Sentinel Lymph Node Detection in Cutaneous Melanoma Using Indocyanine Green-Based Near-Infrared Fluorescence Imaging: A Systematic Review and Meta-Analysis.

The standard of care approach to identify sentinel lymph nodes (SLNs) in clinically non-metastatic cutaneous melanoma patients is technetium (Tc)-based lymphoscintigraphy. This technique is associated with radiation exposure, a long intervention time, high costs, and limited availability. Indocyanine green (ICG)-based near-infrared fluorescence imaging offers a potential alternative if proven to be of comparable diagnostic accuracy. While several clinical cohorts have compared these modalities, no systematic review exists that provides a quantitative analysis of their results. Hence, a systematic literature review was conducted in December 2023 considering clinical studies comparing the diagnostic accuracy of ICG and Tc for sentinel lymph node biopsy in cutaneous melanoma patients. Three hundred nineteen studies were identified and further screened in accordance with the PRISMA 2020 guidelines, resulting in seven studies being included in the final meta-analysis. Tc identified a significantly higher number of SLNs and metastatic SLNs in prospective studies only. However, in the overall meta-analysis of all included comparative studies, no significant differences were found regarding the identification of metastatic patients or the false negative rate (FNR). ICG may be a non-inferior alternative to Tc for intraoperative guidance in sentinel lymph node biopsy in cutaneous melanoma patients. Future randomized controlled trials are needed, especially regarding the preoperative, transcutaneous identification of the affected lymph node basin

Post-bariatric contour deformity correction: an endeavour to establish objective criteria nationally.

BACKGROUND A marked increase in bariatric surgery has led to higher numbers of patients with contour deformities after massive weight loss seeking plastic surgical correction. Insurance coverage for these post-bariatric interventions is highly subjective and a common set of objective criteria has not yet been established. AIM The aim was to evaluate the factors influencing insurance coverage for post-bariatric surgery, focusing on finding objective, reproducible criteria. METHODS This was a retrospective single centre chart review of all post-bariatric patients with redundant skin requesting body contouring surgery from 2013 to 2018. Demographic, bariatric and surgical, as well as insurance information were collected. A logistic regression model was used to identify predictors of successful insurance coverage. RESULTS 116 Patients were included in the study. Insurance approval for post-bariatric body contouring surgery was obtained for only 47 patients (41%). Mentioning the term "medical indication" in the application letter was associated with a 15.2 times higher rate of receiving a positive answer (p <0.001), whereas mentioning "mental suffering" was associated with 82.3% lower chance of getting a positive response (p <0.001). A high body mass index (BMI) (p <0.009) before the bariatric operation as well as a high BMI reduction (p <0.021) were associated with a higher approval rate by insurance companies . An additional application letter to the insurance company (p <0.024) as well as mentioning mechanical restriction (p <0.022) were associated with a positive response from the insurance companies. CONCLUSIONS We were able to establish certain objective predictive criteria for insurance coverage of post-bariatric surgery. However, it appears that the decisions of insurance companies for this condition are still rather randomly taken. Therefore, the establishment of objective criteria for insurance coverage may allow fairer treatment for this growing patient population

Management of Postoperative Seroma: Recommendations Based on a 12-Year Retrospective Study.

INTRODUCTION Seroma formation is a serious postoperative complication. Since the management algorithms available in the literature are scarce, we aimed to analyze our experience with postoperative seroma in order to identify indicators for revisional surgery and propose recommendations for management. METHODS This retrospective study included all patients with postoperative seroma treated in a tertiary university hospital from 2008 to 2020. Patients' demographics, medical history, and seroma treatment details were recorded and analyzed. RESULTS Overall, 156 patients were included: 41% were initially treated through needle aspiration, with 61% eventually undergoing surgical treatment for postoperative seroma. Comorbidities, such as heart failure and coronary heart disease, were significantly associated with an increased need for revisional surgery (p &lt; 0.05). Both a duration of &gt;40 days of repeated needle aspirations and drain re-insertions were significantly correlated with an increased risk for revisional surgery (p &lt; 0.05). CONCLUSION Patients requiring seroma aspiration should be counseled on surgical treatment sooner rather than later, as prolonged aspiration time (over 40 days) greatly increases the risk of surgical revision. Moreover, the reinsertion of a drain should only be used as a temporizing measure, at most, and patients requiring a drain to control the size of the seroma should promptly be scheduled for a surgical revision

Transcutaneous sentinel lymph node detection in cutaneous melanoma with indocyanine green and near-infrared fluorescence: A diagnostic sensitivity study.

Sentinel lymph node (SLN) biopsy with preoperative radiocolloid-based lymphoscintigraphy and blue dye injection is considered the standard procedure for staging nodal metastases in early-stage cutaneous melanoma patients with clinically uninvolved lymph nodes. While this combination renders good accuracy in SLN detection, radiation exposure and the frequent allergic reactions to the blue dye are considered drawbacks of this technique. Indocyanine green (ICG) is a water-soluble fluorescent dye that can be identified through near-infrared fluorescence imaging (NIRFI). The aim of this prospective diagnostic sensitivity study was to assess the feasibility of ICG and NIRFI to identify SLNs in melanoma transcutaneously ("before skin incision") and to analyze the various factors influencing detection rate, in comparison to lymphoscintigraphy. This study included 93 patients undergoing SLN biopsy for cutaneous melanoma. The region and the number of the SLNs identified with lymphoscintigraphy and with ICG were recorded. Patients' characteristics, as well as tumor details were also recorded preoperatively. One hundred and ninety-four SLNs were identified through lymphoscintigraphy. The sensitivity of ICG for transcutaneous identification of the location of the SLNs was 96.1% overall, while the sensitivity rate for the number of SLNs was 79.4%. Gender and age did not seem to influence detection rate, but a body mass index >30 kg/m2 was associated with a lower identification rate of the number of SLNs (P = .045). Transcutaneous identification of SLNs through ICG and NIRFI technology is a feasible technique that could potentially replace in selected patients the standard SLN detection methodology in cutaneous melanoma

Transcriptome profiling of immune rejection mechanisms in a porcine vascularized composite allotransplantation model

BackgroundVascularized composite allotransplantation (VCA) offers the potential for a biological, functional reconstruction in individuals with limb loss or facial disfigurement. Yet, it faces substantial challenges due to heightened immune rejection rates compared to solid organ transplants. A deep understanding of the genetic and immunological drivers of VCA rejection is essential to improve VCA outcomesMethodsHeterotopic porcine hindlimb VCA models were established and followed until reaching the endpoint. Skin and muscle samples were obtained from VCA transplant recipient pigs for histological assessments and RNA sequencing analysis. The rejection groups included recipients with moderate pathological rejection, treated locally with tacrolimus encapsulated in triglycerol-monostearate gel (TGMS-TAC), as well as recipients with severe end-stage rejection presenting evident necrosis. Healthy donor tissue served as controls. Bioinformatics analysis, immunofluorescence, and electron microscopy were utilized to examine gene expression patterns and the expression of immune response markers.ResultsOur comprehensive analyses encompassed differentially expressed genes, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes pathways, spanning various composite tissues including skin and muscle, in comparison to the healthy control group. The analysis revealed a consistency and reproducibility in alignment with the pathological rejection grading. Genes and pathways associated with innate immunity, notably pattern recognition receptors (PRRs), damage-associated molecular patterns (DAMPs), and antigen processing and presentation pathways, exhibited upregulation in the VCA rejection groups compared to the healthy controls. Our investigation identified significant shifts in gene expression related to cytokines, chemokines, complement pathways, and diverse immune cell types, with CD8 T cells and macrophages notably enriched in the VCA rejection tissues. Mechanisms of cell death, such as apoptosis, necroptosis and ferroptosis were observed and coexisted in rejected tissues.ConclusionOur study provides insights into the genetic profile of tissue rejection in the porcine VCA model. We comprehensively analyze the molecular landscape of immune rejection mechanisms, from innate immunity activation to critical stages such as antigen recognition, cytotoxic rejection, and cell death. This research advances our understanding of graft rejection mechanisms and offers potential for improving diagnostic and therapeutic strategies to enhance the long-term success of VCA

Bioactive nanoparticle-based formulations increase survival area of perforator flaps in a rat model.

BACKGROUND Distal flap necrosis is a frequent complication of perforator flaps. Advances in nanotechnology offer exciting new therapeutic approaches. Anti-inflammatory and neo-angiogenic properties of certain metal oxides within the nanoparticles, including bioglass and ceria, may promote flap survival. Here, we explore the ability of various nanoparticle formulations to increase flap survival in a rat model. MATERIALS AND METHODS A 9 x 3 cm dorsal flap based on the posterior thigh perforator was raised in 32 Lewis rats. They were divided in 4 groups and treated with different nanoparticle suspensions: I-saline (control), II-Bioglass, III-Bioglass/ceria and IV-Zinc-doped strontium-substituted bioglass/ceria. On post-operative day 7, planimetry and laser Doppler analysis were performed to assess flap survival and various samples were collected to investigate angiogenesis, inflammation and toxicity. RESULTS All nanoparticle-treated groups showed a larger flap survival area as compared to the control group (69.9%), with groups IV (77,3%) and II (76%) achieving statistical significance. Blood flow measurements by laser Doppler analysis showed higher perfusion in the nanoparticle-treated flaps. Tissue analysis revealed higher number of blood vessels and increased VEGF expression in groups II and III. The cytokines CD31 and MCP-1 were decreased in groups II and IV. CONCLUSIONS Bioglass-based nanoparticles exert local anti-inflammatory and neo-angiogenic effects on the distal part of a perforator flap, increasing therefore its survival. Substitutions in the bioglass matrix and trace metal doping allow for further tuning of regenerative activity. These results showcase the potential utility of these nanoparticles in the clinical setting

Protein Aggregation on Metal Oxides Governs Catalytic Activity and Cellular Uptake.

Engineering of catalytically active inorganic nanomaterials holds promising prospects for biomedicine. Catalytically active metal oxides show applications in enhancing wound healing but have also been employed to induce cell death in photodynamic or radiation therapy. Upon introduction into a biological system, nanomaterials are exposed to complex fluids, causing interaction and adsorption of ions and proteins. While protein corona formation on nanomaterials is acknowledged, its modulation of nanomaterial catalytic efficacy is less understood. In this study, proteomic analyses and nano-analytic methodologies quantify and characterize adsorbed proteins, correlating this protein layer with metal oxide catalytic activity in vitro and in vivo. The protein corona comprises up to 280 different proteins, constituting up to 38% by weight. Enhanced complement factors and other opsonins on nanocatalyst surfaces lead to their uptake into macrophages when applied topically, localizing >99% of the nanomaterials in tissue-resident macrophages. Initially, the formation of the protein corona significantly reduces the nanocatalysts' activity, but this activity can be partially recovered in endosomal conditions due to the proteolytic degradation of the corona. Overall, the research reveals the complex relationship between physisorbed proteins and the catalytic characteristics of specific metal oxide nanoparticles, providing design parameters for optimizing nanocatalysts in complex biological environments

A local drug delivery system prolongs graft survival by dampening T cell infiltration and neutrophil extracellular trap formation in vascularized composite allografts.

INTRODUCTION The standard treatment for preventing rejection in vascularized composite allotransplantation (VCA) currently relies on systemic immunosuppression, which exposes the host to well-known side effects. Locally administered immunosuppression strategies have shown promising results to bypass this hurdle. Nevertheless, their progress has been slow, partially attributed to a limited understanding of the essential mechanisms underlying graft rejection. Recent discoveries highlight the crucial involvement of innate immune components, such as neutrophil extracellular traps (NETs), in organ transplantation. Here we aimed to prolong graft survival through a tacrolimus-based drug delivery system and to understand the role of NETs in VCA graft rejection. METHODS To prevent off-target toxicity and promote graft survival, we tested a locally administered tacrolimus-loaded on-demand drug delivery system (TGMS-TAC) in a multiple MHC-mismatched porcine VCA model. Off-target toxicity was assessed in tissue and blood. Graft rejection was evaluated macroscopically while the complement system, T cells, neutrophils and NETs were analyzed in graft tissues by immunofluorescence and/or western blot. Plasmatic levels of inflammatory cytokines were measured using a Luminex magnetic-bead porcine panel, and NETs were measured in plasma and tissue using DNA-MPO ELISA. Lastly, to evaluate the effect of tacrolimus on NET formation, NETs were induced in-vitro in porcine and human peripheral neutrophils following incubation with tacrolimus. RESULTS Repeated intra-graft administrations of TGMS-TAC minimized systemic toxicity and prolonged graft survival. Nevertheless, signs of rejection were observed at endpoint. Systemically, there were no increases in cytokine levels, complement anaphylatoxins, T-cell subpopulations, or neutrophils during rejection. Yet, tissue analysis showed local infiltration of T cells and neutrophils, together with neutrophil extracellular traps (NETs) in rejected grafts. Interestingly, intra-graft administration of tacrolimus contributed to a reduction in both T-cellular infiltration and NETs. In fact, in-vitro NETosis assessment showed a 62-84% reduction in NETs after stimulated neutrophils were treated with tacrolimus. CONCLUSION Our data indicate that the proposed local delivery of immunosuppression avoids off-target toxicity while prolonging graft survival in a multiple MHC-mismatch VCA model. Furthermore, NETs are found to play a role in graft rejection and could therefore be a potential innovative therapeutic target

Predicting risk factors that lead to free flap failure and vascular compromise: A single unit experience with 565 free tissue transfers.

BACKGROUND Even though the benefit of free tissue transfer is uncontested in complex reconstructive cases, vascular compromise and/or flap failure remain a challenge for the surgeon and identification of possible risk factors can aid in the preoperative planning. The aim of this study was to identify the individual risk factors leading to flap failure and/or vascular compromise in free tissue transfers in a single institution over a period of 10 years and to create an index predicting these problems, as well as finding predictors of other postoperative complications. METHODS Data from all the patients undergoing free tissue transfers between 2009 and 2018 were retrospectively analyzed (demographics, comorbidities, flap failure, vascular compromise, and other complications). The results from the univariate and multivariate analyses were used to create an index. RESULTS A predictability index with three classes (low, moderate, and high risk) was calculated for each patient, based on defect etiology and the presence of coronary heart disease, diabetes, smoking, peripheral arterial vascular disease, and arterial hypertension. A patient with moderate-risk index had 9.3 times higher chances of developing vascular compromise than those in the low-risk group, while a high-risk index had 18.6 higher odds (p=0.001). American Society of Anesthesiologists (ASA) classification was found to be a predictor of complications in free tissue transfer (p=0.001). CONCLUSION If patients at a high risk of vascular compromise could be identified preoperatively through this predictability index, patient counseling could be improved and the surgeon might adapt the reconstructive plan and choose an alternative reconstructive strategy