Stent fracture in malignant biliary obstruction

Coronary Stent Fracture

Coronary stent fracture is a relatively uncommon and rare complication of stent implantation. The reported incidence of stent fracture among drug-eluting stents ranges from 1% to 8%. Since 2003, when the use of drug-eluding stents was approved by the FDA for the treatment of coronary atherosclerosis, a number of retrospective and prospective studies and case reports have been published. We reviewed these publications to determine the incidence, predictors, clinical implications, and different management strategies for drug-eluding stent fracture in the coronary arteries. A review of the literature showed that the risk for stent fracture was higher with right coronary artery location, increased vessel tortuosity and angulation prior to stenting, use of overlapping stents, and use of longer stents. A higher risk of bare metal stent fracture was reported in saphenous vein bypass grafts. The authors also report in this issue in the Department “Case Study” a symptomatic fracture of a sirolimus-eluding Cypher® stent in the mid-left anterior descending artery.

Detection of stent fractures: a comparison of 64-slice CT, conventional cine-angiography, and intravascular ultrasonography

RATIONAL AND OBJECTIVES

We evaluated the ability of 64-slice computed tomography (CT), conventional cine-angiography, and intravascular ultrasound (IVUS) to detect stent fractures under ideal conditions. Coronary stent fracture has been implicated as one of the mechanisms of stent thrombosis and, perhaps, in-stent restenosis. However, the preferred imaging modality in detecting fractures in coronary stents has not been well established.

MATERIALS AND METHODS

Four different types of commonly used coronary stents (Cypher, Taxus, Vision, Hepacoat) each with three strut fractures (Cypher, 5; Taxus, 5; Vision, 4; Hepacoat, 5) were nominally deployed in polyurethane tubes and imaged with 64-slice CT, conventional cine-angiography, and IVUS. For each stent type, an unfractured control stent was also imaged.

RESULTS

Overall accuracy (84.1% vs. 73.9%), sensitivity (80.7 vs. 77.2%), and specificity (100% vs. 58.3%) for stent fracture detection was higher with 64 multislice CT compared to conventional cine-angiography. Stent fractures were not accurately detected by IVUS. Fracture detection by multislice CT was best when the stents were imaged at 45 degrees to the z-axis.

CONCLUSIONS

Under ideal in vitro conditions, CT has a high accuracy when used to evaluate coronary stent fractures. The overall accuracy, sensitivity, and specificity of detecting stent fractures are lower by conventional cine-angiography. Stent fractures were not detected using IVUS.

Fracture of a Nitinol Carotid Artery Stent That Caused Restenosis

The placement of self-expanding nitinol stents in the carotid artery is rapidly emerging as a minimally invasive alternative in the treatment of cervical carotid artery occlusive disease. Fractures of balloon-expandable stents after placement in the carotid artery have been previously documented. The authors report on a single case of early stent fracture and complete mid-body disruption of a self-expanding stent associated with a significant restenosis necessitating repeat intervention after carotid artery stent placement for a de novo atherosclerotic lesion.

Coronary artery stent fracture

Coronary stent fracture is a rare but potentially serious complication of coronary artery stenting. In light of the non-specific presentation of stent fracture, it is also an easily missed complication. In order to ensure rapid recognition and treatment of this entity, physicians must be aware of its existence and its possibility under the right circumstances. We present the case of a 61-year-old Guyanese male who presented with unstable angina secondary to a stent fracture within two weeks of elective percutaneous coronary intervention (PCI) for in-stent restenosis.

A case of popliteal stent fracture with pseudoaneurysm formation

We describe a case of angiographically documented stent fracture and pseudoaneurysm formation in a patient with femoropopliteal disease, which was successfully treated with deployment of an endovascular stent graft. Technical aspects of the procedure are discussed and the experience with stent fractures previously reported in the literature is reviewed.