Embolized Stent in the Coronary Circulation “Without Riding the Wire” and its Novel Management Strategy
- Volume 21 - Issue 10 - October, 2009
- Posted on: 10/13/09
- 0 Comments
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From the Department of Cardiology, National Institute of Cardiovascular Diseases, Dhaka, Bangladesh.
The authors report no conflicts of interest regarding the content herein.
Manuscript submitted February 24, 2009, provisional acceptance given May 11, 209 and final version accepted May 28, 2009.
Address for correspondence: Prof. Afzalur Rahman, MD, PhD, Head of the Department, Department of Cardiology, Sir Salimullah Medical College & Mitford Hospital, Dhaka 1000, Bangladesh. E-mail: firstname.lastname@example.org
ABSTRACT: We report a unique technique for retrieval of a coronary stent, embolized during percutaneous coronary intervention (PCI), using conventional angioplasty wires and angioplasty balloon catheters. In this case, the stent embolized into the distal left main and proximal left circumflex arteries. As the guide catheter and percutaneous coronary angioplasty (PTCA) wire were withdrawn from the coronary arteries, the stent was freely floating in the coronary circulation “without riding the wire”. It was managed by re-entry of the Intermediate PTCA wire through the stent with the help of an over-the-wire balloon and was successfully deployed across the lesion. Stent embolization, although a very rare event, may lead to devastating consequences. This technique has been demonstrated for the first time and employs readily available tools that are familiar to all operators.
J INVASIVE CARDIOL 2009;21:E201–E203
Stents are currently utilized in the majority of percutaneous coronary interventions (PCIs) because they improve angiographic outcomes and decrease rates of angiographic restenosis and repeat revascularization. A rare but potentially serious and challenging complication of coronary stenting is stent loss, which can result in systemic or coronary embolization, emergency coronary artery bypass graft surgery or even death. Manual mounting of stents (which used to be practiced in past) was associated with a significantly higher risk of stent embolization. Besides this, inadequate predilatation, calcified lesions and tortuous lesions increase the chances of stent embolization. Different methods for nonsurgical stent retrieval have been suggested.1–3 Snare devices are commonly used to retrieve the stent. Here we report a case where the stent embolized “without riding the wire” was managed by using a conventional percutaneous transluminal coronary angioplasty (PTCA) wire and angioplasty balloon catheter.
Case Report. A 42 year-old male smoker who was dyslipidemic, nondiabetic, normotensive, of a low socioeconomic background and had a family history of coronary artery disease, was admitted with a history of chest pain of 4 days’ duration. Due to his late presentation, the patient was not undergo thrombolysis. The patient was being treated with low-molecular-weight heparin, aspirin, clopidogrel, beta-blockers, nitrates and a statin. Electrocardiography (ECG) revealed Q-waves in leads II, III and aVF. Echocardiography showed inferior-wall hypokinesia with a global ejection fraction (EF) of 45%. Elective coronary angiography revealed total occlusion of the mid-left circumflex artery (LCX) and a normal left main coronary artery (LM), left anterior descending artery (LAD) and right coronary artery (RCA), and was scheduled for PCI (Figure 1). During PCI, a 2.5 x 17 mm bare-metal stent was stripped from the balloon catheter and was stranded in the coronary artery. The first author, A.R., was then called into the catheterization laboratory. It was determined that the guide catheter along the PTCA wire and the balloon were already withdrawn, leaving the unexpanded stent in a free-floating state in the coronary circulation into the distal left main (LM) and the proximal LCX (Figure 2). A 3.5 mm (6 French) guide catheter was again engaged in the LM coronary artery. An attempt was made to introduce a 0.014 inch extra-support PTCA guidewire through the embolized stent, but this failed. The same PTCA guidewire was again introduced into the distal LCX across the lesion by the side of the stent. The lesion was dilated with a 1.5 x 15 mm balloon, after which we used a 2.5 x 20 mm over-the- wire balloon and a 0.014 inch intermediate wire, and slightly bent the tip. Then the PTCA wire, along with the balloon, were introduced into the LM artery close to the stent, and applying utmost care with over-the-wire balloon support, the PTCA wire was introduced through the stent. Then, with the balloon, we pushed the embolized stent from the LM and the proximal LCX into the lesion at the middle segment of the LCX (Figure 3). Roadmapping was used to carefully determine the exact position of the embolized stent in the LCX. The over-the-wire balloon was then removed, and a 1.5 x 20 mm low-profile monorail balloon catheter was very carefully introduced into the stent. The stent was then deployed across the lesion at 20 atm (Figure 4). Next, the embolized stent balloon was introduced across the stent, and the stent was further expanded at 16 atm. The embolized stent was precisely deployed across the lesion without any significant residual narrowing, but a linear dissection was found distal to the stent. Another bare-metal stent was deployed to cover the distal dissection. The final angiogram showed a good result with TIMI 3 flow in the distal LCX (Figure 5). The patient’s post-procedure course was uneventful, with no ECG or CK-MB changes. The patient was symptom-free and was discharged after 72 hours.
Discussion. Dislodgement of coronary stents before deployment is a rare but challenging complication of coronary stenting. The incidence of stent loss is between 0.6–1.6%.1–3 Different nonsurgical approaches have been proposed for the removal of stents from the coronary circulation.4–16 Preferred procedures vary from laboratory to laboratory. The procedures include: a) retrieval by (i) 1.5 mm low-profile angioplasty balloon catheters, (ii) double (twisted) guidewires, (iii) a self-assembled loop made of a second guidewire, (iv) myocardial biopsy (biliary or bioptome) forceps catheters or a gooseneck/standard (large loop) snare catheters and multipurpose baskets; b) If retrieval of a lost stent appears challenging, crushing/compressing of stents against the vessel wall by another stent (overlying stent deployment) may be an alternative. If all retrieval efforts fail and crushing or deployment is not desirable, then surgical removal could be performed, which has a high risk of mortality and morbidity. In this case, the options included crushing of the stent or emergency coronary artery bypass graft (CABG) surgery. Crushing the stent would have been very hazardous at the particular location of the stranded stent, thus we explored the possibility of using conventional tools like a PTCA wire, over-the-wire and monorail balloons. The challenge here was the reintroduction of the PTCA wire, which may not have readily passed through the unexpanded stent and may have passed by the side of the stent or come out through the strut. Using over-the-wire balloon catheter, as demonstrated here, gives unique support to appropriately negotiate the wire through the stent and thus overcome the challenge. An over-the-wire balloon may provide better support for trackability of the PTCA wire than a monorail balloon through the stent lumen in such situations. An over-the-wire balloon should be in close proximity to the stent to facilitate crossing of the wire through the floating stent lumen. In the event of an unexpanded, floating stent, since the lumen remains narrow, if the tip is bent a little more, it can then go in between the stent struts. The wire should also be introduced very carefully and slowly under continuous fluoroscopic guidance. Regarding the type of balloon, a 1.5 mm over-the-wire balloon would have been a better choice due to its reported outstanding crossability and excellent trackability. But in our case, we used a low-profile 1.5 mm monorail balloon for crossing and deployment of the floating stent across the lesion.
Conclusion. In conclusion, although a free-floating embolized stent in the coronary circulation during PCI is a technically challenging problem, it can be managed by angioplasty balloon catheters and a conventional PTCA wire. To the best of our knowledge, ours is the first report of this novel management technique using readily available tools that are familiar to all operators.