In the early 1990’s, endovascular treatment using embolic coils for the treatment of intracranial aneurysms was established. Since then, there has been a significant body of peer-reviewed literature written by medical experts regarding the use, safety, and efficacy of these detachable embolic coils. With the publishing of the ISAT (Intracranial Subarachnoid Aneurysm Trial) trial data in 2005, which compared clinical outcomes of neurosurgical clipping and endovascular coiling, embolic coiling became the preferred method for treatment of the majority of unruptured intracranial aneurysms [ISAT 2003, Molyneux et al. 2005].
Since then, there has been a revolution in interventional neuroradiology which includes a shift toward catheter based procedures. Unfortunately, for a variety of reasons there are not always endovascular treatment options available to some patients with intracranial aneurysms, especially if the neck of the aneurysm is wide. Additionally there is a range of concerns relating to patient comorbidities, aneurysm geometry or the location of the lesion. Consequently there are many challenges, even today, when treating patients with such lesions. Hence there has been significant research in this arena to develop adjunctive devices to be used with embolic coils as well as sole therapy devices.
The PulseRider has an open cell frame. The unique frame configuration opens to conform to the vessel walls. The PulseRider is specifically designed to resolve the shortcomings of current endovascular devices by preserving luminal patency and hemodynamic flow through the parent vessel bifurcation, while minimizing exposed metal in order to encourage early endothelialization while securely retaining embolic agents within the aneurysm sac. The PulseRider is delivered through commercially available microcatheters using standard endovascular techniques. The implant is retrievable and may be repositioned by retracting it into the microcatheter at any time during or after deployment (prior to detachment). The implant is designed with an open frame to maintain luminal patency. It is deployed at the parent vessel bifurcation and across the aneurysm neck to provide a support framework, bridging the aneurysm neck while retaining embolic agents within the aneurysm. The PulseRider is electrolytically detached from the delivery wire.
In the early experience with the Pulse Rider device its use was safe and effective as an adjunct in the treatment of bifurcation aneurysms arising at the basilar apex or carotid terminus 1).
The safety and probable benefit of the PulseRider (Pulsar Vascular, Los Gatos, California) for the treatment of broad-necked, bifurcation aneurysms was studied in the context of the prospective, nonrandomized, single arm clinical trial-the Adjunctive Neurovascular Support of Wide-neck aneurysm Embolization and Reconstruction (ANSWER) Trial.
Aneurysms treated with the PulseRider device among sites enrolling in the ANSWER trial were prospectively studied and the results are summarized. Aneurysms arising at either the carotid terminus or basilar apex that were relatively broad necked were considered candidates for inclusion into the ANSWER study.
Thirty-four patients were enrolled (29 female and 5 male) with a mean age of 60.9 years (27 basilar apex and 7 carotid terminus). Mean aneurysm height ranged from 2.4 to 15.9 mm with a mean neck size of 5.2 mm (range 2.3-11.6 mm). In all patients, the device was delivered and deployed. Immediate Raymond I or II occlusion was achieved in 82.4% and progressed to 87.9% at 6-month follow-up. A modified Rankin Score of 2 or less was seen in 94% of patients at 6 months.
The results from the ANSWER trial demonstrate that the PulseRider device is safe and offers probable benefit as for the treatment of bifurcation aneurysms arising at the basilar apex or carotid terminus. As such, it represents a useful addition to the armamentarium of the neuroendovascular specialist 2).