Usefulness of a novel slim type FlushKnife-BT over conventional FlushKnife-BT in esophageal endoscopic submucosal dissection

Table 2 Outcomes of endoscopic submucosal dissection by novel slim type ball-tipped FlushKnife and ball-tipped FlushKnife

	FlushKnife-BT (n = 6)	FlushKnife-BTS (n = 7)	P vaule1
Use of the thread-traction method, yes/no	3/3	2/5	0.592
Procedure time, median (range), min	48 (24-106)	33 (27-51)	0.389
Treatment speed, median (range), mm2/min	25.5 (19.6-30.3)	44.2 (15.5-55.4)	0.0633
Number of times the knife was replaced, median (range), times	5.5 (4-10)	1 (0-3)	0.0025
Frequency of knife replacement, median (range), times/hour	7.02 (4.23-15)	1.76 (0-5.45)	0.0065
En bloc resection rate	6/6 (100%)	7/7 (100%)	0.000
Adverse events, Perforation/muscle injury/postoperative bleeding	0/1/0	0/0/0	0.462

¹The Mann-Whitney U test was used to compare continuous variables, and the χ² test or Fisher's exact probability test was used to compare categorical variables. FlushKnife-BT: Ball-tipped FlushKnife; FlushKnife-BTS: A novel slim type FlushKnife-BT.