Flow diversion in challenging vascular anatomies: the use of low profile stent retrievers for safe and accurate positioning of the microcatheter

Abstract

Background: Hemodynamic therapy with Flow-Diverters has become a fundamental option for treatment of cerebral aneurysms. A major obstacle of Flow-Diverters is the comparatively stiff microcatheter required for implantation. Consequentially, maneuverability is limited and primary catheterization of peripheral targets may be difficult or even futile in challenging vascular anatomies. To overcome this, a highly navigable microcatheter must be used to attain the desired vascular segment, followed by a hardly controllable exchange-maneuver via a long microwire, involving a high risk for wire-perforation. Our study aimed to investigate the value of low-profile stentretrievers as a railway for introduction of the required microcatheter, which allows to maintain a stable endovascular position and reduce the risk for procedural vessel injury. Methods: 14cases (8females, mean-age 59y) of Flow-Diverter-Implantation requiring the use of a low-profile stentretriever were reviewed. All cases featured a challenging vascular anatomy. After micro-catheterization of the desired segment, the stent-retriever was carefully deployed as an anchor in a secure, distal location. In all cases a pREset/LITE-stent-retriever was used for introduction of the equipment required for implantation. Results: In all cases the anchoring-maneuver was performed without technical complications. The stent-retrievers maintained a stable position after deployment in all situations. No potential traumatic sudden movements of the microcatheter occurred. No procedure-related perforations, dissections or vasospasms were observable during the interventions or their aftermath. Conclusions: In our experience the stent-retriever-anchoring-maneuver represents a potentially essential and safe amendment for flow diverter treatment in technically challenging situations.

Single-Center Experience With the Bare p48MW Low-Profile Flow Diverter and Its Hydrophilically Covered Version for Treatment of Bifurcation Aneurysms in Distal Segments of the Anterior and Posterior Circulation

“…This way, the Prowler Select Plus could be navigated to an otherwise unachievable endovascular position for p48MW delivery. An illustrated step-by-step protocol of the cast-PRESET maneuver was published recently and provides a detailed video of the technique (22).…”

A revised stent-retriever anchor technique to obtain the distal access through a large or giant aneurysm

“…As previously reported, there may be concerns about placing a stent-retriever in a healthy artery which can cause dissection or vasospasm [7] . To prevent this possible complication, our suggestion is to position the stent in the M1 segment for the anterior circulation and the P2 segment for the posterior circulation, avoiding the deployment of the stent into more distal and smaller branches that are definitely more fragile.…”

“…Different anchor techniques can be used to straighten the microcatheter. Many techniques have previously been described to address this problem, such as the "balloon", "stent", "Solitaire", and "sea anchor" techniques [4][5][6][7] .…”

“…Parry et al [7] described the Solitaire (Medtronic) salvage technique, which allowed the successful reduction of the looped catheter within the aneurysm in three cases. In all cases, once the reduction maneuver was completed, the Solitaire was re-sheathed and the microcatheter was exchanged using an exchange microwire [7] .…”

“…However, we assume that the greater length of the Aperio® stent-retriever compared to the pREset LITE® stent-retriever (30 mm vs. 20 mm) could theoretically guarantee a more stable distal anchorage during the several maneuvers. The anchor technique presents two additional advantages compared to the Solitaire salvage technique used by Parry et al [7] . Firstly, the use of a smaller microcatheter allows an easier and safer intra-aneurismal navigation, reducing stress force on the aneurysm walls.…”