Snare Removal of a Deformed Coronary Stent Via Radial Artery During Percutaneous Intervention for Acute Myocardial Infarction

ABSTRACT: A 49-year-old man underwent emergent coronary angiography for acute inferior myocardial infarction (MI).  After balloon angioplasty of culprit right coronary artery (RCA) occlusion, a Promus Element stent would not advance to the target lesion.  The proximal end of the stent became compressed against the tip of the guiding catheter, such that the stent could neither be advanced nor withdrawn.  This case illustrates the technical aspects of snare removal of a severely deformed stent via the radial artery.

J INVASIVE CARDIOL 2014;26(1):E5-E6

Key words: snare removal, deformed stent, radial intervention

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With current-generation stent platforms, percutaneous coronary intervention (PCI) has become simpler for the operator and safer for the patient. Despite this, stents may become deformed in the process of delivery to the target lesion. In rare cases, deformation may be so severe that the stent can neither be advanced to the target lesion nor withdrawn back into the guide catheter. A working knowledge of snare techniques is useful under these circumstances.

Case Report. A 49-year-old man with hypertension presented with 2 hours of severe, retrosternal chest pressure. A 12-lead electrocardiogram revealed inferior ST elevation. Emergent coronary angiography was performed via 6 Fr x 10 cm Glidesheath (Terumo Corporation) in the right radial artery. Injection of culprit right coronary artery (RCA) with 6 Fr JR-4 guiding catheter (Cordis Corporation) identified acute occlusion. The lesion was easily crossed with a Prowater wire (Abbott Vascular). Aspiration thrombectomy and balloon dilatation were performed, resulting in Thrombolysis in Myocardial Infarction (TIMI) grade-3 flow and identification of underlying ruptured plaque in the proximal to mid-segment of the RCA. A 4.0 x 32 mm Promus Element stent  (Boston Scientific) would not advance to the target lesion, likely due to tortuosity and calcification in the proximal RCA. The guiding catheter was advanced over the stent for further support, without success. Withdrawal of the stent into the guide was attempted, resulting in longitudinal compression and partial stripping off of the balloon (Figure 1A). The stent could neither be advanced nor recaptured into the guiding catheter due to severe deformation of the proximal end. 

Under fluoroscopic guidance, the catheter, wire, and stent (still partially affixed to the balloon) were withdrawn en bloc to the right forearm. The stent balloon was removed, leaving the stent on the Prowater wire. Over the Prowater wire, the 6 Fr x 10 cm sheath was exchanged for a 6 Fr x 25 cm Glidesheath, with its tip abutting the stent. A 4 mm Amplatz Gooseneck snare (ev3) was used to grasp the proximal end of the stent, which was withdrawn into the sheath and externalized (Figure 1B). Via the radial sheath, the RCA was reengaged with a 6 Fr AL 0.75 guiding catheter (Cordis Corporation), and the Prowater wire was repositioned in the distal vessel. Two Promus Element stents (4.0 x 16 mm and 4.0 x 20 mm) were deployed in the mid and proximal RCA, in an overlapping fashion. The stents were postdilated with a 4.0 x 12 mm non-compliant balloon at high pressure. Final angiographic result is shown in Figure 1C. 

Discussion. The present report illustrates a snare-removal technique for a severely deformed stent via radial artery approach. Maintaining stent position on the wire in the radial artery facilitated coaxial advancement of the Gooseneck snare and subsequent removal. The larger inner lumen of the 6 Fr Glidesheath (0.087˝) versus the 6 French guide catheter (0.070˝) provided greater clearance for recapture of the compressed proximal end of the stent. Attempting to snare the wire and stent in the aorta without first withdrawing into the radial artery would have been more technically challenging, with potentially higher risk for injuring the coronary arteries and/or dislodging the stent from the wire. Consideration was given to antegrade snaring from the femoral approach, but this would have required a second arterial puncture, with attendant risk of bleeding complications in the fully anticoagulated patient. 

Conclusion. Snare removal of a deformed coronary stent is feasible from a radial artery approach, even during intervention for acute MI. Maintaining stent position on the guidewire and the use of a long sheath obviated the need to use a larger French system from a femoral approach.

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From the Department of  Cardiovascular Medicine, Beaumont Hospitals, Royal Oak, Michigan.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Hanson reports personal fees from Infraredx, outside the submitted work.

Manuscript submitted June 10, 2013, provisional acceptance given June 12, 2013, final version accepted July 25, 2013.

Address for correspondence: Ivan Hanson, MD, 1301 West 13 Mile Road, Royal Oak, MI 48073. Email: Ivan.Hanson@beaumont.edu