Comparison of Rates of Anastomotic Leak in Patients Undergoing Colo-rectal Surgery When Bowel Perfusion and Resection Margin is Deterimined by Intra-operative Infra-red Thermography or by Conventional Method
Condition: Colo-rectal Surgery; Anastomotic Leak Large Intestine; Anastomotic Leak Rectum
MeSH terms: Anastomotic Leak
Study type: Interventional

Summary: 
      Pilot RCT with 20 patients in both test and control group. In the control group resection &
      anastomosis was done using the conventional method. In the test group after devascularisation
      the resection line was marked on the bowel wall and IRT done using a forward looking infra-
      red camera with a rainbow display. Resection line was determined by a sharp change in colour
      on the display screen (corresponding to > 30C change in surface temperature) over the
      visualised bowel wall. Margins were revised if difference between surgeon and IRT determined
      resection lines were more than 1cm apart. Anastomosis was done as per surgeon's preference.AL
      was the primary outcome measure. Hospital stay, operative time, blood loss, post-operative
      complications as per Clavien-Dindo classification were the secondary outcome measures.
    

Detailed description: 
      A pilot randomised control study was done on adult patients undergoing elective open and
      lap-assisted colo-rectal surgery with ileo-colic, colo-colic, colo-rectal and colo-anal
      anastomoses. Patients who did not consent, who were operated in emergency, pouch surgeries
      and in whom resection and anastomosis was not performed were excluded.

      43 patients operated between August' 2021 to November' 2022 were allocated to test and
      control group by simple randomisation without blinding. In the test group after mesenteric
      devascularisation, the site of resection was marked by the operating surgeon. After that IRT
      was performed using Infra-red thermal imaging FLIR C2 portable camera in the video mode and
      the images seen in rainbow colour display mode. The bowel segments of interest were examined
      from a distance range of 6 to 12 inches at the standard operation theatre temperature and
      humidity. Colour mapping and corresponding temperature changes were used to demarcate
      vascularized and non-vascularized segments of bowel. IRT-guided resection line was assigned
      to the place where the greatest temperature "jump" was observed (corresponding to a change of
      >3oC and a sharp change of colour on the screen). The IRT determined resection line was
      compared with the position of the resection line determined by the surgeon using conventional
      method. A difference of greater than 1 cm between the IRT and surgeon determined resection
      line was classified as non-matching and the margin was revised till the difference was less
      than 1 cm. The process was repeated at proximal and distal resection margins. In the control
      group the resection line was determined by conventional visual and palpatory method. In both
      the groups after resection of bowel, anastomosis was done as per surgeon preference.
      Diverting loop ileostomy was done on surgeon's discretion. Occurrence of an anastomotic leak
      (AL) up-to 8weeks post-operatively was recorded as the primary outcome. AL was defined as
      at-least one of the following (i) Anastomotic defect noted on physical examination. (ii)
      Anastomotic defect confirmed in the operating room. (iii) Anastomotic defect seen on
      proctoscopy. (iv) Radiologic evidence of a leak consisting of either a defect in the
      anastomosis and an adjacent fluid collection or stranding or extravasation of rectal contrast
      into the extraluminal space. (v) Clinical evidence of leak such as feculent output from
      abdominal/pelvic drain. Operative time, blood loss, length of hospital-stay, 30-day mortality
      and post-operative complications as per the Clavien-Dindo scale were the secondary outcome
      measured.
    

Intervention name(s): Intra-operative Infra-red thermography
Intervention type(s): Other
Intervention description(s): . In the test group after devascularisation of the bowel segment surgeon marked the resection line using their conventional method, then IRT was used to determine the resection line using infra- red camera in rainbow display mode. Resection line was determined by abrupt colour change (corresponds to decrease in temperature >3 degree Celsius) over the visualised bowel wall. Margins were revised if difference between surgeon and IRT determined resection lines were more than 1cm apart.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: . In the test group after devascularisation of the bowel segment surgeon marked the resection line using their conventional method, then IRT was used to determine the resection line using infra- red camera in rainbow display mode. Resection line was determined by abrupt colour change (corresponds to decrease in temperature >3 degree Celsius) over the visualised bowel wall. Margins were revised if difference between surgeon and IRT determined resection lines were more than 1cm apart.
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Infra-red thermography; Anastomotic leak; Colo-rectal Surgery