Complex Aortic Intervention

By Jason S. Carlson, RT, and Bruce H. Gray, DO
 

CASE PRESENTATION
A 66-year-old, white woman presented with a chief complaint of bilateral lower-extremity pain and numbness exacerbated by ambulation. For the previous year, however, she could walk several blocks before the onset of thigh and calf pain. Recently, her ambulatory distance decreased to 50 feet. Her medical comorbidities included COPD, coronary artery disease, and renal insufficiency (serum creatinine, 2.0 mg/dL). Femoral, popliteal, and pedal pulses were not palpable; only Doppler signals were present. There were no ischemic ulcerations or fissures, no evidence of atheroemboli, and no muscle wasting. Decreased sensation typical of diabetic neuropathy was evident in both feet. Her initial work up considered neurogenic and vascular causes for her leg pain.

LABORATORY DATA
An MRI revealed some degenerative changes without nerve impingement. The abdominal aorta was calcified and had abnormal signal intensity. An abdominal ultrasound revealed a small aorta (1.5 X 1.3 cm). The patient’s ankle/brachial indexes (ABI) were 27 (right) and 32 (left). These studies suggested severe aortic disease and diagnostic arteriography of the aorta and lower extremities was performed.

ANGIOGRAPHIC FINDINGS
The diagnostic arteriogram was obtained from a left brachial approach and showed an occlusion of the infrarenal aorta immediately inferior to the renal arteries to the level of the inferior mesenteric artery (IMA) (Figure 1). The celiac and superior mesenteric arteries (SMA) were widely patent, with the SMA filling the IMA. The IMA then filled the distal aorta and lower extremities. Both the common, internal, and external iliac arteries were quite small but patent, along with the common, profunda, and superficial femoral arteries.

HOW WOULD YOU PROCEED?
1. Attempt to treat medically to relieve increasing symptoms?

2. Perform an endovascular procedure such as percutaneous transluminal angioplasty (PTA) with stenting, thrombolysis, and/or thrombectomy?

3. Perform an anatomic (ABI, aortobifemoral) or extra-anatomic bypass (axillofemorofemoral)?

COURSE OF ACTION
The endovascular treatment option was pursued because of the patient’s significant medical comorbidities and disabling claudication. Prior to the procedure, the patient was admitted for overnight hydration, which lowered her creatinine from 2.0 to 1.6 mg/dL. Conscious sedation was initiated and the patient was placed in the supine position. A Doppler Smart needle (Escalon Vascular Access, New Berlin, WI) was used to cannulate the common femoral artery (CFA) and a 5-F sheath (Terumo Medical Corporation, distributed by Boston Scientific, Natick, MA) was introduced. A .035-inch Wholey wire (Mallinckrodt, Hazelwood, MO) was utilized initially to traverse the aortic occlusion. Because the Wholey wire can traverse “new” clot well and “old” clot poorly, this maneuver discriminates “old” versus “new” occlusions. After several failed attempts, it was apparent that the occlusion was older than anticipated based on the history. A combination of a 5-F, angled, Glide catheter (Terumo Medical Corporation) and a .035-inch Glidewire (Terumo Medical Corporation) was used, and the wire and catheter reached the descending thoracic aorta. Although the final catheter position was luminal, the transversal of the aortic occlusion was thought to be subintimal. Intravascular ultrasound (IVUS) was used to evaluate the arterial plane of the wire. An 8.2-F, 12-MHz IVUS catheter (JOMED, Inc., Beringen, Switzerland) was delivered through an up-sized 8-F sheath. The IVUS clearly identified the subintimal plane, which was found to re-enter the true lumen below the level of the SMA. This raised concern of jeopardizing the patient’s mesenteric circulation.

The 8-F sheath that was placed in the CFA totally consumed the lumen, causing ischemic pain of the right leg. The sheath was decannulated while maintaining wire access, and mild hand pressure on the groin to maintain hemostasis relieved the ischemia temporarily. This maneuver had to be completed twice during the procedure.

The left arm was prepared and draped, and a 5-F sheath was placed into the brachial artery. A 5-F, multipurpose catheter was placed into the abdominal aorta. A Glidewire was then used through the multipurpose catheter to traverse the aortic occlusion, and a 25-mm Microvena snare (Microvena, Minneapolis, MN) was used distally to externalize the wire through the right groin sheath. The IVUS catheter was placed over the wire via the groin sheath to verify true luminal position. Once the IVUS catheter was in the descending thoracic aorta, a Wholey wire was exchanged for the Glidewire. This provided better support for angioplasty and stenting.

A 6-mm x 4-mm Opta-Pro balloon (Cordis Corporation, a Johnson & Johnson company, Miami, FL) was used to dilate the occlusion followed by an 8-mm x 4-mm Opta-Pro balloon. Intra-arterial pressures were measured and the initial 100-mm gradient was reduced to 50 mm after dilation. A 59-mm Genesis (5910) stent (Cordis) was deployed using an 8-mm x 6-cm Marshall balloon (Medi-Tech) just below the level of the left renal artery. An additional 29-mm Genesis (2910) stent was used to extend just proximal to the aortic bifurcation. A 10-mm balloon was used to post-dilate the aortic stents. This resolved the pressure gradient across the aorta. The aorta appeared healthy from an angiographic standpoint (Figure 2), but a dissection hindered flow down the left common and external iliac artery. The dissection was caused by the initial subintimal aortic traversal.

An 8-mm x 20-mm Smart stent (Cordis) was placed at the origin of the left common iliac. This did not fully resolve the dissection, and a 7-mm x 40-mm Smart stent was deployed in the proximal left external iliac artery. The completion arteriogram showed brisk flow through both renal arteries without compromise or emboli, the SMA reconstituted the IMA, and the aorta showed 20% residual stenosis, with both internal and external iliac arteries filling via antegrade fashion (Figure 3). A total of 340 mL of nonionic contrast material was used with a minimal amount of blood loss. An 8-F Perclose (Abbott Laboratories, Inc., Abbott Park, IL) device was used to close the right femoral artery while manual pressure was applied to the left brachial site.

The patient was stable from a cardiovascular perspective and had palpable femoral, popliteal, dorsalis pedis, and posterior pulses at the conclusion of the procedure. There was no clinical evidence of atheroemboli. The patient was discharged from the hospital the next day with an ABI of 0.9, bilaterally. Her serum creatinine was stable at 1.6 mg/dL, and she had good urine volume.

OUTPATIENT FOLLOW-UP

The patient reported shortness of breath, sluggishness, and a general feeling of being unwell at her 2-week follow-up visit. Her blood pressure registered 94/56 on the right and 84/54 on the left. We did not change her medication regimen, which included clopidogrel 75 mg q.d., celecoxib 200 mg q.d., metoprolol 200 mg q.d., losartan and hydrochlorothiazide 100/25 mg q.d., hydrocodone and ibuprofen q.i.d. p.r.n, and a albuterol and ipratropium inhaler. We discontinued losartan, and cut the metoprolol dose in half at 2-week follow up. At 6 weeks, the patient’s overall sense of well-being had improved. Her ambulatory status included all activities of daily living without claudication. Her pulmonary status was stable. Her blood pressure was stable on less medication. At 6 months, her ABIs were 1.0 bilaterally, and she had a continued sense of well-being. Her lifestyle changed because of the ability to do her own grocery shopping, attend church, and participate in other social activities.

CASE DISCUSSION
This case proved to be complex, with numerous procedural modifications to a simple balloon angioplasty and stenting. Some of the more instructional aspects of the case were:

1) The initial diagnostic arteriogram was obtained from the left brachial approach. This allowed full arteriographic evaluation without disturbing the pathologic findings. A treatment plan could then be devised.

2) The decision for endovascular intervention instead of an open surgical bypass, which is the more common choice, was based the patient’s extensive list of comorbidities, including COPD with supplemental home oxygen, coronary artery disease, renal insufficiency, and diabetes. The selection of the most appropriate procedure must be based on the clinical scenario, not solely on angiographic or economic factors.1-6

3) The clinical history (recent worsening of stable claudication) suggested that the aortic lesion was probably a stenosis that had recently thrombosed. Suspecting the occlusion to be recently formed, traversal of the lesion was assumed to be easy. The Wholey wire usually crosses acute or subacute thrombus (luminally) easily compared to chronic thrombus and plaque. This occlusion ?felt? more chronic; consequently a Glidewire was chosen. The Glidewire crosses just about any occlusion, but not necessarily in the true lumen. The shape of the wire (while traversing the lesion) can usually distinguish a luminal from a subintimal traversal. A large circuitous bend or right angle turn that is larger than the expected lumen of the vessel is characteristic of the subintimal plane. A straight wire or small J-loop to the front of the wire is more characteristic of a luminal traversal. A luminal traversal was suspected with the initial wire traversal and was evaluated with IVUS, which confirmed the wire was subintimal. Likewise, once the occlusion was crossed from the brachial approach, the luminal traversal plane was confirmed with IVUS. The outcome could have been compromised had balloon angioplasty been attempted with the wire in the subintimal position (particularly because it re-entered just below the SMA). This could have compromised not only the mesenteric circulation, but also the renal arteries. Vessel rupture is more common with subintimal angioplasty. Acute rupture of the aorta in this particular patient would most certainly have been fatal.

4) The 12-MHz (rather than 20-MHz to 30-MHz) catheter images the aorta well, however, it required an 8-F sheath. Because of the small CFA in this patient, the sheath totally consumed the CFA lumen. The patient reported right leg pain. Ischemic pain can be caused by flow obstruction from the sheath with or without concomitant thrombus. By decannulating the sheath over the guide wire, reperfusion of the limb quickly relieves the pain without losing arterial access. Heparin was administered to increase the activated clotting time to longer than 300 seconds to minimize the risk of perisheath thrombus formation. It was necessary to decannulate the sheath several times during the procedure to ?give the leg a drink.?

5) Isolated lesions of the infrarenal aorta are unusual. Arteriosclerosis involving the aorta and common iliac arteries is more common. The kissing balloon technique described by Tegtmeyer for aortic bifurcation disease can at times be used to treat isolated aortic disease.3 This is important to consider when the plaque involves the distal portion of the aorta and the tail of the balloon must be in the common iliac artery. Using two smaller balloons that fit the diameter of the common iliac arteries is safer rather than one large aortic-sized balloon at the aortic bifurcation.

6) A balloon-expandable stent was selected for the aorta because the deployment is more accurate and the radial force is superior to self-expanding stents. Also, the stent diameter of a balloon-expandable stent can be adjusted with greater accuracy after deployment. The restenosis rate or risk of acute thrombosis would be very low because of the large caliber and high flow rates in the aorta. Initial success rates are greater than 90%, with 5-year patency rates reported at 70%.1-6

Self-expanding stents were used to treat the left iliac artery dissection. Wall apposition of the stent to a vessel with a tapering diameter is better with self-expanding stents. The initial placement was at the origin of the common iliac artery. Not infrequently, this would tack down the intimal flap eliminating the flow disturbance in the remainder of the iliac artery. In this patient, however, a second iliac stent was needed to restore hemodynamic and angiographic patency. Once the second stent was placed, the patient had an easily palpable femoral pulse. The restoration of pulsatile flow portends clinical success.
CONCLUSION
Isolated aortic occlusive disease is not common. When significant disease is identified, the high-flow characteristics of this vessel make it ideal for endovascular intervention. The technical ability to use IVUS and large-caliber balloons and stents are an obvious requirement. The clinical benefit of aortic intervention outpaces all other vascular territories. 

Jason S. Carlson, RT, is from the Department of Endovascular Surgery, Division of Surgery, Greenville Hospital System, Greenville, South Carolina. He holds no financial interest in any product or manufacturer mentioned herein. Mr. Carlson may be reached at (864) 455-3180; jcarlson@ghs.org.

Bruce H. Gray, DO, is from the Department of Endovascular Surgery, Division of Surgery, Greenville Hospital System, Greenville, South Carolina. He receives educational support through Cordis Endovascular. Dr. Gray may be reached at (864) 455-5122; bhgray@ghs.org.

1. Charlebois N, Saint-Georges G, Hudson G. Percutaneous transluminal angioplasty of the lower abdominal aorta. Am J Radiol. 1986;146:369-371.
2. Odunry A, Colapinto RF, Sniderman KW, et al. Percutaneous transluminal angioplasty of the abdominal stenosis. Cardiovasc Intervent Radiol. 1989;12:1-6.
3. Tegtmeyer CJ, Kellum CD, Kron IL, et al. Percutaneous transluminal angioplasty in the region of the aortic bifurcation: the two balloon technique with results and long-term follow-up study. Radiology. 1985;157:661-665.
4. Martinez R, Rodriguez-Lopez J, Dietrich EB. Stenting for abdominal aortic occlusive disease: long-term results. Tex Heart Inst J. 1997;24:15-22.
5. d’Othee BJ, Haulon S, Mounier-Vehier C, et al. Percutaneous endovascular treatment for stenosis and occlusions of infrarenal aorta and aortoiliac bifurcation: midterm results. Eur J Vasc Endovasc Surg. 2002;24:516-523.
6. Rosset E, Malikov S, Magnan PE, et al. Endovascular treatment of occlusive lesions in the distal aorta: mid-term results in a series of 31 consecutive patients. Ann Vasc Surg. 2001;15:140-147.

 

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