Morphofunctional State of the Small Intestine in the Acute Period of Spinal Injury: Early Microcirculation Disorders and Ways of their Correction (Experimental Study)

Introduction. One of the important systems that requires close attention in patients with traumatic spinal cord disease (TSCD) is the gastrointestinal tract. The development of spinal shock leads to a sharp drop in blood pressure, to disruption of splanchnic blood circulation and, as a consequence, to ischemic damage to the intestine, its paresis, disruption of nutrient absorption, and cachexia. Active intraintestinal therapy can improve the treatment results of such patients.
Objective. In the experiment, to determine changes in the intramural blood supply to the small intestinal wall in the acute period of traumatic damage to the spinal cord and the e ffect of increased intraintestinal pressure on it.
Materials and methods. The experimental study was performed on male rats weighing 215–315 g (n=20), with spinal cord injury modeled. The intramural vascular bed of the small intestine was monitored using optical coherence angiography (OCA): at the first stage of the experiment — before modeling the injury, after 3 hours and after 24 hours; at the second stage of the experiment, 24 hours after the injury and then with the injection of physiological solution (0.9% NaCl) into the intestinal lumen at different pressures.
Results. Spinal cord injury results in a decrease in the overall density of the vascular network within 3 hours after injury compared to the intact intestine and statistically significantly progresses by the end of 24 hours. The introduction of a physiological solution into the lumen of the small intestine 24 hours after spinal injury modeling, at a pressure of 7 cm, results in the reappearance of some of the small-diameter blood vessels that had previously disappeared.
Conclusion. According to the OCA data, intramural microcirculation of the small intestine in the acute period of spinal injury is characterized by a decrease in the overall density of the vascular network. Dosed injection of physiological solution into the lumen of the small intestine at 7 cm of H2O leads to an increase in the density of the vascular network, bringing the indicators closer to the original ones.

1. Sadeghi-Naini M, Yousefifard M, Ghodsi Z, Azarhomayoun A, Kermanian F, Golpayegani M, et al. In-hospital mortality rate in subaxial cervical spinal cord injury patients: a systematic review and meta-analysis. Acta Neurochir (Wien). 2023;198(2):69-74. https://doi.org/10.1007/s00701-023-05720-5.

2. Baleev MS, Ryabkov MG, Perlmutter OA, et al. Laboratory Signs of Enteric Failure - Predictors of Pressure Ulcers in Traumatic Spinal Cord Disease. Journal of experimental and clinical surgery. 2021;14(2):112-118. (In Russ.). https://doi.org/10.18499/2070-478X-2021-14-2-112-118.

3. Khalidov OKh. Combination of resonant electrical stimulation, serotonergic agents and enteral lavage in complex correction of intra-abdominal hypertension and intestinal paresis in severe acute pancreatitis // High-tech medicine. 2018;12(1):23-34. (In Russ.).

4. Evseev MA, Fomin VS, Nikitin VE. Pathogenetic aspects of the development of enteral insufficiency syndrome in the postoperative period // Annals of Surgery. 2018; 23(1):5-13. (In Russ.).

5. Abdulzhalilov MK. Efficiency of enteral antihypoxic and selective therapy of intestinal anastomosis in the treatment of acute small intestinal obstruction // Bulletin of the Dagestan State Medical Academy.2018;(4):5-20. (In Russ.).

6. Higa OH. Protective effects of ascorbic acid pretreatment in a rat model of intestinal ischemia-reperfusion injury: a histomorphometric study. Clinics. 2007;(3):315-320. https:// doi.org/10.1590/s1807-59322007000300017.

7. Sizlan A. Proanthocyanidin protects intestine and remote organs against mesenteric ischemia/reperfusion injury. World J. Surg. 2009;33(7):1384-1391. https://doi.org/10.1007/s00268-009-0011-9.

8. Tóth Š, Pekárová T, Varga J, Tóth Š, Tomečková V, Gál P, et al. Intravenous administration of tetramethylpyrazine reduces intestinal ischemia-reperfusion injury in rats. Am. J. Chin. Med. 2013; 41(4):817-829. https://doi.org/10.1142/S0192415X13500559.

9. Widgerow AD. Ischemia-reperfusion injury: influencing the microcirculatory and cellular environment. Ann. Plast. Surg. 2014;72(2):253-260. https://doi.org/10.1097/SAP.0b013e31825c089c.

10. Basarab DA. Microcirculatory effects of perfluorane on the model of acute intestinal ischemia. Regional circulation and microcirculation. 2013;2(2):67-75. (In Russ.).

11. Shur VYu. Serotonin: biological properties and prospects for clinical use. Fundamental research. 2014. 7(3):621-629. (In Russ.).

12. Magomedov MA. Pathogenetic substantiation and experience of using serotonin adipate in complex therapy of functional intestinal obstruction in surgical practice. Clinical analysis in general medicine. 2022;6:70-76. (In Russ.).

13. Ayididaer A. Post-treatment with yiqifumai injection and its main ingredients attenuates lipopolysaccharide-induced microvascular disturbance in mesentery and ileum. Microcirculation. 2021;28(4):e12680. https://doi.org/10.1111/micc.12680.

14. Kiseleva E, Ryabkov M, Baleev M, Bederina E, Shilyagin P, Moiseev A, et al. Prospects of intraoperative multimodal OCT application in patients with acute mesenteric ischemia. Diagnostics. Special Issue “Multimodal Optical Coherence Tomography in Diagnostics and Treatment Monitoring of Human Diseases”. 2021;11(4):705:1-23. https://doi.org/10.3390/diagnostics11040705.

15. Dowling LR, Strazzari MR, Keely S, Kaiko GE. Enteric nervous system and intestinal epithelial regulation of the gut-brain axis. J Allergy Clin Immunol. 2022;150(3):513-522. https://doi.org/10.1016/j.jaci.2022.07.015.

16. Fedoniuk LY, Lomakina YV, Bilyk YO. Assessment of laboratory animal functional status: modern methodological approaches for conducting biomedical research. Pol Merkur Lekarski. 2023;51(5):569-574. https://doi.org/10.36740/Merkur202305118.

17. Yu G, Zhou X. Gender difference in the pharmacokinetics and metabolism of VX-548 in rats. Biopharm Drug Dispos. 2024;45(2):107-114. https://doi.org/10.1002/bdd.2387.

18. Matveev LA, Zaitsev VY, Gelikonov GV, Matveyev AL, Moiseev AA, Ksenofontov SY, et al. Hybrid M-mode-like OCT imaging of three-dimensional microvasculature in vivo using reference-free processing of complex valued B-scans. Opt Lett. 2015;40(7):1472-1475. https://doi.org/10.1364/OL.40.001472.

19. Moiseev A, Ksenofontov S, Gorozhantseva M, Shakhova N, Sirotkina M, Kiseleva E, et al. Real time OCT-based angiography device with hand-held probe for everyday clinical use. J Biophotonics 2018;11:e201700292. https://doi.org/10.1002/jbio.201700292.

20. Shulpekova YuO. Mechano and chemoreceptors of the large intestine and the possibility of medicinal effects on them. Russian medical journal. 2013;21(13):714-718. (In Russ.).