# Evaluation of Blood Flow in a Reconstructed Gastric Conduit by Thermography in Esophageal Cancer Surgery

## TL;DR

This paper evaluates thermography as a potential tool for assessing blood flow in gastric conduits during esophageal cancer surgery, comparing it to ICG fluorescence.

## Contribution

The study demonstrates the potential of thermography as a non-invasive, drug-free alternative to ICG for evaluating blood flow in gastric conduits.

## Key findings

- Thermography images were consistent with ICG fluorescence in identifying blood flow boundaries in two case studies.
- Thermography allows for reevaluation at short intervals, which is not feasible with ICG.
- Thermography shows promise as an auxiliary diagnostic tool in clinical practice.

## Abstract

A complication of gastrointestinal anastomosis is anastomotic leakage; the incidence of anastomotic leakage following esophageal cancer surgery remains high. Several factors contribute to anastomotic leakage; however, blood flow to the reconstructed organ is the most significant factor. Currently, indocyanine green (ICG) fluorescence is widely used for evaluating blood flow; however, several issues have been observed, including allergic reactions to the drug. We investigated the usefulness of thermography (TG) for gastrointestinal blood flow evaluation.

Case 1 was a 76-year-old male who underwent thoracoscopic subtotal esophagectomy and gastric conduit reconstruction for esophageal cancer. ICG fluorescence was performed to evaluate gastrointestinal blood flow, and ICG fluorescence and TG were simultaneously performed. The early and final luminescent areas following ICG injection were consistent with the TG images. Case 2 was a 73-year-old male who underwent bypass surgery using a Y-shaped gastric conduit for esophageal cancer with pulmonary invasion. First, TG was simultaneously performed with ICG fluorescence following Y-shaped gastric conduit creation; subsequently, TG was performed again after the gastric conduit was placed via the subcutaneous route. As in Case 1, the TG images were consistent with the blood flow boundaries identified using ICG. Furthermore, the TG images, after the gastric conduit was placed in the neck region, showed blood flow boundaries.

Although accumulation of similar cases is necessary, TG has the potential for use as an auxiliary diagnostic tool in clinical practice. Moreover, it is highly useful for indicating the possibility of reevaluation at short intervals, which is difficult to evaluate using ICG.