Successful endovascular management of popliteal artery adventitial cystic disease with expanded polytetrafluoroethylene stent graft reinforced with interwoven nitinol stent

Abstract

Popliteal adventitial cystic disease has traditionally been treated with open surgery of cyst excision, patch repair of artery, or interposition graft. Endovascular angioplasty or stenting has demonstrated poor mid- to long-term results because high-viscosity tension of the adventitial cyst continues to exert extrinsic compression, resulting in early elastic recoil and disease recurrence. To our knowledge, this is the first report in the literature of an effective endovascular strategy using a popliteal stent graft reinforced with an interwoven nitinol stent to treat popliteal cysts, with favorable short- and mid-term outcome. Antiplatelet therapy should be continued, and patient should undergo regular clinical and duplex surveillance to ensure popliteal artery patency.

Cystic adventitial disease is a rare disease entity involving both the arterial and venous systems and is most commonly found at the popliteal artery.¹ Clinically, it often presents with either sudden-onset debilitating claudication, which resolves but recurs later, or progressively worsening.² Some patients may give a history of trauma.¹ A wide range of treatment modalities have been reported. The conventional management involves open surgery with excision of the affected artery followed by interposition bypass grafting, or cyst resection followed by patch repair or bypass.³ The clinical outcome of percutaneous aspiration of cysts is not effective and may recur, whereas endovascular of balloon angioplasty and bare metal stenting were unsuccessful with high recurrence rate of 67%.¹

We report a patient suffering from left renal cell carcinoma with symptomatic left popliteal artery adventitial cystic disease being successfully treated with endovascular expanded polytetrafluoroethylene stent graft reinforced with interwoven nitinol stenting.

Case summary

A 56 years old gentleman, with a past medical history of hypertension and hyperlipidemia, presented to his doctor with sudden-onset debilitating left leg claudication of less than 5 minutes, but symptoms gradually improved after the subsequent 2 months back to normal. Physical examination at the time showed a regular pulse and diminished left popliteal and distal pulse. Magnetic resonance imaging showed 90% stenosis of the left popliteal artery, suspicious for popliteal artery adventitial cystic disease (Fig 1, A).

Fig 1.

Preoperative contrast magnetic resonance angiogram (A), demonstrating left popliteal artery significant stenosis and occlusion due to adventitial cyst (arrowed). Preoperative lower limb contrast computed tomography angiogram (B), showing left popliteal stenosis and left renal lower pole mass (arrowed).

He was referred to our institution, a tertiary vascular referral center, at which stage he had recurrent symptoms of left leg claudication, coldness, and numbness of the left foot for the past week. His ankle-brachial pressure index was 1.17 on the right and 0.55 on the left. Duplex ultrasound showed severe stenosis of the left popliteal artery. Emergency-contrast computed tomography angiogram of the aorta and both legs incidentally revealed a left renal tumor suggestive of renal cell carcinoma without metastasis and severe stenosis of the left popliteal artery with preserved distal runoff (Fig 1, B).

The patient was very alarmed by the incidental finding of left renal tumor. We advised conventional treatment option with open cyst excision followed by patch or bypass reconstruction; however, he strongly requested minimally invasive endovascular management as he wished for a fast vascular postoperative recovery and then proceed promptly with urological workup and definitive surgery. He was given intravenous heparin infusion during the perioperative period, with activated partial thromboplastin time of 50 to 60 seconds. During the operation, angiography showed stenosis of the left popliteal artery, and intravascular ultrasound study (Volcano Corporation, Phillips) showed cystic adventitial disease at P2 causing significant stenosis and thrombosis of 1.5 cm in length (Fig 2, A and B). The thrombus was suspected to be acute-on-chronic as the patient had sudden onset of debilitating claudication after a period of stability. Otherwise, the superficial femoral artery was patent with three below knee vessel runoffs. He underwent endovascular thrombectomy (Penumbra Lightning 7, Penumbra Inc), followed by covered stenting (8 × 50 mm GORE VIABAHN, W. L. Gore & Associates, Inc) and balloon molding (8 × 40 mm Admiral Xtreme PTA Catheter, Medtronic). The results were satisfactory on angiogram and intravascular ultrasound study, but in view of the stent graft in a very flexible joint area, this was further reinforced with an interwoven nitinol stent (7.5 × 40 mm SUPERA, Abbott Medical) and poststent balloon molding (7.5 × 40 mm Admiral Xtreme PTA Catheter, Medtronic). Completion angiogram showed patent popliteal artery with good luminal gain and brisk flow down to foot (Fig 2, C).

Fig 2.

Intraoperative intravascular ultrasound study (A), showing the cyst (arrowed) causing P2 significant stenosis and thrombosis. Contrast angiography (B), and completion angiogram (C), after thrombectomy, VIABAHN and SUPERA stents.

The patient resumed full mobility on postoperative day 1 and was discharged home on day 2. He received 3 months’ dual antiplatelet therapy (oral aspirin 100 mg daily and oral clopidogrel 75 mg daily), followed by lifelong clopidogrel. He underwent prompt workup and made good recovery from his curative resection of his left renal cell carcinoma also. Follow-up lower limb contrast computed tomography angiogram and duplex ultrasound study at 3 months’ time showed patent popliteal artery stent (Fig 3, A and B). There was no kinking or compression of the VIABAHN and SUPERA stents (Fig 3, C). Now at 6 months, he remained asymptomatic with palpable pedal pulses. The patient gave written consent for this paper to be published. Institutional Review Board approval is not required for case report publication.

Fig 3.

Postoperative follow-up contrast computed tomography angiogram (A), showing patent left popliteal artery, confirmed with duplex ultrasound study (B). Plain radiograph of VIABAHN and SUPERA stents (C).

Discussion

This is the first report in the literature of a patient with severe popliteal artery stenosis due to adventitial cystic disease, which was successfully treated with endovascular thrombectomy, and expanded polytetrafluoroethylene stent graft reinforced with an interwoven nitinol stent.

Adventitial cystic disease has traditionally been treated with open surgery of cyst excision, patch repair of artery, or interposition graft. There are case reports and small cohorts of patients treated with endovascular stenting, but the mid- to long-term results of angioplasty or stenting have been disappointing, as the underlying cause of high-viscosity tension of the adventitial cyst continues to exert extrinsic compression, resulting in early elastic recoil and disease recurrence. There were isolated cases of percutaneous aspiration of cysts,^4,5 followed by stenting, but as the popliteal artery is subjected to mechanical stress during locomotion, this is often complicated with stent fracture, artery occlusion, or even leakage of blood into the adventitial cyst.^6,7 The SUPERA stent alone may be able to maximize the radial force, but it is a nitinol bare stent, and the residual thrombus or cystic content may cause restenosis. That’s was why we chose a SUPERA stent inside a VIABAHN stent graft.

The VIABAHN stent graft has been used to treat popliteal aneurysm successfully if there are sufficient proximal and distal land zones. In addition, the VIABAHN stent graft and the SUPERA interwoven nitinol stent are both reliable endovascular devices in treating calcified femoropopliteal lesions. Horie et al⁸ reported that the two devices showed the similar efficacy in calcified femoropopliteal lesions, and our institution has extensive experience in the use of SUPERA stents in the popliteal artery with good results.⁹ The aim of the addition of the SUPERA stent reinforce the VIABAHN stent graft was to maximize the radial force while maintaining resisting external compression and maintaining stent flexibility. The simultaneous use of a nitinol interwoven SUPERA stent to reline VIABAHN endoprosthesis is a relatively new concept, so as to resist compression and contortion during locomotion. This technique has been described before to “crack-and-pave” treat calcified popliteal lesion, as well as to treat excessive kinking of arteries.10, 11, 12 MacTaggart et al¹³ showed in an in vivo experiment of seven stent designs deployed in femoropopliteal arteries of lightly embalmed human cadavers that compared with AbsolutePro (Abbott Vascular), Innova (Boston Scientific), Zilver (Cook Medical), SmartControl, SmartFlex (both Cordis), and VIABAHN (W.L. Gore & Associates). SUPERA had the highest radial strength, and all the other stents except SUPERA were pinched in flexed limb postures.

In our patient, the diameter of the normal popliteal artery was 7.8 mm before the stenosis, and 7.3 mm below the stenosis. VIABAHN diameter ranges from 5 mm to 13 cm, and SUPERA stent, outer diameter ranges from 4.5 to 7.5 mm. A 8 × 50 mm VIABAHN stent graft and a 7.5 × 40 mm SUPERA stent were chosen. Since the largest commercially available outer diameter of SUPERA is 7.5 mm, arterial diameter in excess of 9 to 10 mm may not be suitable. Nonetheless, our patient illustrated that the same technique can be used effectively in treating popliteal artery adventitial cystic disease with appropriate diameter. We emphasize that antiplatelet therapy should continue long term. Three-months’ dual antiplatelet therapy followed by lifelong clopidogrel is the standard treatment for all patients who underwent lower limb endovascular intervention. We believe the thrombus in this patient was due to severe stenosis caused by the cysts, and not due to emboli. Therefore, we chose the dual antiplatelet therapy and lifelong clopidogrel. An alternative would be to use nonvitamin K antagonist oral anticoagulant and aspirin, but this is not a routine regime use in our institution. Since endovascular failures may occur later due to persistent extrinsic compression, long-term surveillance beyond 1 year is essential to confirm that the nitinol reinforcement can prevent late elastic recoil.

Declaration

This article has not been submitted for presentation or publication elsewhere.

Funding

None.

Disclosures

None.