Clinical Validation of Near Infrared Spectroscopy for Free Flap Monitoring and Establishing Intervention Thresholds
Sean Zhong Jin Neo1, Yu-Hsin Yen2, Ashley Shi Hui Lee3
1Department of Plastic, Reconstructive and Aesthetic Surgery, Singhealth.
Annals of Plastic Surgery
|July 24, 2026
Summary
Near-infrared spectroscopy (NIRS) monitoring improves free flap survival by enabling earlier detection of vascular compromise. This technology enhances salvage rates and reduces flap failure in reconstructive surgery.
Area of Science:
- Plastic Surgery
- Vascular Surgery
- Biomedical Engineering
Background:
- Free flap failure due to microvascular thrombosis is a major surgical complication.
- Early detection of vascular compromise is crucial for successful flap salvage.
- Current monitoring relies on standard clinical assessment, which may have limitations.
Purpose of the Study:
- To evaluate the effectiveness of near-infrared spectroscopy (NIRS) for postoperative free flap monitoring.
- To compare flap outcomes between NIRS monitoring and standard clinical assessment.
- To identify an objective threshold for NIRS-detected vascular compromise.
Main Methods:
- Retrospective cohort study of 932 free flaps over four years.
- 302 flaps were monitored with Masimo's O3® Regional Oximetry (NIRS) alongside clinical assessment.
- Outcomes analyzed: re-exploration, flap failure, and salvage rates.
Main Results:
- Flaps monitored with NIRS showed higher salvage rates and lower failure rates.
- NIRS use was independently associated with improved flap survival.
- A 22.5% drop in regional oxygen saturation predicted flap compromise with good accuracy.
Conclusions:
- Adjunctive NIRS surveillance is a reliable method for postoperative free flap monitoring.
- NIRS provides objective data to aid clinical decision-making in detecting vascular compromise.
- NIRS monitoring can significantly improve free flap outcomes in reconstructive surgery.
