[Development of Intraoperative Near-infrared Fluorescent Ureteral Imaging Agent to Prevent Iatrogenic Ureteral Injury].

Abstract

The adult ureter is a delicate structure with an approximate internal diameter of 5 mm located deep within the lower abdomen and surrounded by various tissues. Therefore, due to its positioning, visual identification of the ureter is challenging. Iatrogenic ureteral injuries, which can lead to severe illness, occur during both open and laparoscopic abdominal surgeries, posing a serious clinical concern. Reliable intraoperative identification of the ureters is essential to prevent inadvertent injuries. Ureteral stenting or catheter placement, commonly used procedure for ureteral identification, involve insertion via the urethra and bladder. However, these techniques have limitations, including prolonged surgery time, risk of urinary tract complications, limited diagnostic capability for ureteral injury, and higher medical costs. Optical imaging has the potential to assist in surgeries involving invisible tissues. Recently, novel fluorescent compounds, ASP5354, ZW800-1, and IS-001, has entered phase 3 clinical trials for intravenous use in intraoperative ureteral identification and injury diagnosis. These compounds possess a heptamethine cyanine skeleton that generates near-infrared fluorescence (700-900 nm), exhibit excellent tissue permeability, enable ureteral visualization throughout minimally invasive laparoscopic procedures, and are safe and well tolerated. Notably, no adverse events have been reported in clinical trials to date. This review provides an overview of these promising compounds and their potential effect in improving surgical outcomes.