Current evidence on the use of near-infrared spectroscopy for postoperative free flap monitoring: A systematic review

Abstract

Background: Although the surgical outcomes of free flap reconstruction have improved over time, vascular compromise remains a devastating complication. Near-infrared spectroscopy (NIRS) is a promising new free flap monitoring technique with the potential for better outcomes than clinical monitoring (CM). This systematic review aims to provide a comprehensive review of the current evidence regarding the use of NIRS for free flap monitoring. Methods: A systematic literature review was performed, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, on existing NRIS studies, including the clinical outcomes of NIRS monitoring, speed of detection, diagnostic accuracy, variables affecting NIRS accuracy, and cost-effectiveness. Results: A total of 24 articles were included in this analysis. In most instances of flap compromise, NIRS enabled earlier detection of compromise than did CM, by an average of 8.1 (0.5–32.0) h. The flap salvage rate of flaps monitored with CM and NIRS (87.2%) was significantly higher than that of flaps monitored with CM alone (50.0%) (P<0.01). The overall survival rate for flaps monitored with CM and NIRS (98.1%) was also significantly higher than that for flaps monitored with CM alone (96.3%) (P=0.02). Blood oxygen saturation was the only variable with a significant effect on NIRS results. Conclusion: NIRS is an objective and reliable flap monitoring technique that provides superior flap salvage and survival rates compared with CM, which translates to cost savings and a reduction in workload for healthcare staff. Further large-scale studies are needed to standardize flap compromise criterion values and efficacy for different flap types.

Keywords

• Free flap
• Flap monitoring
• Near-infrared spectroscopy
• Systematic review