title: Laparoscopic lymph node dissection after endoscopic submucosal dissection: a novel and minimally invasive approach to treating early-stage gastric cancer.
abstract: OBJECTIVE
  Endoscopic submucosal dissection (ESD), a newly developed endoscopic mucosal resection (EMR) technique, can completely cure a differentiated mucosal gastric cancer smaller than 2 cm. For early-stage gastric cancers (EGCs) deviating from the above-mentioned criterion, gastrectomy with lymph node dissection is performed for potential risk of lymph node metastasis (LNM). However, many of surgical EGC cases actually do not have LNM, indicating this surgery may not be necessary for many cases of EGC. To avoid this unnecessary surgery, we have introduced laparoscopic lymph node dissection (LLND) after ESD. Standard gastrectomy with extended lymph node dissection is indicated for patients if LLND reveals LNM. We present our novel approach and the preliminary results of EGC patients having potential risk of LNM.
  
  
  METHODS
  Five patients with EGC deviating from the EMR criterion underwent the combination of ESD and LLND. ESD was performed using a newly developed insulation-tipped diathermic knife. Lymph nodes, which were determined on the basis of the location of the primary tumor and lymphatic drainage of the stomach, were removed laparoscopically. The lymphatic drainage was visualized by submucosally injecting indocyanine green (ICG) around the post-ESD ulcerative scars during intraoperative gastroscopy.
  
  
  RESULTS
  The ESD enabled en bloc resection without any complications. The resected margins of all the lesions were free of cancer cells vertically and horizontally. LLND was successfully performed without any complications. The mean number of the dissected lymph nodes was 15 (range 6 to 22). In 4 of the 5 patients, the dissected lymph nodes were free of cancer cells, and therefore, the combination of ESD and LLND was considered a definitive treatment. The remaining patient was found to have LNM but chose not to undergo any surgery. During follow-ups, the patients' previous quality of life was restored without any tumor recurrence.
  
  
  CONCLUSIONS
  The combination of ESD and LLND enables the complete resection of the primary tumor and the histologic determination of lymph node status. This combination treatment is a potential, minimally invasive method, and may obviate unnecessary gastrectomy without compromising curability for EGC patients having the potential risk of LNM.
authors.affiliation: Department of Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan. abentg@kyorin-kyorin-u.ac.jp
authors.forename: Nobutsugu
authors.initials: N
authors.lastname: Abe
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Mori
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Atsuko
authors.initials: A
authors.lastname: Ohki
authors.forename: Hisayo
authors.initials: H
authors.lastname: Ueki
authors.forename: Osamu
authors.initials: O
authors.lastname: Yanagida
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Masaki
authors.forename: Masanori
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Atomi
mesh_terms: D000368:Aged; D005260:Female; D005753:Gastric Mucosa / Q000601:surgery*; D005773:Gastroscopy; D006801:Humans; D010535:Laparoscopy; D008197:Lymph Node Excision / Q000379:methods*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D013274:Stomach Neoplasms / Q000473:pathology / Q000601:surgery*