Background The incidence of Acute Kidney Injury (AKI) and its human and economic cost is increasing steadily. One way to reduce the burden associated with AKI is to prevent the event altogether. An important step in prevention lies in AKI risk prediction. Due to the increasing number of available risk prediction models (RPMs) clinicians need to be able to rely on systematic reviews (SRs) to provide an objective assessment on which RPM can be used in a specific setting. Our aim was to assess the quality of SRs of RPMs in AKI. Methods The protocol for this overview was registered in PROSPERO. MEDLINE and Embase were searched for SRs of RPMs of AKI in any setting from 2003 till August 2020. We used the ROBIS tool to assess the methodological quality of the retrieved SRs. Results Eight SRs were retrieved. All studies were assessed as being at high risk for bias using the ROBIS tool. Eight reviews had a high risk of bias in study eligibility criteria (domain 1), five for study identification and selection (domain 2), seven for data collection and appraisal (domain 3) and seven for synthesis and findings (domain 4). Five reviews were scored at high risk of bias across all four domains. Risk of bias assessment with a formal risk of bias tool was only performed in five reviews. Primary studies were heterogeneous and used a wide range of AKI definitions. Only 19 unique RPM were externally validated, of which 11 had only 1 external validation report. Conclusion The methodological quality of SRs of RPMs of AKI is inconsistent. Most SRs lack a formal risk of bias assessment. SRs ought to adhere to certain standard quality criteria so that clinicians can rely on them to select a RPM for use in an individual patient. Trial registration PROSPERO registration number is CRD 42020204236, available at https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=204236.

We present a patient with an angiosarcoma in an arteriovenous fistula and we reviewed current treatments for angiosarcomas. We extended the systematic review by Oskrochi et al. on this topic in 2015, using the same search query. We searched systematically OVID, EMBASE and PubMed from April 2015 until January 2020 with the aim to update the state of the art in managing this rare but serious condition. We retrieved 12 new case reports about 11 unique patients. Mean age was 61.5 AE 11 years. Six arteriovenous fistulas had failed spontaneously. Two fistulas were operatively closed post-transplant. Nine patients (81.8%) were receiving ongoing immunosuppressive therapy. Pain and growing lesions, mass or swelling were the most frequent symptoms. Angiosarcoma mostly presents with a nonspecific clinical picture of pain, growing lesions and swelling of a previously normal arteriovenous fistula. Amputation of the limb was most frequently conducted as treatment in localized disease. Treatment of systemic disease included supportive care, chemotherapy, especially with paclitaxel and change of immunosuppressive regimen. Metastasized angiosarcoma has a very poor prognosis. Classical chemotherapy has rather low response rates. There is limited data supporting treatment of angiosarcomas with tyrosine kinase inhibitors or immunotherapy. Further comparative research is needed.