The IntAct Trial: ICG Fluorescence Angiography in Rectal Cancer Surgery

The IntAct trial investigated the use of indocyanine green (ICG) fluorescence angiography as a tool to reduce anastomotic leaks during rectal cancer surgery. Anastomotic leaks, which occur when the surgical connection between two sections of the bowel fails, are a significant complication in rectal cancer surgery, leading to increased morbidity, prolonged hospital stays, and higher healthcare costs.

### Key Findings of the IntAct Trial:

1. **Primary Outcome:**

• The trial aimed to determine whether ICG fluorescence angiography could significantly reduce clinical anastomotic leaks. However, the reduction in clinical leaks was not statistically significant.

2. **Overall Leak Reduction:**

• Despite the primary outcome not reaching statistical significance, the use of ICG fluorescence angiography was associated with a reduction in the overall number of anastomotic leaks, particularly in less severe grades (grades A and B).

3. **Intraoperative Adjustments:**

• Surgeons using ICG fluorescence angiography made more intraoperative adjustments to improve the perfusion of the anastomosis. This suggests that the technique provided valuable real-time feedback on blood flow, allowing surgeons to optimize the surgical connection.

4. **Postoperative Outcomes:**

• Postoperative outcomes, including quality of life and mortality, were similar between the ICG group and the control group. This indicates that while ICG may help reduce certain complications, it did not significantly impact broader postoperative recovery metrics.

5. **Cost-Effectiveness:**

• The trial found modest cost savings associated with ICG use, suggesting that the technique could be cost-effective. By potentially avoiding some anastomotic leaks, hospitals may reduce the need for additional interventions and extended hospital stays.

6. **Severe Leaks:**

• The study noted that severe leaks (grade C) are likely influenced by factors beyond perfusion, such as patient comorbidities, surgical technique, or underlying disease biology. As a result, ICG fluorescence angiography may be less effective in preventing these more severe complications.

### Implications of the IntAct Trial:

The IntAct trial highlights the potential benefits of ICG fluorescence angiography in rectal cancer surgery, particularly in reducing less severe anastomotic leaks and providing intraoperative guidance for surgeons. However, its impact on clinical leak rates overall and severe leaks was limited. The technique may still be a valuable tool in the surgical armamentarium, especially given its potential cost-effectiveness and ability to improve perfusion during surgery.

Future research may focus on refining the use of ICG, identifying patient populations that would benefit most, and addressing factors contributing to severe leaks.