Fluorescence imaging‐guided pelvic lymph node localization and resection of bladder cancer after intracutaneous injection of indocyanine green into the lower limbs and perineum

Pelvic lymph node dissection (PLND) in radical cystectomy (RC) is of great significance, but the method and scope of PLND remain controversial. Based on the principle of indirect lymphadenography, we designed a method to localize the whole pelvic lymph nodes by intradermal injection of indocyanine green (ICG) through the lower limbs and perineum, and to evaluate the effectiveness of this method.In a single center, 54 bladder cancer patients who underwent RC and PLND participated in a prospective clinical trial, which began on February 28, 2022 and ended on December 30, 2022. ICG solution was injected subcutaneously at the medial malleolus of both lower extremities and at both sides of the midline of the perineum. The fluorescent laparoscopy was used to trace, locate, and remove the targeted areas under the image fusion mode. The consistency of lymph node resection was determined by histopathological diagnosis. The impact of ICG guidance on the surgical time of PLND was compared with that of 11 bladder cancer patients who underwent RC and PLND without ICG injection, serving as the control group.Perineal lower limb combined injection can provide comprehensive visualization of pelvic lymph nodes. This technique reduces PLND surgical time and increases the accuracy of PLND.Intracutaneous injection of ICG into the lower limbs and perineum can specifically mark pelvic lymph nodes. Intraoperative fluorescence imaging can accurately identify, locate, and resect lymph nodes in the pelvic region, reducing PLND surgical time and increasing the accuracy of PLND.