Category: Robotic Surgery: Lower Tract - Malignant
Introduction & Objective :
Extended pelvic lymph node dissection (ePLND) during robot assisted radical prostatectomy (RARP) still have certain considerations to address, such as appropriate resection field and longer operative. Recently, indocyanine green (ICG) fluorescence imaging (FI) guided method have reported the feasibility and safety of detection of lymph node (LN) metastasis in prostate cancer. The objectives of this study are to analyze lymphatic drainage patterns, to evaluate quality improvement of ePLND with ICG-FI through direct vision of lymphatic vessels and ICG fluorescent LN (F-LN) and to confirm whether F-LNs available for the sentinel lymph node (SLN) method.
After review board approval, 51 cases with ICG-FI guided ePLND were performed from July 2017 to March 2018. Firefly® on the da Vinci Xi® system was used for near-infrared fluorescence system. ICG solution (0.05-1.0mg/mL) were injected 4mL to the prostate with transrectal ultrasound sonography before each surgery. Lymphatic drainage patterns and pathological findings were then recorded. Resected LN numbers were compared with conventional ePLND cases performed just before introduction of ICG-FI.
We identified lymphatic drainage route and F-LNs about 90% of cases in right and left side. Main route was paravesical artery site (first landing site around vesical arteries), internal route (from inside of internal iliac artery to external iliac region) and lateral route (from paravesical site to obturator region). Resected lymph nodes (LN) were increased from 19.5 in conventional ePLNDs and 24.0 with ICG-FI (p=0.008). Metastasis were shown in 9 cases (17.6%), 19 regions. F-LNs were not always considered as SLN because 63.2% of regions were unmet for SLN.
Conclusions : Lymphatic drainage pathways correlated mainly to internal iliac artery lesions as found in previous reports. Lymph nodes yield numbers showed some increase with ICG injection compared to those of the conventional procedure. ICG stained nodes were often found around inferior vesical artery or presacral lesions that were not contained in conventional ePLNDs. These findings could contribute towards quality improvement of ePLNDs during RARP. High quality ePLND during RARP for high risk Pca patients is still considered to be the standard approach.
Assistant Chief of Staff
Department of Urology, St. Luke's International Hospital
Tokyo, Tokyo, Japan