would salvage the remaining graft and avoid a much larger, more intense operation which was plan B. To prepare for that, I had his deep femoral veins mapped.

The patient was prepped and draped, the groin was excluded by placing a lap pad soaked in peroxide/betadine/saline solution (recipe for “brown bubbly” liter saline, a bottle of peroxide, a bottle of betadine), and covering with an adesive drape. The rest of the abdomen was then draped with a second large adhesive drape. A retroperitoneal (transplant-type) right lower quadrant incision was made (below) and the external iliac artery and graft were exposed. As predicted on CT, the graft was well incorporated.

EndoRE in graft infection.003

The external iliac artery was opened and focally endarterectomized of occlusive plaque (image below). The adventitia had good quality despite the longstanding occlusion.

EndoRE in graft infection.004

The graft was mobilized and transected and anastomosed end to side to this segment of artery (below). Dissecting was made difficult by how well incorporated it was.

EndoRE in graft infection.005.jpeg

The wound was irrigated (with brown bubbly) and closed, dressed, and sealed over with the adhesive drape. The groin wound was then revealed and the graft pulled out (below).

EndoRE in graft infection.006

Remote endarterectomy using a Vollmer ring was used -in this case I didn’t use fluoroscopy given the short distance to the terminus of the plaque which i had mobilized in the pelvis.

EndoRE in graft infection.007

The plaque came out easily and was not infected appearing. It is shown below ex vivo.

EndoRE in graft infection.008

A segment of saphenous vein was harvested from the patient medially and the arteriotomy was patched. The sartorius muscle was mobilized and applied as a flap over this. The wound was irrigated with brown bubbly and packed open with the intention of VAC application.

The patient healed very rapidly and remains infection free. I had used this approach on several occasions in the past and twice more recently. It truly is salvage as it preserves the uninfected graft while never exposing it to the infection in the process of operating. It avoids having to remove the whole graft which then damages the left side -I have seen other surgeons take this approach elsewhere taking a all-or-nothing approach to graft infection to considerable morbidity to the patient. It avoids having to harvest deep femoral vein -another large operation to which the body responds truculently. The patient recently came by for his 4 year followup, still smoking, but legs preserved.

Followup At 4 Years

IMG_0657

The patient came back in followup -it has been 4 years since his infection was repaired. He was complaining of short distance claudication. His wound healed well and remains closed. CTA shows along with his short segment SFA occlusion which we will treat, a widely patent R. EIA (below).

CTA 4 year followup

The remote endarterectomy of the external iliac artery remains patent. Compare this to the preop CTA which I found and wasn’t available when I posted this case originally:

 

preop CTA_4

The chronically occluded EIA can be readily seen. The artery shown in the current CTA is that recanalized artery.

 

Reversing paralysis with a bypass

Dissection CTA

The patient is middle aged and had a type B thoracic aortic dissection (TBAD) as a consequence of recreational substances that acutely raised his blood pressure. At the outside hospital, he had a CTA showing the dissection extending from his left subclavian artery and causing occlusion of his superior mesenteric artery (SMA). He developed abdominal pain and was swiftly transported to our acute aortic syndrome unit. He was taken to the operating room and underwent a TEVAR of the dissection and stenting of his SMA -this is similar to other cases I have discussed in prior posts so I am omitting the technical details. The stent covered the left subclavian artery origin to exclude the origin of the dissection. The stent was extended to the distal thoracic aorta but did not go to the celiac origin. 

TBAD post stent

Post procedure, his lactate never rose and he was maintained on the usual post procedure protocol of keeping MAP’s (mean arterial pressure) above 80mmHg. His left subclavian artery was covered but I do not routinely bypass, especially when the left vertebral artery is at least equal in size to the contralateral one. I don’t often place spinal drains for urgent/emergent cases particularly in patients who have never had infrarenal aortic surgery and patent hypogastric arteries. He was kept sedated overnight and awoke in the morning unable to move his legs to command. He had no pain sensation up to his umbilicus.

A spinal drain was emergently placed and his blood pressure was raised to MAPs of 90+, but these failed to reverse his paralysis. After discussion among my world class partners, I chose to take the patient back for a carotid subclavian bypass which was done through a single incision with a dacron bypass graft.

Carotid subclavian bypass CTA

His paralysis resolved. He was discharged home, ambulating without assistance. Spinal cord complications are reported to occur between 1-5 percent of patients undergoing TEVAR for complicated TBAD. They were seen in 2 of 72 patients in the TEVAR arm of the INSTEAD trial (Circulation, 2009 vol. 120(25) pp. 2519-28), and was permanent in 1. While there are some who routinely place prophylactic drains, it is unclear to me that they have a significant effect if placed unselectively. I will place a Preop drain in the instance of infra renal graft, hypogastric arterial occlusive disease. In the instance of a dominant left vertebral, I will perform concomitant bypass, but just as often not. This is a gratifying and rare outcome of paralysis reversed with a carotid subclavian bypass when spinal drain and permissive hypertension did not.