Jonathan D. McCue

Safety and Effectiveness of Mentor’s MemoryGel Implants at 6 Years

BackgroundIn November 2006, the FDA approved the Premarket Approval PMA applications for the round, cohesive, silicone gel-filled breast implants of Mentor (MemoryGel) and Allergan. Since that time, the devices have been widely available to plastic surgeons and their use is rapidly eclipsing that of the saline breast implants. Patients in the Core clinical studies supporting these approvals continue to be followed through for 10 years, with comprehensive annual patient and physician-reported evaluations of safety and efficacy.MethodsOne thousand and eight (1,008) female patients had data collected on 1,898 implants, and were enrolled at 48 sites. Key complication rates were recorded with Kaplan–Meier estimated cumulative incidence calculation for each.ResultsRupture rate, suspected and confirmed, for primary augmentation was 1.1% (95% CI, 0.3–4.3), and that for primary reconstruction patients was 3.8% (95% CI, 1.4–9.8). Capsular contracture rates for clinically significant Baker III/IV contracture for primary augmentation was 9.8% (95% C I, 7.6–12.7), and that for primary reconstruction was 13.7% (95% CI, 9.7–19.1). The reoperation incidence for primary augmentation and primary reconstruction was 19.4 and 33.9%, respectively, with explantation and replacement with a study device in 3.9% of primary augmentations and 10.4% of primary reconstructions.ConclusionsMentor MemoryGel Silicone Breast implants represent a safe and effective choice for women seeking breast augmentation or breast reconstruction following mastectomy.

Multipotent adult progenitor cells sustain function of ischemic limbs in mice.

Despite progress in cardiovascular research, a cure for peripheral vascular disease has not been found. We compared the vascularization and tissue regeneration potential of murine and human undifferentiated multipotent adult progenitor cells (mMAPC-U and hMAPC-U), murine MAPC-derived vascular progenitors (mMAPC-VP), and unselected murine BM cells (mBMCs) in mice with moderate limb ischemia, reminiscent of intermittent claudication in human patients. mMAPC-U durably restored blood flow and muscle function and stimulated muscle regeneration, by direct and trophic contribution to vascular and skeletal muscle growth. This was in contrast to mBMCs and mMAPC-VP, which did not affect muscle regeneration and provided only limited and transient improvement. Moreover, mBMCs participated in a sustained inflammatory response in the lower limb, associated with progressive deterioration in muscle function. Importantly, mMAPC-U and hMAPC-U also remedied vascular and muscular deficiency in severe limb ischemia, representative of critical limb ischemia in humans. Thus, unlike BMCs or vascular-committed progenitors, undifferentiated multipotent adult progenitor cells offer the potential to durably repair ischemic damage in peripheral vascular disease patients.

Pretransplant cachexia and morbid obesity are predictors of increased mortality after heart transplantation

Background. Extremes in body weight are a relative contraindication to cardiac transplantation. Methods. We retrospectively reviewed 474 consecutive adult patients (377 male, 97 female, mean age 50.3±12.2 years), who received 444 primary and 30 heart retransplants between January of 1992 and January of 1999. Of these, 68 cachectic (body mass index [BMI]<20 kg/m2), 113 overweight (BMI=>27–30 kg/m2), and 55 morbidly obese (BMI>30 kg/m2) patients were compared with 238 normal-weight recipients (BMI=20–27 kg/m2). We evaluated the influence of pretransplant BMI on morbidity and mortality after cardiac transplantation. Kaplan-Meier survival distribution and Cox proportional hazards model were used for statistical analyses. Results. Morbidly obese as well as cachectic recipients demonstrated nearly twice the 5-year mortality of normal-weight or overweight recipients (53% vs. 27%, respectively, P =0.001). An increase in mortality was seen at 30 days for morbidly obese and cachectic recipients (12.7% and 17.7%, respectively) versus a 30-day mortality rate of 7.6% in normal-weight recipients. Morbidly obese recipients experienced a shorter time to high-grade acute rejection (P =0.004) as well as an increased annual high-grade rejection frequency when compared with normal-weight recipients (P =0.001). By multivariable analysis, the incidence of transplant-related coronary artery disease (TCAD) was not increased in morbidly obese patients but cachectic patients had a significantly lower incidence of TCAD (P =0.05). Cachectic patients receiving oversized donor hearts had a significantly higher postoperative mortality (P =0.02). Conclusions. The risks of cardiac transplantation are increased in both morbidly obese and cachectic patients compared with normal-weight recipients. However, the results of cardiac transplantation in overweight patients is comparable to that in normal-weight patients. Recipient size should be kept in mind while selecting patients and the use of oversized donors in cachectic recipients should be avoided.

Ninety-day mortality and major complications are not affected by use of lung allocation score.

BACKGROUND In May 2005 the Organ Procurement Transplant Network (OPTN) and United Network for Organ Sharing (UNOS) implemented the donor lung allocation score (LAS) system to prioritize organ allocation among prospective transplant recipients. The purpose of our study was to determine the impact of LAS implementation on 90-day survival, early complications and incidence of severe primary graft dysfunction (PGD) after the transplant procedure. METHODS Early outcomes among 78 patients receiving transplants after the initiation of the scoring system were compared with those of the 78 previous patients. Survival rates at 90 days and 1 year were the primary end-points of the study. Arterial blood-gas measurements were collected for all patients at the time of ICU arrival and at 12, 24 and 48 hours after surgery to determine the distribution of International Society of Heart and Lung Transplant (ISHLT) PGD grade. Major complications within 30 days post-transplant were recorded. RESULTS We found a small but significant 1-year survival advantage among post-LAS implementation patients, which was largely due to decreased early mortality in comparison to the control cohort. The incidence of ISHLT Grade 3 PGD measured within the first 24 hours after transplant did not differ between groups, nor was there an increase in the rate of major post-operative complications. CONCLUSIONS Implementation of the LAS system has not been associated with an increase in early mortality, immediate PGD or major complications.

THE REAL ESTATE OF MYOBLAST CARDIAC TRANSPLANTATION – NEGATIVE REMODELING IS ASSOCIATED WITH LOCATION

BACKGROUND Skeletal myoblast transplantation has been proposed as a therapy for ischemic cardiomyopathy owing to its possible role in myogenesis. The relative safety and efficacy based on location within scar is not known. We hypothesized that skeletal myoblasts transplanted into peripheral scar (compared with central scar) would more effectively attenuate negative left ventricular (LV) remodeling but at the risk of arrhythmia. METHODS New Zealand White rabbits (n = 34) underwent mid-left anterior descending artery (LAD) ligation to produce a transmural LV infarction. One month after LAD ligation, skeletal myoblasts were injected either in the scar center (n = 13) or scar periphery (n = 10) and compared with saline injection (n = 11). Holter monitoring and magnetic resonance imaging (MRI) was performed pre-injection; Holter monitoring was continued until 2 weeks after injection, with follow-up MRI at 1 month. RESULTS The centrally treated animals demonstrated increased LV end-systolic volume, end-diastolic volume, and mass that correlated with the number of injected cells. There was a trend toward attenuation of negative LV remodeling in peripherally treated animals compared with vehicle. Significant late ectopy was seen in several centrally injected animals, with no late ectopy seen in peripherally injected animals. CONCLUSIONS We noted untoward effects with respect to negative LV remodeling after central injection, suggesting that transplanted cell location with respect to scar may be a key factor in the safety and efficacy of skeletal myoblast cardiac transplantation. Administration of skeletal myoblasts into peripheral scar appears safe, with a trend toward improved function in comparison with sham injection.

Breast tissue expander device volume: should it be a factor?

Implant-based breast reconstruction is frequently achieved by tissue expansion following mastectomy. A variety of tissue expanders are available for this purpose; however, there are common device features, including a one-way fill port and durable silicone shell that can withstand significant fill pressures.1,2 These features contrast to the thin silicone outer shell of either saline or gel permanent implants that are used in second-stage reconstruction.3 The process of second-stage reconstruction requires the selection of a permanent implant based on objective criteria such as base diameter, volume, and profile.4 Implant volume is often based on the volume of saline administered during the expansion process. Many surgeons do not use permanent implants that precisely match the volume of the filled expander, preferring overexpansion to a larger pocket and subsequently using a smaller implant.5 Nonetheless, fill volume is frequently relied on as the only objective measure of the pocket size. As the typical tissue expander has a larger construct volume than a permanent implant shell, the volume occupied by the expander itself should be factored in. We hypothesized that the contribution of the expander itself to the final pocket volume is significant, and sought to measure this among an array of tissue expanders using the most precise means possible.

Erratum: Safety and effectiveness of Mentor's MemoryGel implants at 6 years (Aesthetic Plastic Surgery DOI: 10.1007/s00266-009-9364-6)

As reported in the Patients and Methods section, at the time of the 6-year follow-up 608 patients, instead of 552 as originally reported, were evaluated, with an overall followup of 64%. As presented in Fig. 2, one of the primary reasons for explantation through 6 years was capsular contracture III/ IV at 25.6% for the Revision-Augmentation cohort and 16.4% for the Reconstruction cohort. For Augmentation and Revision-Reconstruction patients, the percentages for contracture III/IV, 19.7% and 29.4%, respectively, were the same as II/III/IV, as reported in the text.