Prolonged and severe tissue hypoxia results in tissue necrosis in pedicled flaps. We demonstrate the potential of near-infrared spectroscopy for predicting viability of compromised tissue portions. This approach clearly identifies tissue regions with low oxygen supply, and also the severity of this challenge, in a rapid and non-invasive manner, with a high degree of reproducibility. Tissues remaining below a certain hemoglobin oxygen saturation threshold (oxygen saturation index < 1) for prolonged periods (> 6h) became increasingly dehydrated, eventually becoming visibly necrotic. Tissues above this threshold (oxygen saturation index > 1), despite being significantly hypoxic relative to the pre-elevation saturation values, remained viable over the 72 h post-elevation monitoring period. The magnitude of the drop in tissue oxygen saturation, as observed immediately following surgery, correlated with the final clinical outcome of the flap tissue. These results indicate the potential of near infrared spectroscopy and imaging to monitor tissue oxygenation status and assess tissue viability following reconstructive surgery. Early, nonsubjective detection of poor tissue oxygenation following surgery increases the likelihood that intervention aimed at saving the tissue will be successful.Une hypoxie tissulaire grave et prolongée provoque une nécrose tissulaire dans des lambeaux pédiculés. Cette invention démontre le potentiel de la spectroscopie en proche infrarouge qui permet de prévoir la viabilité de morceaux de tissus affaiblis. Cette approche identifie clairement des zones de tissus faiblement alimentées en oxygène, et également la gravité de cette situation, dune manière rapide et non envahissante et avec un degré élevé de précision. Les tissus restant au dessous dun certain seuil de saturation en oxygène de lhémoglobine (indice de saturation en oxygène ∫1) au cours de périodes prolongées (⊃6 heures) sont devenus de plus en plus déshydratés, devenant éventuellement vi
