## 3 Results
### Quantitative Parameters
SDF Sidestream Darkfield Imaging: TVD total vessel density in mm/mm\({}^{2}\), PVD perfused vessel density in mm/mm\({}^{2}\), MFI microvascular flow index, DBS de Backer score, PPV proportion (%) of perfused vessels. LSCI Laser Speckle Contrast Imaging: Flux in LSPU (laser speckle perfusion units), \(\Delta\)%Flux percentage difference in Flux relative to Location 1 (right vertical axis). * Not calculated, _p_-value calculated on absolute data (see Flux). FA Fluorescence Angiography: Influx time point in sec, F\({}_{\text{max}}\) in arbitrary units, T\({}_{\text{max}}\) in sec, T\({}_{1/2}\) in sec, mean slope in arbitrary units per sec. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & & **Location 4** & **Location 4** & \\  & & **No Anastomotic** & **Anastomotic** & **_p_-Value** \\ \hline
**OCT** & Speckle (\%) & 21 (14–31) & 17 (17) & 0.600 \\ \hline  & TVD (mm/mm\({}^{2}\)) & 8.7 (5.1–15.9) & 9.8 (9.5–17.4) & 0.088 \\ \cline{2-5}
**SDF** & PVD (mm/mm\({}^{2}\)) & 0.5 (0.0–7.0) & 2.0 (0.9–5.4) & 0.155 \\ \cline{2-5}  & MFI & 1.1 (0.3–2.0) & 1.3 (1–1.5) & 0.646 \\ \cline{2-5}  & DBS & 5.4 (3.0–10.3) & 7.2 (6.9–11.00) & 0.056 \\ \cline{2-5}  & PPV (\%) & 5.7 (0.0–86.4) & 21.3 (9.3–31.1) & 0.155 \\ \cline{2-5}  & Velocity (\(\mu\)m/s) & 15.2 (4.3–186.0) & 23.8 (14.8–60.3) & 0.560 \\ \hline
**LSCI** & Flux (LSPU) & 128.7 (41.1–480.5) & 167.1 (114.1–335.2) & 0.422 \\ \cline{2-5}  & \(\Delta\)%Flux (\%) & 54 (–31–87) & 82 (52–87) & 0.072 \\ \hline  & Influx time point (s) & 39.5 (21–73) & 44.0 (42–46) & 0.673 \\ \cline{2-5}
**FA** & F\({}_{\text{max}}\) (AU) & 39.8 (1.8–163.2) & 12.3 (10.9–13.7) & 0.131 \\ \cline{2-5}  & T\({}_{\text{max}}\) (s) & 38.8 (34.2–44.6) & 39.8 (31.1–48.58) & 0.888 \\ \cline{2-5}  & T\({}_{1/2}\) (s) & 13.0 (6.3–21.3) & 29.3 (27.8–30.8) & _0.025_ \\ \cline{2-5}  & Mean slope (AU/s) & 1.3 (0.1–11.0) & 0.2 (0.1–0.2) & _0.041_ \\ \hline \hline \end{tabular} Data are shown as median and total range. OCT Optical Coherence Tomography, SDF Sidestream Darkfield Imaging, TVD total vessel density in mm/mm\({}^{2}\), PVD perfused vessel density in mm/mm\({}^{2}\), MFI microvascular flow index, DBS de Backer score, PPV proportion (%) of perfused vessels. LSCI Laser Speckle Contrast Imaging, Flux in LSPU (laser speckle perfusion units), \(\Delta\)%Flux percentage difference in Flux relative to Location 1 (right vertical axis). * Not calculated, _p_-value calculated on absolute data (see Flux). FA Fluorescence Angiography: Influx time point in sec, F\({}_{\text{max}}\) in arbitrary units, T\({}_{\text{max}}\) in sec, T\({}_{1/2}\) in sec, mean slope in arbitrary units per sec.  
\end{table} 
Table 3: Comparison of the perfusion-related parameters at location 4 between patients with and without anastomotic leakage. At Loc1, the heart rate was correlated with the OCT parameter speckle % (\(\rho=0.669\), \(p=0.017\)). Systolic blood pressure was inversely correlated with LSCI parameter Flux (\(\rho=-0.451\), \(p=0.046\)), and stroke volume with SDF parameter MFI (\(\rho=-0.528\), \(p=0.017\)). No other significant correlations were observed for the quantitative and hemodynamic parameters.