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©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
Ischemia/reperfusion injury in porcine intestine - Viability assessment
Runar J Strand-Amundsen, Henrik M Reims, Finn P Reinholt, Tom E Ruud, Runkuan Yang, Jan O Høgetveit, Tor I Tønnessen
Runar J Strand-Amundsen, Jan O Høgetveit, Department of Clinical and Biomedical Engineering, Oslo University Hospital, Oslo 0424, Norway
Runar J Strand-Amundsen, Jan O Høgetveit, Department of Physics, University of Oslo, Oslo 0316, Norway
Henrik M Reims, Finn P Reinholt, Department of Pathology, Oslo University Hospital, Oslo 0424, Norway
Tom E Ruud, Institute for Surgical Research, Oslo University Hospital, Oslo 0424, Norway
Tom E Ruud, Department of Surgery, Baerum Hospital, Vestre Viken Hospital Trust, Drammen 3004, Norway
Runkuan Yang, Tor I Tønnessen, Department of Emergencies and Critical Care, Oslo University Hospital, Oslo 0424, Norway
Tor I Tønnessen, Institute of Clinical Medicine, University of Oslo, Oslo 0424, Norway
Author contributions: Strand-Amundsen RJ, Yang R and Tønnessen TI performed the experiments, collected the histological samples and analyzed the microdialysis data; Reims HM and Reinholt FP analyzed, described and graded the histological samples; Strand-Amundsen RJ, Tønnessen TI, Ruud TE and Høgetveit JO designed and coordinated the research; Strand-Amundsen RJ wrote the paper with assistance and input from all the co-authors.
Supported by the Norwegian Research Council through the Integrisc project number 219819, and by Sensocure AS, Langmyra 11, 3185 Skoppum, Norway.
Institutional review board statement: The study was reviewed and approved by the Research and Development section at the Department of Clinical and Biomedical Engineering at the Oslo University Hospital.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Animal Ethics and Welfare Committee of Oslo University Hospital, and the Norwegian Food Authority (FOTS ID 8304 and 12695). The experiment was conducted in accordance with Norwegian animal welfare guidelines (FOR-2015-06-18-761) and EU directive (2010/63/EU).
Conflict-of-interest statement: The authors declare that they have no competing interests.
Data sharing statement: Readers can request the data of this paper by contacting us via runar.strand-amundsen@fys.uio.no.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Runar J Strand-Amundsen, MSc, Research Scientist, Department of Physics, University of Oslo, Postboks 1048 Blindern, Oslo 0316, Norway. runar.strand-amundsen@fys.uio.no
Telephone: +47-40029762
Received: March 9, 2018
Peer-review started: March 10, 2018
First decision: April 11, 2018
Revised: April 20, 2018
Accepted: April 23, 2018
Article in press: April 23, 2018
Published online: May 14, 2018
AIM
To investigate viability assessment of segmental small bowel ischemia/reperfusion in a porcine model.
METHODS
In 15 pigs, five or six 30-cm segments of jejunum were simultaneously made ischemic by clamping the mesenteric arteries and veins for 1 to 16 h. Reperfusion was initiated after different intervals of ischemia (1-8 h) and subsequently monitored for 5-15 h. The intestinal segments were regularly photographed and assessed visually and by palpation. Intraluminal lactate and glycerol concentrations were measured by microdialysis, and samples were collected for light microscopy and transmission electron microscopy. The histological changes were described and graded.
RESULTS
Using light microscopy, the jejunum was considered as viable until 6 h of ischemia, while with transmission electron microscopy the ischemic muscularis propria was considered viable until 5 h of ischemia. However, following ≥ 1 h of reperfusion, only segments that had been ischemic for ≤ 3 h appeared viable, suggesting a possible upper limit for viability in the porcine mesenteric occlusion model. Although intraluminal microdialysis allowed us to closely monitor the onset and duration of ischemia and the onset of reperfusion, we were unable to find sufficient level of association between tissue viability and metabolic markers to conclude that microdialysis is clinically relevant for viability assessment. Evaluation of color and motility appears to be poor indicators of intestinal viability.
CONCLUSION
Three hours of total ischemia of the small bowel followed by reperfusion appears to be the upper limit for viability in this porcine mesenteric ischemia model.
Core tip: Research on experimental methods to improve the surgeon’s assessment of viability of ischemic bowel with higher accuracy than currently possible, requires an accurate reference model. We investigated viability assessment in a porcine model of warm ischemia on jejunum with mesenteric occlusion, followed by reperfusion. Our aim was to determine the time point of irreversible damage, to provide a reference model. We created parallel segmental models on the jejunum in 15 pigs and compared the results from visual inspection with histology and microdialysis. Three hours of ischemia followed by reperfusion appeared to be the upper limit for viability in this model.
