Examination of Rectal Blood Supply During Rectal Cancer Surgery Using Laser Speckle Contrast Imaging

Feasibility is considered demonstrated if time spent on PerfusiX-Imaging measurements is ≤ 5% of total operating time and no more than two measurements are required to obtain a sufficient assessment of intestinal microcirculation.

Unit:

Percentage of participants with succesful assessment

Surgeons will assess the acceptability and performance of PerfusiX-Imaging using a predefined Likert-scale questionnaire. Feasibility will be considered demonstrated if >80% of surgeons report a positive evaluation of PerfusiX-Imaging. A positive evaluation is defined as a Likert score of ≥ 4 on at least three of the four predefined evaluation questions.

Unit:

Percentage of surgeons with a positive evaluation

The distance between the marked oral transection line with and without the use of PerfusiX-Imaging given by the surgeon and an independent expert. Feasibility will be considered demonstrated if the transection line differs by ≥ 10 mm.

Unit: milimetres (mm)

Surgeons will assess the acceptability and performance of PerfusiX-Imaging and ICG-FI using a predefined Likert-scale questionnaire. A positive evaluation is defined as a Likert score of ≥ 4 on at least three of the four predefined evaluation questions. The proportion of surgeons providing a positive evaluation of PerfusiX-Imaging will be compared with the proportion providing a positive evaluation on ICG-FI.

Unit of measure:

Proportion of surgeons

Intestinal microcirculation will be quantified using laser speckle contrast imaging (LSCI). Absolute microcirculation will be expressed as the mean laser speckle perfusion unit (LSPU) value obtained from a predefined region of interest (ROI) close to the intestinal anastomotic line.

Unit of measure:

Laser speckle perfusion units, LSPU

Relative intestinal microcirculation will be calculated by normalizing the mean LSPU value from a region of interest to the mean LSPU value obtained from a reference region on the intestines:

Unit of measure:

Percentage (%): measurement/control*100

Length of initial hospital stay after surgery will be calculated as the number of hours from the end of surgery until initial discharge from hospital. The association between length of initial hospital stay after surgery and quantitative measurements of intestinal microcirculation will be explored.

Unit of measure:

Hours

Postoperative complications occuring within 30 days after surgery will be graded according to the Clavien-Dindo classification (Grade I-V). The asociation between quatitative measurements of intestinal microcirculation and the severity of postoperative complications will be explored.

Units of measure:

Clavien-Dindo

The occurence of surgical complications within 30 days after surgery will be recorded. Surgical complications include bleeding, fascial dehiscence, postoperative ileus, surgical site infection, intraabdominal abscess, stoma related complications. The association between surgical complications within 30 days after surgery and quantitative measurements of intestinal microcirculation will be explored.

Units of measure:

Participants with one or more surgical complications

The occurence of medical complications within 30 days after surgery will be recorded. Medical complicatinos include stroke, myocardial infarction, heart failure, pneumonia, aspiration, respiratory failure, deep vein thrombosis, acute arterial insufficiency and sepsis. The association between medical complications within 30 days after surgery and quantitative measurements of intestinal microcirculation will be explored

Units of measure:

Participants with one or more medical complications

Occurrence of anastomotic leakage within 30 days after surgery will be recorded as a binary outcome (yes/no). The association between anastomotic leakage and quantitative measurements of intestinal microcirculation will be explored.

Units of measure:

Participants with anastomotic leakage