Noura Alhassan, A. Sender Liberman, Patrick Charlebois, Barry L Stein, Liane S Feldman, Gerald M Fried, Carmen L Mueller, Lawrence Lee. McGill University
Introduction: High lymph node yield is associated with improved survival for colon cancer resection, however, lymphatic drainage of the colon is variable. Intraoperative identification of the lymphatic drainage patterns can allow tailoring of lymphadenectomy by determining the optimal level for vascular pedicle ligation. Immunofluorescence imaging using indocyanine-green (ICG) can be used to visualize and map the lymphatic drainage in real-time. The aim of this study was to determine the feasibility of ICG immunofluorescence for lymphatic mapping in colon cancer.
Methods: A prospective feasibility study was undertaken at a single specialized colorectal referral centre. Eligible patients included those with non-metastatic, clinical T-stage 3/4 colon adenocarcinomas undergoing elective resection, excluding those with previous colon resection. The intraoperative lymphatic mapping procedure involved peritumoral subserosal injection of 4×0.5cc ICG(25mg/10cc) at the beginning of the operation. Immunofluorescence lymphatic imaging was done at 0,10,20,and30 minutes post-injection. Complete mesocolic excision was performed regardless of lymphatic mapping results. Lymphatic drainage was classified as per the Japanese Colorectal Cancer nodal classification system and fluorescent D2/D3 nodes were sent separately for pathology. The main endpoints were feasibility(did ICG drain into lymphatic system), accuracy(were ICG ‘hotspots’ actual nodes), and potential changes in management.
Results: A total of 15 patients underwent lymphatic mapping. Mean age was 58.4 years (range 45-74); 57% were male. Failure of ICG lymphatic drainage occurred in 1 patient with bulky nodal disease(93% successful visualization of lymphatic channels). Of the 14 mapped patients, 71% had pT3-4 cancers, with 50% right-sided and 50% left-sided(Table). Immunofluorescence visualized lymphatic drainage patterns by tumor location are shown in the Table. All of the immunofluorescent ‘hotspots’ at the D3 nodal stations contained lymph nodes. The mean lymph node harvest was 28.3 nodes (SD4.8) and 3 patients had nodal metastases. All 3 of these node positive patients had lymph node involvement within an ICG-visualized drainage basin and were within the planned resection margin.
Conclusions: Based on our early experience, ICG immunofluorescence lymphatic mapping seemed to identify lymphatic drainage patterns in primary colon adenocarcinoma. This may allow for a more targeted lymphadenectomy.
ICG-visualized lymphatic drainage pattern
|Hepatic flexure/Proximal transverse||
|Splenic flexure/Distal transverse||
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 94755
Program Number: S132
Presentation Session: Colorectal III
Presentation Type: Podium