International multidisciplinary consensus on the definition and nomenclature of acute mesenteric ischaemia: a modified Delphi study
Year: 2026
Type: article
Abstract: Acute mesenteric ischaemia (AMI) is a life-threatening emergency with in-hospital mortality of 49–64% across recent cohort studies. Terminology and nomenclature for acute ischaemia of the gastrointestinal tract remain inconsistent across disciplines and geographies, hindering clinical communication, registry design, and research comparability. This project aimed to develop consensus definitions and clinical algorithms for AMI; the present paper addresses definitions and nomenclature, and the companion paper the algorithms. A seven-member steering committee representing intensive care, vascular surgery, general surgery, interventional radiology, and gastroenterology conducted a literature review (2020–2025) and drafted candidate definition statements. An international panel of 50 experts from 15 countries underwent a modified Delphi process comprising two electronic voting rounds (9-point GRADE scale; predefined consensus threshold: ≥75% rated 7–9 and ≤ 15% rated 1–3) via REDCap, followed by two virtual consensus meetings with live polling. Where clinical equipoise existed, competing statements were presented for independent rating. Fifty panellists completed Round 1 (22 statements) and 44 completed Round 2 (27 statements; retention 88%). Ten statements reached the predefined electronic consensus threshold, including a core AMI definition (100%), mechanism classification (100%), and subtype definitions for arterial occlusive AMI (91%), venous AMI (84%), and non-occlusive mesenteric ischaemia (NOMI; 86%). The consensus meetings adopted a novel two-tier nomenclature: Acute GastroIntestinal Ischaemia (AGII) as the umbrella term for acute ischaemia of the gastrointestinal tract, and AMI as the subset to which the clinical algorithms apply. ‘Ischaemic colitis’ was declared a misnomer (92%). The arterial territory question (superior mesenteric artery (SMA) only versus a broader mesenteric territory) was not resolved and is presented as a dual-interpretation framework. Subgroup analysis revealed a specialty-driven divergence: general (73%, n = 11) and vascular surgeons (67%, n = 9) favoured restricting AMI to the SMA distribution, whereas intensivists favoured the whole gastrointestinal tract (80%, n = 10). This international, multidisciplinary Delphi study provides consensus definitions of AMI and its subtypes and proposes AGII/AMI as a two-tier nomenclature to resolve longstanding territorial and terminological ambiguities. These definitions lay the foundation for the companion clinical algorithms and aim to provide a standardised framework for future research, clinical communication, and registry design.
Authors: Annika Reintam Blaser, Stefan Acosta, Dumitru Casian, Miklosh Bala, Lorenzo Garzelli, Loris Pironi, Walter L. Biffl, Alan Biloslavo, Martin Björck, Paul Calame, Juan Antonio Celi de la Torre, Tommaso D’Angelo, Dimitrios Damaskos, Sameh H. Emile, Alastair Forbes, Benjamin Hess, Jussi M. Kärkkäinen, Mark J.W. Koelemay, Inès Lakbar, Romaric Loffroy, Diane Mege, Vladislav Mihnovitš, Marko Murruste, Alexandre Nuzzo, Martin Padar, Simone Piva, Francesca Rigiroli, Maxime Ronot, Ville Sallinen, Beat Schnüriger, Klaus Stahl, Joel Starkopf, Toru Takiguchi, Kadri Tamme, Matti Tolonen, Christopher P. Twine, Tim Vanuytsel, Diego Visconti, Todd R. Vogel, Wenhan Wu, Sara L. Zettervall, Kaspar F. Bachmann
Institutions: Luzerner Kantonsspital, University of Tartu, Lund University, Institutul Medicina de Urgenta, Nicolae Testemițanu State University of Medicine and Pharmacy, Hebrew University of Jerusalem, Sorbonne Université, Hôpital Saint-Antoine, University of Bologna, Scripps Memorial Hospital, Ospedale di Cattinara, Uppsala University, Centre Hospitalier Universitaire de Besançon, Soins intégrés, Nanomédecine, IA & Ingénierie pour la Santé, Université Marie et Louis Pasteur, University of Messina, Edinburgh Royal Infirmary, Mansoura University, Mansoura University Hospital, Cleveland Clinic Florida, Turku University Hospital, Amsterdam University Medical Centers, Centre Hospitalier Universitaire de Montpellier, CHU Dijon Bourgogne, Université Bourgogne Europe, Aix-Marseille Université, Hôpital de la Timone, Tartu University Hospital, Inserm, Université Paris Cité, Hôpital Beaujon, Laboratoire de Recherche Vasculaire Translationnelle, Hôpital Bichat-Claude-Bernard, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, University of Brescia, Lahey Hospital and Medical Center, University of Massachusetts Chan Medical School, Assistance Publique – Hôpitaux de Paris, Centre de Recherche sur l'Inflammation, University of Helsinki, Helsinki University Hospital, University Hospital of Bern, Medizinische Hochschule Hannover, University of Tokyo Hospital, Nippon Medical School Hospital, Nippon Medical School, University of Bristol, Bristol NHS Foundation Trust, Universitair Ziekenhuis Leuven, Azienda Ospedaliera Citta' della Salute e della Scienza di Torino, University of Missouri, The Affiliated Yongchuan Hospital of Chongqing Medical University, University of Washington, University Hospital of Basel
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,990
Funder: Eesti Teadusagentuur
OpenAlex ID: W7225408643