Monthly access flow monitoring with increased prophylactic angioplasty did not improve fistula patency

BACKGROUND: Regular access monitoring is recommended to detect and treat access stenosis in order to prevent access thrombosis and failure. METHODS: In 1999, we instituted monthly access blood flow monitoring using the ultrasound dilution technique (UDT). In a sequential observational trial, 222 patients were studied for the impact of UDT monitoring on patency of their first arteriovenous autogenous fistula. Group 1, the historic group (before 1999), had 146 arteriovenous fistulas (50.7% upper arm), followed for 259 access-years. Group 2, the UDT-monitored group, had 76 arteriovenous fistulas (60.5% upper arm), followed for 123 access-years. Decision to refer for angiography was based on clinical criteria for group 1, and clinical criteria plus results of UDT flow monitoring in group 2. RESULTS: Cumulative patency was longer (P < 0.01) and the thrombosis rate was lower (P < 0.05) in group 2. However, the improvement occurred prior to initiation of UDT flow monitoring. Comparing outcomes in group 2 patients whose fistula survived to start flow monitoring with group 1 patients whose fistula survived at least 160 days (the median time to starting UDT monitoring in group 2), there was a sevenfold increase in angioplasty procedures (0.67 vs. 0.09 per access-year) but no improvement in the thrombosis rate or cumulative fistula patency. CONCLUSION: UDT monitoring increased the rate of angioplasty procedures and thereby shortened primary unassisted patency, but did not decrease the thrombosis rate or improve cumulative fistula patency.     

The Global Configuration of Visual Stimuli Alters Co-Fluctuations of Cross-Hemispheric Human Brain Activity

We tested how a stimulus gestalt, defined by the neuronal interaction between local and global features of a stimulus, is represented within human primary visual cortex (V1). We used high-resolution fMRI, which serves as a surrogate of neuronal activation, to measure co-fluctuations within subregions of V1 as (male and female) subjects were presented with peripheral stimuli, each with different global configurations. We found stronger cross-hemisphere correlations when fine-scale V1 cortical subregions represented parts of the same object compared with different objects. This result was consistent with the vertical bias in global processing and, critically, was independent of the task and local discontinuities within objects. Thus, despite the relatively small receptive fields of neurons within V1, global stimulus configuration affects neuronal processing via correlated fluctuations between regions that represent different sectors of the visual field.SIGNIFICANCE STATEMENT We provide the first evidence for the impact of global stimulus configuration on cross-hemispheric fMRI fluctuations, measured in human primary visual cortex. Our results are consistent with changes in the level of γ-band synchrony, which has been shown to be affected by global stimulus configuration, being reflected in the level fMRI co-fluctuations. These data help narrow the gap between knowledge of global stimulus configuration encoding at the single-neuron level versus at the behavioral level.     

Recommendations for Reopening Endoscopy Units in Turkey: A Set-up Plan from a Tertiary Center in Istanbul

In the midst of Coronavirus-19 (COVID-19) pandemic, endoscopic procedures have been separated for only urgent and semi-urgent cases for the last few months to prevent transmission in endoscopy units. This approach will perhaps resolve the burden of elective procedures in the months ahead of us. As we observe a downtrend in new cases of COVID-19 in Turkey, a strategy for reopening endoscopy units is required. We are stepping into a time period where we should not only re-provide the essential services to our patients but also maintain the safety of healthcare workers and preserve the valuable personal protective equipment as well. Herein, we aim to share the available knowledge in performing endoscopy during the pandemic and the set-up plan of a tertiary center in Istanbul for reopening the endoscopy unit in the era of the COVID-19 pandemic.     

Development of secondary T‐cell acute lymphoblastic leukemia in a child with hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a severe life‐threatening disorder, characterized by hyperactivation of macrophages. A 12‐year‐old female was referred to our center; the diagnosis of HLH was made for the patient and immunosuppressive regimen was started. After a 2‐year follow‐up, the patient developed secondary T‐cell acute lymphoblastic leukemia (T‐ALL), confirmed by flow cytometric studies. Treatment was started based on T‐ALL protocol, but the patient died because of relapse and sepsis. This case highlights the issue of secondary malignancy following HLH and demonstrates the need for continued follow‐up in such patients. Pediatr Blood Cancer. 2010;55:725–726. © 2010 Wiley‐Liss, Inc.     

COVID-19 outbreak and endoscopy: Considerations in patients encountered in a foregut surgery practice

Severe acute respiratory syndrome coronavirus has become a critical challenge to global health. Since the arrival of coronavirus disease 2019 in the United States,several government agencies and professional societies have issued guidelines to healthcare systems and medical providers. Endoscopy is a substantial portion of the practice of many general surgeons in the United States. With upper endoscopy, manipulation of the upper aerodigestive tract can turn the droplets to an aerosolized form and increase the likelihood of transmission and therefore is considered a high-risk procedure. In this article we review some aspects of the coronavirus disease 2019 outbreak that are relevant to practice of surgical endoscopy. The emphasis of this communication is on the mode of transmission,previous experiences during other coronavirus outbreaks and society guidelines.We then highlight the changes that we have made to our practice to incorporate these factors to improve the safety of patients, health care providers, and community as a whole.