Comparison of perioperative complications of pedicled island flap in reconstruction of extremities.

PURPOSE: The aim of this study was to analyze the differences in perioperative complications for pedicled island flaps in the reconstruction of extremities and to identify the factors contributing to pedicled island flap necrosis. Furthermore, the flap indications based on these outcomes are summarized. METHODS: Based on the inclusion criteria, 228 skin flaps were included in this study. Univariate and multivariate analyses were used to identify the risk factors for pedicled island flap necrosis. Differences in perioperative complications between upper and lower extremities were analyzed using the chi-square test or Fisher's exact test. RESULTS: The average age of the patients was 38 years. The overall complication rate was 21.93%, including partial flap necrosis (10.09%) and total flap necrosis (5.70%). The overall complication rate and flap necrosis rate in upper extremity reconstruction were significantly lower than the rates in lower extremity reconstruction. Flap area and postoperative wound infection were statistically significant risk factors for pedicled island flap necrosis in extremity reconstruction. Preoperative contamination of the wound bed was a statistically significant risk factor for postoperative wound infection. CONCLUSIONS: The flap area and postoperative wound infection were both independent risk factors for pedicled island flap necrosis in extremity reconstruction. The causes contributing to the differences in perioperative complications between upper and lower extremities reconstruction included preoperative contamination of the wound bed, postoperative wound infection, and the flap area but were also related to anatomical factors of the skin flap. Pedicled island flaps are more suitable for small- and medium-sized soft tissue defects.

Clinical Application and the Free Posterior Thigh Perforator Flap.

OBJECTIVE: The posterior thigh region has been neglected as a donor site for free perforator flaps, likely due to difficulties in positioning the patient during surgery. This study describes the clinical application of the posterior thigh perforator flap based on the third perforating artery of the profunda femoris artery (PFA). METHODS: The free posterior thigh perforator flap based on the third perforating artery of the PFA was used for reconstruction of soft tissue defects in nine patients between February 2010 and May 2014. RESULTS: Flap sizes ranged from 12 × 7 cm to 20 × 13 cm. The length of the vascular pedicle averaged 10.28 cm, and the mean diameters of the third perforating artery and venae comitantes were 1.68 and 1.14 mm, respectively. All of the perforators originated from the PFA. Of the 9 free flaps used in 9 patients, 7 flaps survived completely. There were no early complications in these flaps. During the follow-up period, no patient experienced cold intolerance, scar contracture, or scar pain. There were no functional impairments at the donor or recipient sites. CONCLUSIONS: The posterior thigh flap based on the third perforating artery of the PFA is an excellent option for reconstructing soft tissue defects. The anatomical location of the third perforating artery is relatively consistent. The vascular pedicle is relatively longer and has large caliber vessels. The scar at the donor site can be well concealed with low morbidity. The skin color and texture of this flap show satisfactory results.

Multiple social platforms reveal actionable signals for software vulnerability awareness: A study of GitHub, Twitter and Reddit.

The awareness about software vulnerabilities is crucial to ensure effective cybersecurity practices, the development of high-quality software, and, ultimately, national security. This awareness can be better understood by studying the spread, structure and evolution of software vulnerability discussions across online communities. This work is the first to evaluate and contrast how discussions about software vulnerabilities spread on three social platforms-Twitter, GitHub, and Reddit. Moreover, we measure how user-level e.g., bot or not, and content-level characteristics e.g., vulnerability severity, post subjectivity, targeted operating systems as well as social network topology influence the rate of vulnerability discussion spread. To lay the groundwork, we present a novel fundamental framework for measuring information spread in multiple social platforms that identifies spread mechanisms and observables, units of information, and groups of measurements. We then contrast topologies for three social networks and analyze the effect of the network structure on the way discussions about vulnerabilities spread. We measure the scale and speed of the discussion spread to understand how far and how wide they go, how many users participate, and the duration of their spread. To demonstrate the awareness of more impactful vulnerabilities, a subset of our analysis focuses on vulnerabilities targeted during recent major cyber-attacks and those exploited by advanced persistent threat groups. One of our major findings is that most discussions start on GitHub not only before Twitter and Reddit, but even before a vulnerability is officially published. The severity of a vulnerability contributes to how much it spreads, especially on Twitter. Highly severe vulnerabilities have significantly deeper, broader and more viral discussion threads. When analyzing vulnerabilities in software products we found that different flavors of Linux received the highest discussion volume. We also observe that Twitter discussions started by humans have larger size, breadth, depth, adoption rate, lifetime, and structural virality compared to those started by bots. On Reddit, discussion threads of positive posts are larger, wider, and deeper than negative or neutral posts. We also found that all three networks have high modularity that encourages spread. However, the spread on GitHub is different from other networks, because GitHub is more dense, has stronger community structure and assortativity that enhances information diffusion. We anticipate the results of our analysis to not only increase the understanding of software vulnerability awareness but also inform the existing and new analytical frameworks for simulating information spread e.g., disinformation across multiple social environments online.

Red fluorescent AuNDs with conjugation of cholera toxin subunit B (CTB) for extended-distance retro-nerve transporting and long-time neural tracing.

A retrograde transportation nerve probe, Au nanodots-cholera toxin B subunit (AuNDs-CTB), are prepared and fully characterized, which emit bright red fluorescence and show high quantum yield (7.2%) and good stability. The fluorescence emitted by the AuNDs is constant across a wide pH range (4-10) and after prolonged UV irradiation (>4 h). Previously, CTB has shown targeting characteristic for nerve cells with high sensitivity and effectiveness. After linking CTB to AuNDs through amidation reactions, AuNDs-CTB are obtained with excellent fluorescence property, nerve target characteristic, and, particularly, neural retrograde transportation feature. The red emission of the AuNDs-CTB is well distinguished from the blue autofluorescence of normal tissues, which provides potential for detection by naked eyes. Further, the fluorescence emission intensity maintains for 10 days in vivo, suggesting great utility for long-time monitoring and sensing of the nerve tissue. Furthermore, the AuNDs-CTB with bright red fluorescence can travel through the peripheral nerve to the spinal cord rapidly by retrograde transportation. The transportation occurs for a long distance (>5 cm) within only 2 days after injection of the AuNDs-CTB into the sciatic nerve. The present study exhibits a novel method for nerve visualization and drug delivery. STATEMENT OF SIGNIFICANCE: Au nanodots (AuNDs) conjugated with cholera toxin subunit B (CTB) have been developed for nerve labeling and neural retro-transporting. The red fluorescence from AuNDs-CTB is stable in vitro (pH 4-10 and 4 h UV irradiation) and in vivo (for a long time, more than 10 days). When injecting AuNDs-CTB into the sciatic nerve located at the midpiece of the thigh, the targeted nerve emits bright red fluorescence under UV light. Furthermore, the nerve can retrograde transport the AuNDs-CTB to the spinal cord for a distance of more than 5 cm just in 2 days. This work exhibits a novel method for nerve visualization by naked eyes and demonstrates the potential for intraoperative navigation.

Lady with wings: a case report of giant neurofibromatosis type I.

RATIONALE: Neurofibromatosis type I (NF-I) accounts for approximately 90% of neurofibromatosis. NF-I is an autosomal dominant genetic disease which results from the gene mutation of NF-I situated in chromosome 17q11.2. PATIENT CONCERNS: A 32-year-old lady presented with a giant wing like structure on her back which started growing from her childhood. DIAGNOSIS: A diagnosis of NF-I was confirmed as she presented with multiple cutaneous nodules, multiple café-au-lait macules of different sizes, scoliosis deformity, and positive family history of neurofibroma. INTERVENTIONS: Surgical excision of tumor and multiple Z plasty reconstruction of the back was carried out. OUTCOMES: The excised neurofibroma weighed 6.7 kg containing thickened nerves, nerve roots, and circuitous vessels. The histopathological report confirmed plexiform and diffuse type cutaneous neurofibroma without any malignant transformation. Surgical excision and reconstruction with regular follow-up is an excellent choice of treatment for such a giant neurofibroma as in this case. LESSONS: NF-I is a genetic disease which could present as a giant cutaneous neurofibroma. One of the treatment options for giant neurofibromas causing deformity and physical disability is by surgical excision and histopathological examination with regular follow-up for NF-I recurrence.

Reconstruction of the Foot and Ankle Using Pedicled or Free Flaps: Perioperative Flap Survival Analysis.

OBJECTIVE: The purpose of this study is to determine the correlation between non-technical risk factors and the perioperative flap survival rate and to evaluate the choice of skin flap for the reconstruction of foot and ankle. METHODS: This was a clinical retrospective study. Nine variables were identified. The Kaplan-Meier method coupled with a log-rank test and a Cox regression model was used to predict the risk factors that influence the perioperative flap survival rate. The relationship between postoperative wound infection and risk factors was also analyzed using a logistic regression model. RESULTS: The overall flap survival rate was 85.42%. The necrosis rates of free flaps and pedicled flaps were 5.26% and 20.69%, respectively. According to the Cox regression model, flap type (hazard ratio [HR] = 2.592; 95% confidence interval [CI] (1.606, 4.184); P < 0.001) and postoperative wound infection (HR = 0.266; 95% CI (0.134, 0.529); P < 0.001) were found to be statistically significant risk factors associated with flap necrosis. Based on the logistic regression model, preoperative wound bed inflammation (odds ratio [OR] = 11.371,95% CI (3.117, 41.478), P < 0.001) was a statistically significant risk factor for postoperative wound infection. CONCLUSION: Flap type and postoperative wound infection were both independent risk factors influencing the flap survival rate in the foot and ankle. However, postoperative wound infection was a risk factor for the pedicled flap but not for the free flap. Microvascular anastomosis is a major cause of free flap necrosis. To reconstruct complex or wide soft tissue defects of the foot or ankle, free flaps are safer and more reliable than pedicled flaps and should thus be the primary choice.

Neo-digit functional reconstruction of mutilating hand injury using transplantation of multiple composite tissue flaps.

PURPOSE: Functional reconstruction of mutilating hand injuries poses a challenge to the surgeon. We present our experience with use of multiple composite tissue flaps transplant for functional reconstruction of hand in patients with mutilating hand injuries. The associated merits and demerits of these surgical approaches are briefly discussed. METHODS: From August 2004 to October 2014, functional reconstruction of hand with transplantation of multiple composite tissue flaps was performed in 8 patients. These included the toe with dorsal pedis artery flap, the reverse posterior interosseous artery flap, and the anterolateral thigh flap. Mean interval from injury to functional reconstruction was 10.6 days. RESULTS: All transplanted skin flaps and reconstructed neofingers survived completely. Only 1 patient developed wound infection at the recipient site (hand), which resolved without any debridement or revision surgery. At the donor site (foot), partial skin necrosis was observed in 1 patient, which healed with local wound care. In other patients, all wounds healed without any complications. The average range of movement at the neofinger metacarpophalangeal and interphalangeal joints was 38° and 73°, respectively. None of the patients required revision surgery. CONCLUSION: Use of negative pressure wound therapy and multiple composite tissue flap transplantation appears to be an effective strategy for hand functional reconstruction in patients with mutilating hand injuries. Among the multiple composite tissue flaps, use of toe transplantation combined with reverse posterior interosseous artery flap appears to be the best option.

A novel fluorescent retrograde neural tracer: cholera toxin B conjugated carbon dots.

The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde tracers.

The crosslink enhanced emission (CEE) in non-conjugated polymer dots: from the photoluminescence mechanism to the cellular uptake mechanism and internalization.

The crosslink enhanced emission (CEE) in a new type of non-conjugated polymer dots (PDs) is proved. The enhanced PL originates from the decreased vibration and rotation of amino-based chromophores. Furthermore, the cellular uptake mechanism and internalization of PDs were investigated in detail.