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).

No abstract

No abstract

BackgroundDistal 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 methodsA 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.ResultsAll 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.ConclusionsBioglass-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.

Metal oxide nanoparticles have emerged as exceptionally potent biomedical sensors and actuators due to their unique physicochemical features. Despite fascinating achievements, the current limited understanding of the molecular interplay between nanoparticles and the surrounding tissue remains a major obstacle in the rationalized development of nanomedicines, which is reflected in their poor clinical approval rate. This work reports on the nanoscopic characterization of inorganic nanoparticles in tissue by the example of complex metal oxide nanoparticle hybrids consisting of crystalline cerium oxide and the biodegradable ceramic bioglass. A validated analytical method based on semiquantitative X‐ray fluorescence and inductively coupled plasma spectrometry is used to assess nanoparticle biodistribution following intravenous and topical application. Then, a correlative multiscale analytical cascade based on a combination of microscopy and spectroscopy techniques shows that the topically applied hybrid nanoparticles remain at the initial site and are preferentially taken up into macrophages, form apatite on their surface, and lead to increased accumulation of lipids in their surroundings. Taken together, this work displays how modern analytical techniques can be harnessed to gain unprecedented insights into the biodistribution and biotransformation of complex inorganic nanoparticles. Such nanoscopic characterization is imperative for the rationalized engineering of safe and efficacious nanoparticle‐based systems.

Seroma formation is a well-recognized postoperative complication for many plastic and general surgical procedures. Although various tissue adhesives and substances have been used in an effort to treat seroma formation, no therapies have been established clinically. Recently, the nano-bridging phenomenon has been introduced as a promising approach to achieve tissue adhesion and strong closure of deep skin wounds in rats. The present study seeks to assess the potential of nano-bridging beyond skin wounds in a rat model of seroma. Seromas were induced in 20 Lewis rats through bilateral axillary lymphadenectomy, excision of the latissimus dorsi and cutaneous maximus muscles, and disruption of dermal lymphatics. On postoperative day (POD) 7, the seroma was aspirated on both sides. A bioactive nanoparticle (NP) suspension based on zinc-doped strontium-substituted bioglass/ceria nanoparticles (NP group) or fibrin glue (fibrin group) was injected into the right seroma cavity, while the left side was left untreated. On POD 14, the NP group showed complete remission (no seromas at all), while the fibrin group recorded a reduction of only 63% in the seroma fluid volume. The NPs exerted local antiinflammatory and neo-angiogenic effects, without any detectable systemic changes. Moreover, the ceria levels recorded in the organs did not surpass the background level, indicating that the nanoparticles stayed at the site of application. This study is a promising first example demonstrating the ability of inorganic nanoparticle formulations to reduce seroma formation in a rat model, without any detectable systemic adverse effects. These results emphasize the potential of nanotechnological solutions in the therapeutic management of seroma in the clinical setting.

Background: Defects in the distal third of the leg are difficult to cover and often require free tissue transfer, even for defects of limited sizes. Propeller flaps have been designed specifically as an alternative to free tissue transfer but at times have been associated with unacceptably high complication rates. We therefore aimed to prospectively assess our own institutional experience with this technique and to define its role in lower-limb reconstruction. Methods: All patients who had been managed with reconstruction of the distal part of the leg with a propeller flap between 2014 and 2017 were included in the study. Demographic, clinical, and follow-up data on the patients and surgical procedures were recorded with special focus on the complication profile. Results: Twenty-six patients underwent propeller flap reconstruction of the distal part of the leg: 12 flaps were based on the posterior tibial artery, and 14 were based on the peroneal artery. Postoperative complications developed in association with 1 of the 12 flaps based on the posterior tibial artery, compared with 8 of the 14 flaps based on the peroneal artery (p = 0.015). Moreover, the presence of a higher Charlson comorbidity index (≥2) was strongly associated with the development of postoperative complications (p < 0.001). Conclusions: Propeller flaps are a reliable option for traumatic reconstruction in carefully selected patients with lower-limb defects. In our experience, the rate of complications was higher for propeller flaps based on the peroneal artery and for patients with a Charlson comorbidity index of ≥2, whereas posterior tibial artery-based propeller flap reconstruction was a reliable surgical option for patients with a small defect in the distal third of the lower limb. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Introduction:The incidence of malignant melanoma has been rising steadily over the past decades and Merkel cell carcinoma is a highly aggressive neuroendocrine skin tumor with a high mortality rate. Sentinel lymph node (SLN) biopsy is a recommended prognostic tool in primary cutaneous malignant melanomas of intermediate thickness and in all clinically node-negative Merkel cell carcinomas. The gold standard method for identification of SLNs is lymphoscintigraphy, which involves radioactive tracers. Indocyanine green-based near-infrared fluorescence imaging (NIRFI) has been also used for intraoperative SLN identification. We aim to evaluate the diagnostic sensitivity of the VisionSense VS3 NIRFI device for SNL identification. This device uses stereoscopic 3D high definition for both fluorescence and visible light imaging. Our hypothesis is that SLNs may be identified transcutaneously using fluorescent dye injections and NIRFI; therefore, obviating the need for lymphoscintigraphy in the future.Methods and analysis: lymph node identification in skin malignancy using indocyanine green transcutaneously is a prospective diagnostic sensitivity study conducted at the