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Background The Enterprise (EN) vascular reconstruction device is a self-expanding nitinol stent used as adjunctive support in wide-necked aneurysm coiling. We sought to evaluate the effect of deployment technique on how well the EN stent conforms to the vessel wall around a curve. Methods A flow model consisting of a 3.5 mm diameter silicone tube forming a 7 mm radius curve was visualized using high-resolution flat-panel CT (FPCT; DynaCT). EN stents (4.5 mm×22 mm) were deployed using three methods: (1) microcatheter pull-back, (2) delivery microwire push and (3) a combination of both methods so as to keep the microcatheter tip centered within the lumen during deployment. FPCT images were visualized using multiplanar reconstruction for evidence of incomplete stent apposition (ISA). Results FPCT revealed a critical role for deployment method in stent–wall apposition as noted by the development of a crescent-shaped gap between the stent and the wall. Specifically, the manufacturer-recommended microcatheter pull-back unsheathing technique (method 1) resulted in outer curve ISA, while the microwire push technique (method 2) led to inner curve ISA. Using method 3 in a dynamic push–pull manner minimized both inner and outer curve ISA. Conclusion The deployment method used to deliver the EN vascular reconstruction device plays a critical role in determining how well its struts appose the vessel wall in vitro. This characteristic must be taken into account when deploying this flexible low-profile stent to avoid ISA in even mildly tortuous anatomy given the possible link between stent malapposition and thromboembolic complications.

Objective The gold standard for the diagnosis of intracranial atherosclerosis remains catheter based digital subtraction angiography (DSA). A symptomatic hemodynamically non-significant intracranial atherosclerotic lesion is described, whose underlying embologenic characteristics were not detectable by either DSA or three-dimensional rotational angiography (3DRA) but fully realized by C-arm cone beam CT (CBCT) angiography. Clinical presentation A 73-year-old man presented with crescendo transient ischemic attacks consisting of right arm tingling and hand weakness despite long term dual antiplatelet therapy with aspirin and clopidogrel for coronary artery stent. DSA and 3DRA demonstrated a smooth benign appearing left cavernous internal carotid stenosis of Intervention Given the incongruence of the lesion with the patient9s symptoms and lack of response to aggressive medical treatment, a decision was made to obtain higher resolution imaging. CBCT angiography was obtained with injection at two contrast dilutions, which uncovered an underlying ruptured ulcerated calcific plaque with a small dissective component and overlying thrombus. The lesion was treated with anticoagulation followed by balloon mounted stent angioplasty, with symptom resolution and maintained patency at the 1 year follow-up. Conclusion The superior spatial resolution and dynamic range characteristics of CBCT angiography provide added clinical utility in disambiguation of questionable intracranial atherosclerotic lesions which may be missed by conventional planar and rotational angiography. The additional information provided by CBCT angiography could be useful in lesion risk stratification and help refine indications for intracranial stent angioplasty given its recent documented shortcomings vis a vis medical management.

Objective Although intracranial stents have expanded the spectrum of aneurysms amenable to coiling, closed cell design variants can be prone to incomplete stent apposition around tightly curved arterial bends. A case is presented illustrating the technical ramifications of this phenomenon during subsequent treatment. Clinical presentation A 49-year-old woman who had previously undergone Enterprise (closed cell design) stent mediated coiling of a wide necked ophthalmic carotid artery aneurysm was noted to harbor residual central filling on follow-up imaging, and was scheduled for additional embolization. Intervention During retreatment, performed with a second concentrically placed Enterprise and further coil packing using the jailing technique, the proximal portion of the second Enterprise stent failed to expand as expected. C-arm cone beam CT (CBCT) revealed the second stent to have been navigated into and out of the orphaned lumen created by the incompletely apposed first Enterprise stent at the carotid siphon. This stent entanglement resulted in the formation of a trapped proximal double-barrel lumen in the curved segment and resolution to a single barrel lumen in the distal straight segment of the parent vessel facing the aneurysm neck. Conclusion Caution is urged when navigating around curved vessel segments through previously deployed intracranial stents, which may be incompletely apposed to the vessel wall, to avoid deleterious and potentially catastrophic entanglement. CBCT imaging may be helpful in delineating the spatial relationship of previously deployed intracranial stents during subsequent endovascular navigation.