Arrow points to the esophagus. Tension is maintained by the tether on either side of the esophagus. By releasing one side, the tension is relieved.
The patient had been suffering with dysphagia for over a decade and had had extensive head and neck work up which found a goiter. Medical treatment of this goiter failed to relieve the lingering sensation of food getting stuck and the constant feelingof choking. It was only after a search for mediastinal sources of dysphagia that an aberrant right subclavian artery was found.
One of the advantages of working at the Clinics (I was a fellow at the Mayo, and currently on staff the the Cleveland) is that the infrequent is common while the common is rare. Recently in clinic, I had not one but two patients with dysphagia lusoria. It was the observation of Dan Clair’s, chairman emeritus, that by simply transposing the aberrant and yet nonaneurysmal right subclavian artery, the tension on the esophagus and trachea are relieved. Or as the dictum might go: it takes two hands to garrote someone.
The question is then what to do with the stump? The natural history of the untreated stump is unknown but may be more benign than one might assume. It certainly doesn’t degenerate into an aneurysm all the time -chest CT’s are fairly common and when these are discovered, they are not usually aneurysmal like persistent sciatic arteries which present typically as aneurysms with thromboembolism. Perhaps because we don’t sit on the subclavian artery as we would on a persistent sciatic artery that these aberrant right subclavian arteries don’t degenerate.
The old fashioned way I learned to treat these aneurysms (Kommerell Diverticula) was through a high thoracotomy and short graft repair of the aorta, replacing the origin of the diverticulum. This is a dangerous operation for an older, sicker, and often cachectic patient. The more recent reports involve a left carotid subclavian bypass or transposition and TEVAR after a right carotid subclavian revascularization. This second step may be unecessary if the non-aneurysmal stump proves to be benign. I don’t recommend coil embolization of the stump as mass effect of packed coils adjacent to the esophagus can cause dysphagia to recur, and this may necessitate an open resection and repair (observation, DC).
The patient underwent a successful right carotid subclavian transposition and had immediate relief of her dysphagia for the first time in over a decade, especially because she had been told she may have been imagining the discomfort. Kudos to her physicians who ordered the CT of the chest that discovered her arch anomaly. Follow up at 6 weeks showed a stable subclavian stump and patent transposition (images above). My plan is for regular interval CT’s with increasing intervals as time passes.
The basics of this air rocket pictured above is the projectile, attached by tube to a large bladder which when compressed by external force, ejects the projectile upwards. These are the same features of a popliteal venous aneurysm. First, the large chamber predisposes to stasis and thrombus formation. This thrombus will form on the flaccid walls which are areas where stasis occurs. During activity, it likely dislodge but catch at the outflow, obstructing it. Pressure builds up in the calf veins below, and flexing the knee and pressing the venous aneurysm ejects the thrombus towards the heart and lungs. Clot Gun.
The patient is a young woman who was an active college athlete. She had her first pulmonary embolism occur during practice several years prior to presentation. A duplex noted residual thrombus in her right popliteal vein. Over the next several years, she had two more episodes of pulmonary embolism whenever her anticoagulation was stopped. No thrombophilia was detected on workup. She was referred to the Clinic and Dr. Jerry Bartholomew in the Department of Cardiovascular Medicine noted in her records a mention of a dilated popliteal vein. On examination, she had no historical or physical examination findings to suggest a predisposition to pulmonary embolism. A duplex was ordered.
The duplex showed a 2.8cm popliteal venous aneurysm of the right leg. No acute DVT was seen but swirling rouleaux could be seen on the B-mode video. A CT venogram was ordered.
No other defect was detected. Operation was planned. Mapping showed no suitable superficial venous conduit, and venorrhaphy was planned. The patient was kept anticoagulated to the day of operation.
A curvilinear incision (lazy S) was made across the popliteal fossa and careful dissection revealed the aneurysm. It was soft and the vein was normal below in the calf. Above it, there was a tight fibrous band that was contricting it -a popliteal venous entrapment. I released this band. Using a 24 French Foley catheter inserted through a transverse venotomy on the popliteal vein below, the aneurysm was plicated to approximately 1cm diameter, and the catheter removed and the venotomy repaired.
The nerves were restored to their original position and the wound closed in layers. She recovered well and returned to followup about a month later. Duplex showed a patent vein and she had no symptoms of dyspnea.
The plan is to have her come off of her anticoagulation after a visit with Dr.Bartholomew. Reviewing the literature, my confreres at Mayo published their 15 year experience with popliteal venous aneurysms and found that 5 of their 8 patients presented with pulmonary embolism, and that most of their complications occurred with bypass repair while aneurysmorrhaphy fared well (reference). Because of their rarity, about 200 cases in the literature, it may be assumed that many are not found until complications occur or never found because pulmonary embolism, the most common complication, results in death. Also, it would be easy for unknowing physicians to assume that popliteal venous aneurysm falls under the umbrella of varicose vein which this is not. They should be treated when found, and in most cases, such as this, venorrhaphy is preferred.
Reference
Johnstone JK et al. Surgical treatment of popliteal venous aneurysms. Ann Vasc Surg 2015;29:1084-1089.
The proximal anastomosis is the most critical portion of an open aortic aneurysm repair. Several concepts are central to creating an anastomosis that doesn’t bleed at unclamping: managing narrow spaces, overcoming distortion, and using just enough tackle.
Narrow Spaces
The transabdominal exposure is a narrow space. The work is done under the overhanging left renal vein, the transverse colonic mesentery, the liver, the rib cage. Extra lateral space can be made by eviscerating the bowel, but at the cost of higher rates of ileus, and doesn’t solve the first problem. The standard DeBakey aortic clamp and straight Fogarty clamps stand nearly straight up, limiting the space above the incision at the aortic neck. My goto clamp is the Cherry Supra Celiac Aortic Clamp, designed by my mentor Ken Cherry.
It hugs the contour of the mesentery and liver overhang, and the handles stay out of the way above the wound. It will also tilt up the aorta because of the weight balance. The other option is to apply a transverse clamp, which I will discuss in a later post. The transverse clamp leaves the suprarenal space free of clamp, but can be difficult if not hazardous to apply. The clamp has to be hemostatic and this can be challenging with atherosclerotic plaque -preoperative planning must include planning for safe clamp sites. A suprarenal clamp may be limited by the presence of the terminal insertions of the diaphragmatic crurae. I have recently found that dividing these crurae with a Maryland tipped Ligasure, a laparoscopic instrument I use to dissect the retroperitoneum, makes short order of what can sometimes be an awkward exposure in this tight space. Finally, endarterectomy of the neck should be done carefully to let needles pass without difficulty.
Distortion
The proximal anastomosis is ideally just another end to end anastomosis -attaching a circle to a circle, but clamping narrows and distorts the circular aortic neck (top illustration). To envision this, imagine the aortic neck being a clock face:
Lets say the suture should be applied at each of the hours and half hours. You get ready to sew your first aortic neck and after endarterectomizing some plaque, you get this:
The important point is that you still have to apply the original plan of applying sutures evenly and at an appropriate frequency (about 3mm apart), to avoid gathers and gaps, especially on the posterior wall. One way is to apply outward tension with a Wheatlander retractor in the aortic sac.
The posterior wall of the aorta should be distracted to avoid distortions that create uneven gaps between passes of the needle. The bites on the aorta should be generous, on the graft, less so. As long as the gaps between the sutures is the same on both aorta and graft, you shouldn’t get leaks. The other principle to guide you is the needles should pass pointing to the center of the clock -this is challenging in the Dali clock, but if you pivot your shoulder, your suturing won’t be bullied by the distortions and the narrow space.
The Right Tackle
You don’t go after panfish with a deep sea tackle. Pictured below are a spinning lure for trolling with a large hook and a small dry fly with narrow guage hook for comparison.
Which hook creates the larger hole in the fish’s mouth? In fact, both lures can be used to catch the same large trout, but in different situations.
On a lake, large hook, on a stream, small hook for same fish.One of the techniques which I have borrowed from our partners in cardiac surgery here at the clinic is using smaller guage monofilament and needles. I once co-scrubbed an aortic arch case with Eric Roselli, and was bemused to see him sew graft to the fearsome ascending aorta with 5-0 monofilament suture. Then I saw no needle hole bleeding and was sold. Up to then, I had switched from my 3-0 on SH needles to 2-0 on MH needles -basically the largest vascular needle, and saw posterior aortic wall break down from the needle trauma. Unfortunately, 5-0 suture doesn’t come long enough, the CV needles aren’t big enough to sew posterior wall. I now use 4-0 on SH with 48cm length suture. Ideally, we’d have a 5-0 monofilament on a 60cm suture with a SH shaped and sized needle with the narrow guage of the CV needle.
Also, because the needles are finer and I favor supersized Castro needle holders. The needle holes which represent rents in the aortic wall are far easier to deal with using a smaller needle. Right tackle.
Being a homeowner, you are sometimes stuck negotiating a repair with various workmen whose knowledge of building esoterica is only exceeded by their subliminal contempt of a man who can’t rip out flooring and drywall to renovate a kitchen or bathroom. I can only hope that I don’t come off that way when discussing human plumbing. It was a year into my ownership of my current home that I noticed that many of the drains in the window wells were clogged. A very unpleasant afternoon was spent digging out soil and leaves while trying to snake a coat hanger (access wire), and when I gave up, I tried to call a plumber. Only it was the wrong specialist. “You want a sewer guy.”
The sewer gentleman was a meticulously groomed Italian immigrant who walked about the house after inspecting the drain in question. After some harumphing, he declared he needed to do some tests which included running dye through the various downspouts around the house and drains in the house. Contrast drainography! To top it off, he wanted to run a camera on a flexible tube through to check out the drains. Endoscopy! Plumbing, he sniffed, was easy, but drains were an art.
For the record, our basement was dry, but I could see the money meter whirring away. It was only a few weeks removed from a spring storm where several homes a few blocks away had catastrophic flooding when rains overwhelmed the capacity of their drainage –Drainage Insufficiency!
The testing was fine, but he ended up recommending resealing the entire East side of the house and rebuilding the window wells, because while the house was dry, it was compensating by rerouting a lot of drainage down gutters and the downsloping lawn to the street –Collaterals! and he couldn’t promise the house wouldn’t flood with a torrential month of rain which Shaker Heights is prone to being downwind of the Lake.
And it is with this wisdom that I see the increasing numbers of chronic venous occlusions. For example, the patient whose venogram is pictured above initially complained to her obstetrician of persistent heaviness in the pelvis and swelling of the legs after delivering a healthy baby. MRV showed abundant pelvic collateral veins and she was referred to me.
Our first test in our clinic is a venous duplex of both legs and the abdominal veins. There was an occlusion of the inferior vena cava below the renal veins extending the the iliac veins bilaterally. I am about to give a talk on this and I composited the ultrasound.
She had iliocaval occlusion, chronic. Her symptoms were over two years, and were ever worsening. She hadn’t developed permanent skin changes of chronic venous insufficiency, but probably would in a decade or sooner. I recommended venography and an attempt at recanalization.
The procedure went well, and her symptoms abated. For my trainees, the absence of collaterals in the after image is the sign that hemodynamically, the revascularization is the preferred route of egress. Surprisingly, this has stayed open over two years, but again, my exceedingly well paid sewer gentleman consultant, had something to say about it.
Drainage, he declared, was different from plumbing, because things move slower and there is usually solid matter -poop, leaves, dead birds, etc., to contend with. Larger, high volume drains do best with a direct in-line connection with the city sewer, while downspouts and window wells with their twists and turns and only occasional flushings clog up too well. Wise words.
It gave me a reason why iliocaval venous interventions did so much better than femoropopliteal ones.
Venous interventions connect confluences to the main drain, in most cases the suprarenal inferior vena cava. The iliocaval segment drains the common femoral confluence, which even in the worst of chronic lower extremity DVT’s, seems to reopen with several months of anticoagulation. Not the same for the popliteal confluence which, getting much less blood flow to drain, and having a smaller diameter, stents in the femoropopliteal veins just don’t do as well. Plus, it has to drain against a greater hydrostatic pressure. The drain guy’s wisdom seems to apply. It also has implications for the kind of stents we place, and the kinds that are being developed specifically for the venous side.
The innovation of sabremetrics in baseball management and finance as described in Michael Lewis’ wonderful book Moneyball wasn’t just the ability to quantify skill to predict outcomes, it was the ability to assemble that skill without overpaying. For a baseball team on a budget, spending all your payroll on a superstar makes no sense when you can get equivalent quants of skill in a statistical aggregate of no-name players with proven metrics. Rather than pay for an A-Rod, you can recruit, and pay for, 5 players that in aggregate, statistically achieve what you would get with a healthy A-Rod, so the thinking goes. How does this translate into vascular surgery? Can we arbitrage complication rates?
The open repair of type II thoracoabdominal aortic aneurysms is a heroic endeavor, putatively best done by surgeons wearing cowboy boots, and classically comes with sobering complication rates that exceed 20% for death and paralysis. Is it possible to reduce this risk by subdividing this most enormous of cardiovascular operations into component parts?
The patient is a middle aged man in his 50’s who presented with a type B aortic dissection. His dissection flap spanned from his left subclavian artery to the infrarenal aorta. He was a long time smoker and had hypertension that was difficult to control, made much worse after his dissection. He had a moderate dilatation of his thoracic aorta, maximally 36mm and tapering to 35mm in visceral segment. There was a 4.9cm infrarenal AAA where the dissection terminated.
His chest pain resolved with blood pressure control and he was discharged, but in followup his thoracic aortic segment grew and his blood pressure worsened, never getting below a 150mmHg systolic despite multiple agents. CTA two months after presentation, showed growth of his TAA to 44mm from 36mm in two months and the visceral segment showed that his dissection flap impinged on flow to the right renal artery. His AAA remained the same. He continued to have bouts of chest pain related to hypertension.
Twenty years ago, the board answer would have been to replace the whole aorta. In young, otherwise healthy man who had been working in road construction up to the dissection, he would have been considered a candidate for a direct open repair of the type II thoracoabdominal aortic aneurysm. From the landmark paper out of Houston by Dr. Svensson in 1993, open type II TAAA repair was associated with about a 10% death rate and 30 percent paralysis rate. Waiting a few months for the aneurysms to grow further in this patient, in the 90’s this patient would probably have ended up with an open TAAA repair. Good thing we have better options.
The goals of modern therapy are to treat the urgent indication while holding off repair of less critical segments of the aorta, and to do so in a way that each operation builds on the previous one.
This patient needed a left subclavian artery debranching and then TEVAR of his dissecting thoracic aortic aneurysm, and intervention on his right renal artery. We did this in one setting performing first a left carotid subclavian artery transposition and then percutaneous TEVAR from the left common carotid artery origin to the supraceliac abdominal aorta.
The completion aortography showed good deployment of the CTAG device from the left common carotid artery origin to the celiac axis origin. The false lumen was no longer visualized. The right renal artery which was narrowed was treated with a balloon expandable stent.
The distal thoracic aorta, the true lumen was constrained by a chronic dissection flap. It is here I gently dilate the distal thoracic stent graft with the hopes of eliminating the distal false lumen. This is different from the acute dissection where I rarely balloon.
The TEVAR was done percutaneously, minimizing the overall time in the operating room. The technical details of the transposition can be found in the excellent paper by Dr. Mark Morasch.
When I do this procedure for acute dissection, I quote the patient a general risk of stroke, paralysis of about 2-5% and death of 1-2 percent for someone with low cardiopulmonary risk like this patient had. He recovered rapidly and went home post op day 5.
Followup post TEVAR
He at 6 month post TEVAR followup, CTA showed stablility in his thoracic aorta. in infrarenal AAA grew from 5.0 to 5.7cm between the 1 month CT and the 6 month CT.
The terminus of the stent graft excluded the false lumen in the thoracic aorta but also resulted in filling and pressurization of the false lumen beyond and can be seen as a 44mm lateral dilation of the visceral segment of the aorta which had developed in the 6 month interval since the TEVAR.
The infrarenal neck continued the dissection and had dilated to about 36mm, but was parallel for a good length above the AAA. I decided to treat the inrarenal aorta with direct transabdominal repair. This would allow me to fenestrate the aorta, and possibly prevent further growth of the viseral segment while reserving the retroperitoneum for the visceral segment repair if it came to it. The neck diameter was 36mm.
His operation was performed via an anterior approach with the patient supine. A tube graft repair was performed expeditiously and included resecting the dissection flap up to the clamp. Care was taken to avoid injury to the renal stent. The proximal anastomosis went well – the dilated aorta yet had strong tissue strength. A felt strip was used to buttress the aortic side of the anastomosis. The estimated risk of paralysis was less than 1% and risk of death was less than 2%. The patient recovered uneventfully and went home on POD 5.
He did well in subsequent followup, having successfully quit smoking. He retired early on disability and was becoming more active, but the visceral segment dilatation was concerning. At 6 months post infrarenal AAA repair, he underwent CTA and it showed patent thoracic stent graft and infrarenal abdominal graft. The intervening visceral segment continued to enlarge and was now 46mm. The decision was to wait another interval 9 months to see if this would stabilize. The segment grew some more and was 49mm. He wanted to give it another 6 months and at that time, CTA showed further growth over 5cm, and he had developed some abdominal discomfort. He was taken to the operating room.
A four branch repair of the visceral segment thoracoabdominal aortic aneurysm was performed. The diaphragm was taken down and the stent graft was clamped as was the infrarenal tube graft. A premade Coselli graft was used to bypass to the right renal, SMA, celiac, and left renal in those order. The patient had a CSF drain for the case which was removed on postoperative day 2. He recovered rapidly and went home on postoperative day 6. His estimated risk of paralysis was about 2-5%, mitigated by a protocol centered on CSF drainage and blood pressure control. His risk of death was 5%. Telephone followup reveals the he is pain free at a month out and functional nearly at baseline.
This illustrates the notion that three smaller operations in an aggregate over three years achieved the equivalent of the single big open type II TAAA repair.
Illustration on left from Svensson et al.
The idea is to make each step achievable -like coming down a mountain taking three days on well marked paths rather than base jumping off the summit.
Clearly, the patient was younger and a fast healer, and credit must also be given to the anesthesia/critical care team who see high acuity cases in volume every day and not every patient can expect to have such short stays and excellent outcome, but these are far more likely if operations are planned out in such a manner.
Dr. Mohammed Abbasi – joi150040 -Effect of a Retrievable Inferior Vena Cava Filter Plus Anticoagulation vs Anticoagulation Alone on Risk of Recurrent Pulmonary Embolism A Randomized Clinical Trial. JAMA 2015;313:1627-1635.
Dr. Keith Glover –PIIS1078588413005947 -Percutaneous Manual Aspiration Thrombectomy Followed by Stenting for Iliac Vein Compression Syndrome with Secondary Acute Isolated Iliofemoral Deep Vein Thrombosis: A Prospective Study of Single-session Endovascular Protocol. Eur J Vasc Endovasc Surg 2014;47:68-74.
His operation was performed via an anterior approach with the patient supine. A tube graft repair was performed expeditiously and included resecting the dissection flap up to the clamp. Care was taken to avoid injury to the renal stent. The proximal anastomosis went well – the dilated aorta yet had strong tissue strength. A felt strip was used to buttress the aortic side of the anastomosis. The estimated risk of paralysis was less than 1% and risk of death was less than 2%. The patient recovered uneventfully and went home on POD 5.
A Surgeon's Notes 