Prospective randomized trial comparing conventional and underwater endoscopic submucosal dissection for superficial colorectal neoplasms.

This study compared procedure-related outcomes of conventional and underwater endoscopic submucosal dissection (ESD) for superficial colorectal neoplasms (SCNs).In this single-center, randomized controlled trial, patients with SCNs meeting the indications of the Japanese guidelines for ESD were randomly assigned to undergo conventional ESD (CESD) or underwater ESD (UESD) performed by an expert. The primary endpoint was dissection speed, defined as the specimen area per ESD time.We analyzed the data of 69 and 70 CESD and UESD cases, respectively; however, no significant differences were found in median dissection speed (17.4 and 19.9 mm2/min, respectively; P=0.19). Multiple regression analysis revealed that the suitable positional relationship between the lesion and the direction of gravity (nongravity side for CESD and gravity side for UESD) was independently and positively associated with dissection speed (P<0.001). En bloc resection was achieved without perforation in all cases. The incidence of post-ESD coagulation syndrome was not significantly different between the two groups (4.3% vs. 2.9%, respectively; P=0.68).UESD did not expedite dissection speed in the overall patient population. CESD and UESD may be complementary in the colorectum depending on the positional relationship between the lesion and the direction of gravity.

Nagata M ，Namiki M ，Fujikawa T ，Munakata H ... -  《-》

Comparing underwater endoscopic submucosal dissection and conventional endoscopic submucosal dissection for large laterally spreading tumor: a randomized controlled trial (with video).

Colorectal endoscopic submucosal dissection (ESD) is challenging despite its usefulness. Underwater ESD (UESD) provides better traction and a clearer view of the submucosal layer than conventional ESD (CESD). This study compared the efficiency of UESD and CESD for large (20-50 mm) laterally spreading tumors (LSTs). Preplanned sample size was calculated from our previous experience. As a result, 28 patients were required for the UESD group and CESD group each. The primary outcome was total procedure time; the secondary outcome was dissection speed. Fifty-six patients were enrolled, and a total of 28 patients were assigned to each group. The mean LST size was 31.6 mm and 31.3 mm in the UESD and CESD groups, respectively. Fibrosis was observed in 67.9% and 60.7% of patients in the UESD and CESD groups. Total procedure time (mean ± standard deviation) for the UESD group was significantly shorter than that for the CESD group (49.5 ± 20.3 minutes vs 75.7 ± 36.1 minutes; mean difference, -26.2 minutes; 95% confidence interval, -42.0 to -10.5 minutes). Dissection speed of the UESD group was significantly faster than that of the CESD group (21.9 ± 6.9 mm2/min vs 15.2 ± 7.3 mm2/min; mean difference, 6.7 mm2/min; 95% confidence interval, 2.8 to 10.4 mm2/min). There was no difference between groups in the R0 resection rate or en bloc resection rate. No perforations were observed in either group. UESD was superior to CESD in total procedure time and dissection speed. UESD can be recommended as the preferred method for the resection of large LSTs.

Oh CK ，Chung HH ，Park JK ，Jung J ，Lee HY ，Kim YJ ，Kim JB ... -  《-》

Underwater versus conventional endoscopic submucosal dissection for colorectal lesions: systematic review and meta-analysis.

Effect of underwater endoscopic submucosal dissection (UESD) on clinical outcomes as compared with conventional ESD (CESD) remains unclear. We conducted a meta-analysis of the available data. Online databases were searched for studies comparing UESD with CESD for colorectal lesions. The outcomes of interest were en-bloc resection, R0 resection, procedure time (minutes), dissection speed (mm2/min), and adverse events. Pooled odds ratios (ORs) and standardized mean difference (SMD), along with 95% confidence intervals (CIs) were calculated. Seven studies with 1401 patients (UESD, 452; CESD, 949) were included. Mean patient age was 69 years, and 57% of patients were men. UESD had both a shorter procedure time (SMD, -1.33; 95% CI, -2.34 to -.32; P = .010) and greater dissection speed (SMD, 1.01; 95% CI, .35-1.68; P = .003) when compared with CESD. No significant differences were observed between the 2 groups with respect to en-bloc resection (OR, 1.13; 95% CI, .37-3.41), R0 resection (OR, 2.36; 95% CI, .79-7.05), delayed bleeding (OR, 1.34; 95% CI, .65-2.74), perforation (OR, 1.13; 95% CI, .64-2.00), and postresection electrocoagulation syndrome (OR, .38; 95% CI, .10-1.42). UESD was faster in patients with colorectal lesions but had comparable rates of en-bloc resection, R0 resection, and adverse events when compared with CESD.

Singh S ，Mohan BP ，Vinayek R ，Dutta S ，Dahiya DS ，Inamdar S ，Suresh Kumar VC ，Aswath G ，Sharma N ，Adler DG ... -  《-》

Usefulness of underwater endoscopic submucosal dissection in saline solution with a monopolar knife for colorectal tumors (with videos).

Generally, colorectal endoscopic submucosal dissection (ESD) is performed with a monopolar knife with CO2 supply from an endoscope. There are few case reports about underwater ESD (UESD) in saline solution with a bipolar knife. The usefulness and safety of UESD in saline solution with a monopolar knife are unclear. The present study aimed to investigate the usefulness and safety of UESD in saline solution with a monopolar knife for colorectal tumors. This retrospective, observational study on UESD for colorectal tumors included 26 colorectal tumors from 24 patients treated with UESD at our department between October 2015 and February 2017. The characteristics of patients, factors associated with ESD difficulty, treatment results, and variations in blood test data before and after UESD were analyzed. En bloc resection was successful in all lesions without any serious adverse events. The median major diameter of the resected specimens was 30 mm (interquartile range [IQR], 28-35) and of the tumor 22.5 mm (IQR, 17.8-25.3). The median procedure time was 60 minutes (IQR, 45-111) and median speed of dissection 10.4 mm2/min (IQR, 6.4-12.2). No cases of perforation occurred. Post-ESD bleeding occurred in only 1 case, and endoscopic hemostasis was achieved. There was no case of electrolyte imbalance requiring treatment after UESD. UESD in saline solution with a monopolar knife for colorectal tumors is useful and safe. UESD has potential advantages that should be further assessed.

Nagata M 《-》

Efficacy of traction-assisted colorectal endoscopic submucosal dissection using a clip-and-thread technique: A prospective randomized study.

Colorectal endoscopic submucosal dissection (ESD) remains challenging because of technical difficulties, long procedure time, and high risk of adverse events. To facilitate colorectal ESD, we developed traction-assisted colorectal ESD using a clip and thread (TAC-ESD) and conducted a randomized controlled trial to evaluate its efficacy. Patients with superficial colorectal neoplasms (SCN) ≥20 mm were enrolled and randomly assigned to the conventional-ESD group or to the TAC-ESD group. SCN ≤50 mm were treated by two intermediates, and SCN >50 mm were treated by two experts. Primary endpoint was procedure time. Secondary endpoints were TAC-ESD success rate (sustained application of the clip and thread until the end of the procedure), self-completion rate by the intermediates, and adverse events. Altogether, 42 SCN were analyzed in each ESD group (conventional and TAC). Procedure time (median [range]) for the TAC-ESD group was significantly shorter than that for the conventional-ESD group (40 [11-86] min vs 70 [30-180] min, respectively; P < 0.0001). Success rate of TAC-ESD was 95% (40/42). The intermediates' self-completion rate was significantly higher for the TAC-ESD group than for the conventional-ESD group (100% [39/39] vs 90% [36/40], respectively; P = 0.04). Adverse events included one intraoperative perforation in the conventional-ESD group and one delayed perforation in the TAC-ESD group. Traction-assisted colorectal endoscopic submucosal dissection reduced the procedure time and increased the self-completion rate by the intermediates (UMIN000018612).

Yamasaki Y ，Takeuchi Y ，Uedo N ，Kanesaka T ，Kato M ，Hamada K ，Tonai Y ，Matsuura N ，Akasaka T ，Hanaoka N ，Higashino K ，Ishihara R ，Okada H ，Iishi H ... -  《-》