Dataset Information

Multicentre randomised controlled trial to evaluate the efficacy of pre-emptive inferior mesenteric artery embolisation during endovascular aortic aneurysm repair on aneurysm sac change: protocol of Clarify IMA study.

ABSTRACT:

Introduction

Type II endoleak (EL) is frequently seen after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) and is often considered responsible for aneurysm sac enlargement if it persists. In order to reduce type II EL and consequent sac enlargement, pre-emptive embolisation of the inferior mesenteric artery (IMA), which is a main source for persistent type II EL, has been introduced in many vascular centres. At present, there is a lack of robust evidence to support the efficacy of pre-emptive embolisation of IMA on reduction of persistent type II EL with subsequent sac shrinkage.

Method and analysis

This multicentre, randomised controlled trial will recruit 200 patients who have fusiform AAA ≥50 mm/rapidly enlarging fusiform AAA, with patent IMA, and randomly allocate them either to a pre-emptive IMA embolisation group or non-embolisation control group in a ratio of 1:1. The primary endpoint is the difference of aneurysm sac volume change assessed by CT scans between the pre-emptive IMA embolisation group and the control group at 12 months after EVAR. The secondary endpoints are defined as change of aneurysm sac volume in both groups at 6 and 24 months, freedom from sac enlargement at 12 and 24 months after EVAR, prevalence of type II EL at 1, 6, 12 and 24 months evaluated by contrast-enhanced CT, reintervention rate, aneurysm related mortality, overall survival, perioperative morbidity, volume of contrast media used during EVAR and dosage of radiation.

Ethics and dissemination

The protocol has been reviewed and approved by the ethics committee of Nara Medical University (No. 2113). The findings of this study will be communicated to healthcare professionals, participants and the public through peer-reviewed publications, scientific conferences and the University Hospital Medical Information Network Clinical Trials Registry home page.

Trial registration number

UMIN000035502.

SUBMITTER: Ichihashi S

PROVIDER: S-EPMC7044938 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ObjectivePrevious reports have revealed a high incidence of type II endoleak (T2EL) after endovascular aneurysm repair (EVAR). The incidence of T2EL after EVAR is reduced by pre-emptive embolization of aneurysm sac side branches (ASSB) and aneurysm sac coil embolization (ASCE). This study aimed to investigate whether different preventive interventions for T2EL were correlated with suppression of aneurysm sac expansion and reduction of the re-intervention rate.MethodsThe PubMed, Web of Science, MEDLINE and Embase databases, and conference proceedings were searched to identify articles on EVAR with or without embolization. The study was developed in line with the Participants, Interventions, Comparisons, Outcomes, and Study design principles and was conducted and reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We used network meta-analysis based on multivariate random-effects meta-analysis to indirectly compare outcomes of different strategies for embolization during EVAR.ResultsA total of 31 studies met all inclusion criteria and were included in the qualitative and quantitative syntheses. The included studies were published between 2001 and 2022 and analyzed a total of 18,542 patients, including 1,882 patients who received prophylactic embolization treatment during EVAR (experimental group) and 16,660 who did not receive prophylactic embolization during EVAR (control group). The effect of pre-emptive embolization of the inferior mesenteric artery (IMA) (IMA-ASSB) in preventing T2EL was similar (relative risk [RR] 1.01, 95% confidence interval [CI] 0.38-2.63) to the effects of non-selective embolization of ASSB (NS-ASSB) and ASCE (RR 0.88, 95% CI 0.40-1.96). IMA-ASSB showed a better clinical effect in suppressing the aneurysm sac expansion (RR 0.27, 95% CI 0.09-2.25 compared with NS-ASSB; RR 0.93, 95% CI 0.16-5.56 compared with ASCE) and reducing the re-intervention rate (RR 0.34, 95% CI 0.08-1.53 compared with NS-ASSB; RR 0.66, 95% CI 0.19-2.22 compared with ASCE). All prophylactic embolization strategies improved the clinical outcomes of EVAR.ConclusionProphylactic embolization during EVAR effectively prevents T2EL, suppresses the aneurysm sac expansion, and reduces the re-intervention rate. IMA embolization demonstrated benefits in achieving long-term aneurysm sac stability and lowering the risk of secondary surgery. NS-ASSB more effectively reduces the incidence of T2EL, while IMA embolization alone or in combination with ASCE enhances the clinical benefits of EVAR. In addition, as network meta-analysis is still an indirect method based on a refinement of existing data, more studies and evidence are still needed in the future to establish more credible conclusions.

Project description:ObjectivesOur goal was to identify the inferior mesenteric artery diameter and number of patent lumbar arteries causing a significant type 2 endoleak to develop after infrarenal endovascular aneurysm repair.Material and methodsIncluded were patients who underwent infrarenal endovascular aneurysm repair between April 2002 and January 2017. Patients with an aneurysm involving the iliac arteries were excluded. Significant type 2 endoleak was defined as a type 2 endoleak observed after infrarenal endovascular aneurysm repair and accompanied by abdominal aneurysm growth of at least 5 mm during that time.ResultsA total of 277 patients were included. Mean follow-up was 38.9 (standard deviation 121.6) months. Immediately after infrarenal endovascular aneurysm repair, type 2 endoleaks occurred in 55 patients (20%), resolving spontaneously in 2 patients 6 months after infrarenal endovascular aneurysm repair. Thirty (10.8%) patients revealed a significant type 2 endoleak with aneurysm sack enlargement > 5 mm during follow-up, for which inferior mesenteric artery or lumbar artery coiling was performed. Mean time for coiling after primary infrarenal endovascular aneurysm repair was 25.4 (standard deviation 19.10) months. Twenty-three patients (8.3%) showed a non-significant type 2 endoleak during follow-up (no aneurysm sack enlargement). We found that the inferior mesenteric artery diameter and number of patent lumbar arteries were factors associated with a significant type 2 endoleak (odds ratio 1.755, P = 0.001; odds ratio 1.717, P < 0.001, respectively). Prior to endovascular aneurysm repair, the inferior mesenteric artery was patent in 212 (76.5%) patients; its median diameter measured 3 (0.5-3.8) mm. The median number of patent lumbar arteries was 3 (2-4). According to our receiver operating characteristic curve analysis, an inferior mesenteric artery diameter ≥3 mm (sensitivity 93.3%, specificity 65%) and ≥3 patent lumbar arteries (sensitivity 87.5%, specificity 43.6%) proved to be optimal cut-off values related to developing a significant type 2 endoleak. We therefore propose a composite score for the development of a significant type 2 endoleak [(inferior mesenteric artery diameter + patent lumbar arteries)/2].ConclusionsPatients in whom the diameter of the inferior mesenteric artery is ≥ 3 mm and with ≥ 3 patent lumbar arteries carry a higher risk of developing significant type 2 endoleak after infrarenal endovascular aneurysm repair.

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