Near Infrared Fluorescent Dyes

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Introduction: Retained surgical items (RSIs), specifically surgical sponges, are a reoccurring problem following surgical procedures. When unintentionally left in patients, surgical items have severe health, monetary, and morale-related repercussions for patients and healthcare providers. Retained surgical sponges account for 70% of all RSI cases with a minimum of 13,000-234,000 incidences occurring globally and costing over $2 billion in the US alone, on an annual basis. Aside from the counting of surgical items, which is time-consuming and prone to human error, other typical methods for detecting RSIs include X-ray imaging, radio-frequency identification (RFID), and data-matrix-coded (DMC) tags. Although these methods aid in limiting the cases of RSIs, they have their own shortcomings. Detection using X-ray tags embedded in the surgical items unnecessarily exposes patients to radiation and also yields false negatives in 10-30% of RSI cases, and use of RFID and DMC tags are 10 times more expensive. Even MRI can be inadequate in discovering items that can absorb moisture in the body. Therefore, a safe, fast, effective and cost-conscious methodology is needed for monitoring RSI during or immediately after surgery. Technology: Georgia State University researchers have invented a novel near-infrared (NIR)-based method for intraoperative RSI detection. The approach uses the NIR fluorescence properties of polymethine cyanine/squarylium dyes by exploiting their inherently advantageous photophysical properties. The unique properties of the proposed tagging agents allow surgical items embedded with FDA approved NIR dyes to be easily differentiated against the body�s natural biomolecules when viewed with an NIR detector. The dyes can be detected by using a simple low-cost imaging detector that projects the image onto a computer monitor where the surgeon can check for RSI by a simple glance before closing the surgical field. NIR light is non-ionizing radiation that is invisible to human eye and yet most human tissues are transparent to it, allowing for visualization through blood and some solid organs. This RSI detection method offers a reliable and safe approach that is universally adaptable for every surgical procedure.