The new-generation Silk device may be especially useful for treating aneurysms in the distal vasculature, researchers suggest.
In a small case series, use of a low-profile flow diverter known as the Silk Vista Baby (SVB; Balt Extrusion), appears feasible and technically safe for the treatment of intracranial aneurysms. The results were published online recently, ahead of print in the Journal of NeuroInterventional Surgery.
“The Silk Vista Baby is a welcome addition to the existing treatment options for intracranial aneurysms,” José Manuel Pumar, MD (Hospital Clinico Universitario, Universidad de Santiago de Compostela, Spain), told Neurovascular Exchange.
Commenting on the results, Pumar explained that the most important novel feature of this new flow diverter is its ability to be delivered through a 0.017-inch microcatheter. This enhances both navigability and trackability, increasing the ability to access the distal vasculature. Another important feature of the device, he added, is its 48 drawn filled tubing wires, which match nitinol with a platinum core into a single wire; these facilitate full radiopacity without the need for additional platinum wires. The device received its CE Mark in 2018.
European and Canadian investigators led by Mario Martínez-Galdámez, MD (Hospital Universitario Fundacion Jimenez Diaz, Madrid, Spain), analyzed clinical, procedural, and angiographic data on 43 aneurysms treated with the SVB in 41 consecutive patients (68% women; average age, 50.5 years). Average aneurysm size, classified by maximum diameter, was 9.5 mm (range 2-30 mm). Overall, 34 aneurysms were unruptured. Five were previously ruptured aneurysms that recurred after initial coiling, and two were acutely treated with an SVB after a subarachnoid hemorrhage.
Eleven aneurysms were located in the anterior communicating artery/A1/A2, six in the middle cerebral artery (MCA) bifurcation, five in the M1 segment, four in the pericallosal artery, three in the M2 segment, three in the V4 segment, and 11 elsewhere.
Technical Success and Safety
There were five intraprocedural complications, all of which resolved without clinical consequences, and three postprocedural events. The latter events included a central venous catheter infection requiring antibiotics in the ruptured MCA case, one heavy headache managed with steroids in a 15-mm saccular A1-A2 aneurysm, and one groin pseudoaneurysm that resolved with compression.
The initial occlusion rates were complete occlusion in eight aneurysms, near-complete occlusion in five, incomplete filling in four, and persistent filling in 26. The mRS score at discharge from hospital did not change from the admission mRS score.
“In our opinion, SVB combine the two main advantages of [flow diverters] and low-profile stents in terms of occlusion rate and deliverability, respectively,” Martínez-Galdámez et al write. “Also because of the lower profile of the device, coadjuvant coiling [was] done in 13 cases without friction, without modifications on arterial angulation, and with an average fluoroscopy time of 34 min.”
Pumar agreed that the SVB appears to be “a good tool for the treatment of aneurysms in distal vessels.” He pointed out, however, that this is only a small, retrospective series. Questions still remain as to whether this flow diverter is indeed safe and effective for the treatment of aneurysms located in small vessels, as well as how it will fare with the long-term follow-up. He also noted that two complaints in which the device edge assumed a “fish-mouth” effect have emerged in postmarketing surveillance. The implications of such events remain to be elucidated.
Martínez-Galdámez M, Biondi A, Kalousek V, et al. J NeuroIntervent Surg. 2019;Epub ahead of print.
Martínez-Galdámez and Pumar report no relevant conflicts of interest.