Intra-arterial versus negative-staining of embryonal resection borders with indocyanine green (ICG) fluorescence for total mesorectal excision in colorectal cancer – an experimental feasibility study in a porcine model

Abstract

Background

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Laparoscopic lower rectal resections in accordance with the oncological principles are recommended as the gold standard for CRC surgical management. However, the learning curve for adopting these techniques is quite steep and the incomplete resections are predictive of local recurrence. This study was conducted in an attempt to find a way to help surgeons to overcome some of these difficulties and define the right resection margins.

Material and methods

As such, we carried out two laparoscopic lower rectal resections in porcine models. The first resection was performed following the ligation and selective infusion of Indocyanine Green (ICG) into the inferior mesenteric artery (IMA), and the second after the ligation of both inferior mesenteric artery and vein (IMV) and systemic intravenous infusion of ICG. Fluorescence was detected in real time by means of an infrared imaging system.

Results

Sharp resection margins were defined after intra-arterial infusion, and all the tissues in the IMA basin were colored in the first case. In the second model every organ and tissue was colored except the rectum, urinary bladder and ductus deferens.

Conclusions

Although systemic intra-venous application of ICG and negative-staining of the rectum including the mesorectum is much easier compared to laparoscopic inter-arterial perfusion through IMA, image results of selevtive IMA-perfusion appear in sharper discrimination of the several layers. Further investigation should focus on simplifying this technique.

Keywords:

• ICG
• CRC
• TME

Declaration of interest

The authors declare that they have no conflict of interest.

Additional information

Funding

Every procedure was performed in accordance with the recommendations and guidelines for the care of laboratory animals by the Error! Hyperlink reference not valid. and after an approval by the local Ethics Committee for experiments involving animals (FIM-18-105).