Early Occlusive Restenosis Due to Self-Expandable Stent Squeeze
in the Popliteal Artery
Self-expandable stent fracture may occur when the stent is implanted in peripheral arteries near or at flexion points.1 However, stent squeeze is quite rare, especially early after implantation. We report a case of a patient with an occlusive restenosis due to cross-sectional squeeze and deformation of a self-expandable stent in a popliteal artery 1 month after implantation.
Case Report
A 25-year-old male smoker, semiprofessional soccer player was referred to our hospital because of intermittent claudication of the right leg. He experienced right limb trauma while playing soccer with onset of intermittent claudication 2 weeks thereafter. A duplex ultrasound of the inferior limbs revealed a patent left iliac-femoral axis and complete occlusion of the right superficial artery with demodulated flow at the level of the popliteal artery. Magnetic resonance imaging of the right limb showed normal femoral muscle and ligament insertion to the patella articulation. Selective right femoral angiography showed complete occlusion of the superficial femoral artery at the level of the Hunter channel and distal recanalization of the popliteal artery (Figure 1). The occlusion was mechanically revascularized after crossing with a 0.014 Pilot 150 hydrophilic wire (Guidant Corp., Indianapolis, Indiana) and placement of a 7 x 80 mm self-expandable Maris nitinol stent (Invatec, Roncadelle, Brescia, Italy), with an excellent final result (Figure 2). One month later, after playing a soccer game, the patient complained of acute recurrence o f claudication (Fontaine IIb). A duplex examination revealed reocclusion of the right popliteal artery at the level of stent placement. Control angiography via a contralateral approach showed total occlusion of the stented segment (Figure 3). The stent was squeezed along the short axis in the mid-distal portion, with partially fractured struts. Despite several attempts, we were unable to cross a 0.018 V-18 Control Wire hydrophilic guidewire (Boston Scientific Corp., Natick, Massachusetts) through the occluded stented segment using a 6 Fr, 45 cm-long sheath, a 6 Fr JR 4.0 guiding catheter and a 5 Fr Strait Taper support catheter (Terumo, Tokyo, Japan). Thus, we decided to use an antegrade approach to improve backup and wire control. A 6 Fr sheath was then inserted into the right superficial femoral artery and the V-18 guidewire was finally able to cross through the occlusion with support of the 5 Fr Terumo catheter. However, it was impossible to advance a 5.0 mm Sterling balloon (Boston Scientific) through the occluded stented segment. After exchanging the V-18 guidewire for a 0.014 stiff Skipper Deep guidewire (Invatec), we were able to cross a 2.5 x 80 mm Amphyrion hydrocoated balloon (Invatec). After predilatation, it was clear that the guidewire went out thorough the stent struts, passed beside the squeezed stent segment, and then recrossed into the stent (Figure 4A), maintaining an intraluminal position (Figure 4B). Thus, after additional predilatation with the 5.0 mm Sterling balloon, an additional 6 x 80 mm Smart self-expandable nitinol stent (Cordis Corp., Miami Lakes, Florida) was deployed. Final angiography showed good distal runoff with 28% residual lumen stenosis by online quantitative angiography (Figure 4C). The patient has been asymptomatic for claudication since. Computed tomographic (CT) angiography of the right leg in knee flexion and dorsiflexion 5 months after the procedure showed a patent right popliteal artery without external stent compression (Figures 5A and B).
Discussion
Self-expandable stent fracture of the popliteal artery may occur at the level of arterial flexion usually several months after implantation.1 To the best of our knowledge, this is the first report of a patient with cross-sectional stent squeeze accompanied by stent fracture early after implantation at the level of the femoropopliteal artery.
Although it has conventionally been reported that an abnormal relationship of the popliteal artery to the gastrocnemius muscle, or an anomalous fibrous band or the popliteus muscle, cause popliteal artery entrapment syndrome, a “functional” popliteal artery entrapment syndrome has recently been described in patients with normal anatomy, which isusually found in well-conditioned athletes.2 However, CT angiography with dynamic maneuvers of the foot 5 months after the procedure refuted the possibility of this syndrome in our patient. Forces exerted in the popliteal artery, such as torsion, compression, contraction and extension during an intense football game could be important factors in the pathogenesis of stent squeeze with partial fracture.1 In addition, our case suggests that self-expandable stents with greater radial force are needed to avoid this rare phenomenon.
Bypass surgery is recommended as the primary treatment for femoropopliteal occlusive disease.3 However, balloon angioplasty and stenting have some advantages over bypass surgery, such as low morbidity and mortality, shorter recovery and preservation of the saphenous vein for future bypass surgery, especially in young patients. According to the patient’s wishes, we implanted an additional stent to recanalize the occluded artery. The stent was patent at 5-month follow up. However, close clinical observation is needed since long-term results of additional stenting in this specific lesion are unknown. Surgical revascularization should be selected in the setting of re-restenosis or re-occlusion.
References
1. Scheinert D, Scheinert S, Sax J, et al. Prevalence and clinical impact of stent fractures after femoropopliteal stenting. J Am Coll Cardiol 2005;45:312–315.
2. Wright LB, Matchett WJ, Cruz CP, et al. Popliteal artery disease: Diagnosis and treatment. Radiographics 2004;24:467–479.
3. Dormandy JA, Rutherford RB. Management of peripheral arterial disease (PAD). TASC Working Group. TransAtlantic Inter-Society Consensus ( TASC). J Vasc Surg 2000;31:S1–S296.
