Circumferential deep burns carry a high risk for a burn induced compartment syndrome. It was recently shown that an enzymatic bromelain-based debridement with Nexobrid® is a safe and efficient procedure to release pressure in deep circumferential extremity burns reducing the need for surgical escharotomy. We therefore herein aimed to analyze the conceptual relation between Nexobrid® and surgical escharotomy. We conducted a retrospective study on all patients with circumferential deep partial-thickness or full-thickness burns requiring immediate escharotomy that was either performed by surgical incision or Nexobrid®. Medical records of 792 patients that were treated at the burn center of the University Hospital Zurich between 2016 and 2021 were analyzed. Overall, 62 patients with circumferential deep partial-thickness or full-thickness burns who received preventive decompression either by Nexobrid® (N = 29) or surgical escharotomy (N = 33), were included. Whilst distribution of age, sex, BMI and type of injury showed no difference between the groups, the ABSI score, TBSA, percentage of third degree burns and mortality were significantly higher in patients who received a surgical escharotomy. While the use of Nexobrid® to prevent burn induced compartment syndrome has steadily increased, surgical escharotomies were predominantly performed in severely burned patients with a high degree of full-thickness burns. Thus, higher mortality in this patient group needs to be considered with caution and is mainly attributed to the higher TBSA. Although evidence is lacking for the use of Nexobrid® for larger body areas exceeding 15%, escharotomy is also the more reliable and faster approach in such critically burned patients.

Achieving precision in microsurgery requires skill, adequate instruments and magnification, as well as extensive training. Dedicated surgical robotic systems have enhanced and expanded the application of (super-)microsurgical techniques by introducing motion scaling and providing improved surgeon ergonomics. In this prospective preclinical trial, we analyzed the learning curve in robotic assisted microsurgery in 13 participants including medical students, residents, and attending physicians. Data on demographics as well as prior experience in surgery, microsurgery, and gaming were collected. In three study sessions, the participants performed nine microsurgical anastomoses each on 2 mm vessel models using the Symani^® Surgical System in combination the VITOM 3D exoscope. A senior expert microsurgeon reviewed the de-identified and blinded videos and scored all anastomoses using a modified “Structured Assessment of Microsurgical Skills” (SARMS) score. All participants significantly reduced their time needed per anastomosis and their overall SARMS score, as well as individual scores for motion and speed throughout the trial. We saw a significant correlation of prior years of practice in surgery with the overall mean time and mean SARMS score. In a separate analysis of the three sessions, this influence could no longer be seen in the last session. Furthermore, we found no significant effect of gender, age, hand dominance, or gaming experience on speed and quality of the anastomoses. In this study of 117 robotic assisted anastomoses, a rapid improvement of performance of all participants with different surgical skills levels could be shown, serving as encouraging evidence for further research in the implementation of microsurgical robotic systems.

Zusammenfassung: In den letzten Jahren haben speziell für die Mikrochirurgie entwickelte Roboter das Anwendungsgebiet robotisch assistierter Operationen auch in der plastisch-rekonstruktiven Chirurgie erweitert. Derzeit gibt es zwei Mikrochirurgierobotersysteme, welche in der plastischen Chirurgie eingesetzt werden. Beide Systeme verfügen über Technologien zur Tremorreduzierung und Bewegungsskalierung, wodurch die Präzision und Geschicklichkeit des Chirurgen optimiert werden sollen. In der Klinik für Plastische Chirurgie und Handchirurgie des Universitätsspitals Zürich wird das Symani Surgical System® bereits bei vielen mikro- und supermikrochirurgischen Operationen, unter anderem bei autologen Brustrekonstruktionen, Nerventransfers und im Besonderen in der rekonstruktiven Lymphchirurgie, eingesetzt. Trotz spezieller technischer Herausforderungen, beispielsweise einem fehlenden haptischen Feedback, überwiegen nach entsprechendem Training des Mikrochirurgen die Vorteile, dazu zählen insbesondere kleinere Operationszugänge für anatomisch tiefe Strukturen und eine Verbesserung der chirurgischen Präzision.

Vascularized lymph node transfer (VLNT) has become an important surgical technique in the treatment of lymphedema. Considering the different available regions available for flap harvest, we aimed to analyze different donor sites for VLNT with respect to donor site morbidity, impact on limb volume, and patient-reported outcome measurements (PROMs). A single-center prospective study of all patients undergoing VLNT at the Department of Plastic Surgery and Hand Surgery of the University Hospital Zurich between September 2016 and 2023 was conducted. Lymph nodes were harvested either from the omentum (gastroepiploic [GE]-VLNT), the lateral thoracic wall (LTW), or the superficial inguinal region (SI-VLNT). Volume measurements and PROMs were assessed preoperatively and at different postoperative intervals. Overall, 70 patients with upper limb lymphedema (21%) or lower limb lymphedema (79%) with different lymphedema stages were included. There were 49 patients who underwent GE-VLNT, followed by LTW-VLNT (n = 16) and SI-VLNT (n = 5). Lymph node harvest from the SI was associated with a significantly higher frequency of seroma development. The average percentage volume loss related in comparison to the preoperative volume of the affected limb was 9% after GE-VLNT, 10% after LTW-VLNT, and 5% after SI-VLNT without a significant difference between the groups. PROMs revealed significant improvements for physical functioning, symptoms and psychological well-being, with no differences between the VLNT techniques. VLNT leads to a significant improvement of quality of life and can decrease limb volume effectively, regardless of the selection of donor site. GE-VLNT has become our flap of choice owing to its low donor site morbidity and its properties that allow a double transplantation while avoiding a second donor site.

In patients with osteomalacia, a defect in bone mineralization leads to changed characteristics of the bone surface. Considering that the properties of the surrounding matrix influence function and differentiation of cells, we aimed to investigate the effect of osteoidosis on differentiation and function of osteoclasts. Based on osteomalacic bone biopsies, a model for osteoidosis in vitro (OIV) was established. Peripheral blood mononuclear cells were differentiated to osteoclasts on mineralized surfaces (MS) as internal control and on OIV. We observed a significantly reduced number of osteoclasts and surface resorption on OIV. Atomic force microscopy revealed a significant effect of the altered degree of mineralization on surface mechanics and an unmasking of collagen fibres on the surface. Indeed, coating of MS with RGD peptides mimicked the resorption phenotype observed in OIV, suggesting that the altered differentiation of osteoclasts on OIV might be associated with an interaction of the cells with amino acid sequences of unmasked extracellular matrix proteins containing RGD sequences. Transcriptome analysis uncovered a strong significant up‐regulation of transmembrane glycoprotein TROP2 in osteoclastic cultures on OIV. TROP2 expression on OIV was also confirmed on the protein level and found on the bone surface of patients with osteomalacia. Taken together, our results show a direct influence of the mineralization state of the extracellular matrix surface on differentiation and function of osteoclasts on this surface which may be important for the pathophysiology of osteomalacia and other bone disorders with changed ratio of osteoid to bone.