Clinical History
A 71-years-old lady came to our hospital with right-sided claudication in the leg 18 months after primary stenting of the right common iliac artery.
Imaging Findings
The initial angiogram revealed an occlusion of the right common and external iliac artery. 18 months ago, three stents had been deployed in the commoniliac (balloon-expandable stents 8x37 mm-Scuba Invatec). Collateral branches reperfuse the common femoral artery (CFA) (Fig.1a). The occlusion was negotiated easily in a retrograde approach from the right side with a straight stiff hydrophilic guidewire. However, considering the length of occlusion, it was decided to try to reopen the right iliac artery with local fibrinolysis with urokinase over a 24 hours period. The following day the angiogram showed a persistent occlusion of the right iliac artery (Fig.1b). Taking into account that the occlusion was already crossed, we tried to reopen the occluded artery with balloon angioplasty (PTA). After PTA we checked the result with hand injection from the introducer sheath inserted in the right CFA. The result appeared quite satisfactory (Fig. 2a). However, in order to achieve a more precise overview of the result, we repeated the angiography with contrast injected into the distal aorta with an acceptable result in terms of recanalisation of the iliac artery but with an unexpected finding: the most proximal stent, deployed 18 months ago, moved now freely in the distal aorta (Fig. 2b,c). It was decided to engage the stent with a guidewire (Fig. 3a,b) and, using an inflated balloon catheter, the stent was pulled back into the proximal common iliac artery (Fig. 3c). The stent was fastened with an instent-stenting using a stent similar to the previously used stent (Scuba-Invatec) (Fig. 3d). The final angiogram shows a satisfactory result (Fig. 3e).
Discussion
A successfully deployed stent is normally stable in position and unlikely to be dislodged. We report a case of stent dislodgement 18 months after successful implantation in a patient who underwent local fibrinolytic therapy for 24 hours, re-negotiation of the stent lumen and re-ballooning of the stent. This complication is extremely rare. We found a few case reports in coronary endovascular interventions [1, 2] and one case report in a patient with stent-graft implantation two months prior in order to treat an iliac artery aneurysm [3]. Generally stents are stable in position and it is well known that intimal hyperplasia covers the struts and stabilises the stent. We never observed a similar complication in our experience. A possible explanation for the dislodgement might be that the stent had been undersized in the previous treatment or that the stent was deployed on a mural thrombus so that during endovascular recanalisation done after fibrinolytic therapy the movements of the PTA balloon catheter could dislodge the stent. Another explanation for this complication would be a subintimal pathway of the guidewire during the attempted recanalization. We exclude this possibility for two reasons: first, crossing the occlusion was very easy and second we used a straight stiff hydrophilic guidewire which usually stays intraluminal. Fortunately, no adverse event occurred as a consequence of this dislodgement. Furthermore, in this case we want to emphasise the importance to always check what happens distally to the site of treatment where your guidewires and catheters move. Also, focusing the check angiogram only at the level of the treated lesion should be avoided.
Differential Diagnosis List
Stent dislodgement and repositioning during iliac artery re-recanalisation.
Final Diagnosis
Stent dislodgement and repositioning during iliac artery re-recanalisation.
