Intestinal Mucosal and Serosal Microcirculation at the Planned Anastomosis during Abdominal Surgery

Abstract

Introduction: Intestinal blood flow is often named as a key factor in the pathophysiology of anastomotic leakage. The distribution between mucosal and serosal microperfusion during surgery remains to be elucidated. Objective: The aim of this study was to assess if the mucosal microcirculation of the intestine is more vulnerable to a surgical hit than the serosal microcirculation during surgery. Methods: In an observational cohort study (n = 9 patients), the microcirculation of the bowel serosa and mucosa was visualized with incident dark-field imaging during surgery. At the planned anastomosis, the following microcirculatory parameters were determined: microvascular flow index (MFI), percentage of perfused vessels (PPV), perfused vessel density (PVD), and total vessel density (TVD). Data are presented as median (interquartile range [IQR]). Results: Perfusion parameters and vessel density were significantly higher for the mucosa than the serosal microcirculation at the planned site for anastomosis or stoma. Mucosal MFI was 3.00 (IQR 3.00–3.00) compared to a serosal MFI of 2.75 (IQR 2.21–2.94), p = 0.03. The PPV was 99% (IQR 98–100) versus 92% (IQR 66–94), p = 0.01. The TVD was 16.77 mm/mm2 (IQR 13.04–18.01) versus 10.42 mm/mm2 (IQR 9.36–11.81), p = 0.01, and the PVD was 15.44 mm/mm2 (IQR 13.04–17.78) versus 9.02 mm/mm2 (IQR 6.43–9.43), p = 0.01. Conclusions: The mucosal microcirculation was preserved, while lower perfusion of the serosa was found at the planned anastomosis or stoma during surgery. Further research is needed to link our observations to the clinically relevant endpoint of anastomotic leakage.

Real-time visualization of renal microperfusion using laser speckle contrast imaging

“…SDF imaging can track the movement of individual RBCs enabling quantitative blood flow measurements and the detection of subtle microvascular changes. 17 – 19 SDF imaging is a contact method with a relatively small FOV of . The device has a total magnification of .…”

The effect of vasoconstriction on intestinal perfusion is determined by preload dependency: A prospective observational study

“…Moreover, it is assumed that the laser Doppler flow is measured in the serosa, for example, from the "serosa side," although the depth of the laser Doppler flow is not well described. Measures of perfusion in mucosa and serosa have been found to correlate, 32 33 suggesting that perfusion changes in serosal and mucosal may be divergent, but indicating the serosa side as giving the first indications of significant hypoperfusion. 26 In perspective, the assumption that intraoperative preload dependency, especially as induced by positional changes or sympatholysis induced by anesthesia and epidural analgesia, is primarily caused by insufficient circulating volume, is not necessarily true.…”

“…Moreover, it is assumed that the laser Doppler flow is measured in the serosa, for example, from the “serosa side,” although the depth of the laser Doppler flow is not well described. Measures of perfusion in mucosa and serosa have been found to correlate, 32 while lower perfusion of the serosa has been demonstrated at planned anastomosis sites during surgery, 33 suggesting that perfusion changes in serosal and mucosal may be divergent, but indicating the serosa side as giving the first indications of significant hypoperfusion 26 …”

Real-time visualization of renal microperfusion using laser speckle contrast imaging

“…SDF imaging can track the movement of individual RBCs enabling quantitative blood flow measurements and the detection of subtle microvascular changes. [17][18][19] SDF imaging is a contact method with a relatively small FOV of ∼1 mm 2 . The device has a total magnification of 750×.…”