Intraoperative Near-infrared Spectroscopy Can Predict Skin Flap Necrosis
SnapshotNIR uses NIR (near-infrared) light to determine tissue oxygenation saturation (StO2) and hemoglobin levels, key indicators of tissue health. The use of NIRS intraoperatively to augment the clinical examination of tissue perfusion can help guide management.
Study completed by W.F. Hill, MD, K. Kinaschuk, MD, C. Temple-Oberle, MD, MSc, FRCSC.
Hill, W.F. MD*; Kinaschuk, K. MD†; Temple-Oberle, C. MD, MSc, FRCSC*,‡. Intraoperative Near-infrared Spectroscopy Can Predict Skin Flap Necrosis. Plastic & Reconstructive Surgery-Global Open 12(3):p e5669, March 2024. | DOI: 10.1097/GOX.0000000000005669
Publication in Plastic & Reconstructive Surgery-Global Open
Background:
This prospective cohort study assessed tissue oxygen saturation (StO2) intraoperatively in 102 patients (67 female; 35 male) during breast reconstructions. The procedures were 38 alloplastic reconstructions, 8 free flaps, 42 local/regional skin flaps, 13 pedicled flaps, and 1 free flap with 18 patients (17.6% of cohort, 13 female patients) developing skin flap necrosis. Each intraoperative image was stratified into areas of i) control tissue, ii) areas at risk of necrosis, and iii) areas of skin flap necrosis that developed.
Results:
There was a significant reduction in StO2 from control areas (74.8%) and areas at risk of necrosis (70.9%) to areas that had skin flap necrosis (54.3%). In patients who developed skin flap necrosis, an intraoperative StO2 value <60% gave rise to necrosis 96% of the time. Conversely, an intraoperative StO2 value >85% was associated with necrosis not developing 96% of the time.
Clinician Corner:
This study highlights that necrosis is likely to occur when StO2 <60% in Caucasian patients and immediate intraoperative intervention (e.g., topical nitroglycerin, trimming skin edges of flaps, consider tissue expander to decrease volume in direct to implant cases) may be a suitable course of action to restore local blood flow and oxygen tensions. Conversely, areas of high StO2 (>85%) are not likely to develop necrosis. Thus, this study supports point-of-care intraoperative imaging to quickly assess relative risk for skin flap necrosis and provide key indicators of tissue viability thereby allowing clinicians to respond to physiological concerns before they progress to necrosis.