Pre-operative ultrasound mapping before arteriovenous fistula formation: an updated systematic review and meta-analysis.

BACKGROUND: Arteriovenous fistula represents the preferred vascular access for patients with kidney failure requiring hemodialysis. Surgeons have traditionally used physical examination to identify the most suitable vessels. This meta-analysis aims to evaluate whether ultrasound mapping should be routinely performed before arteriovenous fistula creation. METHODS: Medline, Scopus, Web of Science and CENTRAL were systematically searched from inception to November 1, 2022. Randomized controlled trials and cohort studies comparing routine ultrasound mapping to physical examination in terms of arteriovenous fistula patency were included. Meta-analysis was performed by fitting random-effects models. The study protocol has been prospectively registered in PROSPERO (CRD42023402390). RESULTS: Overall, 18 studies were included, comprising 3655 participants. Routine pre-operative ultrasound mapping was associated with significantly lower rates of primary arteriovenous fistula failure (Risk Ratio-RR: 0.56, 95% confidence intervals-CI: 0.37-0.84, low certainty). A significant outcome was observed by separately pooling randomized controlled trials (RR: 0.37, 95% CI: 0.25-0.54). Routine ultrasound mapping was also associated with significantly higher rates of 1-year primary arteriovenous fistula patency (RR: 1.33, 95% CI: 1.19-1.47, moderate certainty). This effect remained significant in the analysis of randomized controlled trials (RR: 1.26, 95% CI: 1.02-1.56). CONCLUSIONS: Implementing routine pre-operative ultrasound mapping of vessels is associated with significantly better outcomes in terms of early arteriovenous fistula failure and primary patency rates at 12 months. Further research should confirm the long-term benefits of routine ultrasound examination and evaluate its cost-effectiveness in different populations.

Onodera's prognostic nutritional index: Comparison of its role in the severity and outcomes of patients with COVID­19 during the periods of alpha, delta and omicron variant predominance.

Coronavirus disease 2019 (COVID-19) has posed a severe public health threat worldwide, affecting the function of multiple organs in affected individuals, in addition to respiratory function. Several strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been circulating worldwide since it first arose, with some of these having the ability to escape from natural or vaccine-mediated immunity. The Onodera's prognostic nutritional index (OPNI), which is derived from the peripheral lymphocyte count and serum albumin, has been reported to be significantly associated with a poor survival rate and post-operative complications in patients with various diseases and in some studies on patients with COVID-19. The aim of the present retrospective study was to evaluate and compare the efficacy of OPNI as a prognostic indicator in patients with COVID-19 during the periods of alpha, delta and omicron variant predominance. Adult patients who visited or were hospitalized due to SARS-CoV-2 infection were included, covering the second, third (alpha variant), fourth (delta variant) and fifth (omicron variant) pandemic waves. According to the results obtained, OPNI exhibited a statistically significant difference among patients with mild/moderate, severe and critical disease, with the lowest values observed in patients with critical disease in all the pandemic waves examined. Moreover, OPNI was found to be an independent prognostic biomarker of intubation and mortality in patients with COVID-19, according to multivariate logistic regression analysis, including as confounders an age >65 years, the male sex and the presence of comorbidities in all periods examined.