Characterization of Adipose Tissue Product Quality Using Measurements of Oxygen Consumption Rate.

BACKGROUND: Fat grafting is a common procedure in plastic surgery but associated with unpredictable graft retention. Adipose tissue (AT) "product" quality is affected by the methods used for harvest, processing and transfer, which vary widely amongst surgeons. Currently, there is no method available to accurately assess the quality of AT. OBJECTIVES: In this study, we present a novel method for the assessment of AT product quality through direct measurements of oxygen consumption rate (OCR). OCR has exhibited potential in predicting outcomes following pancreatic islet transplant. Our study aim was to reapportion existing technology for its use with AT preparations and to confirm that these measurements are feasible. METHODS: OCR was successfully measured for en bloc and postprocessed AT using a stirred microchamber system. OCR was then normalized to DNA content (OCR/DNA), which represents the AT product quality. RESULTS: Mean (±SE) OCR/DNA values for fresh en bloc and post-processed AT were 149.8 (± 9.1) and 61.1 (± 6.1) nmol/min/mg DNA, respectively. These preliminary data suggest that: (1) OCR and OCR/DNA measurements of AT harvested using conventional protocol are feasible; and (2) standard AT processing results in a decrease in overall AT product quality. CONCLUSIONS: OCR measurements of AT using existing technology can be done and enables accurate, real-time, quantitative assessment of the quality of AT product prior to transfer. The availability and further validation of this type of assay could enable optimization of fat grafting protocol by providing a tool for the more detailed study of procedural variables that affect AT product quality.

Postmastectomy Reconstruction Outcomes After Intraoperative Evaluation with Indocyanine Green Angiography Versus Clinical Assessment.

BACKGROUND: Mastectomy flap necrosis is a major complication in patients undergoing tissue expander-based reconstruction. This study compared the complication rates following mastectomy and immediate reconstruction with intraoperative indocyanine green (ICG) angiography evaluation to those with clinical assessment only. METHODS: We performed a single-institution retrospective study of mastectomy patients who underwent immediate tissue expander-based reconstruction between September 2009 and December 2013. ICG angiography was adopted in March 2012. The rates of complications in the ICG and clinical assessment only groups were compared. Factors associated with complications were identified with the Fischer exact test and univariate analysis. RESULTS: A total of 114 patients were identified; clinical assessment only, 53 patients; ICG angiography, 61 patients. The overall complication rates were not significantly different between the two groups (ICG angiography, 50.8 %; clinical assessment, 43.4 %; p = 0.46). There was no significant difference in the rates of unexpected return to the operating room, cellulitis, hematomas, and seromas. The overall rates of flap necrosis were not significantly different (ICG angiography, 27.9 %; clinical assessment, 18.9 %; p = 0.28). However, the rates of severe flap necrosis were significantly lower with intraoperative ICG angiography (4.9 %) than with clinical assessment only (18.9 %, p = 0.02). On univariate analysis, breast weight (≥500 g) was significantly associated with increased rates of severe flap necrosis (p = 0.04), whereas body mass index, age, smoking status, prior breast surgery, history of radiation therapy, and receipt of nipple-sparing mastectomy were not. CONCLUSIONS: We observed that the implementation of intraoperative ICG angiography was associated with a significant decrease in the rate of severe flap necrosis.

Characterization of adipose tissue for autologous fat grafting.

Fat grafting is a common procedure in aesthetic and reconstructive plastic surgery, but variable graft retention limits its utility. Unpredictable clinical outcomes with fat grafting can be explained in part by the lack of standardized protocols for harvesting, processing, and transplanting adipose tissue (AT). Historically, plastic surgeons have relied on trial and error and their clinical experience to develop fat grafting protocols. Optimization of fat grafting protocols requires systematic assessment of the impact that key variables have on the quality of the AT preparation at each step of the procedure. In this article, we review recent findings regarding the composition and quality of AT prepared for fat grafting and the strengths and limitations of existing AT characterization assays. We discuss the need for an assessment of the viability of intact AT (ie, conventionally harvested AT that has not been disrupted further) by means of an operator-independent, quantitative assay that can be performed in real time and generates reproducible data. Promising assays for the characterization of cell product quality have been developed for other therapeutic applications, such as transplantation of pancreatic islet cells. The development or adaptation of a gold-standard assay to determine the quality of an AT preparation may help to standardize fat grafting protocols and improve clinical outcomes.

Bioengineered Approach to the Design of a Fat Graft Based on Mathematical Modeling that Predicts Oxygen Delivery.

BACKGROUND: Fat grafting is a common procedure in plastic surgery. A major limitation is unpredictable graft retention, in part caused by inadequate oxygen delivery during the early posttransfer period. METHODS: The authors present a bioengineered approach to the design of a fat graft based on mathematical theory, which can estimate the limitations of oxygen delivery. To simplify the problem, four variables were defined: (1) recipient-site oxygen partial pressure; (2) adipose tissue oxygen permeability; (3) adipose tissue oxygen consumption rate; and (4) fat graft size. Recipient-site oxygen partial pressure and adipose tissue oxygen permeability were estimated from literature, whereas adipose tissue oxygen consumption rate was measured using stirred microchamber technology. Calculations were performed in both spherical and planar geometry to calculate the maximum allowable fat graft size from an oxygen delivery standpoint. RESULTS: As expected, planar geometry is less favorable for oxygenation but represents a realistic configuration for a fat graft. Maximum allowable fat graft thickness is only approximately 1 to 2 mm at external oxygen partial pressures of 10 to 40 mm Hg; any thicker and an anoxic or necrotic core likely develops. Given a reasonably large surface area and assuming several planes of injection, the maximum allowable fat graft volume is tens of milliliters. CONCLUSIONS: A systematic bioengineered approach may help better design a fat graft. Applying principles of mass transfer theory can predict whether a fat graft has a favorable chance of surviving from an oxygen delivery standpoint and can direct the development of strategies for improved fat graft oxygenation.

MemoryShape: impact of clinical trials, global medical economics, and the future.

The global breast implant business was invented and configured by American plastic surgeons. In 2012, the first shaped silicone implants were approved in the United States by the Food and Drug Administration. It is the peculiar historical course of implant usage in America that has deprived US plastic surgeons of the opportunity to become experts in the use of this device. Most studies indicate significant safety benefits to using shaped devices, despite the technical challenges involved in their use. Upon approval, adoption of the devices has been slow in the United States, running the risk that American plastic surgery may lose the intellectual and clinical practice hegemony it has enjoyed for over 50 years in this area of the specialty. To continue to maintain leadership in the field of breast surgery, US surgeons should evaluate this new modality and either join the global trend or present data to contradict it.

Eighth IQUAM consensus conference position statement: Transatlantic innovations, April 2009.

BACKGROUND: On April 7, 2009, the International Committee for Quality Assurance, Medical Technologies and Devices in Plastic Surgery (IQUAM) issued its 8th Position Statement. IQUAM is a professional medical and scientific organization committed to the surveillance of existing and new technologies and devices in plastic surgery. IQUAM periodically reviews and evaluates updated international literature and studies and scientific data, and recommends standards of treatment for plastic surgery devices and technologies. IQUAM proscribes potentially deleterious use of products, devices, and technologies, or their unintended application or application for unsuitable indications. METHODS: Presentations of an international panel of experts made during the Transatlantic Innovations Symposia in Paris, in April of 2009, were reviewed by an advisory board that prepared the position statement for distribution to plastic surgeons and regulatory bodies. The advisory panel was international in nature and included plastic surgeons with expertise in the specific areas evaluated. RESULTS: Three clinical areas of greatest concern to plastic surgeons were evaluated for efficacy and safety: silicone breast implants, tissue engineering, and injectable therapies. CONCLUSION: Specific recommendations designed to increase clinical safety and patient education for informed consent were made in each area.

Analysis of breast reduction complications derived from the BRAVO study.

BACKGROUND: Analysis of complication data derived from the Breast Reduction Assessment: Value and Outcomes (BRAVO) study, a 9-month prospective, multicenter trial, is presented. METHODS: Data derived from 179 patients were analyzed, including bivariate associations between complications and single predictor variables (Fisher's exact test or chi-square testing) or continuous variables (two-sample t test) and, finally, logistic regression. RESULTS: The overall complication rate was 43 percent (77 patients). Simple, bivariate analysis linked preoperative breast volume, shoulder strap grooving, and a vertical incision with an increased incidence of complications (p < 0.05, 0.02, and 0.02, respectively). Delayed wound healing, the most common complication, correlated directly with average preoperative breast volume (p < 0.045), average resection weight/breast (p < 0.027), and smoking (p < 0.029) and inversely with age (p < 0.011). Vertical incision techniques were associated with an increased complication frequency (p < 0.05) without a link to specific complications. Logistic regression analysis associated resection weight as the sole variable for increased risk of complications (p = 0.05) and with absolute number of complications [mean resection weight of 791 g for patients without complications versus 847, 882, and 1752 g for patients with one, two, and three complications, respectively (p = 0.0022)]. Each 10-fold increase in resection weight increased the risk of complication 4.8 times and increased the risk of delayed healing 11.6 times. CONCLUSIONS: Complication data revealed several significant features: (1) resection weight correlated with increased risk and absolute number of complications; (2) delayed healing correlated directly with resection weight and inversely with increasing age, anesthesia times, and preoperative Short Form-36 bodily pain score; (3) a vertical incision may be associated with increased incidence of complications but requires further analysis; and most importantly, (4) the presence of complications had no negative effect on improvement in Short Form-36 and Multidimensional Body-Self Relations Questionnaire scores.