Abstract Introduction: Vascular graft infections are a rare and severe complication of open aortic surgery. As such, strategies to improve diagnosis and management are paramount. Nevertheless, there is little evidence regarding the factors associated with a higher susceptibility of infection. Moreover, there is little consensus on the best diagnostic workup and most adequate approaches to control and mitigate this surgical complication. We aim to summarize the latest evidence on aortic graft infection through a narrative review. Methods: We conducted a literature search in a medical database (PubMed) and included studies on vascular graft infection and aortic repair. Results: So far, patient-related comorbidities (such as diabetes, smoking, advanced age and chronic kidney disease), as well as procedure-related factors (location and type of graft, postoperative hyperglycemia, bacteremia, emergency setting), have been reported. Unlike extracavitary infections, aortic graft infections may present with subtle or no clinical manifestations. Aortoenteric fistulas are the exception to the rule, carrying a significantly higher mortality rate. All patients should be thoroughly tested with full blood counts, blood cultures and extensive imaging studies. Adequate antibiotic therapy is one of the pillars of treatment and should not be delayed. The selection of the antimicrobial regimen should be personalized and made in a multidisciplinary team. Surgical strategies are of paramount importance in controlling infection. These can be divided into graft-sparing techniques and graft explantation. The choice of the appropriate approach depends on the surgeon’s experience, the extent of disease and the patient’s general status and comorbidities. Conclusion: Aortic graft infections are a rare and severe complication of vascular surgery. A swift diagnosis and management are paramount. Despite significant efforts on how to treat the infection with more adequate antibiotic and surgical therapies, effective preventive measures and a clear definition of predisposing factors remain the main areas for future studies.

Abstract Introduction: To assess the association of neutrophil-to-lymphocyte ratio (NLR) with post-stroke pneumonia (PSP) incidence, stroke subtype, severity, and prognosis. Material and Methods: Prospective observational study over a 42-month period in a Stroke Unit of a tertiary University Hospital. All patients with acute ischaemic stroke (AIS) were sequentially included. NLR was obtained at admission. Pa-tient characteristics such as stroke subtype, severity and PSP diagnosis were ascertained. Score A2DS2 was used as clinical predictor of PSP. Results: 521 patients with AIS were identified. The mean age was 76.17 ± 10.16 years years, 46.9% were men. Association was found between NLR and type and severity of stroke (p < 0.01), persisting in stratified analysis after excluding concomitant infection. Patients with higher ratio presented severer neurological deficits at admission, higher mortality, and dependency on discharge (p < 0.01). A logistic regression was performed to ascertain the predictive capacity of NLR (≥3) and A2DS2 (≥6) on the likelihood of developing PSP (p < 0.005). The model explained 17.1% (Nagelkerke R2) of the variance in pneumonia diagnoses, correctly classifying 77.0% of patients with 96.3% specificity. Patients with A2DS2 ≥6 were likelier to develop pneumonia (OR 8.36, p < 0.01). Moreover, patients with NLR ≥3 had higher odds of developing pneumonia (OR 2.35, p < 0.01). Conclusion: NLR appears to be related to severity in AIS, possibly as surrogate of neuroimmune mediation. Advances in the understanding of the immunobiological effects of ischemia in the brain may lead to future therapeutic developments. Presently, as a relatively inexpensive biomarker, there may be a potential role for NLR in improving PSP prediction scores.

Resumo Introdução: Avaliar a associação da relação neutrófilo-linfócito (NLR) e a incidência de pneumonia pós-acidente vascular cerebral (PSP), subtipo de acidente vascular cerebral (AVC), gravidade e prognóstico. Material e Métodos: Foi realizado um estudo prospetivo observacional durante um período de 42 meses numa Unidade de AVC de um hospital terciário. Todos os doentes com AVC isquémico agudo (AIS) foram sequencialmente incluídos. O valor de NLR foi calculado na admissão. As características dos doentes como subtipo de AVC, gravidade e diagnóstico de PSP foram obtidos. A escala A2DS2 foi utilizada como preditor clínico de PSP. Resultados: Foram identificados 521 doentes com AIS. A idade média foi 76,17 ± 10,16 anos, 46,9% eram homens. Verificou-se uma associação entre NLR, tipo e gravidade de AVC (p <0,01), persistindo em análise estratificada após exclu-são de infeção concomitante. Doentes com NLR mais elevado apresentavam défice neurológico mais grave na admissão, maior mortalidade e maior grau de dependência na alta (p < 0,01). Foi realizada uma regressão logística para caracterizar a capacidade preditiva da NLR (≥3) e do A2DS2 (≥6) na probabilidade de desenvolver PSP (p < 0,005). O modelo explicou 17,1% (Nagelkerke R2) da variância nos diagnósticos de pneumonia, classificando corretamente 77,0% dos doentes com uma especificidade de 96,3%. Doentes com A2DS2 ≥6 (OR 8,36, p < 0,01) e doentes com NLR ≥3 (OR 2,35, p < 0,01) apresentaram um maior risco de desenvolver pneumonia. Conclusão: NLR parece estar relacioando com a gravidade dos AIS, possivelmente como marcador de ativação neuroimune. Avanços na compreensão dos efeitos imunobiológicos da isquemia no cérebro poderão levar a desenvolvimentos terapêuticos futuros. Atualmente, sendo um biomarcador relativamente pouco dispendioso, talvez exista um papel da NLR na melhoria das escalas preditoras de PSP.

The waste resulting from marble extraction process is usually disposed of in landfills or dumps and its accumulation is causing serious environmental and landscaping problems. One way of reusing marble waste is to consider its incorporation in structural concrete as a non-primary aggregate. This research work attempts to alleviate the situation and provide information on the mechanical performance of concrete as a function of the replacement ratio of primary aggregates (PA) with coarse waste marble aggregates (CMA). Three concrete families, including reference concrete (RC) mixes, were studied that were made with primary aggregates of basalt (BCA), limestone (LCA) and granite (GCA) (these are the main sources of primary aggregates in the southern and central parts of Portugal), and concrete mixes with replacement ratios of 20%, 50% and 100% of PA by CMA. To evaluate their quality and mechanical performance mixes were tested for: slump (in the Abrams cone test), specific density, compressive strength, splitting tensile strength, Young's modulus of elasticity and resistance to abrasion. The results suggest a tendency for the values of all mechanical properties to decline. However, this tendency is clearly weaker than those observed for the majority of the research involving other types of non-primary recycled aggregates, which are already used in certain proportions in structural concrete, according to the limits imposed by the standards and specifications. The mechanical properties of concrete made with CMA were assessed within the scope of concurrent work also undertaken at Instituto Superior Técnico (Lisbon, Portugal), concerning the durability-related materials of the same type of concrete.