Submucosal Saline Injection Followed by Endoscopic Ultrasound

Diagnostic accuracy for T1a and T1b staging

Endoscopic ultrasound (EUS) is unsatisfactory in distinguishing between T1a and T1b stage
 esophageal squamous cell carcinoma (ESCC). Consequently, the National Comprehensive Cancer
 Network guidelines recommend endoscopic resection (ER) as a diagnostic tool for substaging T1
 stage ESCC. However, as an invasive approach, diagnostic ER is not an optimal approach
 especially for T1b cases as most of them might not be fully cured by ER. It is necessary to
 develop reliable and less invasive methods to distinguish between T1a and T1b stage ESCC. In
 our previous unicentral trial, we found that submucosal saline injection (SSI) significantly
 improved the diagnostic accuracy of EUS in differentiating between T1a and T1b stage ESCC. It
 can be used as an alternative to diagnostic ER for preoperative substaging T1 stage ESCC
 cases in remote regions where few endoscopists are able to perform diagnostic ER. The use of
 EUS and SSI would help T1b stage patients avoid invasive diagnostic ER.
 
 Therefore, we aim to conduct a multi-center clinical trail to examine whether SSI can improve
 traditional EUS accuracy in distinguishing between T1a and T1b stage ESCC.