Fibroblast Growth Factor 9 Inhibited Apoptosis in Random Flap via the ERK1/2-Nrf2 Pathway to Improve Tissue Survival.

BACKGROUND: The application of random pattern skin flaps is limited in plastic surgery reconstruction due to necrosis. Fibroblast growth factor 9 (FGF9) was reported to exert a protective effect against myocardial damage and cerebral ischemia injury, but the impact of FGF9 in random flap survival is still unclear. In this study, we used a mouse model of random flaps to verify that FGF9 can directly increase flap survival area and blood flow intensity by promoting angiogenesis. MATERIALS AND METHODS: In total, 84 male C57BL/6 mice weighing between 22 and 25 g were randomly divided into three groups (n = 28 each group). After skin flap operation, one group served as a control, a treatment group received FGF9, and a treatment group received FGF9+U0126. All flap samples were incised on postoperative day 7. RESULTS: Our results showed that flap survival was significantly increased in the FGF9 group compared with that in the control group. This protective function was restrained by U0126. The results of histopathology, laser Doppler, and fluorescent staining all showed significant increases in capillary count, collagen deposition, and angiogenesis. FGF9 also significantly increased the expression of antioxidant stress proteins SOD1, eNOS, HO-1, vascular marker proteins CD31, VE cadherin, and pericyte marker protein PDGFRß. Western blot showed that the phosphorylation degree of ERK1/2 increased after FGF9 treatment, and the expression of Nrf2, a downstream factor, was u-regulated. Western blot and immunofluorescence results of apoptosis-related proteins cleaved caspase-3, BAX, and Bcl2 showed that FGF9 inhibited apoptosis. ERK inhibitor U01926 reduced the beneficial effects of FGF9 on skin flap survival, including promoting angiogenesis, and showing antiapoptosis and antioxidative stress activities. CONCLUSIONS: Exogenous FGF9 stimulates angiogenesis of random flap and survival of tissue. the impact of FGF9 is closely linked to the prevention of oxidative stress mediated by ERK1/2-Nrf2. In the function of FGF9 in promoting effective angiogenesis, there may be a close interaction in the FGF9-FGFR-PDGFR-ERK-VE cadherin pathway. In particular, PDGFR and VE cadherin may interact.

Sinomenine promotes flap survival by upregulating eNOS and eNOS-mediated autophagy via PI3K/AKT pathway.

Large skin defects and surgical tissue reconstructions are frequently covered utilizing random flaps. The flap has the advantage of being designed according to the size and shape of a surgical wound. However, the necrosis of the distal part of the flap restricts the clinical application of flaps. Sinomenine (SIN) is the major active component of sinomenium acutum. SIN has been demonstrated to inhibit oxidative stress and stimulate autophagy in a cell, animal, and clinical studies. The protective and proliferative effects of sinomenium on HUVECs were evaluated by scratched test, CCK-8, and EDU assays. For the flap survival, we established a mouse random pattern flap model and observed the effects of SIN injected intraperitoneally. The survival area and blood flow intensity of the flap in sinomenium group were significantly increased compared to the control group. Our results demonstrate that SIN promotes flap survival. Sinomenium enhances eNOS expression in the flap and reduces the level of oxidative stress, promotes autophagy flux increase, reduces apoptosis, and promotes angiogenesis. Having a therapeutic benefit of SIN, Autophagy inhibitor 3-MA shows its critical role by reversing the beneficial effects of SIN, and the nitric oxide synthase inhibitor l-NAME both stimulated HUVECs that explore the relationship between autophagy flux and nitric oxide synthase. Furthermore, the mechanism in our study reveals the changes in the signal pathway of PI3K/AKT, the protective effect of SIN during antioxidant activity, the activation of eNOS through PI3K/AKT signaling pathway affects autophagy through the eNOS system, and promote the random flap survival.

Management of a Bronchopleural Fistula After Right-Sided Lobectomy Using a Delayed Random Flap Under Guidance of Indocyanine Green (ICG) Angiography: A Case Report.

Bronchopleural fistula (BPF) following lung resection and thoracic surgery is associated with high rates of morbidity and mortality. Various methods are available for the closure of BPF and thoracic dead space, including flap procedures and thoracoplasty. While delayed random flaps have been used for the treatment of BPF and closure of thoracic dead space, no previous reports have described the concurrent use of laser-assisted indocyanine green angiography (ICG-A). We report a case of successful BPF closure with a random delayed fasciocutaneous flap using laser-assisted ICG-A guidance for flap delay.

Local Random Flaps for the Diabetic Foot.

Diabetic foot wounds should be treated in a timely fashion to prevent infection and potential limb loss. When local wound care and traditional off-loading fails, surgeons may consider local random flaps for definitive closure. Wound size, location, and type are characteristics that should be considered for selection of the best flap. This article reviews the application of local random flaps in the treatment of diabetic foot wounds.

Notoginseng Triterpenes Inhibited Autophagy in Random Flaps via the Beclin-1/VPS34/LC3 Signaling Pathway to Improve Tissue Survival.

Random flaps are widely used in tissue reconstruction, attributed to the lack of vascular axial limitation. Nevertheless, the distal end of the flap is prone to necrosis due to the lack of blood supply. Notoginseng triterpenes (NTs) are the active components extracted from Panax notoginseng, reducing oxygen consumption and improving the body's tolerance to hypoxia. However, their role in random flap survival has not been elucidated. In this study, we used a mouse random skin flap model to verify that NT can promote cell proliferation and migration and that increasing blood perfusion can effectively improve the survival area of a skin flap. Our study also showed that the autophagy of random flaps after NT treatment was activated through the Beclin-1/VPS34/LC3 signaling pathway, and the therapeutic effect of NT significantly decreased after VPS34 IN inhibited autophagy. In conclusion, we have demonstrated that NT can significantly improve the survival rate of random flaps through the Beclin-1/VPS34/LC3 signaling pathway, suggesting that it might be a promising clinical treatment option.

Local random flaps for cervical circumferential defect or tracheoesophageal fistula reconstruction after failed gastric pull-up: Two case reports.

BACKGROUND: Total pharyngo-laryngo-esophagectomy with a reconstruction of gastric pull-up is the most common treatment method for patients with multiple primary upper digestive tract carcinomas, such as hypopharyngeal carcinoma with thoracic esophageal carcinoma. However, neck circumferential defect and tracheoesophageal fistula after gastric necrosis are still challenging problems for surgeons and patients. CASE SUMMARY: This case report presents 2 patients who underwent reconstructive surgeries using 4 local random flaps with a split thickness skin graft in the first case, and 6 local random flaps in the second case to close the circumferential defect and tracheoesophageal fistula after failed gastric pull-up. Both patients achieved good swallowing function and could take solid diet without dysphagia postoperatively. CONCLUSION: For selected patients, local random flaps (with a split thickness skin graft) can be a simple and reliable solution for reconstructing tracheoesophageal fistula or cervical circumferential defect after gastric necrosis, especially when the necrosis extends below the thoracic inlet.

"Pingpong racket" flap model for evaluating flap survival.

BACKGROUND: Random skin flap is widely used to repair tissue defects; however, it is often accompanied by ischemia and necrosis of the distal flap due to inferior axial vascularity. Even though different drugs, biomaterials, and stem cell therapies have been developed to improve the survival of random flap, evaluating the promotion of flap survival remains a big challenge. Based on successful clinical practice, we designed a "Pingpong racket" shape flap in the rat. Without the predetected blood vessels procedure, the "pingpong racket" flap provides a preferable option to evaluate the function of drugs and biomaterials in promoting flap survival. MATERIALS AND METHODS: "Pingpong racket" dorsal flaps with different pedicle lengths were developed in the rats. The survival area was evaluated by digital photography and computer-assisted analysis. The quantitative survival area was considered a useful indicator for analyzing drugs' applicability in improving skin flap survival. RESULTS: A new model with a pedicle width of 1 cm and a flap diameter of 3 cm, in which the length of the pedicle could be tuned, was established. No iliolumbar vessels passed through the pedicle. The necrosis ratio ( round ) of the flap was 29.88% in the 2 cm long pedicle, 74.69% in the 3 cm long pedicle, 95.52% in the 4 cm long pedicle, and in the 5 cm long pedicle; necrotic area could be found in both the round part and in the pedicle. CONCLUSION: The new 3 cm long pedicle flap is suitable for evaluating the drugs for promoting skin flap survival. Rat dorsal "Pingpong racket" flap can be easily handled, thus avoiding blood vessels' detection. The flap could achieve comparable results to clinical and alleviate the negative influence of the flap's longitudinal contraction. Besides, it is intuitive and aesthetically pleasing.

[Brief introduction of perforator flap].

In 600 BC, the first pedicled direct cutaneous artery perforator flap-the supravicular artery perforator flap was harvested by Sushruta. In 1973, the first free perforator flap-the superficial circumflex iliac artery flap in the groin was reported by Daniel and Taylor. In 1982, the septocutaneous perforator flap was reported by academician Zhong Shizhen. In 1989, the misculocutaneous perforator flap was reported by Koshima. Reviewing the history of flap surgery, there was a fact that the main evolutionary line was the course of perforator flap. In the future, the clinical application of the traditional random flap (reticulated blood supply flap) and traditional axial flap will be more and more less, whereas the clinical application of perforator flap, especially the direct cutaneous perforator flap and the special type of perforator flap will be more and more extensive.

Effects and mechanism of urinary kallidinogenase in the survival of random skin flaps in rats.

OBJECTIVE: This study explored the effects of urinary kallidinogenase (UK) on ischemia and necrosis of random skin flaps in rats, and the mechanisms thereof. METHODOLOGY: Ischemia and necrosis of random skin flaps were induced by constructing a modified McFarlane flap model on the dorsa of rats. UK (0.016 PNA/kg) or normal saline (10 ml/kg, control) was administered through the tail vein immediately after flap ischemia model construction and then daily for 7 days. After sacrifice, the flap tissue was harvested and stained with hematoxylin and eosin (H&E), and histopathological changes were observed. Lead oxide/gelatin angiography and laser Doppler imaging were performed to demonstrate angiogenesis and changes in blood flow. Immunohistochemical analysis of the H&E-stained slices was performed to detect the expression of vascular endothelial growth factor (VEGF), interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α (TNF-α). The TNF-α and IL-6 levels were also detected by enzyme-linked immunosorbent assays. The activity of superoxide dismutase (SOD) and the malondialdehyde (MDA) content were measured to represent the oxidative damage level. RESULTS: UK significantly alleviated ischemia and necrosis of random skin flaps, as evidenced by improved general results and histopathological manifestations, and markedly increased the mean survival area. UK prompted angiogenesis, increased blood flow and VEGF expression. The levels of TNF-α, IL-6, and IL-1ß were declined. Furthermore, UK increased SOD activity and decreased MDA content, suggesting that it has the capacity to alleviate oxidative damage. CONCLUSION: These findings suggest that UK sufficiently attenuated flap ischemia and increased the survival of random skin flaps in rats.

Subdermal nitrous oxide delivery increases skin microcirculation and random flap survival in rats.

Random skin flaps are essential tools in reconstructive surgery. In this study, we investigated the effect of subdermal nitrous oxide (N2O) application on random flap survival. In this experimental study, we used 21 female rats in three groups. In the N2O and air groups, gases were administrated under the proposed dorsal flap areas daily for seven days. Following the treatment period, flaps were raised and inserted back into their place from the dorsal skin. In the control group, the flaps were elevated and inserted back to their place without any pretreatment. Calculation of necrotic flap areas, histological examination and microangiography was performed to evaluate the results 7 days after the flap surgery. The average of necrotic flap area in the N2O, air and control group was 13.45%, 37.67% and 46.43%, respectively. (N2O vs air p = .044; N2O vs control p = .003). The average number of capillary formations identified in the histological analysis was 7.0 ± 1.58, 3.75 ± 2.36 and 4.4 ± 0.54 in the N2O, air and control group, respectively. (N2O vs air p = .017; N2O vs control p = .037). The average number of capillary structures identified in the angiography images were 6.3 ± 1.52, 1.6 ± 1.15 and 1.3 ± 0.57 in the N2O, air and control group, respectively. (N2O vs air p = .04; N2O vs control p = .02). We conclude that subdermal N2O application increases random flap survival through an increase in the skin microcirculation and could be promising for future clinical applications.

Effect of different frequency hyperbaric oxygen preconditioning on ischemia-reperfusion injury of rat flap after transplantation / 中华整形外科杂志

Objective@#To explore the effect of hyperbaric oxygen preconditioning with different frequency on the survival rate of flap and ischemia-reperfusion injury in rats after transplantation, and to explore the best preconditioning conditions to improve the survival rate of rat flaps after transplantation.@*Methods@#Thirty-six Sprague Dawley rats were randomly divided into four groups according to the random number table method, 9 groups in each group.Four groups of rats were pretreated with hyperbaric oxygen pretreatment for 0, 2, 4, and 6 days before the operation, control group, pretreatment 2 d group, pretreatment 4 d group, and pretreatment 6 d group. Taking the midline of the back of the rat as the axis, an ultra-long random flap with a pedicle at the tail end and about 1 cm from the superior iliac spine was designed and cut to a size of 10.0 cm×2.5 cm. The survival of the flaps in each group was observed and the final survival area and survival rate of the flaps were measured on the 7th day after surgery. On the 7th day after operation, the tissue was taken at a distance of 5 cm from the pedicle, and the histopathology was observed; The content of superoxide dismutase (SOD) and malondialdehyde (MDA) in flap tissue was detected by immunohistochemistry, and the expression rate of positive cells in each group was calculated. Immunofluorescence was used to detect the expression of interleukin-6 (IL-6) in the flap tissue.@*Results@#On the 7th day after the operation, the survival area and survival rate of the transplanted flaps in the hyperbaric oxygen pretreatment group were significantly higher than those in the control group (P<0.05), and the pretreatment 4 d and 6 d groups were significantly higher than the pretreated 2 d group (P<0.05), but there was no significant difference between the pretreated 4 d group and the 6 d group (P=0.095). Pathological observation on the 7th day after operation showed that there was some necrosis in the control group, the vascular cells in the pretreated 2 d group had more vascular structures, and more neovascularization was observed in the pretreated 4 d group. The inflammatory cells were the least in the 6 d pretreatment group, and the neovascularization was the same as the pretreatment 4 d group. The absorbance A value of SOD in the control group was 0.009 7±0.000 3, and the positive expression rate was 20%, which was significantly lower than that in the hyperbaric oxygen pretreatment group. The difference was statistically significant (P<0.05). However, the absorbance A value of MDA in the control group was 0.055 1±0.003 0, and the positive expression rate was 55%, which was significantly higher than that in the hyperbaric oxygen pretreatment group. The difference was statistically significant (P<0.05). Among them, the SOD absorbance A value of the pretreated 2 d group was 0.023 8±0.003 0, and the positive expression rate was 30%, which was lower than the pretreatment 4 d group (absorbance A value 0.046 9±0.003 0, positive expression rate 35%) and 6 d group (absorbance A value 0.047 2±0.003 6, positive expression rate 40%), The MDA absorbance A value of the pretreated 2 d group was 0.037 2±0.003 2, and the positive expression rate was 30%, which was higher than the pretreatment 4 d group (absorbance A value 0.014 7±0.002 4, positive expression rate 5%) and 6 d group (absorbance A value 0.017 0±0.001 8, positive expression rate 10%), the difference was statistically significant (P<0.05). However, there was no significant difference in the expression of SOD and MDA between the pretreated 4 d group and the pretreated 6 d group (P>0.05). The expression of IL-6 in the hyperbaric oxygen pretreatment group was significantly lower than that in the control group (absorbance A value 44.937 0±0.594 0), the difference was statistically significant (P<0.05). The absorbance A value in the pretreated 2 d group was 41.698 0±0.724 0, which was significantly higher than the pretreatment 4 d group (absorbance A value 34.049 0±0.323 0) and 6 d group (absorbance A value 33.524 0±0.639 0). The difference was statistically significant (P<0.05). There was no significant difference in the expression of the pretreated 4 d group compared with the 6 d group (P=0.068).@*Conclusions@#Hyperbaric oxygen preconditioning can significantly promote the survival of rat flaps after transplantation. Preoperative hyperbaric oxygen preconditioning once daily for 4 consecutive days, can enhance the tolerance of flap tissue to ischemia and anoxia and reduce tissue ischemia-reperfusion injury.

Brief introduction of perforator flap / 中华烧伤杂志

In 600 BC, the first pedicled direct cutaneous artery perforator flap—the supravicular artery perforator flap was harvested by Sushruta. In 1973, the first free perforator flap—the superficial circumflex iliac artery flap in the groin was reported by Daniel and Taylor. In 1982, the septocutaneous perforator flap was reported by academician Zhong Shizhen. In 1989, the misculocutaneous perforator flap was reported by Koshima. Reviewing the history of flap surgery, there was a fact that the main evolutionary line was the course of perforator flap. In the future, the clinical application of the traditional random flap (reticulated blood supply flap) and traditional axial flap will be more and more less, whereas the clinical application of perforator flap, especially the direct cutaneous perforator flap and the special type of perforator flap will be more and more extensive.

Random flap survival with hyperbaric oxygen: daily versus twice-daily treatments.

PURPOSE: Hyperbaric oxygen (HBO2) therapy is used to improve the survival of compromised flaps. Compromised flaps are complications encountered postsurgically, or in traumatic degloving or avulsion injuries. Failed flaps lead to persistence of the defect, requirement of another donor site, and psychosocial sequelae. Although evidence of the benefit of HBO2 therapy is significant, there is no consensus on the optimal treatment regimen. The purpose of this study is to examine whether twice-daily treatments (BID HBO2) provide additional benefit compared to daily treatments (QD HBO2) in a rat compromised random flap model. METHODS: A rat random flap model was used with subjects divided into three groups: 1) control group; 2) QD HBO2; and 3) BID HBO2, where HBO2 was performed with 100% oxygen at 2.5 atmospheres absolute/ATA (253 kPa) for 90 minutes. After 10 days, areas of flap necrosis were measured and biopsies were taken for histologic analysis. Statistical analysis was performed using ANOVA and paired t-tests. A P-value ⟨0.05 was considered significant. RESULT: Both treatment groups had significantly increased mean flap survival compared to controls (P⟨0.05). There was no significant difference in flap survival between the QD and BID groups. Capillary proliferation in the QD group was increased compared with controls. CONCLUSION: Both QD and BID HBO2 protocols can significantly decrease random flap necrosis. However, the results of this study suggest there is no additional benefit gained with BID treatments. Clinical studies are warranted to confirm these findings and assist in formalization of protocols for the use of HBO2in treating compromised random flaps.

Effects of Traditional Chinese Medicine, Dilong Injection, on Random Skin Flap Survival in Rats.

BACKGROUND: Dilong injection as a medicinal preparation extracted from earthworm in traditional Chinese medicine, is used to activate blood circulation and remove blood stasis. In this research, we aim to investigate its potential effect on random skin flap survival in rat models. MATERIALS AND METHODS: McFarlane flaps were established in 60 male Sprague-Dawley rats randomly divided into two groups: the control group and the Dilong injection group. Diong injection group was injected with the Diong injection (4 mL/kg) once a day for seven days, and the control group was given an equal volume of saline solution. After seven days, flaps were obtained and stained with Hematoxylin and Eosin. Histological examination was done to determine changes in histology such as thickness of granulation tissue, tissue edema, neutrophil infiltration, and the microvascular density (MVD). In addition, immunohistochemical detection was carried out to show vascular endothelial growth factor (VEGF) expression level. RESULTS: Compared with the control group, the Dilong group exhibited more fibroblastic proliferation, thinner neutrophil infiltration with less edema through histological examination. The MVD and the VEGF expression of flaps were significantly higher. The mean superoxide dismutase activity was evidently higher in the Dilong group than in the control group, while the mean MDA level was lower. CONCLUSIONS: According to the comparison made between the two groups for histological and immunohistochemical evaluation, the Dilong injection group has potential effects on the survival of random skin flaps in rat models.

Naringin improves random skin flap survival in rats.

BACKGROUND: Random-pattern flap transfer is commonly used to treat soft-tissue defects. However, flap necrosis remains a serious problem. Naringin accelerates angiogenesis by activating the expression of vascular endothelial growth factor (VEGF). In the present study, we investigated whether naringin improves the survival of random skin flaps. RESULTS: Compared with controls, the naringin-treated groups exhibited significantly larger mean areas of flap survival, significantly increased SOD activity and VEGF expression, and significantly reduced MDA level. Hematoxylin and eosin (HE) staining revealed that naringin promoted angiogenesis and inhibited inflammation. MATERIALS AND METHODS: "McFarlane flap" models were established in 90 male Sprague-Dawley (SD) rats divided into three groups: a 40 mg/kg control group (0.5 % sodium carboxymethylcellulose), a 40 mg/kg naringin-treated group, and an 80 mg/kg naringin-treated group. The extent of necrosis was measured 7 days later, and tissue samples were subjected to histological analysis. Angiogenesis was evaluated via lead oxide-gelatin angiography, immunohistochemistry, and laser Doppler imaging. Inflammation was evaluated by measurement of serum TNF-α (tumor necrosis factor-α) and IL-6 (interleukin-6) levels. Oxidative stress was assessed by measuring superoxide dismutase (SOD) activity and the malondialdehyde (MDA) level. CONCLUSION: Naringin improved random skin flap survival.

Saphenous artery-based flap models in rats: new flap designs for experimental studies.

BACKGROUND: Experimental research using laboratory animals provides substantial data about reconstructive surgery. However, the literature does not include any experimental studies that have used flap models on the hind limbs of rats. To gain an understanding of the physiology of lower-extremity flaps and of flap failures, this study assessed the cutaneous perforators of the saphenous artery, and new flap models were designed for the hind limbs of rats. MATERIALS AND METHODS: The experiment was designed to include three stages and used 35 rats. The first stage involved mapping the perforators of the saphenous artery. In the second stage, the contents and structures of McFarlane, epigastric, and anterior hind limb flap tissues were compared histologically. The third stage of the study involved designing and comparing different flaps for the hind limbs of the rats and included random flaps, perforator-based peninsular flaps, perforator-based island flaps, and perforator-based flaps with rotated pedicles. Postoperative necrosis ratios were evaluated using computer-based software. RESULTS: Mapping of the saphenous artery perforators revealed an average of 2.2 septocutaneous arteries in each hind limb. Histologic studies showed thick dermis and panniculus carnosus in the McFarlane flaps, thick dermis, and thin panniculus carnosus layers in the epigastric flaps, and thin subcutaneous tissue with no panniculus carnosus tissue in the skin of the hind limbs. The results of the flap studies that used random flaps showed a 52.4% necrosis, while there was no necrosis when perforator-based peninsular flaps, island flaps, and flaps with rotated pedicles were used. CONCLUSIONS: New flap models used on the saphenous artery perforators of the hind limbs of rats can provide valuable information about the physiology of lower-extremity flaps. New studies can also be designed based on these flap models to acquire more knowledge about pathologic conditions such as ischemia and venous insufficiency.

Effects of diammonium glycyrrhizinate on random skin flap survival in rats: An experimental study.

Partial necrosis of skin flaps continues to restrict the survival of local skin flaps following plastic and reconstructive surgeries. The aim of the present study was to investigate the effects of diammonium glycyrrhizinate (DG), a salt of glycyrrhetinic acid that has been widely used in the therapy of chronic hepatitis and human immunodeficiency virus infection, on random skin flap survival in rats. McFarlane flaps were established in 60 male Sprague-Dawley rats randomly divided into three groups. Group I served as the control group and was injected with saline (10 mg/kg) once per day. Group II and group III were the experimental groups, and were injected with 10 mg/kg DG once and twice per day, respectively. On day 7, the survival area of the flap was measured. Tissue samples were stained with hematoxylin and eosin and immunohistochemically evaluated. Tissue edema, neutrophil density, superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels were evaluated. The mean survival areas of the flaps of group II were significantly larger when compared with those of group I (P<0.05), and the rats of group III exhibited significantly higher survival areas than group II (P<0.05). Histologic and immunohistochemical evaluation showed that microvessel development and the expression level of vascular endothelial growth factor were higher in the two experimental groups than in the control group. Furthermore, SOD activity was significantly increased (P<0.05), while the neutrophil density and MDA level were significantly reduced (P<0.05) in group II when compared with group I. Significant differences between group II and group III with regard to SOD activity and MDA level were also observed (P<0.05). Thus, DG may have a dose-dependent effect on promoting the survival of random skin flaps.

Flap preconditioning by pressure-controlled cupping in a rat model.

BACKGROUND: Flap survival is essential for the success of soft-tissue reconstruction. Accordingly, various surgical and medical methods aim to increase flap survival. Because flap survival is affected by the innate vascular supply, traditional preconditioning methods mainly target vasodilatation or vascular reorientation to increase blood flow to the tissue. External stress on the skin, such as an external volume expander or cupping, induces vascular remodeling, and these approaches have been used in the fat grafting field and in traditional Asian medicine. MATERIALS AND METHODS: In the present study, we used a rat random-pattern dorsal flap model to study the effectiveness of preconditioning with an externally applied device (cupping) at the flap site that directly applied negative pressure to the skin. The device, the pressure-controlled cupping, is connected to negative pressure vacuum device providing accurate pressure control from 0 mm Hg to -200 mm Hg. Flap surgery was performed after preconditioning under -25 mm Hg suction pressure for 30 min a day for 5 d, followed by 9 d of postoperative observation. Flap survival was assessed as the area of viable tissue and was compared between the preconditioned group and a control group. RESULTS: The preconditioned group showed absolute percentage increase of flap viability relative to the entire flap by 19.0± 7.6% (average 70.1% versus 51.0%). Tissue perfusion of entire flap, evaluated by laser Doppler imaging system, was improved with absolute percentage increase by 24.2± 10.4% (average 77.4% versus 53.1%). Histologic analysis of hematoxylin and eosin, CD31, and Masson-trichrome staining showed increased vascular density in the subdermal plexus and more organized collagen production with hypertrophy of the attached muscle. CONCLUSIONS: Our study suggests that flap preconditioning caused by controlled noninvasive suction induces vascular remodeling that increases tissue perfusion and improves flap survival in a rat model.

Beneficial effects of Xuebijing injection on random skin flap survival in rats.

BACKGROUND: Improving survival of random skin flaps has important implications of reconstruction, and various kinds of agents have been tested for this purpose. In this study, the effects of Xuebijing (XBJ) injection on random skin flap survival in rats were evaluated. MATERIALS AND METHODS: McFarlane flaps were established in 40 rats divided into two groups. XBJ was injected into the test group, and the same concentration of saline was injected into controls. Tissues were stained with hematoxylin and eosin stain and immunohistochemically evaluated, and the survival area of the flaps, superoxide dismutase, and malondialdehyde contents were examined. RESULTS: Compared with the control group, we found the mean survival area of the flaps in the test group was significantly larger, expression of vascular endothelial growth factor and superoxide dismutase activity increased markedly in the test group, malondialdehyde level in the test group was significantly lower, and the hematoxylin and eosin-stained slices showed that inflammation was clearly inhibited in the test group. CONCLUSIONS: In summary, XBJ improved survival of random skin flaps.

Periorbital Soft Tissue Defects Reconstructed by Random Flaps / 中国医科大学学报

Objective To summerize the experiences of using random flaps to reconstruct soft tissue defects of the periorbital region.Methods Periorbital soft tissue defects in 65 patients underwent reconstruction surgery by random flaps with pedicle 1.0～2.5 cm in width.The length of the flap ranged from 1.0 cm to 3.5 cm,with the rate of length to width less than 2.5:1.Detail plans on flap and incision design were made based on the aesthetic and functional problems.Results Phenomena of blister and purplish red in the edge or the distal area of the flaps were observed in 3 cases,and were disappeared after corresponding treatment.The other flaps survived and the wound healed primarily after operation.The color and the texture of the flaps matched well to the adjacent tissues with satisfied function and aesthetic Results .Conclusion Random flap is an ideal substitute to repair periorbital soft tissue defects.