Fluorescent indocyanine green angiography: preliminary results in microsurgery monitoring

Pedicled flaps and free-tissue transfer flaps are used routinely to reconstruct head and neck, limb, hand, thoracic and abdominopelvic hard and soft tissue defects. But failure remains a constant concern.

Usually failure is due to blood supply compromise. To detect vascular complication clinical monitoring, based on subjective criteria, remains the gold-standard. Clinical monitoring can be improved by many intraoperative and postoperative monitoring devices. These noninvasive and invasive devices help prevent and identify vascular occlusion, with varying degrees of success. None of these devices are universally adopted. Noninvasive techniques include hand-held Doppler ultrasound, infrared thermography, polarized spectral imaging, and laser Doppler perfusion imaging.

Indocyanine green (ICG), a fluorescent dye, has been used for more than 40 years for cardiac output, liver function, neurosurgery, ophthalmology and digestive surgery. ICG is a water-soluble dye that absorbs light in the near-infrared spectral range, with a peak at 805 nm, and emits fluorescence at 835 nm. ICG completely binds to plasma proteins after intravenous injection, and is exclusively distributed in the intravascular space (6). ICG has a short plasma half-life of 3.4 minutes. That allows repeated injections without reaching toxic levels. IGC is cleared from blood by the liver and excreted into the bile. Adverse effects are rare (anaphylactic shock, hypotension, dyspnea, nausea, exanthema, and pruritus). These properties make it a suitable tracer for vessel perfusion.

The fluorescent indocyanine green angiography (FA ICG) has been used in thyroid surgery, in sentinel node procedure (breast cancer).

The objective of this study is to evaluate preliminary the results of the fluorescent indocyanine green angiography in free flaps procedures.

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