Several imaging methodologies have been used in biofilm studies, contributing to deepening the knowledge on their structure. This review illustrates the most widely used microscopy techniques in biofilm investigations, focusing on traditional and innovative scanning electron microscopy techniques such as scanning electron microscopy (SEM), variable pressure SEM (VP-SEM), environmental SEM (ESEM), and the more recent ambiental SEM (ASEM), ending with the cutting edge Cryo-SEM and focused ion beam SEM (FIB SEM), highlighting the pros and cons of several methods with particular emphasis on conventional SEM and VP-SEM. As each technique has its own advantages and disadvantages, the choice of the most appropriate method must be done carefully, based on the specific aim of the study. The evaluation of the drug effects on biofilm requires imaging methods that show the most detailed ultrastructural features of the biofilm. In this kind of research, the use of scanning electron microscopy with customized protocols such as osmium tetroxide (OsO₄), ruthenium red (RR), tannic acid (TA) staining, and ionic liquid (IL) treatment is unrivalled for its image quality, magnification, resolution, minimal sample loss, and actual sample structure preservation. The combined use of innovative SEM protocols and 3-D image analysis software will allow for quantitative data from SEM images to be extracted; in this way, data from images of samples that have undergone different antibiofilm treatments can be compared.

Introduction: Acute limb ischemia (ALI), classified according to Rutherford’s classification (RC), is a vascular emergency burdened by high rates of mortality and morbidity. The need of new and different prognostic values for ALI has emerged, and, among all, the neutrophil-to-lymphocyte ratio (NLR) has been proven as a strong outcome predictor in vascular disease. The aim of this study is to investigate the role of preoperative NLR in predicting clinical outcomes in patients presenting acute limb ischemia. Material and Methods: A single-center retrospective study was conducted between January 2015 and December 2019. Demographic and clinical characteristics, procedural technical aspects, postoperative and early (up to 30-day) outcomes were recorded. All enrolled patients were categorized into low- and high-NLR at baseline, using a cut-off value of 5. Study outcomes were 30-day all-cause mortality and amputation rates. Results: A total of 177 ALI patients were included in the final analysis (6 RC I, 44 RC IIA, 108 RC IIB, and 19 RC III), 115 males (65%), mean age 78.9 ± 10.4 years. Mean NLR at hospital presentation was 6.65 ± 6.75 (range 0.5–35.4), 108 (61.1%) patients presented a low-NLR, 69 (38.9%) a high-NLR. Immediate technical success was achieved in 90.1% of cases. At 30 days, freedom from amputation and freedom from death rates were 87.1% and 83.6%, respectively. At the univariate analysis, amputation (p < 0.0001, OR: 9.65, 95%CI: 3.7–25.19), mortality (p = 0.0001, OR: 9.88, 95%CI: 3.19–30.57), and cumulative event rates (p < 0.001, OR: 14.45, 95%CI: 6.1–34.21), were significantly different between the two groups according to NLR value. Multivariate analysis showed that a high baseline NLR value was an independent predictor of unfavorable outcomes in all enrolled patients. Consistently, at ROC analysis, a preoperative NLR > 5 was strongly associated with all outcome occurrences. Conclusion: Preoperative NLR value seems to be strongly related to ALI outcomes in this unselected population. The largest series should be evaluated to confirm present results.

Background: Identifying sex-related differences/variables associated with 30 day/1 year mortality in patients with chronic limb-threatening ischemia (CLTI). Methods: Multicenter/retrospective/observational study. A database was sent to all the Italian vascular surgeries to collect all the patients operated on for CLTI in 2019. Acute lower-limb ischemia and neuropathic-diabetic foot are not included. Follow-up: One year. Data on demographics/comorbidities, treatments/outcomes, and 30 day/1 year mortality were investigated. Results: Information on 2399 cases (69.8% men) from 36/143 (25.2%) centers. Median (IQR) age: 73 (66–80) and 79 (71–85) years for men/women, respectively (p < 0.0001). Women were more likely to be over 75 (63.2% vs. 40.1%, p = 0.0001). More men smokers (73.7% vs. 42.2%, p < 0.0001), are on hemodialysis (10.1% vs. 6.7%, p = 0.006), affected by diabetes (61.9% vs. 52.8%, p < 0.0001), dyslipidemia (69.3% vs. 61.3%, p < 0.0001), hypertension (91.8% vs. 88.5%, p = 0.011), coronaropathy (43.9% vs. 29.4%, p < 0.0001), bronchopneumopathy (37.1% vs. 25.6%, p < 0.0001), underwent more open/hybrid surgeries (37.9% vs. 28.8%, p < 0.0001), and minor amputations (22% vs. 13.7%, p < 0.0001). More women underwent endovascular revascularizations (61.6% vs. 55.2%, p = 0.004), major amputations (9.6% vs. 6.9%, p = 0.024), and obtained limb-salvage if with limited gangrene (50.8% vs. 44.9%, p = 0.017). Age > 75 (HR = 3.63, p = 0.003) is associated with 30 day mortality. Age > 75 (HR = 2.14, p < 0.0001), nephropathy (HR = 1.54, p < 0.0001), coronaropathy (HR = 1.26, p = 0.036), and infection/necrosis of the foot (dry, HR = 1.42, p = 0.040; wet, HR = 2.04, p < 0.0001) are associated with 1 year mortality. No sex-linked difference in mortality statistics. Conclusion: Women exhibit fewer comorbidities but are struck by CLTI when over 75, a factor associated with short- and mid-term mortality, explaining why mortality does not statistically differ between the sexes.

Vascular graft infection (VGI) is a rare but severe complication of vascular surgery that is associated with a bad prognosis and high mortality rate. An accurate and prompt identification of the infection and its extent is crucial for the correct management of the patient. However, standardized diagnostic algorithms and a univocal consensus on the best strategy to reach a diagnosis still do not exist. This review aims to summarize different radiological and Nuclear Medicine (NM) modalities commonly adopted for the imaging of VGI. Moreover, we attempt to provide evidence-based answers to several practical questions raised by clinicians and surgeons when they approach imaging in order to plan the most appropriate radiological or NM examination for their patients.

Detecting microcalcifications in atherosclerotic plaques by a simple trichromic staining method for epoxy embedded carotid endarterectomies

Purpose: We aimed at comparing ^99mTc-HMPAO white blood cells (^99mTc-WBC) scintigraphy, 18fluorine-fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) and CT angiography (CTA) in patients with suspected abdominal vascular graft or endograft infection (VGEI). Moreover, we attempted to define a new visual score for interpreting [¹⁸F]FDG PET/CT scans aiming at increasing its specificity. Methods: We prospectively compared ^99mTc-WBC SPECT/CT, [¹⁸F]FDG PET/CT, and CTA in 26 patients with suspected abdominal VGEI. WBC scans were performed and interpreted according to EANM recommendations. [¹⁸F]FDG PET/CT studies were assessed with both qualitative (Sah’s scale and new visual score) and semi-quantitative analyses. CTA images were interpreted according to MAGIC criteria. Microbiology, histopathology or a clinical follow-up of at least 24 months were used to achieve final diagnosis. Results: Eleven out of 26 patients were infected. [¹⁸F]FDG PET/CT showed 100% sensitivity and NPV, with both scoring systems, thus representing an efficient tool to rule out the infection. The use of a more detailed scoring system provided statistically higher specificity compared to the previous Sah’s scale (p = 0.049). ^99mTc-WBC SPECT/CT provided statistically higher specificity and PPV than [¹⁸F]FDG PET/CT, regardless the interpretation criteria used and it can be, therefore, used in early post-surgical phases or to confirm or rule out a PET/CT finding. Conclusions: After CTA, patients with suspected late VGEI should perform a [¹⁸F]FDG PET/CT given its high sensitivity and NPV. However, given its lower specificity, positive results should be confirmed with ^99mTc-WBC scintigraphy. The use of a more detailed scoring system reduces the number of ^99mTc-WBC scans needed after [¹⁸F]FDG PET/CT. Nevertheless, in suspected infections within 4 months from surgery, ^99mTc-WBC SPECT/CT should be performed as second exam, due to its high accuracy in differentiating sterile inflammation from infection.