Extraction of fully deployed coronary stents

Unrecoverable stent deformation in the left main: Crush it or remove it?

Serial ostial and distal left main lesions continue to be one of the most difficult tasks for the interventional cardiologist, with many potential complications occurring. We present such a high-risk percutaneous coronary intervention where immediate stent explantation was deemed necessary because the metal deformation and high radial strength of the particular stent platform would prevent an acceptable procedural result if it had been crushed to the vessel wall. The aim of this paper was to discuss left main stent deformation, debate the risks and benefits of stent explantation and finally test in-vitro our theory on "insufficient" crush with stents with high radial strength and compare it with conventional stents. Bench-testing supports our ad-hoc explantation decision showing stent underexpansion, recoil, and malapposition, obtaining an inadequate minimal stent area.

Intentional removal of erroneously deployed coronary stents: A case series and review of the literature

Most reports of stent retrieval involve undeployed, embolized stents. While the retrieval of fully deployed stents has been sporadically reported, most of these were not intentional. The feasibility and safety of intentional retrieval of fully deployed, but erroneously placed stents have not been well described. We report four cases of successful, intentional stent retrieval for stents placed erroneously in an aorto-ostial position. The stents were retrieved at varying times after deployment, ranging from immediately to up to 5 years. In all cases, stents were retrieved successfully with no complication. We conclude that the intentional retrieval of fully deployed, but erroneously placed stents is feasible and safe when stenting involved an aorto-ostial location.

Snare extraction of a fractured coronary stent in a saphenous vein graft

Retrieval of intravascular objects can be accomplished through snare retrieval. We report a case in which a patient presented with symptomatic in-stent restenosis caused by a fractured aorto-ostial sirolimus-eluting stent in a saphenous vein graft. Because of the inability to selectively engage the stent ostium with the guide catheter, the fractured stent was removed with an endovascular snare in order to permit successful revascularization. With the proximal portion of the stent retrieved by the snare, a new stent was implanted without complication.

When size matters: lessons learned from left main stent embolization and retrieval

While the advantages of drug-eluting stents (DES) have been demonstrated in moderate and small-sized vessels, the benefits of DES use in selected larger vessels are increasingly recognized. In the following case presentation, the use of a DES outside the approved vessel diameter to treat left main coronary artery disease led to retrograde migration of the stent over the guiding catheter. Solutions to capturing and retrieving a stent in this position are discussed and our approach to resolving the situation is presented.

Intracoronary fracture and embolization of a coronary angioplasty balloon catheter: retrieval by a simple technique

We report a technique for retrieval of a balloon along with a portion of its shaft from the coronary system using a simple technique that does not involve the use of snare or any other retrieval tool. An additional angioplasty wire and a balloon catheter were used to remove the balloon from the coronary system.

Extraction of previously deployed stent by an entrapped cutting balloon due to the blade fracture

During treatment for in-stent restenosis, entrapment of cutting balloon occurred because of the blade fracture. Removal of the balloon caused stent extraction, inducing acute occlusion of the coronary artery. Application of cutting balloon for in-stent restenosis requires every caution against such type of complications.

Inadvertent stent extraction six months after implantation by an entrapped cutting balloon

We report a case of extraction of a restenosed aorto-ostial stent by an entrapped cutting balloon that had inadvertently been passed through a protruding stent cell. Cathet Cardiovasc Intervent 2001;53:415-419.

Technical considerations when intervening with coronary device catheters in the vicinity of previously deployed stents

As stent use increases, interventional cardiologists are increasingly faced with patients that require procedures in the vicinity of previously deployed stents. We present two cases of side-branch interventions in the vicinity of previously deployed stents where devices were trapped by the stent. In each case, traction on the device resulted in stent dislodgment. The stents were successfully extracted and replaced without complications.

Mechanical behaviour modelling of balloon-expandable stents

Endoprostheses are small struts placed by intravascular way to restore the vascular lumen and flow conditions. The purpose of this work is to provide models for evaluation and characterisation of some mechanical properties of a balloon-expandable stent by using the finite element method. Here we present the results for a metallic tubular peripheral prosthesis: the P308 Palmaz stent. We focus on the mechanisms linked to the structure expansion and its long-term behaviour. Several models are constructed in order to determine the stent shape after dilation and to assess the stress and strain fields in its wall due to this transformation. They inform us about the shortening percentage on expansion, degrees of radial and longitudinal recoil, and weaknesses of the structure. Various methods, differing in their levels of complexity, are then attempted to exhibit the predominant factors responsible for the crushing of a stent under external pressure. Moreover, the sensitivity of this critical pressure to geometric imperfections is studied. Lastly, since this kind of material is implanted for a lifetime, we test the stent with regard to fatigue life. Beyond safety considerations, this type of characterisation provides mechanical properties that are often difficult to obtain by experiments. If it was available for various stents, such information could be used to choose the appropriate prosthesis for specific applications. Moreover, confronted with observations from practitioners, they might lead to a better understanding of the failure or success of a particular design and to work on the product optimisation.

Inadvertent stenting of left main coronary artery complicated by later in-stent restenosis

Stenting of both the protected and unprotected left main coronary artery has been described. This case presents a patient who had inadvertent left main stent deployment. A 47-year-old female presented with a non-Q-wave infarction and subsequent angina leading to angiography and angioplasty of her proximal ramus intermedius artery. Recurrent angina and ECG changes necessitated repeat coronary angiography and angioplasty on the same day with Wiktor stent deployment to treat a resultant dissection. Poststent deployment pictures revealed that the stent had been partially deployed in the left main coronary artery. Additional balloon dilatations were performed at the ostia of the left anterior descending and circumflex arteries through the stent. Three months later the patient presented with progressive angina and was discovered to have severe distal left main stenosis. In a case such as this, stent removal may be preferable to leaving an unnecessary stent within the left main coronary artery. Cathet. Cardiovasc. Intervent. 48:194-197, 1999.

Successful retrieval of a lost coronary stent from the descending aorta using a loop basket intravascular retriever set

Delivery of a balloon-expandable stent was complicated by a systemic embolisation. The radio-opaque stent was lost in the descending aorta, but then removed by using a loop basket intravascular retriever set without any peripheral arterial complication.

Successful management of Palmaz-Schatz stents deformed by inadvertent angioplasty outside the stents

We describe a case in which balloon angioplasty of thrombosed saphenous vein graft stents resulted in compression and deformation of the stents because of inadvertent passage of the guidewire outside the stents. This condition was diagnosed by intravascular ultrasonography, which was then ultimately utilized to direct and optimize placement of additional stents to exclude the deformed stents from the vessel lumen.