S. Kall

Use of spider silk fibres as an innovative material in a biocompatible artificial nerve conduit.

Defects of peripheral nerves still represent a challenge for surgical nerve reconstruction. Recent studies concentrated on replacement by artificial nerve conduits from different synthetic or biological materials. In our study, we describe for the first time the use of spider silk fibres as a new material in nerve tissue engineering. Schwann cells (SC) were cultivated on spider silk fibres. Cells adhered quickly on the fibres compared to polydioxanone monofilaments (PDS). SC survival and proliferation was normal in Live/Dead assays. The silk fibres were ensheathed completely with cells. We developed composite nerve grafts of acellularized veins, spider silk fibres and SC diluted in matrigel. These artificial nerve grafts could be cultivated in vitro for one week. Histological analysis showed that the cells were vital and formed distinct columns along the silk fibres. In conclusion, our results show that artificial nerve grafts can be constructed successfully from spider silk, acellularized veins and SC mixed with matrigel.

Lipomas after blunt soft tissue trauma: are they real? Analysis of 31 cases

Background  Soft tissue trauma and lipomas are common occurrences in surgical practice. Lipomas are defined as benign tumours of adipose tissue with so far unexplained pathogenesis and aetiology. A link between preceding blunt soft tissue trauma at the site of the tumour and the formation of lipomas has been described earlier. These soft tissue tumours have been named ‘post‐traumatic lipomas’.

Outcome of simultaneous and staged microvascular free tissue transfer connected to arteriovenous loops in areas lacking recipient vessels.

Background: Arteriovenous loops are an indispensable tool in free flap surgery when appropriate recipient vessels are missing. In this study, the authors analyzed whether the outcome differs when flaps were transferred simultaneously or subsequently after construction of arteriovenous loops. Methods: Twenty-seven patients requiring free tissue transfer received arteriovenous loops by pedicled or free vein grafts because of inadequate local recipient vessels. In head and neck reconstruction, pedicled brachiocephalic or free saphenous vein grafts were anastomosed to cervical or axillary vessels. Pedicled major saphenous vein grafts were used in the pelvic area whereas, in lower leg and foot reconstruction, free saphenous or brachiocephalic veins were used. Flaps were transferred simultaneously (n = 10) or 4 to 17 days later (n = 17). Results: Thrombosis required revision in staged transfer (n = 3 patients) or in simultaneous flap transfer (n = 2). No free flap was lost. Fisher’s exact test did not indicate a significant difference between a simultaneous or staged flap transfer. Conclusions: Temporary arteriovenous loops provide adequate recipient vessels and flow to supply microvascular free flap tissue transfer in areas lacking recipient vessels and in which no other reconstructive options exists. No statistical differences in complications and overall outcome were found between immediate or secondary free tissue transfer. Meticulous monitoring of microvascular perfusion, however, is mandatory in both approaches and early intervention is necessary to ensure successful tissue transfer.

Neurovaskuläre Lappen zur Rekonstruktion von Fingerendglieddefekten

ZusammenfassungDie Fingerkuppe ist ein hoch spezialisiertes Endorgan mit besonderer Ausbildung des Tastsinns. Wir möchten mit dieser Arbeit die verschiedenen Fingerkuppenrekonstruktionsverfahren vorstellen und eine Systematik der Differenzialindikation der unterschiedlichen Techniken erstellen. Diese Techniken beinhalten das gesamte Spektrum der Rekonstruktion mittels lokalen neurovaskulären Lappen (palmare VY-Dehnungslappenplastik nach Atasoy, Kutler-Lappen, palmare Dehnungslappenplastik nach Moberg, laterale Dehnungslappenplastik nach Venkataswami und Subramanian, palmare Translationslappenplastik nach Hueston) über Fernlappen (Littler-Lappen, Foucher-Lappen, dorsaler Metakarpalarterienlappen, Cross-Finger-Lappen, reversed Cross-Finger-Lappen) bis zu freien mikrochirurgischen Gewebetransfers (mikrochirurgische Zehenpulpatransplantation, Spare-Part-Transplantation). Die Vor- und Nachteile der jeweiligen Rekonstruktionstechnik werden diskutiert. Wir haben einen Algorithmus als Hilfsmittel zur Vereinfachung der korrekten Auswahl des jeweiligen Rekonstruktionsverfahrens entwickelt.AbstractThe fingertip is an extremely specialized end organ with a highly developed sense of touch. In this article, we present the different ways of reconstructing a traumatized fingertip. Additionally, we systematically explain the differential indications for the different techniques available. The whole spectrum of fingertip reconstruction is discussed, starting from local neurovascular flaps (palmar VY-Atasoy flap, Kutler flap, palmar Moberg flap, lateral Venkataswami and Subramanian flap, palmar Hueston flap), distant flaps (Littler flap, Foucher flap, dorsal metacarpal artery flap, cross-finger flap, reversed cross-finger flap) and finally free flap transfer (free toe-pulp transfer, spare-part transplantation). The advantages and disadvantages of each flap are highlighted. We develop an algorithm to facilitate finding the correct type of reconstruction.

Inhibition of apoptosis by expression of antiapoptotic proteins in recombinant human keratinocytes.

The Fas ligand/Fas interaction plays an important role in the regulation of immune responses. Allografted cells undergo Fas-mediated apoptosis induced by CD8+ T cells. Our objective was to prevent human keratinocytes from immunologically induced apoptosis. We focused on three proteins with inhibitory function on Fas-mediated apoptosis. Human keratinocytes were transfected with either Flip, Faim, or Lifeguard (LFG). The treatment proved to be practicable and efficient. The recombinant keratinocytes with expression of our target proteins were cocultured with CD8+ T cells and the apoptotic activity was then evaluated. Activation of caspase-8 was detectable in control but not in the recombinant cells. Quantitative analysis revealed significant induction of T-cell-induced apoptosis in nontransfected keratinocytes (p = 0.04, n = 12) but not in Flip (p = 0.66), Faim (p = 0.42), or LFG (p = 0.44) expressing cells. Our results suggest that heterotopic expression of antiapoptotic proteins can induce the resistance of keratinocytes to a major mechanism of rejection.

Neurovascular flaps for the reconstruction of fingertip injuries

ZusammenfassungDie Fingerkuppe ist ein hoch spezialisiertes Endorgan mit besonderer Ausbildung des Tastsinns. Wir möchten mit dieser Arbeit die verschiedenen Fingerkuppenrekonstruktionsverfahren vorstellen und eine Systematik der Differenzialindikation der unterschiedlichen Techniken erstellen. Diese Techniken beinhalten das gesamte Spektrum der Rekonstruktion mittels lokalen neurovaskulären Lappen (palmare VY-Dehnungslappenplastik nach Atasoy, Kutler-Lappen, palmare Dehnungslappenplastik nach Moberg, laterale Dehnungslappenplastik nach Venkataswami und Subramanian, palmare Translationslappenplastik nach Hueston) über Fernlappen (Littler-Lappen, Foucher-Lappen, dorsaler Metakarpalarterienlappen, Cross-Finger-Lappen, reversed Cross-Finger-Lappen) bis zu freien mikrochirurgischen Gewebetransfers (mikrochirurgische Zehenpulpatransplantation, Spare-Part-Transplantation). Die Vor- und Nachteile der jeweiligen Rekonstruktionstechnik werden diskutiert. Wir haben einen Algorithmus als Hilfsmittel zur Vereinfachung der korrekten Auswahl des jeweiligen Rekonstruktionsverfahrens entwickelt.AbstractThe fingertip is an extremely specialized end organ with a highly developed sense of touch. In this article, we present the different ways of reconstructing a traumatized fingertip. Additionally, we systematically explain the differential indications for the different techniques available. The whole spectrum of fingertip reconstruction is discussed, starting from local neurovascular flaps (palmar VY-Atasoy flap, Kutler flap, palmar Moberg flap, lateral Venkataswami and Subramanian flap, palmar Hueston flap), distant flaps (Littler flap, Foucher flap, dorsal metacarpal artery flap, cross-finger flap, reversed cross-finger flap) and finally free flap transfer (free toe-pulp transfer, spare-part transplantation). The advantages and disadvantages of each flap are highlighted. We develop an algorithm to facilitate finding the correct type of reconstruction.

Gefäßchirurgische Interventionen und plastisch-rekonstruktive Chirurgie

ZusammenfassungTrotz der hohen Prävalenz arterieller Verschlusskrankheiten existieren nur wenige Untersuchungen über den Effekt interventioneller Maßnahmen zur Rekanalisierung von Extremitätengefäßen vor plastisch-chirurgischen Eingriffen. Ziel der Untersuchung war es, die Übereinstimmung von einfachen klinischen Untersuchungstechniken mit apparativer Diagnostik zur Diagnose von arteriellen Perfusionsstörungen zu prüfen und die Ergebnisse der Defektdeckung nach gefäßchirurgischer Intervention zu bewerten.In dieser retrospektiven Studie wurden 150 Patienten mit chronischen Wunden der unteren Extremität mittels Palpation der Fußpulse, Dopplersonographie und Verschlussdruckmessung im Hinblick auf eine pAVK untersucht und pathologische Befunde angiographisch überprüft. Dem plastisch-chirurgischen Wundverschluss wurde dann eine gefäßchirurgische Intervention zur Verbesserung der Perfusion vorgeschaltet.Bei allen 34 Patienten mit fehlenden Fußpulsen oder pathologischen Verschlussdrücken wurde die klinische Diagnose der peripheren arteriellen Verschlusskrankheit durch eine angiographische Gefäßdarstellung bestätigt. Es konnte stets postinterventionell eine Rekanalisierung der versorgenden Gefäße des Wundgebietes erzielt und anschließend ein Defektverschluss erreicht werden.Mittels einfacher klinischer Untersuchung konnte eine Minderdurchblutung der unteren Extremität schnell und sicher festgestellt werden. Durch die angiologische Intervention konnten die Behandlung von chronischen Wunden verkürzt und die Kosten gesenkt werden.AbstractDespite the high prevalence of arterial occlusive disease, only a few studies have investigated the benefit of interventions to recanalize extremity arteries prior to plastic operations to close chronic wounds. The purpose of this study was to investigate the correlation of simple clinical examinations and apparative diagnostics of arterial occlusive disease of the lower extremity in patients with chronic wounds and to evaluate the benefit of vascular procedures to optimize wound perfusion before surgical closure. A total of 150 individuals with chronic wounds were included in this retrospective study. All patients underwent palpation of their foot pulses, Doppler sonography, and measurement of occlusive pressure. Positive results were tested by angiography. All patients with peripheral extremity vessel occlusion underwent vascular interventions prior to plastic operations for definitive wound closure. In all 34 patients with missing foot pulses, the clinical diagnosis of arterial occlusion could be confirmed by angiography. Peripheral recanalization and improved wound perfusion could be achieved in all patients. Arterial insufficiency could be diagnosed rapidly and safely using simple clinical examination such as palpation of foot pulses or measurement of occlusive pressures combined with Doppler sonography. Thus this simple and straightforward algorithm helped to secure the success of surgical therapy by shortening the time until wound-healing and reducing the psychosocial burden on the patient and financial costs to the health care system.

Primäre chirurgische Therapie bei Verbrennungen

ZusammenfassungDie moderne Verbrennungstherapie, basierend auf allgemein anerkannten Eckpfeilern der Therapie, hat seit der flächendeckenden Einrichtung von Zentren für Schwerbrandverletzte die Überlebensprognose der betroffenen Patienten deutlich verbessern können. Wesentliche Grundlagen einer erfolgreichen Therapie bilden eine adäquate Volumentherapie, eine frühe enterale Ernährung, Infektionskontrolle und die frühe Hautexzision mit autologem Hautersatz. Zu dieser Akutbehandlung gehört zwingend eine frühe Rehabilitation, frühe Reintegration in das Berufs- und Privatleben, Kontrolle der Narbenreifungen, sowie stadiengerechte plastische Korrektur der funktionellen und ästhetischen Folgeerscheinungen.AbstractThe 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.

Early surgical management of severe burns

ZusammenfassungDie moderne Verbrennungstherapie, basierend auf allgemein anerkannten Eckpfeilern der Therapie, hat seit der flächendeckenden Einrichtung von Zentren für Schwerbrandverletzte die Überlebensprognose der betroffenen Patienten deutlich verbessern können. Wesentliche Grundlagen einer erfolgreichen Therapie bilden eine adäquate Volumentherapie, eine frühe enterale Ernährung, Infektionskontrolle und die frühe Hautexzision mit autologem Hautersatz. Zu dieser Akutbehandlung gehört zwingend eine frühe Rehabilitation, frühe Reintegration in das Berufs- und Privatleben, Kontrolle der Narbenreifungen, sowie stadiengerechte plastische Korrektur der funktionellen und ästhetischen Folgeerscheinungen.AbstractThe 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.

Expression of TNF-related apoptosis-inducing ligand (TRAIL) in keratinocytes mediates apoptotic cell death in allogenic T cells

The objective of the present study was to evaluate the aptitude of TRAIL gene expression for inducing apoptosis in co-cultivated T-cells. This should allow preparing a strategy for the development of a durable, allogenic skin substitute based on the induction of an immune-privileged transplant. In order to counteract the significant potential of rejection in transplanted allogenic keratinocytes, we created a murine keratinocyte cell line which expressed TRAIL through stable gene transfer. The exogenic protein was localized on the cellular surface and was not found in soluble condition as sTRAIL. Contact to TRAIL expressing cells in co-culture induced cell death in sensitive Jurkat-cells, which was further intensified by lymphocyte activation. This cytotoxic effect is due to the induction of apoptosis. We therefore assume that the de-novo expression of TRAIL in keratinocytes can trigger apoptosis in activated lymphocytes and thus prevent the rejection of keratinocytes in allogenic, immune-privileged transplants.