- CAL converts progenitor-poor harvested fat to progenitor-normal or enriched fat tissue before transplantation
- Additional technique improvements, longer follow-up studies may allow autologous tissue transfer to become more widely used for breast augmentation and reconstruction
Breast augmentation techniques employing fat grafts are growing in popularity, but in many cases they are still hindered by variability in volume achieved and longevity of results. Japanese plastic surgeon Kotaro Yoshimura, M.D., department of plastic surgery, University of Tokyo Graduate School of Medicine, is making strides in improving the outcomes of fat grafting for breast augmentation with his cell-assisted lipotransfer (CAL) technique.
CAL converts progenitor-poor harvested fat to progenitor-normal or enriched fat tissue before transplantation.1 Dr. Yoshimura discussed his technique at the 9th annual Anti-Aging Medicine World Congress & Medispa in Monte Carlo in March. His presentation illustrated how adipose tissue is remodeled after grafting; how stem cells work in the remodeling process; how an adipocyte dies when removed from the tissue; and how new adipocytes are born and grow.
A 30-year-old female patient before (top) and after breast augmentation at 24 months. The patient underwent breast augmentation with CAL (310 mL in each breast). Results demonstrated an 8.0 cm increase in breast circumference at 24 months. The breast mounds were soft with no subcutaneous indurations. An original inframammary fold on the left breast is slightly visible, but injection scars are not visible. (Photos credit: Kotaro Yoshimura, M.D.)
CAL BOOSTS EFFICACY In CAL, autologous adipose-derived stem (stromal) cells (ADSCs) are used in combination with lipoinjection. A stromal vascular fraction (SVF) containing ADSCs is freshly isolated from half of the aspirated fat tissue and recombined with the other half. "Relative deficiency of adipose progenitor cells in aspirated fat tissue may lead to long-term atrophy of the grafts, whereas supplementation of vascular stromal fraction containing adipose progenitor cells may boost the efficacy and safety of lipoinjection to the breasts," Dr. Yoshimura says.
Dr. Yoshimura has performed more than 550 CAL breast augmentation procedures since 2003. He describes the basis of his technique this way: "Stem cells work as adipose progenitor cells and contribute to regenerating adipose tissue after lipografting. Grafted adipose tissue mostly dies and is then regenerated. Adipose progenitor cells contribute to the reconstruction of adipocytes and capillaries in the regenerating fat. Aspirated fat tissue is generally progenitor-poor and the deficiency in progenitor cells is compensated for by adding adipose progenitor cells."
A 36-year-old female patient before (top) and after breast augmentation view 12 months. The patient, whose body mass index was 17.3, underwent breast augmentation with CAL (245 mL in each breast). The breast mounds were soft with no subcutaneous indurations or visible scars at 12 months.
Dr. Yoshimura reports that he has tweaked his technique in small but important ways throughout its evolution. "We have not changed the main strategy but have modified some of our devices and surgical techniques in details," he says. "For instance, we developed a new syringe for a large-volume injection to the breast, which is a 'screw-type' syringe to achieve diffuse and precise distribution of fat."
Dr. Yoshimura's CAL breast augmentation retention results fall in the 40 to 80 percent range. He admits these results are variable, but says the results are much better than conventional fat-grafting augmentation procedures that do not convert progenitor-poor fat to progenitor-normal or enriched fat.
"Increase in breast size obtained by CAL lipoinjection is moderate, Dr. Yoshimura says, "but patients can achieve soft and natural-looking breasts without any concerns associated with foreign bodies."
A 33-year-old female patient who underwent breast augmentation immediately after implant removal. The patient, who had 210 mL saline implants, underwent CAL (260 mL in each breast). The preoperative view (top) showed capsular contractures and upward displacement of the left implant. At 12 months (bottom), the breasts were symmetric and had a natural appearance.
Dr. Yoshimura's belief in lipoinjection as a promising treatment led to his development of CAL, which attempts to minimize some of conventional lipotransfer's limitations, such as unpredictability and a low rate of graft survival due to fat necrosis.
In an early but pivotal study of 40 of his patients who underwent CAL for breast augmentation, Dr. Yoshimura found that final breast volume showed augmentation by 100 mL to 200 mL after a mean fat amount of 270 mL was injected.2
Postoperative atrophy of injected fat tissue was minimal and did not change substantially after two months, and he says, "almost all the patients were satisfied with the soft and natural-appearing augmentation."
Cyst formation or microcalcification was detected in four patients.
"The preliminary results suggest that CAL is effective and safe for soft-tissue augmentation and superior to conventional lipoinjection," Dr. Yoshimura says. The technique, he says, is a particularly good option for women who want to reduce excessive fat in other parts of the body. Additional studies are under way to further evaluate the efficacy of his technique.