Incidence, diagnosis, management and outcome of acute mesenteric ischaemia: a prospective, multicentre observational study (AMESI Study)
Authors: Reintam Blaser Annika , Mändul Merli , Björck Martin , Acosta Stefan , Bala Miklosh , Bodnar Zsolt , Casian Dumitru , Demetrashvili Zaza , D’Oria Mario , Durán Muñoz-Cruzado Virginia , Forbes Alastair , Fuglseth Hanne , Hellerman Itzhaki Moran , Hess Benjamin , Kase Karri , Kirov Mikhail , Lein Kristoffer , Lindner Matthias , Loudet Cecilia Inés , Mole Damian J. , Murruste Marko , Nuzzo Alexandre , Saar Sten , Scheiterle Maximilian , Starkopf Joel , Talving Peep , Voomets Anna-Liisa , Voon Kenneth K. T. , Yunus Mohammad Alif , Tamme Kadri ,   AMESI Investigators (Collaborators), Corcos Olivier , Castier Yves , Ronot Maxime , Biloslavo Alan , Paiano Lucia , Elke Gunnar , Nagel Denise , Radke David I. , Vilca Becerra Jacqueline , Abeleyra María Elina , Cahenzli Martin , Semenkova Tatjana , Nikonov Anton , Smetkin Alexey , Nedredal Geir Ivar , Irtun Øivind , Cohen-Arazi Oded , Keda Asaf , Rojnoveanu Gheorghe , Ursu Alexandr , Ciuró Felipe Pareja , García-Leon Anabel , García-Sánchez Carlos Javier , Hui Lim Jia , Ling Loy Yuan , Kagan Ilya , Singer Pierre , Lipping Edgar , Tvaladze Ana , Damaskos Dimitrios , Clinch Darja , Qing Too Xiao , Vetrhus Morten , Martellucci Jacopo , Cerino Giulia , Hong Donghuang , Liu Jinsheng , Ong Ernest , Kundogan Kursat , Talih Tutkun , Bains Lovenish , Visconti Diego , Gibello Lorenzo , Jailani Ruhi Fadzlyana , Ashra Muhammad Amirul , Dzulkarnaen Zakaria Andee , Najmuddin Mohd Ghazi Ahmad Faiz , Abd Ghani Nur Suriyana , Ab Rahim Mohd Fadliyazid , Augustin Goran , Halužan Damir , Gurjar Mohan , Rahul Rahul , Hayati Firdaus , Mah Jin-Jiun 
Published: January 2024

Abstract
Background
The aim of this multicentre prospective observational study was to identify the incidence, patient characteristics, diagnostic pathway, management and outcome of acute mesenteric ischaemia (AMI).

Methods
All adult patients with clinical suspicion of AMI admitted or transferred to 32 participating hospitals from 06.06.2022 to 05.04.2023 were included. Participants who were subsequently shown not to have AMI or had localized intestinal gangrene due to strangulating bowel obstruction had only baseline and outcome data collected.

Results
AMI occurred in 0.038% of adult admissions in participating acute care hospitals worldwide. From a total of 705 included patients, 418 patients had confirmed AMI. In 69% AMI was the primary reason for admission, while in 31% AMI occurred after having been admitted with another diagnosis. Median time from onset of symptoms to hospital admission in patients admitted due to AMI was 24 h (interquartile range 9-48h) and time from admission to diagnosis was 6h (1–12 h). Occlusive arterial AMI was diagnosed in 231 (55.3%), venous in 73 (17.5%), non-occlusive (NOMI) in 55 (13.2%), other type in 11 (2.6%) and the subtype could not be classified in 48 (11.5%) patients. Surgery was the initial management in 242 (58%) patients, of which 59 (24.4%) underwent revascularization. Endovascular revascularization alone was carried out in 54 (13%), conservative treatment in 76 (18%) and palliative care in 46 (11%) patients. From patients with occlusive arterial AMI, revascularization was undertaken in 104 (45%), with 40 (38%) of them in one site admitting selected patients. Overall in-hospital and 90-day mortality of AMI was 49% and 53.3%, respectively, and among subtypes was lowest for venous AMI (13.7% and 16.4%) and highest for NOMI (72.7% and 74.5%). There was a high variability between participating sites for most variables studied.

Conclusions
The overall incidence of AMI and AMI subtypes varies worldwide, and case ascertainment is challenging. Pre-hospital delay in presentation was greater than delays after arriving at hospital. Surgery without revascularization was the most common management approach. Nearly half of the patients with AMI died during their index hospitalization. Together, these findings suggest a need for greater awareness of AMI, and better guidance in diagnosis and management.
Trial registration: NCT05218863 (registered 19.01.2022).