The Triple Adipose-Derived Stem Cell Exosome Technology as a Potential Tool for Treating Triple-Negative Breast Cancer.

BACKGROUND: Extracellular vesicles are pivotal mediators in intercellular communication, facilitating the exchange of biological information among healthy, pathological and tumor cells. Between the diverse subtypes of extracellular vesicles, exosomes have unique properties and clinical and therapeutical applications. Breast cancer ranks as one of the most prevalent malignancies across the globe. Both the tumor core and its surrounding microenvironment engage in a complex, orchestrated interaction that facilitates cancer's growth and spread. METHODS: The most significant PubMed literature about extracellular vesicles and Adipose-Derived Stem Cell Exosomes and breast cancer was selected in order to report their biological properties and potential applications, in particular in treating triple-negative breast cancer. RESULTS: Adipose-Derived Stem Cell Exosomes represent a potential tool in targeting triple-negative breast cancer cells at three main levels: the tumor core, the tumor microenvironment and surrounding tissues, including metastases. CONCLUSIONS: The possibility of impacting triple-negative breast cancer cells with engineered Adipose-Derived Stem Cell Exosomes is real. The opportunity to translate our current in vitro analyses into a future in vivo scenario is even more challenging.

[Treatment strategies for fracture-related infections with concurrent soft tissue damage]. / Therapiestrategien bei frakturassoziierten Infektionen mit begleitendem Weichteilschaden.

Fracture-related infections are the predominant complication following surgical fracture treatment. The distal lower leg, e.g., in pilon tibial fractures, is at a high risk of infection due to poor soft tissue coverage, particularly in cases of open fractures in this area. Fracture-related infections with significant soft tissue damage require special attention alongside treatment of the infection itself. In general, the principle is that healing of fracture-related infection is not possible without sufficient soft tissue coverage. Therefore, it is crucial to integrate both soft tissue damage and fracture-related infection into a comprehensive treatment plan from the beginning. An interdiscpilinary treatment approach between trauma and plastic surgery is often necessary and beneficial. In cases, where fracture fixation devices or bone is exposed, mid- or long-term use of vacuum-assisted wound therapy is not advisable due to a higher risk of reinfection. Hence, an interdisciplinary treatment strategy involving trauma and plastic surgery should prioritize early soft tissue closure, referred to as the "orthoplastic approach". If this cannot be done in the own hospital, early patient transfer is indicated to ensure optimal interdisciplinary therapy with early soft tissue closure and simultaneous trauma surgical treatment to control the infection and enable bone healing. Free fasciocutaneous or muscle flap techniques in combination with adequate trauma surgical and antibiotic therapy lead to good reliable results in these situations.

Multidisciplinary Treatment of Fracture-Related Infection Has a Positive Impact on Clinical Outcome-A Retrospective Case Control Study at a Tertiary Referral Center.

OBJECTIVES: Fracture-related infection (FRI) is a major complication in orthopedic and trauma surgery. The management and choice of treatment can be difficult depending on multiple factors. Therefore, we implemented a weekly multidisciplinary team discussion to determine diagnostic and treatment strategies in FRI patients and aimed to analyze its effect on clinical outcomes. METHODS: Clinical outcomes of FRI patients treated before and after implementation of a structured multidisciplinary treatment (MDT) approach with a weekly case discussion were compared at a follow-up of 12 months. RESULTS: In total, n = 117 were eligible for enrolment, whereby n = 58 patients (72.4% male, mean age 56.7 ± 16.8 years) constituted the MDT group and n = 59 patients (72.9% male, mean age 55.0 ± 16.5 years) the control group. In the MDT group more cases were treated with local antibiotics (67.2% vs. 27.1%, p < 0.001) and significant less amputations (3.4% vs. 6.8%, p = 0.014), as well as less revision surgeries (1.5 ± 1.2 (0-5) vs. 2.2 ± 1.2 (0-7), p = 0.048) were performed. A trend towards less debridement, antibiotics and implant retention (DAIR) procedures, lower rates of recurrence of infection and less treatment failures in the MDT group was observable, even though not statistically significant. CONCLUSION: An MDT approach providing a patient tailored treatment concept in the treatment of FRI patients appears to be beneficial for the affected patients. Quality and efficacy of implemented MDT meetings should further be evaluated to provide sufficient evidence to further implement this valuable tool in clinical practice and decision making.

"A-PePSI LIGhT" Assessment Score to Predict Pressure Sore Impaired Healing Late Recurrence, Immobility, Greater Surface, Inhibited Thrombocytes.

BACKGROUND: Complication rates of up to 46 percent are reported following pressure sore surgery. Pressure sore patients often exhibit ineffective postoperative wound healing despite tension-free flap coverage, necessitating surgical revision and prolonged hospitalization. Rather than pressure sore recurrence, such impaired healing reflects a failed progress through the physiologic stages of the normal wound-healing cascade. The principal objective of the study reported here was to elucidate potentially modifiable inherent variables that predict predisposition to impaired healing and to provide a tool for identifying cases at risk for complicated early postoperative recovery following pressure sore reconstruction. METHODS: A retrospective chart review of late-stage (stage 3 or higher) sacral and ischial pressure sore patients who underwent flap reconstruction from 2014 to 2019 was performed. A multivariable logistic regression model was used to identify key patient and operative factors predictive of impaired healing. Furthermore, the Assessment Score to Predict Pressure Sore Impaired Healing (A-PePSI) was established based on the identified risk factors. RESULTS: In a cohort of 121 patients, 36 percent exhibited impaired healing. Of these, 34 patients suffered from dehiscences, necessitating surgical revision. Statistically significant risk factors comprising late recurrence (OR, 3.8), immobility (OR, 12.4), greater surface (>5 cm diameter; OR, 7.3), and inhibited thrombocytes (aspirin monotherapy; OR, 5.7) were combined to formulate a prognostic scoring system (A-PePSI LIGhT). CONCLUSIONS: The A-PePSI LIGhT score serves as a prognostic instrument for assessing individual risk for impaired healing in pressure sore patients. Preoperative risk stratification supports rational decision-making regarding operative candidacy, allows evidence-based patient counseling, and supports the implementation of individualized treatment protocols. . CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Indocyanine Green for Leakage Control in Isolated Limb Perfusion.

Sarcomas are characterized by a high metastatic potential and aggressive growth. Despite surgery, chemotherapy plays an important role in the treatment of these tumors. Optimal anti-cancer therapy with maximized local efficacy and minimized systemic side effects has been the object of many studies for a long time. To improve the local efficacy of anti-tumor therapy, isolated limb perfusion with high-dose cytostatic agents has been introduced in surgical oncology. In order to control the local distribution of substances, radiolabeled cytostatic drugs or perfusion solutions have been applied but often require the presence of specialized personnel and result in a certain exposure to radiation. In this study, we present a novel strategy using indocyanine green to track tumor perfusion with high-dose cytostatic therapy. In a rat cadaver model, the femoral vessels were cannulated and connected to a peristaltic pump to provide circulation within the selected limb. The perfusion solution contained indocyanine green and high-dose doxorubicin. An infrared camera enabled the visualization of indocyanine green during limb perfusion, and subsequent leakage control was successfully performed. Histologic analysis of sections derived proximally from the injection site excluded systemic drug dispersion. In this study, the application of indocyanine green was proven to be a safe and cost- and time-efficient method for precise leakage control in isolated limb perfusion with a high-dose cytostatic agent.

Local Triamcinolone Treatment Affects Inflammatory Response in Seroma Exudate of Abdominoplasty Patients: A Randomized Controlled Trial.

BACKGROUND: As the leading complication of abdominoplasty, seroma formation might represent an inflammatory process in response to surgical trauma. This prospective randomized trial investigated whether local administration of the antiinflammatory agent triamcinolone could prevent seroma accumulation. METHODS: Weekly and cumulative seroma volumes were compared between the study groups A, B, and C over a 4-week follow-up (group A, with drain, without triamcinolone; group B, without drain, without triamcinolone; group C, without drain, with triamcinolone). Aspirated seroma samples were analyzed by enzyme-linked immunosorbent assay for selective inflammatory mediators. RESULTS: Triamcinolone significantly reduced cumulative seroma volume (n = 60; mA 845 ± SDA 578 ml, mC 236 ± SDC 381 ml, p = 0.001). The most accentuated suppressive effect of triamcinolone was observed shortly after the treatment (week 1) (mA1 616 ± SDA1 457 ml, mB1 153 ± SDB1 161 ml, mC1 22 ± SDC1 44 ml, pA1/C1 < 0.001, pB1/C1 = 0.014). Local triamcinolone administration resulted in a differential concentration of interleukin-6 (IL-6) and matrix metalloproteinase-9 (MMP-9 (week 1) in seroma exudate as measured by enzyme-linked immunosorbent assay (mIL-6A1 1239 ± SDA1 59 pg/ml, mIL-6C1 848 ± SDC1 80 pg/ml, p < 0.001; mMMP-9A1 2343 ± SDA1 484 pg/ml, mMMP-9C1 376 ± SDC1 120 pg/ml, p = 0.001). CONCLUSIONS: Local administration of 80 mg of triamcinolone reduced postabdominoplasty seroma accumulation significantly. Under triamcinolone treatment, suppressed levels of IL-6 and MMP-9 in seroma fluid were observed. Notably, inflammatory marker suppression correlated clinically with a decrease in seroma accumulation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Extracorporeal perfusion - reduced to a one-way infusion.

BACKGROUND: Extracorporeal perfusion (EP) is moving into focus of research in reconstructive and transplantation medicine for the preservation of amputates and free tissue transplants. The idea behind EP is the reduction of ischemia-related cell damage between separation from blood circulation and reanastomosis of the transplant. Most experimental approaches are based on a complex system that moves the perfusate in a circular course. OBJECTIVE AND METHODS: In this study, we aimed to evaluate if a simple perfusion by an infusion bag filled with an electrolyte solution can provide acceptable results in terms of flow stability, oxygen supply and viability conservation for EP of a muscle transplant. The results are compared to muscles perfused with a pump system as well as muscles stored under ischemic conditions after a one-time intravasal flushing with Jonosteril. RESULTS: With this simple method a sufficient oxygen supply could be achieved and functionality could be maintained between 3.35 times and 4.60 times longer compared to the control group. Annexin V positive nuclei, indicating apoptosis, increased by 9.7% in the perfused group compared to 24.4% in the control group. CONCLUSIONS: Overall, by decreasing the complexity of the system, EP by one-way infusion can become more feasible in clinical situations.

Early fasciotomies and plastic-surgical reconstruction may enhance preservation of functional extremity length in purpura fulminans.

BACKGROUND: Purpura fulminans (PF) is a distinct form of rare meningococcal septicaemia mostly in childhood which is characterized by high lethality, extensive necroses and mutilations of extremities. Other ethiologies are idiopathic forms or purpura neonatorum, which is marked by deficiency of Protein-C. PF is caused by micro-embolism of the vascular system, followed by quickly spreading necroses of skin and different organs.Modern concepts of intensive care treatment of the acute phase of this disease and early surgical intervention lead to a rising number of surviving patients requiring limb salvage.Aim of this study is to evaluate a possible lower morbidity and the grade of lower loss of function because of early surgical intervention. PATIENTS AND METHODS: Between the years 1998 and 2017 eight cases of PF at two large centers for critical wound care, the department of plastic-, hand- and reconstructive surgery of the university hospital of Regensburg and the department of plastic-, hand- and reconstructive surgery of the BG-clinic Ludwigshafen were included into our study.We retrospectively examined patients with PF who were stabilized by intensive care medicine and received surgical interventions. After survival of the acute phase (10 days), patients received plastic surgical reconstructions. RESULTS: A total number of eight patients could be included into our study. All patients survived the initial phase (10 days). All patients required plastic-surgical interventions to address extensive skin and soft tissue defects. Flap operations were judged necessary in five cases. Hereby four defects could be reconstructed by free tissue transfer, one with a local flap. Flap survival was 100 percent. One flap required revision of the arterial anastomosis of the flap arteria. Another flap got partial necrosis. One patient died due to multiorgan failure.Early debridements with consequent fasciotomies and secondary plastic-surgical reconstruction achieved good functional results. Limb salvage was accomplished in three patients. One patient died due to fulminant progress of the disease. CONCLUSION: Management of PF requires a multidisciplinary approach and close communication between the different subspecialties. Early debridements with consequent fasciotomies showed good results in salvaging subfascial muscle tissue in the extremities with satisfying functional results. Early surgical intervention is an important factor for improved limb salvage and survival.

Significance of the Marginal Mandibular Branch in Relation to Facial Palsy Reconstruction: Assessment of Microanatomy and Macroanatomy Including Axonal Load in 96 Facial Halves.

BACKGROUND: The marginal mandibular branch (MMB) of the facial nerve provides lower lip symmetry apparent during human smile or crying and is mandatory for vocal phonation. In treating facial palsy patients, so far, little attention is directed at the MMB in facial reanimation surgery. However, isolated paralysis may occur congenital, in Bell's palsy or iatrogenic during surgery, prone to its anatomical course. A variety of therapies address symmetry with either weakening of the functional side or reconstruction of the paralyzed side. To further clarify the histoanatomic basis of facial reanimation procedures using nerve transfers, we conducted a human cadaver study examining macroanatomical and microanatomical features of the MMB including its axonal capacity. METHODS: Nerve biopsies of the MMB were available from 96 facial halves. Histological processing, digitalization, nerve morphometry investigation, and semiautomated axonal quantification were performed. Statistical analysis was conducted with P < 0.05 as level of significance. RESULTS: The main branch of 96 specimens contained an average of 3.72 fascicles 1 to 12, and the axonal capacity was 1603 ± 849 (398-5110, n = 85). Differences were found for sex (P = 0.018), not for facial sides (P = 0.687). Diameters were measured with 1130 ± 327 µm (643-2139, n = 79). A significant difference was noted between sexes (P = 0.029), not for facial sides (P = 0.512.) One millimeter in diameter corresponded to 1480 ± 630 axons (n = 71). A number of 900 axons was correlated with 0.97 mm (specificity, 90%; sensitivity, 72%). CONCLUSIONS: Our morphometric results for the MMB provide basic information for further investigations, among dealing with functional reconstructive procedures such as nerve transfers, nerve grafting for direct neurotization or babysitter procedures, and neurectomies to provide ideal power and authenticity.

Transcutaneous oxygen measurement using ratiometric fluorescence imaging as a valid method for monitoring free flap transplants.

BACKGROUND: Reconstruction of soft tissue defects with free flaps is a common procedure in plastic and reconstructive surgery. Most postoperative complications occur within the first 48-72 hours after surgery. After postoperative complications, short perfusion restoration times may improve flap survival rates by up to 30-50%. Ratiometric fluorescence imaging is an additional or alternative method of postoperative flap monitoring. OBJECTIVE: To test the efficacy and utility of transepidermal oxygen flux imaging to evaluate postoperative skin oxygenation of free and local flaps in the first 48 hours after surgery. METHODS: The study included 32 patients (aged between 18 and 80 years; mean age 52.9) with a tissue defect covered with a free flap transplant at the Department of Plastic and Reconstructive Surgery of the University Medical Center Regensburg. Postoperative oxygen flux was measured with the 'VisiSens system' placed on the vascular pedicle as well as on the peripheral and central part of the flap. RESULTS: Values of oxygen flux were higher in case of flap congestion (0.069±0.012) or flap necrosis (0.155±0.083) than in cases without any complications (0.061±0.006). Flux values of different areas of the same flap showed only minimal differences (central part: 0.065±0.008, peripheral part: 0.070±0.009, vascular pedicle: 0.056±0.004); the level of significance was p = 0.904. CONCLUSION: Imaging transepidermal oxygen flux by ratiometric luminescence seems to be a reliable alternative, indirect method of postoperative flap monitoring with regard to microcirculatory function and flap viability.

Reconstruction of chronic scapholunate dissociation with the modified scapholunate axis method (SLAM).

INTRODUCTION: Injury to the scapholunate (SL) ligament represents a common trauma of the wrist but is frequently misdiagnosed because of non-specific pain. Established methods for SL reconstruction mainly focus on reducing pain and maintaining the reposition result at the expense of mobility and strength. This study aimed at restoring stability and reducing pain while simultaneously maintaining mobility and strength using the scapholunate axis method (SLAM). MATERIAL AND METHODS: 22 patients (19 male and 3 female) aged between 26 and 64 years with an SL ligament lesion underwent SLAM reconstruction. Mean duration between injury and operation was 7.9 ± 5 (1-24) months. Hand functions using DASH, Mayo Wrist Score, range of motion, pain (at rest and weight-bearing) and grip strength were assessed prior and 12 months postoperative. Additionally SL angle was collected pre- and postoperative. RESULTS: Each of the 22 patients improved significantly postoperative in DASH and Mayo Wrist Score with regard to pain at rest and under weight-bearing. Additionally, grip strength could be improved up to 31% compared to preoperatively. In contrast, range of motion and SL angle and grip strength did not change essentially. CONCLUSIONS: The secondary SL ligament reconstruction technique SLAM shows promising results. Pain was significantly relieved and grip strength was significantly increased. Additionally, DASH and Mayo Wrist Score could be significantly improved. However, SL angle and range of motion could not be improved in every patient and plane.

[Modified SLAM (scapholunate axis method) technique for secondary SL reconstruction: preliminary results]. / Die modifizierte SLAM (scapholunate axis method) Technik zur sekundären SL-Band-Rekonstruktion ­ Erste Ergebnisse.

BACKGROUND: The common techniques for scapholunate (SL) ligament reconstruction achieve pain relief and maintenance of reposition at the expense of mobility and grip strength. In contrast, the scapholunate axis method (SLAM) technique seems to stabilise the scaphoid and lunate bones without a loss of function. We modified the technique with an additional anchor fixation of the tendon graft to the capitate bone in order to prevent palmar dislocation of the scaphoid bone. PURPOSE: This study aimed to examine whether or not it is possible to stabilise the scaphoid and lunate bones and to reduce pain without a loss of function and grip strength using the modified SLAM technique. PATIENTS AND METHODS: The SLAM technique was performed on 5 male patients aged between 36 and 60 years with an SL ligament lesion (3-10 months old). Preoperatively and after 12 months, the postoperative range of motion, grip strength, pain, SL angle, DASH Score and Mayo Wrist Score were assessed and compared to each other. RESULTS: An improvement of the DASH Score (60.4 to 34.4 on average) and the Mayo Wrist Score (41 to 74 on average) was observed at the 12-month follow-up. Grip strength was enhanced from an average of 24.6 kg to 38 kg. Pain was improved from an average of 1.4 to 0.2 (at rest) and from 5.4 to 1.4 (under load). The SL angle changed only marginally from an average of 64.8° preoperatively to 63.2° postoperatively. The average range of motion was improved (extension/flexion: 58-0-60 vs. 50-0-49; radial/ulnar duction: 19-0-45 vs. 15-0-25 und supination/pronation: 87-0-90 vs. 81-0-81): However, function did not improve in every patient and all planes. CONCLUSION: The modified SLAM technique improved the DASH Score, the Mayo Wrist Score, grip strength and pain. However, the SL angle and range of motion did not improve in every patient and plane. Consequently, it cannot be confirmed that the modified SLAM technique ensures a reliable stabilisation of the scaphoid and lunate bones and reduction of pain without a loss of function.

Anatomical study of the zygomatic and buccal branches of the facial nerve: Application to facial reanimation procedures.

The facial nerve is responsible for any facial expression channeling human emotions. Facial paralysis causes asymmetry, lagophthalmus, oral incontinence, and social limitations. Facial dynamics may be re-established with cross-face-nerve-grafts (CFNG). Our aim was to reappraise the zygomaticobuccal branch system relevant for facial reanimation surgery with respect to anastomoses and crossings. Dissection was performed on 106 facial halves of 53 fresh frozen cadavers. Study endpoints were quantity and relative thickness of branches, correlation to "Zuker's point", interconnection patterns and crossings. Level I and level II branches were classified as relevant for CFNG. Anastomoses and fusion patterns were assessed in both levels. The zygomatic branch showed 2.98 ± 0.86 (range 2-5) twigs at level II and the buccal branch 3.45 ± 0.96 (range 2-5), respectively. In the zygomatic system a single dominant branch was present in 50%, two co-dominant branches in 9% and three in 1%. In 66% of cases a single dominant buccal twig, two co-dominant in 12.6%, and three in 1% of cases were detected. The most inferior zygomatic branch was the most dominant branch (P = 0.003). Using Zuker's point, a facial nerve branch was found within 5 mm in all facial halves. Fusions were detected in 80% of specimens. Two different types of fusion patterns could be identified. Undercrossing of branches was found in 24% at levels I and II. Our study describes facial nerve branch systems relevant for facial reanimation surgery in a three-dimensional relationship of branches to each other. Clin. Anat. 32:480-488, 2019. © 2019 Wiley Periodicals, Inc.

Video Tutorial for Clinical Flap-Monitoring in Plastic Surgery.

Supplemental Digital Content is available in the text.

Postoperative control of functional muscle flaps for facial palsy reconstruction: Ultrasound guided tissue monitoring using contrast enhanced ultrasound (CEUS) and ultrasound elastography.

BACKGROUND AND OBJECTIVES: Facial paralysis causes excruciating impairments including facial asymmetry, limited eye closure, oral incontinence and social dysfunction. Modern plastic surgical reconstructions render favorable results with well-perfused dynamic muscle flaps. Post-operative tissue monitoring is a critical determinant for success. Contrast-enhanced Ultrasound (CEUS) and elastography have proven superior properties to evaluate tissue perfusion in various organs. We evaluated their role for functional muscle flaps positioned at the sub-skin level in facial palsy patients. METHODS: From 2016-2017 five patients received muscle flap reconstructions. Flaps included four free transplants and one pedicled transfer. Postoperatively tissue vitality and blood flow were assessed with CEUS. One experienced examiner using linear probes (6-9, 6-15 MHz) and bolus injections of Sulphur-hexafluoride microbubbles evaluated tissue perfusion. Using the time intensity curve- (TIC)-analysis measurements were recorded for TTP (time to peak) and AUC (Area under curve). Tissue elasticity was assessed with ultrasound elastography. RESULTS: All flaps were successful and showed no major complications. TTP-values in flap tissue showed slightly decreased values of 35.12±33.99 s and 25.04±10.86 s compared to surrounding tissue with 19.88±6.94 s. AUC-analysis however revealed higher values of 292.25±169.52 RU and 274.51±115.88 RU than surrounding tissue with 150.90±40.21 RU. Elastography demonstrated predominantly elastic flap tissue whereas surrounding tissue confirmed a slightly harder tissue quality. CEUS in combination with elastography verified tissue vitality and blood flow in a safe and reproducible manner. CONCLUSIONS: Post-operative perfusion monitoring in muscle flaps positioned at a sub-skin level may be performed superiorly by CEUS and elastography in a quick, reproducible and minimally-invasive fashion.

Contrast-enhanced ultrasonography as a new method for assessing autonomization of pedicled and microvascular free flaps in head and neck reconstructive surgery.

OBJECTIVE: Evaluating vascular autonomization of pedicled and microvascular free flaps for soft tissue reconstruction in the head and neck area by means of postoperative quantitative measurement of dynamic contrast values obtained with contrast-enhanced ultrasound. METHODS: 8/18 patients underwent lip reconstruction with a pedicle flap, 10 patients reconstruction of other parts of the head with a microvascular free transplant. Ultrasound examinations were conducted within the 1st postoperative week and 4 weeks after surgery. After the intravenous bolus of the ultrasound contrast agent, examinations were carried out for 30 sec without compression followed by 30 sec with compression of the vascular pedicle in bolus and flash kinetics. Digital cine loops were analyzed off-line with a quantification software (VueBox™) to determine the Rise Time (RT) between flap tissue with and without compression. RESULTS: Measurements showed increasing autonomous perfusion, independent of the vascular pedicle. No transplant was lost, but 4/10 patients with a microvascular flap and 1/8 patients with a pedicle flap developed postoperative complications. RT values for the pedicled and microvascular flaps obtained under compression differed significantly between the 1st and the 4th week (p = 0.025). CONCLUSIONS: Reliable neovascularization was achieved 4 weeks postoperatively. CEUS showed to be a useful method for assessing the degree of autonomization of pedicle and microvascular free flaps.

Peripheral Motor and Sensory Nerve Conduction following Transplantation of Undifferentiated Autologous Adipose Tissue-Derived Stem Cells in a Biodegradable U.S. Food and Drug Administration-Approved Nerve Conduit.

BACKGROUND: Conduits preseeded with either Schwann cells or stem cells differentiated into Schwann cells demonstrated promising results for the outcome of nerve regeneration in nerve defects. METHODS: The concept of this trial combines nerve repair by means of a commercially available nerve guidance conduit and preseeding with autologous, undifferentiated, adipose tissue-derived stem cells. Adipose tissue-derived stem cells were harvested from rats and subsequently seeded onto a U.S. Food and Drug Administration-approved type I collagen conduit. Sciatic nerve gaps 10 mm in length were created, and nerve repair was performed by the transplantation of either conduits preseeded with autologous adipose tissue-derived stem cells or acellular (control group) conduits. After 6 months, the motor and sensory nerve conduction velocity were assessed. Nerves were removed and examined by hematoxylin and eosin, van Gieson, and immunohistochemistry (S100 protein) staining for the quality of axonal regeneration. RESULTS: Nerve gaps treated with adipose tissue-derived stem cells showed superior nerve regeneration, reflected by higher motor and sensory nerve conduction velocity values. The motor and sensory nerve conduction velocity were significantly greater in nerves treated with conduits preseeded with adipose tissue-derived stem cells than in nerves treated with conduits alone (p < 0.05). Increased S100 immunoreactivity was detected for the adipose tissue-derived stem cell group. In this group, axon arrangement inside the conduits was more organized. CONCLUSIONS: Transplantation of adipose tissue-derived stem cells significantly improves motor and sensory nerve conduction velocity in peripheral nerve gaps. Preseeded conduits showed a more organized axon arrangement inside the conduit in comparison with nerve conduits alone. The approach used here could readily be translated into a clinical therapy. CLINCAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Recommendations for contrast enhanced ultrasound (CEUS) in free tissue transplant monitoring.

Complications rates after free flap transplantation still amount up to 5% . Consequently a reliable monitoring system is of high importance in plastic and reconstructive surgery. The following guidelines provide an overview of the current opportunities for free flap planning and monitoring with ultrasound and in particular with contrast enhanced ultrasound.