Erstellung von Wundspannungsgrenzwerten mit einem neu entwickelten Wundtensiometer

Objective To (i) quantitatively measure wound tension in experimental skin wounds using a newly developed wound tensiometer and (ii) establish reference values for primary skin wound closure in medium- and large-breed dogs. Study design Experimental cadaveric study. Animal population Nineteen dogs of medium to large breeds (BW 20 to 40 kg). Methods Elliptical skin wounds of different sizes were created on the chest and abdomen. The wounds were gradually enlarged. Experienced surgeons (ECVS diplomates or professors of small animal surgery) and inexperienced surgeons (1st year after graduation) independently assessed wound tension through manual manipulation and determined whether the wound could be closed without tension-relieving measures. In addition, wound tension was objectively quantified using a newly developed wound tensiometer. Results The upper threshold for wound tension at which direct appositional wound closure was recommended by the experienced surgeons was 5.4 N, and the median minimal tension without recommendations for closure was 6.0 N. The data also demonstrate that wound tension and wound size do not necessarily correlate, and inexperienced surgeons need to develop a feel for wound tension. Conclusion The intraoperative use of the wound tensiometer, in combination with established cut-off values, might facilitate decision-making regarding primary wound closure. Clinical relevance The findings of this study provide evidence for the applicability of a wound tensiometer in guiding inexperienced surgeons in their choice of the skin wound closure method.Ziel (i) Report über die quantitative Messung der Wundspannung bei experimentellen Hautwunden unter Verwendung eines neu entwickelten Wundtensiometers und (ii) Entwicklung von Referenzwerten für den primären Hautwundverschluss bei Hunden mittlerer und großer Rassen. Studienaufbau Experimentelle Studie an Kadavern. Tierpopulation Neunzehn Hunde mittelgroßer bis großer Rassen (KG 20 bis 40 kg). Methoden Es wurden elliptische Hautwunden unterschiedlicher Größe an den Brust- und Bauchwänden der Hunde erzeugt. Erfahrene Chirurgen (ECVS-Diplomates oder Professoren für Kleintierchirurgie) sowie unerfahrene Chirurgen (im ersten Jahr nach Studienabschluss) beurteilten unabhängig voneinander die Wundspannung durch manuelle Manipulation und wurden gebeten zu entscheiden, ob die Wunde durch einen einfachen Wundverschluss ohne Verwendung von spannungsentlastenden Maßnahmen verschlossen werden sollte oder nicht. Im Vergleich dazu wurde die Wundspannung objektiv mit einem neu entwickelten Wundtensiometer quantifiziert. Ergebnisse Der obere Grenzwert für die Hautwundspannung, bei dem ein direkter appositioneller Wundverschluss von den erfahrenen Chirurgen empfohlen wurde, lag bei 5,4 N und der Median der minimalen Spannung ohne Empfehlungen zum einfachen Wundverschluss bei 6,0 N. Zudem zeigen die Ergebnisse, dass Wundspannung und Wundgröße nicht unbedingt korrelieren und dass unerfahrene Chirurgen ein Gefühl für die Wundspannung entwickeln müssen. Schlussfolgerung In Zukunft könnte die intraoperative Verwendung des Wundtensiometers in Kombination mit den ermittelten Cut-off-Werten die Entscheidungsfindung hinsichtlich des primären Wundverschlusses erleichtern. Klinische Relevanz Die Ergebnisse dieser Studie liefern Belege für die Anwendbarkeit eines Wundtensiometers zur Unterstützung unerfahrener Chirurgen bei der Wahl der Methode zum Verschluss von Hautwunden

Mechanical Interventions In Soft Tissue Repair

This body of work sets to investigate some of these mechanical interventions that are designed to promote wound healing, repair, or even replace an injured tissue. By investigating three separate tissues and three separate mechanical interventions, we can draw conclusions about the implications of including mechanical interventions in biomedical research and clinical treatments. The use of sutures to close wounds is highly common, however the effects of sutures on the tensile mechanics of human skin are largely unknown. To evaluate how sutures may affect uniaxial tensile mechanics, human skin samples were sutured and loaded in tension in multiple orientations. The data suggested that the sutured skin had a lower fracture strength and higher elastic modulus than the intact skin, particularly when loaded in-line with the injury. Next, the inflammatory effects of a decellularized ECM patch in a myocardial infarction model were analyzed. A commercially available decellularized material, porcine small intestine submucosa, was evaluated as a patch treatment in a rat myocardial infarction model, a treatment that is common in cardiac research. As anticipated, the addition of the patch in the injury area increased local inflammation as indicated by gene expression and leukocyte population and density. However, the patch did not appear to extend the inflammation response nor affect the response in a manner that would suggest hindrance to wound healing. Thirdly, a unique biochemical and mechanical approach was used to direct human adipose stem cells to differentiate towards a meniscus-like phenotype. By using a variety of media formulations and a variation of uniaxial tensile parameters, a protocol to maximize meniscus gene expression was concluded. A chondrogenic media formulation with 10% uniaxial strain at 1 Hz for 3 hours was found to have the greatest increase in meniscus gene expression of all of the parameters tested. Together, each of these individual works contributes to the conclusion that mechanical interventions can have a significant impact on the restructuring, repair, and replacement of soft tissues