Stenting for Proximal Para-Anastomotic Stenosis

Abstract

We present a case in which endovascular stenting was used for recurrent proximal para-anastomotic stenosis 11 years after aorto-bi-iliac bypass grafting for severe aortoiliac occlusive disease. A 55-year-old woman presented with worsening bilateral hip and buttock claudication. At presentation, her resting ankle-brachial indices were 0.87 bilaterally and decreased to 0.39 on the right and 0.40 on the left with exercise. Aortography demonstrated a proximal para-anastomotic aortic graft stenosis without distal outflow obstruction, patent superficial femoral arteries, and good triple-vessel runoff bilaterally.

The stenosis was dilated with a 9- × 4-cm OPTA balloon angioplasty catheter. A Palmaz stent (P424, Cordis) was mounted on a 10- × 4-cm OPTA balloon catheter and deployed across the proximal stenosis. Completion arteriography confirmed adequate placement and reduction in the degree of stenosis. There was no pressure gradient across the proximal anastomosis. At our patient's 1-week follow-up visit, her resting ankle-brachial indices were both greater than 1.0 and her exercise ankle-brachial indices were 1.0 bilaterally. She remained asymptomatic at 13 months.

Most late sequelae of aortic graft surgery involve the distal anastomosis and are resolved surgically without complicated techniques. However, revision at the proximal anastomosis involves the aorta directly and therefore requires open abdominal dissection and aortic cross-clamping. Percutaneous aortic stenting for primary aortoiliac disease has been shown to reduce operative time, cost, and hospital stays, to improve patency, and to be durable. Our clinical experience with aortic stenting for primary disease led us to consider this procedure for recurrent proximal stenosis. (Tex Heart Inst J 2002;29:45–7)

Proximal para-anastomotic graft stenosis is an uncommon complication after infrarenal aortic bypass surgery. The incidence of late stenosis arising from the proximal anastomosis after aortic reconstructive surgery has been reported to be as high as 6%. ¹ The traditional management has been surgical revision, which has involved considerable morbidity and mortality. An endovascular approach to stenosis of aortic grafts might be an attractive alternative, given the successful results demonstrated by stenting of aortic occlusive disease. ^2–10 We present a case in which endovascular stenting was used for recurrent proximal para-anastomotic stenosis 11 years after aortic bypass grafting.

Case Report

In November 2000, a 55-year-old woman presented with worsening bilateral hip and buttock claudication. Eleven years before (July 1989), she had undergone aorto-bi-iliac bypass grafting for severe aortoiliac occlusive disease, and she had remained asymptomatic for the following 10 postoperative years. Her medical history included hyperlipidemia, coronary artery disease, migraine headaches, and degenerative disc disease. Her most recent total serum cholesterol level had been 341 mg/dL with medical therapy, but it had been as high as 700 mg/dL prior to therapy. She had quit cigarette smoking in 1989, after a 20 pack-year history. She had no palpable distal pulses in the lower extremities.

At presentation, her resting ankle-brachial indices were 0.87 bilaterally and decreased to 0.39 on the right and 0.40 on the left with exercise. Duplex ultrasonic examination showed increased velocities in the aortic graft proximal to the bifurcation. Aortography demonstrated a proximal para-anastomotic aortic graft stenosis without distal outflow obstruction, patent superficial femoral arteries, and good triple-vessel runoff bilaterally (Fig. 1).

Fig. 1 Angiogram of the aortic graft shows a proximal para-anastomotic aortic graft stenosis (arrow) without distal out-flow obstruction, patent superficial femoral arteries, and good triple-vessel runoff bilaterally.

The procedure was performed under general anesthesia in an operating suite with dedicated angiographic equipment. Percutaneous intravascular access was obtained through the right common femoral artery with a 9-F sheath. Heparin (5000 U) was administered and an arteriogram was performed via a pigtail catheter. Intravascular ultrasound (IVUS) showed the stenosis and a normal aortic size of 10 mm proximal to the stenosis (Fig. 2). We used a catheter pull-through technique to serve a dual purpose: to measure the pressure gradient across the proximal anastomosis (which was found to be 40 mmHg), and to measure the length of the lesion. The stent type and size were selected on the basis of this information. The stenosis was dilated with a 9- × 4-cm OPTA balloon angioplasty catheter (Cordis; Miami Lakes, Fla). A Palmaz stent (P424, Cordis) was mounted on a 10- × 4-cm OPTA balloon catheter and deployed across the proximal stenosis. Completion arteriography confirmed adequate placement and reduction in the degree of stenosis (Fig. 3). After deployment, there was no pressure gradient across the proximal anastomosis. The duration of the procedure was 35 minutes, and 120 cc of contrast medium was administered. Intravascular ultrasound demonstrated good stent expansion and apposition.

Fig. 2 Intravascular ultrasonography shows the stenosis.

Fig. 3 Repeat angiogram at completion confirms adequate placement of the stent (arrow) and reduction in the degree of stenosis.

The patient had palpable pedal pulses after the procedure. She had an uneventful hospital course and was discharged the following morning. At her 1-week follow-up visit, her resting ankle-brachial indices were both greater than 1.0 and her exercise ankle-brachial indices were 1.0 bilaterally. She remained asymptomatic at 13 months. On 22 January 2002, follow-up duplex ultrasonography showed a patent stent with normal velocities.

Discussion

Reported late sequelae of aortic graft surgery include graft thrombosis, occlusion, stenosis, infection, pseu-doaneurysm, and enteric fistula. ^1,8,11 Most late problems involve the distal anastomosis and are repaired without complicated operative techniques. However, surgical revision at the proximal anastomosis is a complex procedure that involves the aorta directly and therefore requires open abdominal dissection and aortic cross-clamping. The procedure carries a morbidity rate that is often as high as 3%. ¹

Percutaneous aortic stenting for aortoiliac disease has been shown to be successful and durable. ^2–10 An endovascular approach to aortoiliac disease has been demonstrated to reduce operative time, costs, and hospital stays, while improving patency to a rate approaching 100%. ⁷ This approach also obviates the possibility of neural damage and subsequent impotence, which is sometimes a result of surgical intervention. ¹² The mortality in most series is close to zero, and the morbidity rate has been shown to be lower than that associated with open surgical bypass. ⁷ If the aorta can be stented for primary disease, should we not consider stenting for recurrent stenosis in proximal aortic graft anastomosis? Our clinical experience with aortic stenting for primary disease has led us to consider this procedure for recurrent proximal stenosis.

Our patient originally had an aorto-bi-iliac artery bypass for severe disease at a relatively young age. Although the aorto-bi-iliac bypass has been shown to be a durable operation, our middle-aged patient with severe hyperlipidemia should be expected to have progression of occlusive disease in her lifetime. After 10 years, her onset of new claudicant symptoms indicated problems with her graft. We discussed operative strategies with the patient and decided to perform an aortic stenting procedure. Because of the configuration of the end-to-side proximal anastomosis, the stent selected for this patient was a Palmaz 424, which combines radial force with the flexibility necessary to conform to the anastomosis.

The procedure's success continued to be demonstrated at her 13-month follow up and she remained free of symptoms.