[Keloid treatment†: Where do we stand†?] / Traitement des chéloïdes: où en sommes-nous?

Keloids are debilitating skin lesions that develop often as a result of minor skin lesions. Unlike hypertrophic scars, their main clinical feature is the tendency to extend beyond the initial limits of the wound. They can be responsible for pain and itching and may appear several months after the trauma. Their pathophysiology remains unknown but various mechanisms seem to be involved. Their management includes invasive and non-invasive approaches. At present, there is no satisfactory method or consensus on their management. Since the risk of recurrence after treatment is particularly high, a combination of different methods is proposed. In this article, we present the therapeutic strategy used in our institution concerning these problematic lesions.

Les chéloïdes sont des lésions cutanées débilitantes se développant suite à un traumatisme cutané souvent mineur. Contrairement aux cicatrices hypertrophiques, leur principale caractéristique clinique est la tendance à envahir la peau saine et à s'étendre au-delà des limites initiales de la plaie. Elles peuvent être responsables de douleurs et démangeaisons et apparaître plusieurs mois après le traumatisme. Leur physiopathologie reste inconnue mais divers mécanismes semblent impliqués. Leur prise en charge comprend des approches invasives et non invasives. A l'heure actuelle, il n'y a pas de méthode satisfaisante ni de réel consensus concernant leur traitement. Le risque de récidive étant particulièrement élevé, une combinaison de différentes méthodes est proposée. Dans cet article, nous présentons la stratégie utilisée dans notre établissement concernant ces lésions complexes.

Long-Segment Tracheal Reconstruction With Free Radial Forearm Flap Reinforced by Rib Cartilage.

Long-segment tracheal reconstruction remains a challenge. The ideal tracheal substitute should be an epithelialized tube to prevent stenosis and sufficiently rigid to maintain airflow patency. An autologous technique using a radial forearm free flap reinforced by rib cartilage has been recently described for tracheal reconstruction. We report here two cases of complex tracheal reconstruction with a modification of this technique, which consists of the creation of two independent skin paddles to allow the reconstruction of the trachea and a second adjacent defect (eg, cervical skin, esophagus). Airway patency was achieved with no stenosis, prolonged stenting, fistula, or necrosis after 26 and 44 months, respectively. We suggest that the satisfactory outcome obtained with this modified technique is a valuable option for tracheal and adjacent defect reconstruction without the need for a second flap.

Reactive Oxygen Species and NOX Enzymes Are Emerging as Key Players in Cutaneous Wound Repair.

Our understanding of the role of oxygen in cell physiology has evolved from its long-recognized importance as an essential factor in oxidative metabolism to its recognition as an important player in cell signaling. With regard to the latter, oxygen is needed for the generation of reactive oxygen species (ROS), which regulate a number of different cellular functions including differentiation, proliferation, apoptosis, migration, and contraction. Data specifically concerning the role of ROS-dependent signaling in cutaneous wound repair are very limited, especially regarding wound contraction. In this review we provide an overview of the current literature on the role of molecular and reactive oxygen in the physiology of wound repair as well as in the pathophysiology and therapy of chronic wounds, especially under ischemic and hyperglycemic conditions.

Factors Associated With Treatment Failure of Infected Pressure Sores.

OBJECTIVE: In this study, we assess interdisciplinary surgical and medical parameters associated to recurrences of infected pressure ulcers. BACKGROUND: There is a little in the published literature regarding factors associated with the outcome of treatment of infected pressure ulcers. METHODS: We undertook a single-center review of spinal injured adults hospitalized for an infected pressure ulcer or implant-free osteomyelitis and reviewed the literature on this topic from 1990-2015. RESULTS: We found 70 lesions in 31 patients (52 with osteomyelitis) who had a median follow-up of 2.7 years (range, 4 months to 19 years). The median duration of antibiotic therapy was 6 weeks, of which 1 week was parenteral. Clinical recurrence after treatment was noted in 44 infected ulcers (63%), after a median interval of 1 year. In 86% of these recurrences, cultures yielded a different organism than the preceding episode. By multivariate analyses, the following factors were not significantly related to recurrence: number of surgical interventions (hazard ratio 0.9, 95% confidence interval 0.5-1.5); osteomyelitis (hazard ratio 1.5; 0.7-3.1); immune suppression; prior sacral infections, and duration of total (or just parenteral) antibiotic sue. Patients with antibiotic treatment for <6 weeks had the same failure rate as those with as >12 weeks (χ test; P = 0.90). CONCLUSIONS: In patients with infected pressure ulcers, clinical recurrence occurs in almost two-thirds of lesions, but in only 14% with the same pathogen(s). The number of surgical debridements, flap use, or duration of antibiotic therapy was not associated with recurrence, suggesting recurrences are caused by reinfections caused by other extrahospital factors.

Hyperbaric oxygen therapy promotes wound repair in ischemic and hyperglycemic conditions, increasing tissue perfusion and collagen deposition.

The treatment of chronic wounds remains inconsistent and empirical. Hyperbaric oxygen therapy (HBOT) is a promising method to improve wound repair but there is still a lack of understanding of its mechanisms of action and its indications are not yet clearly defined. We studied the effects of HBOT in four different wound conditions by inflicting bilateral wounds on the dorsal aspect of the feet of nonischemic or ischemic limbs in normoglycemic or hyperglycemic rats. To create an ischemic condition, arterial resection was performed unilaterally. Forty-four animals received HBOT five times a week until complete wound closure. Wound repair was compared with 44 rats receiving standard dressing only. HBOT increased blood flow and accelerated wound closure in ischemic and hyperglycemic wounds, most significantly when the two conditions were combined. Wound contraction and reepithelialization were similarly stimulated by HBOT. The acceleration of wound contraction was not associated with increased myofibroblasts expression, nor fibroblast recruitment or higher cell count in the granulation tissue. Of note, we observed a significant increase in collagen deposition in early time points in ischemic wounds receiving HBOT. This data emphasizes that an early application of HBOT might be crucial to its efficacy. We concluded that wounds where ischemia and hyperglycemia are combined, as it is often the case in diabetic patients, have the best chance to benefit from HBOT.

Local shockwave-induced capillary recruitment improves survival of musculocutaneous flaps.

BACKGROUND: Shockwave (SW) application has been shown to limit flap necrosis. However, the underlying microhemodynamic mechanisms remain unclear. Therefore, the objective of this study was to analyze the effect of SW application on a microcirculatory level. METHODS: We treated 12 C57BL/6 mice with local SW application (500 shockwave impulses at 0.15 mJ/mm(2)) either 24 h before (preconditioning [PRE]) or 30 min after (postconditioning [POST]) flap elevation. Animals with an untreated flap (CON) or without a flap served as controls. We applied dorsal skinfold chambers to the animals and performed epifluorescence microscopy over a 10-d period to assess microcirculatory parameters (arteriolar diameter, red blood cell velocity, blood flow, functional capillary density, and intercapillary distance) as well as inflammation, apoptotic cell death, and necrosis. RESULTS: SW application significantly decreased tissue necrosis independently of the application time point (PRE: 29% ± 7%; POST: 25% ± 7% versus CON: 47% ± 2%; day 10, P < 0.05). Arteriolar diameter, red blood cell velocity, and blood flow were not statistically significantly different among the 3 flap groups. However, SW (PRE and POST) resulted in an early and persistent increase in functional capillary density and consequently decreased intercapillary distance compared with CON and the group without a flap (P < 0.05). Also, SW resulted in a significantly decreased inflammatory response (P < 0.05) and induced an angiogenic response, as indicated by new functional microvessel formation observed 5 d after therapy. CONCLUSIONS: Local SW application improved tissue survival by recruitment of sleeping capillaries within the non ischemic tissue and maintenance of capillary perfusion within the critically perfused tissue after induction of ischemia, which was independent of the application time point. Neoangiogenesis occurred beyond the ischemic tolerance of the tissue, and therefore does not seem to contribute to improved tissue survival.

Proteus syndrome revealing itself after the treatment of a bilateral subdural haematoma.

INTRODUCTION: Hypertrophy of the calvarium has different aetiologies, among them the rare Proteus syndrome. CASE REPORT: We report here the case of a young girl initially treated for relapsing right then left large chronic subdural haematoma, who progressively developed craniofacial hypertrophy consistent with the diagnosis of Proteus syndrome. Calvarium hypertrophy was shaved and remodelled combining midface advancement, essentially for cosmetic purposes. During the first calvarium remodelling, important bleeding of the bone required large volume of blood replacement. Haemostasis workup revealed platelets aggregation anomalies. Bleeding issues during subsequent surgeries were controlled with tranexamic acid and desmopressin acetate. DISCUSSION: Other manifestations of Proteus syndrome, such as a right hypertrophy of the face with hypoplasia of its middle third, a pigmented epidermal nevus and asymmetric limbs and scoliosis, appeared progressively over time. Blood and fibroblast phosphatase and tensin homolog mutation was not found. CONCLUSION: Literature review of operated patients with Proteus syndrome did not reveal an association with platelets anomalies. A complete haemostasis workup following this unexpected haemorrhagic complication is recommended for this rare pathology.

NADPH oxidase 4 is dispensable for skin myofibroblast differentiation and wound healing.

Differentiation of fibroblasts to myofibroblasts is governed by the transforming growth factor beta (TGF-ß) through a mechanism involving redox signaling and generation of reactive oxygen species (ROS). Myofibroblasts synthesize proteins of the extracellular matrix (ECM) and display a contractile phenotype. Myofibroblasts are predominant contributors of wound healing and several pathological states, including fibrotic diseases and cancer. Inhibition of the ROS-generating enzyme NADPH oxidase 4 (NOX4) has been proposed to mitigate fibroblast to myofibroblast differentiation and to offer a therapeutic option for the treatment of fibrotic diseases. In this study, we addressed the role of NOX4 in physiological wound healing and in TGF-ß-induced myofibroblast differentiation. We explored the phenotypic changes induced by TGF-ß in primary skin fibroblasts isolated from Nox4-deficient mice by immunofluorescence, Western blotting and RNA sequencing. Mice deficient for Cyba, the gene coding for p22phox, a key subunit of NOX4 were used for confirmatory experiments as well as human primary skin fibroblasts. In vivo, the wound healing was similar in wild-type and Nox4-deficient mice. In vitro, despite a strong upregulation following TGF-ß treatment, Nox4 did not influence skin myofibroblast differentiation although a putative NOX4 inhibitor GKT137831 and a flavoprotein inhibitor diphenylene iodonium mitigated this mechanism. Transcriptomic analysis revealed upregulation of the mitochondrial protein Ucp2 and the stress-response protein Hddc3 in Nox4-deficient fibroblasts, which had however no impact on fibroblast bioenergetics. Altogether, we provide extensive evidence that NOX4 is dispensable for wound healing and skin fibroblast to myofibroblast differentiation, and suggest that another H2O2-generating flavoprotein drives this mechanism.

Management of unusual genital lymphedema complication after Fournier's gangrene: a case report.

BACKGROUND: Fournier's gangrene is a bacterial infection characterized by necrotizing fasciitis, skin and soft tissue involvement, and eventually myositis of the perineal region. Aggressive debridement of devitalized tissue and overlying skin is of paramount importance, but often leaves large defects to be reconstructed. The present case reports successful extensive perineal defects coverage following Fournier's gangrene and management of subsequent penile lymphoedema impairing sexual function in a young patient. CASE PRESENTATION: Following perianal abscess drainage, a healthy young man presented with scrotal pain. Fournier's gangrene was diagnosed and treated with multiple surgical debridements. Tissue excision extended through the entire perineal area, base of the penile shaft, lower abdominal region, the inner thighs, and gluteal region, corresponding to 12% of the total body surface area. After serial debridements and negative pressure dressings, the defect was covered by two stages of skin grafting. Graft take was 90%. Healing was achieved without hypertrophic or retractile scar. However, chronic penile lymphedema remained and was first treated with compressive garments for 2 years. Upon failure of this conservative approach, we performed a circumcision, but only a "penile lift" allowed a satisfactory esthetical and functional result. CONCLUSION: Fournier's gangrene can be complicated by a chronic lymphedema of the penis. Conservative treatment is likely to fail in severe cases and can be treated surgically by "penile lift".

Defining the Ideal Breast Reconstruction Procedure After Mastectomy From the Patient Perspective: A Retrospective Analysis.

Background: An increasing number of breast cancer patients undergo immediate or secondary breast reconstruction, but the ideal method in terms of patient satisfaction remains ambiguous. We compared the 3 most common breast reconstruction techniques to determine patient satisfaction and objective outcomes. Methods: Retrospective study of 184 patients with breast cancer who underwent a reconstructive procedure between 1993 and 2011 at our institution. Procedures evaluated were implant-based reconstruction (IBR) alone, latissimus dorsi (LD) flap reconstruction with/without implant, and deep inferior epigastric perforator (DIEP) free flap reconstruction. A retrospective patient satisfaction questionnaire was sent to all women. Twenty patients from each subgroup were matched to conduct a standardized objective assessment of the sensitivity of their reconstructed breast. A blinded photographic evaluation was also performed by 3 independent observers to assess the esthetic aspect and symmetry. Results: DIEP obtained significantly higher average scores regarding the esthetic outcome, immediate reconstruction impact, and overall score in the questionnaire evaluation. The IBR had the best results in the somatosensory evaluation, with DIEP scoring better than LD. DIEP received higher scores on average than LD for the criteria of size and symmetry in the esthetic evaluation. No statistically significant differences were observed between IBR and DIEP. Conclusions: Good results were reported overall for all breast reconstruction procedures, with more reserved scores for LD. The DIEP reconstruction appeared to be the most satisfactory and best experienced reconstruction method for patients, despite the complexity of the intervention. Clinicians should be encouraged to consider DIEP as the principal choice for breast reconstruction.

Operative Planning of Chest Wall Reconstructions Illustrated by a Large Defect in a Child.

Reconstruction of large chest wall defects is challenging. Here we discuss the process of decision-making in planning chest wall reconstruction, considering the requirements of tumor removal, stabilization of the chest wall, and soft tissue coverage, illustrated by a case of a hemi-chest wall defect in a child. Ewing sarcoma measuring 10 × 9 × 13 cm was resected in a 9-year-old boy, followed by stabilization using a Gore-Tex patch. Due to extension of the oncologic resection far into the superomedial quadrant of the chest, tension-free coverage with a classical latissimus-dorsi flap could not be achieved. Integrating the serratus-anterior muscle into the flap creating a chimeric latissimus-dorsi/serratus-anterior flap allowed for excellent soft tissue coverage of the foreign body. As the skin could be preserved, careful incision planning was necessary to allow for best possible exposure during oncologic resection and flap harvest, while ensuring skin vascularization impaired by underlying tumor resection. Two vertical skin incisions were chosen, one presternal and a second in the mid-axillary fold delineating a large bipedicled skin flap. Postoperative recovery was excellent. Solid skin vascularization and adequate soft tissue coverage of the alloplastic material allowed for the patient to receive two cycles of postoperative radiotherapy without developing wound dehiscence. Careful interdisciplinary planning of skin incisions allowed for good exposure for tumor resection and flap harvest while preserving skin vascularization. Choosing a chimeric latissimus-dorsi/serratus-anterior flap provided larger coverage than a classical latissimus-dorsi flap with minimal additional donor site morbidity. Taken together, we here present a pragmatic solution to a complex problem.

Transverse cervical vessels as a recipient site for microvascular reconstruction in vessel-depleted necks: a safe option.

BACKGROUND: Free flap reconstruction is the gold standard in complex head and neck reconstruction. The branches of the external carotid vessels (ECVs) are considered the most suitable recipients, but they may be unavailable in patients presenting "frozen necks" or "vessel-depleted necks" due to previous treatments. We report our experience using the transverse cervical vessels (TCV) in these situations. METHODS: Retrospective chart review of microsurgical head and neck reconstructions from 2005 to 2017. We focused our analysis on secondary procedures and compared the complication rate according to whether the TCV or the ECVs were used. RESULTS: A total of 97 free flaps were performed for secondary procedures in 89 patients, mainly due to oncological recurrence and fistulae. TCV were used in 14 procedures when external carotid vessel branches were unavailable. The overall complication rate (all grade III Dindo-Clavien) was of 21% versus 35%, respectively, in the TCV and ECVs group. Grade IIIb Dindo-Clavien complications, i.e., microsurgical complications (10%) and flap loss (1%), were only recorded in the ECVs group. Other complications recorded were seroma (7% versus 1%) and hematoma (17% versus 6%) in the TCV and ECVs groups, respectively, and corresponded to grade IIIa Dindo-Claviens. CONCLUSIONS: The use of TCV is a safe second-line recipient site for microsurgical head and neck reconstruction in vessel-depleted necks. Major advantages are their anatomical position outside the previous surgical and radiation zone, lower affinity for atherosclerotic damage, and similar diameter to the pedicles of the most used flaps.

[Multidisciplinary management of angiomas]. / Prise en charge multidisciplinaire des angiomes.

Angiomas are heterogenous vascular abnormalities, in terms of anatomy, biology and clinical course. Patients and families are often emotionally concerned. For all these reasons, a multidisciplinary approach is necessary in order to structure diagnostic and therapeutic work-up, and to ensure proper advice. The present paper summarizes contemporary classification of angiomas and presents some principles of multidisciplinary approach as it is applied for the past fifteen years at the University Hospitals of Geneva.

Fate of systemically and locally administered adipose-derived mesenchymal stromal cells and their effect on wound healing.

There is increasing interest in the use of adipose-derived mesenchymal stromal cells (ASCs) for wound repair. As the fate of administered cells is still poorly defined, we aimed to establish the location, survival, and effect of ASCs when administered either systemically or locally during wound repair under physiological conditions. To determine the behavior of ASCs, a rat model with wounds on the dorsal aspect of the hind paws was used and two treatment modes were assessed: ASCs administered systemically into the tail vein or locally around the wound. ASCs were transduced to express both firefly luciferase (Fluc) and green fluorescent protein to enable tracking by bioluminescence imaging and immunohistological analysis. Systemically administered ASCs were detected in the lungs 3 hours after injection with a decrease in luminescent signal at 48 hours and signal disappearance from 72 hours. No ASCs were detected in the wound. Locally administered ASCs remained strongly detectable for 7 days at the injection site and became distributed within the wound bed as early as 24 hours post injection with a significant increase observed at 72 hours. Systemically administered ASCs were filtered out in the lungs, whereas ASCs administered locally remained and survived not only at the injection site but were also detected within the wound bed. Both treatments led to enhanced wound closure. It appears that systemically administered ASCs have the potential to enhance wound repair distally from their site of entrapment in the lungs whereas locally administered ASCs enhanced wound repair as they became redistributed within the wound bed.

Monocyte chemoattractant protein-1 secreted by adipose tissue induces direct lipid accumulation in hepatocytes.

UNLABELLED: For many years, adipose tissue has been mainly considered as an inert reservoir for storing triglycerides. Since the discovery that adipocytes may secrete a variety of bioactive molecules (hormones, chemokines, and cytokines), an endocrine and paracrine role for white adipose tissue (WAT) in the regulation of energy balance and other physiological processes has been established, particularly with regard to brain and muscle. In contrast, little is known about the interactions of WAT with liver. Hence, we examined the effect of the secretory products of WAT on hepatocytes. Conditioned medium of human WAT explants induced significant steatosis in hepatocyte cell lines. Factor(s) responsible for the conditioned medium-induced steatosis were screened by a battery of blocking antibodies against different cytokines/chemokines shown to be secreted by WAT. In contrast to interleukin-8 and interleukin-6, the monocyte chemoattractant protein-1 was capable of inducing steatosis in hepatocytes in a time-dependent manner at concentrations similar to those found in conditioned medium. Incubation of conditioned medium with antimonocyte chemoattractant protein-1 antibodies prevented triglyceride accumulation. Investigation of the mechanism leading to the triglyceride accumulation showed that both a diminution of apolipoprotein B secretion and an increase in phosphoenolpyruvate carboxykinase messenger RNA may be involved. CONCLUSION: The monocyte chemoattractant protein-1 secreted by adipose tissue may induce steatosis not only recruiting macrophages but also acting directly on hepatocytes.

Autologous Platelet-Rich Plasma (CuteCell PRP) Safely Boosts In Vitro Human Fibroblast Expansion.

Nowadays autologous fibroblast application for skin repair presents an important clinical interest. In most cases, in vitro skin cell culture is mandatory. However, cell expansion using xenogeneic or allogenic culture media presents some disadvantages, such as the risk of infection transmission or slow cell expansion. In this study, we investigated an autologous culture system to expand human skin fibroblast cells in vitro with the patient's own platelet-rich plasma (PRP). Human dermal fibroblasts were isolated from patients undergoing abdominoplasty, and blood was collected to prepare nonactivated PRP using the CuteCell™ PRP medical device. Cultures were followed up to 7 days using a medium supplemented with either fetal bovine serum (FBS) or PRP. Fibroblasts cultured in medium supplemented with PRP showed dose-dependently significantly higher proliferation rates (up to 7.7 times with 20% of PRP) and initiated a faster migration in the in vitro wound healing assay compared with FBS, while chromosomal stability was maintained. At high concentrations, PRP changed fibroblast morphology, inducing cytoskeleton rearrangement and an increase of alpha-smooth muscle actin and vimentin expression. Our findings show that autologous PRP is an efficient and cost-effective supplement for fibroblast culture, and should be considered as a safe alternative to xenogeneic/allogenic blood derivatives for in vitro cell expansion. Impact Statement Autologous dermal fibroblast graft is an important therapy in skin defect repair, but in vitro skin cell culture is mandatory in most cases. However, cell expansion using xenogeneic/allogenic culture media presents some disadvantages, such as the risk of infection transmission. We demonstrated that an autologous culture system with the patient's own platelet-rich plasma is an efficient, cost-effective, and safe supplement for fibroblast culture. As it respects the good manufacturing practices and regulatory agencies standards, it should be considered as a potent alternative and substitute to xenogeneic or allogenic blood derivatives for the validation of future clinical protocols using in vitro cell expansion.

Sociodemographic Characteristics of Traditional Healers and Their Knowledge of Noma: A Descriptive Survey in Three Regions of Mali.

Background: Noma can be a lethal disease and causes disfigurement in young children in low-resource countries, particularly in Africa. In these settings, 80% of the population mainly consult traditional healers for healthcare problems. Our study aimed to describe the sociodemographic characteristics of traditional healers and to assess their knowledge of noma. Methods: We conducted a survey among traditional healers in three Malian regions from May 2015 to January 2016 and collected data on sociodemographic characteristics, professional activity, knowledge, and experience of noma and collaboration with modern medicine. Results: Among 770 traditional healers invited to participate, 732 responded (95%) (mean age, 54.5 years). Most were illiterate (66.3%), which was associated with older age (p < 0.001). Although they treated all types of disease, only 10.5% had some knowledge of noma, with regional differences (p < 0.001). Conclusion: Noma is poorly known among traditional healers, especially in remote areas. Our findings suggest a lack of interest among young people for traditional medicine, implying an imminent decrease of healers, and thus the need for national health systems to strengthen and promote access to modern health care. Training programmes to improve the early diagnosis referral of noma patients should include all types of primary health workers.

Management of median and paramedian craniofacial clefts.

BACKGROUND: Median and paramedian craniofacial clefts are associated with hypertelorism, anterior encephalocele, positional abnormalities of the maxilla, and nasal deformity. Cleft lip and palate, eyelid coloboma, and widow's peak are frequently present. METHODS: The authors collected data from 30 patients (mean age, 5.8 years; range, 4 months to 18 years) operated between 1986 and 2017 with median or paramedian craniofacial clefts of differing degrees of severity. Malformations of the different anatomic units and their surgical treatment were assessed, as well as complication rates. RESULTS: All patients presented nasal malformations and either telecanthus (n = 16) or hypertelorism (n = 14). Most patients (n = 23) had anterior encephalocele. All patients underwent nasal corrections, and most of them had medial canthopexy (n = 24). Excision of encephalocele was associated with fronto-orbital remodeling. Medialization of the orbits was performed in 11 patients, mainly by box shift (n = 9). Patients from outside Switzerland (n = 23) were operated at an older age than those in the native patient group. Because of staged reconstruction, 13 patients had more than one operation. Surgical complications included three infections and one expander exposition. One patient had bone resorption of a frontal bone flap. Nasal correction needed more than one procedure in 5 patients, and medial canthopexy had to be repeated in 7 patients. Esthetic results were satisfactory, permitting social integration. CONCLUSION: Median and paramedian craniofacial clefts need adapted and carefully planned corrections respecting the growth of anatomic units. The quality of the medial canthal and nasal reconstruction is to a large extent responsible for the overall result.

Does non-activated platelet-rich plasma (PRP) enhance fat graft outcome? An assessment with 3D CT-scan in mice.

BACKGROUND: The adjunction of autologous platelet-rich plasma (PRP) is emerging as a promising approach to enhance the long-term survival of fat grafting, but there are still insufficient data on its efficacy. The aim of this in vivo study was to assess the effect of the addition of non-activated PRP on fat graft outcome. METHODS: Human adipose tissue mixed with 20% of non-activated PRP was injected under the scalp skin of nude Balb/cAnNRj mice and compared to grafted fat mixed with 20% of saline. The fat graft volume was analyzed by a computed tomography scan until day 90 and immunohistochemistry was then performed to assess adipocyte viability and graft revascularization. RESULTS: At day 90, the volume of fat graft was not enhanced by PRP compared to the saline control group. However, immunohistochemistry showed that PRP significantly increased the fat graft area occupied by intact adipocytes compared to the saline group (72.66% vs. 60.78%, respectively; p < 0.05). Vascularity was also significantly higher in the PRP group compared to the control group (6695 vs. 4244 CD31+ cells/µm2, respectively; p < 0.05). CONCLUSION: The adjunction of non-activated-PRP to fat grafts significantly increased adipocyte viability and tissue vascularity. However, in contrast to other studies adding activated-PRP, non-activated-PRP did not increase residual fat graft volume until day 90. Further studies are therefore needed to understand whether PRP has a positive effect on fat graft volume. As 3D computed tomography scan is a reproducible and precise technique, it should be used to analyze fat graft volume changes over time.