Multiplanar CT angiography reconstruction of the left internal carotid artery stenosis in all study patients 

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... to creatinine clearance value until the end of the procedure), (3) atropine 0.5 – 1 mg i.v. before stent postdilation,(4) clonidine 75 – 150 mg i.v. in case of systolic blood pressure >200 mmHg. Brachial hemostasis was obtained with manual compression. Patient population Tables 1 and 2 list the clinical, anatomical, and procedural characteristics of study patients. High-surgical-risk characteristics were present in 10 out of 14 (71%) patients. CAS was successfully accomplished in all but one case (technical success: 92.8%). In this patient (patient #7, Fig. 1), it was impossible to advance a stiff wire inside the diagnostic catheter positioned in the LCCA due to prolapse of the wire-catheter assembly. Interestingly, after several attempts from the brachial approach, the procedure was successfully carried out using the standard femoral approach. In this case, CT angiography showed the narrowest angle (18°) between the IA and the LCCA origin. One patient (patient #13, Figs. 1 and 2) had contraindication for filter use due to unfavorable anatomical characteristics (highly soft, subocclusive plaque with a sharp bend in the ICA distal to the lesion) and underwent successful CAS with a proximal brain protection system (8F MOMA system) (Figs. 4 and 5). In 11 patients, the sheath was withdrawn when the ACT value was <150 s. In the remaining three patients, bivalirudin was used instead of heparin and the sheath was removed 30 min after the end of drug infusion. Hemostasis was achieved with manual compression without vascular complications in all patients. Clinical success was obtained in all but one patient (92.8%) who developed a visual defect soon after the procedure, likely due to retinal embolism. No in- hospital or 30-day cardiac or cerebral major adverse events (i.e., death, major/minor stroke, AMI) occurred. In the bovine aortic arch variant in which the LCCA has its origin distal to the IA, the major anatomic constraint is the double tight turn between the arch and the IA and between this vessel and the LCCA. The coexistence of other unfavorable complex anatomies, such as type II-III aortic arch configuration, LCCA tortuosity, and distal LICA kinking, may increase procedural difficulties and complications during CAS especially when the standard femoral approach is used. In fact, it may be difficult to obtain enough support to advance a wire into the external carotid artery and a guide or an introducer sheath into the distal LCCA. In case of failure, one option is to position the guide at the LCCA ostium and carry out the procedure from that point. With this technique, a second wire in the external carotid artery is often required to stabilize the guide. However, the presence of other complexities requiring additional guide support, such as LCCA tortuosity (Fig. 1, case #3, 10, 14) or calcification of the carotid bifurcation (Fig. 2, case #1, 8), may result in prolapse of the system into the aortic arch and CAS failure. With the right brachial approach, three major turns are found on the way to the left carotid bifurcation. The first is at the point where the right subclavian artery joins the IA, the second between the IA and LCCA, and the third where the LCCA turns upward and anteriorly towards its usual distribution territory (Fig. 6). Each of these bends may cause friction and resistance to CAS equipment passage. The most critical turn is between the IA and the LCCA. The more distal the LCCA takes off from the IA, the broader the angle is — an anatomical condition that was found, in our series, to be associated with high procedural success rate using the brachial access route. In our patients, “ high surgical risk ” features were present in almost 70% of cases combined with “ high endovascular risk ” characteristics (i.e., bovine aortic arch configuration, LCCA tortuosity, lesion calcification, etc.) in all. Despite this, technical and clinical success was achieved in 13 out of 14 patients (92.8%). Interestingly, the only patient in whom we failed to advance the guide to the distal LCCA had a common origin of the IA and the LCCA and the narrowest angle (18°) between the two vessels. Unexpect- edly, this patient underwent CAS from the femoral approach easily and without complications. Thus, CAS approach should be chosen according to the bovine arch anatomy as shown by CT angiography. Femoral approach may be attempted first in case both the LCCA and IA have a common origin from the aortic arch and a sharp angle (<50°) between these two vessels is present. On the other hand, the brachial approach may be preferred in cases with a wider angle (as in patients #2 and #9), unfavorable aortic arch configuration (type II-III), and/or severely diseased aortic arch that may increase the risk of embolization during catheter manipulation. A systematic brachial approach may be the first choice in those cases in which the LCCA takes off directly from the IA. In very complex anatomies, a direct transcervical access to the common carotid artery, either percutaneously or through a small incision, has been proved to be a feasible, alternative strategy [4]. Although the small size of the brachial artery (average diameter 3 mm) may be a limitation of this technique, we demonstrated the feasibility of using a large (8Fr) proximal cerebral protection device with this approach in patients who had carotid lesion characteristics associated with high complication risk. Indeed, attempts to cross this type of lesion with filters, unprotected predilation in case of filter crossing failure, and suboptimal filter positioning may be associated with cerebral embolization. These are the conditions in which proximal protection may represent a valid alternative because all the procedural steps, including wire crossing of the lesion, are carried out under the flow reversal protection. The MOMA system was easily positioned below the carotid bifurcation, and CAS was carried out successfully with no cerebral or local complications. Although the safety and efficacy of the MOMA system have been reported in previous studies [5], to our knowledge, there is no previous report of the use of this device from the brachial route. In our patients, the sheath was removed when the ACT value was <150 s and hemostasis was obtained by manual compression. In patients with a small brachial artery and poor run-off, the thrombin inhibitor bivalirudin may be a valid alternative to unfractionated heparin. This drug has a reversal of the anticoagulation effect that is faster (~30 min) than heparin, allowing an earlier sheath removal with a reduced risk of puncture-site complications. Finally, among the available imaging techniques, CT angiography allows a complete visualization of the anatomical characteristics of the aortic arch, arch branches, carotid bifurcation, and distal ICA as well as intracranial circulation. This diagnostic work-up may help to determine which patients are best suited for a radial approach simplifying the procedure, reducing the risk of complications, and increasing the success rate of ...