Springfield, Mass. – September 25, 2026 -- Baystate Health has become the first hospital in the United States to enroll patients in the PIONEER trial, a national study evaluating Balt Corporation's Silk Vista Baby flow-diverting stent for unruptured brain aneurysms in small blood vessels, treating its first three patients within days of receiving approval.
Baystate enrolls first three U.S. patients in national aneurysm device trial
The PIONEER study is a prospective, multicenter, single-arm trial spanning 35 leading centers in the United States and 5 in Canada, designed to assess the safety and efficacy of the Silk Vista Baby device. Balt Corporation launched the trial to satisfy FDA requirements for broader U.S. market access after the device received full approval from the Centers for Medicare & Medicaid Services following a prolonged review process.
Device targets vessels as small as 1.5 mm, a gap in current U.S. treatment options
Silk Vista Baby is engineered for blood vessels measuring 1.5 to 3 mm in diameter, addressing aneurysms located along small, distal vessels. The device has been commercially available internationally for several years but has lacked wide U.S. availability. No flow-diverting stent is currently approved in the United States for aneurysms in these smaller vessels, leaving a treatment gap for physicians managing high-risk cases.
Prior access required lengthy humanitarian exemption process, delaying care by weeks
Before trial enrollment, U.S. physicians seeking to use Silk Vista Baby had to apply for a humanitarian device exemption (HDE) from the FDA, a process that could take four to eight weeks and delay critical patient care. Dr. Varun Naragum, Director of the Baystate Neuroendovascular Program, said Baystate had previously relied on this pathway to treat patients who could not benefit from FDA-approved alternatives.
Baystate's selection reflects program volume and outcomes record in New England
Dr. Naragum said the site selection reflects the program's longstanding expertise in treating brain aneurysms and its record of patient outcomes, calling the rapid enrollment "a testament to the commitment and expertise of our team." The Baystate Neuroendovascular Program is among the busiest brain aneurysm treatment centers in New England.
Post-trial access will revert to exemption-only status pending full FDA clearance
Following completion of the study, use of the Silk Vista Baby device will be temporarily restricted again to humanitarian device exemption cases until full FDA approval is granted.