Repairing the impaired gut vascular barrier as a novel therapeutic target for prolonged postoperative ileus: A scoping review

Figure 1 Pathological factors of prolonged postoperative ileus and the inflammatory response mediated by intestinal microvascular endothelial cells. A: Laparoscopic photo of the small intestine before surgical manipulation in the patient with colon cancer; B: Laparoscopic photo of the small intestine after surgical manipulation in the patient with colon cancer; C: Inflammatory response mediated by inflammatory response mediated by intestinal microvascular endothelial cells in prolonged postoperative ileus. Created in BioRender (Supplementary material).

Figure 2 Anatomy of the gut vascular barrier. The gut vascular barrier is present underneath the intestinal epithelium. It is primarily composed of a monolayer of intestinal microvascular endothelial cells (IMVECs) and is supported by enteric glial cells and pericytes. IMVECs are connected through tight junction and adherens junction. Plasmalemma vesicle-associated protein-1 is a distinctive protein of IMVECs. Created in BioRender (Supplementary material).

Figure 3 The physiological functions of the gut vascular barrier. A: Physiological barrier function of the gut vascular barrier (GVB); B: Anti-adhesion function of the GVB; C: Absorptive function of the GVB; D: Immunological function of the GVB. IL: Interleukin; NO: Nitric oxide; VLDL: Very low-density lipoprotein; TLR: Toll like receptors; NF-κB: Nuclear factor kappa-B; MAPK: Mitogen-activated protein kinases. Created in BioRender (Supplementary material).

Figure 4 Impairment of the gut vascular barrier as a critical factor in sustaining intestinal inflammation during prolonged postoperative ileus. A: Intestinal microvascular endothelial cell dysfunction; B: Increased permeability of the gut vascular barrier; C: Pathological angiogenesis; D: Hemodynamic changes. NO: Nitric oxide; iNOS: Inducible nitric oxide synthase; INF-γ: Interferon-γ; VE-cadherin: Vascular endothelial-cadherin; VEGF: Vascular endothelial growth factor; vWF: Von Willebrand factor. Created in BioRender (Supplementary material).

Figure 5 Improving the function of intestinal microvascular endothelial cells and repairing the damaged gut vascular barrier as potential therapeutic targets for prolonged postoperative ileus. IL: Interleukin; eNOS: Endothelial nitric oxide synthase; MAPK: Mitogen-activated protein kinases; NF-kB: Nuclear factor kappa-B; AJ: Adherens junction; TJ: Tight junction; PPOI: Prolonged postoperative ileus; IMVEC: Intestinal microvascular endothelial cell. Created in BioRender (Supplementary material).