How to Determine the Safety Point to Start Lymph Node Dissection of Lesser Curvature When We Perform Laparoscopy-Assisted Distal Gastrectomy

Yasushi Rino, MD, Takashi , Ohshima, MD, Kazue Yoshihara, Norio Yukawa, MD, Hitoshi Murakami, MD, Tsutomu Sato, MD, Roppei Yamada, MD, Munetaka Masuda, MD, Toshio Imada, MD. Department of Surgery, Yokohama City University, School of Medicine

Introduction
We would like to know how to determine the safety point to start lymph node dissection of lesser curvature when we perform laparoscopy-assisted distal gastrectomy (LADG).
And we investigated whether there are cancer cells or not in the blue node (BN) and the sentinel lymphaticus (SL), which is detected using sentinel node biopsy (SNB).
Methods
Technique of sentinel node biopsy
Patent blue (1%) is injected submucosally into 4 to 5 different sites at 1 mL per site around the primary tumor. Blue-stained lymphatics and lymph nodes can be seen by turning over the greater omentum and lesser omentum extraperitoneally 7). If blue nodes or lymphaticus are found, biopsy is performed at this point.
Subjects
The study was conducted in 12 patients with a preoperative diagnosis of T1 tumor invasion and N0 that is no lymph node metastasis. Informed consent was obtained from the patients for SNB after patent blue staining and investigation of CEAmRNA and CK20mRNA. There were 10 males and 2 females with a mean age of 64.6 years. Tumor location was M, and L for 6, and 6 patients, respectively. Tumor invasion of m, sm, mp, and ss was identified in 5, 5, 0, and 2 patients, respectively. 12 patients underwent LADG.
Results
Of the 12 patients in whom BN and SL were identified, 1 (8.3%) had positive CEAmRNA and positive CK20mRNA of SL.
Discussion
Our present study shows the possibility of existence of cancer cells in the SL from the tumor to BN. From this result, we determine the safety point to start lymph node dissection of lesser curvature using SNB too avoid the cut of SL.