Evaluating SnapshotNIR for Tissue Oxygenation Measurement Across Skin Types After Mastectomy

Area of Science:

• Biomedical Engineering
• Surgical Oncology
• Medical Imaging

Background:

• Accurate monitoring of mastectomy skin flap (MSF) perfusion is crucial for patient outcomes.
• Tissue ischemia in MSF can be difficult to detect, particularly in patients with darker skin pigmentation.
• Near-infrared spectroscopy (NIRS) offers real-time tissue oxygen saturation (StO₂) measurement but requires validation across diverse skin tones.

Purpose of the Study:

• To evaluate the accuracy of SnapshotNIR NIRS device for measuring MSF perfusion across different skin pigmentation levels.
• To determine the impact of Fitzpatrick skin pigmentation scores on NIRS measurements of tissue oxygenation.
• To identify potential biases in NIRS readings related to skin tone.

Main Methods:

• A quasi-experimental study involving 33 patients undergoing mastectomy.
• Measurement of MSF edge ΔStO₂ (preoperative minus postoperative StO₂) using the SnapshotNIR device.
• Analysis of ΔStO₂ in correlation with Fitzpatrick skin pigmentation scores.

Main Results:

• A significant negative correlation was observed between Fitzpatrick scores and ΔStO₂ (ρ = -0.392, p = 0.016).
• Tissue oxygenation measurements (ΔStO₂) progressively decreased with increasing Fitzpatrick scores, indicating a shift from oxygenation increase to decrease.
• Significant differences in ΔStO₂ were found between lighter and darker skin pigmentation groups (Fitzpatrick scores 1 vs. 5 and 2 vs. 5).

Conclusions:

• SnapshotNIR technology can detect changes in StO₂ and predict ischemia.
• NIRS devices may overestimate tissue oxygenation in individuals with darker skin pigmentation.
• Calibration of NIRS devices is necessary to ensure accurate perfusion monitoring across all skin tones.