Bone Flap Necrosis After Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Infarction

Background

Autologous bone flap reinsertion follows as a second surgical intervention after decompressive craniectomy in patients with malignant middle cerebral artery (MCA) infarction. In addition to surgery-related short-term complications, aseptic resorption of the reimplanted bone flap is a possible long-term problem which has not yet been sufficiently elucidated in these patients.

Methods

A total of 109 patients who had undergone decompressive hemicraniectomy for malignant MCA infarction in our institution between September 1994 and December 2011 were included in the study. Clinical and radiological findings were retrieved retrospectively. Aseptic bone necrosis was classified into two categories based on computer tomographic features.

Results

A total of 76 patients received their own cryoconserved bone flap (mean age 54.34 ± 10.73 years; 49 males). The overall short-term complication rate was 9.2 %. Bone flap necrosis occurred in 26 patients (22.8 %) with 7 flaps showing signs of surgically relevant type II necrosis after a median time of 14 months (interquartile range [IQR] 4–22).

Conclusions

There is a noticeable complication rate in patients undergoing bone flap reinsertion after hemicraniectomy due to malignant MCA infarction. Aseptic bone necrosis represents a significant complication during long-term follow-up. The pathophysiological mechanisms remain unclear and more efforts should be undertaken to understand and possibly prevent this complication in these patients.     

Integration of PET-imaging into radiotherapy treatment planning for low-grade meningiomas improves outcome

European Journal of Nuclear Medicine and Molecular Imaging - Meningiomas have an excellent survival prognosis, and radiotherapy (RT) is a central component of interdisciplinary treatment. During...     

Neighborhood Ethnic Composition,Spatial Assimilation,and Change in Body Mass Index Over Time Among Hispanic and Chinese Immigrants: Multi-Ethnic Study of Atherosclerosis

Objectives. We investigated relations between changes in neighborhood ethnic composition and changes in body mass index (BMI) and waist circumference among Chinese and Hispanic immigrants in the United States.Methods. We used Multi-Ethnic Study of Atherosclerosis data over a median 9-year follow-up (2000–2002 to 2010–2012) among Chinese (n = 642) and Hispanic (n = 784) immigrants aged 45 to 84 years at baseline. We incorporated information about residential moves and used econometric fixed-effects models to control for confounding by time-invariant characteristics. We characterized neighborhood racial/ethnic composition with census tract–level percentage Asian for Chinese participants and percentage Hispanic for Hispanic participants (neighborhood coethnic concentration).Results. In covariate-adjusted longitudinal fixed-effects models, results suggested associations between decreasing neighborhood coethnic concentration and increasing weight, although results were imprecise: within-person BMI increases associated with an interquartile range decrease in coethnic concentration were 0.15 kilograms per meters squared (95% confidence interval [CI] = 0.00, 0.30) among Chinese and 0.17 kilograms per meters squared (95% CI = –0.17, 0.51) among Hispanic participants. Results did not differ between those who did and did not move during follow-up.Conclusions. Residential neighborhoods may help shape chronic disease risk among immigrants.More than 40 million immigrants reside in the United States, 81% of whom emigrated from Latin America or Asia.1 Not only is the US foreign-born population increasing, but also is the proportion of immigrants who have resided in the United States for a long period of time. An estimated 39% of immigrants had resided in the United States for 20 years or more as of 2010, and this proportion is projected to surpass 50% by 2030.2 This demographic shift has important ramifications for population health and the health service burden because, among immigrants, both cardiovascular disease (CVD) risk and weight, a key CVD risk factor, tend to increase with longer length of stay in the United States, above and beyond the influence of age.3–7Although explanations for immigrant health patterns often focus on how individual-level health behaviors change across time to align with those of the receiving US culture,5 broader factors may also be important. For example, the neighborhoods in which immigrants reside may contribute to weight changes associated with tenure in the United States. Recent immigrants tend to initially settle in immigrant enclaves, neighborhoods with large numbers of other immigrants of the same country of origin or ethnicity (high coethnic concentration). However, over time, many immigrants move out of immigrant enclaves to neighborhoods with lower proportions of other coethnics or immigrants.8 Classical sociological spatial assimilation theory posits that this process of residential spatial assimilation serves as one important dimension of assimilation into the dominant US culture.8–10 Although the theory does not explicitly state how health would be affected, it implies changes in exposures to neighborhood-level social and physical characteristics that could influence health.Weight-related physical and social resources in neighborhoods with large immigrant populations may differ from those with fewer immigrants.9,11–13 For example, businesses in immigrant enclaves often provide services or products specific to their ethnic market, including food stores.9,12 Empirical findings on whether the food environment in immigrant enclaves is healthier than in other neighborhoods are inconsistent. Higher neighborhood proportions of Hispanic and Asian residents have been associated with higher numbers of convenience stores and fast-food restaurants—sources of unhealthy foods—but also with higher numbers of nonchain supermarkets and grocery stores, which may contribute to a healthier and more culturally appropriate food environment.14–16 Chinese and Hispanic participants living in immigrant enclaves have reported better availability of healthy food than participants living in other neighborhoods.13 Other aspects of the built environment that are relevant to weight, such as how conducive to walking it is, may also vary by neighborhood ethnic composition.13 Aside from physical resources, the presence of other immigrants in a neighborhood may provide psychosocial benefits by buffering residents against discrimination or by providing access to larger social networks,11,17 but the empirical evidence is again inconsistent.13 These neighborhood differences may in turn affect behavioral and psychosocial determinants of weight.18–23 For example, higher immigrant and ethnic concentration has been associated with differences in diet and physical activity,13,24–27 as well as with better mental health and less perceived discrimination,17,28–35 all of which could have an impact on weight.Few studies have examined associations between neighborhood ethnic composition and weight among immigrants.36–41 Results have varied depending on the immigrant group examined or the composition measure used (e.g., percentage foreign-born, percentage Hispanic).36–39 Moreover, the majority of previous evidence is cross-sectional and cannot investigate patterns of residential mobility, including spatial assimilation, that may affect weight over time.42 Longitudinal studies are therefore crucial for understanding how neighborhood context may affect weight over time in immigrants.3 Despite substantial theoretical and empirical sociological research dedicated to characterizing residential patterns among immigrants, there is little research in either sociology or public health that explicitly examines the implications of these patterns for health.We used longitudinal econometric fixed-effects models to investigate whether changes in neighborhood ethnic composition were related to changes in body mass index (BMI; defined as weight in kilograms divided by the square of height in meters) and waist circumference (WC) over a median follow-up of 9 years among a cohort of Chinese and Hispanic immigrants in the United States. Because fixed-effects models rely only on intraindividual variability, and therefore tightly control for all time-invariant individual-level characteristics, this approach can reduce the likelihood that observed results are confounded.43 We hypothesized that decreases in neighborhood coethnic concentration would be related to increases in BMI and WC in our sample. We also hypothesized that immigrants who spatially assimilated during follow-up (i.e., who moved to a neighborhood with lower coethnic concentration, as opposed to staying in the same residence with their neighborhood changing around them) would experience greater increases in BMI and WC. Our second hypothesis was driven by the idea that, consistent with classical spatial assimilation theory, spatial assimilation may denote a greater likelihood of adopting less healthy behaviors associated with the dominant US culture.     

Non-small Cell Lung Cancer Treatment Receipt and Survival Among African-Americans and Whites in a Rural Area

Data on racial disparities among lung cancer patients in rural areas are scarce. We examined differences in treatment receipt and survival among African-American (AA) and Non-Hispanic White (NHW) non-small cell lung cancer (NSCLC) patients residing in Southwest Georgia (SWGA)—a primarily rural 33-county area; population 700,000. Medical records for 934 SWGA NSCLC patients diagnosed in 2001–2003 were used to extract information on age, race, marital status, insurance coverage, comorbidities, and treatment. Information pertaining to socioeconomic status, urban/rural residence, and survival was obtained from the cancer registry. Multivariable logistic regression analyses examined the relation of various patient and disease characteristics to receipt of tumor-directed therapy. Cox regression models were used to assess determinants of survival. Treatment receipt was associated with age, marital status, comorbidities, and disease stage in most analyses. No associations were observed between race and either surgery [odds ratio (OR) 0.83, 95 % confidence interval (CI) 0.49–1.39] or radiation (OR 0.72; 95 % CI 0.52–1.00). NHW patients were more likely to receive no treatment at all (OR 1.50, 95 % CI 1.01–2.23). There was no racial difference in survival (hazard ratio = 1.07, 95 % CI 0.90–1.26). Effects of insurance and treatment on survival were most pronounced within 6 months post-diagnosis, but were attenuated over time. We found no evidence of racial disparities in survival and, in some analyses, a decreased likelihood of treatment receipt among NHW NSCLC patients compared to AA. The results from SWGA stand in contrast to studies that applied different methodologies and were conducted elsewhere.     

Antimicrobial treatment options for neurosurgical ventricular shunt infections in children from 1993 to 2012: a systematic review

Purpose

The aim of this systematic review was to review studies that existed from 1993 to 2012 regarding antimicrobial treatment options of paediatric neurosurgical shunt.

Methods

Studies were identified from MEDLINE, Scopus and Cochrane databases using a search strategy that was registered on the PROSPERO database. Studies were included if they had two or more patients, aged less than 18 years, and also specified the organism and antimicrobial treatment that was used.

Results

The search yielded 2,985 articles, and 76 articles were suitable for full review. In the final qualitative analysis, only eight studies were included, involving 86 participants. The most common antimicrobial regimens for Gram-positive infections was intravenous and intrathecal vancomycin (n?=?7), followed by intravenous vancomycin monotherapy.

Conclusion

This systematic review has shown that there are no prospective randomised studies of antimicrobial treatment options for paediatric neurosurgical patients in the last 20 years, and larger prospective studies are urgently required for this serious infection. There is some limited case series showing the benefits of certain antimicrobials such as vancomycin and ceftriaxone, but a larger case series or randomised controlled trial is required, particularly to establish the benefit, if any, of additional intraventricular antimicrobials.     

Diagnosing skin rejection in vascularized composite allotransplantation: advances and challenges

Refinements in microsurgical techniques coupled with advances in immunosuppressive and immunomodulatory protocols have enabled broader clinical application of vascularized composite allotransplantation (VCA) with encouraging immunological, functional, and esthetic results. However, skin rejection remains a significant obstacle and a serious complication for VCA recipients. Clinical and histopathological features of rejection in VCA have been described in a number of studies, which led to the development of an international consensus on the classification guidelines of rejection in the context of VCA. Nevertheless, currently available diagnostic modalities still have several limitations and shortcomings that can pose a significant diagnostic challenge, particularly when signs of rejection are found to be equivocal. In this review, we provide a critical analysis of these advances and challenges in diagnosing skin rejection. Specifically, we highlight the gaps in understanding of rejection mechanisms, the shortfalls in correlating cellular, molecular, and clinicopathologic markers with rejection grades, deficiencies in defining chronic rejection, and antibody‐mediated rejection after VCA, as well as providing an outlook on novel concepts, such as the utilization of advanced computational analyses and cross‐disciplinary diagnostic approaches.     

Biology of sepsis: Its relevance to pediatric nephrology

Because of its multi-organ involvement, the syndrome of sepsis provides clinical challenges to a wide variety of health care providers. While multi-organ dysfunction triggered by sepsis requires general supportive critical care provided by intensivists, the impact of sepsis on renal function and the ability of renal replacement therapies to modulate its biologic consequences provide a significant opportunity for pediatric nephrologists and related care providers to impact outcomes. In this review, we aim to highlight newer areas of understanding of the pathobiology of sepsis with special emphasis on those aspects of particular interest to pediatric nephrology. As such, we aim to: (1) review the definition of sepsis and discuss advances in our mechanistic understanding of sepsis; (2) review current hypotheses regarding sepsis-induced acute kidney injury (AKI) and describe its epidemiology based on evolving definitions of AKI; (3) review the impact of renal failure on the immune system, highlighting the sepsis risk in this cohort and strategies that might minimize this risk; (4) review how renal replacement therapeutic strategies may impact sepsis-induced AKI outcomes. By focusing the review on these specific areas, we have omitted other important areas of the biology of sepsis and additional interactions with renal function from this discussion; however, we have aimed to provide a comprehensive list of references that provide contemporary reviews of these additional areas.     

Evaluation of safety and efficacy as an adjuvant for the chitosan-based vaccine delivery vehicle ViscoGel in a single-blind randomised Phase I/IIa clinical trial

ViscoGel, a chitosan-based hydrogel, has earlier been shown to improve humoral and cell-mediated immune responses in mice. In this study, a Phase I/IIa clinical trial was conducted to primarily evaluate safety and secondarily to study the effects of ViscoGel in combination with a model vaccine, Act-HIB to Haemophilus influenzae type b, administered as a single intramuscular injection. Healthy volunteers of both sexes, ages 22–50 and not previously vaccinated to HIB, were recruited. The trial had two phases. In Phase A, three ascending dose levels of ViscoGel (25, 50 and 75 mg) were evaluated for safety in 3 × 10 subjects. Phase B had a single-blind, randomised, parallel-group design evaluating safety and efficacy in five groups, 20 subjects/group, comparing vaccination with 0.2 μg or 2 μg Act-HIB alone or combined with ViscoGel (50 mg) and one group receiving the standard Act-HIB dose (10 μg). No safety or tolerability concerns were identified. Local, transient reactions at the injection site were the most common adverse events. These were more frequent in groups receiving Act-HIB + ViscoGel, while other AEs were recorded at similar frequency in Act-HIB and Act-HIB + ViscoGel groups. Efficacy was evaluated by measuring serum anti-HIB antibodies and cellular responses in peripheral blood mononuclear cells (PBMC). There was a large variation in baseline anti-HIB antibody titres and no adjuvant effect was observed on the anti-HIB antibody production in groups vaccinated with Act-HIB + ViscoGel. ELISpot analyses revealed increased interferon-γ (IFN-γ) responses to Act-HIB in PBMCs from subjects vaccinated with Act-HIB in combination with ViscoGel, compared to groups receiving Act-HIB alone. Moreover, ViscoGel counteracted an inhibitory effect of Act-HIB vaccination on the IFN-γ response to both the vaccine itself and an irrelevant influenza antigen. In summary, ViscoGel was found to be safe and well-tolerated, supporting further examination of ViscoGel as a new innovative vehicle for vaccine development.