Fat Grafts With Adipose-derived Regenerative Cells for Soft Tissue Reconstruction in Children

Fat Grafts Supplemented With Adipose-derived Regenerative Cells for Soft Tissue Reconstruction in Children With Craniofacial Microsomia

Although first reports of the clinical use of adipose-derived regenerative cells (ADRC) suggest that this approach may be feasible and effective for soft tissue augmentation, there is a lack of randomized, controlled clinical trials in the literature. Hence, this study aimed to investigate whether a novel protocol for isolation of ADRC and their use in combination with fat tissue improve the long-term retention of the grafts in paediatric patients with craniofacial microsomia.

To overcome problems associated with fat grafting, such as unpredictable clinical results and a low rate of graft survival, many innovative efforts and refinements of surgical techniques have been reported. For example, condensation of living tissue and removal of unnecessary components have been performed by centrifugation, filtration or gravity sedimentation; external mechanical force has been used to expand the recipient tissue as well as the overlying skin envelope; and a recent experimental study has suggested that repeated local injections of erythropoietin might enhance retention of grafted fat. Based on the finding that aspirated fat tissue contains a much smaller number of adipose-derived regenerative cells (ADRC) compared with intact tissue and that these cells play pivotal roles in the adipose tissue remodeling after lipoinjection, the supplementation of fat grafts with stromal vascular fraction isolated from adipose portion of liposuction aspirates has been proposed as a method to compensate its relative deficiency of ADRC. In the literature, there are at least three experimental studies demonstrating that supplementation of adipose progenitor cells enhances the volume or weight of surviving adipose tissue, and first reports of the clinical use of ADRC suggest that this approach may be feasible and effective for soft tissue augmentation. However, since these studies represent level of evidence IV, which correspond to the publication of case series, there is a lack of randomized, controlled clinical trials comparing this method to current standard techniques. Hence, this study aimed to fill this gap by investigating whether a novel protocol for isolation of ADRC and their use in combination with fat tissue improve the long-term retention of the grafts in paediatric patients with craniofacial microsomia.

Preoperative and 1, 3 and 6-months postoperative 3D-photogrammetry will be performed for volumetric measurements of both hemifaces using Vectra H1 software. Volumetric augmentation will be noticed for each patient by comparing the change between volumes of affected and unaffected hemifaces in the preoperative and 1, 3 and 6 months postoperative periods, which will be considered the retention volume. The percentage of fat graft survival will be determined as a ratio of the retention volume to the preoperative difference between volumes of affected and unaffected hemifaces.

Immediately after the surgical procedure the number of viable cells isolated before and after the supplementation of the grafts will be counted using the trypan blue dye exclusion assay in a Neubauer chamber using the light microscope Nikon Eclipse TS100 (Nikon Instruments Inc., NY, USA). Next, immunophenotype characterization of cell populations on passage 1 will be done by flow cytometric analysis with the anti-human antibodies CD29, CD31, CD45, CD90, CD73 and CD105 (Becton, Dickinson and Company, NJ, USA) in a Guava EasyCyte flow cytometer running the Guava Express Plus software (Guava Technologies Hayward, CA, USA).

Inclusion Criteria: Unilateral craniofacial microsomia 10 to 18 years old Phenotype: (M0, M1 or M2) and (S1 or S2) according to the OMENS-Plus classification Exclusion Criteria: Previous facial soft tissue surgery Absence of fat donor site