A fast neovascularisation of grafted tissue is a significant parameter for cellular survival and limits tissue resorption. By offering matricial support to angiogenesis, and by stimulating the proliferation of pre-adipocytes, platelet-rich fibrin has a beneficial role to play in the cicatrisation and consolidation of an adipocyte graft. Modern studies show the interest in platelet-rich fibrin during aesthetic lipostructure. The potential uses in plastic surgery of such a biomaterial, easy and fast to produce, with minimal risk, are vast, but require further testing and methodical evaluation.

Facial rejuvenation by filling the tissue can be a challenge. The aim is to restore harmonious volumetric facial ratios by regaining the contours of cheekbones, drooping jaw lines and nasolobial folds. Fat grafts can return the skin to a state of brightness and volume, which are known to gradually deteriorate during the ageing process.

To ensure that a tissue graft remains stable, it must be integrated into the receiver site. This integration has to take place in the form of a matrix and tissue fusion, as with all living tissue. It has always been problematic for fat grafts to induce the necessary neoangiogenesis, which subsequently had significant resorption. Non-resorbable, exogenic materials (e.g. silicone) were introduced as early as the 1950s for implantation, but suspended years later owing to harmful effects such as migration and granuloma. Hyaluronic acid-based dermal fillers and other formulations are popular, but absorb quickly and large volumes present cost issues.

Background

The use of fat grafts for tissue filling is not a new method, but actually dates back to 1889 when Van der Muelen described the first use of fat in human autotransplantation, closely followed by Neuber in 1893, who first carried out free fat grafts in humans, in which a number of small grafts were used to fill a soft depression in the face of a 20-year-old man .

With regard to aesthetic medicine, the first report was published by Lexer in 1910.The most recent pioneers in the development of fat grafting for aesthetic purposes were Illouz (liposuction) in 19831 and Fournier (liposculpture) in 19852.

However, the reference point for the fat grafting technique was described by the American plastic surgeon Sydney Coleman3, 4, which also deals with the problem of resorption. The grafted fat tissue is centrifuged before reinjection, meaning that it can be sufficiently broken apart without damaging the adipocytes to stimulate the neosynthesis of an extracellular matrix and facilitate the colonisation of the graft by endothelial cells. This centrifugation stimulates the preadipocytes, cells allowing the reconstruction of the grafted tissue. Dr Coleman’s technique requires the decomposition of pre-existent tissue to allow its reconstruction in situ.

Mode of action

Growth-inducing agents to improve the sustainability of adipocyte grafts have never really been developed. The grafted adipocytes, being differentiated, are not sensitive to the causes of proliferation likely to be induced by these molecules. The main clinical protocols, which make it possible to use autogenous growth-inducing agents, are generally part of the platelets’ concentrated family.

The platelets used in oral, maxillofacial and plastic surgery are generally grouped as concentrated platelet-rich plasma (cPRP). According to the literature, many preparation and treatment protocols exist, but they are all supported by specific methods originating from fibrin glues, which are not uncommon in plastic surgery5–17. The general principle of production comprises a double centrifugation, making it possible to eliminate red blood cells, then acellular plasma, to preserve only the concentrated platelets. Bovine thrombin (with calcium chloride) is generally used to make PRP, in the same way as making a simple fibrin adhesive.

Figure 1 (A) 60-year-old patient before bilateral facial lipostructure with platelet-rich fibrin, (B) 2 months after treatment, and (C) 8 months postoperatively

Figure 1 (A) 60-year-old patient before bilateral facial lipostructure with platelet-rich fibrin, (B) 2 months after treatment, and (C) 8 months postoperatively

The clinical effects of PRP are not hugely different to those usually produced by fibrin adhesives, suggesting that perhaps a fibrin matrix is more effective than the platelets’ cytokines, and are greatly loosened in this biological adhesive. Other than this adhesive effect, it has a proficient haemostatic effect on the diffused bleeding of the parenchyma, and reduces pain and postoperative oedema, resulting in a better angiogenesis induced by the fibrin matrix.

For medico–legal reasons of blood handling, PRP protocols have not been developed in France. The platelet-rich fibrin (PRF) technique developed by Choukroun et alis used18. The PRF technique is simple: blood is taken without anticoagulant from a 10 ml tube and then centrifuged directly using moderate forces (400 g). In the centre of the tube, a PRF clot is formed, containing most of the tube’s platelets and leukocytes. The clot can be used as a filling material; it can be cut into small pieces and mixed with a graft (usually with osseous grafts), or it can be pressed between two swabs, removing the serum to preserve the membranes (used in oral surgery and tympanoplasties).

When mixed with an osseous graft, PRF is used as a biological bond of the grafted particles, and the fibrin matrix leads to the vascularisation of the graft. The author took this a step further and mixed the PRF with another type of graft to maintain it in situ — without resorption. The first experiment resulted in a positive effect of the PRF on the proliferation of cultivated preadipocytes. The mature adipocytes are not as sensitive to the cykotine platelets, but the incorporation of fibrin clots to the fat mass allowed for a better graft vascularisation.