An insert or elongate member divides the lumen of an elongated medical device, such as the working channel of an endoscope, into two or more secondary lumens. The insert or elongate member thereby improves the ability of the lumen of the elongated medical device to accommodate multiple items or uses. The insert or elongate member is capable of securing one item, such as a pull line, such that it does not interfere with another item positioned in the lumen of the elongated medical device or with another use of the lumen of the elongated medical device. In accordance with some embodiments, a ligating instrument comprises a ligating band dispenser, a pull line, and an elongate member having a dividing wall structure or a plurality of lumens, wherein the elongate member divides a working channel of an endoscope into a plurality of secondary lumens.
