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.

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.

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.

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.

Recurrent neck myxofibrosarcoma: a case report.

BACKGROUND: Myxofibrosarcoma (MFS) is a rare soft tissue sarcoma with a high recurrence rate and a low risk of distant metastasis. It occurs mainly in the extremities of elderly men. Head and neck MFS is extremely rare. Surgery is the cornerstone of treatment. The role of radiotherapy (RT) and chemotherapy (CHT) on MFS is still debated. CASE PRESENTATION: A 67-year-old Caucasian man presented to our sarcoma referral center (SRC) with a history of MFS of the neck excised with microscopic positive surgical margins in a non-referral center. Staging imaging exams did not reveal distant metastasis. After a multidisciplinary discussion, preoperative RT was administered with a total dose of 50 Gy followed by wide surgical excision. Histological examination was negative for viable tumor cells. No relapse occurred during the 24-month postoperative follow-up. CONCLUSIONS: The case described suggests the importance of planned combined treatments with both RT and surgery for high-grade soft tissue sarcoma. RT seems to be promising within this specific histotype. Close follow-up is advisable in all cases. Further studies are needed to confirm if the observed efficacy of combined treatments results in a prolonged time of disease-free survival and overall survival.

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.

What About Gastric Schwannoma? A Review Article.

PURPOSE: Gastric schwannomas (GSs) are rare mesenchymal neoplasms of the gastrointestinal tract. Diagnosis is often achieved postoperatively, based on pathology reports of retrieved specimens. The aim of the present study is to follow up all patients with gastric schwannoma (Gs) undergoing endoscopic, partial, or more extended surgery and to evaluate the appearance of local or distant recurrence. METHODS: A PubMed, Cochrane, and Embase systematic review of the literature has been performed. Original papers, review articles, and case reports published between 1988 and 2019 were considered eligible. All the studies who met the inclusion criteria were analyzed. Statistical analysis of data has been performed using GraphPad Prism 7 software. RESULTS: Three hundred twenty-eight articles were found, and a total of 102 were included and analyzed in depth. Fifty-three papers reported the follow-up information, ranging from 1 to 417 months across different studies. Among them, 31 patients underwent endoscopic removal of the gastric lesions; 140 patients underwent local surgery, including wedge resection or partial gastrectomy; and 148 patients underwent subtotal or total gastrectomy. The median follow-up was of 27-38-33 months, respectively. No recurrence or distant metastasis was detected in the endoscopy group. Among local surgery group, liver metastasis was reported in one case; in extended surgery group, one patient died for multiple liver metastases. CONCLUSIONS: Local or more extended surgery involved a larger cohort of patients and reported satisfactory long-term results compared with endoscopy group. Surgery in absence of a definite preoperative diagnosis is considered the gold standard treatment for resectable Gs.

Locally recurrent extraskeletal myxoid chondrosarcoma of the shoulder: a case of complete neoadjuvant radiotherapy response.

BACKGROUND: Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue tumor that typically affects the lower limbs of men between the ages of 50 and 60. EMC of the shoulder is rare with a high risk of local recurrence and distant metastasis. A planned surgical excision in sarcoma referral centers (SRCs) is mandatory to obtain the best outcome. The role of chemotherapy (CHT) and Radiotherapy (RT) on soft tissue chondrosarcoma is still controversial. CASE PRESENTATION: A 47-year-old man presented to our referral center with a history of EMC in the right shoulder excised with microscopic positive surgical margins in a non-referral center. Staging imaging exams did not reveal distant metastasis or residual disease, but during follow-up a local recurrence was detected. After a multidisciplinary discussion, preoperative radiotherapy was administered with a total dose of 50 Gy, and then the patient underwent wide surgical excision. Histological examination was negative for viable tumor cells. No relapse occurred in a 24-months post-operative follow up. CONCLUSIONS: The case here described suggests the importance of patient's management in SRCs. A planned combined treatments with both surgery and RT seems to be the best choice to improve local control. RT seems to be promising within this specific histotype. Further studies are needed to confirm if the observed efficacy of combined treatments reflects in a consistent survival benefit for EMC patients.

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.

Highly efficient plasmon-mediated electron injection into cerium oxide from embedded silver nanoparticles.

The coupling with plasmonic metal nanoparticles (NPs) represents a promising opportunity to sensitize wide band gap oxides to visible light. The processes which come into play after the excitation of localized surface plasmon resonances (LSPRs) in the NPs largely determine the efficiency of the charge/energy transfer from the metal NP to the oxide. We report a study of plasmon-mediated energy transfer from mass-selected silver NPs into the cerium oxide matrix in which they are embedded. Femtosecond transient absorption spectroscopy is used to probe the dynamics of charge carrier relaxation after the excitation of the LSPR of the silver nanoparticles and to evaluate the plasmon-mediated electron transfer efficiency from the silver nanoparticles to the cerium oxide. High injection efficiencies in the 6-16% range have been identified for excitation between 400 and 600 nm. These high values have been explained in terms of plasmon-mediated direct electron injection as well as indirect hot electron injection from the NPs to the oxide. The information obtained provides an important contribution towards a knowledge-driven design of efficient cerium oxide based nanostructured materials for solar to chemical energy conversion.

Dynamics of the Interaction Between Ceria and Platinum During Redox Processes.

The work is focused on understanding the dynamics of the processes which occur at the interface between ceria and platinum during redox processes, by investigating an inverse catalytic model system made of ceria epitaxial islands and ultrathin films supported on Pt(111). The evolution of the morphology, structure and electronic properties is analyzed in real-time during reduction and oxidation, using low-energy electron microscopy and spatially resolved low-energy electron diffraction. The reduction is induced using different methods, namely thermal treatments in ultra-high vacuum and in H2 as well as deposition of Ce on the oxide surface, while re-oxidation is obtained by exposure to oxygen at elevated temperature. The use of two different epitaxial systems, continuous films and nanostructures, allows determining the influence of platinum proximity on the stabilization of the specific phases observed. The factors that limit the reversibility of the observed modifications with the different oxidation treatments are also discussed. The obtained results highlight important aspects of the cerium oxide/Pt interaction that are relevant for a complete understanding of the behavior of Pt/CeO2 catalysts.

Friction and Adhesion of Different Structural Defects of Graphene.

Graphene structural defects, namely edges, step-edges, and wrinkles, are susceptible to severe mechanical deformation and stresses under tribo-mechanical operations. Applied forces may cause deformation by folding, buckling, bending, and tearing of these defective sites of graphene, which lead to a remarkable decline in normal and friction load bearing capacity. In this work, we experimentally quantified the maximum sustainable normal and friction forces, corresponding to the damage thresholds of the different investigated defects as well as their pull-out (adhesion) forces. Horizontal wrinkles (with respect to the basal plane, i.e., folded) sustained the highest normal load, up to 317 nN, during sliding, whereas for vertical (i.e., standing) wrinkles, step-edges, and edges, the load bearing capacities are up to 113, 74, and 63 nN, respectively. The related deformation mechanisms were also experimentally investigated by varying the normal load up to the initiation of the damage from the defects and extended with the numerical results from molecular dynamics and finite element method simulations.

Imatinib rechallenge in patients with advanced gastrointestinal stromal tumors following progression with imatinib, sunitinib and regorafenib.

BACKGROUND: Rechallenge with imatinib is an option in advanced gastrointestinal stromal tumor (GIST) patients following progression with standard tyrosine-kinase inhibitors (TKIs), imatinib, sunitinib and regorafenib. We retrospectively collected data from metastatic Italian GIST patients treated with imatinib resumption after progression to conventional TKIs. METHODS: A total of 104 eligible advanced GIST patients, previously treated with imatinib, sunitinib and regorafenib, were collected from six referral Italian institutions. Mutational analysis was recorded and correlated with survival and response according to RECIST 1.1 or CHOI criteria. RESULTS: Overall, 71 patients treated with imatinib 400 mg as rechallenge were included. Mutational status was available in all patients. The median follow up was 13 months. In patients who received a rechallenge therapy, the median time to progression (TTP) was 5.4 months [95% confidence interval (CI) 1.9-13.5] and overall survival (OS) was 10.6 months (95% CI 2.8-26.9). A correlation between mutational status, response rate, TTP and OS was not found but comparing deleted versus nondeleted KIT exon 11 patients, a significant difference was identified in terms of TTP and OS (p = 0.04 and p = 0.02, respectively). CONCLUSIONS: Our retrospective data confirm that imatinib rechallenge is a reasonable option in advanced GIST. The prognostic value of the specific KIT mutations was confirmed in our series.

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.