Breast augmentation by autologous fat transfer is an appealing alternative in need of scientific validation. In a prospective multicenter study, 81 women (age range, 17 to 63 years) wore the Brava device, a bra-like vacuum-based external tissue expander, for 4 weeks and then underwent autologous fat injection using 10 to 14 needle puncture sites into each breast in a three-dimensional fanning pattern (average, 277 ml volume injected per breast). Patients resumed Brava wear within 24 hours for 7 or more days. Pretreatment and posttreatment breast volumes were derived from three-dimensional volumetric reconstruction of magnetic resonance imaging scans, and outcomes were compared with a meta-analysis of six recent published reports on autologous fat transfer breast augmentation without expansion. Follow-up ranged from 12 months to 6 years (average, 3.7 years). Breast volume was unchanged between 3 and 6 months. Seventy-one of the treated women were compliant with Brava wear and had a mean augmentation volume at 12 months of 233 ml per breast compared with 134 ml per breast in published series without Brava (p < 0.00001). Graft survival was 82 ± 18 percent compared with 55 ± 18 percent without Brava (p < 0.00001). There was a strong linear correlation (R = 0.87) between pregrafting Brava expansion and the resultant breast augmentation. There were no suspicious breast masses or nodules. Magnetic resonance imaging recognized a 16 percent incidence of fat necrosis easily identified at 1-year mammographic evaluation. : The addition of Brava expansion before autologous fat grafting leads to significantly larger breast augmentations, with more fat graft placement, higher graft survival rates, and minimal graft necrosis or complications, demonstrating high safety and efficacy for the procedure. Therapeutic, IV.

Learning Objectives: After reading this article, the participant should be able to: 1. Understand the theory and principles behind successful avascular fat transfer; 2. Apply these principles into techniques that yield safe and successful fat grafting operations; 3. Identify the well-established indications and limitations of the various fat grafting operations as well as the indications that require additional clinical and translational research. Summary: In this article, the authors summarize the established principles and techniques of fat grafting, discuss debated topics, and present both the well-established and the novel clinical applications of fat grafting.

The ability of autologous fat transfer to reconstruct an entire breast is not established. The authors harnessed the regenerative capabilities of external expansion and autologous fat transfer to completely reconstruct breasts. The authors performed 1877 Brava plus autologous fat transfer procedures on 616 breasts in 488 women to reconstruct 99 lumpectomies, 87 immediate breast reconstructions, and 430 delayed total breast reconstructions. After 2 to 4 weeks of Brava expansion, which increased volume by 100 to 300 percent, the authors diffusely grafted the breasts with 100 to 400 ml (225 ml average) of 15 g-sedimented, manually harvested lipoaspirate. The procedure was repeated every 8 to 14 weeks until completion. The authors compared costs of this reconstruction with established deep inferior epigastric artery perforator/transverse rectus abdominis musculocutaneous flaps and implant procedures. Follow-up ranged from 6 months to 7 years (mean, 2.5 years), with 0.5 percent locoregional recurrence. Four hundred twenty-seven women completed the reconstruction, whereas 12.5 percent dropped out (2.5 percent medical, 10 percent personal reasons). Completion required 2.7 procedures for nonirradiated and 4.8 procedures for irradiated mastectomies. Patients recovered soft, natural appearing breasts with nearly normal sensation. Complications included five pneumothoraces and 20 ulcerative infections. Radiographically recognized benign palpable masses were observed in 12 percent of nonirradiated and 37 percent of irradiated breasts. The cost of Brava plus autologous fat transfer is 47 percent and 66 percent that of current reconstruction alternatives. Brava plus autologous fat transfer is a minimally invasive, incisionless, safe, economic, and effective alternative for breast reconstruction. Therapeutic, IV.

This article describes the theory and principles behind the authors' success in megavolume (250-ml range) autologous fat transfer to the breasts. When large volumes are grafted into a tight space, the interstitial fluid pressure increases to impair capillary blood flow and the crowded graft droplets coalesce into lakes, with poor graft-to-recipient interface. These factors have historically restricted the volume of fat that can be grafted into small recipient breasts. The decreased interface increases the distance oxygen must diffuse to reach the grafted adipocytes, causing central necrosis to occur before neovascularization. The increased interstitial fluid pressure reduces capillary radius, reducing oxygen delivery to grafted adipose tissue. The Brava external expansion device harnesses the regenerative capabilities of mechanical forces to preoperatively increase the volume and vascularity of the recipient site, allowing megavolumes of fat to be grafted diffusely without significantly decreasing graft-to-recipient interface or increasing interstitial fluid pressure. The application of these principles has allowed the authors to successfully graft megavolumes of fat into the breasts of over 1000 patients with substantial long-term retention.

Fat grafting is now widely used in plastic surgery. Long-term graft retention can be unpredictable. Fat grafts must obtain oxygen via diffusion until neovascularization occurs, so oxygen delivery may be the overarching variable in graft retention. We studied the peer-reviewed literature to determine which aspects of a fat graft and the microenvironment surrounding a fat graft affect oxygen delivery and created 3 models relating distinct variables to oxygen delivery and graft retention. Our models confirm that thin microribbons of fat maximize oxygen transport when injected into a large, compliant, well-vascularized recipient site. The "Microribbon Model" predicts that, in a typical human, fat injections larger than 0.16 cm in radius will have a region of central necrosis. Our "Fluid Accommodation Model" predicts that once grafted tissues approach a critical interstitial fluid pressure of 9 mm Hg, any additional fluid will drastically increase interstitial fluid pressure and reduce capillary perfusion and oxygen delivery. Our "External Volume Expansion Effect Model" predicts the effect of vascular changes induced by preoperative external volume expansion that allow for greater volumes of fat to be successfully grafted. These models confirm that initial fat grafting survival is limited by oxygen diffusion. Preoperative expansion increases oxygen diffusion capacity allowing for additional graft retention. These models provide a scientific framework for testing the current fat grafting theories.

The authors describe the techniques that use the principles of fat grafting to allow them to successfully graft megavolumes (250-ml range) of autologous fat into breasts. The Brava external volume expansion device preoperatively increases the volume and vascularity of the recipient site. Low-pressure liposuction and minimal centrifugation are used to gently extract and purify the adipose tissue with minimal trauma. Even and diffuse reinjection of the fat increases graft-to-recipient interface and reduces interstitial fluid pressure. Postoperative Brava use protects the graft and acts as a three-dimensional immobilizing splint. By adhering to these techniques, we have been able to graft megavolumes of fat into the breasts of over 1000 patients and obtain substantial long-term volume retention.