Methacrylated Gelatin as a Scaffold for Mechanically Isolated Stromal Vascular Fraction for Cutaneous Wound Repair.

Mechanically processed stromal vascular fraction (mSVF) is a highly interesting cell source for regenerative purposes, including wound healing, and a practical alternative to enzymatically isolated SVF. In the clinical context, SVF benefits from scaffolds that facilitate viability and other cellular properties. In the present work, the feasibility of methacrylated gelatin (GelMA), a stiffness-tunable, light-inducible hydrogel with high biocompatibility is investigated as a scaffold for SVF in an in vitro setting. Lipoaspirates from elective surgical procedures were collected and processed to mSVF and mixed with GelMA precursor solutions. Non-encapsulated mSVF served as a control. Viability was measured over 21 days. Secreted basic fibroblast growth factor (bFGF) levels were measured on days 1, 7 and 21 by ELISA. IHC was performed to detect VEGF-A, perilipin-2, and CD73 expression on days 7 and 21. The impact of GelMA-mSVF on human dermal fibroblasts was measured in a co-culture assay by the same viability assay. The viability of cultured GelMA-mSVF was significantly higher after 21 days (p < 0.01) when compared to mSVF alone. Also, GelMA-mSVF secreted stable levels of bFGF over 21 days. While VEGF-A was primarily expressed on day 21, perilipin-2 and CD73-positive cells were observed on days 7 and 21. Finally, GelMA-mSVF significantly improved fibroblast viability as compared with GelMA alone (p < 0.01). GelMA may be a promising scaffold for mSVF as it maintains cell viability and proliferation with the release of growth factors while facilitating adipogenic differentiation, stromal cell marker expression and fibroblast proliferation.

Outcome Comparison of Different Reconstructive Approaches for Axillary Defects Secondary to Radical Excision of Hidradenitis Suppurativa.

BACKGROUND: Radical excision of debilitating hidradenitis suppurativa lesions is the only curative approach in the advanced stages of the disease. Different concepts for axillary reconstruction do exist, but data on their clinical outcome are scarce. METHODS: This is a retrospective cohort study of two reconstructive methods (posterior arm flap vs. vacuum-assisted closure [VAC] + split-thickness skin graft [STSG]) for axillary defects in patients with severe axillary hidradenitis suppurativa treated at the University Hospital Zurich between 2005 and 2020. RESULTS: A total of 35 patients (mean age 36 ± 10 years, mean BMI 29 ± 5 kg/m2, Hurley stage II-III) with 67 operated axillae were stratified according to their type of reconstruction. Median operation time in the flap group was 144 min (IQR 114-207) (cumulative 181 min [IQR 124-300]) and 50 min (IQR 40-81) in the VAC + STSG group (cumulative 151 min [IQR 94-194], p < 0.01; p = 0.20 [cumulative time]). The cumulative length of stay was 6 ± 3 days in the flap group and 14 ± 7 days in the VAC + STSG group (p < 0.01). Time to complete wound healing was 27 days (IQR 20-49) in the flap group and 62 days (IQR 41-75) in the VAC + STSG group (p < 0.01). Vancouver Scar Scale score was 6 (IQR 4-9) in the flap group and 11 (IQR 9-12) in the VAC + STSG group (p < 0.01). Protective sensory recovery was most satisfactory in the flap group (p < 0.01). Forty-four percent of patients of the VAC + STSG group demonstrated functional impairment of arm abduction. Time to return to work was less in group A with 42 days (IQR 27-57) needed as compared to group B with 48 days (IQR 34-55) needed (p = 0.32). The average cost saving was 25% higher for the flap group than for the VAC + STSG group. CONCLUSION: Despite an increased operation time, axillary reconstruction by the posterior arm flap yields a reduced length of stay, less time to complete wound healing along with restoration of a protective sensibility, and less axillary scarring avoiding functional deficits - eventually allowing earlier return to work.

Incidence and Time Point of Sepsis Detection as Related to Different Sepsis Definitions in Severely Burned Patients and Their Accompanying Time Course of Pro-Inflammatory Biomarkers.

BACKGROUND: Diagnosis of sepsis in burn patients remains difficult for various reasons. One major problem is the definition of sepsis itself. Therefore, previous and current sepsis definitions are a matter of ongoing validation, but a well-defined consensus on which clinical and laboratory parameters to incorporate in such a definition is lacking. The aim of the present study was to compare the incidence and time-related occurrence of septic events according to different definitions as well as their accompanying time course of pro-inflammatory biomarkers. METHODS: Across the first 14 days after admission, the incidence and time point of sepsis according to three different definitions (Sepsis-3, Sepsis American Burns Association [ABA] 2007, Sepsis Zurich Burn Center) were assessed on a daily basis in adult burn patients with total body surface area (TBSA) ≥15% admitted to the Zurich Burn Center between May 2015 and October 2018. In order to investigate how well daily drawn proinflammatory biomarkers (white blood cells (WBCs), C-reactive protein (CRP), procalcitonin (PCT), and novel pancreatic stone protein (PSP)) reflect the progression of sepsis depending on its type of definition, a longitudinal mixed model analysis was performed across the first 14 days for septic and non-septic patients. Additionally, the relative increase of biomarker levels 24, 48, and 72 h prior to a septic event was analyzed for each definition used. RESULTS: In our cohort of 90 severely burned patients, Sepsis-3 identified 46 patients (51.1%) as septic, while ABA 2007 and the Zurich Burn Center definition counted 33 patients (36.7%) and 24 patients (26.6%), respectively. Sepsis-3 detected sepsis about 1 day earlier than Sepsis ABA 2007 (p < 0.001) and about 0.5 days earlier than Sepsis Zurich Burn Center (p = 0.04). The course of pro-inflammatory biomarkers was largely unaffected by the type of sepsis definition. Irrespective of the sepsis definition, PSP was the only marker to demonstrate a highly significant interaction between time and group (sepsis versus no sepsis) (p < 0.001) with a 3.3-5.5-fold increase within 72 h before the event of sepsis, whereas CRP, PCT, and WBC showed only mild undulations. CONCLUSIONS: Despite the ongoing dilemma of how to define sepsis in burn patients, a continually calculated SOFA score as used in Sepsis-3 is advantageous to early identify a patient's detrimental progression to sepsis. Inclusion of biomarkers, such as PSP, may help support the burn specialist's diagnosis of sepsis and could improve the diagnostic performance of current and future definitions in burn patients.

Pancreatic Stone Protein Predicts Sepsis in Severely Burned Patients Irrespective of Trauma Severity: A Monocentric Observational Study.

OBJECTIVE: The burn victim's inherent state of hyperinflammation frequently camouflages septic events delaying the initiation of targeted intensive care therapy. Accurate biomarkers are urgently needed to support sepsis detection before patients' clinical deterioration. SUMMARY OF BACKGROUND DATA: Evidence on the usefulness of pancreatic stone protein (PSP) as a powerful diagnostic and prognostic marker in critically ill patients has recently accumulated. METHODS: Analysis of biomarker kinetics (PSP, routine markers) was performed on 90 patients admitted to the Zurich Burn Center between May 2015 and October 2018 with burns ≥15% total body surface area with regard to infection and sepsis (Sepsis-3) over a 14-day time course. RESULTS: PSP differentiated between sepsis, infection and sterile inflammation from day 3 onward with an area under the curve of up to 0.89 (P < 0.001), therefore, competing with procalcitonin (area under the curve = 0.86, P < 0.001). Compared to routine inflammatory biomarkers, only PSP demonstrated a significant interaction between time and presence of sepsis - signifying a steeper increase in PSP levels in septic patients as opposed to those exhibiting a nonseptic course (interaction P < 0.001). Event-related analysis demonstrated tripled PSP serum levels within 72 hours and doubled levels within 48 hours before a clinically apparent sepsis. CONCLUSION: PSP is able to differentiate between septic and nonseptic patients during acute burn care. Its steep rise up to 72 hours before clinically overt deterioration has the potential for physicians to timely initiate treatment with reduced mortality and costs.

Contemporary Concepts of Primary Dynamic Facial Nerve Reconstruction in the Oncologic Patient.

Transection of the facial nerve and its branches during extensive ablative procedures in the oncologic patient causes loss of control of facial mimetic muscles with severe functional and aesthetic sequelae. In such patients with advanced tumorous disease, copious comorbidities, and poor prognosis, rehabilitation of the facial nerve has long been considered of secondary priority. However, recent advances in primary facial nerve reconstruction after extensive resection demonstrated encouraging results focusing on rapid and reliable restoration of facial functions. The authors summarize 3 innovative approaches of primary dynamic facial nerve reconstruction by using vascularized nerve grafts, dual innervation concepts, and intra-facial nerve transfers.

The International Fellowship Program in Microsurgery at Uppsala University Hospital: A Paragon Throughout Europe.

Personal reports with valuable information on plastic surgery fellowships from all over the world are about to accumulate in recent years. Whereas some institutions have rightly become widely renowned for their excellent microsurgery fellow training in Taiwan, Canada, United States, and Australia, less is known about European fellowships focusing on reconstructive microsurgery. As former fellow at the Department of Plastic and Maxillofacial Surgery at Uppsala University Hospital, Sweden, the author hereby presents a survey on a unique and exemplary 6-month microsurgical fellowship offering hands-on training, academic education, and not last personal development to ambitious candidates who pursue a career in reconstructive microsurgery.

Sonographic study of repair, gapping and tendon bowstringing after primary flexor digitorum profundus repair in zone 2.

We report sonographic findings with clinical outcomes after zone 2 flexor digitorum profundus tendon repairs in ten fingers. The tendons underwent a six-strand M-Tang core repair, no circumferential suture, and partial or complete division of the pulleys. Over 12 months after surgery and using ultrasound, we found no gapping at the repair site during finger motion. When the pulleys were divided, there was sonographic evidence of tendon bowstringing, but the bowstringing was minimal. Clinically, we did not find any fingers that displayed tendon bowstringing or had functional loss. With ultrasound examination, the repaired tendons remained enlarged over 12 months. Two patients developed heterotopic ossifications at the repair site without tendon gliding, and these required tenolysis. We conclude that the tendon repair site does not gap when a strong core suture is used in the repair without adding peripheral sutures. There is no notable tendon bowstringing clinically, though the repaired tendons have sonographic evidence of minor bowstringing. LEVEL OF EVIDENCE: III.

Diagnosis and perioperative management of ruptured AAA mimicking symptomatic groin hernia.

INTRODUCTION: Ruptured abdominal aortic aneurysm (RAAA) can infrequently present as symptomatic groin hernia. This misleading form of presentation often leads to erroneous preoperative management resulting in poor survival. CASE PRESENTATION: Two patients with RAAA mimicking symptomatic groin hernia underwent different preoperative managements pointing out the importance of the principles of hypotensive haemostasis in the scope of this emergency scenario. CONCLUSION: Computed Tomography Angiography (CTA) remains the recommended diagnostic tool-for both safe diagnosis of the ruptured aneurysm and precise preoperative planning. Endovascular aortic repair of the RAAA-if feasible-is the treatment of choice. This rare form of RAAA manifestation should call physicians attention-especially in patients with known abdominal aortic aneurysms in their preceding medical history.