# Non-Surgical Touch-Up with Hyaluronic Acid Fillers Following Facial Reconstructive Surgery
## 4 Discussion
Visual analog scale (VAS) was used to assess patient satisfaction 9 weeks after treatment; 100 represents the best possible aesthetic outcome and 0 the worst; 0–74: not satisfied; 75–79: fairly satisfied; 80–89: satisfied; 90–99: very satisfied; 100: extremely satisfied. In fact, recently, structural fat grafting has moved from pure aesthetic surgery to reconstructive, craniofacial, and regenerative medicine [26, 27]. In addition to providing volume augmentation and a natural filling effect, injected fat is supposed to have a regenerative ability that improves the texture of the overlying skin [46, 47, 48]. Furthermore, fat tissue has shown striking improvement of tissue texture quality, as well as biocellular regenerative potential, due to the large amount of mesenchymal stem cells obtained in the lipoapspirate [47]. The wide availability of adipose tissue combined with a straightforward mechanical protocol to process the fat tissue into a highly-concentrated solution of ADSC, brings regenerative surgery into reconstructive practice [27, 48]. However, even if its benefits are simplicity and minimal donor site morbidity, this procedure requires a harvest procedure, additional operative time in harvesting, and decanting phases. Nevertheless, the greatest challenge of structural fat grafting is in maintaining its viability: controversy exists in the literature regarding its durability and the long-term results of lipotransfer are still variable [49]. Furthermore, the fat could not resorb in a uniform fashion and may lead to asymmetries that may require additional procedures for correction [50]. The clinical success of the procedure is referred to the long-term volume maintenance, determined by the ability of the transplanted fat cells to both resist resorption over time and survive in the new environment [49, 51]. Various harvesting, preparation, and injection techniques have been proposed to improve fat graft survival [52, 53, 54]. However, to date, there is no standard approach with reproducible and predictable outcomes and this issue has led to debate over the ideal lipofilling approach [49, 50, 53]. Thus, the greatest challenge of fat grafting is in preserving its viability and controversy still exists in the literature, regarding stability and persistence of clinical augmentation with adipose transplants. It is noted that fat volume stabilizes at 3 to 4 months with a subsequent subtle decrease in volume for up to a year after the procedure [52]. The resorption rate reported in the literature ranges from 25% to 90% [55, 56, 57, 58, 59, 60]. However, a good result at 6 months was predictive of a lasting correction [61]. [PERSON] reported an average loss of 45% of the free fat implant by 1 year and emphasized the importance of a well-vascularized recipient site [55]. [PERSON] et al. [62] noticed a 55% loss at 6 months, with regular negligible decreases in volume between 9 and 12 months, as documented by magnetic resonance imaging. [PERSON] [63] noted that many of the fat cells are disrupted and the ADSC carried with the lipoapspirate repopulate the grafted areas. This could explain both the volume loss and the improvement of texture and volume in the same grafted areas. Current attempts to maximize fat graft amount survival and predictability of engraftment focus on harvesting techniques, fat purification, and infiltration techniques, maximizing the transplantation of ADSC [64, 65, 66]. Significant variables include depth and technique of placement, sample washing, syringe and cannula size, anesthesia, expertise in surgical harvesting approach, degree of overcorrection and donor site. [PERSON] et al. [67] analyzed fat cell survival clinically and concluded that insufficient revascularization of grafted adipose cells is one of the main reasons for graft fat resorption among all steps of the technique, such as the harvesting technique, the type of fat, recipient tissue, or internal pressure at the recipient area, which could impair successful engraftment.