Mesenteric traction syndrome (MTS) is defined as hypotension, tachycardia and facial flushing in the first hour of surgery, caused by mesenteric traction/abdominal exploration. MTS occurs frequently during abdominal surgery, with incidence around 80 % during open surgery, and lower during minimally invasive surgery. MTS can be divided into different severities using the degree of facial flushing, with the most severe level of MTS being associated with increased postoperative morbidity.

Today MTS is diagnosed and graded subjectively by the surgical team, with marked difficulty and limitations. Therefore the investigators developed a cut-off value using the Laser Speckle Contrast Imaging (LSCI), which the investigators wish to confirm in a new cohort, while also examining whether LSCI is interchangeable with digital thermography, which is simpler and cheaper to perfom.

The investigators will measure facial perfusion during the first hour of surgery and take blood samples at predefined timepoints to use for biochemical verification of the different severities of MTS.

Three cohorts we planned to include 45 open esophagectomies or gastrectomies 50 whipple surgery 20 robot assisted esophagectomies or gastrectomies These patients will be use in multiple articles examining different aspects of MTS

One study examining LSCI and thermography for the identification and grading of MTS will use 60 patients undergoing open esophagectomy or gastrectomy or whipple surgery, in this study patients will not be excluded if they are found to be disseminated.

However we ended up including 37 open esophagectomies - due to few patients undergoing open esophagectomy, this were included over a time period of almost 2,5 years 50 whipple 11 Robotic esophagectomies - due to LSCI being impossible to use on robotic esophagectomies and thermography being diffciult to fit on these patients and as such not being feasible

Inclusion Criteria:

• Undergoing curative surgery for esopageal, gastric, doudenal or pancreatic cancer

Exclusion Criteria:

• Known flushing disease
• Patients recieving NSAID and corticosteroid presurgery, Whipple is allowed to recieve single dose of 125 mg Methylprednisone as part of the standard of care at our facility.
• Palliative surgery
• Surgery not completed due to disseminated disease - patients will still be used in examination of LSCI and Thermography analysis even if desiminated

3 cohorts

• open esophagectomies
• robotic assisted esophagectomies
• whipples procedure