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.
Transit. Adolescent B (as adults) : 18-21 yrs,
Detailed Study Protocol Parameters
Study Design Description
New enrollment, multi-center, prospective cohort
Study Population Description
The study population is comprised of patients aged 50 years and older who have lumbar
spinal stenosis, suffers symptoms of neurogenic intermittent claudication, have moderately impaired physical function, and are able to relieve their symptoms when they bend forward or flex their spines.
The sample size is 240 patients and 30 clinical sites
The primary endpoint is the Zurich Claudication
Questionnaire (ZCQ) score.
Secondary endpoints include Oswestry Disability Index scores
and MRI changes in adjacent discs.
Followup Visits and Length of Followup
The length of follow-up is 5 years.
Office visits are scheduled preoperatively, and at 6 weeks
2, 3, 4, and 5 years postoperatively.
Categorical data will be summarized using frequency tables with
proportions, exact 95% confidence intervals presented. Summaries of continuous data will include mean, standard deviation, median, minimum and maximum. To represent device survival assessment, Kaplan- Meier analyses will be conducted.
Final Study Results
Actual Number of Patients Enrolled
162 patients were enrolled.
Actual Number of Sites Enrolled
20 sites participated in enrollment.
Patient Followup Rate
The follow-up rate of expected subjects is 91.53% and 91.67% at the 24-month and 60-month
visit, respectively. The attrition rate due to death, lost to follow-up and withdrawal is 5.56% and 27.16% at the 24-month and 60-month visit, respectively.
Final Safety Findings
Adverse Events (AEs) Summary:
Through August 15, 2014, a total of 814 adverse events were reported
by 132 (81.5%) patients. The most common category of AEs was musculoskeletal and connective tissue disorders, reported by 88 (54.3%) patients and the most commonly reported adverse event was back pain, reported by 36 (22.2%) patients. Within this set of AEs, thirty-two events were reported for 18 (11.1%) patients to be implant-related while 51 events reported in 27 (16.7%) patients were classified as X-STOP procedure-related. The most frequently reported implant-related AE was device removal reported in 10 (6.2%) patients. The most frequently reported procedure-related AEs were incisional site pain in 7 (4.3%) patients, and spinal fracture in 6 (3.7%) patients.
Serious Adverse Events (SAEs) Summary:
Through August 15, 2014, a total of 210 serious adverse events have been reported by 65 (40.1%) patients. Within this set of SAEs, 26 events were reported for 15 (9.3%) patients to be implant-related while five events reported in 3 (1.9%) patients were classified as X-STOP procedure-related.
Subsequent Lumbar Surgery
There were 39 secondary surgery forms completed in thirty-two (19.8%) patients with 28 (17.3%) patients reporting X-STOP removal.
Overall success rates for the study participants were observed as follows:
12 months, 44.8%; 24 months, 30.9%; and 60 months, 24.2%.