Prevention of Allograft Rejection by Use of Regulatory T Cells With an MHC-Specific Chimeric Antigen Receptor.

CD4+ CD25high FOXP3+ regulatory T cells (Tregs) are involved in graft-specific tolerance after solid organ transplantation. However, adoptive transfer of polyspecific Tregs alone is insufficient to prevent graft rejection even in rodent models, indicating that graft-specific Tregs are required. We developed a highly specific chimeric antigen receptor that recognizes the HLA molecule A*02 (referred to as A2-CAR). Transduction into natural regulatory T cells (nTregs) changes the specificity of the nTregs without alteration of their regulatory phenotype and epigenetic stability. Activation of nTregs via the A2-CAR induced proliferation and enhanced the suppressor function of modified nTregs. Compared with nTregs, A2-CAR Tregs exhibited superior control of strong allospecific immune responses in vitro and in humanized mouse models. A2-CAR Tregs completely prevented rejection of allogeneic target cells and tissues in immune reconstituted humanized mice in the absence of any immunosuppression. Therefore, these modified cells have great potential for incorporation into clinical trials of Treg-supported weaning after allogeneic transplantation.

Does an Early and Aggressive Combined Wrapping and Dangling Procedure Affect the Clinical Outcome of Lower Extremity Free Flaps?-A Randomized Controlled Prospective Study Using Microdialysis Monitoring.

Background The ideal starting point for flap training (FT) with the combined wrapping and dangling procedure is still a question of debate. Most units follow their own established protocols and currently evidence of flap compromise due to FT is still lacking. The aim of this study was to prove if an early and "aggressive" wrapping and dangling protocol could lead to metabolic changes, measured by microdialysis, indicating ischemia resulting in compromised flap perfusion. Methods Between 2010 and 2014, 49 patients with microvascular free flap reconstruction of the lower limb were included in this study. Patients were randomized into two groups. Group I started FT on the 7th postoperative day, and group II started on day 3. FT consisted of a combined wrapping and dangling procedure doubling its duration daily and ending at day 5. Flaps were monitored clinically and by microdialysis for ischemia-induced changes and metabolic parameters in the flap tissue in respect to different starting points of FT. Results All 49 patients in both groups were able to complete the postoperative FT without complications. Noninferiority of the early group could be proven and microdialysis results showed no differences between both groups. Conclusion We could prove by microdialysis that an early start of FT does not lead to compromised flap perfusion. Moreover, an early start of FT can lead to a reduced length of hospital stay. Furthermore, a reduced risk for deep vein thrombosis, pulmonary embolism, and pneumonia due to earlier mobilization might be an appreciated side effect.

[Impact of Martian and Lunar dust simulants on cellular inflammation in human skin wounds ex vivo]. / Einfluss von Mars- und Mondstaubanaloga auf die Wundheilung humaner Haut im ex-vivo Modell.

BACKGROUND: In 2006 NASA published its plans to build a manned lunar station in order to undertake missions to Mars in the future. Thus research projects have been conducted on the influence of Lunar and Martian dust on human health. The present study investigated the effect of Lunar and Martian dust simulants (LDS, MDS) in comparison with earth dust (ED) on viability, migration and inflammatory reaction during wound closure in an ex vivo human skin wound model. MATERIALS AND METHODS: 6 mm full-thickness skin explants, with a central 3 mm epidermal wound were cultured with LDS, MDS or ED for 4 and 8 days and compared to wound closure without dust exposure. Tissue and conditioned medium were submitted to histological, immunohistochemical (Ki67, Caspase-3) and biochemical analyses (hydroxyproline assay, zymography, IL-6, TNF-α and TGF-ß ELISA). RESULTS: All dusts increased proinflammatory markers with significant increases in MDS-treated samples (IL-6: p<0.05; MMP-9: p<0.005) and reduced MMP-2 (p<0.05) compared to no dust controls over time. No significant differences were found regarding wound closure, proliferation, apoptosis and tissue degradation. CONCLUSION: Highly oxidative Martian dust may cause increased cutaneous inflammation. As is currently advocated for wounds contaminated with earth dust, surgical wound debridement should be performed to ensure uncompromised wound healing.

Early start of the dangling procedure in lower extremity free flap reconstruction does not affect the clinical outcome.

UNLABELLED: Flap loss due to postoperative flap edema and thrombosis of the anastomosis remains the predominant concern of reconstructive microsurgeons. Due to the lack of scientific evidence, there is no unanimous opinion on when to mobilize a reconstructed lower extremity, reflecting the uncertainty of plastic surgeons regarding the effect of the dangling procedure on flap microcirculation. PATIENTS AND METHODS: In this randomized controlled clinical trial, we included 31 patients undergoing free flap transfer to the lower extremity.The patients were randomly divided into two groups. Cohort I consisted of 15 patients starting the dangling procedure at day 7, and cohort II consisted of 16 patients in which an early aggressive postoperative dependency started at day 3.Wrapping and dangling of the flap was performed primarily with a duration of 5 minutes three times a day and increased daily by doubling the duration over a period of 4 days, reaching 60 minutes at day 5.Before and immediately after each dangling procedure the flaps were clinically monitored under direct observation for color, capillary refill, venous congestion, flap turgor, and flap temperature. RESULTS: In all cases the postoperative course was uneventful, resulting in a success rate of 100%. No adverse effects or flap compromise were seen due to the combined dangling/wrapping procedure. CONCLUSION: An early and aggressive start of a combined dangling/wrapping procedure does not compromise flap circulation and allows mobilizing patients after free flap transfer to the lower extremity at an early stage. This approach improves patient comfort, shortens the hospital stay, and therefore reduces socioeconomic costs.

[One-stage defect closure of deperiosted bone and exposed tendons with MATRIDERM® and skin transplantation. Possibilities and limitations]. / Einzeitige Defektdeckung von denudiertem Knochen und freiliegenden Sehnen mittels MATRIDERM® und Spalthaut. Möglichkeiten und Grenzen.

BACKGROUND: Full-thickness skin defects over functional structures (tendons, vessels) or deperiosted bones of the extremities usually require extensive soft tissue reconstruction to cover the defect. A new option for coverage of the defect is the application of MATRIDERM®, a bovine matrix consisting of collagen and elastin, as a neodermis underneath skin transplants. Can this combined one-stage surgical intervention successfully cover deperiosted bone or tendon? PATIENTS AND METHODS: We performed this one-stage procedure in ten patients instead of soft tissue reconstruction. The success of wound coverage with the one-stage method and in combination with skin transplantation for defects generally associated with considerable loss of transplants (deperiosted bones and tendons without paratenons) was determined. RESULTS: In nine of ten patients, complete defect coverage could be achieved. A one-stage wound closure in extensive defects with exposed tendons in four of five locations could be achieved. In deperiosted bone defects the one-stage coverage was only successful in two of six patients. However, complete wound closure could be achieved with a second skin transplantation in a patient with exposed tendon and bone in three of the four locations. CONCLUSION: As a one- or two-stage procedure, MATRIDERM® application with skin transplantation resulted in an effective defect closure without the need for a complex plastic reconstructive procedure. With regard to its functionality it cannot be considered as a substitute for skin flaps. In selected cases MATRIDERM® is an interesting and successful method in plastic reconstructive surgery.

[Perioperative coagulation management in microsurgery: report of the consensus workshops in the course of the 31st and 32nd Annual Meeting of the German-language Working Group for microsurgery of the peripheral nerves and vessels (DAM) November 2009 in Erlangen and November 2010 in Basel]. / Perioperatives Gerinnungsmanagement in der Mikrochirurgie - Bericht der Konsensus-Workshops im Rahmen der 31. und 32. Jahrestagung der Deutschsprachigen Arbeitsgemeinschaft für Mikrochirurgie der peripheren Nerven und Gefäße (DAM) im November 2009 in Erlangen und November 2010 in Basel.

Microsurgery is a very relevant component of reconstructive surgery. In this context anticoagulation plays an increasing role. At the moment there are no unanimously accepted prospective studies or generally accepted regimes available that could serve as evidence-based guidelines for the prevention of thrombosis in microsurgery. With regard to this problem the aim of a series of workshops during the annual meetings of the German-speaking group for microsurgery in 2009 and 2010 was to establish a first possible consensus. This article reflects the main aspects of the ongoing development of a generally acceptable guideline for anticoagulation in microsurgery as interim report of these consensus workshops. Basically there are 3 main agents in thromboprophylaxis available: antiplatelet drugs, dextran and heparin. In the course of the workshops no general use of aspirin or dextran for anticoagulation in microsurgery was recommended. The use of heparin as anticoagulation agent is advisable for different indications. Low molecular heparins (LMH) have certain advantages in comparison to unfractionated heparins (UFH) and are therefore preferred by most participants. Indications for UFH are still complex microsurgical revisions, renal failure and some specific constellations in patients undergoing reconstruction of the lower extremity, where the continuous administration of heparin is recommended. At the moment of clamp release a single-shot of UFH is still given by many microsurgeons, despite a lack of scientific evidence. Future prospective clinical trials and the establishment of a generally accepted evidence-based guideline regarding anticoagulation treatment in microsurgery are deemed necessary.

[The current evidence-based guidelines regarding prophylaxis of venous thrombembolism and their relevance for plastic surgery]. / Die aktuelle S3-Leitlinie zur Prophylaxe der venösen Thromboembolie und ihre Implikation für die Plastische Chirurgie.

INTRODUCTION: In Germany, clinically and experimentally proven, evidence-based guidelines for the perioperative prophylaxis of thromboembolism in plastic surgery have not yet been developed. The ever-expanding complexity of microsurgical reconstructive procedures associated with the immense technical progress in the medical field have once more highlighted the urgent need for evidence-based guidelines. Moreover, this urgency is underlined by more and more complex reconstructive procedures needing to be performed in elderly patients presenting with grave comorbidities and the related high risk for thromboembolic events. These facts prompted us to review and discuss the relevance of the updated S3-guidelines on prophylaxis of venous thromboembolic events for the field of plastic and reconstructive surgery . MATERIAL AND METHODS: The existing S3-guidelines represent the result of a consensus between 27 medical societies and organisations. Delegates of the German Society of Plastic, Reconstructive and Aesthetic Surgery (DGPRAEC) also participated in this consensus process and the development of the guidelines, which provide evidence-based and clinically oriented recommendations for the prophylaxis of venous thromboembolism for operative and non-operative as well as outpatient and inpatient settings. In the results section of this paper, general and specific recommendations with regard to plastic and reconstructive surgery are outlined. RESULTS: Indications for the pharmacological prophylaxis of thromboembolic events are oriented on the specific risk categories for surgical interventions with regard to the dispositional individual risk factors. Furthermore, the recommendations for the field of plastic and reconstructive surgery are subdivided into the various regions of the body. DISCUSSION: Evidence-based recommendations for perioperative prophylaxis of venous thromboembolism in plastic surgery are not available yet. The establishment of an algorithm to screen and estimate the procedure-associated risks for thromboembolism is needed. The discussed S3-guidelines of the AWMF Society on the prophylaxis of venous thromboembolism meet these formal requirements. Gathering of evidence-based data and the generation of recommendations leading to a reduction of the perioperative risk of thromboembolic events is a pivotal element to improve patient outcomes and safety in microsurgery.

[Advanced malignant soft tissue tumors: plastic reconstructive options for palliative treatment]. / Fortgeschrittene maligne Weichgewebstumoren: Plastisch-rekonstruktive Möglichkeiten in der palliativen Behandlung.

Plastic and reconstructive procedures for the oncological treatment of malignant tumors in the head and neck region, trunk and extremities are primarily curative. Less is known about the treatment options of plastic surgery in patients with locally advanced or incurable tumors. Therefore superficial, mostly exulcerated and superinfected tumors are treated with a palliative approach. A plethora of symptoms drastically restricts the quality of life in patients with advanced cancer. Pain, oozing of blood and bacterial superinfection with fetidness compromise the patient's general condition, self-esteem and activity. Many patients suffer from increasing isolation. A stage-adapted and plastic-reconstructive approach aiming at reducing the tumor mass and closing ulcerating wounds provides a considerable benefit especially in these patients. In this article a variety of treatment options regarding palliative resections and plastic reconstructive procedures and the disease alleviating benefits for patients with incurable tumors are presented.

[Surgical intensive care medicine. Current therapy concepts for septic diseases]. / Chirurgische Intensivmedizin. Aktuelle Therapiekonzepte septischer Erkrankungen.

The clinical appearance of septic disorders is characterized by an enormous dynamic. The sepsis-induced dysbalance of the immune system necessitates immediate and aggressive therapeutic interventions to prevent further damage progression of the disease to septic shock and multiple organ failure. This includes supportive therapy to normalize and maintain organ and tissue perfusion as well as the identification of the infection focus. In cases where an infectious focus is identified, surgical source control frequently is a key element of the treatment strategy besides pharmacologic and supportive measures. The integrative approach of the management of septic patients requires rapid communication between the involved medical disciplines and the nursing personnel. Therefore, this article outlines current therapeutic concepts of septic diseases as well as central nursing aspects.

Spider silk fibres in artificial nerve constructs promote peripheral nerve regeneration.

OBJECTIVE: In our study, we describe the use of spider silk fibres as a new material in nerve tissue engineering, in a 20-mm sciatic nerve defect in rats. MATERIALS AND METHODS: We compared isogenic nerve grafts to vein grafts with spider silk fibres, either alone or supplemented with Schwann cells, or Schwann cells and matrigel. Controls, consisting of veins and matrigel, were transplanted. After 6 months, regeneration was evaluated for clinical outcome, as well as for histological and morphometrical performance. RESULTS: Nerve regeneration was achieved with isogenic nerve grafts as well as with all constructs, but not in the control group. Effective regeneration by isogenic nerve grafts and grafts containing spider silk was corroborated by diminished degeneration of the gastrocnemius muscle and by good histological evaluation results. Nerves stained for S-100 and neurofilament indicated existence of Schwann cells and axonal re-growth. Axons were aligned regularly and had a healthy appearance on ultrastructural examination. Interestingly, in contrast to recently published studies, we found that bridging an extensive gap by cell-free constructs based on vein and spider silk was highly effective in nerve regeneration. CONCLUSION: We conclude that spider silk is a viable guiding material for Schwann cell migration and proliferation as well as for axonal re-growth in a long-distance model for peripheral nerve regeneration.

[Early surgical management of severe burns]. / Primäre chirurgische Therapie bei Verbrennungen.

The success of modern burn therapy is based on an understanding of the pathophysiology and application of burn intensive care implying fluid resuscitation and management of pulmonary or other organ failure. With the development of early eschar excision and wound closure by immediate grafting, survival and cosmetic outcome were further improved. Especially in post-acute therapy, early physical rehabilitation, early reintegration, and early plastic surgical correction of the sequelae are indispensable for the outcome.

[Plastic reconstruction of postoncologic defects in the pelvic area]. / Plastische Rekonstruktion im Rahmen onkologischer Therapieverfahren: Beckenregion.

The surgical management of defects in the pelvic region is a great surgical challenge. Primary tumor recurrences have to be addressed and local infections require appropriate therapy such as rigorous debridement and antibiotic therapy. Plastic surgery provides tissue reconstruction by well perfused flaps and also reestablishment of anatomic structures in the ano-genital region. An early reconstruction also reduces the wound complications of adjuvant or post oncologic therapy and reduces the rate of wound healing problems.

[Breast cancer -- plastic surgical strategies for the treatment of tumour infiltration of the thoracic wall and brachial plexus]. / Mammakarzinom: Plastisch-chirurgische Strategie bei ausgedehnten Thoraxwandrezidiven und Infiltration des Plexus brachialis.

Extensive locoregional recurrency or metastatic involvement of brachial plexopathy is a condition that is often associated with advanced systemic breast cancer. In the past the role of surgeon was restricted due to a scepticism as to whether any benefit will be provided for the patient. In the recent 25 years however safe and refined plastic surgical approaches have been developed that provide more options to treat even complex recurrent disease. The strategy of plastic surgery in an interdisciplinary approach of gynecology, oncology and radiotherapy as well as thoracic surgery is outlined.

[Plasma concentration of endothelin-1 after myocutaneous latissimus dorsi-transplantation -- role in reperfusion injury]. / Plasmakonzentrationen von Endothelin-1 nach myokutaner Latissimus dorsi-Transplantation -- Bedeutung für den Reperfusionsschaden.

The success of a free flap transplantation is based on a sufficient microanastomosis which meets the following requirements: a pedicle placed without kinking or twisting, a good drainage, a well defined recipient vessel and integrity of the endothelium. The aim of this study was to determine whether operation-related ischaemia through flap transplantation and tourniquet induces an increase of Endothelin-1 plasma levels as one cause of vasospasm during microvascular procedures. We focused our attention in particular on the reperfusion period which is often limited to an irreversible perfusion failure of microcirculation due to free radicals, interleukin and Endothelin-1. Twenty-one patients with tissue injury of the lower leg were included in our study, fourteen underwent a latissimus dorsi muscle transplantation with a combined ischaemia, seven patients had a tourniquet ischaemia for tumour resection, debridement and local flap transfer. The duration of ischaemia varied due to the course of operation. The withdrawal of venous blood via central vein catheter, flap vein and wound bed followed a fixed time table pre- and post-reperfusion (T1: preoperative day via cubital vein, T2: 6th postoperative day, T3: 5 min, T4: 10 min, T5: 15 min, T6: 1 h post-declamping and after tourniquet ischaemia via central vein catheter and T7: within 5 min from the flap vein immediate after recharging the flap). The vessel anastomosis determined the withdrawal from the local wound bed. ET-1 in venous blood samples were measured with ELISA. The duration of ischaemia in the tourniquet group ranged from 22 min up to 210 min with a mean of 76.58 min and in the latissimus group from 87 min up to 203 min with a mean of 139.21 min. The mean ET-1 plasma concentration measured systemically before operation in the 21 patients was 0.51 +/- 0.08 pg/ml (Mean +/- SD). This result corresponds with data published in literature. The locally measured plasma levels of ET-1 after tourniquet and flap ischaemia were increased with 0.34 up to 3.90 pg/ml (0.95 +/- 0.79 pg/ml [Mean +/- SD]) for the tourniquet group and with 0.34 up to 14.87 pg/ml (1.85 +/- 3.64 pg/ml [Mean +/- SD]) for the latissimus group. This is an increase compared to systemically measured values as 0.75 +/- 0.06 pg/ml (Mean +/- SD) for the tourniquet group and 0.58 +/- 0.21 pg/ml (Mean +/- SD) for the latissimus group. We conclude that Endothelin-1 is increased locally in the early reperfusion period after free latissimus dorsi-transplantation.