In this study, gastrointestinal anastomoses are examined with a hyperspectral camera and after this the investigators use the Standard Routine ICG-Imaging. At the end, both methods will be compared..

All gastrointestinal anastomoses were examined in all patients with written informed consent.

As Standard in our clinical Routine the tissue perfusion is measured with fluorescence Imaging and Indocyaningreen (ICG). In this study the investigators use the Hyperspectral-Camera (HSI-Camera) as new method. The measurements were performed like described before, using the TIVITA Tissue system (Diaspective Vision GmbH, Am Salzhaff, Germany). This HSI-camera provides hyperspectral images with a high spectral resolution (5 nm) in the visible and near infrared range (500-1000 nm). A RGB image and 4 false color images that represent physiologic parameters are intraoperatively provided by an analysis software. This work is focused on tissue oxygenation (StO2), which represents the relative blood oxygenation in the microcirculation of superficial tissue layers (approximately 1 mm) and the near-infrared (NIR) Perfusion Index, representing tissue layers in 4-6 mm penetration depth.

As Standard method ICG-Fluorescence Imaging is used. After the procedure the Perfusion data of both Systems is compared.

Inclusion Criteria:

• all gastrointestinal anastomoses

Exclusion Criteria:

• inability to consent
• allergy against indocyaningreen dye

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