Background

Impaired perfusion may cause tissue ischemia in revisional surgery. We determined real-time gastric perfusion under progressive aortic inflow/portal venous outflow occlusions in a gastric tube reliant on a single arterial supply using Laser Speckle Contrast Imaging (LSCI).

Methods

ActivSightTM is an FDA-cleared laparoscopic device that displays tissue perfusion as a color heatmap. A novel prototype quantification feature can also display tissue perfusion in relative perfusion units (RPU). A porcine gastric tube entirely dependent on the right gastroepiploic artery was created (Figure 1A) and tissue perfusion was measured for 30s using LSCI under conditions of progressive aortic inflow/portal venous outflow clamping (Figure 1B/1C).

Results

Average gastric perfusion decreased by 62+-25%/59+-12% from baseline with complete aortic/venous occlusion respectively. Perfusion exhibited a strong linear relationship as a function of distance from vascular source in both partial aortic/venous occlusion (Pearson's coefficient 0.93/0.94; 68+- 3%/73+- 4% lower RPU at gastric tip compared to base respectively) (Figure 2A/2B). At any given distance from vascular source in the meso-axial plane, inner curvature/middle of stomach demonstrated higher perfusion compared to outer curvature with progressive arterial occlusion (p<0.0001) (Figure 2A) and venous occlusion (p<0.005) (Figure 2B).

Conclusions

Regional perfusion in gastric tube declines linearly with increased distance from vascular source with both aortic/venous occlusions. Venous outflow and arterial inflow have significant impact on regional gastric perfusion, and inner curvature/middle of stomach region has relatively better perfusion than outer curvature. This prototype LSCI quantification tool may provide real time perfusion assessment in revisional gastric surgery.