Published online Dec 14, 2022. doi: 10.3748/wjg.v28.i46.6564
Peer-review started: August 24, 2022
First decision: September 2, 2022
Revised: September 22, 2022
Accepted: November 22, 2022
Article in press: November 22, 2022
Published online: December 14, 2022
Processing time: 106 Days and 5.1 Hours
Although endoscopic ultrasound (EUS) is a method to predict the depth of invasion in early gastric cancer (EGC), it is still difficult to differentiate between T1a and T1b EGCs via EUS.
In particular, we considered a method to increase the accuracy of diagnosis for endoscopists who are beginning to perform EUS. It was thought that submucosal saline injection (SSI) during endoscopic mucosal resection may be helpful for examination because it can expand the submucosal layer.
The objectives of this study was to confirm whether SSI could be a method to improve the accuracy of EUS in distinguishing T1a and T1b lesions even in EGC and determine the feasibility of EUS for beginners.
During March-April 2019, 24 endoscopically diagnosed EGC lesions in 24 patients were examined by EUS. All patients underwent standard EUS followed by EUS with SSI (EUS-SSI). Thereafter, endoscopic or surgical resection was performed within 7 days. T1a and T1b lesions were diagnosed based on the final pathology results after treatment. The diagnostic accuracy of EUS and EUS-SSI for T stage was compared.
Standard EUS identified 6 of 13 T1a cancer patients and 3 of 10 T1b cancer patients. Whereas, EUS-SSI identified 12 of 13 T1a cancer patients and 6 of 10 T1b cancer patients. In this study, SSI combined EUS was more accurate than EUS alone in diagnosing T1a and T1b lesions of EGC (75.0% and 37.5%, respectively).
SSI improved the diagnostic accuracy of EUS in distinguishing between the T1a and T1b stages in EGC in this study. However, this needs to be confirmed in large-scale, prospective, randomized clinical trials in the future.
In our study, SSI improved the diagnostic accuracy of EUS in distinguishing between the T1a and T1b stages in EGC. In particular, we suggest that beginners who are beginning EUS should try the EUS-SSI method when evaluating the depth of invasion of gastric cancer. However, our study is a clinical study conducted at a single institution, and the sample size is small. Therefore, a large-scale, prospective, randomized clinical trials for this are needed in the future.