Retrieval of a Detached Partially Expanded Stent Using the SpideRX and EnSnare Devices — A First Report

Case Report. A 66-year-old male with previous two-vessel coronary artery bypass graft surgery (CABG) presented with an acute coronary syndrome. Angiography demonstrated a critical 95% stenosis in the ostium of the saphenous vein graft (SVG) to the obtuse marginal (OM) of a dominant circumflex vessel, and another 70% thrombotic lesion in the mid portion of the same graft (Figure 1). The left internal thoracic artery (was widely patent, supplying a diffusely diseased distal left anterior descending artery not amenable to percutaneous intervention. Intervention was performed on the SVG to the OM.
A 6 Fr left coronary bypass guiding catheter was engaged into the graft and an ExtraSport wire (Guidant Corp., Santa Clara, California) was passed distally. A SpideRX 4.0 mm distal protection device (ev3, Inc., Plymouth, Minnesota) was introduced and deployed well distal to the mid-body lesion after predilatation of the ostial lesion with a 2.5 mm balloon at low pressure. Next, an attempt to pass a 4.0 x 12 mm Taxus^® drug-eluting stent (DES) (Boston Scientific Corp., Natick, Massachusetts) to the mid lesion was not successful (Figure 2). In the process of withdrawal, the stent edge caught on the guider tip, and in spite of coaxial alignment, the stent became detached off its balloon and was positioned half in the aorta and half in the ostium of the graft (Figure 3). Initially, a 1.5 mm balloon was advanced through the detached stent and distal to it over the same SpideRX^™ wire and was inflated to 8 atm. An attempt to withdraw the balloon/stent combination into the guiding catheter was not successful since this inflated balloon passed through the detached stent, in fact partially expanding it to some degree (Figure 4).

Next, the same maneuver was tried with a larger 2.0 mm balloon to capture the stent into the guiding catheter, but once again, the balloon passed through the stent, expanding it a little further. We were now faced with a partially expanded stent that would not be able to be captured into a 6 Fr catheter (Figure 5). At this point our only option was to remove the stent safely from the coronary circulation. The retrieval end (blue color) of the SpideRX retrieval catheter was advanced through the guider to the proximal end of the stent and the open/deployed SpideRX filter was gently withdrawn through the graft to the distal end of the detached stent while keeping a gentle forward pressure with the retrieval catheter so as to sandwich the detached prosthesis between the SpideRX basket and the SpideRX retrieval catheter. This entire unit was then removed in total to the right femoral sheath (Figure 6). Due to the expanded state of the stent, it was also not possible to pull this unit out through the right femoral 6 Fr sheath. This hardware was left in the right femoral artery temporarily. Contralateral access was obtained in the left femoral artery with another 6 Fr sheath and a JR4 guiding catheter was engaged into the graft. After administration of prophylactic adenosine and nitroprusside, direct stenting of the mid-body lesion was performed with a 3.5 x 12 mm Liberté stent (Boston Scientific Corp.) and a 3.5 x 20 mm Taxus DES was deployed at the ostium and proximal segment at high pressures and further postdilated with a 4.0 mm noncompliant balloon at high pressure. An optimal angiographic result was obtained (Figure 7).

Next, the left femoral artery sheath was upsized to an 8 Fr Balkin sheath (Cook Cardiology, Bloomington, Indiana), which was passed in a retrograde fashion into the right iliac artery. The EnSnare device was loaded into the Balkin sheath via its introducer, and rotational motion was utilized to trap the tip of the SpideRX 4.0 mm device and this was withdrawn into the sheath. Unfortunately, due to resistance at the Balkin sheath tip, the tip separated from the remainder of the SpideRX filter. A second attempt was successful in capturing the actual SpideRX filter basket, and with some effort, this was externalized via the Balkin sheath (Figure 8). There was no Taxus stent seen, however, within the basket, and repeat fluoroscopy showed that the detached and deformed stent was still in the right iliac artery, still over the proximal end of the SpideRX wire (Figure 9). This was also snared and brought into the Balkin sheath separately while a second operator was feeding the proximal end of the SpideRX wire towards the direction of the Balkin sheath and left femoral artery. All three components of the unit were removed successfully (Figure 10). The right femoral artery was manually compressed with good hemostasis and some hematoma with a similar reasonable result in the left femoral artery. Although there was a significant drop in hemoglobin, two computed tomographic scans of the abdomen demonstrated no evidence of retroperitoneal hemorrhage, and only subcutaneous hematoma was visualized. The patient did require 2 units of packed red blood cells with a hemoglobin of 12 g/dl 5 days post discharge. The patient was discharged in good condition 72 hours post procedure.

Discussion. Stent dislodgement from its balloon can be a potentially devastating complication with risks of coronary occlusion, thrombosis, myocardial infarction and requirement for emergency CABG.⁶
Deployment of an undeliverable stent at a different site is sometimes a reasonable option if it cannot be withdrawn into the guiding catheter. The initial undeliverable stent was not implanted at the ostial lesion due to its shorter length and larger size than required for the ostium. If a lot of resistance had been felt during withdrawal into the guiding catheter, then certainly the best option would have been to deploy this stent at the ostium, however, this was not the case here. It is suspected, however, that partial stent detachment occurred during the push forward while trying to advance the stent initially to the distal lesion, resulting in complete detachment during even gentle withdrawal. The other lesser concern regarding ostial deployment would be the potential inability to pass a second stent through the ostial stent (since ostial stents are usually deployed 1–2 mm into the aorta to ensure complete ostial coverage). The small distal balloon technique was utilized as the first retrieval technique, since it is well described as the most common and simple technique and has moderate success.⁶ The logic behind this technique is to trap the stent proximal to a small inflated balloon and then withdraw this safely into the guiding catheter with the potential to externalize the detached stent via the sheath. The benefit with this technique is that wire location beyond the lesion is maintained while having the detached device over the wire at all times. Although the snare technique was contemplated as the initial retrieval method, our wire of choice in this case was the SpideRX wire with attached basket, and not simply a regular wire. The snare technique entails trapping the detached stent and its wire both and withdrawal of the complete unit. This would have exposed the graft to the risk of withdrawal of the open basket through its length, risking dissection and endothelial damage. It must be stated that although this higher-risk method of removal of an open basket was eventually performed to allow stent trapping, we tried to avoid this initially by trying lower-risk and potentially safer techniques such as the “distal small balloon” method. If this was a case with a regular wire (no attached basket), then certainly utilizing the snare technique as an initial strategy would be very reasonable. The ability to retrieve and remove a detached stent from the coronary circulation is an essential tool in percutaneous intervention. We describe the first reported use of a SpideRX distal protection filter device to capture and retrieve not only a detached but also a partially expanded stent from the ostium of a SVG. The subsequent use of a snare device was required to externalize the deformed stent and filter device via the contralateral femoral artery with the use of a larger 8 Fr sheath. This is not a low-risk technique and should only be utilized after exhausting several other retrieval methods. Movement of an open-profile SpideRX device through a vessel may disrupt plaque or thrombus or causing dissection in its path back to the detached stent. Although we were fortunate that neither occurred with our patient, this cannot be assumed every time. However, in a difficult scenario with a partially expanded stent, this technique in our case allowed salvage of a critical situation. We would recommend always starting with lower-risk methods for stent retrieval first and progressing to more complex methods in a graded fashion depending on operator expertise. Surgical consultation and backup is always critical in such situations.

References

1. Rozenman Y, Burstein M, Hasin Y, Gotsman MS. Retrieval of occluding unexpanded Palmaz-Schatz stent from a saphenous aorto-coronary vein graft. Cathet Cardiovasc Diagn 1995;34:159–161.
2. Veldhuijzen FL, Bonnier HL, Michels HR, et al. Retrieval of undeployed stents from the right coronary artery: A report of two cases. Cathet Cardiovasc Diagn 1993;30:245–248.
3. Elsner M, Peifer A, Kasper W. Intracoronary loss of balloon-mounted stents: Successful retrieval with a 2 mm “Microsnare” device. Cathet Cardiovasc Diagn 1996;39:271–276.
4. Wongpraparut N, Yalamachili V, Leesar MA. Novel implication of combined stent crushing and intravascular ultrasound for dislodged stents. J Invasive Cardiol 2004;16:445–446.
5. Webb JG, Solankhi N, Carere RG. Facilitation of stent retention and retrieval with an emboli containment device. Catheter Cardiovasc Interv 2000;50:215–217.
6. Brilakis ES, Best PJM, Elesber AA, et al. Incidence, retrieval methods, and outcomes of stent loss during percutaneous coronary intervention. Cathet Cardiovasc Interv 2005;65:333–340.