The eNOS-induced leonurine's new role in improving the survival of random skin flap.

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.

Exploration of the Protective Mechanism of Bax Removal against Ischemia Reperfusion Injury of Skin Flap through the p38 Mitogen-Activated Protein Kinase Pathway.

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 1st 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.

Monitoring Breast Reconstruction Flaps Using Near-Infrared Spectroscopy Tissue Oximetry.

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.

The effect of different modes of microneedling technique on random flap survival in rats.

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.

The Intra.Ox Near-Infrared Spectrometer Measures Variations in Flap Oxygenation That Correlate to Flap Necrosis in a Preclinical Rodent Model.

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.

Modulation of Nitric Oxide Bioavailability Attenuates Ischemia-Reperfusion Injury in Type II Diabetes.

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.

Remote monitoring of head and neck free flaps using near infrared spectroscopic tissue oximetry.

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 StO2 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.

Treatment Strategies for Pilonidal Sinus Disease in Switzerland and Austria.

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.

Preoperative Evaluation of V-Y Flap Design Based on Computer-Aided Analysis.

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.

Myelomeningocele Repair Combining a Double Cryopreserved Amniotic Membrane Homograft and the Keystone Flap in a 3-Year-Old Child: A Case Report.

INTRODUCTION: Early repair in patients affected by myelomeningocele (MMC) is of paramount importance in order to prevent infection, minimize neural tissue damage, and reduce mortality. Treatment must include duraplasty and possibly an adequate soft tissue coverage. Delayed surgery in MMC patients can be more tedious due to the less clear borders between the placode and the skin. Moreover, the risks of wound infection and breakdown increase significantly. CASE PRESENTATION: We present the unusual case of a large MMC in a 3-year-old patient treated by combining the recently described cryopreserved amniotic membrane (AM) as homograft for dural reconstruction and a bilateral Keystone flap for soft tissue reconstruction. DISCUSSION: Thanks to its anti-inflammatory and elastic proprieties, the AM can play an important role in preventing adhesion between the reconstructed layers, thus reducing the risk of spinal cord tethering. The Keystone flap, at the same time, allows the wound tension to be distributed widely over the flap margins and not only along the midline, which overlies the duraplasty, enhancing the scar quality and lowering the risk of cerebrospinal fluid recurrence and wound dehiscence, with no donor site morbidity.

Closure of Persistent, Small, Posterior Elbow Soft Tissue Defects Using a Rotation Flap: A Retrospective Study.

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.

Protective effect of citicoline on random flap survival in a rat mode.

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)-1ß, 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-1ß, 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.

Mechanical Signals Induce Dedifferentiation of Mature Adipocytes and Increase the Retention Rate of Fat Grafts.

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.

Trehalose promotes the survival of random-pattern skin flaps by TFEB mediated autophagy enhancement.

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.

Repair of thumb defect by using the toenail flap: biomechanical analysis of donor foot-a retrospective cohort study.

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.

An injectable thermosensitive hydrogel for sustained release of apelin-13 to enhance flap survival in rat random skin flap.

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)/ß-sodium glycerophosphate (ß-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/ß-GP/apelin-13 hydrogel could not only reduce the tissue edema, but also improve the survival area of flap. CH/ß-GP/apelin-13 hydrogel also upregulated levels of VEGF protein and increased mean vessel densities. Furthermore, CH/ß-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/ß-GP/apelin-13 hydrogel may be a potential therapeutic way for random pattern skin flap.

Effects of adiponectin on random pattern skin flap survival in rats.

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.

Increased angiogenesis by the rotational muscle flap is crucial for nerve regeneration.

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.