Liguori et al. BMC Urol (2021) 21:104 https://doi.org/10.1186/s12894-021-00873-w RESEARCH ARTICLE Open Access The role of angioembolization in the management of blunt renal injuries: a systematic review Giovanni Liguori1, Giacomo Rebez1* , Alessandro Larcher2, Michele Rizzo1, Tommaso Cai3 and Carlo Trombetta and Andrea Salonia2 Abstract Background: Recently, renal angioembolization (RAE) has gained an important role in the non-operative manage- ment (NOM) of moderate to high-grade blunt renal injuries (BRI), but its use remains heterogeneous. The aim of this review is to examine the current literature on indications and outcomes of angioembolization in BRI. Methods: We conducted a search of MEDLINE, EMBASE, SCOPUS and Web of Science Databases up to February 2021 in accordance with PRISMA guidelines for studies on BRI treated with RAE. The methodological quality of eligible stud- ies and their risk of bias was assessed using the Newcastle–Ottawa scale Results: A total of 16 articles that investigated angioembolization of blunt renal injury were included in the study. Overall, 412 patients were included: 8 presented with grade II renal trauma (2%), 97 with grade III renal trauma (23%); 225 with grade IV (55%); and 82 with grade V (20%). RAE was successful in 92% of grade III–IV (294/322) and 76% of grade V (63/82). Regarding haemodynamic status, success rate was achieved in 90% (312/346) of stable patients, but only in 63% (42/66) of unstable patients. The most common indication for RAE was active contrast extravasation in hemodynamic stable patients with grade III or IV BRI. Conclusions: This is the first review assessing outcomes and indication of angioembolization in blunt renal injuries. The results suggest that outcomes are excellent in hemodynamic stable, moderate to high-grade renal trauma. Keywords: Renal, Blunt, Angioembolization, Trauma, Kidney Key points robust enough to support angioembolization as a standard of care in these subgroups. Angioembolization is effective and safe in stable grade III–IV blunt renal trauma. Grade I–II blunt renal injuries need RAE very occa- sionally. Introduction A few hemodynamically unstable and or grade V Renal angioembolization (RAE) is an effective, mini- patients might benefit from RAE but the data is not mally invasive treatment that was first developed in the 1970s [1]. Renal injuries occur in approximately 10% of all abdominal trauma [2] and the kidney is the third most *Correspondence: [email protected] commonly injured solid organ. Every year, up to 245.000 1 Azienda Sanitaria Universitaria Giuliano-Isontina, Strada di Fiume 447, renal injuries occur worldwide; blunt trauma is responsi- 34149 Trieste, Italy Full list of author information is available at the end of the article ble for 80–90% of them [2, 3]. 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The Creative Commons Public Domain Dedication waiver (http:// creat iveco mmons. org/ publi cdoma in/ zero/1. 0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Liguori et al. BMC Urol (2021) 21:104 Page 2 of 8 non-operative management (NOM), including observa- publications; (3) studies involving angioembolization tion, transfusion, bed rest and/or renal angiography with of open injury, penetrating trauma, paediatric patients embolization (RAE), has become increasingly popular, or iatrogenic injury; and (4) studies with insufficient or especially for low-grade (I–II) and intermediate grade unconfirmed information. (III) blunt renal injuries (BRI). High-grade renal trauma Preferred Reporting Items for Systematic Review and has traditionally been managed via surgical explora- Meta-Analysis (PRISMA) guidelines were followed to tion and published evidence is unclear about the role of perform this review. "e titles were screened to evalu- NOM for higher grades (IV and V) [4–6]. Over the last ate whether they met the inclusion criteria. "ese stud- few decades, the management of patients with multiple ies were divided into three different categories: included, injuries has improved thanks to specialized trauma units probably relevant and excluded. Included and relevant and NOM has become the treatment of choice for most studies were re-evaluated to check eligibility. renal injuries [7]. Hemodynamic stability is one of the most important criteria to decide between operative and Data extraction and quality assessment non-operative strategies in renal injuries [8]. As a whole, Data including the first author, publication year, num- primary conservative management is associated with ber of patients, age, sex, indications, materials, and a lower rate of nephrectomies, without increasing the outcome of interest were extracted by two autonomous immediate or long-term morbidity. "e improved stag- reviewers into standardized MS Office Excel. "e risk ing of injury severity, thanks to advancing radiographic of bias and the methodological quality of eligible stud- techniques, has enhanced the use of NOM [9]. Further- ies were assessed using the Newcastle–Ottawa scale more, selective treatment with interventional radiology [14] which weighs nine items across the domains of procedures has eventually reduced the need for surgical selection, comparability and outcome for cohort stud- interventions in patients with both blunt and penetrat- ies. Each of these three items was assessed and graded ing renal injuries [9, 10]. Hemodynamic stability is one of (1 or 2 points). In this analysis, studies with NOS scores the most important criteria to decide between operative of 1–3, 4–6, and 7–9, were defined as of low, interme- and non-operative strategies in renal injuries [8] Angi- diate, and high quality, respectively. Poor quality stud- oembolization has an important role in the management ies were not excluded from the review. Two authors of high-grade BRI [11, 12] but currently, its use remains independently extracted the data and gave each study heterogeneous. "e aim of this review is to evaluate the a quality assessment; any discordances were resolved efficacy of angioembolization in blunt renal trauma in through discussion to reach an agreement. current literature, with the aim of understanding the indications and outcomes of RAE in patients with mod- Results erate- to high grade renal trauma. Using these search criteria, an initial selection of 1057 articles was considered. After title screening and man- Methods ual reduplication, we narrowed down to 943 eligible for PRISMA guidelines [13] were followed, and a literature abstract review. Full-text evaluation for the remaining search was performed using PUBMED, EMBASE, SCO- 131 citations identified by abstract review or by a manual PUS, Web of Science. Articles either published or e-pub- search of the references list was done (Fig. 1). A total of lished on angioembolization for BRI between January 16 articles that investigated angioembolization in blunt 2009 and February 2021 were searched. "e Mesh terms renal injury were included in the study. used for the search were: “renal” (“kidney”); “trauma” (“injury”); “embolization”; “angiography”; (“Renal Angio Quality assessment of the included studies Embolization” or “RAE”). An additional manual search Most studies (68.7%) were graded as intermediate or high of EMBASE, as well as bibliographies of each included quality and full details of the NOS quality appraisal score study, was done to identify studies not covered by the ini- for each study are summarized in the Additional file 1: tial search. Table S1 Quality assessment using the modified New- castle-Ottawa scale of included cohort studies. Selec- Study eligibility tion and confounding were important sources of error, Studies were selected on the following criteria: (1) with only 2 (12.5%) studies attaining the maximum score patients age > 18 years; (2) studies reporting outcomes of for selection and no study reaching the maximum score upfront RAE; (3) English language; (4) studies reporting for comparability; 31.2% of cohort designs scored 3/3 indications, techniques and/or embolic materials. "e for outcome measurement. No prospective studies were exclusion criteria were as follows: (1) reviews or editor available in the current literature. letters and single case report; (2) non-English language Liguori et al. BMC Urol (2021) 21:104 Page 3 of 8 on Records idenfied through EMBASE Addional records idenfied (n = 1050) through PUBMED fica (n =996) Iden Recordsa er duplicates removed (n = 943) g Screenin Recordsscreened Records excluded (n = 943) (n = 812) Full-text arcles assessed Full-text arcles excluded, y for eligibility with reasons it il (n =131) (n =115) 75: irrelevant to the main subject Eligib 23: