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.
The MemoryShape Core Study is a post-approval cohort study to assess safety and effectiveness in
augmentation, reconstruction, and revision (augmentation and reconstruction) patients. As part of the PMA conditions of approval, MemoryShape Core Study subjects will be expected to complete annual follow-up visits for safety and effectiveness through 10 years as well as MRI scans for all subjects at year 10.
Study Population Description
Women with Mentor¿s MemoryShape Breast Implants as indicated for primary augmentation, revision augmentation, primary reconstruction,
and revision reconstruction of the female breast.
A total of 955 subjects have been enrolled in MemoryShape Core Study. The protocol does
not specify the number of clinical sites.
During the 10-year follow-up period, long-term safety of the Implants will continue to be measured
by collecting the incidence, severity, method of resolution and duration for all complications (including device failures and adverse device effects) on a per-implant and per- patient basis. MRI scans to detect silent rupture of the implant for a subset of patients are at 1, 2,
4, 6, 8, and 10 years. Additionally, all patients are scheduled to receive MRI scans at year 6, 8 and 10. Safety assessments include complication rates, reasons for reoperation, and reasons for implant removal. Effectiveness assessments include bra cup size change (augmentation patients only), circumferential chest size change, measures of patients¿ satisfaction, and assessments of body image, self-esteem, and health related quality of life.
Followup Visits and Length of Followup
Subjects will be seen by the investigator in the investigator's office once a year until
all subjects have reached 10-years post-implantation. In addition, all subjects in the study are scheduled to receive MRI scan at 10 years post-implantation.
Final Study Results
Actual Number of Patients Enrolled
In total, 955 female subjects, including 572 primary augmentation, 124 revision-augmentation,
190 primary reconstruction, and 69
revision-reconstruction subjects, were enrolled.
Enrollment in the MRI Substudy included 252 primary augmentation, 56 revision-augmentation, 73 primary reconstruction, and 38 revision-reconstruction subjects.
Actual Number of Sites Enrolled
Patient Followup Rate
The follow-up rate at 10 years ranged from 60% to 74% across cohorts, with an
overall follow-up rate of
63%. The cohort specific follow-up rates were as follows: 60% primary augmentation, 63% revision- augmentation, 67% primary reconstruction, and 74% revision-reconstruction.
The follow-up rates at 10 years for the MRI subset of subjects ranged from 42% to 57% across cohorts, with an overall follow-up rate of 45%. The cohort specific MRI Substudy follow-up rates were as fo
Final Safety Findings
The Kaplan-Meier estimated cumulative incidence rates at the subject level for the complications of any
reoperation, explantation with or without replacement, explantation with replacement with study device, Baker III/IV capsular contracture, and infection are presented by cohort.
For the primary augmentation cohort, the KM estimated 10-year cumulative incidence rates were as follows: Baker Grade III/IV capsular contracture, 3.6%; infection, 0.7%; explantation with or without replacement, 9.2%; explantation with replacement with study device, 4.0%; and any reoperation, 22.3%.
For the revision-augmentation cohort, the KM estimated 10-year cumulative incidence rates were as follows: Baker Grade III/IV capsular contracture, 15.5%; infection, 1.9%; explantation with or without replacement, 25.9%; explantation with replacement with study device, 10.8%; and any reoperation, 35.0%.
For the primary reconstruction cohort, the KM estimated 10-year cumulative incidence rates were as follows: Baker Grade III/IV capsular contracture, 14.3%; infection, 1.6%; explantation with or without replacement, 34.1%; explantation with replacement with study device, 16.7%; and any reoperation, 52.7%.
For the revision-reconstruction cohort, the KM estimated 10-year cumulative incidence rates were as follows: Baker Grade III/IV capsular contracture, 16.4%; infection, 2.9%; explantation with or without replacement, 49.0%; explantation with replacement with study device, 27.9%; and any reoperation, 59.7%.
The Kaplan-Meier estimated cumulative incidence rates for rupture through 10 years for the MRI substudy subjects by cohort were: 6.6% primary augmentation, 9.6% revision- augmentation, 18.9% primary reconstruction, and 0% revision-reconstruction.
Final Effectiveness Findings
For the primary augmentation cohort, the overall mean change in circumferential chest size through 10
years was 2.1 inches and statistically significant (p<0.0001), and the overall mean bra cup size increase from baseline across all follow-up visits was 2.2 cup sizes and statistically significant (p<0.0001). The primary effectiveness analysis was for the primary augmentation cohort only.
The percentage of subjects who answered the Global Subject Satisfaction question indicating they would make the same decision to have breast implant surgery was 96.9% at the Year 10 follow-up visit. The results were similar for the four subject cohorts: 96.6%, 95.5%, 100.0%, and 94.1% for the primary augmentation, revision-augmentation, primary reconstruction, and revision-reconstruction cohorts, respectively.
Study Strengths and Weaknesses
One study strength is the 10-year prospective multi-center design to assess the long-term safety and
of the device. The weaknesses of the study were the lack of a comparison group, and lack of statistical power to detect rare events due to the sample size.
Recommendations for Labeling Changes
Yes, the labeling will be updated based on the post-approval study results to provide patients
and physicians with 10-year descriptive data on device performance.
OSB Lead-Post-Approval PMA Cohort Study (PACS)