The Comparison Between Low- and High-Concentration Injection Solution Ability for Colorectal Endoscopic Submucosal...

Injection solution is important for achieving submucosal elevation in endoscopic submucosal dissection (ESD) and various viscous solutions categorized as low-concentration injection solution (LCS) or high-concentration injection solution (HCS) are used. We analyzed the difference between LCS and HCS in colorectal ESD.

This was a prospective, randomized controlled trial at six Japanese institutions. Patients with early neoplastic lesions of ≥ 20 mm were enrolled from March 2022 to September 2023. Sodium alginate (Liftal K, Kaigen Pharma Co., Osaka, Japan) was used as the injection solution, and the concentration of HCS and LCS was set at 0.6% and 0.3%, respectively. Participants were randomized to HCS or LCS groups and the primary endpoint was the noninferiority about ESD procedure time of LCS compared to HCS.

The LCS and HCS groups consisted of 79 and 82 cases, respectively. The ESD procedure time (min, mean ± standard deviation) was significantly noninferior between the LCS and HCS groups (p < 0.001) and was significantly shorter in the LCS group than in the HCS group (61.9 ± 39.2 vs. 76.9 ± 67.5, p = 0.044). There were no significant differences in en bloc resection (98.7% vs. 100.0%, p = 0.985), perioperative perforation (2.5% vs. 2.4%, p = 0.639), and delayed bleeding (1.3% vs. 1.2%, p = 0.493). In the subgroup analysis, the ESD procedure times were significant for lesions of ≥ 40 mm (74.3 ± 30.4 vs. 125.3 ± 107.2, p = 0.031) and experts (51.5 ± 29.2 vs. 69.4 ± 58.9, p = 0.046). Additionally, injection volumes (mL) were not significant (38.0 ± 20.2 vs. 33.0 ± 27.0, p = 0.098) in the two groups.

LCS was noninferior to HCS in terms of procedure time and significantly reduced it.

University Hospital Medical Information Network Clinical Trials Registry number: UMIN000048661.