Yuki Maeda

Usefulness of the thread-traction method in esophageal endoscopic submucosal dissection: Randomized controlled trial

To assess the usefulness of the thread‐traction method (TT method) in esophageal endoscopic submucosal dissection (ESD).

Mediastinal emphysema after esophageal endoscopic submucosal dissection: its prevalence and clinical significance.

Aims:  To assess the prevalence and clinical significance of mediastinal emphysema (ME) after esophageal endoscopic submucosal dissection (ESD).

Efficacy of acetic acid-spraying method in diagnosing extension of barrett's cancer under the squamous epithelium

Aim:  Endoscopic diagnosis of the lateral extension of Barretts cancer under the squamous epithelium (BCUS) is sometimes difficult because the cancer is unobservable in the esophageal lumen. The aim of the present study was to clarify the endoscopic features of the extension of BCUS and verify the usefulness of the acetic acid‐spraying method (AAS) for diagnosis.

Carbon dioxide insufflation in esophageal endoscopic submucosal dissection reduces mediastinal emphysema: A randomized, double-blind, controlled trial

AIM To assess the efficacy of CO2 insufflation for reduction of mediastinal emphysema (ME) immediately after endoscopic submucosal dissection (ESD). METHODS A total of 46 patients who were to undergo esophageal ESD were randomly assigned to receive either CO2 insufflation (CO2 group, n = 24) or air insufflation (Air group, n = 22). Computed tomography (CT) was carried out immediately after ESD and the next morning. Pain and abdominal distention were chronologically recorded using a 100-mm visual analogue scale (VAS). The volume of residual gas in the digestive tract was measured using CT imaging. RESULTS The incidence of ME immediately after ESD in the CO2 group was significantly lower than that in the Air group (17% vs 55%, P = 0.012). The incidence of ME the next morning was 8.3% vs 32% respectively (P = 0.066). There were no differences in pain scores or distention scores at any post-procedure time points. The volume of residual gas in the digestive tract immediately after ESD was significantly smaller in the CO2 group than that in the Air group (808 mL vs 1173 mL, P = 0.013). CONCLUSION CO2 insufflation during esophageal ESD significantly reduced postprocedural ME. CO2 insufflation also reduced the volume of residual gas in the digestive tract immediately after ESD, but not the VAS scores of pain and distention.

Reply to the letter to the editor: Lymph node metastasis of adenocarcinoma and different definitions of sm1 cancer in the esophagus

Ryu Ishihara • Tsuneo Oyama • Seiichiro Abe • Hiroaki Takahashi • Hiroyuki Ono • Junko Fujisaki • Mitsuru Kaise • Kenichi Goda • Kenro Kawada • Tomoyuki Koike • Manabu Takeuchi • Rie Matsuda • Dai Hirasawa • Masayoshi Yamada • Junichi Kodaira • Masaki Tanaka • Masami Omae • Akira Matsui • Takashi Kanesaka • Akiko Takahashi • Shinichi Hirooka • Masahiro Saito • Yosuke Tsuji • Yuki Maeda • Hiroharu Yamashita • Ichiro Oda • Yasuhiko Tomita • Takashi Matsunaga • Shuji Terai • Soji Ozawa • Tatsuyuki Kawano • Yasuyuki Seto

Short-term outcomes of multicenter prospective cohort study of gastric endoscopic resection: ‘Real-world evidence’ in Japan

A Japanese multicenter prospective cohort study examining endoscopic resection (ER) for early gastric cancer (EGC) has been conducted using a Web registry developed to determine the short‐term and long‐term outcomes based on absolute and expanded indications. We hereby present the short‐term outcomes of this study.

Submucosal fibrosis detected by endoscopic ultrasonography may predict incomplete endoscopic submucosal dissection

Endoscopic ultrasonography (EUS) can visualize the layer structure of the gastric wall and it can detect changes resulting from ulcer scarring. EUS evaluation of ulcer scarring can predict the difficulty of endoscopic submucosal dissection (ESD) preoperatively. Figure 1a is a chromoendoscopic image of a local recurrence lesion of cancer after ESD. Preoperative EUS revealed interruption of the third layer and thickening of the fourth layer (UL-IIIs) (Fig. 1b). ESD was done and fibrotic changes in the submucosal layer were so severe that the resected specimen suffered a tear (Fig. 1c). This lesion was diagnosed as mucosal cancer histologically. However, the lateral/vertical margins at the tear could not be ascertained. Two years after ESD, a flat elevated lesion recurred at the scar (Fig. 2). This case shows that local recurrence resulting from imprecise pathological assessment because of a lack of sufficient tumor tissue or a burn artifact can occur when the specimen has been damaged, even if en bloc resection is achieved. In our center, 794 cases of early gastric cancer (EGC) underwent ESD from 2005 to 2009. Among them, 26 lesions were incompletely resected because of severe ulcer scarring. Interruption of the third layer in almost all cases (24 lesions) was shown by preoperative EUS, possibly suggesting imprecise histological assessment of ESD specimens such as damage to the specimens or piecemeal resection. We consider that surgery is more preferable than ESD for EGC with an interruption of >5 mm of the third layer. However, this result does not mean that lesions with interruption of the third layer should not be treated by ESD because there are no data on EUS findings of completely resected lesions. In the future, EUS findings of cases of complete resection should also be evaluated in order to validate the usefulness of EUS in preoperative evaluation for EGC with ulcer scarring.