Thigh reconstruction between form and function: An algorithm for flap selection based on a series of 70 oncological patients.

INTRODUCTION: Thigh reconstruction after oncological resection represents a challenge in terms of ideal morphological and functional outcomes to aim for. Very few papers presented a comprehensive approach to this topic, most of them being only small cases series. The purpose of this article was to review our institutional experience in the field of thigh soft-tissue reconstruction, proposing an algorithm to choose the most convenient pedicled or free flap approach according to the different clinical scenarios and the specific morpho-functional requirements of the case. PATIENTS AND METHODS: The authors retrospectively reviewed patients who received flap reconstruction for thigh soft-tissue defects after oncological resection between 2014 and 2021. Demographic and operative data were recorded. Twelve months post-operatively, patients were asked to rate the esthetic and functional outcomes of the reconstructive procedure on a 5-point Likert scale. Additionally, for patients receiving a free functional muscle transfer to restore quadriceps or hamstring function, recovery was evaluated with the Medical Research Council Scale for Muscle Strength. RESULTS: Seventy flap reconstructions of the thigh were, respectively, performed after sarcoma (n = 43), melanoma (n = 13) and non-melanoma skin cancer (n = 14) resection. Pedicled flaps were used in 55 patients: 46 perforator flaps (32 ALT, 4 AMT, 4 PAP, 2 TFL, 2 MSAP, 2 DIEP) and 9 muscle or myocutaneous flaps (4 medial gastrocnemius, 2 gracilis, and 3 VRAM). Microsurgical reconstruction was performed in 15 patients for extensive defects (2 SCIP, 1 latissimus dorsi-LD, 1 thoracodorsal artery perforator-TDAP, 1 ALT, 2 DIEP flaps) or when >50% of the quadriceps or hamstring compartments were resected (eight free functional muscle transfer including five vastus lateralis, two LD, and one rectus femoris). Extensive defect surface, previous irradiation and neoadjuvant chemotherapy appeared to be predictors of free flap reconstruction. Complication (49% vs. 26.6%; p > .05) and readmission rates (32.7% vs. 13.3%; p > .05) were comparable between pedicled and free flap groups, as well as complications severity scores according to Clavien-Dindo classification (1.15 vs. 1.29; p > .05). However, patients with previous irradiation experienced worse outcomes when receiving pedicled rather than free flaps in terms of reintervention (87.5% vs. 28.6%; p = .04) and readmission rates (87.5% vs. 14.29%; p = .01), and severity of surgical complications. Overall patients' satisfaction was high, with esthetic and functional mean score of 4.31 and 4.12, respectively (p > .05). In the FFMT group, M5, M4, M3, and M2 strength was observed in 3, 3, 1, and 1 patients, respectively. CONCLUSION: Oncological thigh defects are usually well addressed with pedicled perforator flaps. Microsurgical reconstruction offers reliable and reproducible results in extensive defects and in previously irradiated fields or when functional restoration is indicated.

Organ Infiltration and Patient Risk After Multivisceral Surgery for Primary Retroperitoneal Liposarcomas.

BACKGROUND: The extent of histological organ involvement (HOI) to organs and structures of a retroperitoneal liposarcoma may have prognostic implications. This study investigated incidence, characteristics, and risk association of HOI in these patients. PATIENTS AND METHODS: Data of patients who underwent multivisceral resection for primary liposarcoma (2009-2014) were retrospectively analyzed. HOI was the variable of interest and was classified into four degrees: absent (HOI-0), perivisceral (HOI-1), initial (HOI-2), and advanced (HOI-3). Primary endpoint was overall survival (OS). Secondary endpoint was disease-free survival (DFS). The prognostic value of HOI was adjusted for preoperative treatment and the Sarculator nomogram score. RESULTS: A total of 109 patients were included. HOI-0, HOI-1, HOI-2, and HOI-3 were detected in 9 (8.3%), 11 (10.1%), 43 (39.4%), and 46 (42.2%) patients. Median follow-up was 8.4 years [interquartile range (IQR) 7.2-9.6 years]. There were 68 recurrences and 50 patient deaths observed, resulting in a 10-year OS and DFS of 51.1% [95% confidence interval (CI) 41.9-62.1%] and 34.1% (95% CI 25.2-46.1%), respectively. Clinically relevant HOIs (HOI-2 and HOI-3) were found in 35/45 (77.8%) and 54/64 (84.4%) cases of well- and de-differentiated liposarcomas, respectively. On multivariable survival analysis, patients with HOI-3 had significantly shorter OS (HOI-3 vs HOI-0/HOI-1 HR 2.92; p = 0.012) and DFS (HOI-3 vs HOI-0/HOI-1 HR 2.23; p = 0.045), independently of the nomogram score (OS: HR 2.93; p < 0.001; DFS: HR 1.78; p = 0.003). CONCLUSIONS: Initial and advanced HOIs are frequently detected in both well-differentiated and de-differentiated liposarcomas, supporting that multivisceral resection may be needed. HOI stratifies the risk of patients with primary retroperitoneal liposarcoma.

Abdominal wall reconstruction with the free functional L-shaped latissimus dorsi flap: A case report.

Extensive tridimensional defects of the abdominal wall are usually addressed with soft tissue flaps combined with meshes. In this scenario, the additional value of dynamic abdominal wall reconstruction with functional flaps has yet to be demonstrated. In this paper the authors describe for the first time a unique case of total abdominal wall reconstruction with the free functional L-shaped latissimus dorsi (LD) flap, designed to increase the surface area of skin flap coverage while minimizing donor site morbidity, highlighting technical tips and long-term outcomes. A 65-year-old patient underwent abdominal wall resection for a dermatofibrosarcoma protuberans, leaving her with a 23 × 15 cm full-thickness defect. After placing a mesh, a myo-cutaneous free LD Flap with an L-shaped configuration was planned. The flap was composed of Paddle A, designed vertically along the anterior margin of the muscle and Paddle B, designed over the inferior aspect of the LD muscle, extending obliquely from the midline and intersecting Paddle A laterally with a 60° angle. End-to-end anastomoses to the deep inferior epigastric artery and vein and thoracodorsal nerve coaptation to a sizeable intercostal nerve were performed. The LD muscle was sutured according to its native tension while the two skin islands allowed an almost complete resurfacing of the abdominal wall defect. Donor site was closed primarily. Post-operative course was uneventful. One year postoperatively, good abdominal contour was observed, with adequate abdominal tone at rest in laying and standing position. Muscle neurotization was confirmed with clinical examination showing voluntary contraction of the transplanted muscle and the patient reported very high functional outcomes at the hernia-related quality-of-life (HerQles) questionnaire. The free L-shaped LD flap represents an innovative solution to reconstruct extensive full-thickness defects of the abdominal wall while reducing donor site morbidity. Flap neurotization should be attempted whenever possible to improve functional outcomes of the procedure.

How I Treat Localized Soft Tissue Sarcomas: Update on Diagnosis, Risk Stratification, and Treatment.

BACKGROUND: Adult-type soft tissue sarcomas (STSs) are rare tumors representing about 1% of all adult malignant tumors. Their extreme histological heterogeneity places them among the most challenging fields of diagnostic pathology. The variability of clinical and prognostic presentation between the various histotypes reflects the different management that should be followed on a case-by-case basis. These features make STSs the case in point of how important it is a centralized and multidisciplinary approach. SUMMARY: Surgery represents the mainstay in the treatment of localized STSs. Recently, more and more studies are making efforts to understand what the contribution of chemotherapy and radiotherapy with neoadjuvant and adjuvant intent may be both in unselected and selected histological subgroups. In fact, despite the improvement in overall survival seen in the past few years thanks to the adoption of a more radical surgical approach, mortality remains relatively high and the 5-year overall survival is around 65%. KEY MESSAGES: In this review, we comment upon the treatment of localized STSs of the extremity, trunk wall, and retroperitoneum and how surgery, radiotherapy, and chemotherapy can be integrated with each other and individually tailored. Nomograms can assist clinicians in this complex therapeutic decision-making process, through the identification of patients at higher risk of death or disease relapse.

Graphene Confers Ultralow Friction on Nanogear Cogs.

Friction-induced energy dissipation impedes the performance of nanomechanical devices. Nevertheless, the application of graphene is known to modulate frictional dissipation by inducing local strain. This work reports on the nanomechanics of graphene conformed on different textured silicon surfaces that mimic the cogs of a nanoscale gear. The variation in the pitch lengths regulates the strain induced in capped graphene revealed by scanning probe techniques, Raman spectroscopy, and molecular dynamics simulation. The atomistic visualization elucidates asymmetric straining of CC bonds over the corrugated architecture resulting in distinct friction dissipation with respect to the groove axis. Experimental results are reported for strain-dependent solid lubrication which can be regulated by the corrugation and leads to ultralow frictional forces. The results are applicable for graphene covered corrugated structures with movable components such as nanoelectromechanical systems, nanoscale gears, and robotics.

Morbidity and Outcomes After Distal Pancreatectomy for Primary Retroperitoneal Sarcoma: An Analysis by the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group.

BACKGROUND: Multi-visceral resection often is used in the treatment of retroperitoneal sarcoma (RPS). The morbidity after distal pancreatectomy for primary pancreatic cancer is well-documented, but the outcomes after distal pancreatectomy for primary RPS are not. This study aimed to evaluate morbidity and oncologic outcomes after distal pancreatectomy for primary RPS. METHODS: In this study, 26 sarcoma centers that are members of the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) retrospectively identified consecutive patients who underwent distal pancreatectomy for primary RPS from 2008 to 2017. The outcomes measured were 90-day severe complications (Clavien-Dindo ≥ 3), postoperative pancreatic fistula (POPF) rate, and oncologic outcomes. RESULTS: Between 2008 and 2017, 280 patients underwent distal pancreatectomy for primary RPS. The median tumor size was 25 cm, and the median number of organs resected, including the pancreas, was three. In 96% of the operations, R0/R1 resection was achieved. The 90-day severe complication rate was 40 %. The grades B and C POPF complication rates were respectively 19% and 5% and not associated with worse overall survival. Administration of preoperative radiation and factors to mitigate POPF did not have an impact on the risk for the development of a POPF. The RPS invaded the pancreas in 38% of the patients, and local recurrence was doubled for the patients who had a microscopic, positive pancreas margin (hazard ratio, 2.0; p = 0.042). CONCLUSION: Distal pancreatectomy for primary RPS has acceptable morbidity and oncologic outcomes and is a reasonable approach to facilitate complete tumor resection.

Optical and electronic properties of silver nanoparticles embedded in cerium oxide.

Wide bandgap oxides can be sensitized to visible light by coupling them with plasmonic nanoparticles (NPs). We investigate the optical and electronic properties of composite materials made of Ag NPs embedded within cerium oxide layers of different thickness. The electronic properties of the materials are investigated by x-ray and ultraviolet photoemission spectroscopy, which demonstrates the occurrence of static charge transfers between the metal and the oxide and its dependence on the NP size. Ultraviolet-visible spectrophotometry measurements show that the materials have a strong absorption in the visible range induced by the excitation of localized surface plasmon resonances. The plasmonic absorption band can be modified in shape and intensity by changing the NP aspect ratio and density and the thickness of the cerium oxide film.

Use of Cardioprotective Dexrazoxane Is Associated with Increased Myelotoxicity in Anthracycline-Treated Soft-Tissue Sarcoma Patients.

BACKGROUND: Dexrazoxane (DEX) is indicated as a cardioprotective agent for breast cancer patients receiving the anthracycline doxorubicin. Two meta-analyses in metastatic breast cancer reported an apparent increase in the severity of myelosuppression when DEX was used. So far, no data in soft-tissue sarcoma (STS) patients are available. METHODS: We retrospectively analyzed hematological toxicity data from 133 consecutive STS patients who received a chemotherapy regimen containing an anthracycline and ifosfamide (AI) in the perioperative or metastatic settings between January 2006 and December 2017. Of these, 46 received off-label DEX concurrently with the AI treatment. The differences between incidence of any of the explored outcomes were assessed according to the Fisher exact test. RESULTS: Compared with the non-DEX group, DEX treatment was associated with significantly higher rates of grade 3/4 hematological toxicities: leukopenia (56.5 vs. 28.7%; p = 0.0014), neutropenia (69.6 vs. 24.1%; p = 0.0001), febrile neutropenia (52.2 vs. 20.7%; p = 0.0004), anemia (41.3 vs. 28.7%; p = 0.1758), and thrombocytopenia (54.3 vs. 32.1%; p = 0.0159). Similarly, in the DEX group dose reductions were more frequent compared to the non-DEX group (39.1 vs. 19.5%; p = 0.0221). CONCLUSION: Adding DEX to AI in STS patients leads to higher rates of bone marrow suppression in all blood components, as well as to more frequent events of febrile neutropenia and dose reductions.

Body Mass Index as a Risk Factor for Toxicities in Patients with Advanced Soft-Tissue Sarcoma Treated with Trabectedin.

OBJECTIVES: Low body mass index (BMI) and/or low lean body mass have been shown to be risk factors for chemotherapy-related toxicities in a number of different cancers. However, no data are available regarding the role of BMI as a risk factor for developing toxicities related to the novel anticancer agent, trabectedin, in patients with soft-tissue sarcoma (STS). We evaluated the role of BMI as a risk factor for trabectedin-related toxicity in patients with STS. METHODS: Data from 51 patients with metastatic/advanced STS treated with trabectedin after progression on ≥1 anthracycline ± ifosfamide regimen were retrospectively reviewed. RESULTS: Eighteen patients (35.3%) were underweight, and the remainder were of normal bodyweight (45.1%) or overweight (19.6%). Neutropenia of any grade (77.8 vs. 33.3%) and grade 3-4 neutropenia (50.0 vs. 18.2%) occurred more frequently in the underweight versus normal/overweight patients (p = 0.025). Febrile neutropenia also occurred more frequently in underweight patients. Differences remained statistically significant after adjusting for other predictors of toxicity. There were no significant differences in other hematological and nonhematological toxicities between the groups. CONCLUSIONS: The data suggest for the first time that BMI should be considered a risk factor for neutropenia in patients with STS treated with trabectedin.

Role of cerium oxide in bioactive glasses during catalytic dissociation of hydrogen peroxide.

The addition of cerium oxide to bioactive glasses, important materials for bone tissue regeneration, has been shown to induce multifunctionality, combining a significant bioactivity with antioxidant properties. We provide a real time investigation of the evolution of the electronic properties of highly diluted cerium ions in a liquid environment containing hydrogen peroxide - the most abundant reactive oxygen species in living cells. This challenging task is undertaken by means of high-energy resolution fluorescence detected by X-ray absorption near-edge spectroscopy at the Ce L3 edge. We investigate samples with variable compositions and different morphologies. We relate the observed spectroscopic changes not only to variations in the concentration of the two Ce oxidation states in the samples, but also to changes in the local atomic environment of Ce ions, providing a clear picture of the role of cerium ions in the dissociation of hydrogen peroxide. The obtained results contribute to the understanding of the mechanisms that come into play in the process and provide a basis for the optimization of the functionalities of this class of materials.

Contraction, cation oxidation state and size effects in cerium oxide nanoparticles.

An accurate description of the structural and chemical modifications of cerium oxide nanoparticles (NPs) is mandatory for understanding their functionality in applications. In this work we investigate the relation between local atomic structure, oxidation state, defectivity and size in cerium oxide NPs with variable diameter below 10 nm, using x-ray absorption fine structure analysis in the near and extended energy range. The NPs are prepared by physical methods under controlled conditions and analyzed in morphology and crystalline quality by high resolution transmission electron microscopy. We resolve here an important question on the local structure of cerium oxide NPs: we demonstrate a progressive contraction in the Ce-O interatomic distance with decreasing NP diameter and we relate the observed effect to the reduced dimensionality. The contraction is not significantly modified by inducing a 4%-6% higher Ce3+ concentration through thermal annealing in high vacuum. The consequences of the observed average cation-anion distance contraction on the properties of the NPs are discussed.

Influence of defect distribution on the reducibility of CeO2-x nanoparticles.

Ceria nanoparticles (NPs) are fundamental in heterogeneous catalysis because of their ability to store or release oxygen depending on the ambient conditions. Their oxygen storage capacity is strictly related to the exposed planes, crystallinity, density and distribution of defects. In this work a study of ceria NPs produced with a ligand-free, physical synthesis method is presented. The NP films were grown by a magnetron sputtering based gas aggregation source and studied by high resolution- and scanning-transmission electron microscopy and x-ray photoelectron spectroscopy. In particular, the influence of the oxidation procedure on the NP reducibility has been investigated. The different reducibility has been correlated to the exposed planes, crystallinity and density and distribution of structural defects. The results obtained in this work represent a basis to obtain cerium oxide NP with desired oxygen transport properties.

Electronic properties of epitaxial cerium oxide films during controlled reduction and oxidation studied by resonant inelastic X-ray scattering.

We investigated the evolution of the electronic structure of cerium oxide ultrathin epitaxial films during reduction and oxidation processes using resonant inelastic X-ray scattering at the Ce L3 absorption edge, a technique sensitive to the electronic configurations at the 4f levels and in the 5d band thanks to its high energy resolution. We used thermal treatments in high vacuum and in oxygen partial pressure to induce a controlled and reversible degree of reduction in cerium oxide ultrathin epitaxial films of different thicknesses. Two dominant spectral components contribute to the measured spectra at the different degrees of oxidation/reduction. In ultrathin films a modification of the electronic properties associated with platinum substrate proximity and with dimensionality is identified. The different electronic properties induce a higher reducibility in ultrathin films, ascribed to a decrease of the surface oxygen vacancy formation energy.

Tunability of exchange bias in Ni@NiO core-shell nanoparticles obtained by sequential layer deposition.

Films of magnetic Ni@NiO core-shell nanoparticles (NPs, core diameter d ≅ 12 nm, nominal shell thickness variable between 0 and 6.5 nm) obtained with sequential layer deposition were investigated, to gain insight into the relationships between shell thickness/morphology, core-shell interface, and magnetic properties. Different values of NiO shell thickness t(s) could be obtained while keeping the Ni core size fixed, at variance with conventional oxidation procedures where the oxide shell is grown at the expense of the core. Chemical composition, morphology of the as-produced samples and structural features of the Ni/NiO interface were investigated with x-ray photoelectron spectroscopy and microscopy (scanning electron microscopy, transmission electron microscopy) techniques, and related with results from magnetic measurements obtained with a superconducting quantum interference device. The effect of the shell thickness on the magnetic properties could be studied. The exchange bias (EB) field H(bias) is small and almost constant for ts up to 1.6 nm; then it rapidly grows, with no sign of saturation. This behavior is clearly related to the morphology of the top NiO layer, and is mostly due to the thickness dependence of the NiO anisotropy constant. The ability to tune the EB effect by varying the thickness of the last NiO layer represents a step towards the rational design and synthesis of core-shell NPs with desired magnetic properties.

Incidence and prognostic impact of para-aortic lymph nodes metastases during pancreaticoduodenectomy for peri-ampullary cancer.

BACKGROUND: Standard lymphadenectomy during pancreaticoduodenectomy (PD) for peri-ampullary cancer does not include the routine removal of para-aortic lymph nodes (PALN) (station 16, according to the JPS staging system). The aim of this study was to report the incidence and the prognostic value of PALN metastases in patients undergoing PD for peri-ampullary cancer. MATERIALS AND METHODS: One hundred thirty-five consecutive patients who underwent PD and PALN dissection for peri-ampullary cancer were prospectively evaluated. The relationship between clinicopathological factors, including PALN metastases and survival was evaluated at univariate and multivariate analysis. RESULTS: PALN metastases (N16+) were found in 11.1% of cases. At univariate analysis, R1 resection, metastatic nodes different from para aortic (N1) and N16+ significantly affected patients' prognosis. Compared with N16+, the median overall survival (OS) of N0 patients was significantly longer (32 versus 69 months, respectively; P < 0.05), whereas no difference was found between N16+ and N1 patients (32 versus 34 months, respectively) (P > 0.05). At multivariate analysis, only R1 resection reached statistical significance and was confirmed an independent prognostic factor. CONCLUSIONS: Neoplastic involvement of PALN in peri-ampullary cancer is frequent and, so, their removal during PD could be justified. Moreover, PALN metastases should be not considered an absolute contraindication to radical surgery.

Origin of hydrophobicity in FIB-nanostructured Si surfaces.

Surface morphology has been demonstrated to influence the tribological properties at different scales, but the phenomena which occur at the nanoscale have not been completely understood. The present study reports on the effect of focused ion beam nanopatterning on coefficient of friction (CoF) and adhesion of Si(001) surface covered by native oxide. Regular arrays of nanogrooves reduce both CoF and adhesion, related to a hydrophobic character of the patterned surface, but this effect disappears as soon as the separation among the nanostructures approaches the microscopic scale. The dependence of this hydrophobic effect on the pitch is not linked to the corresponding contact area. It has been found that each nanostructure is surrounded by a low-friction region which extends some hundreds of nanometers from it. For pitches of 125 and 250 nm these low-friction regions completely overlap, generating a consistent decrease in CoF and adhesion, while for pitches of 500 and 1000 nm their effect is negligible. The low-friction regions were not observed in humidity-free ambient, indicating that they are the origin of patterns of hydrophobicity.