Report of an Undeployed Stent Causing the Unraveling of a Coronary Artery Guidewire Being Used for Sidebranch Protection

Coronary guidewire fracture and subsequent retrieval of the retained pieces is an uncommon, but known complication of percutaneous coronary angioplasty. To our knowledge, however, this is the first report of a coronary guidewire unraveling after positioning an undeployed stent, and its successful retrieval by removal of the undeployed stent. Case Report. A 70-year-old male who had hypertension and hypercholesterolemia was treated with primary angioplasty of his proximal right coronary artery during an acute myocardial infarction 10 weeks prior to this admission. Because of continued anginal pain and a reversible perfusion defect on an adenosine dual isotope scan despite being on maximally tolerated medical therapy, he was now undergoing elective angioplasty of the left anterior descending (LAD) artery. The lesion was a complex, subtotal occlusion in the mid portion of the LAD with significant disease extending to its distal portion and a 2.0 mm second diagonal branch arising in the middle of the lesion. A 6 French JL4 Wiseguide guiding catheter (Boston Scientific/Scimed, Inc., Maple Grove, Minnesota) was positioned in the ostium of the left main coronary artery through a 6 French sheath in the right femoral artery. After 325 mg of oral aspirin was given, a weight-adjusted heparin bolus of 70 units/kg followed by a tirofiban bolus of 10 mg/kg and continuous drip of 0.15 µg/kg were administered. A 300 cm x 0.014´´ Hi-Torque Balance Middle Weight (BMW) guidewire (Guidant Corporation, Temecula, California) was then advanced through a dual opening hemostatic device at the proximal end of the guiding catheter, down the LAD and past the lesion. Next, a 190 cm x 0.014´´ BMW guidewire was easily advanced down the second diagonal branch to protect it during angioplasty of the LAD. A 2.5 x 20 mm OpenSail balloon catheter (Guidant Corporation) was then advanced over the LAD lesion and 4 inflation/deflation cycles were successfully performed up to a maximum of 8 atmospheres (atm). Because of a small dissection in the LAD, it was decided to place a 2.5 x 28 mm Tetra coronary stent (Guidant Corporation). Clopidogrel 300 mg was administered orally. The stent was easily advanced down the guidewire and positioned appropriately over the lesion. After confirming placement of the stent with cineangiography, the short BMW wire in the diagonal branch, which had been used as a landmark for proper positioning, was to be withdrawn prior to deployment of the stent. However, when removing the wire under fluoroscopic guidance, the radio-opaque distal tip was noted to remain stationary in the diagonal branch (Figure 1). Further attempts at removal of the short BMW wire eventually revealed that the wire had spontaneously unraveled and was only attached by the thin unwound coil tip. At that point, the undeployed stent in the LAD and its associated wire were removed under fluoroscopic guidance by one operator while another maintained traction on the proximal end of the diagonal branch wire, at which time the tip of the short BMW wire in the diagonal branch was also removed. The entire system, including the guiding catheter, was removed through the sheath. All of the equipment was accounted for on the sterile field and careful fluoroscopic inspection confirmed that no foreign bodies were left in the coronary arterial system. A new guide and 300-cm long BMW wire were reintroduced and the stent was subsequently placed without further incident. Discussion. Fracture of the coronary guidewire and subsequent retrieval of the retained pieces is an uncommon, but known complication of percutaneous coronary angioplasty. In the pre-stent era, a reported series of 5,400 consecutive percutaneous angioplasty procedures had a 0.2% incidence of some type of inadvertently retained equipment.1 A more recent surgical report retrospectively evaluated 5,614 consecutive coronary angioplasty procedures and found a 0.05% incidence of cases requiring surgical retrieval of retained guidewire fragments.2 Commonly, the fractured guidewire has required substantial manipulation in order to place it in a tortuous branch, but that was not the case with this intervention (Figure 2). With the widespread use of stents, previous reports of embolization of undeployed or partially deployed stents and their retrieval techniques have been published.3,4 To our knowledge, however, this is the first report of a coronary guidewire unraveling after positioning an undeployed stent, and its successful retrieval by removal of the undeployed stent. It would appear that positioning the undeployed stent created the wire rupture, since the distal tip of the short guidewire was retrievable by pulling the stent and its long guidewire out. The diagonal branch wire that unraveled had been easily advanced into position with a minimal amount of torque, so it is unlikely that it was damaged during placement. Further, the stent was easily advanced over its guidewire, so it does not appear that the two wires had overlapped or were twisted. Repeated inspections showed the guidewire tip to be positioned in the central lumen of the diagonal. Therefore, it seems as if the sidebranch wire “snagged” on the undeployed stent during removal, causing the unraveling. Since sidebranch protection with a double-wire system is a frequent technique when performing complex angioplasty cases, the interventionalist should be aware of this unusual complication as well as this strategy of retrieving the unraveled guidewire. Occasionally, interventionists will perform “triple-wiring”, in which a stent is deployed at low pressure and the sidebranch wire is left in place to act as a road map for a third wire in the event of sidebranch occlusion. In this case, deployment of the stent over the sidebranch guidewire would have made retrieval of the wire impossible and would have necessitated either surgical extraction or leaving the wire to likely thrombose in a relatively long 2.0 mm diagonal branch. Although sidebranch protection and placement of a stent with the guidewire left in place is commonly performed without complication, it should be realized that this practice is not without hazard because of the unusual, but serious consequences that could ensue if the entrapped wire were to unravel.

1. Hartzler GO, Rutherford BD, McMonahay DR. Retained percutaneous transluminal coronary angioplasty equipment components and their management. Am J Cardiol 1987;60:1260–1265. 2. Morris RJ, Kuretu MLR, Grunewald KE, et al. Surgical treatment of interventional coronary angiographic accidents. Angiology 1999;50:789–795. 3. Eeckhout E, Stauffer JC, Goy JJ. Retrieval of a migrated coronary stent by means of an alligator forceps catheter. Cathet Cardiovasc Diagn 1993;30:166–168. 4. Foster-Smith KW, Garratt KN, Higano ST, Holmes DR Jr. Retrieval techniques for managing flexible intracoronary stent misplacement. Cathet Cardiovasc Diagn 1993;30:63–68.