Arm lymphedema after vascularized lymph node harvest following Covid-19 vaccination

There is evidence that COVID-19 vaccines may affect the lymphatic system. We report a case of a 40-year-old female who had undergone lymph node transfer for treating primary lymphedema of the legs. Six months later, the patient developed lymphedema of the right arm closely related to mRNA vaccination against COVID-19.

100 anastomoses: a two-year single-center experience with robotic-assisted micro- and supermicrosurgery for lymphatic reconstruction

Robotic-assisted microsurgery has gained significant attention in recent years following the introduction of two dedicated microsurgical robotic systems specifically designed for this purpose. These feature higher degrees of movement and motion scaling which are useful tools, especially when performing surgery in areas of the body which are difficult to access. Robotic-assisted microsurgery has been implemented in lymphatic surgery as well as soft tissue reconstructive surgery at our institution over the past 2.5 years. Our study gives an insight into the details and outcomes of the first 100 consecutive (super-) microsurgical anastomoses in peripheral and central lymphatic reconstruction performed with the Symani® Surgical System between 2021 and 2024. In total, 67 patients were treated, receiving robotic-assisted lymphatic reconstruction with lymphatic tissue transfer (LTT) and/or lymphovenous anastomoses (LVA)/lympholymphatic anastomoses (LLA). No anastomosis-associated complications were recorded postoperatively. The majority of patients reported a postoperative improvement of their lymphedema or central lymphatic disorder. In conclusion, we show the successful implementation of the Symani® Surgical System into our clinical practice of lymphatic reconstruction. Although the necessary intraoperative setup and the use of intrinsic motion scaling lead to a slight increase in operating time, the presented study demonstrates the advantages of robotic assistance which becomes particularly evident in lymphatic surgery due to the involved deep surgical sites and the need for supermicrosurgical techniques.

[Robotic-Assisted Lymphatic Surgery]

Surgical robotic systems specifically developed for microsurgery are increasingly being used in recent years, particularly in reconstructive lymphatic surgery. Currently, there are two robotic systems that are used in microsurgery. Both systems feature tremor reduction and motion scaling technologies, which are intended to optimise the surgeon's precision and dexterity. In the Department of Plastic Surgery and Hand Surgery at the University Hospital Zurich, the Symani Surgical System is used in many microsurgical and supermicrosurgical procedures. It is mainly used in reconstructive lymphatic surgery, especially for robotic-assisted lymphovenous anastomosis, microvascular anastomosis of lymph node flaps, and it is used in central lymphatic surgery. The robot enables smaller surgical approaches for deep anatomical structures with enhanced surgical precision. In combination with an exoscope, it can also improve the ergonomics of the microsurgeon.

Thromboembolic events in burn patients: An analysis of risk factors and different anticoagulants

BACKGROUND

Burn patients are in a state of activated coagulation, putting them at risk for thromboembolic events. Additionally, certain patient-related factors are associated with an increased risk of thrombus formation. This study aimed to evaluate the incidence of thromboembolic events and identify potential risk factors, including patient characteristics, surgical treatment, anticoagulation strategies, and laboratory parameters.

METHODS

A single-centre retrospective cohort study was conducted on all patients with burns treated between 2002 and 2020. Medical reports of patients with and without thromboembolic events were descriptively analysed. The association of time to thromboembolic events with total body surface area (TBSA) was assessed by cause-specific Cox models adjusted for different covariates. The association of time to thromboembolic events with type and dosage of anticoagulants was assessed using a cause-specific Cox proportional hazards model with time-dependent covariates, applied to a matched subset of patients.

RESULTS

The incidence of thromboembolic events was 8.1% in a cohort of 642 patients. We found a statistically significant increase in the hazard for thromboembolic events by a factor of 1.02 (95% CI 1.00 to 1.03; P ≤ 0.05) per percent increase in TBSA. We identified former alcohol abuse (HR=2.54, CI 1.33 to 4.84, P = 0.005) and higher body mass index (HR=1.06, 95% CI 1.00 to 1.12, P = 0.046) as potential risk factors for the development of thromboembolic events. We further noted inadequate median anti-Factor-X activity levels and elevated C-reactive protein and procalcitonin levels at the time of the event.

CONCLUSION

Our results showed a moderate risk of thromboembolic events among burn patients, underlining the importance of close monitoring with regard to thrombus formation. In particular, patients with higher TBSA, alcohol abuse and BMI may be evaluated more regularly for thromboembolic events. Anti-Factor-X activity levels should be determined regularly and therapy should be adjusted if necessary.

A quadriphasic mechanical model of the human dermis

The present study investigates the multiphasic nature of the mechanical behavior of human dermis. Motivated by experimental observations and by consideration of its composition, a quadriphasic model of the dermis is proposed, distinguishing solid matrix components, interstitial fluid and charged constituents moving within the fluid, i.e., anions and cations. Compression and tensile experiments with and without change of osmolarity of the bath are performed to characterize the chemo-mechanical coupling in the dermis. Model parameters are determined through inverse analysis. The computations predict a dominant role of the permeability in the determination of the temporal evolution of the mechanical response of the tissue. In line with the previous studies on other tissues, the analysis shows that an ideal model based on Donnan's equilibrium overestimates the osmotic pressure in skin for the case of very dilute solutions. The quadriphasic model is applied to predict changes in dermal cell environment and therefore alterations in what is called the "mechanome," associated with skin stretch. The simulations indicate that skin deformation causes a variation in several local variables, including in particular the electric field associated with a deformation-induced non-homogeneous distribution of fixed charges.

CD112 Supports Lymphatic Migration of Human Dermal Dendritic Cells

Dendritic cell (DC) migration from peripheral tissues via afferent lymphatic vessels to draining lymph nodes (dLNs) is important for the organism's immune regulation and immune protection. Several lymphatic endothelial cell (LEC)-expressed adhesion molecules have thus far been found to support transmigration and movement within the lymphatic vasculature. In this study, we investigated the contribution of CD112, an adhesion molecule that we recently found to be highly expressed in murine LECs, to this process. Performing in vitro assays in the murine system, we found that transmigration of bone marrow-derived dendritic cells (BM-DCs) across or adhesion to murine LEC monolayers was reduced when CD112 was absent on LECs, DCs, or both cell types, suggesting the involvement of homophilic CD112-CD112 interactions. While CD112 was highly expressed in murine dermal LECs, CD112 levels were low in endogenous murine dermal DCs and BM-DCs. This might explain why we observed no defect in the in vivo lymphatic migration of adoptively transferred BM-DCs or endogenous DCs from the skin to dLNs. Compared to murine DCs, human monocyte-derived DCs expressed higher CD112 levels, and their migration across human CD112-expressing LECs was significantly reduced upon CD112 blockade. CD112 expression was also readily detected in endogenous human dermal DCs and LECs by flow cytometry and immunofluorescence. Upon incubating human skin punch biopsies in the presence of CD112-blocking antibodies, DC emigration from the tissue into the culture medium was significantly reduced, indicating impaired lymphatic migration. Overall, our data reveal a contribution of CD112 to human DC migration.

Robotic Microsurgery in Extremity Reconstruction - Experience With a Novel Robotic System

Background: Robotic systems have successfully been introduced into other surgical fields in the past. First attempts with different setups are made in the field of microsurgery. The Symani® Surgical System, a flexible platform consisting of two robotic arms, features motion scaling with tremor filtration to address the demands and complexity of microsurgery. Symani's NanoWrist Instruments are the world's smallest, wristed surgical instruments, intended to improve a surgeon's range of motion beyond the capability of the human hand. This combination allows surgeons to scale their hand movements while seamlessly articulating the robotic micro instruments. Purpose: We report on our experience in extremity reconstruction with this novel system.Research Design: The Symani Surgical System® was used for 6 cases of extremity reconstruction. The surgeon controlled the manipulators along with the footswitch while either sitting away from the operating table relying on 3D visualization with an exoscope or sitting at the operating table using a standard microscope.Data Collection: Microsurgical anastomoses were performed in 4 patients (3 end-to-end arterial anastomoses and one end-to-side arterial anastomosis) and nerve grafting was performed in 2 patients.Results: Microvascular anastomoses were slower vs conventional microsurgery, but all anastomoses were patent. Epineural coaptation showed proper fascicle alignment and tissue manipulation could be kept to a minimum. The platform's motion scaling allows the surgeon to perform precise micro-movements with only minimal tissue manipulation and hard-to-reach anatomy becomes accessible more easily.Conclusions: Robotic microsurgery might gain importance in the nearer future but more data will need to be collected.

Prevalence and Prognostic Role of Lymphedema in Patients with Deep Venous Thrombosis and Thrombophlebitis

Background: Deep venous thrombosis (DVT) poses a substantial disease burden. Lymphedema may present with similar symptoms making the diagnosis process more difficult. Data on the epidemiology of lymphedema are lacking. Methods: The German nationwide inpatient sample served to analyze all patients hospitalized owing to DVT and/or thrombophlebitis (referred to as DVT) of the legs in Germany between 2005 and 2020. We stratified these patients for additional lymphedema and analyzed the impact of lymphedema on adverse in-hospital events. Results: Overall, 1,136,574 hospitalizations related to DVT were recorded in Germany during 2005-2020 (53.3% women; 51.3% aged ≥70 years). Lymphedema was coded in 9974 (0.9%) patient-cases (82.0% not elsewhere classified, 17.7% secondary lymphedema). Annual numbers of hospitalizations with lymphedema among DVT patients increased from 450 (2005) to 613 (2016) (β 0.57; 95% confidence interval [CI]: 0.48-0.66], p < 0.001) and decreased thereafter. Despite similar age, DVT patients with lymphedema had higher prevalence of cardiovascular diseases, chronic organ failure, and all types of investigated cancer. Prevalence of pulmonary embolism (PE) with shock/CPR (4.1% vs. 1.5%), acute renal failure (6.7% vs. 2.5%), and stroke (5.2% vs. 4.2%) was higher in DVT patients with lymphedema than without. Lymphedema was independently associated with PE with shock/CPR (OR: 2.1; 95% CI: 1.9-2.3) as well as death (OR: 1.3; 95% CI: 1.2-1.4). Conclusions: Comorbidity conditions like cancer, obesity, and cardiovascular risk factors, and also infectious complications, were more prevalent in DVT patients with lymphedema than in those without. Lymphedema was independently associated with severe in-hospital complications, particularly when its genesis was related to severe comorbidities.

Measuring quality of care in autologous breast reconstruction: a Delphi consensus

Measuring and benchmarking quality of care in surgical oncology has been gaining popularity. In autologous breast reconstruction (ABR), a standardized set of indicators to assess quality of care is lacking. In this study, we defined a set of evidence-based quality indicators for autologous breast reconstruction. First, we performed a systematic review to identify factors related to quality of care in ABR. Variables were categorized depending on their function: indicators related to outcome, indicators related to process and case-mix variables. The review was followed by a 3-round Delphi Consensus to determine which indicators and case-mix-variables were considered relevant and feasible for inclusion in an ABR standard set of indicators. 932 unique articles were identified, of which 110 papers were included in the study. Indicators were categorized by function: outcome, process and case-mix variables. In total, 8 process indicators and 41 outcome indicators were extracted. 30 case-mix-variables were included. Following 3 rounds of questioning in the Delphi Consensus, all respondents agreed on type of ABR, oncological outcomes and patient satisfaction for the standard set. Indicators related to complications were consistently ranked highly. Most process indicators were not chosen after 3 rounds of questioning. 11 case-mix-variables were included in the final set. Following the Delphi Consensus, it was possible to identify 33 process and outcome indicators and 11 case-mix-variables for inclusion for a standard set of quality indicators. With the inclusion of both objective and patient-reported outcome measures, this set of indicators provides a multidimensional measurement tool for quality assessment for ABR.

Impact of a High-Fat Diet at a Young Age on Wound Healing in Mice

As the prevalence of juvenile-onset obesity rises globally, the multitude of related health consequences gain significant importance. In this context, obesity is associated with impaired cutaneous wound healing. In experimental settings, mice are the most frequently used model for investigating the effect of high-fat diet (HFD) chow on wound healing in wild-type or genetically manipulated animals, e.g., diabetic ob/ob and db/db mice. However, these studies have mainly been performed on adult animals. Thus, in the present study, we introduced a mouse model for a juvenile onset of obesity. We exposed 4-week-old mice to an investigational feeding period of 9 weeks with an HFD compared to a regular diet (RD). At a mouse age of 13 weeks, we performed excisional and incisional wounding and measured the healing rate. Wound healing was examined by serial photographs with daily wound size measurements of the excisional wounds. Histology from incisional wounds was performed to quantify granulation tissue (thickness, quality) and angiogenesis (number of blood vessels per mm2). The expression of extracellular matrix proteins (collagen types I/III/IV, fibronectin 1, elastin), inflammatory cytokines (MIF, MIF-2, IL-6, TNF-α), myofibroblast differentiation (α-SMA) and macrophage polarization (CD11c, CD301b) in the incisional wounds were evaluated by RT-qPCR and by immunohistochemistry. There was a marked delay of wound closure in the HFD group with a decrease in granulation tissue quality and thickness. Additionally, inflammatory cytokines (MIF, IL-6, TNF-α) were significantly up-regulated in HFD- when compared to RD-fed mice measured at day 3. By contrast, MIF-2 and blood vessel expression were significantly reduced in the HFD animals, starting at day 1. No significant changes were observed in macrophage polarization, collagen expression, and levels of TGF-β1 and PDGF-A. Our findings support that an early exposition to HFD resulted in juvenile obesity in mice with impaired wound repair mechanisms, which may be used as a murine model for obesity-related studies in the future.

Human amniotic membranes as an allogenic biological dressing for the treatment of burn wounds: Protocol for a randomized-controlled study

Background

Burn wounds pose significant challenges in medical treatment due to their devastating nature and resource-intensive requirements. Temporary coverage of burn wounds using synthetic or biological dressings allows for reepithelization before definitive skin grafting. Allogenic skin grafts have been widely used but come with drawbacks such as rejection and disease transmission. The use of amniotic membranes (AMs) offers a promising alternative for temporary coverage, as they possess biological properties that promote faster healing and improved scar quality. The various components of the amniotic membrane, including pluripotent stem cells, extracellular matrix proteins, and regenerative factors, contribute to cell growth, migration, and differentiation, as well as preservation of the original epithelial phenotype.

Objective

Reliable information on the treatment of burn wounds with AM is needed. The knowledge gained in this project may help to include this advantageous modern concept of biological dressings in clinical practice. The purpose of this study is to use human amniotic membranes from our in hospital laboratory, as an allogenic biological dressing after enzymatic debridement in superficial partial thickness, deep partial thickness or full thickness burn wounds.

Methods

We will include 30 patients in a randomized-controlled trial with each patient receiving the study intervention and the control intervention. Two 7 × 7 cm burn wound areas will be compared regarding percentage of skin graft take, healing time, healing percentage value and total healing time. Human amniotic membranes will be compared to allogenic skin grafts.

First-in-human Use of a Microsurgical Robotic System for Central Lymphatic Reconstruction

Advances in the development of robotic systems have recently enabled the use of robotic technology in reconstructive lymphatic surgery. Although the advantages of microsurgical robots must be weighed carefully against the costs, their use may allow for smaller surgical approaches and easier access to anatomically deeper structures or even smaller vessels. We report on a case of a patient with central lymphatic dilation causing abdominal pain and severely reduced physical capacity. Sonography-assisted intranodal injection of indocyanine green allowed for localization of the lymphatic cyst and anastomosis with the left ovarian vein, applying robotic-assisted microsurgery for the first time on the central lymphatic system. Following the successful reconstruction of lymphatic drainage and decompression of the cyst, the patient reported a complete regression of her preoperative symptoms. From a surgical point of view, the Symani Surgical System improved precision and allowed significantly smaller surgical access. Considering the high morbidity and rarity of pathologies of the central lymphatic system, central lymphatic surgery is to date rarely performed. With improved precision and significantly smaller surgical access, robotic-assisted microsurgery has great potential to expand the treatment options for central lymphatic lesions.

Involvement of the Macrophage Migration Inhibitory Factor (MIF) in Lipedema

Lipedema is a chronic disorder that mainly affects women. It is often misdiagnosed, and its etiology remains unknown. Recent research indicates an accumulation of macrophages and a shift in macrophage polarization in lipedema. One known protein superfamily that contributes to macrophage accumulation and polarization is the macrophage migration inhibitory factor (MIF) family. MIF-1 and MIF-2 are ubiquitously expressed and also regulate inflammatory processes in adipose tissue. In this study, the expression of MIF-1, MIF-2 and CD74-a common receptor for both cytokines-was analyzed in tissue samples of 11 lipedema and 11 BMI-matched, age-matched and anatomically matched control patients using qPCR and immunohistochemistry (IHC). The mRNA expression of MIF-1 (mean 1.256; SD 0.303; p = 0.0485) and CD74 (mean 1.514; SD 0.397; p = 0.0097) were significantly elevated in lipedema patients, while MIF-2 expression was unaffected (mean 1.004; SD 0.358; p = 0.9718). The IHC analysis corroborated the results for CD74 expression on a cellular level. In conclusion, our results provide first evidence for a potential involvement of the MIF family, presumably via the MIF-1-CD74 axis, in lipedema.

Multiscale mechanical analysis of the elastic modulus of skin

The mechanical properties of the skin determine tissue function and regulate dermal cell behavior. Yet measuring these properties remains challenging, as evidenced by the large range of elastic moduli reported in the literature-from below one kPa to hundreds of MPa. Here, we reconcile these disparate results by dedicated experiments at both tissue and cellular length scales and by computational models considering the multiscale and multiphasic tissue structure. At the macroscopic tissue length scale, the collective behavior of the collagen fiber network under tension provides functional tissue stiffness, and its properties determine the corresponding elastic modulus (100-200 kPa). The compliant microscale environment (0.1-10 kPa), probed by atomic force microscopy, arises from the ground matrix without engaging the collagen fiber network. Our analysis indicates that indentation-based elasticity measurements, although probing tissue properties at the cell-relevant length scale, do not assess the deformation mechanisms activated by dermal cells when exerting traction forces on the extracellular matrix. Using dermal-equivalent collagen hydrogels, we demonstrate that indentation measurements of tissue stiffness do not correlate with the behavior of embedded dermal fibroblasts. These results provide a deeper understanding of tissue mechanics across length scales with important implications for skin mechanobiology and tissue engineering. STATEMENT OF SIGNIFICANCE: Measuring the mechanical properties of the skin is essential for understanding dermal cell mechanobiology and designing tissue-engineered skin substitutes. However, previous results reported for the elastic modulus of skin vary by six orders of magnitude. We show that two distinct deformation mechanisms, related to the tension-compression nonlinearity of the collagen fiber network, can explain the large variations in elastic moduli. Furthermore, we show that microscale indentation, which is frequently used to assess the stiffness perceived by cells, fails to engage the fiber network, and therefore cannot predict the behavior of dermal fibroblasts in stiffness-tunable fibrous hydrogels. This has important implications for how to measure and interpret the mechanical properties of soft tissues across length scales.

Benefits of robotic-assisted lymphatic microsurgery in deep anatomical planes

Micro- and supermicrosurgeries have become standard techniques for lymphatic reconstruction. As increasingly smaller vessels are being targeted, robotic-assisted surgery has emerged as a new approach to push reconstructive limits owing to its ability of motion scaling and providing better accessibility of deep anatomical regions. The precision of the robot is achieved at the expense of operating speed among other variables; therefore, the surgeon must weigh the enhanced dexterity against the additional operating time and cost required for the robotic surgical system itself to ensure optimal resource utilization. Here we present a case series of 8 patients who underwent robot-assisted lymphatic microsurgery for omental flap transfer to the axilla and lympho-venous anastomosis. The Symani® Surgical System was used with a conventional microscope or 3D exoscope. The use of 3D exoscope provided clear benefits in terms of surgeon positioning. Moreover, access to the recipient vessels near the thoracic wall was significantly improved with the robotic setup. In addition, suture precision was excellent, resulting in patent anastomoses. Operating time for anastomosis was comparable to that for manual anastomosis and demonstrated a steep learning curve. The benefits of robotic systems in operating fields with good exposure require further evaluation. However, owing to longer instruments, additional stability, dexterity, and motion precision, robotic systems offer a marked advantage for operating in deep anatomical planes and on small structures. A potentially new field for the implementation of robotic surgery is central lymphatic reconstruction. Progress in terms of operating time and cost is crucial, and future research should validate the effectiveness of robotic-assisted surgery in larger clinical studies.

Basic Principles in the Management of Acute Burn Injuries in Adults

INTRODUCTION

This review outlines an overview of up-to-date, stage-appropriate treatment methods for burn injuries as practiced at the National Burn Center of the University Hospital Zurich. It intends to provide practitioners with recommendations for the management of acute minor to severe burn injuries based on scientific evidence as well as the long-term experience of the Burn Center. The focus is on a practical guideline and various options including novel, innovative conceptual approaches.

PROMs after Lymphatic Reconstructive Surgery: Is There a Correlation between Volume Reduction and Quality of Life?

Patients with upper limb lymphedema and lower limb lymphedema experience a wide range of physical and psychological symptoms that affect quality of life. The benefits of lymphatic reconstructive surgery for patients with lymphedema are undisputed. However, recording volume reduction alone may be insufficient with regard to postoperative outcome because measurements are often inadequate, depend on many factors, and do not reflect improvement in quality of life.

Methods

We conducted a prospective single center study patients receiving lymphatic reconstructive surgery. Patients received volume measurements preoperatively and at standardized postoperative intervals. To evaluate patient-reported outcomes, patients completed the following questionnaires: LYMPH-Q Upper Extremity Module, quickDASH, SF 36, Lymphoedema Functioning, Disability and Health Questionnaire for Lower Limb Lymphoedema, and Lower Extremity Functional Scale at the aforementioned intervals.

Results

We included 55 patients with upper limb lymphedema (24%) and lower limb lymphedema (73%) of lymphedema grades I-III. Patients received lymphovenous anastomosis only (23%), free vascularized lymph node transfer (35%) or a combination of both (42%). Analysis of patient-reported outcome measurements revealed improvements with respect to a broad range of complaints, particularly physical function, symptoms, and psychological well-being. There was no correlation between the extent of volume reduction and improvement in quality of life (Pearson correlation coefficient below ±0.7; P > 0.05).

Conclusions

Based on a broad range of outcome measurements, we observed an improved quality of life in almost all patients, even in those without measurable volume loss of the extremity operated on, which emphasizes the need for a standardized use of patient-reported outcome measures to evaluate the benefits of lymphatic reconstructive surgery.

A Comparative Analysis to Dissect the Histological and Molecular Differences among Lipedema, Lipohypertrophy and Secondary Lymphedema

Lipedema, lipohypertrophy and secondary lymphedema are three conditions characterized by disproportionate subcutaneous fat accumulation affecting the extremities. Despite the apparent similarities and differences among their phenotypes, a comprehensive histological and molecular comparison does not yet exist, supporting the idea that there is an insufficient understanding of the conditions and particularly of lipohypertrophy. In our study, we performed histological and molecular analysis in anatomically-, BMI- and gender-matched samples of lipedema, lipohypertrophy and secondary lymphedema versus healthy control patients. Hereby, we found a significantly increased epidermal thickness only in patients with lipedema and secondary lymphedema, while significant adipocyte hypertrophy was identified in both lipedema and lipohypertrophy. Interestingly, the assessment of lymphatic vessel morphology showed significantly decreased total area coverage in lipohypertrophy versus the other conditions, while VEGF-D expression was significantly decreased across all conditions. The analysis of junctional genes often associated with permeability indicated a distinct and higher expression only in secondary lymphedema. Finally, the evaluation of the immune cell infiltrate verified the increased CD4+ cell and macrophage infiltration in lymphedema and lipedema respectively, without depicting a distinct immune cell profile in lipohypertrophy. Our study describes the distinct histological and molecular characteristics of lipohypertrophy, clearly distinguishing it from its two most important differential diagnoses.

Complications arising from aesthetic surgery procedures in foreign countries and Switzerland

BACKGROUND

Cosmetic surgery tourism has increased in popularity in recent years, with arising complications and post-operative follow-up care often managed in the client's home country, thereby burdening the Swiss health care system.

METHODS

We retrospectively reviewed patients with complications after cosmetic surgeries abroad and in Switzerland who were treated at the University Hospital Zurich between 2015 and 2019. Data were collected from medical records and reviewed for patient characteristics, procedures, complications, and treatment modalities.

RESULTS

A total of 228 patients (207 females and 21 males) were identified with female mean age of 40.9±12.0 years and male mean age of 34.3±8.9 years. Most complications were observed for procedures performed in Europe (69%) with only thirty-six patients (16%) experiencing complications due to a procedure undertaken in Switzerland. Breast surgery was the most frequently performed procedure (60%), followed by body contouring (17%) and facial surgery (12%). The most common complications occurring after surgeries abroad were pain and discomfort (19%) as well as aesthetic dissatisfaction (18%), followed by wound breakdown (14%) and infection (11%). Most patients (76%) were treated as outpatients and the treatment of all patients over the observed period cost the healthcare system $ 795,574.

CONCLUSIONS

There is an ongoing trend of cosmetic surgery tourism leading to an increasing number of patients with complications requiring aftercare in Switzerland. In contrast to previous research, more men are seeking cosmetic surgery abroad and the most common complications, such as wound healing disorders and infection, descreased in favor of aethetic dissatisfaction, possibly indicating ameliorated patient aftercare abroad.

Enzymatic debridement for circumferential deep burns: the role of surgical escharotomy

INTRODUCTION

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.

PATIENTS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Donor Site Defect Coverage of the Forearm with Dermal Substitute After Harvesting Radial Forearm Free Flap for Phalloplasty: Is MatriDerm® Worth the Effort?

An aesthetically and functionally pleasing phalloplasty is most commonly performed by a free radial forearm flap. However, the problem with donor site morbidity on the forearm remains unsolved. The aim of this study was to evaluate if the use of a dermal template such as MatriDerm® on the donor site significantly decreases the incidence of complications based on the Clavien–Dindo classification, such as wound healing disorders and reoperation rate, and if it could shortens the duration of hospital stay. A case series analysis was conducted at our institution. A total of 21 patients divided into two groups undergoing the phallic construction after the Gottlieb and Levine design in a single center underwent the donor site defect coverage either by MatriDerm® and split-thickness skin graft from the thigh or by full-thickness skin graft from the groin area. The use of MatriDerm® and split-thickness skin graft showed to have a statistically significant impact on the rate of complications (p = 0.008). Complications that were treated conservatively as well as that require surgical revision were significantly lower in the MatriDerm® group than in the full-thickness skin graft group (p = 0.002). Complications occurred not only at the forearm but also at the groin, where the full-thickness skin graft was harvested. The large dimension of the free radial forearm flap used for phalloplasty resulted in a significant donor site morbidity, leading to wound healing disorders, reoperations, and extended length of hospital stay. Therefore, we consider the use of dermal templates such as MatriDerm® as worth the additional effort and costs in this patient collective.

Botulinum toxin to improve facial expression in a patient with Urofacial (Ochoa) Syndrome

The Urofacial or Ochoa Syndrome is a very rare congenital disorder that includes vesical bladder dysfunction and a peculiar inverse facial expression, which brings patients to express a sad-crying face while they intend to laugh. Up-to-date treatments have addressed only the urological side of this disease. However, also the impaired facial mimicry has a strong impact on patients' quality of life. We treated a young patient with Botulinum toxin to address this impairment and obtained pleasing results, including a harmonic smile and a very satisfied patient. To the best of our knowledge, this is the first time that the use of Botulinum toxin is reported in literature to address the facial expression component of this disease.

Scar versus shape: patient-reported outcome after different surgical approaches to gynecomastia measured by modified BREAST Q®

OBJECTIVES

The challenge in the operative therapy for enlargement of the male breast is to deal with the skin excess. Shape and scars are the major parameters after which patients assess their operative result. Therefore, we assessed the satisfaction rate among patients undergoing subcutaneous mastectomy at our institution with special regard to scar tissue formation and the postoperative appearance of the chest wall in dependence of the surgical approach (periarolar versus inframammary fold).

METHODS

The study includes n = 36 male patients who underwent subcutaneous mastectomy at AGAPLESION Markus Hospital Frankfurt/Main. Patient's satisfaction dependent with the appearance of the chest wall and scar formation was evaluated by a modified BREAST Q® questionnaire plus two male-based additional questions.

RESULTS

There is no statistically significant difference in satisfaction with the operative result depending on the pattern of incision (periareolar versus submammary periareolar; 81.9% versus 75.5%) with the operative result. Evaluation of additional questions of the modified BREAST Q® questionnaire showed that 86% of the patients (n = 31) would rather have more scars and a flatter chest wall. A BMI >25 kg/m² is accompanied by a higher risk for complications (p = 0.04).

CONCLUSIONS

Periareolar incision is still the method of choice, if promising an aesthetic appealing result. When reaching its limits though, we showed that a flat and male-shaped appearance of the chest wall is priority for the patients and should therefore be for the surgeon as well.

[Robotics in plastic surgery]

In recent years surgical robotic systems which were specifically developed for microsurgery have expanded the application of robotic-assisted surgery to plastic reconstructive surgery. Currently, there are two microsurgical robotic systems available for reconstructive plastic surgery. Both systems feature tremor reduction and motion scaling technologies, which are intended to optimize the surgeon's precision and dexterity. In the Department of Plastic Surgery and Hand Surgery at the University Hospital Zurich, the Symani Surgical System® has already been used for many microsurgical and supermicrosurgical operations, including autologous breast reconstruction, nerve transfer and, in particular, reconstructive lymphatic surgery. Despite special technical challenges, such as a lack of haptic feedback, the advantages outweigh the disadvantages for an appropriately trained and skilled microsurgeon, including smaller surgical access incisions for anatomically deep structures and an improvement in surgical precision.

A distinct M2 macrophage infiltrate and transcriptomic profile decisively influence adipocyte differentiation in lipedema

Lipedema is a chronic and progressive adipose tissue disorder, characterized by the painful and disproportionate increase of the subcutaneous fat in the lower and/or upper extremities. While distinct immune cell infiltration is a known hallmark of the disease, its role in the onset and development of lipedema remains unclear. To analyze the macrophage composition and involved signaling pathways, anatomically matched lipedema and control tissue samples were collected intra-operatively from gender- and BMI-matched patients, and the Stromal Vascular Fraction (SVF) was used for Cytometry by Time-of-Flight (CyTOF) and RNA sequencing. The phenotypic characterization of the immune component of lipedema versus control SVF using CyTOF revealed significantly increased numbers of CD163 macrophages. To gain further insight into this macrophage composition and molecular pathways, RNA sequencing of isolated CD11b+ cells was performed. The analysis suggested a significant modification of distinct gene ontology clusters in lipedema, including cytokine-mediated signaling activity, interleukin-1 receptor activity, extracellular matrix organization, and regulation of androgen receptor signaling. As distinct macrophage populations are known to affect adipose tissue differentiation and metabolism, we evaluated the effect of M2 to M1 macrophage polarization in lipedema using the selective PI3Kγ inhibitor IPI-549. Surprisingly, the differentiation of adipose tissue-derived stem cells with conditioned medium from IPI-549 treated SVF resulted in a significant decreased accumulation of lipids in lipedema versus control SVF. In conclusion, our results indicate that CD163+ macrophages are a critical component in lipedema and re-polarization of lipedema macrophages can normalize the differentiation of adipose-derived stem cells in vitro evaluated by the cellular lipid accumulation. These data open a new chapter in understanding lipedema pathophysiology and may indicate potential treatment options.

Targeted therapies and checkpoint inhibitors in sarcoma

Sarcomas are defined as a group of mesenchymal malignancies with over 100 heterogeneous subtypes. As a rare and difficult to diagnose entity, micrometastasis is already present at the time of diagnosis in many cases. Current treatment practice of sarcomas consists mainly of surgery, (neo)adjuvant chemo- and/or radiotherapy. Although the past decade has shown that particular genetic abnormalities can promote the development of sarcomas, such as translocations, gain-of-function mutations, amplifications or tumor suppressor gene losses, these insights have not led to established alternative treatment strategies so far. Novel therapeutic concepts with immunotherapy at its forefront have experienced some remarkable success in different solid tumors while their impact in sarcoma remains limited. In this review, the most common immunotherapy strategies in sarcomas, such as immune checkpoint inhibitors, targeted therapy and cytokine therapy are concisely discussed. The programmed cell death (PD)-1/PD-1L axis and apoptosis-inducing cytokines, such as TNF-related apoptosis-inducing ligand (TRAIL), have not yielded the same success like in other solid tumors. However, in certain sarcoma subtypes, e.g. liposarcoma or undifferentiated pleomorphic sarcoma, encouraging results in some cases when employing immune checkpoint inhibitors in combination with other treatment options were found. Moreover, newer strategies such as the targeted therapy against the ancient cytokine macrophage migration inhibitory factor (MIF) may represent an interesting approach worth investigation in the future.

Preoperative Mapping of Lymphatic Vessels by Multispectral Optoacoustic Tomography

Background: In lymphatic reconstructive surgery, visualization of lymph vessels is of paramount importance. Indocyanine green (ICG) lymphography is the current gold standard in preoperative lymphatic imaging. However, visualization of lymph vessels is often limited by an overlying dermal backflow of ICG, becoming particularly prominent in advanced lymphedema stages. Multispectral optoacoustic tomography (MSOT) has recently been introduced as a promising noninvasive tool for lymphatic imaging. Methods and Results: A single-center proof-of-concept study with a prospective observational design was conducted at the Department of Plastic Surgery and Hand Surgery of the University Hospital Zurich. Between February 2021 and August 2021, seven patients with different grades of lymphedema were analyzed by the MSOT Acuity system before undergoing lymphovenous anastomosis (LVA). Conventional ICG lymphography served as comparison. MSOT succeeded to accurately depict blood and lymphatic vessels at different locations in six patients, including areas of dermal backflow. The MSOT signal of lymph vessels further correlated well with their macroscopic appearance. Conclusion: We could successfully visualize lymphatic vessels in patients with lymphedema by MSOT and establish the new method for preoperative mapping and selection of incision sites for LVA. Regardless of dermal backflow patterns, MSOT proved to be a valuable approach for identifying and clearly discerning between lymphatic and blood vessels.

Mediators of Capillary-to-Venule Conversion in the Chronic Inflammatory Skin Disease Psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by epidermal hyperplasia and hyperkeratosis, immune cell infiltration and vascular remodeling. Despite the emerging recognition of vascular normalization as a potential strategy for managing psoriasis, an in-depth delineation of the remodeled dermal vasculature has been missing. In this study, we exploited 5' single-cell RNA sequencing to investigate the transcriptomic alterations in different subpopulations of blood vascular and lymphatic endothelial cells directly isolated from psoriatic and healthy human skin. Individual subtypes of endothelial cells underwent specific molecular repatterning associated with cell adhesion and extracellular matrix organization. Blood capillaries, in particular, showed upregulation of the melanoma cell adhesion molecule as well as its binding partners and adopted postcapillary venule‒like characteristics during chronic inflammation that are more permissive to leukocyte transmigration. We also identified psoriasis-specific interactions between cis-regulatory enhancers and promoters for each endothelial cell subtype, revealing the dysregulated gene regulatory networks in psoriasis. Together, our results provide more insights into the specific transcriptional responses and epigenetic signatures of endothelial cells lining different vessel compartments in chronic skin inflammation.

Is Lymphedema a Systemic Disease? A Paired Molecular and Histological Analysis of the Affected and Unaffected Tissue in Lymphedema Patients

Secondary lymphedema is a chronic, debilitating disease and one of the most common side effects of oncologic surgery, substantially decreasing quality of life. Despite the progress conducted in lymphedema research, the underlying pathomechanisms remain elusive. Lymphedema is considered to be a disease affecting an isolated extremity, yet imaging studies suggest systemic changes of the lymphatic system in the affected patients. To evaluate potential systemic manifestations in lymphedema, we collected matched fat and skin tissue from the edematous and non-edematous side of the same 10 lymphedema patients as well as anatomically matched probes from control patients to evaluate whether known lymphedema manifestations are present systemically and in comparison to health controls. The lymphedematous tissue displayed various known hallmarks of lymphedema compared to the healthy controls, such as increased epidermis thickness, collagen deposition in the periadipocyte space and the distinct infiltration of CD4+ cells. Furthermore, morphological changes in the lymphatic vasculature between the affected and unaffected limb in the same lymphedema patient were visible. Surprisingly, an increased collagen deposition as well as CD4 expression were also detectable in the non-lymphedematous tissue of lymphedema patients, suggesting that lymphedema may trigger systemic changes beyond the affected extremity.

Novel Blood Vascular Endothelial Subtype-Specific Markers in Human Skin Unearthed by Single-Cell Transcriptomic Profiling

Ample evidence pinpoints the phenotypic diversity of blood vessels (BVs) and site-specific functions of their lining endothelial cells (ECs). We harnessed single-cell RNA sequencing (scRNA-seq) to dissect the molecular heterogeneity of blood vascular endothelial cells (BECs) in healthy adult human skin and identified six different subpopulations, signifying arterioles, post-arterial capillaries, pre-venular capillaries, post-capillary venules, venules and collecting venules. Individual BEC subtypes exhibited distinctive transcriptomic landscapes associated with diverse biological pathways. These functionally distinct dermal BV segments were characterized by their unique compositions of conventional and novel markers (e.g., arteriole marker GJA5; arteriole capillary markers ASS1 and S100A4; pre-venular capillary markers SOX17 and PLAUR; venular markers EGR2 and LRG1), many of which have been implicated in vascular remodeling upon inflammatory responses. Immunofluorescence staining of human skin sections and whole-mount skin blocks confirmed the discrete expression of these markers along the blood vascular tree in situ, further corroborating BEC heterogeneity in human skin. Overall, our study molecularly refines individual BV compartments, whilst the identification of novel subtype-specific signatures provides more insights for future studies dissecting the responses of distinct vessel segments under pathological conditions.

Patient-Reported Outcomes in Free-Flap Breast Reconstructive Surgery over Time (PRO-BREST)

<b><i>Introduction:</i></b> Patient-reported outcomes (PROMs) are increasingly relevant to assess surgical quality and guide decisions in breast reconstruction (BR). Satisfaction with outcomes may change as time progresses. We assessed satisfaction in patients who underwent free-flap BR in the last 12 years. <b><i>Methods:</i></b> All patients who underwent free-flap BR from 2006 to 2018 were invited to complete the validated BREAST-Q for reconstruction. The BREAST-Q comprises 6 domains covering various aspects of satisfaction. Unadjusted linear regression assessed the relationship between different domains of the BREAST-Q and time since BR. Two-sample <i>t</i> tests assessed differences in satisfaction between patients who underwent BR ≥5 years versus &#x3c;5 years prior. <b><i>Results:</i></b> Forty-three women with primary or secondary free-flap BR between 2006 and 2018 were included in the study. Most patients (<i>n</i> = 33, 76.7%) underwent DIEP flap BR. Overall satisfaction with breasts and with outcomes improved as time since BR increased (<i>p</i> = 0.031 and <i>p</i> = 0.017, respectively). Overall satisfaction with outcomes scored higher in patients with BR ≥5 years prior (≥5 years vs. &#x3c;5 years: breast score 88.6 (SD 12.5) versus 66.9 (SD 21.8); <i>p</i> = 0.005). Satisfaction with breasts and psychosocial well-being also scored higher in these patients. There was no difference in results between primary and secondary BR. Patients who underwent additional surgery (refinements) reported higher satisfaction with outcomes and abdominal well-being. <b><i>Conclusions:</i></b> PROMs concerning satisfaction with breast and with outcomes following BR improve as time since treatment progresses. This study demonstrates that time since diagnosis may be an important factor in satisfaction. It underlines the importance of long-term PROMs related to BR, to help provide patients and health care professionals in decision-making and in managing expectations related to BR.

Development and Clinical Validation of the LymphMonitor Technology to Quantitatively Assess Lymphatic Function

Current diagnostic methods for evaluating the functionality of the lymphatic vascular system usually do not provide quantitative data and suffer from many limitations including high costs, complexity, and the need to perform them in hospital settings. In this work, we present a quantitative, simple outpatient technology named LymphMonitor to quantitatively assess lymphatic function. This method is based on the painless injection of the lymphatic-specific near-infrared fluorescent tracer indocyanine green complexed with human serum albumin, using MicronJet600^TM microneedles, and monitoring the disappearance of the fluorescence signal at the injection site over time using a portable detection device named LymphMeter. This technology was investigated in 10 patients with unilateral leg or arm lymphedema. After injection of a tracer solution into each limb, the signal was measured over 3 h and the area under the normalized clearance curve was calculated to quantify the lymphatic function. A statistically significant difference in lymphatic clearance in the healthy versus the lymphedema extremities was found, based on the obtained area under curves of the normalized clearance curves. This study provides the first evidence that the LymphMonitor technology has the potential to diagnose and monitor the lymphatic function in patients.

The Role of Macrophage Migration Inhibitory Factor in Adipose-Derived Stem Cells Under Hypoxia

Background: Adipose-derived stem cells (ASCs) are multipotent mesenchymal stem cells characterized by their strong regenerative potential and low oxygen consumption. Macrophage migration inhibitory factor (MIF) is a multifunctional chemokine-like cytokine that is involved in tissue hypoxia. MIF is not only a major immunomodulator but also is highly expressed in adipose tissue such as subcutaneous adipose tissue of chronic non-healing wounds. In the present study, we investigated the effect of hypoxia on MIF in ASCs isolated from healthy versus inflamed adipose tissue. Methods: Human ASCs were harvested from 17 patients (11 healthy adipose tissue samples, six specimens from chronic non-healing wounds). ASCs were treated in a hypoxia chamber at <1% oxygen. ASC viability, MIF secretion as well as expression levels of MIF, its receptor CD74, hypoxia-inducible transcription factor-1α (HIF-1α) and activation of the AKT and ERK signaling pathways were analyzed. The effect of recombinant MIF on the viability of ASCs was determined. Finally, the effect of MIF on the viability and production capacity of ASCs to produce the inflammatory cytokines tumor necrosis factor (TNF), interleukin (IL)-6, and IL-1β was determined upon treatment with recombinant MIF and/or a blocking MIF antibody. Results: Hypoxic treatment inhibited proliferation of ASCs derived from healthy or chronic non-healing wounds. ASCs from healthy adipose tissue samples were characterized by a low degree of MIF secretion during hypoxic challenge. In contrast, in ASCs from adipose tissue samples of chronic non-healing wounds, secretion and expression of MIF and CD74 expression were significantly elevated under hypoxia. This was accompanied by enhanced ERK signaling, while AKT signaling was not altered. Recombinant MIF did stimulate HIF-1α expression under hypoxia as well as AKT and ERK phosphorylation, while no effect on ASC viability was observed. Recombinant MIF significantly reduced the secretion of IL-1β under hypoxia and normoxia, and neutralizing MIF-antibodies diminished TNF-α and IL-1β release in hypoxic ASCs. Conclusions: Collectively, MIF did not affect the viability of ASCs from neither healthy donor site nor chronic wounds. Our results, however, suggest that MIF has an impact on the wound environment by modulating inflammatory factors such as IL-1β.

Insurance coverage policies for reconstructive lymphatic microsurgery procedures in Switzerland

BACKGROUND

Lymphoedema is a progressive and potentially disabling disease. A growing number of studies show promising clinical results after microsurgical reconstruction. However, this treatment is currently not supported by level 1 evidence and insurance coverage is variable.

METHODS

Electronic records of 55 patients with limb lymphoedema, who were eligible for lymphovenous bypass surgery and/or lymphatic tissue transfer in our department from 2017 to 2020, were reviewed. Correspondence between our department and health insurers was analysed. A web-based search and individual telephone interviews were conducted to identify health insurer policies.

RESULTS

We included 42 patients undergoing 46 operations and evaluated the correspondence between our department and nine different health insurers. Overall, reimbursement of costs was approved in 67% (n = 31) of all surgeries and was refused in 33% (n = 15). The mean number of applications for reconsideration sent to insurers was 1.3 &plusmn; 0.7. The time between confirmation of the indication and the final decision ranged from 6 to 300 days (mean 50 days). Reimbursement of cost coverage ranged from 0% to 100% depending on the individual insurance company. No insurance company had policies publicly available online and all stated that they determine coverage only when provided with specific patient details on a case-by-case basis.

CONCLUSION

Insurance companies in Switzerland do not have a uniform policy regarding cost coverage for lymphatic surgery procedures. Moreover, the decision process appeared to be rather uniform within the respective insurance company and independent of the individual case. Standardised evaluation criteria including patient reported outcome measures should be developed to underscore the beneficial effects of lymphatic surgery and facilitate insurance coverage.

YouTube as a resource for surgical education with a focus on plastic surgery - a systematic review

Surgery trainees use videos as a means to learn about surgical procedures. YouTube is the biggest online video platform and used for educational content as well but the medical information provided does not undergo peer review or other forms of scientific screening and can thus be of poorer quality. We performed a systematic review that examined the quality of educational videos about surgery and plastic surgery in particular on YouTube. The focus was towards studies on the benefit of YouTube videos for surgical trainees. A literature review was performed to determine the educational quality of plastic surgery videos found on YouTube. Articles reviewing the educational quality of videos about surgical procedures, their accuracy, and their utility for surgical trainees were included. An additional review was performed evaluating the literature about the quality of educational plastic surgery videos. Eleven articles were selected reviewing the educational quality of videos about surgical procedures. Six studies were fully assessed and evaluated concerning the quality of educational plastic surgery videos. There currently seems to be a lack of comprehensive educational surgery and in particular plastic surgery-related information on YouTube. The popularity of YouTube among surgical trainees is high. The quality of available educational surgical video content varies widely. It is in the interest of plastic surgery teaching institutions to provide trainees with high-quality educational video material.

'Viewer discretion advised when preparing for surgery' - why YouTube cannot teach you how to do an upper blepharoplasty. An evaluation of the educational potential of surgical videos on blepharoplasty on YouTube

Over the last years, the layout of surgical training has significantly changed. Surgical residents rely on YouTube videos to prepare for upcoming cases. Eyelid surgery including blepharoplasty ranks among the 5 most often performed cosmetic surgeries. It will be one of those surgeries regularly researched by plastic surgery residents. Therefore, the aim of this study was to evaluate the educational value of the most viewed upper lid blepharoplasty videos on the most popular video broadcasting website, YouTube. A video scoring system consisting of 8 items was developed in accordance with the technical details described in the literature. Video scores were categorized into 3 groups, namely as 'poor', 'moderate; or 'good' in terms of their contribution to surgical education. The first 300 videos were evaluated for the search results for 'blepharoplasty'. After exclusion and summarization of video fragments, a total number of 36 videos were included in the study. Multivariable logistic regression models found no correlation between likes, views, comments and the attributed educational score. The quality of available educational surgical video content varies widely, and surgical trainees need to be critically aware of this as view counts as well as the number of likes and comments will not necessarily relate to videos' educational quality. There is a need for high-quality educational videos.

Short-term molecular and cellular effects of ischemia/reperfusion on vascularized lymph node flaps in rats

Vascularized lymph node (VLN) transfer is an emerging strategy to re-establish lymphatic drainage in chronic lymphedema. However, the biological processes underlying lymph node integration remain elusive. This study introduces an experimental approach facilitating the analysis of short-term molecular and cellular effects of ischemia/reperfusion on VLN flaps. Lymph node flaps were dissected pedicled on the lateral thoracic vessels in 44 Lewis rats. VLN flaps were exposed to 45 or 120 minutes ischemia by in situ clamping of the vascular pedicle with subsequent reperfusion for 24 hours. Flaps not exposed to ischemia/reperfusion served as controls. Lymph nodes and the perinodal adipose tissue were separately analyzed by Western blot for the expression of lymphangiogenic and angiogenic growth factors. Moreover, morphology, microvessel density, proliferation, apoptosis and immune cell infiltration of VLN flaps were further assessed by histology and immunohistochemistry. Ischemia for 120 minutes was associated with a markedly reduced cellularity of lymph nodes but not of the perinodal adipose tissue. In line with this, ischemic lymph nodes exhibited a significantly lower microvessel density and an increased expression of VEGF-D and VEGF-A. However, VEGF-C expression was not upregulated. In contrast, analyses of the perinodal adipose tissue revealed a more subtle decrease of microvessel density, while only the expression of VEGF-D was increased. Moreover, after 120 minutes ischemia, lymph nodes but not the perinodal adipose tissue exhibited significantly higher numbers of proliferating and apoptotic cells as well as infiltrated macrophages and neutrophilic granulocytes compared with non-ischemic flaps. Taken together, lymph nodes of VLN flaps are highly susceptible to ischemia/reperfusion injury. In contrast, the perinodal adipose tissue is less prone to ischemia/reperfusion injury.

[Presence of hand surgery in social media]

BACKGROUND

Social media play an important role in everyday life including medical professional life. Societies like the Federation of European Societies for Surgery of the Hand (FESSH) are acknowledging social media's importance by establishing designated social media committees. No recent publication exists on the use of social media in and for hand surgery.

PURPOSE

The aim of this study was to analyse the current use of social media in and for hand surgery with respect on Instagram.

MATERIAL AND METHODS

The 100 top-posts published on Instagram in July 2019 using the hashtags #handsurgery, #handsurgeon and #fessh were analysed regarding the author, the topic and kind of the post, the likes and comments on the post.

RESULTS

101 of the 300 posts were posted by hand surgeons. The majority of posts (172 = 57.3 %) were self-promoting posts; 41 were for medical education. 199 (66.3 %) posts included 1 photo, 63 (21.0 %) two or more photos, and 38 (12.7 %) posts included a video. Video-posts and posts by hand therapists had the most likes and comments.

CONCLUSION

In hand surgery social media is used for self-promotions, but also for medical education. Video-posts are the preferred posts.

Surgical management of isolated orbital floor and zygomaticomaxillary complex fractures with focus on surgical approaches and complications

Zygomaticomaxillary complex (ZMC) and orbital blow out fractures are commonly encountered midfacial fractures that may result in aesthetic and functional impairment. This retrospective study reports on the surgical treatment and associated postoperative complications in our patient collective. We evaluated 100 patients who underwent open reduction and internal fixation of midfacial fractures between 2010 and 2015. Preoperative clinical features, surgical technique and postoperative complications were analyzed. Surgery was performed with a mean latency of 7 days after trauma. We used titanium mesh and polydioxanone sheets to reconstruct the orbital floor. Most ZMC fractures were stabilized with two point fixation with titanium plates. Preoperative symptoms were present in 70 patients (70%). Infraorbital hypesthesia occurred in 49 patients, diplopia in 41 patients and ocular motility impairment in 24 patients. Postoperative symptoms persisted during a mean follow-up time of 4.5 months in 47 patients (47%) showing infraorbital hypesthesia in 24%, diplopia in 17%, ectropion in 7% and ocular motility impairment in 4%. Complications requiring revision were retrobulbar hematoma 3% (n = 3), ectropion 3% (n = 3), diplopia 1% (n = 1), exophthalmos 1% (n = 1), implant dislocation 1% (n = 1), implant discomfort 2% (n = 2), persisting fracture dislocation 1% (n = 1). All patients recovered without significant impairment. Surgery is required in the majority of the patients with midfacial fractures. Among others ectropion is challenging due to its aesthetic and functional impact on patients. To prevent ectropion, additional canthopexy or the transconjunctival surgical approach are reasonable options in selected cases. Level of Evidence: Level V, descriptive study. AbbreviationsCTcomputed tomographyOForbital floorPDSpolydioxanoneORIFopen reduction and internal fixationZMCzygomaticomaxillary complex.

Finger reconstruction with dorsal metacarpal artery perforator flaps and dorsal finger perforator flaps based on the dorsal branches of the palmar digital arteries - 40 consecutive cases

Since the first description many variations of the dorsal metacarpal reverse island flap have been published but there is still uncertainty about which vascular component should be included for an optimal result. Therefore, it was the aim of this study to analyze vascular reliability and ischemic complications of dorsal metacarpal artery perforator (DMAP) flaps and dorsal finger perforator (DFP) flaps in our patient collective. We performed 40 of these flaps from the dorsum of hand and fingers for finger injuries. The choice of donor site was made according to the defect's location. Patients were analyzed with respect to flap necrosis, ischemic complications and achievement of overall reconstruction goals. In addition, we divided our patients in two groups, one group where we raised the flap from the dorsum of the proximal phalanx and a second one where the flaps were raised from the intermetacarpal space to identify complication rates based on the pedicles location. Of the 40 flaps, 36 survived completely. 4 partial necroses were observed in flaps transferred to more distal defects and in one flap that was used in a wrap-around technique for both dorsal and palmar proximal phalanx. These perforator flaps are a reliable method to cover finger defects and the dorsal metacarpal artery is not necessary for their survival, since the blood supply comes from perforating branches of the palmar vascular system. There is a clear trend for a higher complication rate in flaps raised from the dorsum of the fingers compared to the intermetacarpal space.

Adipose tissue and the vascularization of biomaterials: Stem cells, microvascular fragments and nanofat-a review

Tissue defects in the human body after trauma and injury require precise reconstruction to regain function. Hence, there is a great demand for clinically translatable approaches with materials that are both biocompatible and biodegradable. They should also be able to adequately integrate within the tissue through sufficient vascularization. Adipose tissue is abundant and easily accessible. It is a valuable tissue source in regenerative medicine and tissue engineering, especially with regard to its angiogenic potential. Derivatives of adipose tissue, such as microfat, nanofat, microvascular fragments, stromal vascular fraction and stem cells, are commonly used in research, but also clinically to enhance the vascularization of implants and grafts at defect sites. In plastic surgery, adipose tissue is harvested via liposuction and can be manipulated in three ways (macro-, micro- and nanofat) in the operating room, depending on its ultimate use. Whereas macro- and microfat are used as a filling material for soft tissue injuries, nanofat is an injectable viscous extract that primarily induces tissue remodeling because it is rich in growth factors and stem cells. In contrast to microfat that adds volume to a defect site, nanofat has the potential to be easily combined with scaffold materials due to its liquid and homogenous consistency and is particularly attractive for blood vessel formation. The same is true for microvascular fragments that are easily isolated from adipose tissue through collagenase digestion. In preclinical animal models, it has been convincingly shown that these vascular fragments inosculate with host vessels and subsequently accelerate scaffold perfusion and host tissue integration. Adipose tissue is also an ideal source of stem cells. It yields larger quantities of cells than any other source and is easier to access for both the patient and doctor compared with other sources such as bone marrow. They are often used for tissue regeneration in combination with biomaterials. Adipose-derived stem cells can be applied unmodified or as single cell suspensions. However, certain pretreatments, such as cultivation under hypoxic conditions or three-dimensional spheroids production, may provide substantial benefit with regard to subsequent vascularization in vivo due to induced growth factor production. In this narrative review, derivatives of adipose tissue and the vascularization of biomaterials are addressed in a comprehensive approach, including several sizes of derivatives, such as whole fat flaps for soft tissue engineering, nanofat or stem cells, their secretome and exosomes. Taken together, it can be concluded that adipose tissue and its fractions down to the molecular level promote, enhance and support vascularization of biomaterials. Therefore, there is a high potential of the individual fat component to be used in regenerative medicine.

Adipose Tissue Hypertrophy, An Aberrant Biochemical Profile and Distinct Gene Expression in Lipedema

BACKGROUND

Lipedema is a common adipose tissue disorder affecting women, characterized by a symmetric subcutaneous adipose tissue deposition, particularly of the lower extremities. Lipedema is usually underdiagnosed, thus remaining an undertreated disease. Importantly, no histopathologic or molecular hallmarks exist to clearly diagnose the disease, which is often misinterpreted as obesity or lymphedema.

MATERIALS AND METHODS

The aim of the present study is to characterize in detail morphologic and molecular alterations in the adipose tissue composition of lipedema patients compared with healthy controls. Detailed histopathologic and molecular characterization was performed using lipid and cytokine quantification as well as gene expression arrays. The analysis was conducted on anatomically matched skin and fat tissue biopsies as well as fasting serum probes obtained from 10 lipedema and 11 gender and body mass index-matched control patients.

RESULTS

Histologic evaluation of the adipose tissue showed increased intercellular fibrosis and adipocyte hypertrophy. Serum analysis showed an aberrant lipid metabolism without changes in the circulating adipokines. In an adipogenesis gene array, a distinct gene expression profile associated with macrophages was observed. Histologic assessment of the immune cell infiltrate confirmed the increased presence of macrophages, without changes in the T-cell compartment.

CONCLUSIONS

Lipedema presents a distinguishable disease with typical tissue architecture and aberrant lipid metabolism, different to obesity or lymphedema. The differentially expressed genes and immune cell infiltration profile in lipedema patients further support these findings.

Lipoconstruct surface topography grating size influences vascularization onset in the dorsal skinfold chamber model

After skin tissue injury or pathological removal, vascularization timing is paramount in graft survival. As full thickness skin grafts often fail to become perfused over larger surfaces, split-thickness grafts are preferred and can be used together with biomaterials, which themselves are non-angiogenic. One way of promoting vascular ingrowth is to "pre-vascularize" an engineered substitute by introducing endothelial cells (ECs). Since it has been previously demonstrated that surface structured biomaterials have an effect on wound healing, skin regeneration, and fibrosis reduction, we proposed that a microvascular-rich lipoconstruct with anisotropic topographical cues could be a clinically translatable vascularization approach. Murine lipofragments were formed with three polydimethylsiloxane molds (flat, 5 µm, and 50 µm parallel gratings) and implanted into the dorsal skinfold chamber of male C57BL/6 mice. Vascular ingrowth was observed through intravital microscopy over 21 days and further assessed by histology and protein identification. Our investigation revealed that topographical feature size influenced the commencement of neovascular ingrowth, with 5 µm gratings exhibiting early construct perfusion at 3 days post-operation, and 50 µm being delayed until day 5. We therefore postulate that surface structured lipoconstructs may serve as an easily obtained and produced construct suitable for providing soft tissue and ECs to tissue defects. STATEMENT OF SIGNIFICANCE: Skin graft failures due to inadequate or uneven perfusion frequently occur and can be even more complicated in deep, difficult to heal wounds, or bone coverage. In complex injuries, biomaterials are often used to cover bone structures with a standard split thickness graft; however, perfusion can take up to 3 weeks. Thus, any means to promote faster and uniform vascularization could significantly reduce healing time, as well as lower patient down-time. As pre-vascularized constructs have reported success in research, we created a cost-efficient, translatable method with no additional laboratory time as adipose tissue can be harvested and used immediately. We further used surface topography as an aspect to modulate construct perfusion, which has been reported for the first time here.

Lymphovenous Anastomosis for the Treatment of Thoracic Duct Lesion: A Case Report and Systematic Review of Literature

BACKGROUND

Chylous leak is an uncommon complication after head and neck surgery and typically results from a lesion of the thoracic duct (TD). Beside conservative treatment, different minimally invasive and surgical procedures exist, of which almost all lead to a total closure of the TD.

METHODS

We report on a rare case of microsurgical lymphovenous anastomosis to treat a TD lesion. An additional systematic review on surgical procedures to treat TD lesions with special attention to lymphovenous anastomoses was performed according to the PRISMA guidelines.

RESULTS

A 52-year-old patient with a chylous fistula after modified radical neck dissection was successfully treated by a lymphovenous anastomosis of the TD and external jugular vein with additional coverage by sternocleidomastoid muscle flap. The patient showed a complete resolution of chylous leak with an uneventful postoperative course.The systematic search of literature yielded 684 articles with 4 case reports on lymphovenous anastomosis in chylous leak with a high success rate. Other surgical techniques include transcervical, thoracoscopic, or video-assisted thoracoscopic TD ligation, either alone or combined with a local muscle flap.

CONCLUSIONS

Lymphovenous anastomosis of the TD is a feasible and safe technique allowing for treatment of cervical TD lesions, especially if minimally invasive procedures fail. Compared with other techniques, lymphatic circulation can successfully be maintained.

Progressive Disease in Sentinel-negative Melanoma Patients: Biological Differences and Importance of Sentinel Lymph Node Biopsy

BACKGROUND/AIM

Among the most important prognostic factors in melanoma is the sentinel lymph node (SLN) status.

MATERIALS AND METHODS

Using our electronic database we identified 109 of 890 SLN-negative patients with progressive disease (PD). These patients were characterized for melanoma type, molecular type, sequence and extent of metastatic spread.

RESULTS

A total of 61 of 109 SLN-negative patients had PD in the SLN-basin indicating false-negative SLN (group-1). Forty eight of 109 patients had PD at distant sites and were therefore impossible to be identified using SLN biopsy (group-2). Despite distant spread these patients had significantly more single organ metastasis (p<0.001) and significantly longer disease-free-survival (p=0.001) compared to group-1. Additionally, to significant differences on a molecular basis between the two groups (p=0.01), all lentigo maligna and spindle-cell-melanomas belonged to group-2 and all, except one lentigo maligna melanoma, had single visceral metastasis.

CONCLUSION

Two different biological groups among SLN-negative patients with PD were demonstrated. Extravascular-migratory-metastasis, rather than hematogenous spread, might be responsible for the observed PD with single organ involvement.