Facial fat necrosis after autologous fat transfer possibly associated with SARS-CoV-2 vaccine.

A 52-year-old female patient developed facial fat necrosis presenting with cutaneous induration three weeks after minimal access cranial suspension (MACS) lift with autologous fat grafting from the abdomen. Given that the patient received the Moderna SARS-CoV-2 vaccine one week after surgery, we hypothesize that the former predisposed her to tissue ischemia leading to fat necrosis. Histological findings after biopsy were consistent with fat necrosis, which included marked dermal fibrosis with areas of focal fat necrosis, lipophages, multinucleated giant cells, and siderophages. It is our hope that documenting this rare development in literature may serve as encouragement for adverse effect reporting after the SARS-CoV-2 vaccine administration and may boost inspection and monitoring of other health consequences by regulating agencies.

The Effect of Processing Technique on Fat Graft Survival.

BACKGROUND: Wide variations in fat graft survival have been reported. The authors hypothesize that treating the adipose tissue on Telfa gauze creates a processed lipoaspirate with a more functional adipokine profile that improves fat graft survival. METHODS: Suction-assisted lipoaspirate was harvested from humans and was either processed by centrifugation, rolled on Telfa gauze, or left unprocessed. Progenitor cell populations were quantified and characterized by flow cytometry. Glycerol-3-phosphate dehydrogenase assay was used to measure the functional adipocytes. The lipoaspirates were grafted into (n = 45) wild-type mice and harvested to assess fat graft persistence. Vascular endothelial growth factor and platelet-derived growth factor-BB secretions were measured by enzyme-linked immunosorbent assay technique. RESULTS: Centrifuged lipoaspirate had a greater number of progenitor cells per gram of tissue than Telfa-processed and unprocessed lipoaspirate. However, Telfa-processed lipoaspirate had a greater number of functional adipocytes (0.104 U/ml) than centrifuged (0.080 U/ml) and unprocessed lipoaspirate (0.083 U/ml) on glycerol-3-phosphate dehydrogenase assay (p < 0.05). After 10 weeks of grafting, it had greater fat graft persistence (70.9 ± 6.2 percent) than centrifuged (56.7 ± 5.5 percent) and unprocessed lipoaspirate (42.2 ± 2.7 percent) (p < 0.05). It also maintained a greater secretion of vascular endothelial growth factor and platelet-derived growth factor-BB at weeks 1 and 2 than centrifuged and unprocessed lipoaspirate. Furthermore, CD31 staining demonstrated an increase in vascular density of the Telfa-processed lipoaspirate at week 2 compared with the centrifuged lipoaspirate (37 ± 1 percent and 14 ± 4 percent per high-power field; p < 0.05). CONCLUSIONS: Lipoaspirate processing technique has a significant impact on fat graft survival rate. Increasing the number of functional adipocytes by processing the fat on Telfa gauze may augment the secretion of angiogenic and mitogenic adipokines within the graft, thereby improving its survivability. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Expanding the Applications of the Profunda Artery Perforator Flap.

BACKGROUND: The profunda artery perforator free flap has not gained traction for nonbreast reconstruction, likely because of the presence of a proven workhorse in the anterolateral thigh flap. The authors believe that the profunda artery perforator flap offers similar coverage characteristics with the benefits of a medial donor site, a more consistent anatomy, and relatively easy dissection. The authors review their indications, technique, and outcomes in seven patients requiring eight free flap reconstructions. METHODS: The authors applied the use of the vertically oriented profunda artery perforator flap to both lower extremity and head and neck reconstructions in which an anterolateral thigh flap would normally have been used. Details reviewed include soft-tissue defect, perforator location, flap size, recipient vessel, and complications. RESULTS: Eight soft-tissue defects were covered with a vertically oriented profunda artery perforator flap in seven patients. Six reconstructions were for distal lower extremity and two were for head and neck reconstruction, both trauma and oncologic reconstructions. Flap sizes ranged from 40 to 92 cm. The pedicle length ranged from 7 to 10 cm. There were no partial or complete flap losses. One complication of seroma at the donor site requiring washout and closure was encountered. CONCLUSIONS: The profunda artery perforator flap is a safe and effective option for perforator-based free flap reconstruction with relative ease of harvest and an inconspicuous donor site. This flap offers an excellent alternative to the anterolateral thigh flap. In certain patient demographics, the profunda artery perforator flap should be considered as a primary option. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Optimizing Efficiency in Deep Inferior Epigastric Perforator Flap Breast Reconstruction.

BACKGROUND: The process of harvesting and performing microsurgical anastomosis in a deep inferior epigastric perforator (DIEP) flap for breast reconstruction can be a lengthy procedure, which could affect outcomes and patient safety. We hypothesize that the implementation of a high volume center, preoperative planning, and the adaptation of key intraoperative components will optimize the efficiency of perforator flap surgery for breast reconstruction. METHODS: A retrospective review of 68 consecutive patients who underwent 104 DIEP flaps for immediate or delayed breast reconstruction was performed. Standardized preoperative planning, including computed tomography/magnetic resonance imaging angiogram, operating room setup, and operative technique, was followed. The times of flap harvest, internal mammary vessel harvest, microsurgical anastomosis, flap inset, wound closure, and total length of procedure were reviewed as well as patient outcomes. RESULTS: The average length of surgery for a unilateral DIEP was 3 hours and 21 minutes and for a bilateral DIEP was 5 hours and 46 minutes. In bilateral DIEP flaps, a significantly longer operative time was noted in immediate (363 ± 14 minutes) compared to delayed (296 ± 17 minutes) (P < 0.05) reconstruction and between procedures performed by 1 surgeon (400 ± 29 minutes) versus 2 surgeons (326 ± 11 minutes) (P < 0.05). Interestingly, no significant difference in operative time was seen in DIEP flaps performed on patients with a body mass index (BMI) less than 30 (193 ± 7.6, 352 ± 17 minutes) versus a BMI greater than 30 (213 ± 11, 333 ± 14 minutes) in both unilateral and bilateral procedures, respectively. CONCLUSIONS: Efficiency is optimized by preoperative planning with computed tomography/magnetic resonance imaging angiogram, a dedicated operating room team, including 2 microsurgeons and a systematic approach for surgery. The BMI may not significantly affect the duration of surgery.

Metatarsal reconstruction with a fibular osteocutaneous flap: a novel approach utilizing virtual surgical planning.

SUMMARY: Craniofacial reconstruction remains the main application for virtual surgical planning (VSP). We present a case in which this technology was applied to reconstruct a bony defect of the first metatarsal bone from a gunshot injury. VSP was used to facilitate a 1-stage reconstruction with a fibular osteocutaneous flap. A template of the reconstructed bone was designed based on the virtual mirror-image, noninjured bone. Prefabricated cutting guides facilitated precise shaping of the vascularized bone accounting for location of perforators. Successful reconstruction of the metatarsal bone was achieved with excellent functional outcomes. We believe that VSP can be a valuable tool in reconstruction of metatarsal bones by facilitating precise intraoperative shaping and anatomic orientation of the vascularized flap and reducing flap ischemia and operative time.

Grading lipoaspirate: is there an optimal density for fat grafting?

BACKGROUND: Clinical results of fat grafting have been unpredictable. In this article, the authors hypothesize that centrifugation creates "graded densities" of fat with varying characteristics that influence lipoaspirate persistence and quality. METHODS: Aliquots of human female lipoaspirate (10 cc) were centrifuged for 3 minutes at 1200 g. The bloody and oil fractions were discarded. Subsequently, 1.0 cc of the highest density and lowest density fat was separated for lipoinfiltration or analysis. Highest density or lowest density fat grafted into adult FVB mice was harvested at 2 and 10 weeks to quantify short- and long-term persistence, respectively. Progenitor cell number and expression of vascular endothelial growth factor, stromal cell-derived factor-1α, platelet-derived growth factor, and adiponectin were analyzed by flow cytometry and enzyme-linked immunosorbent assay, respectively. RESULTS: Greater percentages of highest density fat grafts remain at 2 and 10 weeks after injection compared with lowest density fat grafts (85.4 ± 1.9 percent versus 62.3 ± 0.1 percent, p = 0.05; and 60.8 ± 4.9 versus 42.2 ± 3.9, p < 0.05, respectively). Highest density fractions contain more progenitor cells per gram than lowest density fractions (2.0 ± 0.2-fold increase, p < 0.01). Furthermore, concentrations of vascular endothelial growth factor, stromal vascular fraction, platelet-derived growth factor, and adiponectin are all elevated in highest density compared with lowest density fractions (34.4 percent, p < 0.01; 34.6 percent, p < 0.05; 52.2 percent, p < 0.01; and 45.7 percent, p < 0.05, respectively). CONCLUSIONS: Greater percentages of highest density fractions of lipoaspirate persist over time compared with lowest density fractions. A vasculogenic mechanism appears to contribute significantly, as highest density fractions contain more progenitor cells and increased concentrations of several vasculogenic mediators than lowest density fractions.

Obesity impairs wound closure through a vasculogenic mechanism.

Since obesity impairs wound healing and bone marrow (BM)-derived vasculogenic progenitor cells (PCs) are important for tissue repair, we hypothesize that obesity-impaired wound healing is due, in part, to impaired PC mobilization, trafficking, and function. Peripheral blood was obtained from nondiabetic, obese (BMI > 30, n = 25), and nonobese (BMI < 30, n = 17) subjects. Peripheral blood human (h)PCs were isolated, quantified, and functionally assessed. To corroborate the human experiments, 6-mm stented wounds were created on nondiabetic obese mice (TALLYHO/JngJ, n = 15) and nonobese mice (SWR/J, n = 15). Peripheral blood mouse (m)PCs were quantified and wounds were analyzed. There was no difference in the number of baseline circulating hPCs in nondiabetic, obese (hPC-ob), and nonobese (hPC-nl) subjects, but hPC-ob had impaired adhesion (p < 0.05), migration (p < 0.01), and proliferation (p < 0.001). Nondiabetic obese mice had a significant decrease in the number of circulating PCs (mPC-ob) at 7 (p = 0.008) and 14 days (p = 0.003) after wounding. The impaired circulating mPC-ob response correlated with significantly impaired wound closure at days 14 (p < 0.001) and 21 (p < 0.001) as well as significantly fewer new blood vessels in the wounds (p < 0.001). Our results suggest that obesity impairs the BM-derived vasculogenic PC response to peripheral injury and this, in turn, impairs wound closure.

Flow perfusion maintains ex vivo bone viability: a novel model for bone biology research.

Encased in lacunae, osteocytes receive nutrition and biomechanical signals through the lacunocanalicular system. We have developed a novel flow-perfusion bioreactor designed to support lacunocanalicular fluid flow. We hypothesize that ex vivo fluid flow can maintain endochondral bone viability and, ultimately, serve as a novel model to study bone biology in vitro. Sprague-Dawley rat femurs were harvested, stripped of soft tissue, loaded into a custom-designed bioreactor and perfused with osteogenic culture medium. After 14 days of flow-perfusion or static culture, the bones were harvested, fixed, decalcified, embedded, sectioned and stained with haematoxylin and eosin. Fresh long bone samples were similarly processed for comparison. Osteocyte viability and function were also evaluated, using thiazolyl blue tetrazolium bromide (MTT), fluorospectrophotometric DNA quantification, alkaline phosphatase (ALP) colorimetric assay and fluorochrome labelling of mineralizing surfaces. All samples remained free of infection throughout the study period. After 14 days of flow perfusion, histological analysis showed normal-appearing bony architecture, with 72% of lacunae being osteocyte-filled compared with 93% in freshly harvested samples and only 36% in static samples. MTT staining and assay confirmed osteocyte viability in the flow-perfusion samples as well as in fresh samples. DNA quantification demonstrated DNA to be preserved in flow-perfused samples when compared with freshly harvested samples. ALP activity in flow-perfusion explants was upregulated compared with fresh and static samples. Fluorochrome-labelled mineralizing surfaces were seen throughout the explanted flow-perfused samples. This is the first demonstration that flow perfusion provides adequate chemotransportation to explanted murine endochondal bones.

Augmenting neovascularization accelerates distraction osteogenesis.

BACKGROUND: Distraction osteogenesis has revolutionized the treatment of craniofacial deformities, but it is limited by lengthy consolidation periods and tenuous healing in certain clinical settings, such as irradiated tissue. In this study, the authors aim to investigate whether increasing neovascularization by progenitor cell mobilization accelerates bone formation during distraction. METHODS: Sprague-Dawley rats aged 8 weeks (n = 36) were subjected to unilateral mandibular distraction with 3-day latency, 7-day activation (0.25 mm twice daily), and 21-day consolidation periods. From the beginning of the consolidation period, animals received daily injections of either AMD3100 (bone marrow progenitor cell mobilizing agent) or sterile saline. Animals were euthanized on postoperative day 31; mandibles were harvested; and bone regeneration was assessed using micro-computed tomography, immunohistochemistry, bone morphogenetic protein-2 enzyme-linked immunosorbent assay, and mechanical testing. RESULTS: Immunohistochemistry demonstrated that AMD3100 treatment increased vascular density and bone formation. Micro-computed tomography and dual-emission x-ray absorptiometry demonstrated that AMD3100-treated animals had improved bone generation compared with sham-treated controls. Greater force was required on three-point testing to break AMD3100-treated bone. Bone morphogenetic protein-2 expression was up-regulated with AMD3100. Interestingly, the nondistracted contralateral hemimandibles treated with AMD3100 were also stronger than sham-treated counterparts. CONCLUSIONS: Progenitor cell mobilization improves bone regeneration in a rat distraction model. Furthermore, because this effect is seen in healthy bone and in ischemic bone healing during distraction, the mechanism is not merely related to oxygenation, but could be a phenomenon of fluid flow.

Human fat grafting alleviates radiation skin damage in a murine model.

BACKGROUND: Autogenous fat grafting has been observed to alleviate the sequelae of chronic radiodermatitis. To date, no study has replicated this finding in an animal model. METHODS: The dorsa of adult wild-type FVB mice were shaved and depilated. The dorsal skin was then distracted away from the body and irradiated (45 Gy). Four weeks after irradiation, 1.5-cc fat or sham grafts were placed in the dorsal subcutaneous space. Gross results were analyzed photometrically. The animals were euthanized at 4 and 8 weeks after fat or sham grafting and their dorsal skin was processed for histologic analysis. RESULTS: Hyperpigmentation and ulceration were grossly improved in fat-grafted mice compared with sham-grafted controls. This improvement manifested histologically in a number of ways. For example, epidermal thickness measurements demonstrated decreased thickness in fat-grafted animals at both time points (20.6 ± 1.5 µm versus 55.2 ± 5.6 µm, p = 0.004; 17.6 ± 1.1 µm versus 36.3 ± 6.1 µm, p = 0.039). Picrosirius red staining demonstrated a diminished scar index in fat-treated animals at both time points as well (0.54 ± 0.05 versus 0.74 ± 0.07, p = 0.034; and 0.55 ± 0.06 versus 0.93 ± 0.07, p = 0.001). CONCLUSION: Fat grafting attenuates inflammation in acute radiodermatitis and slows the progression of fibrosis in chronic radiodermatitis.