Image-Guided Robotic Surgery for Sentinel Lymph Node Status Assessment in Uterine Cancers Using Ultrasound Drop-in Probe: Surgical Technique in 10 Steps

IntroductionRecent guidelines recommend the sentinel lymph node (SLN) technique in uterine cancers, as it is associated with lower perioperative complications.1 Image-guided surgery can address some limitations of SLN procedures, such as low frozen-section accuracy and risk of empty packets,2, 3-4 by providing real-time lymph node assessment.5,6 This video describes the surgical procedure of intraoperative robotic ultrasound examination for SLN assessment.Materials and MethodsThe Arietta L43K (2-12 MHz, Hitachi, Japan) drop-in robotic ultrasound probe was used to assist with SLN dissection. The procedure was performed on the da Vinci Xi platform. The probe, introduced through an accessory trocar, was manipulated by robotic instruments, providing real-time ultrasound imaging in split-view mode on the surgeon's console. Ultrasound images, captured by the surgeon under the guidance of an experienced ultrasound examiner, were analyzed both in vivo and ex vivo.7ResultsThe procedure involves ten steps, detailed as follows. (1) The procedure begins with the cervical injection of indocyanine green. (2) The pelvic retroperitoneum is opened to allow access to anatomical landmarks. (3) Using near-infrared imaging mode, the lymphatic pathways are highlighted, allowing for the identification of the SLN. (4) Once identified, the drop-in ultrasound probe is introduced. (5) The console is switched to split-view mode, enabling the surgeon to observe ultrasound images alongside the endoscopic view. (6) In vivo imaging is conducted. (7) Both images and videos of the lymph node are captured. (8) The SLN is subsequently dissected. (9) SLN specimens are safely extracted. (10) Ex vivo ultrasound assessment is performed to further evaluate their characteristics.ConclusionsAlthough its accuracy compared with histology as the gold standard is yet to be demonstrated, image-guided robotic lymph node ultrasound is a feasible and promising procedure for real-time SLN assessment. A prospective study is ongoing (R-LYNUS, NCT06621823) to clinically validate this technique.