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 is a prospective, single-arm, multi-center study designed to look at the long-term re-operation rates
seen with the Swedish Adjustable Gastric Band.
Study Population Description
Study population: Subjects are between the ages of 18 and 60 years old who have
been diagnosed with morbid obesity and considered appropriate candidates for surgical weight reduction. Indication: Patients with one or more significant medical conditions related to obesity for which the subject is being treated, and which are generally expected to be improved by weight loss. Body Mass Index (BMI) must be greater than or equal to 35 kg/m2 and less than or equal to 40 kg/m2.
300 patients, 8 sites
The primary endpoint is the re-operation rate (including band revisions, band replacements, and explants) in
years four and five post-implant. Secondary endpoints are: HbA1c levels, serum lipid levels, amount of excess body weight loss, quality of life measured by SF-36, Beck Depression Inventory scale score, adverse event rate, severe adverse event rate
Followup Visits and Length of Followup
Subjects will be followed for five years. During year 1 following implant, evaluations take place
at 1, 2, 4, 6, 8, and 10 months. Evaluations will then take place at 12 months, 24 months, 36 months, 48 months, and 60 months.
Final Study Results
Actual Number of Patients Enrolled
Actual Number of Sites Enrolled
Patient Followup Rate
Final Safety Findings
The primary safety goal of this study was to determine the reoperation rate (band revision,
band replacement, and explants resulting from Serious Adverse Events (SAEs)) of gastric banding at 4 and 5 years post implant. The safety success criterion for this study was an observed device-related reoperations rate significantly lower than 8% for Years 4 and 5 of the study. The observed reoperation rate in the post-approval study was 8.9% with an upper bound 95% confidence interval of 12.08%, which results in failure to reject the null hypothesis (H0: Reoperation rate ? 8%). Therefore, there is no evidence that the reoperation rate is less than 8%.
The most commonly occurring AE related to the study device was GI disorders with 1,117 events experienced by 246 (81.2%) subjects. Of all the adverse events that occurred in Years 4 and 5 of the study, the most commonly occurring AE related to the study device was GI disorders with 289 events experienced by 155 (51.2%) subjects. Overall, gastroesophageal reflux disease (14.2%), vomiting (13.5%), esophageal dilation (8.9%), dysphagia (7.9%), and gastric dilatation (6.3%). The overall explant rate was 8.9% with a 95% CI range of 6.0% to
Most Frequently Occurring Device Related Serious Adverse Events include: device migration (9.2%), catheter related complication (5.0%), cholelithiasis (4.3%), cholecystitis (2.6%), and gastric dilatation (2.3%) were the most common SAEs reported throughout the entire study.
Final Effectiveness Findings
As a result of the reduction in BMI, important and statistically significant reductions in the
lipid profile were achieved and were reported since the first year of follow-up including reductions in LDL, triglycerides, and HbA1c values, which were maintained throughout the remainder of the study. There was a statistically significant change in BMI values between each yearly time point and the value at screening. However, there was not a statistically significant change appreciated in the total cholesterol levels. The following are detailed results at 5-years post- surgery in the ITT population:
? %EWL was 35.6 ± 26.84;
? Mean reduction in BMI (kg/m2) was -7.0 ± 5.45 (95% CI: -7.7 to -6.3);
? Mean reduction in absolute weight (lb) and mean % in weight reduction (%) was -43.1 ±
32.5 (95% CI: -47.3 to -39.0), and 16.0 ± 11.9 (95% CI: 14.5 to 17.6) respectively;
? The Physical Component score and the domain scores for SF-36 showed improvement at every post-surgery visit;
? The total transformed score and the domain scores for the IWQOL-Lite showed improvement at every post-surgery visit in the CI-07-0006 cohort;
? Mean reduction in HbA1c (%) was -0.22 ± 0.823 (95% CI: -0.33 to -0.11), which was statistically significant;
? Mean increase in HDL (mg/dL) was 9.3 ± 11.51 (95% CI: 7.7 to 10.8), which was statistically significant;
? Mean reduction in LDL (mg/dL) was -7.3 ± 31.90 (95% CI: -11.6 to -3.0), which was statistically significant;
? Mean reduction in total cholesterol (mg/dL) was -2.0 (95% CI: -7.8 to 2.0), which was not
statistically significant; and
? Mean reduction in triglycerides (mg/dL) was -28.2 ± 110.15 (95% CI: -42.7 to -13.7), which was statistically significant.
Study Strengths and Weaknesses
Enrollment was successful: A sample size of 300 was expected and a total of 303
A five-year follow-up was achieved providing long-term safety and effectiveness data. Weaknesses:
No concurrent comparison group, which limits interpretation of the results. Based on this one study, statements comparing the device to alternative treatments cannot be
A 77% follow-up rate was attained. Loss to follow-up limit the interpretation of the study results. The subjects that remain in the study may be different to those that were lost, and therefore, the generalizability of results can be limited.
Recommendations for Labeling Changes
PAS study data must be added to the labeling including: description of the study design
and methods, and the new safety information through 5 years of follow-up.