Showing papers by "Northampton Community College published in 2022"
13 Jul 2022
TL;DR: In 2018, Calobrace et al. as discussed by the authors investigated the relationship between shell thickness and device failure, and concluded that a thicker implant may not necessarily guarantee a better rupture rate.
Abstract: We thank the editors for the opportunity to respond to inaccuracies and mischaracterizations in the invited discussion1 that accompanied our study.2 1. The warning letter referenced was actually focused on a different device, a different study, and a different issue. As detailed in our publication, “62 percent follow-up at 10 years after implantation is equivalent to 95.3 percent follow-up each year of patients from the prior year.”2 Similar follow-up rates for both primary augmentation and primary reconstruction patients have been observed across different manufacturers’ 10-year core studies.3–7 2. Regarding the discussant’s unfamiliarity with the rupture findings, in addition to the various presentations at national plastic surgery conferences that have included these data, they have been widely available for years (see the publications listed in Table 1). 3. The 2019 U.S. Food and Drug Administration document cited stated that “due to the differences in the methods in which ruptures were detected and confirmed, the types of data that were collected, length and frequency of patient follow-up, and the methods for analyzing and presenting the data greatly limited the comparisons that can be made between manufacturers.” As such, the manufacturer-to-manufacturer comparison of estimated rupture rates is neither appropriate nor valid. The discussant also did not highlight that the quoted rate was a Kaplan-Meier estimate of the “suspected and confirmed” incidence as opposed to the 9.8 percent confirmed rate. 4. Regarding the correlation between shell thickness and device failure, biomaterials expert Dr. Stephen Li addressed this issue of shell thickness and device rupture at a Food and Drug Administration panel hearing8: Table 1. - Rupture Findings Available Online Document Source Year Summary Basis of Decision–Mentor MemoryGel Silicone Gel-Filled Breast Implants* Health Canada 2014 Long-Term Safety of Textured and Smooth Breast Implants† Aesthetic Surgery Journal 2017 FDA Executive Summary Breast Implant Special TopicsPrepared for the Meeting of the General and Plastic Surgery Devices Advisory Panel‡ U.S. Food and Drug Administration 2019 *Health Canada. Summary basis of decision–Mentor MemoryGel silicone gel-filled breast implants. Health Canada. January 17, 2014. Available at: https://hpr-rps.hres.ca/reg-content/summary-basis-decision-medical-device-detailOne.php?lang=en&linkID=SBD00412. Accessed March 15, 2021.†Calobrace MB, Schwartz MR, Zeidler KR, Pittman TA, Cohen R, Stevens WG. Long-term safety of textured and smooth breast implants. Aesthet Surg J. 2017;38:38–48.‡U.S. Food and Drug Administration. FDA executive summary breast implant special topics prepared for the meeting of the general and plastic surgery devices advisory panel, March 25 and 26, 2019. 2019. Available at: https://www.fda.gov/media/122956/download. Accessed March 15, 2021. “From the fraction mechanics point, a thicker implant doesn’t necessarily guarantee you better rupture. In fact, depending if it’s permanent set, a thicker wall actually may work against you in terms of rupture. So it is just not clear, out of these rupture mechanisms, what the influence of thickness is.” For example, although measurements of shell thickness (at three different places on 10 implants each) indicate the silicone elastomer shells of Mentor MemoryGel breast implants (Mentor Worldwide LLC, Irvine, Calif.) are approximately 35 percent thinner than those of another manufacturer (0.0155 inches versus 0.0213 inches), the shell strength as assessed by maximum tensile stress, in pounds per square inch (using one of the primary standardized tests set forth in Food and Drug Administration guidance for evaluating breast implant shell durability), was approximately 30 percent greater (1652 versus 1267). 5. Regarding the concern of downplaying the risk of intracapsular rupture, the source cited is a web page question-and-answer that includes individual viewpoints of six surgeons whose statements include “A broken implant is somewhat controversial as to removal or not” and “Over the years, I have followed many patients with known ruptured silicone breast implants and no symptoms … We have changed the implants only when there were symptoms, and have never had anyone develop a problem where we wished we had done something sooner.” A review by Hillard and colleagues9 expressed a similar view: “The majority of silicone implant ruptures are clinically undetectable and pose no significant health risks.” Mentor device labeling nevertheless explicitly recommends removal of known ruptured devices. We also express the hope that future invited discussions would more closely align with the long-standing respectful tone that is more reflective of one of the premiere plastic surgery journals. DISCLOSURE Dr. Caplin is a consultant and clinical investigator for Mentor Worldwide, LLC, and Establishment Labs. Dr. Calobrace has no financial disclosures to report. Dr. Wixtrom is a consultant for Mentor Worldwide. Dr. Estes and Dr. Canady were employees of Mentor Worldwide at the time of writing of this letter. Dr. Estes is now an employee of Boston Scientific. Dr. Canady is now retired. This study was sponsored by Mentor Worldwide, LLC. David A. Caplin, M.D.Parkcrest Plastic Surgery and Division of Plastic SurgeryDepartment of SurgeryWashington UniversitySt. Louis, Mo. M. Bradley Calobrace, M.D.Private practice and Division of Plastic SurgeryDepartment of SurgeryUniversity of LouisvilleLouisville, Ky.University of KentuckyLexington, Ky. Roger N. Wixtrom, Ph.D.LSCISpringfield, Va. Megan M. Estes, Ph.D.John W. Canady, M.D.Mentor Worldwide, LLCIrvine, Calif.