In January 2005, the oversight responsibility of the Post-Approval Studies Program was transferred to the Division of Epidemiology (DEPI) of the Office of Surveillance and Biometrics (OSB)/Center for Devices and Radiological Health (CDRH).
The CDRH Post-Approval Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated as a condition of approval of a premarket approval (PMA) application, protocol development product (PDP) application, or humanitarian device exemption (HDE) application. The program helps ensure that well-designed post-approval studies (PAS) are conducted effectively and efficiently and in the least burdensome manner.
CDRH has established an automated, internal tracking system that efficiently identifies the reporting status of active PAS studies ordered since January 1, 2005 based on study timelines incorporated in study protocols and agreed upon by the CDRH and applicants. This system represents CDRH's effort to ensure that all PAS commitments are fulfilled in a timely manner.
In addition, CDRH launched this publicly available webpage to keep all stakeholders informed of the progress of each PAS. The webpage displays general information regarding each PAS, as well as the overall study status (based on protocol-driven timelines and the adequacy of the data) and the applicant's reporting status for each submission due.
This was a nonrandomized, open-label study intended to confirm the safety of the NexStent
System and the FilterWire EZ Embolic Protection System in routine clinical practice and to identify rare or unanticipated device-related events that may occur with the use of this system.
Study Population Description
Study Population: Patients with neurological systems associated with >50% stenosis of the common or internal
carotid artery OR patients without neurological symptoms and >80% stenosis of the common or internal carotid artery by ultrasound or angiogram and patients must have a reference vessel diameter within the range of 4 mm and 9 mm at the target lesion and a stenosis less than 30 mm in length. Indication: The NexStent Carotid Stent System used in conjunction with the FilterWire EZ System, is indicated for treatment of patients at high risk for adverse events from carotid endarterectomy who require carotid revascularization.
1650 patients, number of sites not specified
The primary endpoints included 30-day rate of major adverse events defined as all deaths, strokes,
and myocardial infarctions that occur within 0-30 days, 12-month composite rate of major adverse events, and ipsilateral stroke events that occur within 31-365 days for all subjects.
Followup Visits and Length of Followup
Though 1,650 subjects were planned for the SONOMA study, only 298 had been enrolled at
the point of study termination. Subjects were to be evaluated at 30 day and 12 month follow-up. As of July 24, 2009, the follow-up of all enrolled subjects (87.5%) was completed.
Final Study Results
Actual Number of Patients Enrolled
Actual Number of Sites Enrolled
Patient Followup Rate
Final Safety Findings
The sponsor voluntarily recalled this device in June of 2008 due to complaints involving detachment
of the tip from the stent delivery System.
Study Strengths and Weaknesses
Strengths: Post approval study aided in uncovering problem with stent delivery. Weaknesses: There was no