To investigate the method and efficacy of robot-assisted modified antegrade inguinal lymphadenectomy guided by indocyanine green (ICG) fluorescence imaging in patients with penile cancer.

The clinical data of 4 patients with penile cancer from June 2022 to July 2024 were retrospectively analyzed. The median age of the 4 patients was 61.5 years, ranging from 52 to 72 years. Clinical stage: 4 cases were T₁ (subcutaneous connective tissue invasion), preoperative physical examination and auxiliary examination showed inguinal lymph node enlargement, of which 1 case showed left pelvic lymph node enlargement, including 2 cases of N₁ stage, 1 case of N₂ stage and 1 case of N₃ stage. No distant metastasis was observed. Surgical methods: the patient was placed in the supine position, and ICG was injected into the root of the penis before operation. Precise inguinal lymphadenectomy and pelvic lymphadenectomy were performed under the guidance of ICG.

All operations were successfully completed without conversion to open surgery and without the need for mobile robotic arm system. In one case, the original cannula position was used to enter the abdominal cavity, and pelvic lymphadenectomy was performed at the same time. A total of 8 operations and 1 pelvic lymphadenectomy were performed in 4 patients. The median operation time of each side was 60 min, ranging from 50 to 70 min. The intraoperative blood loss was less than 10 ml on each side. The median number of left lymph nodes dissected was 4, ranging from 3 to 14. The median number of right lymph nodes dissected was 4, ranging from 2 to 9. Stitchings were removed in all the 4 cases within 10 days after operation, and no complications such as skin necrosis, delayed wound healing, and cellulitis occurred. The drainage tube removal time of 4 cases ranged from 5 to 40 days, with a median time of 11 days. One of them had lymphatic leakage in the inguinal region and delayed removal of the tube. All patients were followed up for 5-25 months, and no tumor recurrence or metastasis was found in the primary tumor, inguinal and pelvic lymph nodes.

Robot-assisted modified anterograde inguinal lymphadenectomy under the guidance of ICG fluorescence can accurately distinguish the location of lymph nodes and separate them from the surrounding tissues, significantly improve the efficacy of inguinal lymph node dissection and reduce the incidence of postoperative complications.