Predictors of rupture and mortality in uncommon true visceral artery aneurysms: A protocol for a systematic review and pooled analysis.

Abstract

Background: Visceral artery aneurysms (VAAs) are rare vascular lesions associated with a substantial risk of rupture and high mortality. Splenic artery aneurysms (SAAs) are the most common and best studied, with relatively well-established risk factors and management strategies. In contrast, uncommon VAAs arising from the hepatic, celiac, superior mesenteric, gastroduodenal, pancreaticoduodenal, gastroepiploic, gastric, jejunal, ileal, colic, and inferior mesenteric arteries are exceedingly rare, and their natural history and rupture predictors remain poorly defined. Rupture has been reported at small diameters, challenging size-based thresholds derived largely from SAA data.

Objectives: This systematic review and pooled analysis aims to determine rupture rates, predictors of rupture, and rupture-related mortality of uncommon true VAAs, and to compare these outcomes with those reported for SAAs, which will serve as reference lesions.

Methods: The review will be conducted in accordance with PRISMA 2020 guidelines and is registered in PROSPERO (CRD420251155062). A comprehensive search of PubMed/MEDLINE, Embase, Web of Science, Scopus, and Google Scholar will be performed. For uncommon VAAs, eligible studies will include meta-analyses, systematic reviews, cohort studies, case series, and case reports. For SAAs, only meta-analyses, systematic reviews, and large cohort studies will be included. Pooled patient-level data will be extracted where available. Primary outcomes are rupture rate and rupture-related mortality; secondary outcomes include predictors of rupture according to aneurysm location, size, patient characteristics, and clinical presentation. Risk of bias will be assessed using JBI, ROBINS-I, and AMSTAR 2 tools.

Expected Impact: This review aims to clarify rupture behaviour of uncommon VAAs, identify clinically relevant predictors, and provide a stronger evidence base to support risk stratification and harmonisation of clinical decision-making.