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Objective: In ophthalmic surgery, different materials and fixation methods are employed for bone flap repositioning after lateral orbitotomy approach (LOA), yet there is no unified standard. This study aims to investigate the impact of different fixation strategies on orbital stability through Finite Element Analysis (FEA) simulations of the biomechanical environment for orbital rim fixation in LOA., Methods: A Finite Element Model (FEM) was established and validated to simulate the mechanical responses under various loads in conventional lateral orbitotomy approach (CLOA) and deep lateral orbital decompression (DLOD) using single titanium plate, double titanium plates, and double absorbable plates fixation methods. The simulations were then validated against clinical cases., Results: Under similar conditions, the maximum equivalent stress (MES) on titanium alloy fixations was greater than that on absorbable plate materials. Both under static and physiological conditions, all FEM groups ensured structural stability of the system, with material stresses remaining within safe ranges. Compared to CLOA, DLOD, which involves the removal of the lateral orbital wall, altered stress conduction, resulting in an increase of MES and maximum total deformation (MTD) by 1.96 and 2.62 times, respectively. Under a horizontal load of 50 N, the MES in FEM/DLOD exceeded the material's own strength, with an increase in MES and MTD by 3.18 and 6.64 times, respectively, compared to FEM/CLOA. Under a vertical force of 50 N, the MES sustained by each FEM was within safe limits. Bone flap rotation angles remained minimally varied across scenarios. During follow-up, the 12 patients validated in this study did not experience complications related to the internal fixation devices., Conclusion: Under static or physiological conditions, various fixation methods can effectively maintain stability at the orbitotomy site, and absorbable materials, with their smoother stress transmission properties, are more suited for application in CLOA. Among titanium plate fixations, single titanium plates can better withstand vertical stress, while double titanium plates are more capable of handling horizontal stress. Given the change in the orbital mechanical behavior due to DLOD, enhanced fixation strength should be considered for bone flap repositioning., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

In reconstructive and plastic surgery, random skin flaps are commonly utilized to treat skin abnormalities produced by a variety of factors. Flap delay procedure is commonly used to reduce flap necrosis. Due to the limitations of various conditions, the traditional surgical improvement can't effectively alleviate the skin flap necrosis. And leonurine (Leo) has antioxidant and anti-inflammatory effects. In this study, we researched the mechanism underlying the influences of varied Leo concentrations on the survival rate of random skin flaps. Our results showed that after Leo treatment, tissue edema and necrosis of the flap were significantly reduced, while angiogenesis and flap perfusion were significantly increased. Through immunohistochemistry and Western blot, we proved that Leo treatment can upregulate the level of angiogenesis, while Leo treatment significantly reduced the expression levels of oxidative stress, apoptosis and inflammation. As a result, it can significantly improve the overall viability of the random skin flaps through the increase of angiogenesis, restriction of inflammation, attenuation of oxidative stress, and reduction of apoptosis. And this protective function was inhibited by LY294002 (a broad-spectrum inhibitor of PI3K) and L-NAME (NG- nitro-L-arginine methyl ester, a non-selective NOS inhibitor). All in all, Leo is an effective drug that can activate the eNOS via the PI3K/Akt pathway. By encouraging angiogenesis, preventing inflammation, minimizing oxidative stress, and lowering apoptosis, Leo can raise the survival rate of random skin flaps. The recommended concentration of Leo in this study was 30 mg/kg., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

This research is aimed at exploring the influences of the Bax gene in the p38 mitogen-activated protein kinase (MAPK) pathway and its protective mechanism against ischemia-reperfusion injury (IRI) of skin flap. Forty male Sprague-Dawley (SD) rats were equally divided into the experimental group (Bax gene knockout rats) and control group. The dorsal flap model was prepared, and the survival rate of flap was observed after surgery. The rat flap tissue was cut and stained with hematoxylin-eosin (HE) and in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The distribution characteristics of p38MAPK and Bax were detected to evaluate the protective mechanism of Bax gene knockout on IRI of skin flap. After surgery, the survival rate of flaps in the experimental group (82.32%, 70.28%) was significantly higher than that in the control group (57.64%, 46.14%) ( P < 0.05). The results of HE staining showed that on the 1 st day after surgery, compared with those in the control group, the skin flaps of the rats in the experimental group were arranged more neatly. The results of TUNEL staining showed that compared with that of the control group, the tissue structure of the skin flap of the experimental group was normal and only a few apoptotic cells appeared. In addition, compared with that in the control group (7.14, 4.25, 3.48, 2.18/6.46, 7.12, 4.86, and 2.44), the expression of Bax and p38 MAPK in the experimental group (0.96, 0.81, 0.76, 0.55/1.63, 1.33, 1.01, and 0.56) significantly decreased ( P < 0.05). In short, after the Bax gene was knocked out, injury of the flap after ischemia-reperfusion was considerably improved, which may play a protective role on the IRI of the flap by affecting the p38MAPK pathway., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Yapeng Wang et al.)

Objective: The investigation and practice of physical therapy in flap surgery are still scare. The purpose of this study is to evaluate the impact of different microneedling interventions on survival of random pattern flaps in rats, attempting to determine the optimal microneedling protocols for improvement of flap survival., Methods: Eighty male Sprague-Dawley rats were randomly divided into four groups, with 20 in each group (group A, B, C, and D). A 3 cm × 9 cm rectangular random flap as the McFarlane flap was adopted in each group. In groups A and B, microneedling treatment was performed before and after surgery, respectively. While animals in group C were received both pre- and postoperative microneedling treatment. Group D was used as a control group, which was only exposed to surgery. Flap survival, flap blood flow, number of capillary formations, the expressions of CD31, CD34, HIF-1α, and vascular endothelial growth factor (VEGF) were detected in each group and compared., Results: On the 7th day postoperatively, significant improvements with microneedling treatment were found in flap survival rate (p = 0.007), blood flow (p = 0.024), the expression levels of CD34 (p = 0.005), and the VEGF (p < 0.01). Furthermore, the VEGF expression level was significantly higher in group B when compared with the other three groups (all p < 0.01). However, there was no significant difference in the number of new blood vessels and other immunohistochemical indicators among the four groups (all p > 0.05)., Conclusion: Microneedling treatment especially postoperative intervention can significantly improve the survival of random flaps in rats., Competing Interests: Declaration of Competing Interest None declared., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Mastectomy flap necrosis affects 7 to 40 percent of patients undergoing immediate breast reconstruction, with many cases resulting in infection and/or explantation. The Intra.Ox near-infrared spectrometer is a novel device that assesses tissue perfusion by measuring the interactions of light with oxygenated and deoxygenated hemoglobin. This handheld device facilitates serial flap perfusion assessment and may objectively identify at-risk tissues and guide evidence-based treatment algorithms. In this preliminary study, we hypothesized that the Intra.Ox spectrometer detects differences in tissue oxygenation that correlate to tissue necrosis., Methods: Dorsal, random-pattern flaps measuring 10 × 3 cm were raised in eight male Sprague-Dawley rats. Intraoperative tissue oxygen saturation was measured using Intra.Ox in 10 standardized locations. On postoperative day 7, the skin flaps were evaluated for full-thickness necrosis. Data were analyzed using the chi-square test and one-way analysis of variance. A receiver operating characteristic curve assessed the accuracy of intraoperative tissue oxygenation in predicting the risk of flap necrosis., Results: Tissue oxygen saturation exhibited a strong negative correlation to distance from the flap pedicle (r = -0.798). Oxygen saturation in tissue that developed necrosis averaged 32 percent, compared to 59 percent in tissues that did not (p < 0.001). The area under the receiver operating characteristic curve was 0.969. Post hoc oxygen saturation cutoffs with 100 percent specificity and sensitivity in predicting necrosis were identified at 46 percent and 54 percent, respectively., Conclusions: Intra.Ox detects significant differences in tissue oxygenation saturation that are associated with the risk for flap necrosis. This technology can be used to identify at-risk tissues and represents an avenue for research aimed at preventing flap necrosis., (Copyright © 2021 by the American Society of Plastic Surgeons.)

Free flap reconstruction is a common procedure with success rates greater than 99%. However, vascular complications may occur, resulting in flap failure. For this reason, early detection of vascular compromise is crucial for flap salvage. Vascular complications may be detected early by monitoring tissue oximetry parameter changes using near-infrared spectroscopy (NIRS). This method of noninvasive monitoring can evaluate changes in flap oxygenation levels caused by arterial and venous thrombosis before surgical reexploration. The goal of this study was to assess the validity of using NIRS oximetry for monitoring free flaps. We conducted a prospective cohort observational study of 10 patients undergoing breast reconstruction. We used the INVOS 7100 cerebral oximetry monitoring system (Medtronic, Dublin, Ireland) to provide 24-hr continuous postoperative monitoring of flap perfusion and compared the data with clinical assessment findings. The median patient age was 57 years (range = 41-61 years). Patients underwent immediate breast reconstruction with deep inferior epigastric perforator (DIEP) flap surgery (n = 4), delayed reconstruction with DIEP flap surgery (n = 4), transverse upper gracilis flap surgery (n = 1), and latissimus dorsi flap with lipofilling (n = 1). We successfully monitored all 10 flaps for 24 hr postoperatively. The overall flap survival rate was 100%. Findings of clinical examination, Doppler studies, and surgical outcome were consistent with NIRS monitoring. In conclusion, NIRS tissue oximetry could potentially provide a noninvasive method for effective postoperative monitoring of free flaps., Competing Interests: The authors declare that they have no conflict of interest., (Copyright © 2021 International Society of Plastic and Aesthetic Nurses. All rights reserved.)

Purpose: Near infrared spectroscopy (NIRS) measures tissue oximetry and perfusion of free tissue transfer with the advantage of remote wireless monitoring for free tissue transfer. It has been widely used in breast and extremity reconstruction but has had limited adoption in the head and neck., Materials and Methods: A retrospective review of head and neck microvascular reconstruction by three different surgical services over 15 months at one tertiary care hospital was performed. Demographics, flap type, monitoring technique, complications, and flap outcomes were recorded. Monitoring techniques were (1) implantable/handheld Doppler or (2) NIRS. Flap monitoring outcomes were evaluated using multivariate analysis., Results: 119 flaps were performed by four surgeons with a success rate of 92% (109/119). Flaps were monitored with Doppler (40%) or NIRS (60%). There was no difference in flap success based on monitoring technique. An ROC analysis identified that the optimal cutoff in immediate StO 2 for classifying flap success at discharge was 68%., Conclusions: NIRS was successfully implemented in a high-volume head and neck reconstructive practice. NIRS remote monitoring allowed for flap surveillance without requiring in-hospital presence and was able to identify both arterial and venous compromise., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Diabetes mellitus increases the susceptibility of free tissue transplantations to ischemia-reperfusion injury. The aim of this study was to enhance nitric oxide (NO) bioavailability through exogenous NO synthase and the substrate L-arginine to attenuate ischemia reperfusion-induced alterations in a type 2 diabetes rodent model., Material and Methods: Sixty-four Wistar rats were divided into 8 experimental groups. Type 2 diabetes was established over 3 months with a combination of a high-fat diet and streptozotocin. A vascular pedicle isolated rat skin flap model that underwent 3 h of ischemia was used. At 30 min before ischemia, normal saline, endothelial NOSs (eNOSs), inducible NOSs, neuronal NOSs (1 and 2 IU), and L-arginine (50 mg/kg body weight) were administered by intravenous infusion alone or in combination. Ischemia-reperfusion-induced alterations were measured 5 days after the operation., Results: The three isoforms of NOS significantly increased the flap vitality rate (VR) between 20% and 28% as compared to the control group (3%). Sole L-arginine administration increased the VR to 33%. The combination of L-arginine with NOS resulted in a further increase in flap VRs (39%-50%). Best results were achieved with the combination of eNOS and L-arginine (50%). An increase in enzyme dosage led to decreased VRs in all NOS isoforms alone and even in combination with L-arginine., Conclusion: Modulation of NO bioavailability through the exogenous application of NOSs and L-arginine significantly attenuated ischemia-reperfusion-induced alterations in a type 2 diabetic skin flap rat model. The combination of enzyme and substrate result in the highest VRs. Higher enzyme dosage seems to be less effective. This pharmacological preconditioning could be an easy and effective interventional strategy to support the conversion of L-arginine to NO in ischemic and in type 2 diabetic conditions., Competing Interests: Declaration of Competing Interest None declared., (Copyright © 2020. Published by Elsevier Ltd.)

Background and objective : No current nationwide consensus exists on pilonidal disease (PD) treatment in Switzerland and Austria. The objective of this study was to assess and compare the spectrum of PD treatment strategies in Switzerland and Austria. Materials and Methods : A survey including 196 certified institutions (Switzerland, N = 99 and Austria, N = 97) was performed. Treatment strategies for both chronic and acute pilonidal disease were investigated, as well as evolution of treatment over the last 20 years. Results : In total, 92 of 196 (47%) hospitals participated in the survey. Recurrence rate (20%) was similar between the two countries. In acute pilonidal disease, a two-stage approach with incision and drainage as the first step was preferred over a one-stage procedure in both countries. In Austria, all patients with chronic pilonidal disease were treated as inpatients, whereas 28% of patients in Switzerland were treated on an outpatient basis ( p = 0.0019). Median length of hospital stay was double in Austria (four days) compared to Switzerland (two days; p < 0.001). Primary resection and off-midline closure ( p = 0.017) and the use of tissue flaps ( p = 0.023) were performed more commonly in Austria than in Switzerland. Minimally invasive techniques were performed more often in Switzerland than in Austria (52% vs. 4%, p < 0.001). Overall, wide excision with secondary wound healing or midline closures declined over the last 20 years. Conclusion : Treatment strategies for chronic PD differ between Austria and Switzerland with more and longer inpatient care in Austria, increasingly minimally invasive approaches in Switzerland, and outdated procedures still being performed in both countries. Overall, heterogeneity of practice dominates in both countries.

Objective: To develop a novel approach for tissue engineering of soft-tissue flaps suitable for free microsurgical transfer, using an injectable nanofiber hydrogel composite (NHC) vascularized by an arteriovenous (AV) loop. Approach: A rat AV loop model was used for tissue engineering of vascularized soft-tissue flaps. NHC or collagen-elastin (CE) scaffolds were implanted into isolation chambers together with an AV loop and explanted after 15 days. Saphenous veins were implanted into the scaffolds as controls. Neoangiogenesis, ultrastructure, and protein expression of SYNJ2BP, EPHA2, and FOXC1 were analyzed by immunohistochemistry and compared between the groups. Rheological properties were compared between the two scaffolds and native human adipose tissue. Results: A functional neovascularization was evident in NHC flaps with its amount being comparable with CE flaps. Scanning electron microscopy revealed a strong mononuclear cell infiltration along the nanofibers in NHC flaps and a trend toward higher fiber alignment compared with CE flaps. SYNJ2BP and EPHA2 expression in endothelial cells (ECs) was lower in NHC flaps compared with CE flaps, whereas FOXC1 expression was increased in NHC flaps. Compared with the stiffer CE flaps, the NHC flaps showed similar rheological properties to native human adipose tissue. Innovation: This is the first study to demonstrate the feasibility of tissue engineering of soft-tissue flaps with similar rheological properties as human fat, suitable for microsurgical transfer using an injectable nanofiber hydrogel composite. Conclusions: The injectable NHC scaffold is suitable for tissue engineering of axially vascularized soft-tissue flaps with a solid neovascularization, strong cellular infiltration, and biomechanical properties similar to human fat. Our data indicate that SYNJ2BP, EPHA2, and FOXC1 are involved in AV loop-associated angiogenesis and that the scaffold material has an impact on protein expression in ECs., Competing Interests: S.K.R., J.M.S., and H.Q.M. are inventors on intellectual property covering the technology that has been filed by Johns Hopkins and have equity positions in LifeSprout, a privately held company that is seeking to bring these advances into clinical development. The content of this article was written by the authors listed. No ghostwriters were used to write this article., (Copyright 2020, Copyright © 2020 by Mary Ann Liebert, Inc., publishers.)

Background: Medical therapy for flap survival has been extensively investigated. In this study, we explored the effect of citicoline (CDP-choline, CDPC), used for clinical treatment of cerebral trauma, on random skin flap survival in rats., Materials and Methods: Sixty rats were divided into three groups: low-dose (CDPC-L), high-dose (CDPC-H), and control. The CDPC-L and CDPC-H groups were intraperitoneally injected with 100 mg/kg and 300 mg/kg CDPC every day, respectively; the control group was injected with an equivalent volume of normal saline. The survival region was assessed on the 7th day after the flap operation. The microvascular density and neutrophil density were measured by hematoxylin and eosin staining. Lead angiography was used to detect angiogenesis, and laser Doppler was used to detect blood perfusion. Expression levels of vascular endothelial growth factor (VEGF), interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, Toll-like receptor (TLR) 4, and nuclear factor kappa B (NF-κB) were detected by immunohistochemistry. Malondialdehyde and superoxide dismutase were used to determine the lipid peroxidation level., Results: The average survival region of the flap was significantly larger in the CDPC-H group than in CDPC-L and control groups, with less ischemic necrosis. VEGF expression, microvascular density, angiogenesis, blood perfusion, and superoxide dismutase in the flap were higher in the CDPC-H group than in the CDPC-L and control groups. In addition, levels of neutrophil density, IL-1β, IL-6, TNF-α, TLR4, NF-κB, and malondialdehyde decreased significantly in the CDPC-H group., Conclusion: High-dose CDPC injection after a random flap operation is beneficial for flap survival., Competing Interests: Declaration of Competing Interest The authors declared that there is no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The purpose of this study was to assess the correlation between tissue volume and blood flow of the flap in an animal model. Using animal model, tissue volume can be attenuated, and precise change of blood flow could be evaluated. We further investigate the relationship between blood flow and vascular density in the tissue. In this study, we assessed flap conductance (ml/min/mm Hg) as to evaluate the conductivity of blood flow into the flap. Japanese white rabbit was used (n = 7) for this study. The amount of blood flow of jejunal and latissimus dorsi muscle (LD) flaps was measured while removing the distal portion of the flap sequentially. Conductance at each time was calculated from blood pressure and blood flow volume. The tissue volume at each time was also measured. The correlation between conductance and volume was analyzed using a linear mixed model. Immunohistochemical evaluation of microvessel densities (MVD) in these tissues was also performed for CD31/PECAM1 positive area. Conductance and tissue volume were significantly correlated in both jejunal and LD flaps. As the volume increases by 1 cm 3 , the conductance increased significantly by 0.012 ml/min/mm Hg in jejunum, and by 0.0047 ml/min/mm Hg in LD. Mean MVD was 1.15 ± 0.52% in the jejunum and 0.37 ± 0.29% in the LD muscle. In this study, we revealed that flap conductance is proportional to volume and proportional constant is different between the type of tissue. It suggests that the difference of MVD creates the unique conductance of each tissue., Competing Interests: The authors have no conflicts of interest, whether they are financial or related to any other relationships, to disclose.

Treating soft tissue defects occurring over the posterior elbow is challenging., Purpose: This study aimed to evaluate the long-term outcomes of using rotation flaps for soft tissue defects over the posterior elbow., Methods: A retrospective study was conducted among patients who had sustained posterior elbow defects and underwent rotation flap under local anesthesia between January 2, 2011, and December 31, 2014. Patient inclusion criteria stipulated the soft tissue defect had to be small (<12 cm2), was the result of wound dehiscence following posterior approach surgery immediately following trauma, and had failed to heal using nonsurgical treatment or primary closure. Patients with an active infection, malignancies, a defect of any etiology other than trauma, or incomplete operative data were excluded. Patient demographics, medical history, operative reports, and outcomes were abstracted. Flap failure and surgical complications were monitored for a minimum of 2 years after surgery. Range of motion (ROM; 0˚ to normal 130˚) and Mayo Elbow Performance Scores (MEPS) were evaluated and recorded before surgery and after 2 years' follow-up and included evaluating pain, ROM, stability, and daily function. Patient, wound, surgical, and wound healing variables were compared between the flap survival and flap failure/complication groups using Mann-Whitney U and chi-squared tests. The Wilcoxon signed-rank test was used to compare pre- and postoperative MEPS and elbow ROM., Results: Thirty (30) patients (13 male, 17 female; mean age 55 ± 15.6 [range 19-74] years) had complete records. Eighteen (18) flaps were created using the transolecranon approach, and 12 rotation flaps involved an olecranon fracture; 24 flaps survived and 6 patients experienced flap failure/complications (wound dehiscence or infection). Mean procedure duration was 25.6 ± 10.1 minutes. All defects were located over the olecranon with exposed bone or hardware. Mean defect size was 7.4 cm2 ± 2.9 cm2, the average defect duration was 60.4 (range 31-89) days, average time to wound healing was 21.9 ± 11.5 days, and mean follow-up time was 29.4 (range 24-56) months. All flaps successfully survived without recurrence. Mean pre- and postoperative MEPS were significantly different (56.4 vs. 90.2 points; P <.001). ROM did not differ significantly between mean preoperative range (extension 9.8˚ ± 3.2˚ and flexion 116.7˚ ± 10.2˚) and mean final follow-up range (extension 9.6˚ ± 2.6˚ and flexion 118.5˚ ± 11.3˚; P = .459)., Conclusion: Rotation flap surgery performed under local anesthesia may offer a simple and safe option in the treatment of small (<12 cm2) trauma-related defects over the posterior elbow. More research is needed to develop evidence-based guidelines for optimal approaches to posterior elbow soft tissue defect closure techniques.

Background: D-allose was promising in the protection of ischemia/reperfusion (I/R) injury. We intended to investigate the function of D-allose in skin flap of rat followed by the injury of I/R and whether ERK signal pathway was involved in., Methods: The back flap of Wistar rats was picked up with a vascular bundle of the lateral chest wall. I/R model was made by the venous clamp for 6 h. Rats received D-allose and PD-98059, the inhibitor of ERK1/2, 30 min before modeling. Morphology of tissue was observed by HE staining. Nitric oxide (NO), myeloperoxidase (MPO), malondialdehyde (MDA) and superoxide dismutase (SOD) levels in skin flap were determined by ELISA kits. mRNA and protein levels were determined by qPCR and Western blot respectively., Results: D-allose alleviated the condition of pathological changes and raised the survival rate of skin flap injured by I/R. Moreover, D-allose suppressed NO, MPO and MDA while elevated SOD levels during I/R status. Furthermore, D-allose decreased MCP-1, TNF-α, IL-1β and IL-6 levels in skin flap injured by I/R. In addition, D-allose inhibited MKP-1 expression and activated ERK1/2 pathway in skin flap injured by I/R. PD-98059 partially counteracted D-allose effects on I/R injury., Conclusions: D-allose exerted its protective function via inhibiting MKP-1expression and further activated ERK1/2 pathway to suppress the progress of oxidative stress, inflammation and necrosis, contributing to the survival of skin flap injured by I/R. Thus, D-allose was promising in the transplantation of skin flap.

Platelet-rich fibrin (PRF) provides a scaffold for cell migration and growth factors for promoting wound healing and tissue regeneration. Here, we report using PRF in periodontal healing after open flap debridement (OFD) in canine periodontitis. A split-mouth design was performed in twenty dogs. Forty periodontitis surgical sites were randomly categorized into 2 groups; OFD alone and OFD with PRF treatment. Clinical parameters of periodontal pocket depth, gingival index, and the cemento-enamel junction-alveolar bone levels/root length ratio were improved in the OFD + PRF group. The OFD + PRF group also demonstrated a dramatically decreased inflammatory score compared with the OFD group. Collagen accumulation was improved in the OFD + PRF group at later time points compared with baseline. PRF application also significantly reduced inflammatory cytokine expression (TNFA and IL1B), and promoted the expression of collagen production-related genes (COL1A1, COL3A1, and TIMP1) and growth factors (PDGFB, TGFB1, and VEGFA). These findings suggest that PRF combined with OFD provides a new strategy to enhance the overall improvement of canine periodontitis treatment outcomes, especially in terms of inflammation and soft tissue healing. Therefore, PRF use in treating periodontitis could play an important role as a regenerative material to improve canine periodontitis treatment.

V-Y flap is widely used in plastic surgery as an important technique for reconstructing deformities and improving appearance. In this paper, a geometrical parameter model and finite element analysis were used to study the rationale of the proposed V-Y flap design and the preoperative evaluation of the V-Y flap design. First, a geometric parameter model of the V-Y flap was established to analyze the five key geometric relationships affecting the flap structure and obtain a reasonable plan for the V-Y flap design through the crossing constraint relationship. Second, in order to verify the effectiveness of the V-Y flap design, the suture and release states of the V-Y flap during surgery were evaluated based on a simulation model of the V-Y flap generated by finite element analysis software. The results revealed that the approach proposed in this paper provides a feasible method for clinical V-Y flap design., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2020 Zong-Lin Yang et al.)

The use of grafts and flaps serves as an integral tool in the armamentarium of the reconstructive surgeon. Proper planning and surgical judgment are critical in the ultimate success of these procedures. However, there are situations when grafts and/or flaps can become compromised and require urgent intervention for salvage. These instances can include irradiated or otherwise hypoxic wound beds, excessively large harvested grafts, random flap ischemia, venous or arterial insufficiency, and ischemia-reperfusion injury. Alternatively, compromised grafts and flaps can be inadvertently created secondary to trauma. It is in these types of cases, hyperbaric oxygen (HBO2) therapy can serve as a useful adjunct in the salvage of compromised flaps and grafts. This review outlines the extensive basic science and clinical evidence available in support of the use of HBO2 therapy for compromised grafts and flaps. The literature demonstrates the benefit of adjunctive HBO2 therapy for multiple types of grafts and flaps with various etiologies of compromise. HBO2 therapy can enhance graft and flap survival by several methods including decreasing the hypoxic insult, enhancing fibroblast function and collagen synthesis, stimulating angiogenesis and inhibiting ischemia-reperfusion injury. The expedient initiation of hyperbaric oxygen therapy as soon as flap or graft compromise is identified maximizes tissue viability and ultimately graft/flap salvage., Competing Interests: The author of this paper declares no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Background: Mature adipocytes dedifferentiate in vivo on application of a soft-tissue expander. Dedifferentiated adipocytes can proliferate and redifferentiate. This study used tissue expanders to pretreat adipose flaps, to increase the retention rate after fat graft., Methods: A soft-tissue expander and silicone sheet were implanted beneath the left and right inguinal fat pads of rats, respectively. After 7 days of expansion, the adipose tissue derived from the pads was transplanted beneath dorsal skin. Samples were harvested at various time points, and histologic, immunohistochemical, and gene expression analyses were conducted. Mature adipocytes were cultured in vitro under a pressure of 520 Pa. Changes in cell morphology, the cytoskeleton, and expression of mechanical signal-related proteins were investigated., Results: Pressure in adipose flaps increased to 25 kPa on expansion. Mature adipocytes dedifferentiated following expansion. At 1 week after transplantation, the expression of vascular endothelial growth factor (p < 0.05) was higher in the expanded group. The retention rate at 12 weeks after transplantation was higher in the expanded group (56 ± 3 percent) than in the control group (32 ± 3 percent) (p < 0.05), and the surviving/regenerating zones (p < 0.01) were wider. The lipid content of mature adipocytes gradually decreased on culture under increased pressure, and these cells regained a proliferative capacity. This was accompanied by increased expression of mechanical signal--related proteins (p < 0.05)., Conclusions: Mechanical signals may induce dedifferentiation of mature adipocytes. Dedifferentiated adipocytes increase the retention rate of fat grafts by acting as seed cells.

Background: Random flaps are commonly used to repair wounds and improve the clinical appearance. However, flap necrosis is frequently encountered in the clinical setting. Adiponectin is a biologically active endogenous polypeptide secreted by adipocytes that can reduce oxidative stress, inflammation, and apoptosis. This study was performed to explore the effects of adiponectin on the survival of random flaps in rats., Materials and Methods: Thirty-six healthy rats were divided into two groups, i.e., an adiponectin group and a control group. A modified McFarlane flap was created on the backs of the rats. The area of flap survival was gauged after sacrifice of the rats on day 7 after surgery, and the tissue samples were subjected to histological analysis. Angiogenesis was assessed by oxide-gelatin angiography, laser Doppler imaging, and immunohistochemistry. Pathological changes in the flaps were examined by hematoxylin and eosin staining. The level of oxidative stress was evaluated using malondialdehyde (MDA) and superoxide dismutase (SOD) kits., Results: The adiponectin group had a larger tissue survival area and less edema compared with the control group. VEGF expression and SOD activity were markedly increased, but the MDA level was significantly decreased, in the adiponectin group. Histological analysis showed that adiponectin promoted angiogenesis and inhibited inflammation., Conclusions: Adiponectin is useful for improving random skin flap survival., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: This study was to investigate the effects of recombinant human growth hormone (rhGh) on ischemia-reperfusion (I/R) injury of mouse flaps., Methods: Healthy mice were randomly divided into four groups as follows: sham group, the IR group, the sham+rhGH group and the IR+rhGH group, with 12 mice in each group. Skin pathology was tested by hematoxylin and eosin staining. The flap survival of each group was measured after 7 days. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were determined using corresponding kit. The levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in serum and flap were respectively measured by performing enzyme-linked immunosorbent assay and quantitative real-time (qRT)-PCR. The expressions of cleaved caspase-3, B cell lymphoma/leukemia-2 (Bcl-2), Bcl-2-associated X protein (Bax), vascular endothelial growth factor (VEGF), MnSOD, toll-like receptor 4 (TLR4), and galectin-3 and (p)-p65 were analyzed by RT-PCR or/and Western blot., Results: Prophylactic systemic application of recombinant human GH reduced the pathological damage of skin IR and significantly improved the flap survival of IR in mice, accompanied by elevation of VEGF. After administration of recombinant human GH, the activity of SOD/MnSOD in the flap was significantly increased, while the content of MDA was decreased. Cleaved caspase-3 and Bax were downregulated and Bcl-2 was upregulated in IR+rhGH group, compared to IR group. The levels of TLR4, Galectin-3 and p-p65 were decreased by rhGH., Conclusion: rhGH had protective effects on flap IR injury, and can be used as a drug intervention target for the treatment of skin flap IR injury., (© 2019 Wiley Periodicals, Inc.)

Random-pattern skin flaps are commonly used and valuable tools in reconstructive surgery, however, post-operative random skin flap necrosis remains a major and common complication. Previous studies have suggested that activating autophagy, a major pathway for degradation of intracellular waste, may improve flap survival. In this study, we investigated whether trehalose, a novel and potent autophagy activator, improves random skin flap viability. Our results demonstrated that trehalose significantly improves viability, augments blood flow, and decreases tissue edema. Furthermore, we found that trehalose leads to increased angiogenesis, decreased apoptosis, and reduced oxidative stress. Using immunohistochestry and western blot, we demonstrated that trehalose augments autophagy, and that inhibition of autophagy augmentation using 3MA significantly blunted the aforementioned benefits of trehalose therapy. Mechanistically, we showed that trehalose's autophagy augmentation is mediated by activation and nuclear translocation of TFEB, which may be due to inhibition of Akt and activation of the AMPK-SKP2-CARM1 signaling pathway. Altogether, our results established that trehalose is a potent agent capable for significantly increasing random-pattern skin flap survival by augmenting autophagy and subsequently promoting angiogenesis, reducing oxidative stress, and inhibiting cell death.

With the advantage of handy process, random pattern skin flaps are generally applied in limb reconstruction and wound repair. Apelin-13 is a discovered endogenous peptide, that has been shown to have potent multiple biological functions. Recently, thermosensitive gel-forming systems have gained increasing attention as wound dressings due to their advantages. In the present study, an apelin-13-loaded chitosan (CH)/β-sodium glycerophosphate (β-GP) hydrogel was developed for promoting random skin flap survival. Random skin flaps were created in 60 rats after which the animals were categorized to a control hydrogel group and an apelin-13 hydrogel group. The water content of the flap as well as the survival area were then measured 7 days post-surgery. Hematoxylin and eosin staining was used to evaluate the flap angiogenesis. Cell differentiation 34 (CD34) and vascular endothelial growth factor (VEGF) levels were detected by immunohistochemistry and Western blotting. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were assessed by enzyme linked immunosorbent assays (ELISAs). Oxidative stress was estimated via the activity of tissue malondialdehyde (MDA) and superoxide dismutase (SOD). Our results showed that CH/β-GP/apelin-13 hydrogel could not only reduce the tissue edema, but also improve the survival area of flap. CH/β-GP/apelin-13 hydrogel also upregulated levels of VEGF protein and increased mean vessel densities. Furthermore, CH/β-GP/apelin-13 hydrogel was shown to significantly inhibit the expression of TNF-α and IL-6, along with increasing the activity of SOD and suppressing the MDA content. Taken together, these results indicate that this CH/β-GP/apelin-13 hydrogel may be a potential therapeutic way for random pattern skin flap.

Background: The thumb accounts for 50% of the total hand function. This study reports the functional outcomes and complications of people with traumatic thumb amputations who underwent toe-to-thumb reconstruction., Methods: From January 2013 to January 2018, 29 patients with second-degree thumb defect underwent thumb reconstruction with distal phalangeal braided toenail flap. The footscan foot pressure gait analysis system was used to measure the index changes of the same foot before and after 1, 3 and 6 months. The contact area, peak pressure, impulse value, contact time of each gait phase, centre of gravity coordinate and foot balance were analysed statistically., Results: Twenty-nine cases of thumb reconstruction recovered well. After following up for 6-15 months, the appearance of the reconstructed thumb was close to normal, and the sensation was restored to S3 + . The two-point discrimination was 6-8 mm, and the function of the thumb was good. The function of the donor foot was well restored, and no skin ulceration, pain and claudication were noted during walking. Compared with that before the operation, the biomechanical indices of the donor foot were basically restored to normal 6 months after the operation. Only the stress and impulse values of the third metatarsal head were significantly increased, forming a stress concentration area centred on the third metatarsal head., Conclusions: This study confirmed that the toenail flap with distal phalangeal bone restored the second-degree thumb defect without destroying the main functional structure of the sole. The biomechanical indices of the donor foot were basically restored to normal 6 months after the operation. Only the stress concentration area centred on the third metatarsal head, and the pain on the forefoot was induced after the operation. Discomfort, callus formation, metatarsal fasciitis, etc., can lead to fatigue fracture of the third metatarsal bone in severe cases, which requires further follow-up and observation., Trial Registration: Clinicaltrials.gov , NCT03879941; registered on 10 March 2019, retrospectively.

Background: The bilobed transposition flap recruits the relatively thinner and laxer skin of the nasal dorsum and sidewall to reconstruct defects of the more sebaceous nasal tip and alae. There have been no studies performed to quantify how the material properties of skin alter the bilobed flap's performance during nasal reconstruction., Objective: To determine the effects of skin thickness and stiffness on bilobed flap mechanics to help guide flap design principles and optimize surgical outcomes., Materials and Methods: Two-dimensional artificial silicone skin models of varying thickness were created. The bilobed flap was incised, transposed, and secured in standard fashion. Digital image correlation was used to translate model deformation and displacement into local stress and mechanical strain forces within the bilobed flap pedicle., Results: Qualitatively, the center of rotation of the bilobed flap rotates superiorly up the flap pedicle as model skin thickness increased., Conclusion: Location of the bilobed flap's pivot point may be dependent on local tissue characteristics-oversizing of the primary lobe can be considered in stiff, immobile tissue such as highly sebaceous Zone II nasal skin.

Aims: To assess the bone dimensional changes after extraction and alveolar ridge preservation (ARP) using primary coverage (closed flap technique, CFT) or healing by secondary intention (open flap technique, OFT)., Materials and Methods: Ten patients (split mouth design) were planned for extraction and ARP. All sites received ARP with freeze-dried bone allograft (FDBA) and nonresorbable membrane after extraction. Clinical standardized measurements were used to assess the dimensional alterations of the alveolar ridge., Results: All patients completed the study, and a total of 20 sites were randomized to CFT or OFT group. Center height (mean difference of 8.1 mm, SD =1.9 CFT, and 7.5 mm, SD= 1.8 OFT) and buccal height (mean difference of 0.8 mm, SD =1.0 CFT, and 0.3 mm, SD= 1.1 OFT) were significantly different within the same group. However, there was no statistically significant difference between groups. In the OFT group, the keratinized tissue width was higher and the pain VAS scores at 24 hours were lower compared with the CFT ( p = 0.004 and p = 0.006, respectively)., Conclusions: Leaving the flap open did not have any effects on the dimensional changes of bone height or width. However, there was a wider band of keratinized tissue and less pain with the CFT compared with the OFT. The study protocol was registered at ClinicalTrials.gov, Identifier NCT03136913., Competing Interests: The authors declare that they have no conflicts of interest.

Background: The gold standard surgical treatment of nerve injury includes direct repair, nerve graft, and neurolysis. The underlying effects (either beneficial or detrimental) of angiogenesis during nerve regeneration by rotational muscle flap have not yet determined. We assess the neurological outcome and angiogenesis of nerve injury following a rotational muscle flap., Methods: We retrospectively analyzed the outcome of the patients with severe radial nerve injury by neurolysis and rotational muscle flap; we also mimicked the clinical situation by nerve crush followed by rotational muscle flap in animals to assess associated angiogenesis factor expression., Results: Twenty-three out of 25 (92%) cases of severe radial nerve injury underwent neurolysis assisted by muscle flap rotation and eventually reached their preinjury neurological outcome. In the animal study, both FITC-dextran and Dil infusion showed a remarkably increased vascular structure in the crushed nerve integrated by the muscle flap and abolished by Avastin injection. The rotational muscle flap significantly increased angiogenesis factor expression, and this was attenuated by Avastin injection. The increased angiogenesis factor expression paralleled the improvement seen in neurobehavioral and electrophysiological studies as well as the significant expression of nerve regeneration markers and the restoration of denervated muscle morphology., Conclusion: Based on the clinical and animal data analysis, we conclude that muscle flap rotation provides a platform for angiogenesis in the acceleration of nerve regeneration. It appears that the muscle flap rotation augmented the nerve regeneration process which may be beneficial for nerve repair in clinical application., Competing Interests: The authors have declared that no competing interests exist.

Purpose: To analyze the acute effect of flap cut in laser in situ keratomileusis (LASIK) eyes and cap cut in small incision lenticule extraction (SMILE) eyes on corneal biomechanical properties of patients undergoing surgery., Methods: This was a prospective, interventional, longitudinal case series. Forty-eight eyes of 24 patients underwent contralateral LASIK and SMILE. Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) measurements were performed preoperatively, intraoperatively, and 1 week and 1 month after surgery. In LASIK eyes, the flap was cut but not lifted before intraoperative measurements. In SMILE eyes, the cap and side cut incision were made before intraoperative measurement. Thirty biomechanical variables were analyzed, assuming multiple comparisons., Results: In LASIK and SMILE eyes, 36.7% and 13.3% of the total number of variables detected biomechanical weakening after flap and cap cuts (P = .02), respectively. Further, 13.3% and 40% of the total variables detected no biomechanical changes after flap and cap cut, respectively (P = .03). These acute biomechanical effects of flap and cap cuts did not influence 1-week and 1-month measurements (P > .05) because both LASIK and SMILE eyes showed similar biomechanical weakening., Conclusions: Flap and cap cuts induced biomechanical weakening in patient corneas. The flap caused more weakening than the cap intraoperatively. However, biomechanical differences between LASIK and SMILE eyes were similar after removal of tissue and ongoing wound healing. [J Refract Surg. 2019;35(5):324-332.]., (Copyright 2019, SLACK Incorporated.)

BACKGROUND Skin flap grafting is one of the most common tissue transplantations for wound repair and organ reconstruction. Thus, improving the survival rate of the transplanted skin flap is important. Platelet-rich plasma (PRP) is an autologous platelet concentrate obtained from whole blood. It has been widely used in repairing tissue defects. Considering that the PRP gel has similar biological characteristics, this study used PRP gel for skin flap transplantation. MATERIAL AND METHODS PRP gel from Sprague-Dawley (SD) rats was prepared and the growth factor concentration was determined. A rat skin flap model was established to evaluate the survival rate of skin flap. Morphologic evaluation was also done. RESULTS We found that the PRP gel increased the survival rate of the skin flap. In addition, it reduces the inflammation response in skin flap transplantation and has better effects in terms of generating new soft tissue. CONCLUSIONS The effectiveness PRP gel in skin flap transplantation is satisfactory. The possible mechanisms by which PRP gel promotes the survival of the skin flap includes platelets, growth factors, immune activity factor, and fibrin. PRP could be a new clinical method for promoting skin flap survival.

Objective: Biomechanical evaluation of a novel expandable cranial fixation plate was assessed in cadavers. The dynamic craniotomy procedure uses low-profile reversibly expandable plates that allow cranial decompression by providing for intracranial volume expansion without removal of the bone flap. The plates allow reversible outward movement of the bone flap upon an increase in intracranial pressure (ICP) and also retract the bone flap and prevent it from sinking inside the cranium once the ICP normalizes., Methods: A comparative evaluation of the extent of ICP control with an increase in intracranial volume between various bone flap fixation techniques was undertaken along with testing of the expandable plate compliance. Static compression tests of the plates were performed to assess bone flap fixation and prevention of sinking. Quasi-static shear tension testing of the plates was undertaken to test the tolerance of the plates for expansion. Fatigue shear tension evaluation of the plates was undertaken to assess tolerance for repetitive expansion and contraction., Results: The dynamic craniotomy provided superior control of ICP with an increase in intracranial volume compared to the hinged craniotomy and standard craniotomy techniques (p < 0.001). Static compression results revealed that the plates withstood bone flap sinkage with a mean peak load of 643.3 ± 26.1 N and a mean inward bone flap displacement of 1.92 ± 0.09 mm. Static shear tension results indicated that the plates could withstand a peak expansion of 71.6 mm. Dynamic shear tension testing of the plates with repetitive 15-mm outward expansion and retraction for a total of up to 500 cycles revealed no cracking and no failure points., Conclusions: The reversibly expandable plates provide for a low-profile bone flap fixation with rigid restriction of bone flap sinking and also enable cranial decompression with a high tolerance for repetitive expansion and contraction.

Background: Skin flap procedures are employed in plastic surgery, but failure can lead to necrosis of the flap. Studies have used bone marrow mesenchymal stem cells (BM-MSCs) to improve flap viability. BM-MSCs and acellular amniotic membrane (AAM) have been introduced as alternatives. The objective of this study was to evaluate the effect of BM-MSCs and AAM on mast cells of random skin flaps (RSF) in rats., Methods: RSFs (80 × 30 mm) were created on 40 rats that were randomly assigned to one of four groups, including (I) AAM, (II) BM-MSCs, (III) BM-MSCs/AAM, and (IV) saline (control). Transplantation was carried out during the procedure (zero day). Flap necrosis was observed on day 7, and skin samples were collected from the transition line of the flap to evaluate the total number and types of mast cells. The development and the total number of mast cells were related to the development of capillaries., Results: The results of one-way ANOVA indicated that there was no statistically significant difference between the mean numbers of mast cell types for different study groups. However, the difference between the total number of mast cells in the study groups was statistically significant (p = 0.001)., Conclusion: The present study suggests that the use of AAM/BM-MSCs can improve the total number of mast cells and accelerate the growth of capillaries at the transient site in RSFs in rats.

Flap creation weakens the cornea and is a risk factor for keratectasia after laser in situ keratomileusis (LASIK). We describe a new technique to halt the progression of keratectasia by mechanically reintegrating the flap into the residual stroma. Deep stromal vertical puncturing is performed in the 4.0 to 9.0 mm paracentral corneal zone at a depth of 350 to 420 μm. The puncturing is applied in circumferential rows using a 25-gauge needle or a diamond blade, with denser puncturing at the level of the cone. In 5 eyes with worsening post-LASIK keratectasia, improved uncorrected and corrected visual acuities, corneal flattening, and a hyperopic shift were observed. There was no progression of keratectasia on serial topographies. New collagen fibrogenesis was documented by optical coherence tomography. The technique seems to be promising to halt the progression of post-LASIK keratectasia. More clinical data and longer follow-up are needed for validation., (Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Background: Vascularized lymph node transfer is a promising surgical treatment for lymphedema. This study investigated the effect of ischemia on the lymphatic drainage efficiency of vascularized lymph node flaps and the critical ischemia time of lymph nodes., Methods: Twenty-four lymph nodes containing groin flaps in 12 Sprague-Dawley rats were dissected. Clamping of the vascular pedicle was performed for 0, 1, 3, 5, 6, or 7 hours; then, each was allowed to reperfuse by means of the vascular pedicle for 1 hour. Perfusion and ischemic changes were assessed using indocyanine green lymphography; laser Doppler flowmetry; and histologic studies with associated lymphatic vessel endothelial hyaluronan receptor-1, CD68, 4',6-diamidino-2-phenylindole, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, and glutathione assay stains., Results: The mean latency period of the groin lymph node flaps was 247 ± 67, 83 ± 15, 72 ± 42, 30 ± 18, and 245 ± 85 seconds in the 0-, 1-, 3-, 5-, and 6-hour groups, respectively. Perfusion detected by laser Doppler was 85.2 ± 14.5, 87.2 ± 36.7, 129.8 ± 33.7, 140.4 ± 148.5, 156.1 ± 91.4, and 41.2 ± 34.8 perfusion units at ischemia times of 0, 1, 3, 5, 6, and 7 hours, respectively. Cell damage measured by glutathione was 46.8 ± 10.2, 67.7 ± 14.2, 62.8 ± 15.4, 126.6 ± 5.9, 259.0 ± 70.3, and 109.1 ± 27.5 at ischemia times of 0, 1, 3, 5, 6, and 7 hours, respectively. Histologically, as ischemia time increased, hemorrhage and congestion became more severe., Conclusions: The critical ischemia time of vascularized lymph nodes is 5 hours in the rodent animal model, verified by indocyanine green lymphatic fluid uptake, laser Doppler perfusion, and histologic assessments. Interestingly, lymphatic drainage and perfusion of vascularized lymph nodes were improved with an increased ischemia time before the critical 5 hours was reached.

Selective estrogen receptor modulators (SERMs) have been developed to achieve beneficial effects of estrogens while minimizing their side effects. In this context, we decided to evaluate the protective effect of genistein, a natural SERM, on skin flap viability in rats and in a series of in vitro experiments on endothelial cells (migration, proliferation, antioxidant properties, and gene expression profiling following genistein treatment). Our results showed that administration of genistein increased skin flap viability, but importantly, the difference is only significant when treatment is started 3 days prior the flap surgery. Based on our in vitro experiments, it may be hypothesized that the underlying mechanism may rather by mediated by increasing SOD activity and Bcl-2 expression. The gene expression profiling further revealed 9 up-regulated genes (angiogenesis/inflammation promoting: CTGF, CXCL5, IL-6, ITGB3, MMP-14, and VEGF-A; angiogenesis inhibiting: COL18A1, TIMP-2, and TIMP-3). In conclusion, we observed a protective effect of genistein on skin flap viability which could be potentially applied in plastic surgery to women undergoing a reconstructive and/or plastic intervention. Nevertheless, further research is needed to explain the exact underlying mechanism and to find the optimal treatment protocol., Competing Interests: The authors declare no conflict of interest.

Background: Thioredoxin-1 plays an important role in protecting the skin flap from ischemia-reperfusion injury. Ganoderma lucidum polysaccharide peptide is the major component of G. lucidum, which possesses potent antioxidant and antiapoptotic activity. This study aims to determine whether G. lucidum polysaccharide peptide could attenuate skin flap ischemia-reperfusion injury and to investigate possible mechanisms involved., Methods: G. lucidum polysaccharide peptide was administered to mice and epidermal cells before ischemia-reperfusion and hypoxia/reoxygenation, respectively. The thioredoxin-1 inhibitor PX-12 was introduced in the counterevidence group. The flap tissues and cells were tested by hematoxylin and eosin and immunohistochemistry staining, terminal deoxynucleotidyl transferase-mediated dUDP end-labeling assay, superoxide dismutase and malonic dialdehyde measurement, and Western blot., Results: The survival rates of ischemia-reperfusion flaps and hypoxia/reoxygenation cells increased significantly following G. lucidum polysaccharide peptide treatment. Mitigated tissue damage, reduced apoptosis, and enhanced antioxidant activity were observed in ischemia-reperfusion flaps replenishing G. lucidum polysaccharide peptide. Western blot analysis revealed thioredoxin-1 depletion and a remarkable increase in ASK-1, phospho-p38, cleaved caspase-3, and cleaved PARP abundance in ischemia-reperfusion flaps and hypoxia/reoxygenation cells, whereas G. lucidum polysaccharide peptide dramatically up-regulated thioredoxin-1 and reduced the apoptosis-related protein expression. However, the rescue effect of G. lucidum polysaccharide peptide was notably blunted by supplementation with PX-12., Conclusions: The current investigation highlights the protective role of G. lucidum polysaccharide peptide in skin flap ischemia-reperfusion injury through a thioredoxin-1-dependent antioxidant and antiapoptotic pathway. This initial foray demonstrates the therapeutic value of G. lucidum polysaccharide peptide against ischemia-reperfusion and facilitates the understanding of its dermoprotective mechanism.

Near infrared spectroscopy (NIRS) is a technique whereby light is transmitted to the skin or the surface of a wound. Light is selectively absorbed or reflected in order to calculate the percentage of oxygenated and deoxygenated hemoglobin. By calculating this ratio, the level of tissue oxygen perfusion can be assessed. This article describes an NIRS imaging device and demonstrates its use as a clinical tool to predict future viability of skin flaps, potential for wound healing, and progress of closure following application of a biologic wound product. Several cases are examined., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Tissue expansion-related severe complication exists, and the poor blood supply is one of the causes. After decades of negative correlation between capsule pressure and blood flow was verified, the widely recognized expansion capsule pressure is still absent. A prospective randomized controlled trial was performed to explore the optimal expanding capsule pressure. Thirty subjects were randomly divided into 5 groups, received a weekly expanding on 60-, 70-, 80-, 90-, and 100-mm Hg capsule pressure, respectively. All patients achieved 8-week follow-up; hemodynamic assessment by SPY-indocyanine green (ICG) angiography was taken every 2 weeks. Standardized indexes from SPY-ICG angiography were used to assess the blood supply, in which the ratio of ingress rate and the ingress rate of normal skin (IR/NIR) reflects the arterial perfusion level, and the ratio of Engress Rate and IR (ER/IR) indicates the venous reflux level. The expansion-related adverse events during the trial were recorded. The IR/NIR and the ER/IR are both obviously negatively correlated to the capsule pressure of tissue expander (P ≤ 0.05, the ER/IR's correlation coefficient = -0.453; the IR/NIR's correlation coefficient = -0.482). The post-expansion IR/NIR increased significantly after 8 weeks of expansion (P ≤ 0.05) in 90-mm Hg group. And the post-expansion ER/IR was significantly elevated (P ≤ 0.05) in 80 and 90-mmHg groups. There were 2 expansion-related complications reported in 100-mm Hg group, whereas no complication occurred in 4 other lower groups. SPY-ICG angiography is an objective measurement for tissue expansion hemodynamic monitoring. The expanding capsule pressure of 80 to 90 mm Hg is a reasonable upper limit.

Objective: To investigate the effect of natural hirudin combined with hyperbaric oxygen therapy on the survival of transplanted random-pattern skin flap in rats., Methods: A random-pattern skin flap in size of 10.0 cm×2.5 cm was elevated on the dorsum of 72 Sprague Dawley rats. Then the 72 rats were randomly divided into 4 groups ( n =18) according to the therapy method. At immediate and within 4 days after operation, the rats were treated with normal saline injection in control group, normal saline injection combined with hyperbaric oxygen treatment in hyperbaric oxygen group, the natural hirudin injection in natural hirudin group, and the natural hirudin injection combined with hyperbaric oxygen treatment in combined group. The flap survival was observed after operation, and survival rate was evaluated at 6 days after operation. The skin samples were collected for histological analysis, microvessel density (MVD) measurement, and evaluation of tumor necrosis factor α (TNF-α) expression level by the immunohistochemical staining at 2 and 4 days after operation., Results: Partial necrosis occurred in each group after operation, and the flap in combined group had the best survival. The survival rate of flap was significantly higher in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group, and in combined group than in hyperbaric oxygen group and natural hirudin group ( P <0.05). There was no significant difference between hyperbaric oxygen group and natural hirudin group ( P >0.05). At 2 days, more microvascular structure was observed in hyperbaric oxygen group, natural hirudin group, and combined group in comparison with control group; while plenty of inflammatory cells infiltration in all groups. At 4 days, the hyperbaric oxygen group, natural hirudin group, and the combined group still showed more angiogenesis. Meanwhile, there was still infiltration of inflammatory cells in control group, inflammatory cells in the other groups were significantly reduced when compared with at 2 days. At 2 days, the MVD was significantly higher in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group ( P <0.05); the expression of TNF-α was significantly lower in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group ( P <0.05). There was no significant difference in above indexes between hyperbaric oxygen group, natural hirudin group, and combined group ( P >0.05). At 4 days, the MVD was significantly higher in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group, in natural hirudin group and combined group than in hyperbaric oxygen group ( P <0.05). The expression of TNF-α was significantly lower in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group, in combined group than in natural hirudin group and hyperbaric oxygen group ( P <0.05)., Conclusion: Hyperbaric oxygen and natural hirudin therapy after random-pattern skin flap transplantation can improve the survival of flaps. Moreover, combined therapy is seen to exhibit significant synergistic effect. This effect maybe related to promotion of angiogenesis and the reduction of inflammation response.

Background: Sensory restoration of the oral cavity is a primary aim of reconstructive surgery in posttraumatic or postablative defects. Sensitivity plays a key role in oral function, whose impairment strongly affects the patient's quality of life. Cheek myomucosal flaps provide a reliable and tissue-like reconstruction of these regions but their sensitive recovery, which we still know little about, deserves thorough assessment., Methods: In this retrospective study, the myomucosal cheek flaps were tested for different aspects of sensory recovery: touch; 2-point discrimination; pain; sharp/smooth discrimination; ability to feel hot/cold stimulus; stereognosis; and taste., Results: Fifty-two myomucosal flap reconstructions were investigated. All sensitivity tests showed positive results. When comparison was possible, sensitivity seemed significantly close to the contralateral healthy side. Sensory recovery proved to be even better than that reported on reinnervated microvascular free flap reconstructions of the oral cavity., Conclusion: Myomucosal flap reconstruction demonstrated a high degree of sensory recovery., (© 2017 Wiley Periodicals, Inc.)

Objective: To explore the effects of recombinant human growth hormone (rHGH) on the survival of the mouse slender narrow pedicle flap and the expressions of vascular endothelial growth factor (VEGF) and classification determinant 34 (CD34)., Materials and Methods: A total of 20 BALB/c mice were randomly divided into the experimental group (n=10) and control group (n=10). The flaps were transplanted for mice in two groups respectively. 6 h after the operation, the mice in the experimental group were administrated with rHGH via local subcutaneous injection, while the mice in the control group were injected with the same amount of normal saline. The laser Doppler was used to measure the sub-flap blood flow rates before the operation, and 3 days, 7 days and 14 days after the operation, respectively; the flap necrosis and survival areas of mice in two groups were measured respectively, and the survival rate of the flap was calculated 14 days after the operation. Afterwards, the flaps of mice in two groups were exfoliated and the shape and structure of flap tissues were tested by the hematoxylin-eosin (HE) staining. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to test the levels of mRNA and protein of VEGF and CD34 in the flap tissues., Results: The flaps of mice in the control group mainly exhibited the black or grayish-black and lost the elasticity with the hard texture, while those in the experimental group were ruddy in color with favorable elasticity. The survival rate of flaps of mice in the experimental group was significantly higher than that in the control group (83.61 ± 12.56% vs. 46.25 ± 9.70%) and the necrosis area of flaps of mice in the experimental group was significantly smaller than that in the control group (1.32 ± 0.16 vs. 4.13 ± 0.35, p < 0.05). There were no statistical differences in the blood flow rates of mouse flap both before the operation and three days after the operation between two groups (p > 0.05), while the blood flow rates of mouse flap both 7 days and 3 days after the operation in the experimental group were higher than those in the control group (p > 0.05). Compared with those in the control group, the levels of VEGF and CD34 were significantly increased, but the levels of the inflammatory factors of the interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were significantly decreased (p < 0.05)., Conclusions: rHGH plays an active role in the survival of the flap through promoting the angiogenesis and inhibiting inflammatory reaction.

Background: Frontofacial monobloc advancement creates a communication between the anterior cranial fossa and nasal cavities. To tackle this issue, transorbital pericranial pedicled flaps are routinely performed in the authors' center. This study aimed to assess the postoperative ossification of the anterior skull base and pedicled flaps following frontofacial monobloc advancement, and to identify factors influencing this ossification., Methods: Measurements of the skull base only and of the ossified pedicled flaps together with the skull base were performed on computed tomographic scans at the nasofrontal and the nasoethmoid frontal junctions. The total thickness of the skull vault was measured and a qualitative defect score for the anterior skull base was computed., Results: Twenty-two patients who underwent frontofacial monobloc advancement at a median age of 3.1 years (range, 1.9 to 3.6 years) were included: 14 with Crouzon, five with Pfeiffer, and three with Apert syndrome. One year and 5 years after surgery, the distraction gap was completely ossified in the anterior skull base midline in all patients. Ossified pedicled flaps together with the skull base were thicker in patients than in controls at these two time points (p < 0.005 and p < 0.02). Patients with Pfeiffer syndrome had a significantly thicker skull base only and ossified pedicled flaps together with the skull base thicknesses (p = 0.01 and p = 0.03) and lower defect scores than patients with Crouzon or Apert syndrome (p = 0.03) 1 year postoperatively., Conclusion: As ossification of the pedicled flaps and total reossification of the anterior skull base midline were observed in all patients, the authors indicate that performing pedicled flaps in frontofacial monobloc advancement surgery could promote the reossification of the anterior skull base., Clinical Question/level of Evidence: Therapeutic, IV.

Paramedian forehead flap is a workhorse for nasal reconstruction. However, vascular complications may lead to flap failure. The purpose of this study was to evaluate the blood flow objectively and determine the hemodynamic changes in paramedian forehead flap with respect to influential factors of age, gender, and smoking. Thirty patients who had paramedian forehead flap were followed up prospectively between 2010 and 2013. The blood flow was assessed by resistance index using Color Duplex-Doppler Ultrasonography. Resistance index was measured at the proximal and distal ends of each flap on the postoperative first day, first week, and second week. All data were analyzed using SPSS 15.0 for Windows. Fifteen patients were female and the mean of age was 60.9 years. Our results demonstrated statistically significant differences with gradual decreases in resistance to blood flow, when the resistance index values at the proximal and distal ends of paramedian forehead flap were compared (P < 0.001 and P < 0.001). Age, gender, and smoking did not have a negative impact on the resistance index values of paramedian forehead flap. To the best of our knowledge, this is the first study in which resistance in blood flow and hemodynamic changes of paramedian forehead flap were objectively determined using Color Duplex-Doppler Ultrasonography. The resistance index gradually decreases, although it is considerably high at the early postoperative interval. Age, gender, and smoking do not adversely influence the blood flow in a well-designed paramedian forehead flap.

Background: Random skin flaps are commonly used for wound repair and reconstruction. Electroacupuncture at The Zusanli point could enhance microcirculation and blood perfusion in random skin flaps., Objective: To determine whether electroacupuncture at The Zusanli point can improve the survival of random skin flaps in a rat model., Materials and Methods: Thirty-six male Sprague Dawley rats were randomly divided into 3 groups: control group (no electroacupuncture), Group A (electroacupuncture at a nonacupoint near The Zusanli point), and Group B (electroacupuncture at The Zusanli point). McFarlane flaps were established. On postoperative Day 2, malondialdehyde (MDA) and superoxide dismutase were detected. The flap survival rate was evaluated, inflammation was examined in hematoxylin and eosin-stained slices, and the expression of vascular endothelial growth factor (VEGF) was measured immunohistochemically on Day 7., Results: The mean survival area of the flaps in Group B was significantly larger than that in the control group and Group A. Superoxide dismutase activity and VEGF expression level were significantly higher in Group B than those in the control group and Group A, whereas MDA and inflammation levels in Group B were significantly lower than those in the other 2 groups., Conclusion: Electroacupuncture at The Zusanli point can effectively improve the random flap survival.

Background: In recent years, many studies have demonstrated that endogenous adenosine induced by ischemia postconditioning reduces apoptosis in various models, but no study has clearly elucidated the effects of hypoxic postconditioning (HPC) in human dermal microvascular endothelial cells (HDMECs) of flaps, and the subtype of adenosine receptors involved remains unknown. In our study, we sought to identify the role of adenosine A 2a receptor in the antiapoptotic effects of HPC., Materials and Methods: The HDMECs were isolated from human upper eyelid tissue. After hypoxia for 6 h, the HDMECs were either abruptly reperfused with medium for 12 h (reoxygenation) or postconditioned by three cycles of 5 min of transitory reoxygenation and 5 min of rehypoxia followed by 11.5 h of reoxygenation. CGS-21680 was used as an adenosine A 2a agonist., Results: Adenosine A 2a receptors were found in the cytoplasm of HDMECs. Hypoxia/reoxygenation (H/R) resulted in severe injury in HDMECs as evidenced by an increase in apoptosis percentage and an increase in expressions of apoptosis-related proteins (the ratio of Bax/Bcl-2 and caspase-3), which can be significantly attenuated by HPC treatment or exposure to CGS-21680, a selective adenosine A 2a receptor agonist (all P values < 0.05). Meanwhile, HPC treatment or CGS-21680 significantly activated A 2a receptors compared with the hypoxia/reoxygenation group (P < 0.05 versus P < 0.05, respectively). Statistical analysis showed that the increase of cell apoptosis closely correlated inversely with the increase of relative protein level of adenosine A 2a receptors (r 2  = 0.8177, P < 0.0001)., Conclusions: HPC protects against apoptosis induced by reoxygenation via activation of adenosine A 2a receptors on HDMECs., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Facial skin defects created by Mohs micrographic surgery are commonly reconstructed using local cutaneous flaps from surrounding skin. To provide optimal survival and aesthetic outcomes, the cutaneous surgeon must command a thorough understanding of the complex vascular anatomy and physiology of the skin as well as the imperative physiologic and biomechanical considerations when elevating and transferring tissue via local skin flaps., (Copyright © 2017 Elsevier Inc. All rights reserved.)