A Rare Complication of Carotid Artery Stenting: Displacement of Marker Ring Causing Locking of Stent and Incomplete Stent Expansion

Abstract

SUMMARY: We present a rare case of a complication of placement of a carotid artery stent represented by partial opening of a carotid Wallstent caused by displacement of its metal ring marker, which thus hindered complete expansion of the stent. An intraluminally locked carotid stent necessitated referral of the patient for urgent carotid endarterectomy. A possible reason of this unusual complication can be a manufacturing defect, which, to our knowledge, was not documented previously in open public data bases or on the Internet. Carotid artery stent (CAS) placement is a well-established method for revascularization of the obstructed lumen in patients with carotid artery disease. Complications may occur during the procedure and generally are presented by neurologic symptoms as a result of microembolism or thrombosis, which can be prevented by the use of a protective filter. Less common complications during CAS placement are hemodynamic conditions such as bradycardia and hypotension, which are easily treatable.1-3 Mechanical complications such as spasm or dissection are seen less and less frequently with personal experience and innovations in equipment. Complications caused by unlucky mechanical accidents during stent implantation such as incomplete opening are unusual and therefore can be a reason for unpredictable outcomes of CAS placement. We present a rare case of a CAS complication with incomplete opening of a carotid Wallstent (Boston Scientific, Natick, Mass) caused by displacement of its metal ring marker, which hindered the complete expansion of the stent and required urgent surgical intervention. Case ReportA 71-year-old woman with a history of transient ischemic attack and right internal carotid artery stenosis of more than 70% in the proximal portion previously diagnosed on CT and MR angiography was referred to our hospital for implantation of a carotid stent. CAS with a carotid Wallstent Monorail 4 with a cerebral protection filter (EPI Filter Wire; Boston Scientific) was planned. The patient had received therapy with antiaggregant medications: aspirin 100 mg/day and clopidogrel 75 mg/day for 1 week before stent implantation. A 6F shuttle introducer was placed into the right common carotid artery by the femoral approach, and preprocedure control angiograms were obtained. A cerebral protection filter was placed distally to the obstructed internal carotid artery, and then self-expandable Wallstent (7 ϫ 50 mm) deployment was performed. During deployment, unexpected slipping of the distal ring of the metal marker over the shaft of the stent was observed. The slipped ring at one fourth of the proximal end of the stent hindered the complete expansion of the stent. The shaft of the stent and the protection filter could not be pulled back because the metal ring locked over the stent (Fig 1). Attempts to rescue the fixed stent and slipped metal ring were unsuccessful, and the patient was rushed to the operating room. During endarterectomy, the stent, stent shaft, and protection filter were removed without any ...

Cerebral Air Embolism and Vasospasm after Carotid Revascularization: A Case Report

“…A large pseudoaneurysm was found in the cervical ICA due to carotid wall injury caused by the guiding catheter during the procedures [5]. Partial opening of a carotid Wallstent was caused by displacement of its metal ring marker, which thus hindered complete expansion of the stent [6]. A carotid stent was not expanded due to a detached stent sheath [7].…”

Locking between a Cerebral Protection Device and a Stent-Delivering Catheter during Carotid Artery Stenting

“…Several reports on the mechanical complications related to CPD have emphasized the importance of careful consideration of both the patient's anatomy and the devices' construction and dimensions ( Table 1). The locking between the CPD and other devices may have serious consequences, with immediate surgical removal being essential 1,5,6,13 . With the exception of partial opening of the stent by slippage of the metal ring marker 6 , these consequences arise from insufficient observation of the marker position or a deficient understanding of marker dimensions.…”

“…The locking between the CPD and other devices may have serious consequences, with immediate surgical removal being essential 1,5,6,13 . With the exception of partial opening of the stent by slippage of the metal ring marker 6 , these consequences arise from insufficient observation of the marker position or a deficient understanding of marker dimensions. This can be prevented by careful observation of the patient's anatomy and the markers visible in fluoroscopy.…”

“…The most disastrous situation might be separation of the membranous component from the CPD [13][14][15] . In this context, most of the mechanical complications related to CPD necessitate surgical removal 1,5,6,13 ; only a case of a fused balloon and CPD has been rescued endovascularly 7 . In the present case, surgical removal of the device was considered the last resort.…”

“…However, the CPD itself may cause fatal complications, with mechanical or iatrogenic sequelae occurring with an incidence of 0.9% (4/442) 1,3,4 . In addition to sequelae such as vascular spasm or dissection, some unpredictable mechanical accidents -such as locking between devices or incomplete stent expansion -may result in catastrophic outcomes requiring surgical removal of the locked devices [5][6][7] . Moreover, permanent locking between devices would be catastrophic, which has prompted consideration of CAS without the use of a CPD in order to prevent this possibility [8][9][10] .…”