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Background Extremity replantation as well as allotransplantation aim to restore form and function of the amputated limb. Both approaches, however, are clearly limited by the ischemic time. Ex vivo perfusion (EVP), already well-established in the field of solid organ transplantation, represents a promising tool to overcome this restriction. Methods We have currently established the technical requirements to provide EVP to severed limbs in a clinical hospital setting and hereby report of a 48-hour hypothermic EVP (EVP48) of an upper extremity amputated at the level of the proximal humerus, followed by a 2-hour simulated reperfusion (2SR) with donor blood. Results Muscle biopsies revealed histopathologically well preserved, vital muscle tissue after EVP24, and partially grouped muscle fiber necrosis with predominantly vital muscle tissue after EVP48 and 2SR. Analyses of perfusate samples showed a marked decline of biochemical muscle damage markers during EVP48. Cytokine analysis disclosed an isolated increase of the proinflammatory cytokines, interleukine-6, monocyte chemotactic protein-1, and interferon-γ, during EVP and 2SR. Magnetic resonance imaging, performed after EVP48, indicated partial muscle necrosis of the intrinsic hand muscles only, while no signs for infection or inflammation were present. Conclusion Our single case experience shows the general feasibility of an amputated limb ex vivo salvage perfusion setting to allow for delayed replantation up to 24 hours. Nevertheless, an accurate prior planning is crucial to ensure successful implementation of EVP in the acute clinical setting.

Loss of skin grafts can be a dangerous complication during the early postoperative course of patients with extensive burns. A major risk factor for impaired healing of grafts is local wound infection due to bacterial colonization. Burn wounds are particularly prone to bacterial colonization. In this retrospective cohort study, we analyzed correlations between bacteria isolates from burn wounds and loss of skin grafts after surgical treatment. A cohort of patients with burn wounds who received split-skin grafts for wound coverage was divided into groups with and without loss of skin grafts. Demographics, comorbidities, trauma characteristics and bacterial isolates from wound cultures were reviewed and compared. Bacterial colonization isolated from burn wounds upon hospital admission was found to be a significant predictor of skin-graft loss. Additionally, an Abbreviated Burn Severity Index greater 6 predicted graft loss. When comparing bacterial swab results from admission with isolates from revision surgery after graft loss, causative pathogens were found to have changed.

Secondary infections of skin grafts pose a continuous problem in burn patients, very often leading to loss of transplanted skin grafts and making multiple surgical revisions necessary. We present a case report about persisting Pseudomonas aeruginosa infection in burn patients with known diabetes. The burn wounds in lower extremities required repeated debridements, multiple skin grafting attempts and finally an application of the dermal scaffold NovoSorb BTM. With these measures, we managed to undertake a successful reconstruction of infected burn defects and pre-vent an amputation. We concluded that the NovoSorb BTM could be seen as an additional promising tool in a burn surgery armamentarium. In cases where radical surgical wound decontamination is not possible without risking the loss of the limb, the application of NovoSorb BTM over a contaminated field can win extra time for topical infection treatment and additionally provide an excellent skin grafting ground.

Implementation of tubular endothelial cell networks is a prerequisite for 3D tissue engineering of constructs with clinically relevant size as nourishment of cells is challenged by the diffusion limit. In vitro generation of 3D networks is often achieved under conditions using serum containing cell culture medium and/or animal derived matrices. Here, 3D endothelial cell networks were generated by using human umbilical vein endothelial cells (HUVECs) in combination with human adipose tissue derived stromal cells (hASCs) employing human collagen I as hydrogel and decellularized porcine small intestinal submucosa as starter matrix. Matrigel/rat tail collagen I hydrogel was used as control. Resulting constructs were cultivated either in serum-free medium or in endothelial growth medium-2 serving as control. Endothelial cell networks were quantified, tested for lumen formation, and interaction of HUVECs and hASCs. Tube diameter was slightly larger in constructs containing human collagen I compared to Matrigel/rat tail collagen I constructs under serum-free conditions. All other network parameters were mostly similar. Thereby, the feasibility of generating 3D endothelial cell networks under serum-free culture conditions in human collagen I as hydrogel was demonstrated. In summary, the presented achievements pave the way for the generation of clinical applicable constructs.

Objectives Cutaneous ischemia/reperfusion (CI/R) injury has shown to play a significant role in chronic wounds such as decubitus ulcers, diabetic foot ulcers, atherosclerotic lesions, and venous stasis wounds. CI/R also plays a role in free tissue transfer in reconstructive microsurgery and has been linked to clinical burn-depth progression after thermal injury. While the role of the complement system has been elucidated in multiple organ systems, evidence is lacking with respect to its role in the skin. Therefore, we evaluated the role of the complement system in CI/R injury. Methods Using a single pedicle skin flap mouse model of acute CI/R, we performed CI/R in wild-type (WT) mice and complement knock out (KO) mice, deficient in either C1q (C1q KO; classical pathway inhibition), mannose-binding lectin (MBL null; lectin pathway inhibition) or factor B (H2Bf KO; alternative pathway inhibition). Following 10 h ischemia and 7 days reperfusion, mice were sacrificed, flaps harvested and flap viability assessed via Image J software. The flap necrotic area was expressed as % total flap area. In another group, mice were sacrificed following CI/R with 10 h ischemia and 48 h reperfusion. Two cranial skin flap samples were taken for gene expression analysis of IL1b, IL6, TNFα, ICAM1, VCAM1, IL10, IL13 using real-time polymerase chain reaction (RT-PCR). Results Following CI/R, MBL null mice had a statistically significant smaller %necrotic flap area compared to WT mice (10.6 vs. 43.1%; p Conclusions We demonstrated for the first time a significant role of MBL and the lectin complement pathway in ischemia/reperfusion injury of the skin and a potential role for IL10 in attenuating CI/R injury, as IL10 levels were significantly increased in the tissue from the CI/R-protected MBL null group.

The profitability of medical treatment has gained increasing importance in health politics and likewise has become a considerable part of a microsurgeon's daily practice. The resulting cost pressure leads to microsurgeons having to justify their often complex and expensive treatments against hospital providers and health insurances. In this position paper of the German Speaking Group for Microsurgery of Peripheral Nerves and Vessels, we analyze the current status of profitability of microsurgical extremity and breast reconstruction, and its impact on choice of therapy and residency training. We specifically highlight the available literature, that shows often reduced long-term treatment costs after microsurgical reconstruction in comparison to cheaper initial treatments. The statements are based on a consensus workshop on the 40th meeting of the DAM in Lugano, Switzerland.Die Wirtschaftlichkeit von Therapien hat im Gesundheitswesen zunehmenden Stellenwert erlangt und wird dadurch auch für Mikrochirurgen ein relevanterer Aspekt ihrer Arbeit. Vor allem der verbundene Kostendruck, langfristig wirtschaftlich zu agieren, nötigt Mikrochirurgen ihre oftmals komplexen Behandlungen gegenüber Krankenversicherungen und Krankenhausträgern zu rechtfertigen. In diesem Positionspaper der deutschsprachigen Arbeitsgemeinschaft für Mikrochirurgie (DAM) wird der derzeitige Status Quo der Wirtschaftlichkeit in der mikrochirurgischen Extremitäten- und Brustrekonstruktion analysiert, sowie auch die daraus resultierenden Konsequenzen auf Therapiewahl und Weiterbildung. Ebenfalls wurde eine Analyse der Literatur gelegt, welche oftmals gesenkte Folgekosten nach komplexen Rekonstruktionen im Vergleich zu chirurgisch günstigeren Alternativverfahren beschreibt. Die beschriebenen Inhalte wurden auf einem Konsensusworkshop anlässlich der 40. Jahrestagung der DAM 2018 in Lugano erarbeitet.

Needlestick injuries (NSI) are potentially infectious injuries from sharp or pointed medical instruments and through contact with blood on mucous membranes or nonintact skin. Although the European Union (EU) Council directive 2010/32/EU on the prevention of NSI was implemented in EU countries in 2013, information on the effectiveness of the measures is limited.The aim of this study was to evaluate the effectiveness of a safety concept according to the EU Council Directive 2010/32/EU on prevention of NSI.In 2016 the NSI safety concept at a large regional hospital was improved according to 2010/32/EU, specifically by an update of blood screening profiles and standard operating procedures (SOP), better dissemination of information to employees and complete conversion to safety cannulas and scalpels. The medical records of all NSIs from 2015-2017 were retrospectively anonymized and evaluated and a cost analysis was performed.The number of NSIs in 2017 was significantly reduced by 48.4% as compared to 2016 and NSIs with scalpels were completely prevented. The proportion of employees with NSIs who were adequately immunized against hepatitis B was significantly increased to 84.1% in 2017. Furthermore, identification of the index patient was significantly increased to 82.5% in 2017. The cost of avoiding NSIs increased by a total of 24.1% in 2017 as compared to 2015 before introduction of the safety concept.Implementation of the EU Council directive 2010/32/EU, resulted in an almost 50% reduction in NSIs over 1 year, including the complete prevention of NSIs due to scalpels. In addition, the anamnestic presence of immunization against hepatitis B and index patient identification were significantly increased.

Soft-tissue defect closure of the volar and dorsal aspect of the hand and lower arm with a maximum defect size of 10 × 25 cm.Soft-tissue defects of the entire palm and dorsum of the hand and lower arm with a maximum defect size of 10 × 25 cm.Polytraumatized patients presenting with concomitant life-threatening injuries. In these cases one should perform the definite defect closure secondary after cardiovascular stabilization. Scars and vascular injury at the donor site. Lack of vascularity and necrosis of implantation site. Poorly vascularized recipient site (e.g. after radiation) Infection and necrosis at the donor and/or recipient site. Prior operations of the groin with impairment of the vasculature. Noncompliant patient.Landmarks are the femoral artery, inguinal ligament, anterior superior iliac spine, and sartorius muscle. The superior and inferior border of the flap should be orientated parallel to the inguinal ligament. The longitudinal axis of the flap is parallel to the superficial circumflex iliac artery, which is partially located superior to the inguinal ligament. One third of the flap is located superior, and two thirds inferior, to the inguinal ligament. Flap dissection starts at the lateral border without including the fascia. Identification of the lateral border of the sartorius muscle, incision of its fascia and inclusion of the fascia into flap dissection in order to preserve the vessel. If a long flap pedicle is favored, flap dissection is continued to the source of the superficial circumflex iliac artery. Primary closure of the donor site and, finally, inset of the flap. A tubed pedicle protects the vessels and simplifies the ischemic preconditioning during the postoperative phase. According to the flap size, the donor site closure is either primary or split-thickness skin grafting is necessary at the lateral aspect of the donor site. The mean duration of the procedure is 120 min in a teaching hospital (own data).The patient should be mobilized as early as possible. Dressings and flap monitoring should be performed daily. Ischemic preconditioning by applying a tourniquet starts after 10-14 days. The ischemic period is increased continuously from 3 × 5 min/d in the beginning to 3 × 1 h/d before flap dissection. Flap dissection of the pedicle is performed after 3 weeks. The residual donor site is closed, while the distal pedicle is left untrimmed and closed secondarily a few days later to allow for sufficient venous drainage. Finally, defect closure can be completed after demarcation of the pedicle.In a 3-year period, defect closure with a pedicled groin flap was performed in 14 patients. Indications for this procedure were the following: thumb reconstruction for lengthening and defect closure after amputation and burn injury, soft-tissue reconstruction of the dorsum of the hand after decollement and infection, soft-tissue reconstruction of the distal part of the lower arm, wrist and palm after complex and combined trauma, and plastic reconstructive preservation of multiple fingers with subsequent phalangealization and syndactyly release, respectively. In all patients, complete soft-tissue coverage and flap survival could be achieved. The functional and aesthetic result was satisfactory in all cases.