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Percutaneous snare retrieval of a partially embedded wallstent

Although removal of a stent is a well described method for treating an acutely dislodged or embolized device, removal of a previously deployed stent is unusual. We describe a case where a partially dislodged wallstent in a saphenous vein graft was removed using a snare to permit deployment of a balloon mounted stent across a proximal vein graft stenosis. Catheter Cardiovasc Interv 2004;61:400–402. © 2004 Wiley‐Liss, Inc.


INTRODUCTION
Retrieval of dislodged or embolized coronary stents is a rare occurrence in interventional cardiology [1,2]. Successful methods of managing this complication include the use of snares, baskets, a second wire, and a distally placed angioplasty balloon. A distal embolization protection device has also been used for the retrieval of a dislodged stent in a saphenous vein graft [3]. All of these cases occurred after acute loss of the stent. The following unique case describes the retrieval by snare of a partially embedded but dislodged self-expanding Wallstent from a saphenous vein graft.

CASE REPORT
The patient is a 68-year-old male with aortic stenosis and coronary artery disease resulting in aortic valve replacement and coronary bypass surgery in 1987 that included a saphenous vein graft to the posterior descending artery (PDA) and sequential vein graft to the diagonal branch and left anterior descending artery (LAD). Four months prior to admission, he presented with dyspnea and pulmonary congestion. The patient underwent repeat aortic valve replacement with a 23 mm Carpentier-Edwards (Edwards Lifesciences) bovine pericardium valve and also had a radial artery graft placed to the distal LAD and a new saphenous vein graft to the PDA. Two months later, he presented to a local hospital with an acute coronary syndrome. Coronary angiography showed a new 80% proximal stenosis of the vein graft to the LAD. A 4.5 mm self-expanding Magic Short Wallstent (Boston Scientific) was positioned across the stenosis. No postdilatation was performed.
Two weeks later, the patient presented to this hospital with recurrent chest pain and elevated troponin of 13.6 ng/ml. Angiography revealed that the Wallstent was protruding 10 mm into the aorta and the distal end no longer covered the stenosis (Fig. 1A). The patient was considered high risk to undergo repeat bypass surgery due to two previous operations and severely decreased ejection fraction of 23%. The partially dislodged stent was positioned such that deployment of a new stent coaxially, or along side of it into the graft, would be difficult. Thus, it was decided to remove the Wallstent with a snare.
An 8 Fr multipurpose guiding catheter with a 15 mm diameter snare was positioned near the proximal end of the Wallstent protruding into the aorta from the saphenous vein graft (Fig. 1B). The flexible self-expanding stent was successfully snared and removed via the 8 Fr femoral introducing sheath without difficulty (Fig. 1C). Subsequently, a successful angioplasty was performed with deployment of an Ultra (Guidant) 5.0 ϫ 18 mm balloon-expandable stent inflated to 16 atm and postexpanded to 20 atm (Figs. 1D and 2).

DISCUSSION
When retrieval of a partially deployed or embolized stent is not technically feasible due to the location of the stent in the coronary or peripheral circulation, a common technique is to compress the stent against the arterial lumen with a dilation balloon or second stent [4 -6]. In this reported case, this strategy would not be practical due to the location of the partially deployed Wallstent from the proximal anastamosis of the saphenous vein graft into the aorta. This case is also unusual in that the Wallstent had migrated from its original position. A possible explanation for this is that the self-expanding stent had not been postdilated. Additionally, during our predilation, the stenosis was noted to be rigid and consistent with fibrotic tissue, which may explain the tapering of the distal aspect of the stent and the proximal migration of the Wallstent. This proximal migration of the stent, and short time since insertion, may have contributed to the ease of removal.