BACKGROUND/AIMS: The functional lumen imaging probe (FLIP) relies on the principle of impedance planimetry that enables direct measurement of intraluminal pressure, cross-sectional areas, and wall biomechanical properties. The aim of our pilot project was to introduce this method to assess function of the lower oesophageal sphincter and pyloric muscle in experimental pigs. METHODS: All measurements were accomplished in one session in six adult female pigs (mean weight 34.2 ± 3.6 kg), using the EndoFLIP 1.0 System with EndoFLIP catheters. Five major parameters were evaluated: balloon pressure (mm Hg), estimated diameter (mm), cross-sectional area (mm2), distensibility (mm2/mm Hg), and zone compliance (mm3/mm Hg). RESULTS: In total, 180 readings were successfully accomplished. Most of the measured values were nearing lower average figures for the lower oesophageal sphincter, and upper average figures for the pylorus in healthy humans. The porcine pyloric sphincter is composed of the Torus pyloricus. It serves as a study "gatekeeper" between the stomach and D1 duodenum, thus explaining higher pyloric readings. There was a clear trend for increasing values of CSA (cross-sectional area), diameter, and balloon pressure with increased filling balloon volumes. However, the sphincter distensibility did not change with increasing filling volumes, either for the lower oesophageal sphincter or pylorus. CONCLUSION: Endoscopic functional luminal planimetry in experimental pigs is feasible, both for the lower oesophageal sphincter and the pylorus. This is an important starting point for future experimental endoscopic trials and pharmacology studies.

Charles University 1st Faculty of Medicine and Military University Hospital Prague Department of Medicine Prague Czech Republic

Charles University 1st Faculty of Medicine Institute of Physiology Prague Czech Republic

Institute for Clinical and Experimental Medicine Department of Hepatogastroenterology Prague Czech Republic

Military University Hospital Prague Institute of Gastrointestinal Oncology Prague Czech Republic

The Royal Marsden NHS Foundation Trust London United Kingdom

University Hospital Hradec Kralove Biomedical Research Centre Hradec Kralove Czech Republic

University of Defence Military Faculty of Medicine Animal Laboratory Hradec Kralove Czech Republic

University of Ostrava Faculty of Medicine Academic Department of Internal Medicine Ostrava Czech Republic

See more in PubMed

Arroyo Vázquez JA, Bergström M, Bligh S, McMahon BP, Park PO (2018). Exploring pyloric dynamics in stenting using a distensibility technique. Neurogastroenterol Motil 30(12): e13445. DOI: 10.1111/nmo.13445. PubMed DOI

Ata-Lawenko RM, Lee YY (2017). Emerging Roles of the Endolumenal Functional Lumen Imaging Probe in Gastrointestinal Motility Disorders. J Neurogastroenterol Motil 23(2): 164-170. DOI: 10.5056/jnm16171. PubMed DOI

Bredenoord AJ, Rancati F, Lin H, Schwartz N, Argov M (2022). Normative values for esophageal functional lumen imaging probe measurements: A meta-analysis. Neurogastroenterol Motil 34(11): e14419. DOI: 10.1111/nmo.14419. PubMed DOI

Bures J, Kvetina J, Radochova V, Knoblochova V, Rejchrt S, Valis M, et al. (2022). Effect of ketamine, an NMDA-receptor antagonist, on gastric myoelectric activity in experimental pigs. Mil Med Sci Lett 91(Suppl. 1): 15.

Bures J, Kvetina J, Radochova V, Tacheci I, Peterova E, Herman D, et al. (2020). The pharmacokinetic parameters and the effect of a single and repeated doses of memantine on gastric myoelectric activity in experimental pigs. PLoS One 15(1): e0227781. DOI: 10.1371/journal.pone.0227781. PubMed DOI

Bures J, Kvetina J, Tacheci I, Pavlik M, Kunes M, Rejchrt S, et al. (2015). The effect of different doses of atropine on gastric myoelectrical activity in fasting experimental pigs. J Appl Biomed 13: 273-277. DOI: 10.1016/j.jab.2015.04.004. DOI

Bures J, Radochova V, Kvetina J, Kohoutova D, Valis M, Rejchrt S, et al. (2023). Wireless Monitoring of Gastrointestinal Transit Time, Intra-luminal pH, Pressure and Temperature in Experimental Pigs: A Pilot Study. Acta Medica (Hradec Kralove) 66(1): 11-18. DOI: 10.14712/18059694.2023.9. PubMed DOI

Bures J, Tacheci I, Kvetina J, Radochova V, Kohoutova D, Valis M, et al. (2021a). Dextran Sodium Sulphate-Induced Gastrointestinal Injury Further Aggravates the Impact of Galantamine on the Gastric Myoelectric Activity in Experimental Pigs. Pharmaceuticals (Basel) 14(6): 590. DOI: 10.3390/ph14060590. PubMed DOI

Bures J, Tacheci I, Kvetina J, Radochova V, Prchal L, Kohoutova D, et al. (2021b). The Impact of Dextran Sodium Sulfate-Induced Gastrointestinal Injury on the Pharmacokinetic Parameters of Donepezil and Its Active Metabolite 6-O-desmethyldonepezil, and Gastric Myoelectric Activity in Experimental Pigs. Molecules 26(8): 2160. DOI: 10.3390/molecules26082160. PubMed DOI

Carlson DA, Kou W, Lin Z, Hinchcliff M, Thakrar A, Falmagne S, et al. (2019). Normal Values of Esophageal Distensibility and Distension-Induced Contractility Measured by Functional Luminal Imaging Probe Panometry. Clin Gastroenterol Hepatol 17(4): 674-681.e1. DOI: 10.1016/j.cgh.2018.07.042. PubMed DOI

Chen HM, Li BW, Li LY, Xia L, Chen XB, Shah R, et al. (2019). Functional lumen imaging probe in gastrointestinal motility diseases. J Dig Dis 20(11): 572-577. DOI: 10.1111/1751-2980.12818. PubMed DOI

Clarke JO, Ahuja NK, Fernandez-Becker NQ, Gregersen H, Kamal AN, Khan A, et al. (2020). The functional lumen imaging probe in gastrointestinal disorders: the past, present, and future. Ann N Y Acad Sci 1482(1): 16-25. DOI: 10.1111/nyas.14463. PubMed DOI

Council of Europe (1986). Explanatory Report to the European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes (European Treaty Series - No. 123). Strasbourg, 12 p.

Dantas RO, Alves LM, Cassiani R de A (2009). Gender differences in proximal esophageal contractions. Arq Gastroenterol 46(4): 284-287. DOI: 10.1590/s0004-28032009000400007. PubMed DOI

Dantas RO, Ferriolli E, Souza MA (1998). Gender effects on esophageal motility. Braz J Med Biol Res 31(4): 539-544. DOI: 10.1590/s0100-879x1998000400011. PubMed DOI

Desprez C, Roman S, Leroi AM, Gourcerol G (2020). The use of impedance planimetry (Endoscopic Functional Lumen Imaging Probe, EndoFLIP®) in the gastrointestinal tract: A systematic review. Neurogastroenterol Motil 32(9): e13980. DOI: 10.1111/nmo.13980. PubMed DOI

Dogan I, Mittal RK (2006). Esophageal motor disorders: recent advances. Curr Opin Gastroenterol 22(4): 417-422. DOI: 10.1097/01.mog.0000231818.64138.8a. PubMed DOI

Donnan EN, Pandolfino JE (2020). EndoFLIP in the Esophagus: Assessing Sphincter Function, Wall Stiffness, and Motility to Guide Treatment. Gastroenterol Clin North Am 49(3): 427-435. DOI: 10.1016/j.gtc.2020.04.002. PubMed DOI

Gonzalez C, Kwak JM, Davrieux F, Watanabe R, Marescaux J, Swanström LL (2019). Hybrid transgastric approach for the treatment of gastroesophageal junction pathologies. Dis Esophagus 32(2). DOI: 10.1093/dote/doy095. PubMed DOI

Gonzalez LM, Moeser AJ, Blikslager AT (2015). Porcine models of digestive disease: the future of large animal translational research. Transl Res 166(1): 12-27. DOI: 10.1016/j.trsl.2015.01.004. PubMed DOI

Hirano I, Pandolfino JE, Boeckxstaens GE (2017). Functional Lumen Imaging Probe for the Management of Esophageal Disorders: Expert Review from the Clinical Practice Updates Committee of the AGA Institute. Clin Gastroenterol Hepatol 15(3): 325-334. DOI: 10.1016/j.cgh.2016.10.022. PubMed DOI

Jagtap N, Kalapala R, Reddy DN (2020). Assessment of Pyloric Sphincter Physiology Using Functional Luminal Imaging Probe in Healthy Volunteers. J Neurogastroenterol Motil 26(3): 391-396. DOI: 10.5056/jnm19200. PubMed DOI

Kararli TT (1995). Comparison of the gastrointestinal anatomy, physiology, and biochemistry of humans and commonly usedlaboratory animals. Biopharm Drug Dispos 16(5): 351-380. DOI: 10.1002/bdd.2510160502. PubMed DOI

Lottrup C, Gregersen H, Liao D, Fynne L, Frøkjaer JB, Krogh K, et al. (2015). Functional lumen imaging of the gastrointestinal tract. J Gastroenterol 50(10): 1005-1016. DOI: 10.1007/s00535-015-1087-7. PubMed DOI

McMahon BP, Frøkjaer JB, Drewes AM, Gregersen H (2004). A new measurement of oesophago-gastric junction competence. Neurogastroenterol Motil 16(5): 543-546. DOI: 10.1111/j.1365-2982.2004.00540.x. PubMed DOI

McMahon BP, Frøkjaer JB, Liao D, Kunwald P, Drewes AM, Gregersen H (2005). A new technique for evaluating sphincter function in visceral organs: application of the functional lumen imaging probe (FLIP) for the evaluation of the oesophago-gastric junction. Physiol Meas 26(5): 823-836. DOI: 10.1088/0967-3334/26/5/019. PubMed DOI

Mittal RK, Liu J, Puckett JL, Bhalla V, Bhargava V, Tipnis N, Kassab G (2005). Sensory and motor function of the esophagus: lessons from ultrasound imaging. Gastroenterology 128(2): 487-497. DOI: 10.1053/j.gastro.2004.08.004. PubMed DOI

O'Dea J, Siersema PD (2013). Esophageal dilation with integrated balloon imaging: initial evaluation in a porcine model. Therap Adv Gastroenterol 6(2): 109-114. DOI: 10.1177/1756283X12467566. PubMed DOI

Pandolfino JE, Shi G, Curry J, Joehl RJ, Brasseur JG, Kahrilas PJ (2002). Esophagogastric junction distensibility: a factor contributing to sphincter incompetence. Am J Physiol Gastrointest Liver Physiol 282(6): G1052-1058. DOI: 10.1152/ajpgi.00279.2001. PubMed DOI

Pandolfino JE, Shi G, Zhang Q, Ghosh S, Brasseur JG, Kahrilas PJ (2005). Measuring EGJ opening patterns using high resolution intraluminal impedance. Neurogastroenterol Motil 17(2): 200-206. DOI: 10.1111/j.1365-2982.2004.00589.x. PubMed DOI

Perretta S, Dallemagne B, Allemann P, Marescaux J (2010). Multimedia manuscript. Heller myotomy and intraluminal fundoplication: a NOTES technique. Surg Endosc 24(11): 2903. DOI: 10.1007/s00464-010-1073-3. PubMed DOI

Perretta S, Dallemagne B, Donatelli G, Diemunsch P, Marescaux J (2011). Transoral endoscopic esophageal myotomy based on esophageal function testing in a survival porcine model. Gastrointest Endosc 73(1): 111-116. DOI: 10.1016/j.gie.2010.09.009. PubMed DOI

Popescu M, White E, Mutalib M (2023). EndoFLIP assessment of pyloric sphincter in children: a single-center experience. Transl Gastroenterol Hepatol 8: 17. DOI: 10.21037/tgh-22-58. PubMed DOI

Regan J, Walshe M, Rommel N, Tack J, McMahon BP (2013). New measures of upper esophageal sphincter distensibility and opening patterns during swallowing in healthy subjects using EndoFLIP®. Neurogastroenterol Motil 25(1): e25-34. DOI: 10.1111/nmo.12041. PubMed DOI

Rivera Bermudez MA, Swanson L, Townsend A, Hunter SE, Saunders JK, Wise KB, et al. (2015). Characterization of Swine Models of Benign Esophageal Stricture for the Evaluation of Esophageal Stents. Gastrointest Endoscopy 81(Suppl. 5): AB529-AB530. DOI: 10.1016/j.gie.2015.03.1802. DOI

Shaker R, Bardan E, Gu C, Massey BT, Sanders T, Kern MK, et al. (2004). Effect of lower esophageal sphincter tone and crural diaphragm contraction on distensibility of the gastroesophageal junction in humans. Am J Physiol Gastrointest Liver Physiol 287(4): G815-821. DOI: 10.1152/ajpgi.00120.2004. PubMed DOI

Soliman H, Gourcerol G (2023). Targeting the pylorus in gastroparesis: From physiology to endoscopic pyloromyotomy. Neurogastroenterol Motil 35(2): e14529. DOI: 10.1111/nmo.14529. PubMed DOI

Suenderhauf C, Parrott N (2013). A physiologically based pharmacokinetic model of the minipig: data compilation and model implementation. Pharm Res 30(1): 1-15. DOI: 10.1007/s11095-012-0911-5. PubMed DOI

Tachecí I, Radochová V, Květina J, Rejchrt S, Kopáčová M, Bureš J (2015). Oesophageal Manometry in Experimental Pigs: Methods and Initial Experience. Acta Medica (Hradec Kralove) 58(4): 131-134. DOI: 10.14712/18059694.2016.5. PubMed DOI

Tsianou CC, Kvetina J, Radochova V, Kohoutova D, Rejchrt S, Valis M, et al. (2023). The effect of single and repeated doses of rivastigmine on gastric myoelectric activity in experimental pigs. PLoS One 18(6): e0286386. DOI: 10.1371/journal.pone.0286386. PubMed DOI

Tveden-Nyborg P, Bergmann TK, Lykkesfeldt J (2018). Basic & Clinical Pharmacology & Toxicology Policy for Experimental and Clinical studies. Basic Clin Pharmacol Toxicol 123(3): 233-235. DOI: 10.1111/bcpt.13059. PubMed DOI

Ullal TV, Marks SL, Belafsky PC, Conklin JL, Pandolfino JE (2022). A Comparative Assessment of the Diagnosis of Swallowing Impairment and Gastroesophageal Reflux in Canines and Humans. Front Vet Sci 9: 889331. DOI: 10.3389/fvets.2022.889331. PubMed DOI

Vackova Z, Levenfus I, Pohl D (2023). Interventional functional diagnostics in gastrointestinal endoscopy: Combining diagnostic and therapeutic tools in the endoscopy suite with the functional lumen imaging probe. Curr Opin Pharmacol 73: 102414. DOI: 10.1016/j.coph.2023.102414. PubMed DOI

van Hees H (2022). Fibre in the diet of the suckling pig: Opportunities for the maturation of the gastrointestinal tract and post-weaning resilience. Thesis, Ghent University. [online] [cit. 2024-06-24]. Available from: https://www.researchgate.net/publication/359557436

Wu PI, Sloan JA, Kuribayashi S, Gregersen H (2020). Impedance in the evaluation of the esophagus. Ann N Y Acad Sci 1481(1): 139-153. DOI: 10.1111/nyas.14408. PubMed DOI

Yim B, Gregor L, Siwiec RM, Al-Haddad M, Nowak TV, Wo JM (2023). Pyloric Functional Lumen Imaging Probe Measurements Are Dependent on Balloon Position. J Neurogastroenterol Motil 29(2): 192-199. DOI: 10.5056/jnm22053. PubMed DOI

Zheng T, Vosoughi K, Busciglio I, Tebay L, Burton D, Camilleri M (2022). Fasting pyloric diameter and distensibility by functional endoluminal imaging probe in unsedated healthy volunteers. Neurogastroenterol Motil 34(10): e14386. DOI: 10.1111/nmo.14386. PubMed DOI

20 ml 30 ml 40 ml20 ml 30 ml 40 ml20 ml 30 ml 40 ml20 ml 30 ml 40 ml