Imaging and observation of microcirculation in bowel mucosa using sidestream dark field imaging

Sidestream dark field (SDF) imaging is a tool for assessing microcirculation, commonly used for early diagnosis and monitoring of sepsis. In this study, we used SDF imaging to observe and assess the microcirculation of the intestinal mucosa during bowel surgery. We also compared different performance between normal mucosa and diseased mucosa using SDF imaging. SDF imaging was conducted in 13 patients to evaluate microcirculation parameters. All patients were assessed at distances of 0, 1, 2, 3 and 4 centimeters (cm) from the edge of the mesentery, respectively. Microcirculatory parameters such as microvascular flow index (MFI), proportion of perfused vessels (PPV), vascular density (VD), total vessel density (TVD), perfused vessel density (PVD) and heterogeneity index (HI) were measured in these patients. Compared to normal intestinal mucosa, the diseased intestinal mucosa exhibited higher values for VD (p = 0.044), TVD (p = 0.006) and PVD (p = 0.007). No significant differences in PPV, MFI and HI were observed between the two groups. The microcirculation parameters (MFI, PPV and PVD) of the intestine at the distal distance of 3 cm were significantly lower than those at a distance of 2 cm (MFI 1.5 (0.75) vs. 3 (0.5), PPV 57.6 (9.1) vs. 97.1 (8.6)% and PVD 11.395 (3.082) vs. 20.726 (4.115) mm/mm²). In conclusion, SDF imaging is an advanced technique that provide real-time visualization of intestinal mucosal microcirculation. It has the potential to assess the blood perfusion of the intestine during surgery.