The Value of Negative-Pressure Wound Therapy and Flap Surgery in Hidradenitis Suppurativa - A Single Center Analysis of Different Treatment Options.

Background: Hidradenitis suppurativa is manifested by painful abscesses and scarring of sweat glands. Axillary, inguinal and genital regions are mostly affected. Multiple options exist in the treatment of hidradenitis suppurativa. The aim of this retrospective, mono-center cohort study was to analyze the outcome of different treatment methods after radical excision of hidradenitis suppurativa. Methods: We retrospectively evaluated the treatment strategy and recurrence rate of hidradenitis suppurativa. We included all eligible patients of legal age between February 2003 and October 2021, with the diagnosis of Hidradenitis suppurativa and the necessity for surgical treatment. All patients with surgical treatment and direct wound closure by suture were excluded. Bacterial load and flora were analyzed for primary and secondary reconstruction in combination with negative-pressure wound therapy. Patient data were analyzed for recurrence rate and remission time according to different reconstructive techniques. Results: In 44 affected anatomical sites (n = 23 patients) we treated 15 patients with negative-pressure wound therapy. Bacterial load and flora were lower in the last wound swab of patients with multi-surgical procedures (22 localizations) compared to the first wound swab independent of the use of negative-pressure wound therapy.Wound closure, independent of a direct and multi-stage procedure was achieved by local fasciocutaneous flaps (n = 12), secondary intention healing (n = 7), secondary intention healing with buried chip skin grafts (n = 10), or split-thickness skin grafts (n = 15). Radical excision combined with split-thickness skin grafts showed the lowest recurrence rate in the follow-up (16%; n = 4). Conclusion: Radical excision of hidradenitis suppurativa as gold standard for surgical treatment combined with negative-pressure wound therapy as multi-stage procedures ultimately reduced bacterial load and flora in our study. The use of split-thickness skin grafts showed the lowest recurrence rate.

Leaving the perfusion zones? Individualized flap design in 100 free DIEP and ms-TRAM flaps for autologous breast reconstruction using indocyanine green angiography.

BACKGROUND: There is still no consensus regarding the ideal zoning in abdominal-based autologous breast reconstruction using free DIEP or ms-TRAM flaps. In particular, the perfusion pattern of the flap according to the number of perforators used and their location remains controversial. In this study, the perfusion of free DIEP and ms-TRAM flaps is assessed intraoperatively and analyzed with regard to different perfusion patterns. METHODS: A retrospective analysis of 100 free flaps for breast reconstruction was performed. Following complete flap harvest, we used indocyanine green angiography for perfusion analysis. By applying two different contour levels, DIEP flaps with lateral or medial perforators and ms-TRAM flaps were assessed for their respective perfusion patterns. RESULTS: No statistically significant differences were found in the size of the perfusion area between the different flap types when applying the contour level of 20% (p >0.05). For the contour level of 30%, however, statistically significant differences were found between DIEP flaps with medially or laterally located perforators (p = 0.038). Laterally or medially located perforators in DIEP flaps showed no significant differences in their ability to cross the midline (contour level 20%, p = 0.068; contour level 30%, p = 0.058). CONCLUSION: Considering the variability of the perfusion of the abdominal wall and the high sensitivity of indocyanine green angiography for their detection, the abdominal zonings play a minor role. By using intraoperative indocyanine green angiography, a precise and patient-specific free flap surgery for autologous breast reconstruction is possible independent of perforator location.

[Establishing and evaluating a multinational Science Academy: A new tool for fostering scientific young talents in microsurgical research - a Consensus Statement of the DAM]. / Etablierung und Evaluation einer multinationalen Wissenschaftsakademie: Ein neues Modell zur Stärkung des wissenschaftlichen Nachwuchses in der mikrochirurgischen Forschung ­ Ein Konsensus Papier der DAM.

BACKGROUND: The formation of professional networks and cooperations - in addition to any qualified good education - seems fundamental for a successful career. In a number of disciplines, various symposia or conferences exist. In the field of microsurgery, however, a specific, guided and designated opportunity for junior scientists to network with one another has been missing so far. METHODS: In 2017, a science academy was initiated for the first time by the German-speaking Association for Nerves and Vessels (DAM) with the goal of bringing together and networking microsurgically researching young physicians and scientists. This was intended to happen on a small scale once a year in order to develop synergies for joint research projects. For this purpose, motivated junior researchers were individually selected by their mentors and sent to the academy by the boards of research institutions that are organized in the DAM. After getting to know each other in a relaxed atmosphere, the participants were given the opportunity to present their respective research project within the framework of thematic blocks and moderated by experienced mentors. Each presentation was followed by a round table discussion and small group work, in which knowledge and methods were exchanged and points of contact for possible later cooperation were identified. RESULTS: In the past 3 years, the DAM Science Academy proved to be an optimal format to initiate and promote networks of young researchers comprising microsurgically interested physicians and scientists. There were many lively and in-depth discussions, which were mainly due to the open working atmosphere and the obligation to confidentiality. Most of the synergies were shown i. a. in the field of angiogenesis, bioreactor, carcinoma-ADSC interactions, stem cells, AV loop model, ischemia/reperfusion, and nerve regeneration. The participants consistently gave a very positive feedback in the final evaluation with the wish to continue this academy. CONCLUSION: The DAM Science Academy can be considered a highly suitable complemental platform to the existing networking opportunities among microsurgical researchers. Experience so far suggests that this will hopefully result in long-term cooperations and a permanent transfer of knowledge among the participants.

Secondary breast reconstruction after mastectomy using the DIEP flap.

INTRODUCTION: Breast reconstruction is an important element in the successful therapy of breast cancer [1]. Thereby, autologous microvascular breast reconstruction has been shown to be a reliable technique. The use of a deep inferior epigastric perforator (DIEP) flap or a muscle-sparing (MS) free transverse rectus abdominis musculocutaneous (TRAM) flap is recognized in many centres as gold standard for reconstructive options [2-4]. Based on our experiences with 137 patients over a 5-year period we want to highlight the technical aspects of the free microsurgical autologous breast reconstruction using a DIEP flap. PATIENTS AND METHODS: Between 01/2013 and 12/2017 we treated 137 patients (age 32-78 years, mean age 52 years) after mastectomy with autologous microsurgical free flap breast reconstruction. A DIEP flap was used for breast reconstruction in 33 patients. In 104 cases, we performed a muscle sparing TRAM flap. In this video we demonstrate the typical sequence of operative steps of a DIEP flap in a 32 year old patient after mastectomy due to an invasive ductal breast carcinoma. RESULTS: The rate of total flap loss in our department was 2.2% including all patients. In less than 1%, partial flap necrosis could be observed. 61% of the patients had undergone previous irradiation. Within the small number of flap loss, we could not observe a trend towards a correlation between flap loss and previous irradiation. CONCLUSION: Autologous breast reconstruction using a DIEP or MS-TRAM flap provides a surgically safe technique including a low incidence of flap loss in specialized centres.

Force distribution of a cylindrical grip differs between dominant and nondominant hand in healthy subjects.

INTRODUCTION: Grip strength and load distribution of the hand are important parameters for evaluating hand function. The purpose of this study was to analyze and compare grip force and load distribution of dominant and nondominant hands in right-handed healthy subjects. METHODS: Gripping measurements were performed on 40 healthy right-handed subjects using a cylindrical gripping device. Two different cylinders with circumferences of 150 mm (small cylinder) and 200 mm (large cylinder), respectively, were used for the measurements. Subjects were assigned to either the small or the large cylinder with respect to their hand size. Maximum and mean force applied during three intervals of gripping as well as the percent contribution of each digit, thenar, and hypothenar in relation to the total load applied were acquired. Values of dominant and nondominant hands were compared. RESULTS: Percent contribution of mean grip strength differed for the thumb (p = 0.007), ring finger (p < 0.001), little finger (p = 0.047), and palm (p < 0.001). Comparing the dominant and nondominant side, the dominant hand showed a lower contribution of the thumb, ring finger, and little finger, but a higher contribution of the palm. When analyzing maximum grip, percent contribution of the small fingers was equal between dominant and nondominant side (p = 0.1). Differences between dominant and nondominant thumb, ring finger, and palm persisted (p = 0.007, p = 0.001, p = 0.005, respectively). No differences could be shown for the index finger, middle finger, thenar, and hypothenar when analyzing both mean and maximum force. DISCUSSION AND CONCLUSION: Percent contribution of the thumb and the fingers to total grip strength differed between dominant and nondominant hands with a change in distribution when assessing maximum grip force. In right-handed subjects, thumb and ring finger have important roles during gripping.

Mesenchymal stem cells and myoblast differentiation under HGF and IGF-1 stimulation for 3D skeletal muscle tissue engineering.

BACKGROUND: Volumetric muscle loss caused by trauma or after tumour surgery exceeds the natural regeneration capacity of skeletal muscle. Hence, the future goal of tissue engineering (TE) is the replacement and repair of lost muscle tissue by newly generating skeletal muscle combining different cell sources, such as myoblasts and mesenchymal stem cells (MSCs), within a three-dimensional matrix. Latest research showed that seeding skeletal muscle cells on aligned constructs enhance the formation of myotubes as well as cell alignment and may provide a further step towards the clinical application of engineered skeletal muscle. In this study the myogenic differentiation potential of MSCs upon co-cultivation with myoblasts and under stimulation with hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1) was evaluated. We further analysed the behaviour of MSC-myoblast co-cultures in different 3D matrices. RESULTS: Primary rat myoblasts and rat MSCs were mono- and co-cultivated for 2, 7 or 14 days. The effect of different concentrations of HGF and IGF-1 alone, as well as in combination, on myogenic differentiation was analysed using microscopy, multicolour flow cytometry and real-time PCR. Furthermore, the influence of different three-dimensional culture models, such as fibrin, fibrin-collagen-I gels and parallel aligned electrospun poly-ε-caprolacton collagen-I nanofibers, on myogenic differentiation was analysed. MSCs could be successfully differentiated into the myogenic lineage both in mono- and in co-cultures independent of HGF and IGF-1 stimulation by expressing desmin, myocyte enhancer factor 2, myosin heavy chain 2 and alpha-sarcomeric actinin. An increased expression of different myogenic key markers could be observed under HGF and IGF-1 stimulation. Even though, stimulation with HGF/IGF-1 does not seem essential for sufficient myogenic differentiation. Three-dimensional cultivation in fibrin-collagen-I gels induced higher levels of myogenic differentiation compared with two-dimensional experiments. Cultivation on poly-ε-caprolacton-collagen-I nanofibers induced parallel alignment of cells and positive expression of desmin. CONCLUSIONS: In this study, we were able to myogenically differentiate MSC upon mono- and co-cultivation with myoblasts. The addition of HGF/IGF-1 might not be essential for achieving successful myogenic differentiation. Furthermore, with the development of a biocompatible nanofiber scaffold we established the basis for further experiments aiming at the generation of functional muscle tissue.

[Surgical treatment of burns : Special aspects of pediatric burns]. / Chirurgische Behandlung von Verbrennungen : Besonderheiten bei Kindern.

BACKGROUND: Treatment of pediatric burn patients is very important because of the sheer frequency of burn wounds and the possible long-term ramifications. Extensive burns need special care and are treated in specialized burn centers. OBJECTIVES: The goal of this work is to present current standards in burn therapy and important innovations in the treatment of burns in children so that the common and small area burn wounds and scalds in pediatric patients in day-to-day dermatological practice can be adequately treated. MATERIALS AND METHODS: Analysis of current literature, discussion of reviews, incorporation of current guidelines. RESULTS: Burns in pediatric patients are common. Improvement of survival can be achieved by treatment in burn centers. The assessment of burn depth and area is an important factor for proper treatment. We give an overview for outpatient treatment of partial thickness burns. New methods may result in better long-term outcome. CONCLUSIONS: Adequate treatment of burn injuries considering current literature and guidelines improves patient outcome. Rational implementation of new methods is recommended.

Scalp reconstruction: A 10-year retrospective study.

Scalp reconstruction is a challenging task for the reconstructive surgeon. In consideration of the anatomical and cosmetic characteristics, the defect depth and size, an armamentarium of reconstructive procedures ranging from skin grafts over local flaps to free tissue transfer has been described. In this 10-year retrospective study, 85 operative procedures for scalp reconstruction were performed at our department. The underlying entity, defect size/depth, reconstructive procedure, complications, and mean hospital stay were analyzed. In most cases, scalp reconstruction was necessary after oncologic resection (67%) or radiation therapy (16%). A total of 85 operative procedures were performed for scalp reconstruction including local flaps (n = 50), free tissue transfer (n = 18), and skin grafts (n = 17). Regarding the complication rate, we could detect an overall major complication rate of 16.5% with one free flap loss. Briefly, local flaps are an adequate and safe procedure for limited scalp defects. In the case of extensive scalp defects affecting the calvarium, prior multiple surgical interventions and/or radiation, we prefer free tissue transfer.

[Sternal osteomyelitis - Surgical treatment concepts]. / Sternumosteomyelitis - chirurgische Behandlungskonzepte.

Sternal osteomyelitis is a potentially fatal condition following cardiac surgery. Sternal osteomyelitis should be diagnosed as early as possible followed by an interdisciplinary radical debridement. Subsequently plastic reconstructive surgery is necessary for defect reconstruction. This can be achieved by a number of established pedicled and free flap plastic surgery procedures. The choice of flap procedures is based on defect geometry and the individual patient situation, including potential flap donor sites. Smaller defects can generally be reconstructed by pedicled flap transfer. For extensive sternal defects, free flap transplantation is now a well-established therapeutic option. In some patients lacking sufficient recipient vessels, the creation of an arteriovenous (AV) loop as recipient vessel is necessary. In summary, successful therapy of sternal osteomyelitis is based on early interdisciplinary treatment by the various surgical subspecialties.

[Merkel Cell Carcinoma - A Rare Entity with Specific Reconstructive Challenges]. / Merkelzellkarzinome - eine seltene Entität mit spezifischen rekonstruktiven Herausforderungen.

BACKGROUND: Merkel cell carcinoma is a rare tumor, which is associated with poor prognosis. It has been shown that radical local excision and radiotherapy are essentiell for curative therapy. To avoid compromise in tumor treatment, plastic surgery is often needed. Furthermore, using complex reconstruction methods, like free flap transplantation, has proven to be effective to avoid long and complicated clinical courses. PATIENTS: Between 2003 and 2016 15 patients with Merkel cell carcinoma were treated in our department. In 2 cases additional resection had to take place before reconstruction was performed. In most cases, a safety margin of 2 cm was chosen. Complete excision could be achieved in 13 patients. We used different methods of reconstruction such as primary suturing, skin transplantations, local, pedicled or free flaps. RESULTS: In all patients defects could be reconstructed with good results, which proved to be stable even under postoperative radiation therapy. CONCLUSION: Given the modern techniques of plastic surgery the extent of local excision should not be should be chosen as radical as possible and necessary. It has been proven that interdisciplinary treatment of patients with Merkel cell carcinoma increases the chances for curative therapy while providing safe methods for reconstruction despite radiotherapy, extensive tumors or difficult localization.

[Establishment and Evaluation of a Microsurgery Course for Medical Students]. / Etablierung und Evaluation eines Mikrochirurgie - Kurses für Medizinstudierende.

BACKGROUND: Very few microsurgical courses have been offered for medical students in Germany to date. To raise early interest in this technique, which is essential for plastic and reconstructive surgery, and to guide eligible medical students to choose plastic surgery as their specialist field, the Department of Plastic and Hand Surgery, supported by the Faculty of Medicine of the Friedrich-Alexander-University of Erlangen-Nuremberg, implemented a microsurgical course for students in 2011. This study describes the implementation of that course and evaluates its impact on the subsequent choice of the participants' specialist fields. MATERIAL AND METHODS: Since the summer of 2011, the microsurgery course for medical students has taken place regularly 3 times per term. It is free of charge for participants and is guided by senior physicians of the Department of Plastic and Hand Surgery together with student tutors from the Faculty of Medicine. The arterial end-to-end anastomosis in the fresh chicken leg is used as a training model. Based on a questionnaire survey the participants were evaluated and statistically analysed regarding their course satisfaction, self-assessment of their own eligibility before and after the course, the anticipated future choice of their medical specialist field and how their choice was influenced by this course. RESULTS: After the successful implementation of the microsurgical course in 2011, a significant number of students were interested in microsurgery. According to the questionnaire, the level of enthusiasm was high among all participants. The self-assessment of microsurgical skills improved significantly after the course compared with the pre-course assessment. In 82% of the participants, the course had a strong positive influence on the future choice of their specialist field. CONCLUSIONS: The regular implementation of a microsurgical course for students in the form described here is practicable and possible without undue personnel and cost of materials. The ongoing interest among students in such an offer is enormous and the satisfaction of the participants is very high. This might be a way to recruit future plastic surgeons by raising early enthusiasm for microsurgery. These future plastic surgeons, in turn, would be given the chance to experience a very fascinating aspect of plastic surgery, which might help them to decide on their specialisation within that field at a later point in their career.

Automatic quantification of angiogenesis in 2D sections: a precise and timesaving approach.

INTRODUCTION: The standardized characterization of angiogenesis is crucial in the field of tissue engineering as sufficient blood supply is the limiting factor of mass transfer. However, reliable algorithms that provide a straight forward and observer-independent assessment of new vessel formation are still lacking. We propose an automatic observer-independent quantitative method (including downloadable source code) to analyze vascularization using two-dimensional microscopic images of histological cross-sections and advanced postprocessing, based on a 'positive- and negative-experts' model and a (corrected) nearest neighbour classification, in a vascularized tissue engineering model. MATERIALS AND METHODS: An established angioinductive rat arteriovenous loop model was used to compare the new automatic analysis with a common 2D method and a µCT algorithm. Angiogenesis was observed at three different time points (5, 10 and 15 days). RESULTS: In line with previous results, formation of functional new vessels that arose from the venous graft was evident within the three-dimensional construct and a significant (p < 0.05) increase in vessel count and area was observed over time. The proposed automatic analysis obtained precise values for vessel count and vessel area that were similar to the manually gained data. The algorithm further provided vectorized parameterization of the newly formed vessels for advanced statistical analysis. Compared to the µCT-based three-dimensional analyses, the presented two-dimensional algorithm was superior in terms of small vessel detection as well as cost and time efficiency. CONCLUSIONS: The quantitative evaluation method, using microscopic images of stained histological sections, 'positive- and negative-experts'-based vessel segmentation, and nearest neighbour classification, provides a user-independent and precise but also time- and cost-effective tool for the analysis of vascularized constructs. Our algorithm, which is freely available to the public, outperforms previous approaches especially in terms of unambiguous vessel classification and statistical analyses.

[Avoidance of complications in oncological surgery of the pelvic region : combined oncosurgical and plastic reconstruction measures]. / Komplikationsvermeidung in der onkologischen Chirurgie der Becken-/Leistenregion : Kombiniert onkochirurgische und plastisch-rekonstruktive Maßnahmen.

Prevention of perioperative and postoperative complications resulting from surgical oncology in the pelvic region remains a major interdisciplinary challenge. With modern interdisciplinary concepts joining forces of various surgical specialties, tumor resection can be sufficiently carried out with wide margins and the patients benefit from reduced morbidity even in complex situations. As an example chronic fistulation and secretion from the presacral cavity and sinus may result as potential sequelae from intra-abdominal and intrapelvic tumor resection, especially when neoadjuvant multimodal therapies have been applied. This can be prevented by simultaneous transplantation of for example transpelvic vertical rectus abdominis myocutaneous (VRAM) flap transfer, while extensive perineal skin and soft tissue defects may also be simultaneously reconstructed. In cases of malignant soft tissue tumors in the pelvic region a staged surgical procedure can be performed with a period of time between tumor resection and reconstruction. Thus, a histological R0 status can be secured prior to plastic reconstruction surgery in order to increase oncological safety. In cases of postresectional exposition of e. g. pelvic or femoral vessels or intrapelvic and intra-abdominal organs simultaneous flap procedure is mandatory.The reconstructive armamentarium of the plastic surgeon should contain not only pedicled but also free microsurgical flaps so that no compromise in terms of the extent of the oncological resection has to be accepted. At the same time perioperative and postoperative complications may be avoided and the patient quality of life can be preserved even in more complex cases.

Nutrient free flaps with vascular bypasses for extremity salvage in patients with chronic limb ischemia.

AIM: Treatment of severe wounds remains a surgical challenge in patients with critical limb ischemia (CLI). In some patients with end stage disease a combined arterial and venous vascular bypass together with immediate or subsequent free soft tissue transfer can become necessary to salvage the limb. The aim of this paper was to develop an algorithm of differential approaches of interdisciplinary reconstructions with bypasses and free flaps for leg salvage. METHODS: From our experiences with over 76 patients receiving a vascular bypass and a free microsurgical tissue transfer, we analyzed the various configurations of possible vascular constellations and treatment options. We derived an algorithm for the combined interdisciplinary surgical approach. RESULTS: We found the surgical technique to be one of the main predictors for the final outcome and categorized the various options and vascular configurations in combination with free flaps to salvage extremities. The overall complication rate with more than 20% revisional surgeries is higher than in routine free flap transfer for reconstructions in patient without CLI. We observed 3 failures (4%) with complete flap loss and bypass occlusion and found 3 patients (4%) with initially successful reconstructions to have secondary amputations within 6 to 18 months postoperatively. CONCLUSION: Given the multitude of concomitant diseases in patients with serious wounds and CLI the distinct choice of the individual reconstructive vascular/flap-procedure has to be thoroughly selected. Any treatment decision against revascularization must be made only with proper and adequate diagnosis based on proper and sufficient diagnostic imaging techniques following an interdisciplinary discussion of possible options for limb salvage. Based on our experience with a large series of this type of combined revascularization-flap reconstruction we developed a specific algorithm of surgical variants of bypass-free flap arterial and venous reconstructions that is presented in this paper.

A hundred patients with vertical rectus abdominis myocutaneous (VRAM) flap for pelvic reconstruction after total pelvic exenteration.

PURPOSE: We analysed the outcomes of a series of 100 consecutive patients with anorectal cancer with neoadjuvant radiochemotherapy and abdominoperineal exstirpation or total pelvic exenteration, who received a transpelvic vertical rectus abdominis myocutaneous (VRAM) flap for pelvic, vaginal and/or perineal reconstruction and compare a cohort to patients without VRAM flaps. METHODS: Within a 10-year period (2003-2013) in our institution 924 patients with rectal cancer stage y0 to y IV were surgically treated. Data of those 100 consecutive patients who received a transpelvic VRAM flap were collected and compared to patients without flaps. RESULTS: In 100 consecutive patients with transpelvic VRAM flaps, major donor site complications occurred in 6 %, VRAM-specific perineal wound complications were observed in 11 % of the patients and overall 30-day mortality was 2 %. CONCLUSIONS: The VRAM flap is a reliable and safe method for pelvic reconstruction in patients with advanced disease requiring pelvic exenteration and irradiation, with a relatively low rate of donor and recipient site complications. In this first study, to compare a large number of patients with VRAM flap reconstruction to patients without pelvic VRAM flap reconstruction, a clear advantage of simultaneous pelvic reconstruction is demonstrated.

Induction of bone formation in biphasic calcium phosphate scaffolds by bone morphogenetic protein-2 and primary osteoblasts.

Bone tissue engineering strategies mainly depend on porous scaffold materials. In this study, novel biphasic calcium phosphate (BCP) matrices were generated by 3D-printing. High porosity was achieved by starch consolidation. This study aimed to characterise the porous BCP-scaffold properties and interactions of osteogenic cells and growth factors under in vivo conditions. Five differently treated constructs were implanted subcutaneously in syngeneic rats: plain BCP constructs (group A), constructs pre-treated with BMP-2 (group B; 1.6 µg BMP-2 per scaffold), seeded with primary osteoblasts (OB) (group C), seeded with OB and BMP-2 (group D) and constructs seeded with OB and pre-cultivated in a flow bioreactor for 6 weeks (group E). After 2, 4 and 6 weeks, specimens were explanted and subjected to histological and molecular biological analyses. Explanted scaffolds were invaded by fibrovascular tissue without significant foreign body reactions. Morphometric analysis demonstrated significantly increased bone formation in samples from group D (OB + BMP-2) compared to all other groups. Samples from groups B-E displayed significant mRNA expression of bone-specific genes after 6 weeks. Pre-cultivation in the flow bioreactor (group E) induced bone formation comparable with group B. In this study, differences in bone distribution between samples with BMP-2 or osteoblasts could be observed. In conclusion, combination of osteoblasts and BMP-2 synergistically enhanced bone formation in novel ceramic scaffolds. These results provide the basis for further experiments in orthotopic defect models with a focus on future applications in orthopaedic and reconstructive surgery.

[Extended skin and soft tissue defects after vascular wounds: plastic surgical concepts]. / Ausgedehnte Gewebedefekte bei vaskulären Wunden--Möglichkeiten der plastischen Chirurgie.

INTRODUCTION: Skin and soft-tissue defects at the ischaemic lower extremity represent a challenging condition. Major amputations can be prevented by optimised surgical therapy. The aim of any intervention is the revascularisation and defect reconstruction of the extremity. METHODS: This article aims to provide a structured overview on up-to-date therapeutic strategies and differentiated indications for certain surgical flaps in combination with bypass surgery for the treatment of chronic "vascular" wounds. RESULTS: Optimised conservative wound therapy, skin grafts, pedicled or microsurgical free flaps in combination with vascular bypasses can be applied to salvage ischaemic extremities. These operations require an interdisciplinary cooperation between vascular surgeons and plastic surgeons. DISCUSSION: These procedures should accordingly only be performed in specialised high-volume centres with significant vascular surgical and microsurgical expertise.

[Peroneal artery perforator flap]. / Gefässgestielte Arteria-peronea-Perforatorlappenplastik.

OBJECTIVE: Defect reconstruction at the distal lower extremity by transposition of a vascularised fasciocutaneous flap. INDICATIONS: Reconstruction of defects at the lateral aspect of the middle and distal third of the lower leg, the lateral ankle and achilles tendon region. CONTRAINDICATIONS: Lesions or occlusion of the peroneal artery, traumatized skin and soft tissues at the donor site of the flap, deep vein thrombosis of the ipsilateral leg. SURGICAL TECHNIQUE: Preoperative localisation of the dominant perforator using Duplex or Doppler ultrasound or CT-angiography. Initially limited skin incision and identification and microsurgical dissection of the dominant perforator up to its origin from the peroneal artery. Completion of skin incision and mobilisation of the flap while the secondary perforans vessels are still preserved. Evaluation of flap perfusion and transfer of the flap into the defect by advancement or 180° rotation as a propeller flap. Closure of the donor site defect by direct suture or skin grafts. POSTOPERATIVE MANAGEMENT: Elevation of the extremity for 5 days. Elastocompressive garments and orthostatic training with increasing intensity. Standardised postoperative compression therapy and scar therapy if necessary. RESULTS: Minimal functional donor site defect and optimal functional and aesthetic results.

Axially vascularized bone substitutes: a systematic review of literature and presentation of a novel model.

INTRODUCTION: The creation of axially vascularized bone substitutes (AVBS) has been successfully demonstrated in several animal models. One prototypical indication is bone replacement in patients with previously irradiated defect sites, such as in the mandibular region. The downside of current clinical practice, when free fibular or scapular grafts are used, is the creation of significant donor site morbidity. METHODS: Based on our previous experiments, we extended the creation of an arterio-venous loop to generate vascularized bone substitutes to a new defect model in the goat mandibula. In this report, we review the literature regarding different models for axially vascularized bone substitutes and present a novel model demonstrating the feasibility of combining this model with synthetic porous scaffold materials and biological tissue adhesives to grow cells and tissue. RESULTS: We were able to show the principal possibility to generate axially vascularized bony substitutes in vivo in goat mandibular defects harnessing the regenerative capacity of the living organism and completely avoiding donor site morbidity. CONCLUSION: From our findings, we conclude that this novel model may well offer new perspectives for orthopedic and traumatic bone defects that might benefit from the reduction of donor site morbidity.