Short summary

A serious complication to colorectal surgery is anastomotic leakage (AL). AL increases post-operative mortality, decreases long-term survival, reduces the functional result and reduces quality of life. Studies suggest that by performing an indocyanine-green enhanced fluorescent angiography (ICGeFA) blood perfusion in the bowel can be visualised. It is suggested that using this procedure will reduce the relative risk of AL approximately 54-67%.

With this project we wish to evaluate the feasibility of the procedure and, if proven feasible, to plan further studies evaluating the procedure. 

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Rationale

Colorectal cancer is one of the most common cancer diagnoses in Denmark. In 2014 5186 patients with colorectal cancer were registered. 1674 patients had cancer in the rectum and 1316 in the sigmoid colon. 668 patients underwent surgery with low anterior resection (LAR) and primary anastomosis and 850 patients had a sigmoid resection with primary anastomosis.

A serious complication is anastomotic leakage (AL). In 2014 a total of 67 (10%) patients were registered with AL.

In general, AL increases the post-operative mortality, decreases long-term survival and reduces the functional result and thereby reduces quality of life.

Due to the possible severity of AL all measures possible should be taken to ensure an early diagnosis and timely treatment, as this has been shown to reduce morbidity and mortality. The symptoms of AL are uncharacteristic; the diagnosis cannot only rely on the development of clinical symptoms. However, specific clinical scoring symptoms, measuring C-reactive protein (CRP) and radiologic examinations are proven useful.

Treatment of AL varies with the degree of leakage, from conservative treatment with rectal lavage, endo-VAC therapy, drainage of abscesses, re-laparoscopy or laparotomy with a diverting stoma and finally to break down the anastomosis and creating a temporary or permanent colostomy, all procedures with or without antibiotic treatment.

It is essential that surgeons continuously strive to improve the operative technique with regard to anastomosis construction. Many factors influence the anastomotic healing: instrumentation error, tension on the anastomosis, bacterial contamination, etc. An important factor to ensure the most optimal conditions in anastomotic healing is to ensure sufficient blood-supply/oxygen tension.

The surgeon evaluates so-called surrogates of bowel perfusion (evaluation of colour, mesenteric pulsation and arterial bleeding) prior to forming the anastomosis, but studies have demonstrated that for the surgeon's intraoperative judgement in prediction of anastomotic leakage, AL has an extremely low sensitivity and specificity.

Studies suggest that by performing an indocyanine-green enhanced fluorescent angiography (ICGeFA) the blood perfusion in the bowel can be visualised. It is suggested that by evaluating perfusion of bowel ends and, if needed, doing a re-resection, the risk of anastomotic leakage can be diminished. It is suggested that evaluating the anastomosis with ICG-FA and revising the anastomosis if necessary, the relative risk reduction of AL is approximately 54-67%. Several studies in robotic and laparoscopic colorectal surgery confirms feasibility of using ICGeFA, also showing promising results in evaluating the bowel perfusion. Most studies and a newly published systematic review conclude that there is great need for larger controlled studies or randomised trails.

The primary objective with this study is to evaluate the feasibility of using ICGeFA in colorectal surgery and to evaluate if the surgeon's interpretation is dose- and time dependent. The secondary objective is to establish a nationwide research team, joining all the Robotic Surgery Centres in Denmark for future research.

Finally we wish to identify the optimal design for a further study, evaluating whether ICG is a helpful tool in diminishing the risk of anastomotic leakage.

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Description of the cohort

Patient population: Patients, older than 18, undergoing robotic surgery for rectal cancer and cancers located low in the sigmoid bowel, <25 cm from the anal verge.

Exclusion: Allergy of iodide. Pregnancy. Lactation.   

Data and biological material

A 5-minute video clip during surgery, when bowel-perfusion is examined using ICG, will be saved for evaluation.

Patient characteristics: height, weight, alcohol- and tobacco consumption and comorbidity will be obtained from the electronic patient record. These informations will be used to evaluate the patients overall risk of complications to surgery.

Surgeons will be asked to describe the surgery, especially concerning time consumed, instruments used and blood loss.

Collaborating researchers and departments

Surgical Department A, Odense University Hospital

Surgical Department, Køge/Roskilde Hospital

Surgical Department, Vejle Hospital

Surgical Department, Aarhus University Hospital

Surgical Department, Herlev Hospital