Defining the optimal size of an aspiration catheter in relation to the arterial diameter during mechanical thrombectomy for stroke.

BACKGROUND: Mechanical thrombectomy for acute ischemic stroke is effective and includes different technical approaches. Operators use direct aspiration, a stent retriever, or a combination of both. Direct aspiration can be performed with various catheters of different sizes depending on the diameter of the occluded vessel. PURPOSE: We studied the relationship between the catheter diameter in regards to the occluded vessel diameter and the rate of successful recanalization. MATERIALS AND METHODS: We conducted a retrospective, monocentric study on a series of consecutive patients treated with mechanical thrombectomy. For each procedure, we extracted each attempt that used direct aspiration and rated the attempt as successful or unsuccessful. We also measured the occluded artery diameter and calculated the ratio between the occluded artery and the aspiration catheter diameters. We tested the association between the diameter ratio and the recanalization status. We also performed inter-rater agreement for the arterial diameter measurement between three interventional neuroradiologists. RESULTS: We included 119 patients with 201 attempts of direct aspiration. A higher diameter ratio was associated with a higher recanalization rate. The analysis in terciles showed that the odds of success were 4.80 higher when the ratio was >0.71 vs <0.54 (p < 0.01). Inter-rater agreement showed near-perfect intraclass correlation with 0.93 (0.91-0.94) consistency and 0.92 (0.90-0.94) absolute agreement. CONCLUSIONS: We demonstrated an association between higher recanalization and a diameter of ratio >0.71 between the aspiration catheter and the occluded artery. These results could guide intraoperative decisions regarding the appropriate selection of aspiration catheters during mechanical thrombectomy increasing the rate of successful recanalisation. A larger study could provide additional data to further specify the optimal ratio.

Embryology of the vertebral artery and variants of the adult.

The vertebral arteries represent in the adult the main blood supply of the posterior cranial fossa, even if they appear relatively late during the embryological life. We reviewed all the most important steps of the vertebral artery's embryological development and the most common variants that can occur in the adult. The aim of this review is to summarize the main events of the development of this artery and to give an embryological explication for the most common variants of this artery.

How to use the Contour intrasaccular device: two illustrative cases.

Contour (Stryker, Kalamazoo, MI) is a relatively new endosaccular device for the treatment of intracranial aneurysms.1 2 Its unique cup-like shape permits treatment of most lesions, including wide-necked, irregular, and shallowed-shaped aneurysms. The sizing of the device only requires two parameters: neck size and equatorial plane (width). It must be positioned at the neck of the aneurysm with the device proximal marker in the parent artery. In our experience, dual antiplatelet therapy is usually not required for intrasaccular devices and this is also an advantage of the Contour device. We report two illustrative cases of wide-neck aneurysms in the anterior and posterior circulation, respectively (video 1). In this video we demonstrate the feasibility of this treatment in a middle cerebral artery bifurcation with atypical triangular shape and typical tip-basilar aneurysm. neurintsurg;16/3/225/V1F1V1Video 1 .

Middle column Stent-screw Assisted Internal Fixation (SAIF): a modified minimally-invasive approach to rescue vertebral middle column re-fractures.

BACKGROUND: There is limited literature regarding the re-fracture of a previously augmented vertebral compression fracture (VCF). These re-fractures may present as an asymptomatic remodeling of the vertebral body around the cement cast while in other cases they involve the middle column, at the transition zone between the cement-augmented and non-augmented vertebral body. In the latter, a posterior wall retropulsion is possible and, if left untreated, might progress to vertebral body splitting, central canal stenosis, and kyphotic deformity. There is no consensus regarding the best treatment for these re-fractures. There are cases in which a repeated augmentation relieves the pain, but this is considered an undertreatment in cases with middle column involvement, posterior wall retropulsion, and kyphosis. METHODS: We report four cases of re-fracture with middle column collapse of a previously augmented VCF, treated with the stent-screw assisted internal fixation (SAIF) technique. A modified more postero-medial deployment of the anterior metallic implants was applied, to target the middle column fracture. This modified SAIF allowed the reduction and stabilization of the middle column collapse as well as the partial correction of the posterior wall retropulsion and kyphosis. RESULTS: Complete relief of back pain with stable clinical and radiographic findings at follow-up was obtained in all cases. CONCLUSIONS: In selected cases, the middle column SAIF technique is safe and effective for the treatment of the re-fracture with middle column collapse of a previously cement-augmented VCF. This technique requires precision in trocar placement and could represent a useful addition to the technical armamentarium for VCF treatment.

Woven EndoBridge Device immediate post-detachment tilt with later displacement: Case report, rescue techniques, and review of the literature.

The Woven EndoBridge Device (WEB) is efficient and safe in the treatment of wide-neck bifurcation intracranial aneurysms. A crucial step in operative planning is establishing the appropriate dimension of the device, and there are limitations to the therapeutic solutions provided by WEBs. We describe a case of a right middle cerebral artery bifurcation wide-neck aneurysm treated with WEB. After the initial deployment of a WEB proven oversized, we substituted it with a smaller one that presented immediate post-detachment intra-aneurysmal tilt probably resulting from undersizing. The 24-h angiographic control identified a partial displacement of the device in the superior middle cerebral artery branch. We describe rescue techniques with review of the literature and our treatment strategy, including effort to reposition the device followed by stent deployment. The treatment was electively completed by the coil-through technique. The post-detachment WEB tilt should be considered an unstable position and treated either by removal of the device or with adjunctive implants. Each WEB size adapts to a range of aneurysmal height and width. This range is not always the same for each specific WEB dimension, based on the table provided by the manufacturer. This eventually predisposes to a different behavior of different WEB sizes regarding the modification of the device's height in relation to the modification of the diameter after deployment.