Short summary

Cancer in the oesophagus is preferably treated with surgery. A serious complication to surgery is anastomotic leakage, which is responsible for 35% of postoperative deaths. The most important factor to ensure anastomotic healing is sufficient blood-supply.

We will evaluate whether we can use a fluorescent dye as a surrogate of sufficient blood supply AND whether we can quantify the blood perfusion using a newly developed software program.

Rationale

Cancer in the, oesophagus or gastro-oesophageal junction is a diagnosis with a poor five-year survival.

Surgical resection is the treatment of choice, but only approximately 30% of the patients are planned for curative surgery, which has significant morbidity and even mortality. One of the most feared complications is anastomotic leak (AL). AL is responsible for up to 35% of postoperative deaths, associated with increased risk of recurrence of cancer, decreases long-term survival and reduces the functional result and therefore reduces Quality of Life (QoL).

AL is defined as a full thickness defect and is graded; 

Type 1: Treated medically or with dietary modifications

Type 2: Requiring interventional treatment, but not surgery

Type 3: Requiring sugery.

Early diagnosis and intervention are critical in all cases in order to improve outcome. Non-operative strategies including covered stents, gastric tubes, additional chest tubes, broad-spectrum antibiotics and oral decontamination (Type 1 and 2). More seldom surgery is required. 

Many factors influence the anastomotic healing, but one of the most important factors, is to ensure sufficient blood-supply/oxygen tension. Therefore, the surgeon evaluates the gastric conduit (anastomosed to esophagus) by a subjective assessment of the perfusion (evaluation of colour, artery pulsation and arterial bleeding) to select the anastomotic zone. Studies in colorectal surgery have demonstrated that surgeon's intraoperative evaluation of perfusion and predicting the risk of AL has an extremely low sensitivity and specificity. Other factors that may influence anastomotic healing, include technical errors, tension on the anastomosis, patient comorbidity, pre-operative stent etc. Clearly, the optimal way to prevent morbidity and mortality related to AL is to prevent it happens. 

In animal experimental studies it has been evaluated whether ICG fluorescent imaging (ICG-FI), can be used as a surrogate of bowel blood perfusion. Both biochemical and histo-pathological data suggest that the method is feasible.

The fluorescent dye ICG is administered intravenously and binds directly to plasma proteins, not altering the protein form and stays intravascular. It is eliminated in the liver, excreted in the bile within 3-4 minutes after administered. 

In oesophageal surgery the use of ICG-FI has shown to be a feasible method in small cohort studies. A good perfusion evaluated by ICG-FI might correlate with a reduced risk of AL, and using  ICG-FI to define the optimal zone for the anastomosis on the conduit, a significant decrease in anastomotic leakage from 18% to 3% was demonstrated.

There is no consensus in how to evaluate ICG-FI. 

A Danish research team in Rigshospitalet, Copenhagen, has developed and validated a method of quantifying fluorescence imaging (qICG) to asses gastrointestinal perfusion. 

There has not yet been identified any cut-off values for sufficient perfusion.

Aim:

Primary objective:     Is it feasible to perform ICG-FI in MIO in supine and prone position? 

Secondary objective:    To evaluate whether qICG can be used in a clinical setting.

Tertiary objective:     Is the qICG different when performed in the abdomen and thoracic cavities, respectively?

Fourth objective:     Is there an inter-observer agreement/variance evaluated postoperative?

Description of the cohort

Adult patients undergoing Minimal Invasive Oesophagectomy (MIO) for cancer.

Data and biological material

Patient characteristics: Sex, age, BMI, ASA-score and Performance Status, alcohol consumption, smoking status. TNM stage, neo-adjuvant radio-chemotherapy, complications to surgery.

Visual evaluation and quantification of blood perfusion will be registered. 

Collaborating researchers and departments

Surgical Department C, Rigshospitalet, Copenhagen

• PhD Student, Nikolaj Nerup, MD